Merge tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - A major update for DM cache that reduces the latency for deciding
   whether blocks should migrate to/from the cache. The bio-prison-v2
   interface supports this improvement by enabling direct dispatch of
   work to workqueues rather than having to delay the actual work
   dispatch to the DM cache core. So the dm-cache policies are much more
   nimble by being able to drive IO as they see fit. One immediate
   benefit from the improved latency is a cache that should be much more
   adaptive to changing workloads.

 - Add a new DM integrity target that emulates a block device that has
   additional per-sector tags that can be used for storing integrity
   information.

 - Add a new authenticated encryption feature to the DM crypt target
   that builds on the capabilities provided by the DM integrity target.

 - Add MD interface for switching the raid4/5/6 journal mode and update
   the DM raid target to use it to enable aid4/5/6 journal write-back
   support.

 - Switch the DM verity target over to using the asynchronous hash
   crypto API (this helps work better with architectures that have
   access to off-CPU algorithm providers, which should reduce CPU
   utilization).

 - Various request-based DM and DM multipath fixes and improvements from
   Bart and Christoph.

 - A DM thinp target fix for a bio structure leak that occurs for each
   discard IFF discard passdown is enabled.

 - A fix for a possible deadlock in DM bufio and a fix to re-check the
   new buffer allocation watermark in the face of competing admin
   changes to the 'max_cache_size_bytes' tunable.

 - A couple DM core cleanups.

* tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits)
  dm bufio: check new buffer allocation watermark every 30 seconds
  dm bufio: avoid a possible ABBA deadlock
  dm mpath: make it easier to detect unintended I/O request flushes
  dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()
  dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH
  dm: introduce enum dm_queue_mode to cleanup related code
  dm mpath: verify __pg_init_all_paths locking assumptions at runtime
  dm: verify suspend_locking assumptions at runtime
  dm block manager: remove an unused argument from dm_block_manager_create()
  dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()
  dm mpath: delay requeuing while path initialization is in progress
  dm mpath: avoid that path removal can trigger an infinite loop
  dm mpath: split and rename activate_path() to prepare for its expanded use
  dm ioctl: prevent stack leak in dm ioctl call
  dm integrity: use previously calculated log2 of sectors_per_block
  dm integrity: use hex2bin instead of open-coded variant
  dm crypt: replace custom implementation of hex2bin()
  dm crypt: remove obsolete references to per-CPU state
  dm verity: switch to using asynchronous hash crypto API
  dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues
  ...

41 files changed, 7330 insertions, 2983 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 585ff3284bf5..7468a22f9d10 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -325,14 +325,6 @@ config DM_CACHE_SMQ
          of less memory utilization, improved performance and increased
          adaptability in the face of changing workloads.
 
-config DM_CACHE_CLEANER
-       tristate "Cleaner Cache Policy (EXPERIMENTAL)"
-       depends on DM_CACHE
-       default y
-       ---help---
-         A simple cache policy that writes back all data to the
-         origin.  Used when decommissioning a dm-cache.
-
 config DM_ERA
        tristate "Era target (EXPERIMENTAL)"
        depends on BLK_DEV_DM
@@ -365,6 +357,7 @@ config DM_LOG_USERSPACE
 config DM_RAID
        tristate "RAID 1/4/5/6/10 target"
        depends on BLK_DEV_DM
+       select MD_RAID0
        select MD_RAID1
        select MD_RAID10
        select MD_RAID456
@@ -508,4 +501,14 @@ config DM_LOG_WRITES
 
 	  If unsure, say N.
 
+config DM_INTEGRITY
+	tristate "Integrity target"
+	depends on BLK_DEV_DM
+	select BLK_DEV_INTEGRITY
+	select DM_BUFIO
+	select CRYPTO
+	select ASYNC_XOR
+	---help---
+	   This is the integrity target.
+
 endif # MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 4d48714ccc6b..913720bd81c1 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -11,10 +11,11 @@ dm-snapshot-y	+= dm-snap.o dm-exception-store.o dm-snap-transient.o \
 dm-mirror-y	+= dm-raid1.o
 dm-log-userspace-y \
 		+= dm-log-userspace-base.o dm-log-userspace-transfer.o
+dm-bio-prison-y += dm-bio-prison-v1.o dm-bio-prison-v2.o
 dm-thin-pool-y	+= dm-thin.o dm-thin-metadata.o
-dm-cache-y	+= dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o
+dm-cache-y	+= dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o \
+		    dm-cache-background-tracker.o
 dm-cache-smq-y   += dm-cache-policy-smq.o
-dm-cache-cleaner-y += dm-cache-policy-cleaner.o
 dm-era-y	+= dm-era-target.o
 dm-verity-y	+= dm-verity-target.o
 md-mod-y	+= md.o bitmap.o
@@ -56,9 +57,9 @@ obj-$(CONFIG_DM_THIN_PROVISIONING)	+= dm-thin-pool.o
 obj-$(CONFIG_DM_VERITY)		+= dm-verity.o
 obj-$(CONFIG_DM_CACHE)		+= dm-cache.o
 obj-$(CONFIG_DM_CACHE_SMQ)	+= dm-cache-smq.o
-obj-$(CONFIG_DM_CACHE_CLEANER)	+= dm-cache-cleaner.o
 obj-$(CONFIG_DM_ERA)		+= dm-era.o
 obj-$(CONFIG_DM_LOG_WRITES)	+= dm-log-writes.o
+obj-$(CONFIG_DM_INTEGRITY)	+= dm-integrity.o
 
 ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison-v1.c
index 03af174485d3..ae7da2c30a57 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison-v1.c
@@ -5,7 +5,8 @@
  */
 
 #include "dm.h"
-#include "dm-bio-prison.h"
+#include "dm-bio-prison-v1.h"
+#include "dm-bio-prison-v2.h"
 
 #include <linux/spinlock.h>
 #include <linux/mempool.h>
@@ -398,7 +399,7 @@ EXPORT_SYMBOL_GPL(dm_deferred_set_add_work);
 
 /*----------------------------------------------------------------*/
 
-static int __init dm_bio_prison_init(void)
+static int __init dm_bio_prison_init_v1(void)
 {
 	_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);
 	if (!_cell_cache)
@@ -407,12 +408,51 @@ static int __init dm_bio_prison_init(void)
 	return 0;
 }
 
-static void __exit dm_bio_prison_exit(void)
+static void dm_bio_prison_exit_v1(void)
 {
 	kmem_cache_destroy(_cell_cache);
 	_cell_cache = NULL;
 }
 
+static int (*_inits[])(void) __initdata = {
+	dm_bio_prison_init_v1,
+	dm_bio_prison_init_v2,
+};
+
+static void (*_exits[])(void) = {
+	dm_bio_prison_exit_v1,
+	dm_bio_prison_exit_v2,
+};
+
+static int __init dm_bio_prison_init(void)
+{
+	const int count = ARRAY_SIZE(_inits);
+
+	int r, i;
+
+	for (i = 0; i < count; i++) {
+		r = _inits[i]();
+		if (r)
+			goto bad;
+	}
+
+	return 0;
+
+      bad:
+	while (i--)
+		_exits[i]();
+
+	return r;
+}
+
+static void __exit dm_bio_prison_exit(void)
+{
+	int i = ARRAY_SIZE(_exits);
+
+	while (i--)
+		_exits[i]();
+}
+
 /*
  * module hooks
  */
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison-v1.h
index 54352f009bfd..cddd4ac07e2c 100644
--- a/drivers/md/dm-bio-prison.h
+++ b/drivers/md/dm-bio-prison-v1.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011-2012 Red Hat, Inc.
+ * Copyright (C) 2011-2017 Red Hat, Inc.
  *
  * This file is released under the GPL.
  */
diff --git a/drivers/md/dm-bio-prison-v2.c b/drivers/md/dm-bio-prison-v2.c
new file mode 100644
index 000000000000..c9b11f799cd8
--- /dev/null
+++ b/drivers/md/dm-bio-prison-v2.c
@@ -0,0 +1,369 @@
+/*
+ * Copyright (C) 2012-2017 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+#include "dm-bio-prison-v2.h"
+
+#include <linux/spinlock.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/rwsem.h>
+
+/*----------------------------------------------------------------*/
+
+#define MIN_CELLS 1024
+
+struct dm_bio_prison_v2 {
+	struct workqueue_struct *wq;
+
+	spinlock_t lock;
+	mempool_t *cell_pool;
+	struct rb_root cells;
+};
+
+static struct kmem_cache *_cell_cache;
+
+/*----------------------------------------------------------------*/
+
+/*
+ * @nr_cells should be the number of cells you want in use _concurrently_.
+ * Don't confuse it with the number of distinct keys.
+ */
+struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq)
+{
+	struct dm_bio_prison_v2 *prison = kmalloc(sizeof(*prison), GFP_KERNEL);
+
+	if (!prison)
+		return NULL;
+
+	prison->wq = wq;
+	spin_lock_init(&prison->lock);
+
+	prison->cell_pool = mempool_create_slab_pool(MIN_CELLS, _cell_cache);
+	if (!prison->cell_pool) {
+		kfree(prison);
+		return NULL;
+	}
+
+	prison->cells = RB_ROOT;
+
+	return prison;
+}
+EXPORT_SYMBOL_GPL(dm_bio_prison_create_v2);
+
+void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison)
+{
+	mempool_destroy(prison->cell_pool);
+	kfree(prison);
+}
+EXPORT_SYMBOL_GPL(dm_bio_prison_destroy_v2);
+
+struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison, gfp_t gfp)
+{
+	return mempool_alloc(prison->cell_pool, gfp);
+}
+EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell_v2);
+
+void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison,
+				struct dm_bio_prison_cell_v2 *cell)
+{
+	mempool_free(cell, prison->cell_pool);
+}
+EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell_v2);
+
+static void __setup_new_cell(struct dm_cell_key_v2 *key,
+			     struct dm_bio_prison_cell_v2 *cell)
+{
+	memset(cell, 0, sizeof(*cell));
+	memcpy(&cell->key, key, sizeof(cell->key));
+	bio_list_init(&cell->bios);
+}
+
+static int cmp_keys(struct dm_cell_key_v2 *lhs,
+		    struct dm_cell_key_v2 *rhs)
+{
+	if (lhs->virtual < rhs->virtual)
+		return -1;
+
+	if (lhs->virtual > rhs->virtual)
+		return 1;
+
+	if (lhs->dev < rhs->dev)
+		return -1;
+
+	if (lhs->dev > rhs->dev)
+		return 1;
+
+	if (lhs->block_end <= rhs->block_begin)
+		return -1;
+
+	if (lhs->block_begin >= rhs->block_end)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Returns true if node found, otherwise it inserts a new one.
+ */
+static bool __find_or_insert(struct dm_bio_prison_v2 *prison,
+			     struct dm_cell_key_v2 *key,
+			     struct dm_bio_prison_cell_v2 *cell_prealloc,
+			     struct dm_bio_prison_cell_v2 **result)
+{
+	int r;
+	struct rb_node **new = &prison->cells.rb_node, *parent = NULL;
+
+	while (*new) {
+		struct dm_bio_prison_cell_v2 *cell =
+			container_of(*new, struct dm_bio_prison_cell_v2, node);
+
+		r = cmp_keys(key, &cell->key);
+
+		parent = *new;
+		if (r < 0)
+			new = &((*new)->rb_left);
+
+		else if (r > 0)
+			new = &((*new)->rb_right);
+
+		else {
+			*result = cell;
+			return true;
+		}
+	}
+
+	__setup_new_cell(key, cell_prealloc);
+	*result = cell_prealloc;
+	rb_link_node(&cell_prealloc->node, parent, new);
+	rb_insert_color(&cell_prealloc->node, &prison->cells);
+
+	return false;
+}
+
+static bool __get(struct dm_bio_prison_v2 *prison,
+		  struct dm_cell_key_v2 *key,
+		  unsigned lock_level,
+		  struct bio *inmate,
+		  struct dm_bio_prison_cell_v2 *cell_prealloc,
+		  struct dm_bio_prison_cell_v2 **cell)
+{
+	if (__find_or_insert(prison, key, cell_prealloc, cell)) {
+		if ((*cell)->exclusive_lock) {
+			if (lock_level <= (*cell)->exclusive_level) {
+				bio_list_add(&(*cell)->bios, inmate);
+				return false;
+			}
+		}
+
+		(*cell)->shared_count++;
+
+	} else
+		(*cell)->shared_count = 1;
+
+	return true;
+}
+
+bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_cell_key_v2 *key,
+		    unsigned lock_level,
+		    struct bio *inmate,
+		    struct dm_bio_prison_cell_v2 *cell_prealloc,
+		    struct dm_bio_prison_cell_v2 **cell_result)
+{
+	int r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __get(prison, key, lock_level, inmate, cell_prealloc, cell_result);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_get_v2);
+
+static bool __put(struct dm_bio_prison_v2 *prison,
+		  struct dm_bio_prison_cell_v2 *cell)
+{
+	BUG_ON(!cell->shared_count);
+	cell->shared_count--;
+
+	// FIXME: shared locks granted above the lock level could starve this
+	if (!cell->shared_count) {
+		if (cell->exclusive_lock){
+			if (cell->quiesce_continuation) {
+				queue_work(prison->wq, cell->quiesce_continuation);
+				cell->quiesce_continuation = NULL;
+			}
+		} else {
+			rb_erase(&cell->node, &prison->cells);
+			return true;
+		}
+	}
+
+	return false;
+}
+
+bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_bio_prison_cell_v2 *cell)
+{
+	bool r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __put(prison, cell);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_put_v2);
+
+static int __lock(struct dm_bio_prison_v2 *prison,
+		  struct dm_cell_key_v2 *key,
+		  unsigned lock_level,
+		  struct dm_bio_prison_cell_v2 *cell_prealloc,
+		  struct dm_bio_prison_cell_v2 **cell_result)
+{
+	struct dm_bio_prison_cell_v2 *cell;
+
+	if (__find_or_insert(prison, key, cell_prealloc, &cell)) {
+		if (cell->exclusive_lock)
+			return -EBUSY;
+
+		cell->exclusive_lock = true;
+		cell->exclusive_level = lock_level;
+		*cell_result = cell;
+
+		// FIXME: we don't yet know what level these shared locks
+		// were taken at, so have to quiesce them all.
+		return cell->shared_count > 0;
+
+	} else {
+		cell = cell_prealloc;
+		cell->shared_count = 0;
+		cell->exclusive_lock = true;
+		cell->exclusive_level = lock_level;
+		*cell_result = cell;
+	}
+
+	return 0;
+}
+
+int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_cell_key_v2 *key,
+		    unsigned lock_level,
+		    struct dm_bio_prison_cell_v2 *cell_prealloc,
+		    struct dm_bio_prison_cell_v2 **cell_result)
+{
+	int r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __lock(prison, key, lock_level, cell_prealloc, cell_result);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_lock_v2);
+
+static void __quiesce(struct dm_bio_prison_v2 *prison,
+		      struct dm_bio_prison_cell_v2 *cell,
+		      struct work_struct *continuation)
+{
+	if (!cell->shared_count)
+		queue_work(prison->wq, continuation);
+	else
+		cell->quiesce_continuation = continuation;
+}
+
+void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison,
+			struct dm_bio_prison_cell_v2 *cell,
+			struct work_struct *continuation)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	__quiesce(prison, cell, continuation);
+	spin_unlock_irqrestore(&prison->lock, flags);
+}
+EXPORT_SYMBOL_GPL(dm_cell_quiesce_v2);
+
+static int __promote(struct dm_bio_prison_v2 *prison,
+		     struct dm_bio_prison_cell_v2 *cell,
+		     unsigned new_lock_level)
+{
+	if (!cell->exclusive_lock)
+		return -EINVAL;
+
+	cell->exclusive_level = new_lock_level;
+	return cell->shared_count > 0;
+}
+
+int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison,
+			    struct dm_bio_prison_cell_v2 *cell,
+			    unsigned new_lock_level)
+{
+	int r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __promote(prison, cell, new_lock_level);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_lock_promote_v2);
+
+static bool __unlock(struct dm_bio_prison_v2 *prison,
+		     struct dm_bio_prison_cell_v2 *cell,
+		     struct bio_list *bios)
+{
+	BUG_ON(!cell->exclusive_lock);
+
+	bio_list_merge(bios, &cell->bios);
+	bio_list_init(&cell->bios);
+
+	if (cell->shared_count) {
+		cell->exclusive_lock = 0;
+		return false;
+	}
+
+	rb_erase(&cell->node, &prison->cells);
+	return true;
+}
+
+bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison,
+		       struct dm_bio_prison_cell_v2 *cell,
+		       struct bio_list *bios)
+{
+	bool r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prison->lock, flags);
+	r = __unlock(prison, cell, bios);
+	spin_unlock_irqrestore(&prison->lock, flags);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(dm_cell_unlock_v2);
+
+/*----------------------------------------------------------------*/
+
+int __init dm_bio_prison_init_v2(void)
+{
+	_cell_cache = KMEM_CACHE(dm_bio_prison_cell_v2, 0);
+	if (!_cell_cache)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void dm_bio_prison_exit_v2(void)
+{
+	kmem_cache_destroy(_cell_cache);
+	_cell_cache = NULL;
+}
diff --git a/drivers/md/dm-bio-prison-v2.h b/drivers/md/dm-bio-prison-v2.h
new file mode 100644
index 000000000000..6e04234268db
--- /dev/null
+++ b/drivers/md/dm-bio-prison-v2.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2011-2017 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_BIO_PRISON_V2_H
+#define DM_BIO_PRISON_V2_H
+
+#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */
+#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */
+
+#include <linux/bio.h>
+#include <linux/rbtree.h>
+#include <linux/workqueue.h>
+
+/*----------------------------------------------------------------*/
+
+int dm_bio_prison_init_v2(void);
+void dm_bio_prison_exit_v2(void);
+
+/*
+ * Sometimes we can't deal with a bio straight away.  We put them in prison
+ * where they can't cause any mischief.  Bios are put in a cell identified
+ * by a key, multiple bios can be in the same cell.  When the cell is
+ * subsequently unlocked the bios become available.
+ */
+struct dm_bio_prison_v2;
+
+/*
+ * Keys define a range of blocks within either a virtual or physical
+ * device.
+ */
+struct dm_cell_key_v2 {
+	int virtual;
+	dm_thin_id dev;
+	dm_block_t block_begin, block_end;
+};
+
+/*
+ * Treat this as opaque, only in header so callers can manage allocation
+ * themselves.
+ */
+struct dm_bio_prison_cell_v2 {
+	// FIXME: pack these
+	bool exclusive_lock;
+	unsigned exclusive_level;
+	unsigned shared_count;
+	struct work_struct *quiesce_continuation;
+
+	struct rb_node node;
+	struct dm_cell_key_v2 key;
+	struct bio_list bios;
+};
+
+struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq);
+void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison);
+
+/*
+ * These two functions just wrap a mempool.  This is a transitory step:
+ * Eventually all bio prison clients should manage their own cell memory.
+ *
+ * Like mempool_alloc(), dm_bio_prison_alloc_cell_v2() can only fail if called
+ * in interrupt context or passed GFP_NOWAIT.
+ */
+struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison,
+						    gfp_t gfp);
+void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison,
+				struct dm_bio_prison_cell_v2 *cell);
+
+/*
+ * Shared locks have a bio associated with them.
+ *
+ * If the lock is granted the caller can continue to use the bio, and must
+ * call dm_cell_put_v2() to drop the reference count when finished using it.
+ *
+ * If the lock cannot be granted then the bio will be tracked within the
+ * cell, and later given to the holder of the exclusive lock.
+ *
+ * See dm_cell_lock_v2() for discussion of the lock_level parameter.
+ *
+ * Compare *cell_result with cell_prealloc to see if the prealloc was used.
+ * If cell_prealloc was used then inmate wasn't added to it.
+ *
+ * Returns true if the lock is granted.
+ */
+bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_cell_key_v2 *key,
+		    unsigned lock_level,
+		    struct bio *inmate,
+		    struct dm_bio_prison_cell_v2 *cell_prealloc,
+		    struct dm_bio_prison_cell_v2 **cell_result);
+
+/*
+ * Decrement the shared reference count for the lock.  Returns true if
+ * returning ownership of the cell (ie. you should free it).
+ */
+bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_bio_prison_cell_v2 *cell);
+
+/*
+ * Locks a cell.  No associated bio.  Exclusive locks get priority.  These
+ * locks constrain whether the io locks are granted according to level.
+ *
+ * Shared locks will still be granted if the lock_level is > (not = to) the
+ * exclusive lock level.
+ *
+ * If an _exclusive_ lock is already held then -EBUSY is returned.
+ *
+ * Return values:
+ *  < 0 - error
+ *  0   - locked; no quiescing needed
+ *  1   - locked; quiescing needed
+ */
+int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison,
+		    struct dm_cell_key_v2 *key,
+		    unsigned lock_level,
+		    struct dm_bio_prison_cell_v2 *cell_prealloc,
+		    struct dm_bio_prison_cell_v2 **cell_result);
+
+void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison,
+			struct dm_bio_prison_cell_v2 *cell,
+			struct work_struct *continuation);
+
+/*
+ * Promotes an _exclusive_ lock to a higher lock level.
+ *
+ * Return values:
+ *  < 0 - error
+ *  0   - promoted; no quiescing needed
+ *  1   - promoted; quiescing needed
+ */
+int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison,
+			    struct dm_bio_prison_cell_v2 *cell,
+			    unsigned new_lock_level);
+
+/*
+ * Adds any held bios to the bio list.
+ *
+ * There may be shared locks still held at this point even if you quiesced
+ * (ie. different lock levels).
+ *
+ * Returns true if returning ownership of the cell (ie. you should free
+ * it).
+ */
+bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison,
+		       struct dm_bio_prison_cell_v2 *cell,
+		       struct bio_list *bios);
+
+/*----------------------------------------------------------------*/
+
+#endif
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index df4859f6ac6a..c92c31b23e54 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -110,6 +110,8 @@ struct dm_bufio_client {
 	struct rb_root buffer_tree;
 	wait_queue_head_t free_buffer_wait;
 
+	sector_t start;
+
 	int async_write_error;
 
 	struct list_head client_list;
@@ -557,8 +559,8 @@ static void dmio_complete(unsigned long error, void *context)
 	b->bio.bi_end_io(&b->bio);
 }
 
-static void use_dmio(struct dm_buffer *b, int rw, sector_t block,
-		     bio_end_io_t *end_io)
+static void use_dmio(struct dm_buffer *b, int rw, sector_t sector,
+		     unsigned n_sectors, bio_end_io_t *end_io)
 {
 	int r;
 	struct dm_io_request io_req = {
@@ -570,8 +572,8 @@ static void use_dmio(struct dm_buffer *b, int rw, sector_t block,
 	};
 	struct dm_io_region region = {
 		.bdev = b->c->bdev,
-		.sector = block << b->c->sectors_per_block_bits,
-		.count = b->c->block_size >> SECTOR_SHIFT,
+		.sector = sector,
+		.count = n_sectors,
 	};
 
 	if (b->data_mode != DATA_MODE_VMALLOC) {
@@ -606,14 +608,14 @@ static void inline_endio(struct bio *bio)
 	end_fn(bio);
 }
 
-static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,
-			   bio_end_io_t *end_io)
+static void use_inline_bio(struct dm_buffer *b, int rw, sector_t sector,
+			   unsigned n_sectors, bio_end_io_t *end_io)
 {
 	char *ptr;
 	int len;
 
 	bio_init(&b->bio, b->bio_vec, DM_BUFIO_INLINE_VECS);
-	b->bio.bi_iter.bi_sector = block << b->c->sectors_per_block_bits;
+	b->bio.bi_iter.bi_sector = sector;
 	b->bio.bi_bdev = b->c->bdev;
 	b->bio.bi_end_io = inline_endio;
 	/*
@@ -628,7 +630,7 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,
 	 * If len < PAGE_SIZE the buffer doesn't cross page boundary.
 	 */
 	ptr = b->data;
-	len = b->c->block_size;
+	len = n_sectors << SECTOR_SHIFT;
 
 	if (len >= PAGE_SIZE)
 		BUG_ON((unsigned long)ptr & (PAGE_SIZE - 1));
@@ -640,7 +642,7 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,
 				  len < PAGE_SIZE ? len : PAGE_SIZE,
 				  offset_in_page(ptr))) {
 			BUG_ON(b->c->block_size <= PAGE_SIZE);
-			use_dmio(b, rw, block, end_io);
+			use_dmio(b, rw, sector, n_sectors, end_io);
 			return;
 		}
 
@@ -651,17 +653,22 @@ static void use_inline_bio(struct dm_buffer *b, int rw, sector_t block,
 	submit_bio(&b->bio);
 }
 
-static void submit_io(struct dm_buffer *b, int rw, sector_t block,
-		      bio_end_io_t *end_io)
+static void submit_io(struct dm_buffer *b, int rw, bio_end_io_t *end_io)
 {
+	unsigned n_sectors;
+	sector_t sector;
+
 	if (rw == WRITE && b->c->write_callback)
 		b->c->write_callback(b);
 
-	if (b->c->block_size <= DM_BUFIO_INLINE_VECS * PAGE_SIZE &&
+	sector = (b->block << b->c->sectors_per_block_bits) + b->c->start;
+	n_sectors = 1 << b->c->sectors_per_block_bits;
+
+	if (n_sectors <= ((DM_BUFIO_INLINE_VECS * PAGE_SIZE) >> SECTOR_SHIFT) &&
 	    b->data_mode != DATA_MODE_VMALLOC)
-		use_inline_bio(b, rw, block, end_io);
+		use_inline_bio(b, rw, sector, n_sectors, end_io);
 	else
-		use_dmio(b, rw, block, end_io);
+		use_dmio(b, rw, sector, n_sectors, end_io);
 }
 
 /*----------------------------------------------------------------
@@ -713,7 +720,7 @@ static void __write_dirty_buffer(struct dm_buffer *b,
 	wait_on_bit_lock_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
 
 	if (!write_list)
-		submit_io(b, WRITE, b->block, write_endio);
+		submit_io(b, WRITE, write_endio);
 	else
 		list_add_tail(&b->write_list, write_list);
 }
@@ -726,7 +733,7 @@ static void __flush_write_list(struct list_head *write_list)
 		struct dm_buffer *b =
 			list_entry(write_list->next, struct dm_buffer, write_list);
 		list_del(&b->write_list);
-		submit_io(b, WRITE, b->block, write_endio);
+		submit_io(b, WRITE, write_endio);
 		cond_resched();
 	}
 	blk_finish_plug(&plug);
@@ -933,10 +940,11 @@ static void __get_memory_limit(struct dm_bufio_client *c,
 {
 	unsigned long buffers;
 
-	if (ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch) {
-		mutex_lock(&dm_bufio_clients_lock);
-		__cache_size_refresh();
-		mutex_unlock(&dm_bufio_clients_lock);
+	if (unlikely(ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch)) {
+		if (mutex_trylock(&dm_bufio_clients_lock)) {
+			__cache_size_refresh();
+			mutex_unlock(&dm_bufio_clients_lock);
+		}
 	}
 
 	buffers = dm_bufio_cache_size_per_client >>
@@ -1094,7 +1102,7 @@ static void *new_read(struct dm_bufio_client *c, sector_t block,
 		return NULL;
 
 	if (need_submit)
-		submit_io(b, READ, b->block, read_endio);
+		submit_io(b, READ, read_endio);
 
 	wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
 
@@ -1164,7 +1172,7 @@ void dm_bufio_prefetch(struct dm_bufio_client *c,
 			dm_bufio_unlock(c);
 
 			if (need_submit)
-				submit_io(b, READ, b->block, read_endio);
+				submit_io(b, READ, read_endio);
 			dm_bufio_release(b);
 
 			cond_resched();
@@ -1405,7 +1413,7 @@ retry:
 		old_block = b->block;
 		__unlink_buffer(b);
 		__link_buffer(b, new_block, b->list_mode);
-		submit_io(b, WRITE, new_block, write_endio);
+		submit_io(b, WRITE, write_endio);
 		wait_on_bit_io(&b->state, B_WRITING,
 			       TASK_UNINTERRUPTIBLE);
 		__unlink_buffer(b);
@@ -1762,6 +1770,12 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c)
 }
 EXPORT_SYMBOL_GPL(dm_bufio_client_destroy);
 
+void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start)
+{
+	c->start = start;
+}
+EXPORT_SYMBOL_GPL(dm_bufio_set_sector_offset);
+
 static unsigned get_max_age_hz(void)
 {
 	unsigned max_age = ACCESS_ONCE(dm_bufio_max_age);
@@ -1782,9 +1796,17 @@ static void __evict_old_buffers(struct dm_bufio_client *c, unsigned long age_hz)
 	struct dm_buffer *b, *tmp;
 	unsigned retain_target = get_retain_buffers(c);
 	unsigned count;
+	LIST_HEAD(write_list);
 
 	dm_bufio_lock(c);
 
+	__check_watermark(c, &write_list);
+	if (unlikely(!list_empty(&write_list))) {
+		dm_bufio_unlock(c);
+		__flush_write_list(&write_list);
+		dm_bufio_lock(c);
+	}
+
 	count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
 	list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_CLEAN], lru_list) {
 		if (count <= retain_target)
@@ -1809,6 +1831,8 @@ static void cleanup_old_buffers(void)
 
 	mutex_lock(&dm_bufio_clients_lock);
 
+	__cache_size_refresh();
+
 	list_for_each_entry(c, &dm_bufio_all_clients, client_list)
 		__evict_old_buffers(c, max_age_hz);
 
diff --git a/drivers/md/dm-bufio.h b/drivers/md/dm-bufio.h
index c096779a7292..b6d8f53ec15b 100644
--- a/drivers/md/dm-bufio.h
+++ b/drivers/md/dm-bufio.h
@@ -32,6 +32,13 @@ dm_bufio_client_create(struct block_device *bdev, unsigned block_size,
 void dm_bufio_client_destroy(struct dm_bufio_client *c);
 
 /*
+ * Set the sector range.
+ * When this function is called, there must be no I/O in progress on the bufio
+ * client.
+ */
+void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start);
+
+/*
  * WARNING: to avoid deadlocks, these conditions are observed:
  *
  * - At most one thread can hold at most "reserved_buffers" simultaneously.
diff --git a/drivers/md/dm-cache-background-tracker.c b/drivers/md/dm-cache-background-tracker.c
new file mode 100644
index 000000000000..9b1afdfb13f0
--- /dev/null
+++ b/drivers/md/dm-cache-background-tracker.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2017 Red Hat. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-cache-background-tracker.h"
+
+/*----------------------------------------------------------------*/
+
+#define DM_MSG_PREFIX "dm-background-tracker"
+
+struct bt_work {
+	struct list_head list;
+	struct rb_node node;
+	struct policy_work work;
+};
+
+struct background_tracker {
+	unsigned max_work;
+	atomic_t pending_promotes;
+	atomic_t pending_writebacks;
+	atomic_t pending_demotes;
+
+	struct list_head issued;
+	struct list_head queued;
+	struct rb_root pending;
+
+	struct kmem_cache *work_cache;
+};
+
+struct background_tracker *btracker_create(unsigned max_work)
+{
+	struct background_tracker *b = kmalloc(sizeof(*b), GFP_KERNEL);
+
+	b->max_work = max_work;
+	atomic_set(&b->pending_promotes, 0);
+	atomic_set(&b->pending_writebacks, 0);
+	atomic_set(&b->pending_demotes, 0);
+
+	INIT_LIST_HEAD(&b->issued);
+	INIT_LIST_HEAD(&b->queued);
+
+	b->pending = RB_ROOT;
+	b->work_cache = KMEM_CACHE(bt_work, 0);
+	if (!b->work_cache) {
+		DMERR("couldn't create mempool for background work items");
+		kfree(b);
+		b = NULL;
+	}
+
+	return b;
+}
+EXPORT_SYMBOL_GPL(btracker_create);
+
+void btracker_destroy(struct background_tracker *b)
+{
+	kmem_cache_destroy(b->work_cache);
+	kfree(b);
+}
+EXPORT_SYMBOL_GPL(btracker_destroy);
+
+static int cmp_oblock(dm_oblock_t lhs, dm_oblock_t rhs)
+{
+	if (from_oblock(lhs) < from_oblock(rhs))
+		return -1;
+
+	if (from_oblock(rhs) < from_oblock(lhs))
+		return 1;
+
+	return 0;
+}
+
+static bool __insert_pending(struct background_tracker *b,
+			     struct bt_work *nw)
+{
+	int cmp;
+	struct bt_work *w;
+	struct rb_node **new = &b->pending.rb_node, *parent = NULL;
+
+	while (*new) {
+		w = container_of(*new, struct bt_work, node);
+
+		parent = *new;
+		cmp = cmp_oblock(w->work.oblock, nw->work.oblock);
+		if (cmp < 0)
+			new = &((*new)->rb_left);
+
+		else if (cmp > 0)
+			new = &((*new)->rb_right);
+
+		else
+			/* already present */
+			return false;
+	}
+
+	rb_link_node(&nw->node, parent, new);
+	rb_insert_color(&nw->node, &b->pending);
+
+	return true;
+}
+
+static struct bt_work *__find_pending(struct background_tracker *b,
+				      dm_oblock_t oblock)
+{
+	int cmp;
+	struct bt_work *w;
+	struct rb_node **new = &b->pending.rb_node;
+
+	while (*new) {
+		w = container_of(*new, struct bt_work, node);
+
+		cmp = cmp_oblock(w->work.oblock, oblock);
+		if (cmp < 0)
+			new = &((*new)->rb_left);
+
+		else if (cmp > 0)
+			new = &((*new)->rb_right);
+
+		else
+			break;
+	}
+
+	return *new ? w : NULL;
+}
+
+
+static void update_stats(struct background_tracker *b, struct policy_work *w, int delta)
+{
+	switch (w->op) {
+	case POLICY_PROMOTE:
+		atomic_add(delta, &b->pending_promotes);
+		break;
+
+	case POLICY_DEMOTE:
+		atomic_add(delta, &b->pending_demotes);
+		break;
+
+	case POLICY_WRITEBACK:
+		atomic_add(delta, &b->pending_writebacks);
+		break;
+	}
+}
+
+unsigned btracker_nr_writebacks_queued(struct background_tracker *b)
+{
+	return atomic_read(&b->pending_writebacks);
+}
+EXPORT_SYMBOL_GPL(btracker_nr_writebacks_queued);
+
+unsigned btracker_nr_demotions_queued(struct background_tracker *b)
+{
+	return atomic_read(&b->pending_demotes);
+}
+EXPORT_SYMBOL_GPL(btracker_nr_demotions_queued);
+
+static bool max_work_reached(struct background_tracker *b)
+{
+	// FIXME: finish
+	return false;
+}
+
+int btracker_queue(struct background_tracker *b,
+		   struct policy_work *work,
+		   struct policy_work **pwork)
+{
+	struct bt_work *w;
+
+	if (pwork)
+		*pwork = NULL;
+
+	if (max_work_reached(b))
+		return -ENOMEM;
+
+	w = kmem_cache_alloc(b->work_cache, GFP_NOWAIT);
+	if (!w)
+		return -ENOMEM;
+
+	memcpy(&w->work, work, sizeof(*work));
+
+	if (!__insert_pending(b, w)) {
+		/*
+		 * There was a race, we'll just ignore this second
+		 * bit of work for the same oblock.
+		 */
+		kmem_cache_free(b->work_cache, w);
+		return -EINVAL;
+	}
+
+	if (pwork) {
+		*pwork = &w->work;
+		list_add(&w->list, &b->issued);
+	} else
+		list_add(&w->list, &b->queued);
+	update_stats(b, &w->work, 1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btracker_queue);
+
+/*
+ * Returns -ENODATA if there's no work.
+ */
+int btracker_issue(struct background_tracker *b, struct policy_work **work)
+{
+	struct bt_work *w;
+
+	if (list_empty(&b->queued))
+		return -ENODATA;
+
+	w = list_first_entry(&b->queued, struct bt_work, list);
+	list_move(&w->list, &b->issued);
+	*work = &w->work;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btracker_issue);
+
+void btracker_complete(struct background_tracker *b,
+		       struct policy_work *op)
+{
+	struct bt_work *w = container_of(op, struct bt_work, work);
+
+	update_stats(b, &w->work, -1);
+	rb_erase(&w->node, &b->pending);
+	list_del(&w->list);
+	kmem_cache_free(b->work_cache, w);
+}
+EXPORT_SYMBOL_GPL(btracker_complete);
+
+bool btracker_promotion_already_present(struct background_tracker *b,
+					dm_oblock_t oblock)
+{
+	return __find_pending(b, oblock) != NULL;
+}
+EXPORT_SYMBOL_GPL(btracker_promotion_already_present);
+
+/*----------------------------------------------------------------*/
diff --git a/drivers/md/dm-cache-background-tracker.h b/drivers/md/dm-cache-background-tracker.h
new file mode 100644
index 000000000000..27ab90dbc275
--- /dev/null
+++ b/drivers/md/dm-cache-background-tracker.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2017 Red Hat. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_CACHE_BACKGROUND_WORK_H
+#define DM_CACHE_BACKGROUND_WORK_H
+
+#include <linux/vmalloc.h>
+#include "dm-cache-policy.h"
+
+/*----------------------------------------------------------------*/
+
+struct background_work;
+struct background_tracker;
+
+/*
+ * FIXME: discuss lack of locking in all methods.
+ */
+struct background_tracker *btracker_create(unsigned max_work);
+void btracker_destroy(struct background_tracker *b);
+
+unsigned btracker_nr_writebacks_queued(struct background_tracker *b);
+unsigned btracker_nr_demotions_queued(struct background_tracker *b);
+
+/*
+ * returns -EINVAL iff the work is already queued.  -ENOMEM if the work
+ * couldn't be queued for another reason.
+ */
+int btracker_queue(struct background_tracker *b,
+		   struct policy_work *work,
+		   struct policy_work **pwork);
+
+/*
+ * Returns -ENODATA if there's no work.
+ */
+int btracker_issue(struct background_tracker *b, struct policy_work **work);
+void btracker_complete(struct background_tracker *b,
+		       struct policy_work *op);
+bool btracker_promotion_already_present(struct background_tracker *b,
+					dm_oblock_t oblock);
+
+/*----------------------------------------------------------------*/
+
+#endif
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 6735c8d6a445..8568dbd50ba4 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -27,8 +27,6 @@
 #define MIN_CACHE_VERSION 1
 #define MAX_CACHE_VERSION 2
 
-#define CACHE_METADATA_CACHE_SIZE 64
-
 /*
  *  3 for btree insert +
  *  2 for btree lookup used within space map
@@ -535,7 +533,6 @@ static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
 {
 	int r;
 	cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
-					  CACHE_METADATA_CACHE_SIZE,
 					  CACHE_MAX_CONCURRENT_LOCKS);
 	if (IS_ERR(cmd->bm)) {
 		DMERR("could not create block manager");
diff --git a/drivers/md/dm-cache-metadata.h b/drivers/md/dm-cache-metadata.h
index 4f07c08cf107..179ed5bf81a3 100644
--- a/drivers/md/dm-cache-metadata.h
+++ b/drivers/md/dm-cache-metadata.h
@@ -50,6 +50,8 @@
 #define DM_CACHE_FEATURE_COMPAT_RO_SUPP	  0UL
 #define DM_CACHE_FEATURE_INCOMPAT_SUPP	  0UL
 
+struct dm_cache_metadata;
+
 /*
  * Reopens or creates a new, empty metadata volume.  Returns an ERR_PTR on
  * failure.  If reopening then features must match.
diff --git a/drivers/md/dm-cache-policy-cleaner.c b/drivers/md/dm-cache-policy-cleaner.c
deleted file mode 100644
index 2e8a8f1d8358..000000000000
--- a/drivers/md/dm-cache-policy-cleaner.c
+++ /dev/null
@@ -1,469 +0,0 @@
-/*
- * Copyright (C) 2012 Red Hat. All rights reserved.
- *
- * writeback cache policy supporting flushing out dirty cache blocks.
- *
- * This file is released under the GPL.
- */
-
-#include "dm-cache-policy.h"
-#include "dm.h"
-
-#include <linux/hash.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-
-/*----------------------------------------------------------------*/
-
-#define DM_MSG_PREFIX "cache cleaner"
-
-/* Cache entry struct. */
-struct wb_cache_entry {
-	struct list_head list;
-	struct hlist_node hlist;
-
-	dm_oblock_t oblock;
-	dm_cblock_t cblock;
-	bool dirty:1;
-	bool pending:1;
-};
-
-struct hash {
-	struct hlist_head *table;
-	dm_block_t hash_bits;
-	unsigned nr_buckets;
-};
-
-struct policy {
-	struct dm_cache_policy policy;
-	spinlock_t lock;
-
-	struct list_head free;
-	struct list_head clean;
-	struct list_head clean_pending;
-	struct list_head dirty;
-
-	/*
-	 * We know exactly how many cblocks will be needed,
-	 * so we can allocate them up front.
-	 */
-	dm_cblock_t cache_size, nr_cblocks_allocated;
-	struct wb_cache_entry *cblocks;
-	struct hash chash;
-};
-
-/*----------------------------------------------------------------------------*/
-
-/*
- * Low-level functions.
- */
-static unsigned next_power(unsigned n, unsigned min)
-{
-	return roundup_pow_of_two(max(n, min));
-}
-
-static struct policy *to_policy(struct dm_cache_policy *p)
-{
-	return container_of(p, struct policy, policy);
-}
-
-static struct list_head *list_pop(struct list_head *q)
-{
-	struct list_head *r = q->next;
-
-	list_del(r);
-
-	return r;
-}
-
-/*----------------------------------------------------------------------------*/
-
-/* Allocate/free various resources. */
-static int alloc_hash(struct hash *hash, unsigned elts)
-{
-	hash->nr_buckets = next_power(elts >> 4, 16);
-	hash->hash_bits = __ffs(hash->nr_buckets);
-	hash->table = vzalloc(sizeof(*hash->table) * hash->nr_buckets);
-
-	return hash->table ? 0 : -ENOMEM;
-}
-
-static void free_hash(struct hash *hash)
-{
-	vfree(hash->table);
-}
-
-static int alloc_cache_blocks_with_hash(struct policy *p, dm_cblock_t cache_size)
-{
-	int r = -ENOMEM;
-
-	p->cblocks = vzalloc(sizeof(*p->cblocks) * from_cblock(cache_size));
-	if (p->cblocks) {
-		unsigned u = from_cblock(cache_size);
-
-		while (u--)
-			list_add(&p->cblocks[u].list, &p->free);
-
-		p->nr_cblocks_allocated = 0;
-
-		/* Cache entries hash. */
-		r = alloc_hash(&p->chash, from_cblock(cache_size));
-		if (r)
-			vfree(p->cblocks);
-	}
-
-	return r;
-}
-
-static void free_cache_blocks_and_hash(struct policy *p)
-{
-	free_hash(&p->chash);
-	vfree(p->cblocks);
-}
-
-static struct wb_cache_entry *alloc_cache_entry(struct policy *p)
-{
-	struct wb_cache_entry *e;
-
-	BUG_ON(from_cblock(p->nr_cblocks_allocated) >= from_cblock(p->cache_size));
-
-	e = list_entry(list_pop(&p->free), struct wb_cache_entry, list);
-	p->nr_cblocks_allocated = to_cblock(from_cblock(p->nr_cblocks_allocated) + 1);
-
-	return e;
-}
-
-/*----------------------------------------------------------------------------*/
-
-/* Hash functions (lookup, insert, remove). */
-static struct wb_cache_entry *lookup_cache_entry(struct policy *p, dm_oblock_t oblock)
-{
-	struct hash *hash = &p->chash;
-	unsigned h = hash_64(from_oblock(oblock), hash->hash_bits);
-	struct wb_cache_entry *cur;
-	struct hlist_head *bucket = &hash->table[h];
-
-	hlist_for_each_entry(cur, bucket, hlist) {
-		if (cur->oblock == oblock) {
-			/* Move upfront bucket for faster access. */
-			hlist_del(&cur->hlist);
-			hlist_add_head(&cur->hlist, bucket);
-			return cur;
-		}
-	}
-
-	return NULL;
-}
-
-static void insert_cache_hash_entry(struct policy *p, struct wb_cache_entry *e)
-{
-	unsigned h = hash_64(from_oblock(e->oblock), p->chash.hash_bits);
-
-	hlist_add_head(&e->hlist, &p->chash.table[h]);
-}
-
-static void remove_cache_hash_entry(struct wb_cache_entry *e)
-{
-	hlist_del(&e->hlist);
-}
-
-/* Public interface (see dm-cache-policy.h */
-static int wb_map(struct dm_cache_policy *pe, dm_oblock_t oblock,
-		  bool can_block, bool can_migrate, bool discarded_oblock,
-		  struct bio *bio, struct policy_locker *locker,
-		  struct policy_result *result)
-{
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-	unsigned long flags;
-
-	result->op = POLICY_MISS;
-
-	if (can_block)
-		spin_lock_irqsave(&p->lock, flags);
-
-	else if (!spin_trylock_irqsave(&p->lock, flags))
-		return -EWOULDBLOCK;
-
-	e = lookup_cache_entry(p, oblock);
-	if (e) {
-		result->op = POLICY_HIT;
-		result->cblock = e->cblock;
-
-	}
-
-	spin_unlock_irqrestore(&p->lock, flags);
-
-	return 0;
-}
-
-static int wb_lookup(struct dm_cache_policy *pe, dm_oblock_t oblock, dm_cblock_t *cblock)
-{
-	int r;
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-	unsigned long flags;
-
-	if (!spin_trylock_irqsave(&p->lock, flags))
-		return -EWOULDBLOCK;
-
-	e = lookup_cache_entry(p, oblock);
-	if (e) {
-		*cblock = e->cblock;
-		r = 0;
-
-	} else
-		r = -ENOENT;
-
-	spin_unlock_irqrestore(&p->lock, flags);
-
-	return r;
-}
-
-static void __set_clear_dirty(struct dm_cache_policy *pe, dm_oblock_t oblock, bool set)
-{
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-
-	e = lookup_cache_entry(p, oblock);
-	BUG_ON(!e);
-
-	if (set) {
-		if (!e->dirty) {
-			e->dirty = true;
-			list_move(&e->list, &p->dirty);
-		}
-
-	} else {
-		if (e->dirty) {
-			e->pending = false;
-			e->dirty = false;
-			list_move(&e->list, &p->clean);
-		}
-	}
-}
-
-static void wb_set_dirty(struct dm_cache_policy *pe, dm_oblock_t oblock)
-{
-	struct policy *p = to_policy(pe);
-	unsigned long flags;
-
-	spin_lock_irqsave(&p->lock, flags);
-	__set_clear_dirty(pe, oblock, true);
-	spin_unlock_irqrestore(&p->lock, flags);
-}
-
-static void wb_clear_dirty(struct dm_cache_policy *pe, dm_oblock_t oblock)
-{
-	struct policy *p = to_policy(pe);
-	unsigned long flags;
-
-	spin_lock_irqsave(&p->lock, flags);
-	__set_clear_dirty(pe, oblock, false);
-	spin_unlock_irqrestore(&p->lock, flags);
-}
-
-static void add_cache_entry(struct policy *p, struct wb_cache_entry *e)
-{
-	insert_cache_hash_entry(p, e);
-	if (e->dirty)
-		list_add(&e->list, &p->dirty);
-	else
-		list_add(&e->list, &p->clean);
-}
-
-static int wb_load_mapping(struct dm_cache_policy *pe,
-			   dm_oblock_t oblock, dm_cblock_t cblock,
-			   uint32_t hint, bool hint_valid)
-{
-	int r;
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e = alloc_cache_entry(p);
-
-	if (e) {
-		e->cblock = cblock;
-		e->oblock = oblock;
-		e->dirty = false; /* blocks default to clean */
-		add_cache_entry(p, e);
-		r = 0;
-
-	} else
-		r = -ENOMEM;
-
-	return r;
-}
-
-static void wb_destroy(struct dm_cache_policy *pe)
-{
-	struct policy *p = to_policy(pe);
-
-	free_cache_blocks_and_hash(p);
-	kfree(p);
-}
-
-static struct wb_cache_entry *__wb_force_remove_mapping(struct policy *p, dm_oblock_t oblock)
-{
-	struct wb_cache_entry *r = lookup_cache_entry(p, oblock);
-
-	BUG_ON(!r);
-
-	remove_cache_hash_entry(r);
-	list_del(&r->list);
-
-	return r;
-}
-
-static void wb_remove_mapping(struct dm_cache_policy *pe, dm_oblock_t oblock)
-{
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-	unsigned long flags;
-
-	spin_lock_irqsave(&p->lock, flags);
-	e = __wb_force_remove_mapping(p, oblock);
-	list_add_tail(&e->list, &p->free);
-	BUG_ON(!from_cblock(p->nr_cblocks_allocated));
-	p->nr_cblocks_allocated = to_cblock(from_cblock(p->nr_cblocks_allocated) - 1);
-	spin_unlock_irqrestore(&p->lock, flags);
-}
-
-static void wb_force_mapping(struct dm_cache_policy *pe,
-				dm_oblock_t current_oblock, dm_oblock_t oblock)
-{
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-	unsigned long flags;
-
-	spin_lock_irqsave(&p->lock, flags);
-	e = __wb_force_remove_mapping(p, current_oblock);
-	e->oblock = oblock;
-	add_cache_entry(p, e);
-	spin_unlock_irqrestore(&p->lock, flags);
-}
-
-static struct wb_cache_entry *get_next_dirty_entry(struct policy *p)
-{
-	struct list_head *l;
-	struct wb_cache_entry *r;
-
-	if (list_empty(&p->dirty))
-		return NULL;
-
-	l = list_pop(&p->dirty);
-	r = container_of(l, struct wb_cache_entry, list);
-	list_add(l, &p->clean_pending);
-
-	return r;
-}
-
-static int wb_writeback_work(struct dm_cache_policy *pe,
-			     dm_oblock_t *oblock,
-			     dm_cblock_t *cblock,
-			     bool critical_only)
-{
-	int r = -ENOENT;
-	struct policy *p = to_policy(pe);
-	struct wb_cache_entry *e;
-	unsigned long flags;
-
-	spin_lock_irqsave(&p->lock, flags);
-
-	e = get_next_dirty_entry(p);
-	if (e) {
-		*oblock = e->oblock;
-		*cblock = e->cblock;
-		r = 0;
-	}
-
-	spin_unlock_irqrestore(&p->lock, flags);
-
-	return r;
-}
-
-static dm_cblock_t wb_residency(struct dm_cache_policy *pe)
-{
-	return to_policy(pe)->nr_cblocks_allocated;
-}
-
-/* Init the policy plugin interface function pointers. */
-static void init_policy_functions(struct policy *p)
-{
-	p->policy.destroy = wb_destroy;
-	p->policy.map = wb_map;
-	p->policy.lookup = wb_lookup;
-	p->policy.set_dirty = wb_set_dirty;
-	p->policy.clear_dirty = wb_clear_dirty;
-	p->policy.load_mapping = wb_load_mapping;
-	p->policy.get_hint = NULL;
-	p->policy.remove_mapping = wb_remove_mapping;
-	p->policy.writeback_work = wb_writeback_work;
-	p->policy.force_mapping = wb_force_mapping;
-	p->policy.residency = wb_residency;
-	p->policy.tick = NULL;
-}
-
-static struct dm_cache_policy *wb_create(dm_cblock_t cache_size,
-					 sector_t origin_size,
-					 sector_t cache_block_size)
-{
-	int r;
-	struct policy *p = kzalloc(sizeof(*p), GFP_KERNEL);
-
-	if (!p)
-		return NULL;
-
-	init_policy_functions(p);
-	INIT_LIST_HEAD(&p->free);
-	INIT_LIST_HEAD(&p->clean);
-	INIT_LIST_HEAD(&p->clean_pending);
-	INIT_LIST_HEAD(&p->dirty);
-
-	p->cache_size = cache_size;
-	spin_lock_init(&p->lock);
-
-	/* Allocate cache entry structs and add them to free list. */
-	r = alloc_cache_blocks_with_hash(p, cache_size);
-	if (!r)
-		return &p->policy;
-
-	kfree(p);
-
-	return NULL;
-}
-/*----------------------------------------------------------------------------*/
-
-static struct dm_cache_policy_type wb_policy_type = {
-	.name = "cleaner",
-	.version = {1, 0, 0},
-	.hint_size = 4,
-	.owner = THIS_MODULE,
-	.create = wb_create
-};
-
-static int __init wb_init(void)
-{
-	int r = dm_cache_policy_register(&wb_policy_type);
-
-	if (r < 0)
-		DMERR("register failed %d", r);
-	else
-		DMINFO("version %u.%u.%u loaded",
-		       wb_policy_type.version[0],
-		       wb_policy_type.version[1],
-		       wb_policy_type.version[2]);
-
-	return r;
-}
-
-static void __exit wb_exit(void)
-{
-	dm_cache_policy_unregister(&wb_policy_type);
-}
-
-module_init(wb_init);
-module_exit(wb_exit);
-
-MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("cleaner cache policy");
diff --git a/drivers/md/dm-cache-policy-internal.h b/drivers/md/dm-cache-policy-internal.h
index 808ee0e2b2c4..56f0a23f698c 100644
--- a/drivers/md/dm-cache-policy-internal.h
+++ b/drivers/md/dm-cache-policy-internal.h
@@ -12,70 +12,65 @@
 
 /*----------------------------------------------------------------*/
 
-/*
- * Little inline functions that simplify calling the policy methods.
- */
-static inline int policy_map(struct dm_cache_policy *p, dm_oblock_t oblock,
-			     bool can_block, bool can_migrate, bool discarded_oblock,
-			     struct bio *bio, struct policy_locker *locker,
-			     struct policy_result *result)
+static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
+				int data_dir, bool fast_copy, bool *background_queued)
 {
-	return p->map(p, oblock, can_block, can_migrate, discarded_oblock, bio, locker, result);
+	return p->lookup(p, oblock, cblock, data_dir, fast_copy, background_queued);
 }
 
-static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
+static inline int policy_lookup_with_work(struct dm_cache_policy *p,
+					  dm_oblock_t oblock, dm_cblock_t *cblock,
+					  int data_dir, bool fast_copy,
+					  struct policy_work **work)
 {
-	BUG_ON(!p->lookup);
-	return p->lookup(p, oblock, cblock);
-}
+	if (!p->lookup_with_work) {
+		*work = NULL;
+		return p->lookup(p, oblock, cblock, data_dir, fast_copy, NULL);
+	}
 
-static inline void policy_set_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
-{
-	if (p->set_dirty)
-		p->set_dirty(p, oblock);
+	return p->lookup_with_work(p, oblock, cblock, data_dir, fast_copy, work);
 }
 
-static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
+static inline int policy_get_background_work(struct dm_cache_policy *p,
+					     bool idle, struct policy_work **result)
 {
-	if (p->clear_dirty)
-		p->clear_dirty(p, oblock);
+	return p->get_background_work(p, idle, result);
 }
 
-static inline int policy_load_mapping(struct dm_cache_policy *p,
-				      dm_oblock_t oblock, dm_cblock_t cblock,
-				      uint32_t hint, bool hint_valid)
+static inline void policy_complete_background_work(struct dm_cache_policy *p,
+						   struct policy_work *work,
+						   bool success)
 {
-	return p->load_mapping(p, oblock, cblock, hint, hint_valid);
+	return p->complete_background_work(p, work, success);
 }
 
-static inline uint32_t policy_get_hint(struct dm_cache_policy *p,
-				       dm_cblock_t cblock)
+static inline void policy_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	return p->get_hint ? p->get_hint(p, cblock) : 0;
+	p->set_dirty(p, cblock);
 }
 
-static inline int policy_writeback_work(struct dm_cache_policy *p,
-					dm_oblock_t *oblock,
-					dm_cblock_t *cblock,
-					bool critical_only)
+static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	return p->writeback_work ? p->writeback_work(p, oblock, cblock, critical_only) : -ENOENT;
+	p->clear_dirty(p, cblock);
 }
 
-static inline void policy_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock)
+static inline int policy_load_mapping(struct dm_cache_policy *p,
+				      dm_oblock_t oblock, dm_cblock_t cblock,
+				      bool dirty, uint32_t hint, bool hint_valid)
 {
-	p->remove_mapping(p, oblock);
+	return p->load_mapping(p, oblock, cblock, dirty, hint, hint_valid);
 }
 
-static inline int policy_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)
+static inline int policy_invalidate_mapping(struct dm_cache_policy *p,
+					    dm_cblock_t cblock)
 {
-	return p->remove_cblock(p, cblock);
+	return p->invalidate_mapping(p, cblock);
 }
 
-static inline void policy_force_mapping(struct dm_cache_policy *p,
-					dm_oblock_t current_oblock, dm_oblock_t new_oblock)
+static inline uint32_t policy_get_hint(struct dm_cache_policy *p,
+				       dm_cblock_t cblock)
 {
-	return p->force_mapping(p, current_oblock, new_oblock);
+	return p->get_hint ? p->get_hint(p, cblock) : 0;
 }
 
 static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
@@ -107,6 +102,11 @@ static inline int policy_set_config_value(struct dm_cache_policy *p,
 	return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
 }
 
+static inline void policy_allow_migrations(struct dm_cache_policy *p, bool allow)
+{
+	return p->allow_migrations(p, allow);
+}
+
 /*----------------------------------------------------------------*/
 
 /*
diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c
index f19c6930a67c..e0c40aec5e96 100644
--- a/drivers/md/dm-cache-policy-smq.c
+++ b/drivers/md/dm-cache-policy-smq.c
@@ -4,8 +4,9 @@
  * This file is released under the GPL.
  */
 
-#include "dm-cache-policy.h"
+#include "dm-cache-background-tracker.h"
 #include "dm-cache-policy-internal.h"
+#include "dm-cache-policy.h"
 #include "dm.h"
 
 #include <linux/hash.h>
@@ -38,10 +39,11 @@ struct entry {
 	unsigned hash_next:28;
 	unsigned prev:28;
 	unsigned next:28;
-	unsigned level:7;
+	unsigned level:6;
 	bool dirty:1;
 	bool allocated:1;
 	bool sentinel:1;
+	bool pending_work:1;
 
 	dm_oblock_t oblock;
 };
@@ -279,14 +281,28 @@ static unsigned q_size(struct queue *q)
  */
 static void q_push(struct queue *q, struct entry *e)
 {
+	BUG_ON(e->pending_work);
+
 	if (!e->sentinel)
 		q->nr_elts++;
 
 	l_add_tail(q->es, q->qs + e->level, e);
 }
 
+static void q_push_front(struct queue *q, struct entry *e)
+{
+	BUG_ON(e->pending_work);
+
+	if (!e->sentinel)
+		q->nr_elts++;
+
+	l_add_head(q->es, q->qs + e->level, e);
+}
+
 static void q_push_before(struct queue *q, struct entry *old, struct entry *e)
 {
+	BUG_ON(e->pending_work);
+
 	if (!e->sentinel)
 		q->nr_elts++;
 
@@ -336,19 +352,6 @@ static struct entry *q_pop(struct queue *q)
 }
 
 /*
- * Pops an entry from a level that is not past a sentinel.
- */
-static struct entry *q_pop_old(struct queue *q, unsigned max_level)
-{
-	struct entry *e = q_peek(q, max_level, false);
-
-	if (e)
-		q_del(q, e);
-
-	return e;
-}
-
-/*
  * This function assumes there is a non-sentinel entry to pop.  It's only
  * used by redistribute, so we know this is true.  It also doesn't adjust
  * the q->nr_elts count.
@@ -446,45 +449,49 @@ static void q_redistribute(struct queue *q)
 				break;
 
 			e->level = level + 1u;
-			l_add_head(q->es, l_above, e);
+			l_add_tail(q->es, l_above, e);
 		}
 	}
 }
 
-static void q_requeue_before(struct queue *q, struct entry *dest, struct entry *e, unsigned extra_levels)
+static void q_requeue(struct queue *q, struct entry *e, unsigned extra_levels,
+		      struct entry *s1, struct entry *s2)
 {
 	struct entry *de;
-	unsigned new_level;
-
-	q_del(q, e);
+	unsigned sentinels_passed = 0;
+	unsigned new_level = min(q->nr_levels - 1u, e->level + extra_levels);
 
+	/* try and find an entry to swap with */
 	if (extra_levels && (e->level < q->nr_levels - 1u)) {
-		new_level = min(q->nr_levels - 1u, e->level + extra_levels);
-		for (de = l_head(q->es, q->qs + new_level); de; de = l_next(q->es, de)) {
-			if (de->sentinel)
-				continue;
+		for (de = l_head(q->es, q->qs + new_level); de && de->sentinel; de = l_next(q->es, de))
+			sentinels_passed++;
 
+		if (de) {
 			q_del(q, de);
 			de->level = e->level;
+			if (s1) {
+				switch (sentinels_passed) {
+				case 0:
+					q_push_before(q, s1, de);
+					break;
+
+				case 1:
+					q_push_before(q, s2, de);
+					break;
 
-			if (dest)
-				q_push_before(q, dest, de);
-			else
+				default:
+					q_push(q, de);
+				}
+			} else
 				q_push(q, de);
-			break;
 		}
-
-		e->level = new_level;
 	}
 
+	q_del(q, e);
+	e->level = new_level;
 	q_push(q, e);
 }
 
-static void q_requeue(struct queue *q, struct entry *e, unsigned extra_levels)
-{
-	q_requeue_before(q, NULL, e, extra_levels);
-}
-
 /*----------------------------------------------------------------*/
 
 #define FP_SHIFT 8
@@ -550,7 +557,7 @@ static enum performance stats_assess(struct stats *s)
 
 /*----------------------------------------------------------------*/
 
-struct hash_table {
+struct smq_hash_table {
 	struct entry_space *es;
 	unsigned long long hash_bits;
 	unsigned *buckets;
@@ -560,7 +567,7 @@ struct hash_table {
  * All cache entries are stored in a chained hash table.  To save space we
  * use indexing again, and only store indexes to the next entry.
  */
-static int h_init(struct hash_table *ht, struct entry_space *es, unsigned nr_entries)
+static int h_init(struct smq_hash_table *ht, struct entry_space *es, unsigned nr_entries)
 {
 	unsigned i, nr_buckets;
 
@@ -578,34 +585,34 @@ static int h_init(struct hash_table *ht, struct entry_space *es, unsigned nr_ent
 	return 0;
 }
 
-static void h_exit(struct hash_table *ht)
+static void h_exit(struct smq_hash_table *ht)
 {
 	vfree(ht->buckets);
 }
 
-static struct entry *h_head(struct hash_table *ht, unsigned bucket)
+static struct entry *h_head(struct smq_hash_table *ht, unsigned bucket)
 {
 	return to_entry(ht->es, ht->buckets[bucket]);
 }
 
-static struct entry *h_next(struct hash_table *ht, struct entry *e)
+static struct entry *h_next(struct smq_hash_table *ht, struct entry *e)
 {
 	return to_entry(ht->es, e->hash_next);
 }
 
-static void __h_insert(struct hash_table *ht, unsigned bucket, struct entry *e)
+static void __h_insert(struct smq_hash_table *ht, unsigned bucket, struct entry *e)
 {
 	e->hash_next = ht->buckets[bucket];
 	ht->buckets[bucket] = to_index(ht->es, e);
 }
 
-static void h_insert(struct hash_table *ht, struct entry *e)
+static void h_insert(struct smq_hash_table *ht, struct entry *e)
 {
 	unsigned h = hash_64(from_oblock(e->oblock), ht->hash_bits);
 	__h_insert(ht, h, e);
 }
 
-static struct entry *__h_lookup(struct hash_table *ht, unsigned h, dm_oblock_t oblock,
+static struct entry *__h_lookup(struct smq_hash_table *ht, unsigned h, dm_oblock_t oblock,
 				struct entry **prev)
 {
 	struct entry *e;
@@ -621,7 +628,7 @@ static struct entry *__h_lookup(struct hash_table *ht, unsigned h, dm_oblock_t o
 	return NULL;
 }
 
-static void __h_unlink(struct hash_table *ht, unsigned h,
+static void __h_unlink(struct smq_hash_table *ht, unsigned h,
 		       struct entry *e, struct entry *prev)
 {
 	if (prev)
@@ -633,7 +640,7 @@ static void __h_unlink(struct hash_table *ht, unsigned h,
 /*
  * Also moves each entry to the front of the bucket.
  */
-static struct entry *h_lookup(struct hash_table *ht, dm_oblock_t oblock)
+static struct entry *h_lookup(struct smq_hash_table *ht, dm_oblock_t oblock)
 {
 	struct entry *e, *prev;
 	unsigned h = hash_64(from_oblock(oblock), ht->hash_bits);
@@ -651,7 +658,7 @@ static struct entry *h_lookup(struct hash_table *ht, dm_oblock_t oblock)
 	return e;
 }
 
-static void h_remove(struct hash_table *ht, struct entry *e)
+static void h_remove(struct smq_hash_table *ht, struct entry *e)
 {
 	unsigned h = hash_64(from_oblock(e->oblock), ht->hash_bits);
 	struct entry *prev;
@@ -699,7 +706,10 @@ static void init_entry(struct entry *e)
 	e->next = INDEXER_NULL;
 	e->prev = INDEXER_NULL;
 	e->level = 0u;
+	e->dirty = true;	/* FIXME: audit */
 	e->allocated = true;
+	e->sentinel = false;
+	e->pending_work = false;
 }
 
 static struct entry *alloc_entry(struct entry_alloc *ea)
@@ -762,11 +772,11 @@ static struct entry *get_entry(struct entry_alloc *ea, unsigned index)
 #define NR_HOTSPOT_LEVELS 64u
 #define NR_CACHE_LEVELS 64u
 
-#define WRITEBACK_PERIOD (10 * HZ)
-#define DEMOTE_PERIOD (60 * HZ)
+#define WRITEBACK_PERIOD (10ul * HZ)
+#define DEMOTE_PERIOD (60ul * HZ)
 
 #define HOTSPOT_UPDATE_PERIOD (HZ)
-#define CACHE_UPDATE_PERIOD (10u * HZ)
+#define CACHE_UPDATE_PERIOD (60ul * HZ)
 
 struct smq_policy {
 	struct dm_cache_policy policy;
@@ -814,8 +824,8 @@ struct smq_policy {
 	 * The hash tables allows us to quickly find an entry by origin
 	 * block.
 	 */
-	struct hash_table table;
-	struct hash_table hotspot_table;
+	struct smq_hash_table table;
+	struct smq_hash_table hotspot_table;
 
 	bool current_writeback_sentinels;
 	unsigned long next_writeback_period;
@@ -828,6 +838,10 @@ struct smq_policy {
 
 	unsigned long next_hotspot_period;
 	unsigned long next_cache_period;
+
+	struct background_tracker *bg_work;
+
+	bool migrations_allowed;
 };
 
 /*----------------------------------------------------------------*/
@@ -876,15 +890,15 @@ static void __update_demote_sentinels(struct smq_policy *mq)
 static void update_sentinels(struct smq_policy *mq)
 {
 	if (time_after(jiffies, mq->next_writeback_period)) {
-		__update_writeback_sentinels(mq);
 		mq->next_writeback_period = jiffies + WRITEBACK_PERIOD;
 		mq->current_writeback_sentinels = !mq->current_writeback_sentinels;
+		__update_writeback_sentinels(mq);
 	}
 
 	if (time_after(jiffies, mq->next_demote_period)) {
-		__update_demote_sentinels(mq);
 		mq->next_demote_period = jiffies + DEMOTE_PERIOD;
 		mq->current_demote_sentinels = !mq->current_demote_sentinels;
+		__update_demote_sentinels(mq);
 	}
 }
 
@@ -920,55 +934,40 @@ static void sentinels_init(struct smq_policy *mq)
 
 /*----------------------------------------------------------------*/
 
-/*
- * These methods tie together the dirty queue, clean queue and hash table.
- */
-static void push_new(struct smq_policy *mq, struct entry *e)
+static void del_queue(struct smq_policy *mq, struct entry *e)
 {
-	struct queue *q = e->dirty ? &mq->dirty : &mq->clean;
-	h_insert(&mq->table, e);
-	q_push(q, e);
+	q_del(e->dirty ? &mq->dirty : &mq->clean, e);
 }
 
-static void push(struct smq_policy *mq, struct entry *e)
+static void push_queue(struct smq_policy *mq, struct entry *e)
 {
-	struct entry *sentinel;
-
-	h_insert(&mq->table, e);
-
-	/*
-	 * Punch this into the queue just in front of the sentinel, to
-	 * ensure it's cleaned straight away.
-	 */
-	if (e->dirty) {
-		sentinel = writeback_sentinel(mq, e->level);
-		q_push_before(&mq->dirty, sentinel, e);
-	} else {
-		sentinel = demote_sentinel(mq, e->level);
-		q_push_before(&mq->clean, sentinel, e);
-	}
+	if (e->dirty)
+		q_push(&mq->dirty, e);
+	else
+		q_push(&mq->clean, e);
 }
 
-/*
- * Removes an entry from cache.  Removes from the hash table.
- */
-static void __del(struct smq_policy *mq, struct queue *q, struct entry *e)
+// !h, !q, a -> h, q, a
+static void push(struct smq_policy *mq, struct entry *e)
 {
-	q_del(q, e);
-	h_remove(&mq->table, e);
+	h_insert(&mq->table, e);
+	if (!e->pending_work)
+		push_queue(mq, e);
 }
 
-static void del(struct smq_policy *mq, struct entry *e)
+static void push_queue_front(struct smq_policy *mq, struct entry *e)
 {
-	__del(mq, e->dirty ? &mq->dirty : &mq->clean, e);
+	if (e->dirty)
+		q_push_front(&mq->dirty, e);
+	else
+		q_push_front(&mq->clean, e);
 }
 
-static struct entry *pop_old(struct smq_policy *mq, struct queue *q, unsigned max_level)
+static void push_front(struct smq_policy *mq, struct entry *e)
 {
-	struct entry *e = q_pop_old(q, max_level);
-	if (e)
-		h_remove(&mq->table, e);
-	return e;
+	h_insert(&mq->table, e);
+	if (!e->pending_work)
+		push_queue_front(mq, e);
 }
 
 static dm_cblock_t infer_cblock(struct smq_policy *mq, struct entry *e)
@@ -978,16 +977,21 @@ static dm_cblock_t infer_cblock(struct smq_policy *mq, struct entry *e)
 
 static void requeue(struct smq_policy *mq, struct entry *e)
 {
-	struct entry *sentinel;
+	/*
+	 * Pending work has temporarily been taken out of the queues.
+	 */
+	if (e->pending_work)
+		return;
 
 	if (!test_and_set_bit(from_cblock(infer_cblock(mq, e)), mq->cache_hit_bits)) {
-		if (e->dirty) {
-			sentinel = writeback_sentinel(mq, e->level);
-			q_requeue_before(&mq->dirty, sentinel, e, 1u);
-		} else {
-			sentinel = demote_sentinel(mq, e->level);
-			q_requeue_before(&mq->clean, sentinel, e, 1u);
+		if (!e->dirty) {
+			q_requeue(&mq->clean, e, 1u, NULL, NULL);
+			return;
 		}
+
+		q_requeue(&mq->dirty, e, 1u,
+			  get_sentinel(&mq->writeback_sentinel_alloc, e->level, !mq->current_writeback_sentinels),
+			  get_sentinel(&mq->writeback_sentinel_alloc, e->level, mq->current_writeback_sentinels));
 	}
 }
 
@@ -1026,6 +1030,8 @@ static void update_promote_levels(struct smq_policy *mq)
 	unsigned threshold_level = allocator_empty(&mq->cache_alloc) ?
 		default_promote_level(mq) : (NR_HOTSPOT_LEVELS / 2u);
 
+	threshold_level = max(threshold_level, NR_HOTSPOT_LEVELS);
+
 	/*
 	 * If the hotspot queue is performing badly then we have little
 	 * confidence that we know which blocks to promote.  So we cut down
@@ -1045,7 +1051,7 @@ static void update_promote_levels(struct smq_policy *mq)
 	}
 
 	mq->read_promote_level = NR_HOTSPOT_LEVELS - threshold_level;
-	mq->write_promote_level = (NR_HOTSPOT_LEVELS - threshold_level) + 2u;
+	mq->write_promote_level = (NR_HOTSPOT_LEVELS - threshold_level);
 }
 
 /*
@@ -1095,34 +1101,142 @@ static void end_cache_period(struct smq_policy *mq)
 	}
 }
 
-static int demote_cblock(struct smq_policy *mq,
-			 struct policy_locker *locker,
-			 dm_oblock_t *oblock)
+/*----------------------------------------------------------------*/
+
+/*
+ * Targets are given as a percentage.
+ */
+#define CLEAN_TARGET 25u
+#define FREE_TARGET 25u
+
+static unsigned percent_to_target(struct smq_policy *mq, unsigned p)
 {
-	struct entry *demoted = q_peek(&mq->clean, mq->clean.nr_levels, false);
-	if (!demoted)
-		/*
-		 * We could get a block from mq->dirty, but that
-		 * would add extra latency to the triggering bio as it
-		 * waits for the writeback.  Better to not promote this
-		 * time and hope there's a clean block next time this block
-		 * is hit.
-		 */
-		return -ENOSPC;
+	return from_cblock(mq->cache_size) * p / 100u;
+}
+
+static bool clean_target_met(struct smq_policy *mq, bool idle)
+{
+	/*
+	 * Cache entries may not be populated.  So we cannot rely on the
+	 * size of the clean queue.
+	 */
+	unsigned nr_clean = from_cblock(mq->cache_size) - q_size(&mq->dirty);
 
-	if (locker->fn(locker, demoted->oblock))
+	if (idle)
 		/*
-		 * We couldn't lock this block.
+		 * We'd like to clean everything.
 		 */
-		return -EBUSY;
+		return q_size(&mq->dirty) == 0u;
+	else
+		return (nr_clean + btracker_nr_writebacks_queued(mq->bg_work)) >=
+		       percent_to_target(mq, CLEAN_TARGET);
+}
 
-	del(mq, demoted);
-	*oblock = demoted->oblock;
-	free_entry(&mq->cache_alloc, demoted);
+static bool free_target_met(struct smq_policy *mq, bool idle)
+{
+	unsigned nr_free = from_cblock(mq->cache_size) -
+			   mq->cache_alloc.nr_allocated;
 
-	return 0;
+	if (idle)
+		return (nr_free + btracker_nr_demotions_queued(mq->bg_work)) >=
+		       percent_to_target(mq, FREE_TARGET);
+	else
+		return true;
 }
 
+/*----------------------------------------------------------------*/
+
+static void mark_pending(struct smq_policy *mq, struct entry *e)
+{
+	BUG_ON(e->sentinel);
+	BUG_ON(!e->allocated);
+	BUG_ON(e->pending_work);
+	e->pending_work = true;
+}
+
+static void clear_pending(struct smq_policy *mq, struct entry *e)
+{
+	BUG_ON(!e->pending_work);
+	e->pending_work = false;
+}
+
+static void queue_writeback(struct smq_policy *mq)
+{
+	int r;
+	struct policy_work work;
+	struct entry *e;
+
+	e = q_peek(&mq->dirty, mq->dirty.nr_levels, !mq->migrations_allowed);
+	if (e) {
+		mark_pending(mq, e);
+		q_del(&mq->dirty, e);
+
+		work.op = POLICY_WRITEBACK;
+		work.oblock = e->oblock;
+		work.cblock = infer_cblock(mq, e);
+
+		r = btracker_queue(mq->bg_work, &work, NULL);
+		WARN_ON_ONCE(r); // FIXME: finish, I think we have to get rid of this race.
+	}
+}
+
+static void queue_demotion(struct smq_policy *mq)
+{
+	struct policy_work work;
+	struct entry *e;
+
+	if (unlikely(WARN_ON_ONCE(!mq->migrations_allowed)))
+		return;
+
+	e = q_peek(&mq->clean, mq->clean.nr_levels, true);
+	if (!e) {
+		if (!clean_target_met(mq, false))
+			queue_writeback(mq);
+		return;
+	}
+
+	mark_pending(mq, e);
+	q_del(&mq->clean, e);
+
+	work.op = POLICY_DEMOTE;
+	work.oblock = e->oblock;
+	work.cblock = infer_cblock(mq, e);
+	btracker_queue(mq->bg_work, &work, NULL);
+}
+
+static void queue_promotion(struct smq_policy *mq, dm_oblock_t oblock,
+			    struct policy_work **workp)
+{
+	struct entry *e;
+	struct policy_work work;
+
+	if (!mq->migrations_allowed)
+		return;
+
+	if (allocator_empty(&mq->cache_alloc)) {
+		if (!free_target_met(mq, false))
+			queue_demotion(mq);
+		return;
+	}
+
+	if (btracker_promotion_already_present(mq->bg_work, oblock))
+		return;
+
+	/*
+	 * We allocate the entry now to reserve the cblock.  If the
+	 * background work is aborted we must remember to free it.
+	 */
+	e = alloc_entry(&mq->cache_alloc);
+	BUG_ON(!e);
+	e->pending_work = true;
+	work.op = POLICY_PROMOTE;
+	work.oblock = oblock;
+	work.cblock = infer_cblock(mq, e);
+	btracker_queue(mq->bg_work, &work, workp);
+}
+
+/*----------------------------------------------------------------*/
+
 enum promote_result {
 	PROMOTE_NOT,
 	PROMOTE_TEMPORARY,
@@ -1137,49 +1251,18 @@ static enum promote_result maybe_promote(bool promote)
 	return promote ? PROMOTE_PERMANENT : PROMOTE_NOT;
 }
 
-static enum promote_result should_promote(struct smq_policy *mq, struct entry *hs_e, struct bio *bio,
-					  bool fast_promote)
+static enum promote_result should_promote(struct smq_policy *mq, struct entry *hs_e,
+					  int data_dir, bool fast_promote)
 {
-	if (bio_data_dir(bio) == WRITE) {
+	if (data_dir == WRITE) {
 		if (!allocator_empty(&mq->cache_alloc) && fast_promote)
 			return PROMOTE_TEMPORARY;
 
-		else
-			return maybe_promote(hs_e->level >= mq->write_promote_level);
+		return maybe_promote(hs_e->level >= mq->write_promote_level);
 	} else
 		return maybe_promote(hs_e->level >= mq->read_promote_level);
 }
 
-static void insert_in_cache(struct smq_policy *mq, dm_oblock_t oblock,
-			    struct policy_locker *locker,
-			    struct policy_result *result, enum promote_result pr)
-{
-	int r;
-	struct entry *e;
-
-	if (allocator_empty(&mq->cache_alloc)) {
-		result->op = POLICY_REPLACE;
-		r = demote_cblock(mq, locker, &result->old_oblock);
-		if (r) {
-			result->op = POLICY_MISS;
-			return;
-		}
-
-	} else
-		result->op = POLICY_NEW;
-
-	e = alloc_entry(&mq->cache_alloc);
-	BUG_ON(!e);
-	e->oblock = oblock;
-
-	if (pr == PROMOTE_TEMPORARY)
-		push(mq, e);
-	else
-		push_new(mq, e);
-
-	result->cblock = infer_cblock(mq, e);
-}
-
 static dm_oblock_t to_hblock(struct smq_policy *mq, dm_oblock_t b)
 {
 	sector_t r = from_oblock(b);
@@ -1187,7 +1270,7 @@ static dm_oblock_t to_hblock(struct smq_policy *mq, dm_oblock_t b)
 	return to_oblock(r);
 }
 
-static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b, struct bio *bio)
+static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b)
 {
 	unsigned hi;
 	dm_oblock_t hb = to_hblock(mq, b);
@@ -1199,7 +1282,8 @@ static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b,
 		hi = get_index(&mq->hotspot_alloc, e);
 		q_requeue(&mq->hotspot, e,
 			  test_and_set_bit(hi, mq->hotspot_hit_bits) ?
-			  0u : mq->hotspot_level_jump);
+			  0u : mq->hotspot_level_jump,
+			  NULL, NULL);
 
 	} else {
 		stats_miss(&mq->hotspot_stats);
@@ -1225,47 +1309,6 @@ static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b,
 	return e;
 }
 
-/*
- * Looks the oblock up in the hash table, then decides whether to put in
- * pre_cache, or cache etc.
- */
-static int map(struct smq_policy *mq, struct bio *bio, dm_oblock_t oblock,
-	       bool can_migrate, bool fast_promote,
-	       struct policy_locker *locker, struct policy_result *result)
-{
-	struct entry *e, *hs_e;
-	enum promote_result pr;
-
-	hs_e = update_hotspot_queue(mq, oblock, bio);
-
-	e = h_lookup(&mq->table, oblock);
-	if (e) {
-		stats_level_accessed(&mq->cache_stats, e->level);
-
-		requeue(mq, e);
-		result->op = POLICY_HIT;
-		result->cblock = infer_cblock(mq, e);
-
-	} else {
-		stats_miss(&mq->cache_stats);
-
-		pr = should_promote(mq, hs_e, bio, fast_promote);
-		if (pr == PROMOTE_NOT)
-			result->op = POLICY_MISS;
-
-		else {
-			if (!can_migrate) {
-				result->op = POLICY_MISS;
-				return -EWOULDBLOCK;
-			}
-
-			insert_in_cache(mq, oblock, locker, result, pr);
-		}
-	}
-
-	return 0;
-}
-
 /*----------------------------------------------------------------*/
 
 /*
@@ -1282,6 +1325,7 @@ static void smq_destroy(struct dm_cache_policy *p)
 {
 	struct smq_policy *mq = to_smq_policy(p);
 
+	btracker_destroy(mq->bg_work);
 	h_exit(&mq->hotspot_table);
 	h_exit(&mq->table);
 	free_bitset(mq->hotspot_hit_bits);
@@ -1290,234 +1334,247 @@ static void smq_destroy(struct dm_cache_policy *p)
 	kfree(mq);
 }
 
-static int smq_map(struct dm_cache_policy *p, dm_oblock_t oblock,
-		   bool can_block, bool can_migrate, bool fast_promote,
-		   struct bio *bio, struct policy_locker *locker,
-		   struct policy_result *result)
-{
-	int r;
-	unsigned long flags;
-	struct smq_policy *mq = to_smq_policy(p);
-
-	result->op = POLICY_MISS;
-
-	spin_lock_irqsave(&mq->lock, flags);
-	r = map(mq, bio, oblock, can_migrate, fast_promote, locker, result);
-	spin_unlock_irqrestore(&mq->lock, flags);
-
-	return r;
-}
+/*----------------------------------------------------------------*/
 
-static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock)
+static int __lookup(struct smq_policy *mq, dm_oblock_t oblock, dm_cblock_t *cblock,
+		    int data_dir, bool fast_copy,
+		    struct policy_work **work, bool *background_work)
 {
-	int r;
-	unsigned long flags;
-	struct smq_policy *mq = to_smq_policy(p);
-	struct entry *e;
+	struct entry *e, *hs_e;
+	enum promote_result pr;
+
+	*background_work = false;
 
-	spin_lock_irqsave(&mq->lock, flags);
 	e = h_lookup(&mq->table, oblock);
 	if (e) {
+		stats_level_accessed(&mq->cache_stats, e->level);
+
+		requeue(mq, e);
 		*cblock = infer_cblock(mq, e);
-		r = 0;
-	} else
-		r = -ENOENT;
-	spin_unlock_irqrestore(&mq->lock, flags);
+		return 0;
 
-	return r;
-}
+	} else {
+		stats_miss(&mq->cache_stats);
 
-static void __smq_set_clear_dirty(struct smq_policy *mq, dm_oblock_t oblock, bool set)
-{
-	struct entry *e;
+		/*
+		 * The hotspot queue only gets updated with misses.
+		 */
+		hs_e = update_hotspot_queue(mq, oblock);
 
-	e = h_lookup(&mq->table, oblock);
-	BUG_ON(!e);
+		pr = should_promote(mq, hs_e, data_dir, fast_copy);
+		if (pr != PROMOTE_NOT) {
+			queue_promotion(mq, oblock, work);
+			*background_work = true;
+		}
 
-	del(mq, e);
-	e->dirty = set;
-	push(mq, e);
+		return -ENOENT;
+	}
 }
 
-static void smq_set_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
+static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
+		      int data_dir, bool fast_copy,
+		      bool *background_work)
 {
+	int r;
 	unsigned long flags;
 	struct smq_policy *mq = to_smq_policy(p);
 
 	spin_lock_irqsave(&mq->lock, flags);
-	__smq_set_clear_dirty(mq, oblock, true);
+	r = __lookup(mq, oblock, cblock,
+		     data_dir, fast_copy,
+		     NULL, background_work);
 	spin_unlock_irqrestore(&mq->lock, flags);
+
+	return r;
 }
 
-static void smq_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
+static int smq_lookup_with_work(struct dm_cache_policy *p,
+				dm_oblock_t oblock, dm_cblock_t *cblock,
+				int data_dir, bool fast_copy,
+				struct policy_work **work)
 {
-	struct smq_policy *mq = to_smq_policy(p);
+	int r;
+	bool background_queued;
 	unsigned long flags;
+	struct smq_policy *mq = to_smq_policy(p);
 
 	spin_lock_irqsave(&mq->lock, flags);
-	__smq_set_clear_dirty(mq, oblock, false);
+	r = __lookup(mq, oblock, cblock, data_dir, fast_copy, work, &background_queued);
 	spin_unlock_irqrestore(&mq->lock, flags);
-}
 
-static unsigned random_level(dm_cblock_t cblock)
-{
-	return hash_32(from_cblock(cblock), 9) & (NR_CACHE_LEVELS - 1);
+	return r;
 }
 
-static int smq_load_mapping(struct dm_cache_policy *p,
-			    dm_oblock_t oblock, dm_cblock_t cblock,
-			    uint32_t hint, bool hint_valid)
+static int smq_get_background_work(struct dm_cache_policy *p, bool idle,
+				   struct policy_work **result)
 {
+	int r;
+	unsigned long flags;
 	struct smq_policy *mq = to_smq_policy(p);
-	struct entry *e;
 
-	e = alloc_particular_entry(&mq->cache_alloc, from_cblock(cblock));
-	e->oblock = oblock;
-	e->dirty = false;	/* this gets corrected in a minute */
-	e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : random_level(cblock);
-	push(mq, e);
-
-	return 0;
-}
+	spin_lock_irqsave(&mq->lock, flags);
+	r = btracker_issue(mq->bg_work, result);
+	if (r == -ENODATA) {
+		/* find some writeback work to do */
+		if (mq->migrations_allowed && !free_target_met(mq, idle))
+			queue_demotion(mq);
 
-static uint32_t smq_get_hint(struct dm_cache_policy *p, dm_cblock_t cblock)
-{
-	struct smq_policy *mq = to_smq_policy(p);
-	struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
+		else if (!clean_target_met(mq, idle))
+			queue_writeback(mq);
 
-	if (!e->allocated)
-		return 0;
+		r = btracker_issue(mq->bg_work, result);
+	}
+	spin_unlock_irqrestore(&mq->lock, flags);
 
-	return e->level;
+	return r;
 }
 
-static void __remove_mapping(struct smq_policy *mq, dm_oblock_t oblock)
-{
-	struct entry *e;
+/*
+ * We need to clear any pending work flags that have been set, and in the
+ * case of promotion free the entry for the destination cblock.
+ */
+static void __complete_background_work(struct smq_policy *mq,
+				       struct policy_work *work,
+				       bool success)
+{
+	struct entry *e = get_entry(&mq->cache_alloc,
+				    from_cblock(work->cblock));
+
+	switch (work->op) {
+	case POLICY_PROMOTE:
+		// !h, !q, a
+		clear_pending(mq, e);
+		if (success) {
+			e->oblock = work->oblock;
+			push(mq, e);
+			// h, q, a
+		} else {
+			free_entry(&mq->cache_alloc, e);
+			// !h, !q, !a
+		}
+		break;
 
-	e = h_lookup(&mq->table, oblock);
-	BUG_ON(!e);
+	case POLICY_DEMOTE:
+		// h, !q, a
+		if (success) {
+			h_remove(&mq->table, e);
+			free_entry(&mq->cache_alloc, e);
+			// !h, !q, !a
+		} else {
+			clear_pending(mq, e);
+			push_queue(mq, e);
+			// h, q, a
+		}
+		break;
 
-	del(mq, e);
-	free_entry(&mq->cache_alloc, e);
+	case POLICY_WRITEBACK:
+		// h, !q, a
+		clear_pending(mq, e);
+		push_queue(mq, e);
+		// h, q, a
+		break;
+	}
+
+	btracker_complete(mq->bg_work, work);
 }
 
-static void smq_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock)
+static void smq_complete_background_work(struct dm_cache_policy *p,
+					 struct policy_work *work,
+					 bool success)
 {
-	struct smq_policy *mq = to_smq_policy(p);
 	unsigned long flags;
+	struct smq_policy *mq = to_smq_policy(p);
 
 	spin_lock_irqsave(&mq->lock, flags);
-	__remove_mapping(mq, oblock);
+	__complete_background_work(mq, work, success);
 	spin_unlock_irqrestore(&mq->lock, flags);
 }
 
-static int __remove_cblock(struct smq_policy *mq, dm_cblock_t cblock)
+// in_hash(oblock) -> in_hash(oblock)
+static void __smq_set_clear_dirty(struct smq_policy *mq, dm_cblock_t cblock, bool set)
 {
 	struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
 
-	if (!e || !e->allocated)
-		return -ENODATA;
-
-	del(mq, e);
-	free_entry(&mq->cache_alloc, e);
-
-	return 0;
+	if (e->pending_work)
+		e->dirty = set;
+	else {
+		del_queue(mq, e);
+		e->dirty = set;
+		push_queue(mq, e);
+	}
 }
 
-static int smq_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock)
+static void smq_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	int r;
 	unsigned long flags;
 	struct smq_policy *mq = to_smq_policy(p);
 
 	spin_lock_irqsave(&mq->lock, flags);
-	r = __remove_cblock(mq, cblock);
+	__smq_set_clear_dirty(mq, cblock, true);
 	spin_unlock_irqrestore(&mq->lock, flags);
-
-	return r;
 }
 
-
-#define CLEAN_TARGET_CRITICAL 5u /* percent */
-
-static bool clean_target_met(struct smq_policy *mq, bool critical)
+static void smq_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	if (critical) {
-		/*
-		 * Cache entries may not be populated.  So we're cannot rely on the
-		 * size of the clean queue.
-		 */
-		unsigned nr_clean = from_cblock(mq->cache_size) - q_size(&mq->dirty);
-		unsigned target = from_cblock(mq->cache_size) * CLEAN_TARGET_CRITICAL / 100u;
+	struct smq_policy *mq = to_smq_policy(p);
+	unsigned long flags;
 
-		return nr_clean >= target;
-	} else
-		return !q_size(&mq->dirty);
+	spin_lock_irqsave(&mq->lock, flags);
+	__smq_set_clear_dirty(mq, cblock, false);
+	spin_unlock_irqrestore(&mq->lock, flags);
 }
 
-static int __smq_writeback_work(struct smq_policy *mq, dm_oblock_t *oblock,
-				dm_cblock_t *cblock, bool critical_only)
+static unsigned random_level(dm_cblock_t cblock)
 {
-	struct entry *e = NULL;
-	bool target_met = clean_target_met(mq, critical_only);
-
-	if (critical_only)
-		/*
-		 * Always try and keep the bottom level clean.
-		 */
-		e = pop_old(mq, &mq->dirty, target_met ? 1u : mq->dirty.nr_levels);
+	return hash_32(from_cblock(cblock), 9) & (NR_CACHE_LEVELS - 1);
+}
 
-	else
-		e = pop_old(mq, &mq->dirty, mq->dirty.nr_levels);
+static int smq_load_mapping(struct dm_cache_policy *p,
+			    dm_oblock_t oblock, dm_cblock_t cblock,
+			    bool dirty, uint32_t hint, bool hint_valid)
+{
+	struct smq_policy *mq = to_smq_policy(p);
+	struct entry *e;
 
-	if (!e)
-		return -ENODATA;
+	e = alloc_particular_entry(&mq->cache_alloc, from_cblock(cblock));
+	e->oblock = oblock;
+	e->dirty = dirty;
+	e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : random_level(cblock);
+	e->pending_work = false;
 
-	*oblock = e->oblock;
-	*cblock = infer_cblock(mq, e);
-	e->dirty = false;
-	push_new(mq, e);
+	/*
+	 * When we load mappings we push ahead of both sentinels in order to
+	 * allow demotions and cleaning to occur immediately.
+	 */
+	push_front(mq, e);
 
 	return 0;
 }
 
-static int smq_writeback_work(struct dm_cache_policy *p, dm_oblock_t *oblock,
-			      dm_cblock_t *cblock, bool critical_only)
+static int smq_invalidate_mapping(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	int r;
-	unsigned long flags;
 	struct smq_policy *mq = to_smq_policy(p);
+	struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
 
-	spin_lock_irqsave(&mq->lock, flags);
-	r = __smq_writeback_work(mq, oblock, cblock, critical_only);
-	spin_unlock_irqrestore(&mq->lock, flags);
-
-	return r;
-}
-
-static void __force_mapping(struct smq_policy *mq,
-			    dm_oblock_t current_oblock, dm_oblock_t new_oblock)
-{
-	struct entry *e = h_lookup(&mq->table, current_oblock);
+	if (!e->allocated)
+		return -ENODATA;
 
-	if (e) {
-		del(mq, e);
-		e->oblock = new_oblock;
-		e->dirty = true;
-		push(mq, e);
-	}
+	// FIXME: what if this block has pending background work?
+	del_queue(mq, e);
+	h_remove(&mq->table, e);
+	free_entry(&mq->cache_alloc, e);
+	return 0;
 }
 
-static void smq_force_mapping(struct dm_cache_policy *p,
-			      dm_oblock_t current_oblock, dm_oblock_t new_oblock)
+static uint32_t smq_get_hint(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
-	unsigned long flags;
 	struct smq_policy *mq = to_smq_policy(p);
+	struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
 
-	spin_lock_irqsave(&mq->lock, flags);
-	__force_mapping(mq, current_oblock, new_oblock);
-	spin_unlock_irqrestore(&mq->lock, flags);
+	if (!e->allocated)
+		return 0;
+
+	return e->level;
 }
 
 static dm_cblock_t smq_residency(struct dm_cache_policy *p)
@@ -1546,6 +1603,12 @@ static void smq_tick(struct dm_cache_policy *p, bool can_block)
 	spin_unlock_irqrestore(&mq->lock, flags);
 }
 
+static void smq_allow_migrations(struct dm_cache_policy *p, bool allow)
+{
+	struct smq_policy *mq = to_smq_policy(p);
+	mq->migrations_allowed = allow;
+}
+
 /*
  * smq has no config values, but the old mq policy did.  To avoid breaking
  * software we continue to accept these configurables for the mq policy,
@@ -1590,18 +1653,18 @@ static int mq_emit_config_values(struct dm_cache_policy *p, char *result,
 static void init_policy_functions(struct smq_policy *mq, bool mimic_mq)
 {
 	mq->policy.destroy = smq_destroy;
-	mq->policy.map = smq_map;
 	mq->policy.lookup = smq_lookup;
+	mq->policy.lookup_with_work = smq_lookup_with_work;
+	mq->policy.get_background_work = smq_get_background_work;
+	mq->policy.complete_background_work = smq_complete_background_work;
 	mq->policy.set_dirty = smq_set_dirty;
 	mq->policy.clear_dirty = smq_clear_dirty;
 	mq->policy.load_mapping = smq_load_mapping;
+	mq->policy.invalidate_mapping = smq_invalidate_mapping;
 	mq->policy.get_hint = smq_get_hint;
-	mq->policy.remove_mapping = smq_remove_mapping;
-	mq->policy.remove_cblock = smq_remove_cblock;
-	mq->policy.writeback_work = smq_writeback_work;
-	mq->policy.force_mapping = smq_force_mapping;
 	mq->policy.residency = smq_residency;
 	mq->policy.tick = smq_tick;
+	mq->policy.allow_migrations = smq_allow_migrations;
 
 	if (mimic_mq) {
 		mq->policy.set_config_value = mq_set_config_value;
@@ -1633,7 +1696,8 @@ static void calc_hotspot_params(sector_t origin_size,
 static struct dm_cache_policy *__smq_create(dm_cblock_t cache_size,
 					    sector_t origin_size,
 					    sector_t cache_block_size,
-					    bool mimic_mq)
+					    bool mimic_mq,
+					    bool migrations_allowed)
 {
 	unsigned i;
 	unsigned nr_sentinels_per_queue = 2u * NR_CACHE_LEVELS;
@@ -1658,11 +1722,11 @@ static struct dm_cache_policy *__smq_create(dm_cblock_t cache_size,
 	}
 
 	init_allocator(&mq->writeback_sentinel_alloc, &mq->es, 0, nr_sentinels_per_queue);
-        for (i = 0; i < nr_sentinels_per_queue; i++)
+	for (i = 0; i < nr_sentinels_per_queue; i++)
 		get_entry(&mq->writeback_sentinel_alloc, i)->sentinel = true;
 
 	init_allocator(&mq->demote_sentinel_alloc, &mq->es, nr_sentinels_per_queue, total_sentinels);
-        for (i = 0; i < nr_sentinels_per_queue; i++)
+	for (i = 0; i < nr_sentinels_per_queue; i++)
 		get_entry(&mq->demote_sentinel_alloc, i)->sentinel = true;
 
 	init_allocator(&mq->hotspot_alloc, &mq->es, total_sentinels,
@@ -1715,8 +1779,16 @@ static struct dm_cache_policy *__smq_create(dm_cblock_t cache_size,
 	mq->next_hotspot_period = jiffies;
 	mq->next_cache_period = jiffies;
 
+	mq->bg_work = btracker_create(10240); /* FIXME: hard coded value */
+	if (!mq->bg_work)
+		goto bad_btracker;
+
+	mq->migrations_allowed = migrations_allowed;
+
 	return &mq->policy;
 
+bad_btracker:
+	h_exit(&mq->hotspot_table);
 bad_alloc_hotspot_table:
 	h_exit(&mq->table);
 bad_alloc_table:
@@ -1735,21 +1807,28 @@ static struct dm_cache_policy *smq_create(dm_cblock_t cache_size,
 					  sector_t origin_size,
 					  sector_t cache_block_size)
 {
-	return __smq_create(cache_size, origin_size, cache_block_size, false);
+	return __smq_create(cache_size, origin_size, cache_block_size, false, true);
 }
 
 static struct dm_cache_policy *mq_create(dm_cblock_t cache_size,
 					 sector_t origin_size,
 					 sector_t cache_block_size)
 {
-	return __smq_create(cache_size, origin_size, cache_block_size, true);
+	return __smq_create(cache_size, origin_size, cache_block_size, true, true);
+}
+
+static struct dm_cache_policy *cleaner_create(dm_cblock_t cache_size,
+					      sector_t origin_size,
+					      sector_t cache_block_size)
+{
+	return __smq_create(cache_size, origin_size, cache_block_size, false, false);
 }
 
 /*----------------------------------------------------------------*/
 
 static struct dm_cache_policy_type smq_policy_type = {
 	.name = "smq",
-	.version = {1, 5, 0},
+	.version = {2, 0, 0},
 	.hint_size = 4,
 	.owner = THIS_MODULE,
 	.create = smq_create
@@ -1757,15 +1836,23 @@ static struct dm_cache_policy_type smq_policy_type = {
 
 static struct dm_cache_policy_type mq_policy_type = {
 	.name = "mq",
-	.version = {1, 5, 0},
+	.version = {2, 0, 0},
 	.hint_size = 4,
 	.owner = THIS_MODULE,
 	.create = mq_create,
 };
 
+static struct dm_cache_policy_type cleaner_policy_type = {
+	.name = "cleaner",
+	.version = {2, 0, 0},
+	.hint_size = 4,
+	.owner = THIS_MODULE,
+	.create = cleaner_create,
+};
+
 static struct dm_cache_policy_type default_policy_type = {
 	.name = "default",
-	.version = {1, 5, 0},
+	.version = {2, 0, 0},
 	.hint_size = 4,
 	.owner = THIS_MODULE,
 	.create = smq_create,
@@ -1785,23 +1872,36 @@ static int __init smq_init(void)
 	r = dm_cache_policy_register(&mq_policy_type);
 	if (r) {
 		DMERR("register failed (as mq) %d", r);
-		dm_cache_policy_unregister(&smq_policy_type);
-		return -ENOMEM;
+		goto out_mq;
+	}
+
+	r = dm_cache_policy_register(&cleaner_policy_type);
+	if (r) {
+		DMERR("register failed (as cleaner) %d", r);
+		goto out_cleaner;
 	}
 
 	r = dm_cache_policy_register(&default_policy_type);
 	if (r) {
 		DMERR("register failed (as default) %d", r);
-		dm_cache_policy_unregister(&mq_policy_type);
-		dm_cache_policy_unregister(&smq_policy_type);
-		return -ENOMEM;
+		goto out_default;
 	}
 
 	return 0;
+
+out_default:
+	dm_cache_policy_unregister(&cleaner_policy_type);
+out_cleaner:
+	dm_cache_policy_unregister(&mq_policy_type);
+out_mq:
+	dm_cache_policy_unregister(&smq_policy_type);
+
+	return -ENOMEM;
 }
 
 static void __exit smq_exit(void)
 {
+	dm_cache_policy_unregister(&cleaner_policy_type);
 	dm_cache_policy_unregister(&smq_policy_type);
 	dm_cache_policy_unregister(&mq_policy_type);
 	dm_cache_policy_unregister(&default_policy_type);
@@ -1816,3 +1916,4 @@ MODULE_DESCRIPTION("smq cache policy");
 
 MODULE_ALIAS("dm-cache-default");
 MODULE_ALIAS("dm-cache-mq");
+MODULE_ALIAS("dm-cache-cleaner");
diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h
index aa10b1493f34..c05fc3436cef 100644
--- a/drivers/md/dm-cache-policy.h
+++ b/drivers/md/dm-cache-policy.h
@@ -13,183 +13,100 @@
 
 /*----------------------------------------------------------------*/
 
-/* FIXME: make it clear which methods are optional.  Get debug policy to
- * double check this at start.
- */
-
 /*
  * The cache policy makes the important decisions about which blocks get to
  * live on the faster cache device.
- *
- * When the core target has to remap a bio it calls the 'map' method of the
- * policy.  This returns an instruction telling the core target what to do.
- *
- * POLICY_HIT:
- *   That block is in the cache.  Remap to the cache and carry on.
- *
- * POLICY_MISS:
- *   This block is on the origin device.  Remap and carry on.
- *
- * POLICY_NEW:
- *   This block is currently on the origin device, but the policy wants to
- *   move it.  The core should:
- *
- *   - hold any further io to this origin block
- *   - copy the origin to the given cache block
- *   - release all the held blocks
- *   - remap the original block to the cache
- *
- * POLICY_REPLACE:
- *   This block is currently on the origin device.  The policy wants to
- *   move it to the cache, with the added complication that the destination
- *   cache block needs a writeback first.  The core should:
- *
- *   - hold any further io to this origin block
- *   - hold any further io to the origin block that's being written back
- *   - writeback
- *   - copy new block to cache
- *   - release held blocks
- *   - remap bio to cache and reissue.
- *
- * Should the core run into trouble while processing a POLICY_NEW or
- * POLICY_REPLACE instruction it will roll back the policies mapping using
- * remove_mapping() or force_mapping().  These methods must not fail.  This
- * approach avoids having transactional semantics in the policy (ie, the
- * core informing the policy when a migration is complete), and hence makes
- * it easier to write new policies.
- *
- * In general policy methods should never block, except in the case of the
- * map function when can_migrate is set.  So be careful to implement using
- * bounded, preallocated memory.
  */
 enum policy_operation {
-	POLICY_HIT,
-	POLICY_MISS,
-	POLICY_NEW,
-	POLICY_REPLACE
-};
-
-/*
- * When issuing a POLICY_REPLACE the policy needs to make a callback to
- * lock the block being demoted.  This doesn't need to occur during a
- * writeback operation since the block remains in the cache.
- */
-struct policy_locker;
-typedef int (*policy_lock_fn)(struct policy_locker *l, dm_oblock_t oblock);
-
-struct policy_locker {
-	policy_lock_fn fn;
+	POLICY_PROMOTE,
+	POLICY_DEMOTE,
+	POLICY_WRITEBACK
 };
 
 /*
  * This is the instruction passed back to the core target.
  */
-struct policy_result {
+struct policy_work {
 	enum policy_operation op;
-	dm_oblock_t old_oblock;	/* POLICY_REPLACE */
-	dm_cblock_t cblock;	/* POLICY_HIT, POLICY_NEW, POLICY_REPLACE */
+	dm_oblock_t oblock;
+	dm_cblock_t cblock;
 };
 
 /*
- * The cache policy object.  Just a bunch of methods.  It is envisaged that
- * this structure will be embedded in a bigger, policy specific structure
- * (ie. use container_of()).
+ * The cache policy object.  It is envisaged that this structure will be
+ * embedded in a bigger, policy specific structure (ie. use container_of()).
  */
 struct dm_cache_policy {
-
-	/*
-	 * FIXME: make it clear which methods are optional, and which may
-	 * block.
-	 */
-
 	/*
 	 * Destroys this object.
 	 */
 	void (*destroy)(struct dm_cache_policy *p);
 
 	/*
-	 * See large comment above.
-	 *
-	 * oblock      - the origin block we're interested in.
-	 *
-	 * can_block - indicates whether the current thread is allowed to
-	 *             block.  -EWOULDBLOCK returned if it can't and would.
-	 *
-	 * can_migrate - gives permission for POLICY_NEW or POLICY_REPLACE
-	 *               instructions.  If denied and the policy would have
-	 *               returned one of these instructions it should
-	 *               return -EWOULDBLOCK.
+	 * Find the location of a block.
 	 *
-	 * discarded_oblock - indicates whether the whole origin block is
-	 *               in a discarded state (FIXME: better to tell the
-	 *               policy about this sooner, so it can recycle that
-	 *               cache block if it wants.)
-	 * bio         - the bio that triggered this call.
-	 * result      - gets filled in with the instruction.
+	 * Must not block.
 	 *
-	 * May only return 0, or -EWOULDBLOCK (if !can_migrate)
+	 * Returns 0 if in cache (cblock will be set), -ENOENT if not, < 0 for
+	 * other errors (-EWOULDBLOCK would be typical).  data_dir should be
+	 * READ or WRITE. fast_copy should be set if migrating this block would
+	 * be 'cheap' somehow (eg, discarded data). background_queued will be set
+	 * if a migration has just been queued.
 	 */
-	int (*map)(struct dm_cache_policy *p, dm_oblock_t oblock,
-		   bool can_block, bool can_migrate, bool discarded_oblock,
-		   struct bio *bio, struct policy_locker *locker,
-		   struct policy_result *result);
+	int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
+		      int data_dir, bool fast_copy, bool *background_queued);
 
 	/*
-	 * Sometimes we want to see if a block is in the cache, without
-	 * triggering any update of stats.  (ie. it's not a real hit).
-	 *
-	 * Must not block.
+	 * Sometimes the core target can optimise a migration, eg, the
+	 * block may be discarded, or the bio may cover an entire block.
+	 * In order to optimise it needs the migration immediately though
+	 * so it knows to do something different with the bio.
 	 *
-	 * Returns 0 if in cache, -ENOENT if not, < 0 for other errors
-	 * (-EWOULDBLOCK would be typical).
+	 * This method is optional (policy-internal will fallback to using
+	 * lookup).
 	 */
-	int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock);
-
-	void (*set_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
-	void (*clear_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
+	int (*lookup_with_work)(struct dm_cache_policy *p,
+				dm_oblock_t oblock, dm_cblock_t *cblock,
+				int data_dir, bool fast_copy,
+				struct policy_work **work);
 
 	/*
-	 * Called when a cache target is first created.  Used to load a
-	 * mapping from the metadata device into the policy.
+	 * Retrieves background work.  Returns -ENODATA when there's no
+	 * background work.
 	 */
-	int (*load_mapping)(struct dm_cache_policy *p, dm_oblock_t oblock,
-			    dm_cblock_t cblock, uint32_t hint, bool hint_valid);
+	int (*get_background_work)(struct dm_cache_policy *p, bool idle,
+			           struct policy_work **result);
 
 	/*
-	 * Gets the hint for a given cblock.  Called in a single threaded
-	 * context.  So no locking required.
+	 * You must pass in the same work pointer that you were given, not
+	 * a copy.
 	 */
-	uint32_t (*get_hint)(struct dm_cache_policy *p, dm_cblock_t cblock);
+	void (*complete_background_work)(struct dm_cache_policy *p,
+					 struct policy_work *work,
+					 bool success);
+
+	void (*set_dirty)(struct dm_cache_policy *p, dm_cblock_t cblock);
+	void (*clear_dirty)(struct dm_cache_policy *p, dm_cblock_t cblock);
 
 	/*
-	 * Override functions used on the error paths of the core target.
-	 * They must succeed.
+	 * Called when a cache target is first created.  Used to load a
+	 * mapping from the metadata device into the policy.
 	 */
-	void (*remove_mapping)(struct dm_cache_policy *p, dm_oblock_t oblock);
-	void (*force_mapping)(struct dm_cache_policy *p, dm_oblock_t current_oblock,
-			      dm_oblock_t new_oblock);
+	int (*load_mapping)(struct dm_cache_policy *p, dm_oblock_t oblock,
+			    dm_cblock_t cblock, bool dirty,
+			    uint32_t hint, bool hint_valid);
 
 	/*
-	 * This is called via the invalidate_cblocks message.  It is
-	 * possible the particular cblock has already been removed due to a
-	 * write io in passthrough mode.  In which case this should return
-	 * -ENODATA.
+	 * Drops the mapping, irrespective of whether it's clean or dirty.
+	 * Returns -ENODATA if cblock is not mapped.
 	 */
-	int (*remove_cblock)(struct dm_cache_policy *p, dm_cblock_t cblock);
+	int (*invalidate_mapping)(struct dm_cache_policy *p, dm_cblock_t cblock);
 
 	/*
-	 * Provide a dirty block to be written back by the core target.  If
-	 * critical_only is set then the policy should only provide work if
-	 * it urgently needs it.
-	 *
-	 * Returns:
-	 *
-	 * 0 and @cblock,@oblock: block to write back provided
-	 *
-	 * -ENODATA: no dirty blocks available
+	 * Gets the hint for a given cblock.  Called in a single threaded
+	 * context.  So no locking required.
 	 */
-	int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock,
-			      bool critical_only);
+	uint32_t (*get_hint)(struct dm_cache_policy *p, dm_cblock_t cblock);
 
 	/*
 	 * How full is the cache?
@@ -202,6 +119,8 @@ struct dm_cache_policy {
 	 * queue merging has occurred).  To stop the policy being fooled by
 	 * these, the core target sends regular tick() calls to the policy.
 	 * The policy should only count an entry as hit once per tick.
+	 *
+	 * This method is optional.
 	 */
 	void (*tick)(struct dm_cache_policy *p, bool can_block);
 
@@ -213,6 +132,8 @@ struct dm_cache_policy {
 	int (*set_config_value)(struct dm_cache_policy *p,
 				const char *key, const char *value);
 
+	void (*allow_migrations)(struct dm_cache_policy *p, bool allow);
+
 	/*
 	 * Book keeping ptr for the policy register, not for general use.
 	 */
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 975922c8f231..1db375f50a13 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -5,7 +5,7 @@
  */
 
 #include "dm.h"
-#include "dm-bio-prison.h"
+#include "dm-bio-prison-v2.h"
 #include "dm-bio-record.h"
 #include "dm-cache-metadata.h"
 
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/mempool.h>
 #include <linux/module.h>
+#include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -25,7 +26,18 @@ DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle,
 
 /*----------------------------------------------------------------*/
 
-#define IOT_RESOLUTION 4
+/*
+ * Glossary:
+ *
+ * oblock: index of an origin block
+ * cblock: index of a cache block
+ * promotion: movement of a block from origin to cache
+ * demotion: movement of a block from cache to origin
+ * migration: movement of a block between the origin and cache device,
+ *	      either direction
+ */
+
+/*----------------------------------------------------------------*/
 
 struct io_tracker {
 	spinlock_t lock;
@@ -99,19 +111,178 @@ static void iot_io_end(struct io_tracker *iot, sector_t len)
 /*----------------------------------------------------------------*/
 
 /*
- * Glossary:
- *
- * oblock: index of an origin block
- * cblock: index of a cache block
- * promotion: movement of a block from origin to cache
- * demotion: movement of a block from cache to origin
- * migration: movement of a block between the origin and cache device,
- *	      either direction
+ * Represents a chunk of future work.  'input' allows continuations to pass
+ * values between themselves, typically error values.
  */
+struct continuation {
+	struct work_struct ws;
+	int input;
+};
+
+static inline void init_continuation(struct continuation *k,
+				     void (*fn)(struct work_struct *))
+{
+	INIT_WORK(&k->ws, fn);
+	k->input = 0;
+}
+
+static inline void queue_continuation(struct workqueue_struct *wq,
+				      struct continuation *k)
+{
+	queue_work(wq, &k->ws);
+}
 
 /*----------------------------------------------------------------*/
 
 /*
+ * The batcher collects together pieces of work that need a particular
+ * operation to occur before they can proceed (typically a commit).
+ */
+struct batcher {
+	/*
+	 * The operation that everyone is waiting for.
+	 */
+	int (*commit_op)(void *context);
+	void *commit_context;
+
+	/*
+	 * This is how bios should be issued once the commit op is complete
+	 * (accounted_request).
+	 */
+	void (*issue_op)(struct bio *bio, void *context);
+	void *issue_context;
+
+	/*
+	 * Queued work gets put on here after commit.
+	 */
+	struct workqueue_struct *wq;
+
+	spinlock_t lock;
+	struct list_head work_items;
+	struct bio_list bios;
+	struct work_struct commit_work;
+
+	bool commit_scheduled;
+};
+
+static void __commit(struct work_struct *_ws)
+{
+	struct batcher *b = container_of(_ws, struct batcher, commit_work);
+
+	int r;
+	unsigned long flags;
+	struct list_head work_items;
+	struct work_struct *ws, *tmp;
+	struct continuation *k;
+	struct bio *bio;
+	struct bio_list bios;
+
+	INIT_LIST_HEAD(&work_items);
+	bio_list_init(&bios);
+
+	/*
+	 * We have to grab these before the commit_op to avoid a race
+	 * condition.
+	 */
+	spin_lock_irqsave(&b->lock, flags);
+	list_splice_init(&b->work_items, &work_items);
+	bio_list_merge(&bios, &b->bios);
+	bio_list_init(&b->bios);
+	b->commit_scheduled = false;
+	spin_unlock_irqrestore(&b->lock, flags);
+
+	r = b->commit_op(b->commit_context);
+
+	list_for_each_entry_safe(ws, tmp, &work_items, entry) {
+		k = container_of(ws, struct continuation, ws);
+		k->input = r;
+		INIT_LIST_HEAD(&ws->entry); /* to avoid a WARN_ON */
+		queue_work(b->wq, ws);
+	}
+
+	while ((bio = bio_list_pop(&bios))) {
+		if (r) {
+			bio->bi_error = r;
+			bio_endio(bio);
+		} else
+			b->issue_op(bio, b->issue_context);
+	}
+}
+
+static void batcher_init(struct batcher *b,
+			 int (*commit_op)(void *),
+			 void *commit_context,
+			 void (*issue_op)(struct bio *bio, void *),
+			 void *issue_context,
+			 struct workqueue_struct *wq)
+{
+	b->commit_op = commit_op;
+	b->commit_context = commit_context;
+	b->issue_op = issue_op;
+	b->issue_context = issue_context;
+	b->wq = wq;
+
+	spin_lock_init(&b->lock);
+	INIT_LIST_HEAD(&b->work_items);
+	bio_list_init(&b->bios);
+	INIT_WORK(&b->commit_work, __commit);
+	b->commit_scheduled = false;
+}
+
+static void async_commit(struct batcher *b)
+{
+	queue_work(b->wq, &b->commit_work);
+}
+
+static void continue_after_commit(struct batcher *b, struct continuation *k)
+{
+	unsigned long flags;
+	bool commit_scheduled;
+
+	spin_lock_irqsave(&b->lock, flags);
+	commit_scheduled = b->commit_scheduled;
+	list_add_tail(&k->ws.entry, &b->work_items);
+	spin_unlock_irqrestore(&b->lock, flags);
+
+	if (commit_scheduled)
+		async_commit(b);
+}
+
+/*
+ * Bios are errored if commit failed.
+ */
+static void issue_after_commit(struct batcher *b, struct bio *bio)
+{
+       unsigned long flags;
+       bool commit_scheduled;
+
+       spin_lock_irqsave(&b->lock, flags);
+       commit_scheduled = b->commit_scheduled;
+       bio_list_add(&b->bios, bio);
+       spin_unlock_irqrestore(&b->lock, flags);
+
+       if (commit_scheduled)
+	       async_commit(b);
+}
+
+/*
+ * Call this if some urgent work is waiting for the commit to complete.
+ */
+static void schedule_commit(struct batcher *b)
+{
+	bool immediate;
+	unsigned long flags;
+
+	spin_lock_irqsave(&b->lock, flags);
+	immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios);
+	b->commit_scheduled = true;
+	spin_unlock_irqrestore(&b->lock, flags);
+
+	if (immediate)
+		async_commit(b);
+}
+
+/*
  * There are a couple of places where we let a bio run, but want to do some
  * work before calling its endio function.  We do this by temporarily
  * changing the endio fn.
@@ -189,31 +360,13 @@ struct cache_stats {
 	atomic_t write_miss;
 	atomic_t demotion;
 	atomic_t promotion;
+	atomic_t writeback;
 	atomic_t copies_avoided;
 	atomic_t cache_cell_clash;
 	atomic_t commit_count;
 	atomic_t discard_count;
 };
 
-/*
- * Defines a range of cblocks, begin to (end - 1) are in the range.  end is
- * the one-past-the-end value.
- */
-struct cblock_range {
-	dm_cblock_t begin;
-	dm_cblock_t end;
-};
-
-struct invalidation_request {
-	struct list_head list;
-	struct cblock_range *cblocks;
-
-	atomic_t complete;
-	int err;
-
-	wait_queue_head_t result_wait;
-};
-
 struct cache {
 	struct dm_target *ti;
 	struct dm_target_callbacks callbacks;
@@ -255,11 +408,7 @@ struct cache {
 	spinlock_t lock;
 	struct list_head deferred_cells;
 	struct bio_list deferred_bios;
-	struct bio_list deferred_flush_bios;
 	struct bio_list deferred_writethrough_bios;
-	struct list_head quiesced_migrations;
-	struct list_head completed_migrations;
-	struct list_head need_commit_migrations;
 	sector_t migration_threshold;
 	wait_queue_head_t migration_wait;
 	atomic_t nr_allocated_migrations;
@@ -270,9 +419,7 @@ struct cache {
 	 */
 	atomic_t nr_io_migrations;
 
-	wait_queue_head_t quiescing_wait;
-	atomic_t quiescing;
-	atomic_t quiescing_ack;
+	struct rw_semaphore quiesce_lock;
 
 	/*
 	 * cache_size entries, dirty if set
@@ -296,13 +443,11 @@ struct cache {
 
 	struct dm_kcopyd_client *copier;
 	struct workqueue_struct *wq;
-	struct work_struct worker;
-
+	struct work_struct deferred_bio_worker;
+	struct work_struct deferred_writethrough_worker;
+	struct work_struct migration_worker;
 	struct delayed_work waker;
-	unsigned long last_commit_jiffies;
-
-	struct dm_bio_prison *prison;
-	struct dm_deferred_set *all_io_ds;
+	struct dm_bio_prison_v2 *prison;
 
 	mempool_t *migration_pool;
 
@@ -330,12 +475,17 @@ struct cache {
 	struct list_head invalidation_requests;
 
 	struct io_tracker origin_tracker;
+
+	struct work_struct commit_ws;
+	struct batcher committer;
+
+	struct rw_semaphore background_work_lock;
 };
 
 struct per_bio_data {
 	bool tick:1;
 	unsigned req_nr:2;
-	struct dm_deferred_entry *all_io_entry;
+	struct dm_bio_prison_cell_v2 *cell;
 	struct dm_hook_info hook_info;
 	sector_t len;
 
@@ -350,55 +500,64 @@ struct per_bio_data {
 };
 
 struct dm_cache_migration {
-	struct list_head list;
+	struct continuation k;
 	struct cache *cache;
 
-	unsigned long start_jiffies;
-	dm_oblock_t old_oblock;
-	dm_oblock_t new_oblock;
-	dm_cblock_t cblock;
-
-	bool err:1;
-	bool discard:1;
-	bool writeback:1;
-	bool demote:1;
-	bool promote:1;
-	bool requeue_holder:1;
-	bool invalidate:1;
+	struct policy_work *op;
+	struct bio *overwrite_bio;
+	struct dm_bio_prison_cell_v2 *cell;
 
-	struct dm_bio_prison_cell *old_ocell;
-	struct dm_bio_prison_cell *new_ocell;
+	dm_cblock_t invalidate_cblock;
+	dm_oblock_t invalidate_oblock;
 };
 
-/*
- * Processing a bio in the worker thread may require these memory
- * allocations.  We prealloc to avoid deadlocks (the same worker thread
- * frees them back to the mempool).
- */
-struct prealloc {
-	struct dm_cache_migration *mg;
-	struct dm_bio_prison_cell *cell1;
-	struct dm_bio_prison_cell *cell2;
-};
+/*----------------------------------------------------------------*/
+
+static bool writethrough_mode(struct cache_features *f)
+{
+	return f->io_mode == CM_IO_WRITETHROUGH;
+}
 
-static enum cache_metadata_mode get_cache_mode(struct cache *cache);
+static bool writeback_mode(struct cache_features *f)
+{
+	return f->io_mode == CM_IO_WRITEBACK;
+}
 
-static void wake_worker(struct cache *cache)
+static inline bool passthrough_mode(struct cache_features *f)
 {
-	queue_work(cache->wq, &cache->worker);
+	return unlikely(f->io_mode == CM_IO_PASSTHROUGH);
 }
 
 /*----------------------------------------------------------------*/
 
-static struct dm_bio_prison_cell *alloc_prison_cell(struct cache *cache)
+static void wake_deferred_bio_worker(struct cache *cache)
 {
-	/* FIXME: change to use a local slab. */
-	return dm_bio_prison_alloc_cell(cache->prison, GFP_NOWAIT);
+	queue_work(cache->wq, &cache->deferred_bio_worker);
 }
 
-static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell *cell)
+static void wake_deferred_writethrough_worker(struct cache *cache)
 {
-	dm_bio_prison_free_cell(cache->prison, cell);
+	queue_work(cache->wq, &cache->deferred_writethrough_worker);
+}
+
+static void wake_migration_worker(struct cache *cache)
+{
+	if (passthrough_mode(&cache->features))
+		return;
+
+	queue_work(cache->wq, &cache->migration_worker);
+}
+
+/*----------------------------------------------------------------*/
+
+static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache)
+{
+	return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOWAIT);
+}
+
+static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell)
+{
+	dm_bio_prison_free_cell_v2(cache->prison, cell);
 }
 
 static struct dm_cache_migration *alloc_migration(struct cache *cache)
@@ -424,146 +583,127 @@ static void free_migration(struct dm_cache_migration *mg)
 	mempool_free(mg, cache->migration_pool);
 }
 
-static int prealloc_data_structs(struct cache *cache, struct prealloc *p)
-{
-	if (!p->mg) {
-		p->mg = alloc_migration(cache);
-		if (!p->mg)
-			return -ENOMEM;
-	}
-
-	if (!p->cell1) {
-		p->cell1 = alloc_prison_cell(cache);
-		if (!p->cell1)
-			return -ENOMEM;
-	}
-
-	if (!p->cell2) {
-		p->cell2 = alloc_prison_cell(cache);
-		if (!p->cell2)
-			return -ENOMEM;
-	}
-
-	return 0;
-}
+/*----------------------------------------------------------------*/
 
-static void prealloc_free_structs(struct cache *cache, struct prealloc *p)
+static inline dm_oblock_t oblock_succ(dm_oblock_t b)
 {
-	if (p->cell2)
-		free_prison_cell(cache, p->cell2);
-
-	if (p->cell1)
-		free_prison_cell(cache, p->cell1);
-
-	if (p->mg)
-		free_migration(p->mg);
+	return to_oblock(from_oblock(b) + 1ull);
 }
 
-static struct dm_cache_migration *prealloc_get_migration(struct prealloc *p)
+static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key)
 {
-	struct dm_cache_migration *mg = p->mg;
-
-	BUG_ON(!mg);
-	p->mg = NULL;
-
-	return mg;
+	key->virtual = 0;
+	key->dev = 0;
+	key->block_begin = from_oblock(begin);
+	key->block_end = from_oblock(end);
 }
 
 /*
- * You must have a cell within the prealloc struct to return.  If not this
- * function will BUG() rather than returning NULL.
+ * We have two lock levels.  Level 0, which is used to prevent WRITEs, and
+ * level 1 which prevents *both* READs and WRITEs.
  */
-static struct dm_bio_prison_cell *prealloc_get_cell(struct prealloc *p)
+#define WRITE_LOCK_LEVEL 0
+#define READ_WRITE_LOCK_LEVEL 1
+
+static unsigned lock_level(struct bio *bio)
 {
-	struct dm_bio_prison_cell *r = NULL;
+	return bio_data_dir(bio) == WRITE ?
+		WRITE_LOCK_LEVEL :
+		READ_WRITE_LOCK_LEVEL;
+}
 
-	if (p->cell1) {
-		r = p->cell1;
-		p->cell1 = NULL;
+/*----------------------------------------------------------------
+ * Per bio data
+ *--------------------------------------------------------------*/
 
-	} else if (p->cell2) {
-		r = p->cell2;
-		p->cell2 = NULL;
-	} else
-		BUG();
+/*
+ * If using writeback, leave out struct per_bio_data's writethrough fields.
+ */
+#define PB_DATA_SIZE_WB (offsetof(struct per_bio_data, cache))
+#define PB_DATA_SIZE_WT (sizeof(struct per_bio_data))
 
-	return r;
+static size_t get_per_bio_data_size(struct cache *cache)
+{
+	return writethrough_mode(&cache->features) ? PB_DATA_SIZE_WT : PB_DATA_SIZE_WB;
 }
 
-/*
- * You can't have more than two cells in a prealloc struct.  BUG() will be
- * called if you try and overfill.
- */
-static void prealloc_put_cell(struct prealloc *p, struct dm_bio_prison_cell *cell)
+static struct per_bio_data *get_per_bio_data(struct bio *bio, size_t data_size)
 {
-	if (!p->cell2)
-		p->cell2 = cell;
+	struct per_bio_data *pb = dm_per_bio_data(bio, data_size);
+	BUG_ON(!pb);
+	return pb;
+}
 
-	else if (!p->cell1)
-		p->cell1 = cell;
+static struct per_bio_data *init_per_bio_data(struct bio *bio, size_t data_size)
+{
+	struct per_bio_data *pb = get_per_bio_data(bio, data_size);
 
-	else
-		BUG();
+	pb->tick = false;
+	pb->req_nr = dm_bio_get_target_bio_nr(bio);
+	pb->cell = NULL;
+	pb->len = 0;
+
+	return pb;
 }
 
 /*----------------------------------------------------------------*/
 
-static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key *key)
+static void defer_bio(struct cache *cache, struct bio *bio)
 {
-	key->virtual = 0;
-	key->dev = 0;
-	key->block_begin = from_oblock(begin);
-	key->block_end = from_oblock(end);
-}
+	unsigned long flags;
 
-/*
- * The caller hands in a preallocated cell, and a free function for it.
- * The cell will be freed if there's an error, or if it wasn't used because
- * a cell with that key already exists.
- */
-typedef void (*cell_free_fn)(void *context, struct dm_bio_prison_cell *cell);
+	spin_lock_irqsave(&cache->lock, flags);
+	bio_list_add(&cache->deferred_bios, bio);
+	spin_unlock_irqrestore(&cache->lock, flags);
 
-static int bio_detain_range(struct cache *cache, dm_oblock_t oblock_begin, dm_oblock_t oblock_end,
-			    struct bio *bio, struct dm_bio_prison_cell *cell_prealloc,
-			    cell_free_fn free_fn, void *free_context,
-			    struct dm_bio_prison_cell **cell_result)
+	wake_deferred_bio_worker(cache);
+}
+
+static void defer_bios(struct cache *cache, struct bio_list *bios)
 {
-	int r;
-	struct dm_cell_key key;
+	unsigned long flags;
 
-	build_key(oblock_begin, oblock_end, &key);
-	r = dm_bio_detain(cache->prison, &key, bio, cell_prealloc, cell_result);
-	if (r)
-		free_fn(free_context, cell_prealloc);
+	spin_lock_irqsave(&cache->lock, flags);
+	bio_list_merge(&cache->deferred_bios, bios);
+	bio_list_init(bios);
+	spin_unlock_irqrestore(&cache->lock, flags);
 
-	return r;
+	wake_deferred_bio_worker(cache);
 }
 
-static int bio_detain(struct cache *cache, dm_oblock_t oblock,
-		      struct bio *bio, struct dm_bio_prison_cell *cell_prealloc,
-		      cell_free_fn free_fn, void *free_context,
-		      struct dm_bio_prison_cell **cell_result)
+/*----------------------------------------------------------------*/
+
+static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio)
 {
+	bool r;
+	size_t pb_size;
+	struct per_bio_data *pb;
+	struct dm_cell_key_v2 key;
 	dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL);
-	return bio_detain_range(cache, oblock, end, bio,
-				cell_prealloc, free_fn, free_context, cell_result);
-}
+	struct dm_bio_prison_cell_v2 *cell_prealloc, *cell;
 
-static int get_cell(struct cache *cache,
-		    dm_oblock_t oblock,
-		    struct prealloc *structs,
-		    struct dm_bio_prison_cell **cell_result)
-{
-	int r;
-	struct dm_cell_key key;
-	struct dm_bio_prison_cell *cell_prealloc;
+	cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */
+	if (!cell_prealloc) {
+		defer_bio(cache, bio);
+		return false;
+	}
 
-	cell_prealloc = prealloc_get_cell(structs);
+	build_key(oblock, end, &key);
+	r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell);
+	if (!r) {
+		/*
+		 * Failed to get the lock.
+		 */
+		free_prison_cell(cache, cell_prealloc);
+		return r;
+	}
 
-	build_key(oblock, to_oblock(from_oblock(oblock) + 1ULL), &key);
-	r = dm_get_cell(cache->prison, &key, cell_prealloc, cell_result);
-	if (r)
-		prealloc_put_cell(structs, cell_prealloc);
+	if (cell != cell_prealloc)
+		free_prison_cell(cache, cell_prealloc);
+
+	pb_size = get_per_bio_data_size(cache);
+	pb = get_per_bio_data(bio, pb_size);
+	pb->cell = cell;
 
 	return r;
 }
@@ -575,21 +715,33 @@ static bool is_dirty(struct cache *cache, dm_cblock_t b)
 	return test_bit(from_cblock(b), cache->dirty_bitset);
 }
 
-static void set_dirty(struct cache *cache, dm_oblock_t oblock, dm_cblock_t cblock)
+static void set_dirty(struct cache *cache, dm_cblock_t cblock)
 {
 	if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) {
 		atomic_inc(&cache->nr_dirty);
-		policy_set_dirty(cache->policy, oblock);
+		policy_set_dirty(cache->policy, cblock);
 	}
 }
 
-static void clear_dirty(struct cache *cache, dm_oblock_t oblock, dm_cblock_t cblock)
+/*
+ * These two are called when setting after migrations to force the policy
+ * and dirty bitset to be in sync.
+ */
+static void force_set_dirty(struct cache *cache, dm_cblock_t cblock)
+{
+	if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset))
+		atomic_inc(&cache->nr_dirty);
+	policy_set_dirty(cache->policy, cblock);
+}
+
+static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock)
 {
 	if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) {
-		policy_clear_dirty(cache->policy, oblock);
 		if (atomic_dec_return(&cache->nr_dirty) == 0)
 			dm_table_event(cache->ti->table);
 	}
+
+	policy_clear_dirty(cache->policy, cblock);
 }
 
 /*----------------------------------------------------------------*/
@@ -628,11 +780,6 @@ static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock)
 				   oblocks_per_dblock(cache)));
 }
 
-static dm_oblock_t dblock_to_oblock(struct cache *cache, dm_dblock_t dblock)
-{
-	return to_oblock(from_dblock(dblock) * oblocks_per_dblock(cache));
-}
-
 static void set_discard(struct cache *cache, dm_dblock_t b)
 {
 	unsigned long flags;
@@ -679,83 +826,6 @@ static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b)
 	return r;
 }
 
-/*----------------------------------------------------------------*/
-
-static void load_stats(struct cache *cache)
-{
-	struct dm_cache_statistics stats;
-
-	dm_cache_metadata_get_stats(cache->cmd, &stats);
-	atomic_set(&cache->stats.read_hit, stats.read_hits);
-	atomic_set(&cache->stats.read_miss, stats.read_misses);
-	atomic_set(&cache->stats.write_hit, stats.write_hits);
-	atomic_set(&cache->stats.write_miss, stats.write_misses);
-}
-
-static void save_stats(struct cache *cache)
-{
-	struct dm_cache_statistics stats;
-
-	if (get_cache_mode(cache) >= CM_READ_ONLY)
-		return;
-
-	stats.read_hits = atomic_read(&cache->stats.read_hit);
-	stats.read_misses = atomic_read(&cache->stats.read_miss);
-	stats.write_hits = atomic_read(&cache->stats.write_hit);
-	stats.write_misses = atomic_read(&cache->stats.write_miss);
-
-	dm_cache_metadata_set_stats(cache->cmd, &stats);
-}
-
-/*----------------------------------------------------------------
- * Per bio data
- *--------------------------------------------------------------*/
-
-/*
- * If using writeback, leave out struct per_bio_data's writethrough fields.
- */
-#define PB_DATA_SIZE_WB (offsetof(struct per_bio_data, cache))
-#define PB_DATA_SIZE_WT (sizeof(struct per_bio_data))
-
-static bool writethrough_mode(struct cache_features *f)
-{
-	return f->io_mode == CM_IO_WRITETHROUGH;
-}
-
-static bool writeback_mode(struct cache_features *f)
-{
-	return f->io_mode == CM_IO_WRITEBACK;
-}
-
-static bool passthrough_mode(struct cache_features *f)
-{
-	return f->io_mode == CM_IO_PASSTHROUGH;
-}
-
-static size_t get_per_bio_data_size(struct cache *cache)
-{
-	return writethrough_mode(&cache->features) ? PB_DATA_SIZE_WT : PB_DATA_SIZE_WB;
-}
-
-static struct per_bio_data *get_per_bio_data(struct bio *bio, size_t data_size)
-{
-	struct per_bio_data *pb = dm_per_bio_data(bio, data_size);
-	BUG_ON(!pb);
-	return pb;
-}
-
-static struct per_bio_data *init_per_bio_data(struct bio *bio, size_t data_size)
-{
-	struct per_bio_data *pb = get_per_bio_data(bio, data_size);
-
-	pb->tick = false;
-	pb->req_nr = dm_bio_get_target_bio_nr(bio);
-	pb->all_io_entry = NULL;
-	pb->len = 0;
-
-	return pb;
-}
-
 /*----------------------------------------------------------------
  * Remapping
  *--------------------------------------------------------------*/
@@ -797,8 +867,9 @@ static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio)
 }
 
 static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio,
-				  dm_oblock_t oblock)
+					  dm_oblock_t oblock)
 {
+	// FIXME: this is called way too much.
 	check_if_tick_bio_needed(cache, bio);
 	remap_to_origin(cache, bio);
 	if (bio_data_dir(bio) == WRITE)
@@ -811,7 +882,7 @@ static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
 	check_if_tick_bio_needed(cache, bio);
 	remap_to_cache(cache, bio, cblock);
 	if (bio_data_dir(bio) == WRITE) {
-		set_dirty(cache, oblock, cblock);
+		set_dirty(cache, cblock);
 		clear_discard(cache, oblock_to_dblock(cache, oblock));
 	}
 }
@@ -828,22 +899,6 @@ static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio)
 	return to_oblock(block_nr);
 }
 
-/*
- * You must increment the deferred set whilst the prison cell is held.  To
- * encourage this, we ask for 'cell' to be passed in.
- */
-static void inc_ds(struct cache *cache, struct bio *bio,
-		   struct dm_bio_prison_cell *cell)
-{
-	size_t pb_data_size = get_per_bio_data_size(cache);
-	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
-
-	BUG_ON(!cell);
-	BUG_ON(pb->all_io_entry);
-
-	pb->all_io_entry = dm_deferred_entry_inc(cache->all_io_ds);
-}
-
 static bool accountable_bio(struct cache *cache, struct bio *bio)
 {
 	return ((bio->bi_bdev == cache->origin_dev->bdev) &&
@@ -875,29 +930,10 @@ static void accounted_request(struct cache *cache, struct bio *bio)
 	generic_make_request(bio);
 }
 
-static void issue(struct cache *cache, struct bio *bio)
-{
-	unsigned long flags;
-
-	if (!op_is_flush(bio->bi_opf)) {
-		accounted_request(cache, bio);
-		return;
-	}
-
-	/*
-	 * Batch together any bios that trigger commits and then issue a
-	 * single commit for them in do_worker().
-	 */
-	spin_lock_irqsave(&cache->lock, flags);
-	cache->commit_requested = true;
-	bio_list_add(&cache->deferred_flush_bios, bio);
-	spin_unlock_irqrestore(&cache->lock, flags);
-}
-
-static void inc_and_issue(struct cache *cache, struct bio *bio, struct dm_bio_prison_cell *cell)
+static void issue_op(struct bio *bio, void *context)
 {
-	inc_ds(cache, bio, cell);
-	issue(cache, bio);
+	struct cache *cache = context;
+	accounted_request(cache, bio);
 }
 
 static void defer_writethrough_bio(struct cache *cache, struct bio *bio)
@@ -908,7 +944,7 @@ static void defer_writethrough_bio(struct cache *cache, struct bio *bio)
 	bio_list_add(&cache->deferred_writethrough_bios, bio);
 	spin_unlock_irqrestore(&cache->lock, flags);
 
-	wake_worker(cache);
+	wake_deferred_writethrough_worker(cache);
 }
 
 static void writethrough_endio(struct bio *bio)
@@ -934,6 +970,7 @@ static void writethrough_endio(struct bio *bio)
 }
 
 /*
+ * FIXME: send in parallel, huge latency as is.
  * When running in writethrough mode we need to send writes to clean blocks
  * to both the cache and origin devices.  In future we'd like to clone the
  * bio and send them in parallel, but for now we're doing them in
@@ -1046,12 +1083,58 @@ static void metadata_operation_failed(struct cache *cache, const char *op, int r
 	set_cache_mode(cache, CM_READ_ONLY);
 }
 
+/*----------------------------------------------------------------*/
+
+static void load_stats(struct cache *cache)
+{
+	struct dm_cache_statistics stats;
+
+	dm_cache_metadata_get_stats(cache->cmd, &stats);
+	atomic_set(&cache->stats.read_hit, stats.read_hits);
+	atomic_set(&cache->stats.read_miss, stats.read_misses);
+	atomic_set(&cache->stats.write_hit, stats.write_hits);
+	atomic_set(&cache->stats.write_miss, stats.write_misses);
+}
+
+static void save_stats(struct cache *cache)
+{
+	struct dm_cache_statistics stats;
+
+	if (get_cache_mode(cache) >= CM_READ_ONLY)
+		return;
+
+	stats.read_hits = atomic_read(&cache->stats.read_hit);
+	stats.read_misses = atomic_read(&cache->stats.read_miss);
+	stats.write_hits = atomic_read(&cache->stats.write_hit);
+	stats.write_misses = atomic_read(&cache->stats.write_miss);
+
+	dm_cache_metadata_set_stats(cache->cmd, &stats);
+}
+
+static void update_stats(struct cache_stats *stats, enum policy_operation op)
+{
+	switch (op) {
+	case POLICY_PROMOTE:
+		atomic_inc(&stats->promotion);
+		break;
+
+	case POLICY_DEMOTE:
+		atomic_inc(&stats->demotion);
+		break;
+
+	case POLICY_WRITEBACK:
+		atomic_inc(&stats->writeback);
+		break;
+	}
+}
+
 /*----------------------------------------------------------------
  * Migration processing
  *
  * Migration covers moving data from the origin device to the cache, or
  * vice versa.
  *--------------------------------------------------------------*/
+
 static void inc_io_migrations(struct cache *cache)
 {
 	atomic_inc(&cache->nr_io_migrations);
@@ -1067,213 +1150,109 @@ static bool discard_or_flush(struct bio *bio)
 	return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf);
 }
 
-static void __cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell)
-{
-	if (discard_or_flush(cell->holder)) {
-		/*
-		 * We have to handle these bios individually.
-		 */
-		dm_cell_release(cache->prison, cell, &cache->deferred_bios);
-		free_prison_cell(cache, cell);
-	} else
-		list_add_tail(&cell->user_list, &cache->deferred_cells);
-}
-
-static void cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell, bool holder)
+static void calc_discard_block_range(struct cache *cache, struct bio *bio,
+				     dm_dblock_t *b, dm_dblock_t *e)
 {
-	unsigned long flags;
-
-	if (!holder && dm_cell_promote_or_release(cache->prison, cell)) {
-		/*
-		 * There was no prisoner to promote to holder, the
-		 * cell has been released.
-		 */
-		free_prison_cell(cache, cell);
-		return;
-	}
+	sector_t sb = bio->bi_iter.bi_sector;
+	sector_t se = bio_end_sector(bio);
 
-	spin_lock_irqsave(&cache->lock, flags);
-	__cell_defer(cache, cell);
-	spin_unlock_irqrestore(&cache->lock, flags);
+	*b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size));
 
-	wake_worker(cache);
+	if (se - sb < cache->discard_block_size)
+		*e = *b;
+	else
+		*e = to_dblock(block_div(se, cache->discard_block_size));
 }
 
-static void cell_error_with_code(struct cache *cache, struct dm_bio_prison_cell *cell, int err)
-{
-	dm_cell_error(cache->prison, cell, err);
-	free_prison_cell(cache, cell);
-}
+/*----------------------------------------------------------------*/
 
-static void cell_requeue(struct cache *cache, struct dm_bio_prison_cell *cell)
+static void prevent_background_work(struct cache *cache)
 {
-	cell_error_with_code(cache, cell, DM_ENDIO_REQUEUE);
+	lockdep_off();
+	down_write(&cache->background_work_lock);
+	lockdep_on();
 }
 
-static void free_io_migration(struct dm_cache_migration *mg)
+static void allow_background_work(struct cache *cache)
 {
-	struct cache *cache = mg->cache;
-
-	dec_io_migrations(cache);
-	free_migration(mg);
-	wake_worker(cache);
+	lockdep_off();
+	up_write(&cache->background_work_lock);
+	lockdep_on();
 }
 
-static void migration_failure(struct dm_cache_migration *mg)
+static bool background_work_begin(struct cache *cache)
 {
-	struct cache *cache = mg->cache;
-	const char *dev_name = cache_device_name(cache);
-
-	if (mg->writeback) {
-		DMERR_LIMIT("%s: writeback failed; couldn't copy block", dev_name);
-		set_dirty(cache, mg->old_oblock, mg->cblock);
-		cell_defer(cache, mg->old_ocell, false);
-
-	} else if (mg->demote) {
-		DMERR_LIMIT("%s: demotion failed; couldn't copy block", dev_name);
-		policy_force_mapping(cache->policy, mg->new_oblock, mg->old_oblock);
+	bool r;
 
-		cell_defer(cache, mg->old_ocell, mg->promote ? false : true);
-		if (mg->promote)
-			cell_defer(cache, mg->new_ocell, true);
-	} else {
-		DMERR_LIMIT("%s: promotion failed; couldn't copy block", dev_name);
-		policy_remove_mapping(cache->policy, mg->new_oblock);
-		cell_defer(cache, mg->new_ocell, true);
-	}
+	lockdep_off();
+	r = down_read_trylock(&cache->background_work_lock);
+	lockdep_on();
 
-	free_io_migration(mg);
+	return r;
 }
 
-static void migration_success_pre_commit(struct dm_cache_migration *mg)
+static void background_work_end(struct cache *cache)
 {
-	int r;
-	unsigned long flags;
-	struct cache *cache = mg->cache;
-
-	if (mg->writeback) {
-		clear_dirty(cache, mg->old_oblock, mg->cblock);
-		cell_defer(cache, mg->old_ocell, false);
-		free_io_migration(mg);
-		return;
+	lockdep_off();
+	up_read(&cache->background_work_lock);
+	lockdep_on();
+}
 
-	} else if (mg->demote) {
-		r = dm_cache_remove_mapping(cache->cmd, mg->cblock);
-		if (r) {
-			DMERR_LIMIT("%s: demotion failed; couldn't update on disk metadata",
-				    cache_device_name(cache));
-			metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
-			policy_force_mapping(cache->policy, mg->new_oblock,
-					     mg->old_oblock);
-			if (mg->promote)
-				cell_defer(cache, mg->new_ocell, true);
-			free_io_migration(mg);
-			return;
-		}
-	} else {
-		r = dm_cache_insert_mapping(cache->cmd, mg->cblock, mg->new_oblock);
-		if (r) {
-			DMERR_LIMIT("%s: promotion failed; couldn't update on disk metadata",
-				    cache_device_name(cache));
-			metadata_operation_failed(cache, "dm_cache_insert_mapping", r);
-			policy_remove_mapping(cache->policy, mg->new_oblock);
-			free_io_migration(mg);
-			return;
-		}
-	}
+/*----------------------------------------------------------------*/
 
-	spin_lock_irqsave(&cache->lock, flags);
-	list_add_tail(&mg->list, &cache->need_commit_migrations);
-	cache->commit_requested = true;
-	spin_unlock_irqrestore(&cache->lock, flags);
+static void quiesce(struct dm_cache_migration *mg,
+		    void (*continuation)(struct work_struct *))
+{
+	init_continuation(&mg->k, continuation);
+	dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws);
 }
 
-static void migration_success_post_commit(struct dm_cache_migration *mg)
+static struct dm_cache_migration *ws_to_mg(struct work_struct *ws)
 {
-	unsigned long flags;
-	struct cache *cache = mg->cache;
-
-	if (mg->writeback) {
-		DMWARN_LIMIT("%s: writeback unexpectedly triggered commit",
-			     cache_device_name(cache));
-		return;
-
-	} else if (mg->demote) {
-		cell_defer(cache, mg->old_ocell, mg->promote ? false : true);
-
-		if (mg->promote) {
-			mg->demote = false;
-
-			spin_lock_irqsave(&cache->lock, flags);
-			list_add_tail(&mg->list, &cache->quiesced_migrations);
-			spin_unlock_irqrestore(&cache->lock, flags);
-
-		} else {
-			if (mg->invalidate)
-				policy_remove_mapping(cache->policy, mg->old_oblock);
-			free_io_migration(mg);
-		}
-
-	} else {
-		if (mg->requeue_holder) {
-			clear_dirty(cache, mg->new_oblock, mg->cblock);
-			cell_defer(cache, mg->new_ocell, true);
-		} else {
-			/*
-			 * The block was promoted via an overwrite, so it's dirty.
-			 */
-			set_dirty(cache, mg->new_oblock, mg->cblock);
-			bio_endio(mg->new_ocell->holder);
-			cell_defer(cache, mg->new_ocell, false);
-		}
-		free_io_migration(mg);
-	}
+	struct continuation *k = container_of(ws, struct continuation, ws);
+	return container_of(k, struct dm_cache_migration, k);
 }
 
 static void copy_complete(int read_err, unsigned long write_err, void *context)
 {
-	unsigned long flags;
-	struct dm_cache_migration *mg = (struct dm_cache_migration *) context;
-	struct cache *cache = mg->cache;
+	struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k);
 
 	if (read_err || write_err)
-		mg->err = true;
+		mg->k.input = -EIO;
 
-	spin_lock_irqsave(&cache->lock, flags);
-	list_add_tail(&mg->list, &cache->completed_migrations);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	wake_worker(cache);
+	queue_continuation(mg->cache->wq, &mg->k);
 }
 
-static void issue_copy(struct dm_cache_migration *mg)
+static int copy(struct dm_cache_migration *mg, bool promote)
 {
 	int r;
 	struct dm_io_region o_region, c_region;
 	struct cache *cache = mg->cache;
-	sector_t cblock = from_cblock(mg->cblock);
 
 	o_region.bdev = cache->origin_dev->bdev;
+	o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block;
 	o_region.count = cache->sectors_per_block;
 
 	c_region.bdev = cache->cache_dev->bdev;
-	c_region.sector = cblock * cache->sectors_per_block;
+	c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block;
 	c_region.count = cache->sectors_per_block;
 
-	if (mg->writeback || mg->demote) {
-		/* demote */
-		o_region.sector = from_oblock(mg->old_oblock) * cache->sectors_per_block;
-		r = dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, mg);
-	} else {
-		/* promote */
-		o_region.sector = from_oblock(mg->new_oblock) * cache->sectors_per_block;
-		r = dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, mg);
-	}
+	if (promote)
+		r = dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k);
+	else
+		r = dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k);
 
-	if (r < 0) {
-		DMERR_LIMIT("%s: issuing migration failed", cache_device_name(cache));
-		migration_failure(mg);
-	}
+	return r;
+}
+
+static void bio_drop_shared_lock(struct cache *cache, struct bio *bio)
+{
+	size_t pb_data_size = get_per_bio_data_size(cache);
+	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
+
+	if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell))
+		free_prison_cell(cache, pb->cell);
+	pb->cell = NULL;
 }
 
 static void overwrite_endio(struct bio *bio)
@@ -1282,368 +1261,475 @@ static void overwrite_endio(struct bio *bio)
 	struct cache *cache = mg->cache;
 	size_t pb_data_size = get_per_bio_data_size(cache);
 	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
-	unsigned long flags;
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
 	if (bio->bi_error)
-		mg->err = true;
-
-	mg->requeue_holder = false;
+		mg->k.input = bio->bi_error;
 
-	spin_lock_irqsave(&cache->lock, flags);
-	list_add_tail(&mg->list, &cache->completed_migrations);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	wake_worker(cache);
+	queue_continuation(mg->cache->wq, &mg->k);
 }
 
-static void issue_overwrite(struct dm_cache_migration *mg, struct bio *bio)
+static void overwrite(struct dm_cache_migration *mg,
+		      void (*continuation)(struct work_struct *))
 {
+	struct bio *bio = mg->overwrite_bio;
 	size_t pb_data_size = get_per_bio_data_size(mg->cache);
 	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
 
 	dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg);
-	remap_to_cache_dirty(mg->cache, bio, mg->new_oblock, mg->cblock);
 
 	/*
-	 * No need to inc_ds() here, since the cell will be held for the
-	 * duration of the io.
+	 * The overwrite bio is part of the copy operation, as such it does
+	 * not set/clear discard or dirty flags.
 	 */
+	if (mg->op->op == POLICY_PROMOTE)
+		remap_to_cache(mg->cache, bio, mg->op->cblock);
+	else
+		remap_to_origin(mg->cache, bio);
+
+	init_continuation(&mg->k, continuation);
 	accounted_request(mg->cache, bio);
 }
 
-static bool bio_writes_complete_block(struct cache *cache, struct bio *bio)
+/*
+ * Migration steps:
+ *
+ * 1) exclusive lock preventing WRITEs
+ * 2) quiesce
+ * 3) copy or issue overwrite bio
+ * 4) upgrade to exclusive lock preventing READs and WRITEs
+ * 5) quiesce
+ * 6) update metadata and commit
+ * 7) unlock
+ */
+static void mg_complete(struct dm_cache_migration *mg, bool success)
 {
-	return (bio_data_dir(bio) == WRITE) &&
-		(bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT));
-}
+	struct bio_list bios;
+	struct cache *cache = mg->cache;
+	struct policy_work *op = mg->op;
+	dm_cblock_t cblock = op->cblock;
+
+	if (success)
+		update_stats(&cache->stats, op->op);
+
+	switch (op->op) {
+	case POLICY_PROMOTE:
+		clear_discard(cache, oblock_to_dblock(cache, op->oblock));
+		policy_complete_background_work(cache->policy, op, success);
+
+		if (mg->overwrite_bio) {
+			if (success)
+				force_set_dirty(cache, cblock);
+			else
+				mg->overwrite_bio->bi_error = (mg->k.input ? : -EIO);
+			bio_endio(mg->overwrite_bio);
+		} else {
+			if (success)
+				force_clear_dirty(cache, cblock);
+			dec_io_migrations(cache);
+		}
+		break;
 
-static void avoid_copy(struct dm_cache_migration *mg)
-{
-	atomic_inc(&mg->cache->stats.copies_avoided);
-	migration_success_pre_commit(mg);
-}
+	case POLICY_DEMOTE:
+		/*
+		 * We clear dirty here to update the nr_dirty counter.
+		 */
+		if (success)
+			force_clear_dirty(cache, cblock);
+		policy_complete_background_work(cache->policy, op, success);
+		dec_io_migrations(cache);
+		break;
 
-static void calc_discard_block_range(struct cache *cache, struct bio *bio,
-				     dm_dblock_t *b, dm_dblock_t *e)
-{
-	sector_t sb = bio->bi_iter.bi_sector;
-	sector_t se = bio_end_sector(bio);
+	case POLICY_WRITEBACK:
+		if (success)
+			force_clear_dirty(cache, cblock);
+		policy_complete_background_work(cache->policy, op, success);
+		dec_io_migrations(cache);
+		break;
+	}
 
-	*b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size));
+	bio_list_init(&bios);
+	if (mg->cell) {
+		if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios))
+			free_prison_cell(cache, mg->cell);
+	}
 
-	if (se - sb < cache->discard_block_size)
-		*e = *b;
-	else
-		*e = to_dblock(block_div(se, cache->discard_block_size));
+	free_migration(mg);
+	defer_bios(cache, &bios);
+	wake_migration_worker(cache);
+
+	background_work_end(cache);
 }
 
-static void issue_discard(struct dm_cache_migration *mg)
+static void mg_success(struct work_struct *ws)
 {
-	dm_dblock_t b, e;
-	struct bio *bio = mg->new_ocell->holder;
-	struct cache *cache = mg->cache;
-
-	calc_discard_block_range(cache, bio, &b, &e);
-	while (b != e) {
-		set_discard(cache, b);
-		b = to_dblock(from_dblock(b) + 1);
-	}
-
-	bio_endio(bio);
-	cell_defer(cache, mg->new_ocell, false);
-	free_migration(mg);
-	wake_worker(cache);
+	struct dm_cache_migration *mg = ws_to_mg(ws);
+	mg_complete(mg, mg->k.input == 0);
 }
 
-static void issue_copy_or_discard(struct dm_cache_migration *mg)
+static void mg_update_metadata(struct work_struct *ws)
 {
-	bool avoid;
+	int r;
+	struct dm_cache_migration *mg = ws_to_mg(ws);
 	struct cache *cache = mg->cache;
+	struct policy_work *op = mg->op;
 
-	if (mg->discard) {
-		issue_discard(mg);
-		return;
-	}
+	switch (op->op) {
+	case POLICY_PROMOTE:
+		r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock);
+		if (r) {
+			DMERR_LIMIT("%s: migration failed; couldn't insert mapping",
+				    cache_device_name(cache));
+			metadata_operation_failed(cache, "dm_cache_insert_mapping", r);
 
-	if (mg->writeback || mg->demote)
-		avoid = !is_dirty(cache, mg->cblock) ||
-			is_discarded_oblock(cache, mg->old_oblock);
-	else {
-		struct bio *bio = mg->new_ocell->holder;
+			mg_complete(mg, false);
+			return;
+		}
+		mg_complete(mg, true);
+		break;
 
-		avoid = is_discarded_oblock(cache, mg->new_oblock);
+	case POLICY_DEMOTE:
+		r = dm_cache_remove_mapping(cache->cmd, op->cblock);
+		if (r) {
+			DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata",
+				    cache_device_name(cache));
+			metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
 
-		if (writeback_mode(&cache->features) &&
-		    !avoid && bio_writes_complete_block(cache, bio)) {
-			issue_overwrite(mg, bio);
+			mg_complete(mg, false);
 			return;
 		}
-	}
 
-	avoid ? avoid_copy(mg) : issue_copy(mg);
+		/*
+		 * It would be nice if we only had to commit when a REQ_FLUSH
+		 * comes through.  But there's one scenario that we have to
+		 * look out for:
+		 *
+		 * - vblock x in a cache block
+		 * - domotion occurs
+		 * - cache block gets reallocated and over written
+		 * - crash
+		 *
+		 * When we recover, because there was no commit the cache will
+		 * rollback to having the data for vblock x in the cache block.
+		 * But the cache block has since been overwritten, so it'll end
+		 * up pointing to data that was never in 'x' during the history
+		 * of the device.
+		 *
+		 * To avoid this issue we require a commit as part of the
+		 * demotion operation.
+		 */
+		init_continuation(&mg->k, mg_success);
+		continue_after_commit(&cache->committer, &mg->k);
+		schedule_commit(&cache->committer);
+		break;
+
+	case POLICY_WRITEBACK:
+		mg_complete(mg, true);
+		break;
+	}
 }
 
-static void complete_migration(struct dm_cache_migration *mg)
+static void mg_update_metadata_after_copy(struct work_struct *ws)
 {
-	if (mg->err)
-		migration_failure(mg);
+	struct dm_cache_migration *mg = ws_to_mg(ws);
+
+	/*
+	 * Did the copy succeed?
+	 */
+	if (mg->k.input)
+		mg_complete(mg, false);
 	else
-		migration_success_pre_commit(mg);
+		mg_update_metadata(ws);
 }
 
-static void process_migrations(struct cache *cache, struct list_head *head,
-			       void (*fn)(struct dm_cache_migration *))
+static void mg_upgrade_lock(struct work_struct *ws)
 {
-	unsigned long flags;
-	struct list_head list;
-	struct dm_cache_migration *mg, *tmp;
+	int r;
+	struct dm_cache_migration *mg = ws_to_mg(ws);
 
-	INIT_LIST_HEAD(&list);
-	spin_lock_irqsave(&cache->lock, flags);
-	list_splice_init(head, &list);
-	spin_unlock_irqrestore(&cache->lock, flags);
+	/*
+	 * Did the copy succeed?
+	 */
+	if (mg->k.input)
+		mg_complete(mg, false);
 
-	list_for_each_entry_safe(mg, tmp, &list, list)
-		fn(mg);
-}
+	else {
+		/*
+		 * Now we want the lock to prevent both reads and writes.
+		 */
+		r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell,
+					    READ_WRITE_LOCK_LEVEL);
+		if (r < 0)
+			mg_complete(mg, false);
 
-static void __queue_quiesced_migration(struct dm_cache_migration *mg)
-{
-	list_add_tail(&mg->list, &mg->cache->quiesced_migrations);
+		else if (r)
+			quiesce(mg, mg_update_metadata);
+
+		else
+			mg_update_metadata(ws);
+	}
 }
 
-static void queue_quiesced_migration(struct dm_cache_migration *mg)
+static void mg_copy(struct work_struct *ws)
 {
-	unsigned long flags;
-	struct cache *cache = mg->cache;
+	int r;
+	struct dm_cache_migration *mg = ws_to_mg(ws);
 
-	spin_lock_irqsave(&cache->lock, flags);
-	__queue_quiesced_migration(mg);
-	spin_unlock_irqrestore(&cache->lock, flags);
+	if (mg->overwrite_bio) {
+		/*
+		 * It's safe to do this here, even though it's new data
+		 * because all IO has been locked out of the block.
+		 *
+		 * mg_lock_writes() already took READ_WRITE_LOCK_LEVEL
+		 * so _not_ using mg_upgrade_lock() as continutation.
+		 */
+		overwrite(mg, mg_update_metadata_after_copy);
 
-	wake_worker(cache);
-}
+	} else {
+		struct cache *cache = mg->cache;
+		struct policy_work *op = mg->op;
+		bool is_policy_promote = (op->op == POLICY_PROMOTE);
 
-static void queue_quiesced_migrations(struct cache *cache, struct list_head *work)
-{
-	unsigned long flags;
-	struct dm_cache_migration *mg, *tmp;
+		if ((!is_policy_promote && !is_dirty(cache, op->cblock)) ||
+		    is_discarded_oblock(cache, op->oblock)) {
+			mg_upgrade_lock(ws);
+			return;
+		}
 
-	spin_lock_irqsave(&cache->lock, flags);
-	list_for_each_entry_safe(mg, tmp, work, list)
-		__queue_quiesced_migration(mg);
-	spin_unlock_irqrestore(&cache->lock, flags);
+		init_continuation(&mg->k, mg_upgrade_lock);
 
-	wake_worker(cache);
+		r = copy(mg, is_policy_promote);
+		if (r) {
+			DMERR_LIMIT("%s: migration copy failed", cache_device_name(cache));
+			mg->k.input = -EIO;
+			mg_complete(mg, false);
+		}
+	}
 }
 
-static void check_for_quiesced_migrations(struct cache *cache,
-					  struct per_bio_data *pb)
+static int mg_lock_writes(struct dm_cache_migration *mg)
 {
-	struct list_head work;
+	int r;
+	struct dm_cell_key_v2 key;
+	struct cache *cache = mg->cache;
+	struct dm_bio_prison_cell_v2 *prealloc;
 
-	if (!pb->all_io_entry)
-		return;
+	prealloc = alloc_prison_cell(cache);
+	if (!prealloc) {
+		DMERR_LIMIT("%s: alloc_prison_cell failed", cache_device_name(cache));
+		mg_complete(mg, false);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Prevent writes to the block, but allow reads to continue.
+	 * Unless we're using an overwrite bio, in which case we lock
+	 * everything.
+	 */
+	build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key);
+	r = dm_cell_lock_v2(cache->prison, &key,
+			    mg->overwrite_bio ?  READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL,
+			    prealloc, &mg->cell);
+	if (r < 0) {
+		free_prison_cell(cache, prealloc);
+		mg_complete(mg, false);
+		return r;
+	}
 
-	INIT_LIST_HEAD(&work);
-	dm_deferred_entry_dec(pb->all_io_entry, &work);
+	if (mg->cell != prealloc)
+		free_prison_cell(cache, prealloc);
 
-	if (!list_empty(&work))
-		queue_quiesced_migrations(cache, &work);
-}
+	if (r == 0)
+		mg_copy(&mg->k.ws);
+	else
+		quiesce(mg, mg_copy);
 
-static void quiesce_migration(struct dm_cache_migration *mg)
-{
-	if (!dm_deferred_set_add_work(mg->cache->all_io_ds, &mg->list))
-		queue_quiesced_migration(mg);
+	return 0;
 }
 
-static void promote(struct cache *cache, struct prealloc *structs,
-		    dm_oblock_t oblock, dm_cblock_t cblock,
-		    struct dm_bio_prison_cell *cell)
+static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio)
 {
-	struct dm_cache_migration *mg = prealloc_get_migration(structs);
+	struct dm_cache_migration *mg;
+
+	if (!background_work_begin(cache)) {
+		policy_complete_background_work(cache->policy, op, false);
+		return -EPERM;
+	}
+
+	mg = alloc_migration(cache);
+	if (!mg) {
+		policy_complete_background_work(cache->policy, op, false);
+		background_work_end(cache);
+		return -ENOMEM;
+	}
+
+	memset(mg, 0, sizeof(*mg));
 
-	mg->err = false;
-	mg->discard = false;
-	mg->writeback = false;
-	mg->demote = false;
-	mg->promote = true;
-	mg->requeue_holder = true;
-	mg->invalidate = false;
 	mg->cache = cache;
-	mg->new_oblock = oblock;
-	mg->cblock = cblock;
-	mg->old_ocell = NULL;
-	mg->new_ocell = cell;
-	mg->start_jiffies = jiffies;
+	mg->op = op;
+	mg->overwrite_bio = bio;
+
+	if (!bio)
+		inc_io_migrations(cache);
 
-	inc_io_migrations(cache);
-	quiesce_migration(mg);
+	return mg_lock_writes(mg);
 }
 
-static void writeback(struct cache *cache, struct prealloc *structs,
-		      dm_oblock_t oblock, dm_cblock_t cblock,
-		      struct dm_bio_prison_cell *cell)
+/*----------------------------------------------------------------
+ * invalidation processing
+ *--------------------------------------------------------------*/
+
+static void invalidate_complete(struct dm_cache_migration *mg, bool success)
 {
-	struct dm_cache_migration *mg = prealloc_get_migration(structs);
+	struct bio_list bios;
+	struct cache *cache = mg->cache;
 
-	mg->err = false;
-	mg->discard = false;
-	mg->writeback = true;
-	mg->demote = false;
-	mg->promote = false;
-	mg->requeue_holder = true;
-	mg->invalidate = false;
-	mg->cache = cache;
-	mg->old_oblock = oblock;
-	mg->cblock = cblock;
-	mg->old_ocell = cell;
-	mg->new_ocell = NULL;
-	mg->start_jiffies = jiffies;
-
-	inc_io_migrations(cache);
-	quiesce_migration(mg);
-}
-
-static void demote_then_promote(struct cache *cache, struct prealloc *structs,
-				dm_oblock_t old_oblock, dm_oblock_t new_oblock,
-				dm_cblock_t cblock,
-				struct dm_bio_prison_cell *old_ocell,
-				struct dm_bio_prison_cell *new_ocell)
-{
-	struct dm_cache_migration *mg = prealloc_get_migration(structs);
-
-	mg->err = false;
-	mg->discard = false;
-	mg->writeback = false;
-	mg->demote = true;
-	mg->promote = true;
-	mg->requeue_holder = true;
-	mg->invalidate = false;
-	mg->cache = cache;
-	mg->old_oblock = old_oblock;
-	mg->new_oblock = new_oblock;
-	mg->cblock = cblock;
-	mg->old_ocell = old_ocell;
-	mg->new_ocell = new_ocell;
-	mg->start_jiffies = jiffies;
+	bio_list_init(&bios);
+	if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios))
+		free_prison_cell(cache, mg->cell);
 
-	inc_io_migrations(cache);
-	quiesce_migration(mg);
-}
+	if (!success && mg->overwrite_bio)
+		bio_io_error(mg->overwrite_bio);
 
-/*
- * Invalidate a cache entry.  No writeback occurs; any changes in the cache
- * block are thrown away.
- */
-static void invalidate(struct cache *cache, struct prealloc *structs,
-		       dm_oblock_t oblock, dm_cblock_t cblock,
-		       struct dm_bio_prison_cell *cell)
-{
-	struct dm_cache_migration *mg = prealloc_get_migration(structs);
-
-	mg->err = false;
-	mg->discard = false;
-	mg->writeback = false;
-	mg->demote = true;
-	mg->promote = false;
-	mg->requeue_holder = true;
-	mg->invalidate = true;
-	mg->cache = cache;
-	mg->old_oblock = oblock;
-	mg->cblock = cblock;
-	mg->old_ocell = cell;
-	mg->new_ocell = NULL;
-	mg->start_jiffies = jiffies;
+	free_migration(mg);
+	defer_bios(cache, &bios);
 
-	inc_io_migrations(cache);
-	quiesce_migration(mg);
+	background_work_end(cache);
 }
 
-static void discard(struct cache *cache, struct prealloc *structs,
-		    struct dm_bio_prison_cell *cell)
+static void invalidate_completed(struct work_struct *ws)
 {
-	struct dm_cache_migration *mg = prealloc_get_migration(structs);
+	struct dm_cache_migration *mg = ws_to_mg(ws);
+	invalidate_complete(mg, !mg->k.input);
+}
 
-	mg->err = false;
-	mg->discard = true;
-	mg->writeback = false;
-	mg->demote = false;
-	mg->promote = false;
-	mg->requeue_holder = false;
-	mg->invalidate = false;
-	mg->cache = cache;
-	mg->old_ocell = NULL;
-	mg->new_ocell = cell;
-	mg->start_jiffies = jiffies;
+static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock)
+{
+	int r = policy_invalidate_mapping(cache->policy, cblock);
+	if (!r) {
+		r = dm_cache_remove_mapping(cache->cmd, cblock);
+		if (r) {
+			DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata",
+				    cache_device_name(cache));
+			metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
+		}
+
+	} else if (r == -ENODATA) {
+		/*
+		 * Harmless, already unmapped.
+		 */
+		r = 0;
+
+	} else
+		DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache));
 
-	quiesce_migration(mg);
+	return r;
 }
 
-/*----------------------------------------------------------------
- * bio processing
- *--------------------------------------------------------------*/
-static void defer_bio(struct cache *cache, struct bio *bio)
+static void invalidate_remove(struct work_struct *ws)
 {
-	unsigned long flags;
+	int r;
+	struct dm_cache_migration *mg = ws_to_mg(ws);
+	struct cache *cache = mg->cache;
 
-	spin_lock_irqsave(&cache->lock, flags);
-	bio_list_add(&cache->deferred_bios, bio);
-	spin_unlock_irqrestore(&cache->lock, flags);
+	r = invalidate_cblock(cache, mg->invalidate_cblock);
+	if (r) {
+		invalidate_complete(mg, false);
+		return;
+	}
 
-	wake_worker(cache);
+	init_continuation(&mg->k, invalidate_completed);
+	continue_after_commit(&cache->committer, &mg->k);
+	remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock);
+	mg->overwrite_bio = NULL;
+	schedule_commit(&cache->committer);
 }
 
-static void process_flush_bio(struct cache *cache, struct bio *bio)
+static int invalidate_lock(struct dm_cache_migration *mg)
 {
-	size_t pb_data_size = get_per_bio_data_size(cache);
-	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
+	int r;
+	struct dm_cell_key_v2 key;
+	struct cache *cache = mg->cache;
+	struct dm_bio_prison_cell_v2 *prealloc;
 
-	BUG_ON(bio->bi_iter.bi_size);
-	if (!pb->req_nr)
-		remap_to_origin(cache, bio);
-	else
-		remap_to_cache(cache, bio, 0);
+	prealloc = alloc_prison_cell(cache);
+	if (!prealloc) {
+		invalidate_complete(mg, false);
+		return -ENOMEM;
+	}
 
-	/*
-	 * REQ_PREFLUSH is not directed at any particular block so we don't
-	 * need to inc_ds().  REQ_FUA's are split into a write + REQ_PREFLUSH
-	 * by dm-core.
-	 */
-	issue(cache, bio);
+	build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key);
+	r = dm_cell_lock_v2(cache->prison, &key,
+			    READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell);
+	if (r < 0) {
+		free_prison_cell(cache, prealloc);
+		invalidate_complete(mg, false);
+		return r;
+	}
+
+	if (mg->cell != prealloc)
+		free_prison_cell(cache, prealloc);
+
+	if (r)
+		quiesce(mg, invalidate_remove);
+
+	else {
+		/*
+		 * We can't call invalidate_remove() directly here because we
+		 * might still be in request context.
+		 */
+		init_continuation(&mg->k, invalidate_remove);
+		queue_work(cache->wq, &mg->k.ws);
+	}
+
+	return 0;
 }
 
-static void process_discard_bio(struct cache *cache, struct prealloc *structs,
-				struct bio *bio)
+static int invalidate_start(struct cache *cache, dm_cblock_t cblock,
+			    dm_oblock_t oblock, struct bio *bio)
 {
-	int r;
-	dm_dblock_t b, e;
-	struct dm_bio_prison_cell *cell_prealloc, *new_ocell;
+	struct dm_cache_migration *mg;
 
-	calc_discard_block_range(cache, bio, &b, &e);
-	if (b == e) {
-		bio_endio(bio);
-		return;
+	if (!background_work_begin(cache))
+		return -EPERM;
+
+	mg = alloc_migration(cache);
+	if (!mg) {
+		background_work_end(cache);
+		return -ENOMEM;
 	}
 
-	cell_prealloc = prealloc_get_cell(structs);
-	r = bio_detain_range(cache, dblock_to_oblock(cache, b), dblock_to_oblock(cache, e), bio, cell_prealloc,
-			     (cell_free_fn) prealloc_put_cell,
-			     structs, &new_ocell);
-	if (r > 0)
-		return;
+	memset(mg, 0, sizeof(*mg));
+
+	mg->cache = cache;
+	mg->overwrite_bio = bio;
+	mg->invalidate_cblock = cblock;
+	mg->invalidate_oblock = oblock;
 
-	discard(cache, structs, new_ocell);
+	return invalidate_lock(mg);
 }
 
-static bool spare_migration_bandwidth(struct cache *cache)
+/*----------------------------------------------------------------
+ * bio processing
+ *--------------------------------------------------------------*/
+
+enum busy {
+	IDLE,
+	MODERATE,
+	BUSY
+};
+
+static enum busy spare_migration_bandwidth(struct cache *cache)
 {
+	bool idle = iot_idle_for(&cache->origin_tracker, HZ);
 	sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) *
 		cache->sectors_per_block;
-	return current_volume < cache->migration_threshold;
+
+	if (current_volume <= cache->migration_threshold)
+		return idle ? IDLE : MODERATE;
+	else
+		return idle ? MODERATE : BUSY;
 }
 
 static void inc_hit_counter(struct cache *cache, struct bio *bio)
@@ -1660,255 +1746,143 @@ static void inc_miss_counter(struct cache *cache, struct bio *bio)
 
 /*----------------------------------------------------------------*/
 
-struct inc_detail {
-	struct cache *cache;
-	struct bio_list bios_for_issue;
-	struct bio_list unhandled_bios;
-	bool any_writes;
-};
-
-static void inc_fn(void *context, struct dm_bio_prison_cell *cell)
+static bool bio_writes_complete_block(struct cache *cache, struct bio *bio)
 {
-	struct bio *bio;
-	struct inc_detail *detail = context;
-	struct cache *cache = detail->cache;
-
-	inc_ds(cache, cell->holder, cell);
-	if (bio_data_dir(cell->holder) == WRITE)
-		detail->any_writes = true;
-
-	while ((bio = bio_list_pop(&cell->bios))) {
-		if (discard_or_flush(bio)) {
-			bio_list_add(&detail->unhandled_bios, bio);
-			continue;
-		}
-
-		if (bio_data_dir(bio) == WRITE)
-			detail->any_writes = true;
-
-		bio_list_add(&detail->bios_for_issue, bio);
-		inc_ds(cache, bio, cell);
-	}
+	return (bio_data_dir(bio) == WRITE) &&
+		(bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT));
 }
 
-// FIXME: refactor these two
-static void remap_cell_to_origin_clear_discard(struct cache *cache,
-					       struct dm_bio_prison_cell *cell,
-					       dm_oblock_t oblock, bool issue_holder)
+static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block)
 {
-	struct bio *bio;
-	unsigned long flags;
-	struct inc_detail detail;
-
-	detail.cache = cache;
-	bio_list_init(&detail.bios_for_issue);
-	bio_list_init(&detail.unhandled_bios);
-	detail.any_writes = false;
-
-	spin_lock_irqsave(&cache->lock, flags);
-	dm_cell_visit_release(cache->prison, inc_fn, &detail, cell);
-	bio_list_merge(&cache->deferred_bios, &detail.unhandled_bios);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	remap_to_origin(cache, cell->holder);
-	if (issue_holder)
-		issue(cache, cell->holder);
-	else
-		accounted_begin(cache, cell->holder);
-
-	if (detail.any_writes)
-		clear_discard(cache, oblock_to_dblock(cache, oblock));
-
-	while ((bio = bio_list_pop(&detail.bios_for_issue))) {
-		remap_to_origin(cache, bio);
-		issue(cache, bio);
-	}
-
-	free_prison_cell(cache, cell);
+	return writeback_mode(&cache->features) &&
+		(is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio));
 }
 
-static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_cell *cell,
-				      dm_oblock_t oblock, dm_cblock_t cblock, bool issue_holder)
+static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block,
+		   bool *commit_needed)
 {
-	struct bio *bio;
-	unsigned long flags;
-	struct inc_detail detail;
-
-	detail.cache = cache;
-	bio_list_init(&detail.bios_for_issue);
-	bio_list_init(&detail.unhandled_bios);
-	detail.any_writes = false;
-
-	spin_lock_irqsave(&cache->lock, flags);
-	dm_cell_visit_release(cache->prison, inc_fn, &detail, cell);
-	bio_list_merge(&cache->deferred_bios, &detail.unhandled_bios);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	remap_to_cache(cache, cell->holder, cblock);
-	if (issue_holder)
-		issue(cache, cell->holder);
-	else
-		accounted_begin(cache, cell->holder);
+	int r, data_dir;
+	bool rb, background_queued;
+	dm_cblock_t cblock;
+	size_t pb_data_size = get_per_bio_data_size(cache);
+	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
 
-	if (detail.any_writes) {
-		set_dirty(cache, oblock, cblock);
-		clear_discard(cache, oblock_to_dblock(cache, oblock));
-	}
+	*commit_needed = false;
 
-	while ((bio = bio_list_pop(&detail.bios_for_issue))) {
-		remap_to_cache(cache, bio, cblock);
-		issue(cache, bio);
+	rb = bio_detain_shared(cache, block, bio);
+	if (!rb) {
+		/*
+		 * An exclusive lock is held for this block, so we have to
+		 * wait.  We set the commit_needed flag so the current
+		 * transaction will be committed asap, allowing this lock
+		 * to be dropped.
+		 */
+		*commit_needed = true;
+		return DM_MAPIO_SUBMITTED;
 	}
 
-	free_prison_cell(cache, cell);
-}
+	data_dir = bio_data_dir(bio);
 
-/*----------------------------------------------------------------*/
+	if (optimisable_bio(cache, bio, block)) {
+		struct policy_work *op = NULL;
 
-struct old_oblock_lock {
-	struct policy_locker locker;
-	struct cache *cache;
-	struct prealloc *structs;
-	struct dm_bio_prison_cell *cell;
-};
-
-static int null_locker(struct policy_locker *locker, dm_oblock_t b)
-{
-	/* This should never be called */
-	BUG();
-	return 0;
-}
+		r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op);
+		if (unlikely(r && r != -ENOENT)) {
+			DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d",
+				    cache_device_name(cache), r);
+			bio_io_error(bio);
+			return DM_MAPIO_SUBMITTED;
+		}
 
-static int cell_locker(struct policy_locker *locker, dm_oblock_t b)
-{
-	struct old_oblock_lock *l = container_of(locker, struct old_oblock_lock, locker);
-	struct dm_bio_prison_cell *cell_prealloc = prealloc_get_cell(l->structs);
+		if (r == -ENOENT && op) {
+			bio_drop_shared_lock(cache, bio);
+			BUG_ON(op->op != POLICY_PROMOTE);
+			mg_start(cache, op, bio);
+			return DM_MAPIO_SUBMITTED;
+		}
+	} else {
+		r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued);
+		if (unlikely(r && r != -ENOENT)) {
+			DMERR_LIMIT("%s: policy_lookup() failed with r = %d",
+				    cache_device_name(cache), r);
+			bio_io_error(bio);
+			return DM_MAPIO_SUBMITTED;
+		}
 
-	return bio_detain(l->cache, b, NULL, cell_prealloc,
-			  (cell_free_fn) prealloc_put_cell,
-			  l->structs, &l->cell);
-}
+		if (background_queued)
+			wake_migration_worker(cache);
+	}
 
-static void process_cell(struct cache *cache, struct prealloc *structs,
-			 struct dm_bio_prison_cell *new_ocell)
-{
-	int r;
-	bool release_cell = true;
-	struct bio *bio = new_ocell->holder;
-	dm_oblock_t block = get_bio_block(cache, bio);
-	struct policy_result lookup_result;
-	bool passthrough = passthrough_mode(&cache->features);
-	bool fast_promotion, can_migrate;
-	struct old_oblock_lock ool;
-
-	fast_promotion = is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio);
-	can_migrate = !passthrough && (fast_promotion || spare_migration_bandwidth(cache));
-
-	ool.locker.fn = cell_locker;
-	ool.cache = cache;
-	ool.structs = structs;
-	ool.cell = NULL;
-	r = policy_map(cache->policy, block, true, can_migrate, fast_promotion,
-		       bio, &ool.locker, &lookup_result);
-
-	if (r == -EWOULDBLOCK)
-		/* migration has been denied */
-		lookup_result.op = POLICY_MISS;
-
-	switch (lookup_result.op) {
-	case POLICY_HIT:
-		if (passthrough) {
-			inc_miss_counter(cache, bio);
+	if (r == -ENOENT) {
+		/*
+		 * Miss.
+		 */
+		inc_miss_counter(cache, bio);
+		if (pb->req_nr == 0) {
+			accounted_begin(cache, bio);
+			remap_to_origin_clear_discard(cache, bio, block);
 
+		} else {
 			/*
-			 * Passthrough always maps to the origin,
-			 * invalidating any cache blocks that are written
-			 * to.
+			 * This is a duplicate writethrough io that is no
+			 * longer needed because the block has been demoted.
 			 */
+			bio_endio(bio);
+			return DM_MAPIO_SUBMITTED;
+		}
+	} else {
+		/*
+		 * Hit.
+		 */
+		inc_hit_counter(cache, bio);
 
+		/*
+		 * Passthrough always maps to the origin, invalidating any
+		 * cache blocks that are written to.
+		 */
+		if (passthrough_mode(&cache->features)) {
 			if (bio_data_dir(bio) == WRITE) {
+				bio_drop_shared_lock(cache, bio);
 				atomic_inc(&cache->stats.demotion);
-				invalidate(cache, structs, block, lookup_result.cblock, new_ocell);
-				release_cell = false;
-
-			} else {
-				/* FIXME: factor out issue_origin() */
+				invalidate_start(cache, cblock, block, bio);
+			} else
 				remap_to_origin_clear_discard(cache, bio, block);
-				inc_and_issue(cache, bio, new_ocell);
-			}
+
 		} else {
-			inc_hit_counter(cache, bio);
-
-			if (bio_data_dir(bio) == WRITE &&
-			    writethrough_mode(&cache->features) &&
-			    !is_dirty(cache, lookup_result.cblock)) {
-				remap_to_origin_then_cache(cache, bio, block, lookup_result.cblock);
-				inc_and_issue(cache, bio, new_ocell);
-
-			} else {
-				remap_cell_to_cache_dirty(cache, new_ocell, block, lookup_result.cblock, true);
-				release_cell = false;
-			}
+			if (bio_data_dir(bio) == WRITE && writethrough_mode(&cache->features) &&
+			    !is_dirty(cache, cblock)) {
+				remap_to_origin_then_cache(cache, bio, block, cblock);
+				accounted_begin(cache, bio);
+			} else
+				remap_to_cache_dirty(cache, bio, block, cblock);
 		}
-
-		break;
-
-	case POLICY_MISS:
-		inc_miss_counter(cache, bio);
-		remap_cell_to_origin_clear_discard(cache, new_ocell, block, true);
-		release_cell = false;
-		break;
-
-	case POLICY_NEW:
-		atomic_inc(&cache->stats.promotion);
-		promote(cache, structs, block, lookup_result.cblock, new_ocell);
-		release_cell = false;
-		break;
-
-	case POLICY_REPLACE:
-		atomic_inc(&cache->stats.demotion);
-		atomic_inc(&cache->stats.promotion);
-		demote_then_promote(cache, structs, lookup_result.old_oblock,
-				    block, lookup_result.cblock,
-				    ool.cell, new_ocell);
-		release_cell = false;
-		break;
-
-	default:
-		DMERR_LIMIT("%s: %s: erroring bio, unknown policy op: %u",
-			    cache_device_name(cache), __func__,
-			    (unsigned) lookup_result.op);
-		bio_io_error(bio);
 	}
 
-	if (release_cell)
-		cell_defer(cache, new_ocell, false);
-}
-
-static void process_bio(struct cache *cache, struct prealloc *structs,
-			struct bio *bio)
-{
-	int r;
-	dm_oblock_t block = get_bio_block(cache, bio);
-	struct dm_bio_prison_cell *cell_prealloc, *new_ocell;
-
 	/*
-	 * Check to see if that block is currently migrating.
+	 * dm core turns FUA requests into a separate payload and FLUSH req.
 	 */
-	cell_prealloc = prealloc_get_cell(structs);
-	r = bio_detain(cache, block, bio, cell_prealloc,
-		       (cell_free_fn) prealloc_put_cell,
-		       structs, &new_ocell);
-	if (r > 0)
-		return;
+	if (bio->bi_opf & REQ_FUA) {
+		/*
+		 * issue_after_commit will call accounted_begin a second time.  So
+		 * we call accounted_complete() to avoid double accounting.
+		 */
+		accounted_complete(cache, bio);
+		issue_after_commit(&cache->committer, bio);
+		*commit_needed = true;
+		return DM_MAPIO_SUBMITTED;
+	}
 
-	process_cell(cache, structs, new_ocell);
+	return DM_MAPIO_REMAPPED;
 }
 
-static int need_commit_due_to_time(struct cache *cache)
+static bool process_bio(struct cache *cache, struct bio *bio)
 {
-	return jiffies < cache->last_commit_jiffies ||
-	       jiffies > cache->last_commit_jiffies + COMMIT_PERIOD;
+	bool commit_needed;
+
+	if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED)
+		generic_make_request(bio);
+
+	return commit_needed;
 }
 
 /*
@@ -1929,123 +1903,88 @@ static int commit(struct cache *cache, bool clean_shutdown)
 	return r;
 }
 
-static int commit_if_needed(struct cache *cache)
+/*
+ * Used by the batcher.
+ */
+static int commit_op(void *context)
 {
-	int r = 0;
+	struct cache *cache = context;
 
-	if ((cache->commit_requested || need_commit_due_to_time(cache)) &&
-	    dm_cache_changed_this_transaction(cache->cmd)) {
-		r = commit(cache, false);
-		cache->commit_requested = false;
-		cache->last_commit_jiffies = jiffies;
-	}
+	if (dm_cache_changed_this_transaction(cache->cmd))
+		return commit(cache, false);
 
-	return r;
+	return 0;
 }
 
-static void process_deferred_bios(struct cache *cache)
-{
-	bool prealloc_used = false;
-	unsigned long flags;
-	struct bio_list bios;
-	struct bio *bio;
-	struct prealloc structs;
-
-	memset(&structs, 0, sizeof(structs));
-	bio_list_init(&bios);
-
-	spin_lock_irqsave(&cache->lock, flags);
-	bio_list_merge(&bios, &cache->deferred_bios);
-	bio_list_init(&cache->deferred_bios);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	while (!bio_list_empty(&bios)) {
-		/*
-		 * If we've got no free migration structs, and processing
-		 * this bio might require one, we pause until there are some
-		 * prepared mappings to process.
-		 */
-		prealloc_used = true;
-		if (prealloc_data_structs(cache, &structs)) {
-			spin_lock_irqsave(&cache->lock, flags);
-			bio_list_merge(&cache->deferred_bios, &bios);
-			spin_unlock_irqrestore(&cache->lock, flags);
-			break;
-		}
+/*----------------------------------------------------------------*/
 
-		bio = bio_list_pop(&bios);
+static bool process_flush_bio(struct cache *cache, struct bio *bio)
+{
+	size_t pb_data_size = get_per_bio_data_size(cache);
+	struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size);
 
-		if (bio->bi_opf & REQ_PREFLUSH)
-			process_flush_bio(cache, bio);
-		else if (bio_op(bio) == REQ_OP_DISCARD)
-			process_discard_bio(cache, &structs, bio);
-		else
-			process_bio(cache, &structs, bio);
-	}
+	if (!pb->req_nr)
+		remap_to_origin(cache, bio);
+	else
+		remap_to_cache(cache, bio, 0);
 
-	if (prealloc_used)
-		prealloc_free_structs(cache, &structs);
+	issue_after_commit(&cache->committer, bio);
+	return true;
 }
 
-static void process_deferred_cells(struct cache *cache)
+static bool process_discard_bio(struct cache *cache, struct bio *bio)
 {
-	bool prealloc_used = false;
-	unsigned long flags;
-	struct dm_bio_prison_cell *cell, *tmp;
-	struct list_head cells;
-	struct prealloc structs;
-
-	memset(&structs, 0, sizeof(structs));
-
-	INIT_LIST_HEAD(&cells);
-
-	spin_lock_irqsave(&cache->lock, flags);
-	list_splice_init(&cache->deferred_cells, &cells);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	list_for_each_entry_safe(cell, tmp, &cells, user_list) {
-		/*
-		 * If we've got no free migration structs, and processing
-		 * this bio might require one, we pause until there are some
-		 * prepared mappings to process.
-		 */
-		prealloc_used = true;
-		if (prealloc_data_structs(cache, &structs)) {
-			spin_lock_irqsave(&cache->lock, flags);
-			list_splice(&cells, &cache->deferred_cells);
-			spin_unlock_irqrestore(&cache->lock, flags);
-			break;
-		}
+	dm_dblock_t b, e;
 
-		process_cell(cache, &structs, cell);
+	// FIXME: do we need to lock the region?  Or can we just assume the
+	// user wont be so foolish as to issue discard concurrently with
+	// other IO?
+	calc_discard_block_range(cache, bio, &b, &e);
+	while (b != e) {
+		set_discard(cache, b);
+		b = to_dblock(from_dblock(b) + 1);
 	}
 
-	if (prealloc_used)
-		prealloc_free_structs(cache, &structs);
+	bio_endio(bio);
+
+	return false;
 }
 
-static void process_deferred_flush_bios(struct cache *cache, bool submit_bios)
+static void process_deferred_bios(struct work_struct *ws)
 {
+	struct cache *cache = container_of(ws, struct cache, deferred_bio_worker);
+
 	unsigned long flags;
+	bool commit_needed = false;
 	struct bio_list bios;
 	struct bio *bio;
 
 	bio_list_init(&bios);
 
 	spin_lock_irqsave(&cache->lock, flags);
-	bio_list_merge(&bios, &cache->deferred_flush_bios);
-	bio_list_init(&cache->deferred_flush_bios);
+	bio_list_merge(&bios, &cache->deferred_bios);
+	bio_list_init(&cache->deferred_bios);
 	spin_unlock_irqrestore(&cache->lock, flags);
 
-	/*
-	 * These bios have already been through inc_ds()
-	 */
-	while ((bio = bio_list_pop(&bios)))
-		submit_bios ? accounted_request(cache, bio) : bio_io_error(bio);
+	while ((bio = bio_list_pop(&bios))) {
+		if (bio->bi_opf & REQ_PREFLUSH)
+			commit_needed = process_flush_bio(cache, bio) || commit_needed;
+
+		else if (bio_op(bio) == REQ_OP_DISCARD)
+			commit_needed = process_discard_bio(cache, bio) || commit_needed;
+
+		else
+			commit_needed = process_bio(cache, bio) || commit_needed;
+	}
+
+	if (commit_needed)
+		schedule_commit(&cache->committer);
 }
 
-static void process_deferred_writethrough_bios(struct cache *cache)
+static void process_deferred_writethrough_bios(struct work_struct *ws)
 {
+	struct cache *cache = container_of(ws, struct cache, deferred_writethrough_worker);
+
 	unsigned long flags;
 	struct bio_list bios;
 	struct bio *bio;
@@ -2058,153 +1997,15 @@ static void process_deferred_writethrough_bios(struct cache *cache)
 	spin_unlock_irqrestore(&cache->lock, flags);
 
 	/*
-	 * These bios have already been through inc_ds()
+	 * These bios have already been through accounted_begin()
 	 */
 	while ((bio = bio_list_pop(&bios)))
-		accounted_request(cache, bio);
-}
-
-static void writeback_some_dirty_blocks(struct cache *cache)
-{
-	bool prealloc_used = false;
-	dm_oblock_t oblock;
-	dm_cblock_t cblock;
-	struct prealloc structs;
-	struct dm_bio_prison_cell *old_ocell;
-	bool busy = !iot_idle_for(&cache->origin_tracker, HZ);
-
-	memset(&structs, 0, sizeof(structs));
-
-	while (spare_migration_bandwidth(cache)) {
-		if (policy_writeback_work(cache->policy, &oblock, &cblock, busy))
-			break; /* no work to do */
-
-		prealloc_used = true;
-		if (prealloc_data_structs(cache, &structs) ||
-		    get_cell(cache, oblock, &structs, &old_ocell)) {
-			policy_set_dirty(cache->policy, oblock);
-			break;
-		}
-
-		writeback(cache, &structs, oblock, cblock, old_ocell);
-	}
-
-	if (prealloc_used)
-		prealloc_free_structs(cache, &structs);
-}
-
-/*----------------------------------------------------------------
- * Invalidations.
- * Dropping something from the cache *without* writing back.
- *--------------------------------------------------------------*/
-
-static void process_invalidation_request(struct cache *cache, struct invalidation_request *req)
-{
-	int r = 0;
-	uint64_t begin = from_cblock(req->cblocks->begin);
-	uint64_t end = from_cblock(req->cblocks->end);
-
-	while (begin != end) {
-		r = policy_remove_cblock(cache->policy, to_cblock(begin));
-		if (!r) {
-			r = dm_cache_remove_mapping(cache->cmd, to_cblock(begin));
-			if (r) {
-				metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
-				break;
-			}
-
-		} else if (r == -ENODATA) {
-			/* harmless, already unmapped */
-			r = 0;
-
-		} else {
-			DMERR("%s: policy_remove_cblock failed", cache_device_name(cache));
-			break;
-		}
-
-		begin++;
-        }
-
-	cache->commit_requested = true;
-
-	req->err = r;
-	atomic_set(&req->complete, 1);
-
-	wake_up(&req->result_wait);
-}
-
-static void process_invalidation_requests(struct cache *cache)
-{
-	struct list_head list;
-	struct invalidation_request *req, *tmp;
-
-	INIT_LIST_HEAD(&list);
-	spin_lock(&cache->invalidation_lock);
-	list_splice_init(&cache->invalidation_requests, &list);
-	spin_unlock(&cache->invalidation_lock);
-
-	list_for_each_entry_safe (req, tmp, &list, list)
-		process_invalidation_request(cache, req);
+		generic_make_request(bio);
 }
 
 /*----------------------------------------------------------------
  * Main worker loop
  *--------------------------------------------------------------*/
-static bool is_quiescing(struct cache *cache)
-{
-	return atomic_read(&cache->quiescing);
-}
-
-static void ack_quiescing(struct cache *cache)
-{
-	if (is_quiescing(cache)) {
-		atomic_inc(&cache->quiescing_ack);
-		wake_up(&cache->quiescing_wait);
-	}
-}
-
-static void wait_for_quiescing_ack(struct cache *cache)
-{
-	wait_event(cache->quiescing_wait, atomic_read(&cache->quiescing_ack));
-}
-
-static void start_quiescing(struct cache *cache)
-{
-	atomic_inc(&cache->quiescing);
-	wait_for_quiescing_ack(cache);
-}
-
-static void stop_quiescing(struct cache *cache)
-{
-	atomic_set(&cache->quiescing, 0);
-	atomic_set(&cache->quiescing_ack, 0);
-}
-
-static void wait_for_migrations(struct cache *cache)
-{
-	wait_event(cache->migration_wait, !atomic_read(&cache->nr_allocated_migrations));
-}
-
-static void stop_worker(struct cache *cache)
-{
-	cancel_delayed_work(&cache->waker);
-	flush_workqueue(cache->wq);
-}
-
-static void requeue_deferred_cells(struct cache *cache)
-{
-	unsigned long flags;
-	struct list_head cells;
-	struct dm_bio_prison_cell *cell, *tmp;
-
-	INIT_LIST_HEAD(&cells);
-	spin_lock_irqsave(&cache->lock, flags);
-	list_splice_init(&cache->deferred_cells, &cells);
-	spin_unlock_irqrestore(&cache->lock, flags);
-
-	list_for_each_entry_safe(cell, tmp, &cells, user_list)
-		cell_requeue(cache, cell);
-}
 
 static void requeue_deferred_bios(struct cache *cache)
 {
@@ -2221,53 +2022,6 @@ static void requeue_deferred_bios(struct cache *cache)
 	}
 }
 
-static int more_work(struct cache *cache)
-{
-	if (is_quiescing(cache))
-		return !list_empty(&cache->quiesced_migrations) ||
-			!list_empty(&cache->completed_migrations) ||
-			!list_empty(&cache->need_commit_migrations);
-	else
-		return !bio_list_empty(&cache->deferred_bios) ||
-			!list_empty(&cache->deferred_cells) ||
-			!bio_list_empty(&cache->deferred_flush_bios) ||
-			!bio_list_empty(&cache->deferred_writethrough_bios) ||
-			!list_empty(&cache->quiesced_migrations) ||
-			!list_empty(&cache->completed_migrations) ||
-			!list_empty(&cache->need_commit_migrations) ||
-			cache->invalidate;
-}
-
-static void do_worker(struct work_struct *ws)
-{
-	struct cache *cache = container_of(ws, struct cache, worker);
-
-	do {
-		if (!is_quiescing(cache)) {
-			writeback_some_dirty_blocks(cache);
-			process_deferred_writethrough_bios(cache);
-			process_deferred_bios(cache);
-			process_deferred_cells(cache);
-			process_invalidation_requests(cache);
-		}
-
-		process_migrations(cache, &cache->quiesced_migrations, issue_copy_or_discard);
-		process_migrations(cache, &cache->completed_migrations, complete_migration);
-
-		if (commit_if_needed(cache)) {
-			process_deferred_flush_bios(cache, false);
-			process_migrations(cache, &cache->need_commit_migrations, migration_failure);
-		} else {
-			process_deferred_flush_bios(cache, true);
-			process_migrations(cache, &cache->need_commit_migrations,
-					   migration_success_post_commit);
-		}
-
-		ack_quiescing(cache);
-
-	} while (more_work(cache));
-}
-
 /*
  * We want to commit periodically so that not too much
  * unwritten metadata builds up.
@@ -2275,25 +2029,39 @@ static void do_worker(struct work_struct *ws)
 static void do_waker(struct work_struct *ws)
 {
 	struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker);
+
 	policy_tick(cache->policy, true);
-	wake_worker(cache);
+	wake_migration_worker(cache);
+	schedule_commit(&cache->committer);
 	queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD);
 }
 
-/*----------------------------------------------------------------*/
-
-static int is_congested(struct dm_dev *dev, int bdi_bits)
+static void check_migrations(struct work_struct *ws)
 {
-	struct request_queue *q = bdev_get_queue(dev->bdev);
-	return bdi_congested(q->backing_dev_info, bdi_bits);
-}
+	int r;
+	struct policy_work *op;
+	struct cache *cache = container_of(ws, struct cache, migration_worker);
+	enum busy b;
 
-static int cache_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
-{
-	struct cache *cache = container_of(cb, struct cache, callbacks);
+	for (;;) {
+		b = spare_migration_bandwidth(cache);
+		if (b == BUSY)
+			break;
 
-	return is_congested(cache->origin_dev, bdi_bits) ||
-		is_congested(cache->cache_dev, bdi_bits);
+		r = policy_get_background_work(cache->policy, b == IDLE, &op);
+		if (r == -ENODATA)
+			break;
+
+		if (r) {
+			DMERR_LIMIT("%s: policy_background_work failed",
+				    cache_device_name(cache));
+			break;
+		}
+
+		r = mg_start(cache, op, NULL);
+		if (r)
+			break;
+	}
 }
 
 /*----------------------------------------------------------------
@@ -2310,11 +2078,8 @@ static void destroy(struct cache *cache)
 
 	mempool_destroy(cache->migration_pool);
 
-	if (cache->all_io_ds)
-		dm_deferred_set_destroy(cache->all_io_ds);
-
 	if (cache->prison)
-		dm_bio_prison_destroy(cache->prison);
+		dm_bio_prison_destroy_v2(cache->prison);
 
 	if (cache->wq)
 		destroy_workqueue(cache->wq);
@@ -2707,6 +2472,7 @@ static int create_cache_policy(struct cache *cache, struct cache_args *ca,
 		return PTR_ERR(p);
 	}
 	cache->policy = p;
+	BUG_ON(!cache->policy);
 
 	return 0;
 }
@@ -2750,6 +2516,20 @@ static void set_cache_size(struct cache *cache, dm_cblock_t size)
 	cache->cache_size = size;
 }
 
+static int is_congested(struct dm_dev *dev, int bdi_bits)
+{
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+	return bdi_congested(q->backing_dev_info, bdi_bits);
+}
+
+static int cache_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
+{
+	struct cache *cache = container_of(cb, struct cache, callbacks);
+
+	return is_congested(cache->origin_dev, bdi_bits) ||
+		is_congested(cache->cache_dev, bdi_bits);
+}
+
 #define DEFAULT_MIGRATION_THRESHOLD 2048
 
 static int cache_create(struct cache_args *ca, struct cache **result)
@@ -2787,7 +2567,6 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 
 	ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL;
 
-	/* FIXME: factor out this whole section */
 	origin_blocks = cache->origin_sectors = ca->origin_sectors;
 	origin_blocks = block_div(origin_blocks, ca->block_size);
 	cache->origin_blocks = to_oblock(origin_blocks);
@@ -2853,24 +2632,18 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 			r = -EINVAL;
 			goto bad;
 		}
+
+		policy_allow_migrations(cache->policy, false);
 	}
 
 	spin_lock_init(&cache->lock);
 	INIT_LIST_HEAD(&cache->deferred_cells);
 	bio_list_init(&cache->deferred_bios);
-	bio_list_init(&cache->deferred_flush_bios);
 	bio_list_init(&cache->deferred_writethrough_bios);
-	INIT_LIST_HEAD(&cache->quiesced_migrations);
-	INIT_LIST_HEAD(&cache->completed_migrations);
-	INIT_LIST_HEAD(&cache->need_commit_migrations);
 	atomic_set(&cache->nr_allocated_migrations, 0);
 	atomic_set(&cache->nr_io_migrations, 0);
 	init_waitqueue_head(&cache->migration_wait);
 
-	init_waitqueue_head(&cache->quiescing_wait);
-	atomic_set(&cache->quiescing, 0);
-	atomic_set(&cache->quiescing_ack, 0);
-
 	r = -ENOMEM;
 	atomic_set(&cache->nr_dirty, 0);
 	cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size));
@@ -2899,27 +2672,23 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 		goto bad;
 	}
 
-	cache->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
+	cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0);
 	if (!cache->wq) {
 		*error = "could not create workqueue for metadata object";
 		goto bad;
 	}
-	INIT_WORK(&cache->worker, do_worker);
+	INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios);
+	INIT_WORK(&cache->deferred_writethrough_worker,
+		  process_deferred_writethrough_bios);
+	INIT_WORK(&cache->migration_worker, check_migrations);
 	INIT_DELAYED_WORK(&cache->waker, do_waker);
-	cache->last_commit_jiffies = jiffies;
 
-	cache->prison = dm_bio_prison_create();
+	cache->prison = dm_bio_prison_create_v2(cache->wq);
 	if (!cache->prison) {
 		*error = "could not create bio prison";
 		goto bad;
 	}
 
-	cache->all_io_ds = dm_deferred_set_create();
-	if (!cache->all_io_ds) {
-		*error = "could not create all_io deferred set";
-		goto bad;
-	}
-
 	cache->migration_pool = mempool_create_slab_pool(MIGRATION_POOL_SIZE,
 							 migration_cache);
 	if (!cache->migration_pool) {
@@ -2946,11 +2715,15 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 	spin_lock_init(&cache->invalidation_lock);
 	INIT_LIST_HEAD(&cache->invalidation_requests);
 
+	batcher_init(&cache->committer, commit_op, cache,
+		     issue_op, cache, cache->wq);
 	iot_init(&cache->origin_tracker);
 
+	init_rwsem(&cache->background_work_lock);
+	prevent_background_work(cache);
+
 	*result = cache;
 	return 0;
-
 bad:
 	destroy(cache);
 	return r;
@@ -3008,7 +2781,6 @@ static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	}
 
 	ti->private = cache;
-
 out:
 	destroy_cache_args(ca);
 	return r;
@@ -3021,17 +2793,11 @@ static int cache_map(struct dm_target *ti, struct bio *bio)
 	struct cache *cache = ti->private;
 
 	int r;
-	struct dm_bio_prison_cell *cell = NULL;
+	bool commit_needed;
 	dm_oblock_t block = get_bio_block(cache, bio);
 	size_t pb_data_size = get_per_bio_data_size(cache);
-	bool can_migrate = false;
-	bool fast_promotion;
-	struct policy_result lookup_result;
-	struct per_bio_data *pb = init_per_bio_data(bio, pb_data_size);
-	struct old_oblock_lock ool;
-
-	ool.locker.fn = null_locker;
 
+	init_per_bio_data(bio, pb_data_size);
 	if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) {
 		/*
 		 * This can only occur if the io goes to a partial block at
@@ -3048,101 +2814,9 @@ static int cache_map(struct dm_target *ti, struct bio *bio)
 		return DM_MAPIO_SUBMITTED;
 	}
 
-	/*
-	 * Check to see if that block is currently migrating.
-	 */
-	cell = alloc_prison_cell(cache);
-	if (!cell) {
-		defer_bio(cache, bio);
-		return DM_MAPIO_SUBMITTED;
-	}
-
-	r = bio_detain(cache, block, bio, cell,
-		       (cell_free_fn) free_prison_cell,
-		       cache, &cell);
-	if (r) {
-		if (r < 0)
-			defer_bio(cache, bio);
-
-		return DM_MAPIO_SUBMITTED;
-	}
-
-	fast_promotion = is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio);
-
-	r = policy_map(cache->policy, block, false, can_migrate, fast_promotion,
-		       bio, &ool.locker, &lookup_result);
-	if (r == -EWOULDBLOCK) {
-		cell_defer(cache, cell, true);
-		return DM_MAPIO_SUBMITTED;
-
-	} else if (r) {
-		DMERR_LIMIT("%s: Unexpected return from cache replacement policy: %d",
-			    cache_device_name(cache), r);
-		cell_defer(cache, cell, false);
-		bio_io_error(bio);
-		return DM_MAPIO_SUBMITTED;
-	}
-
-	r = DM_MAPIO_REMAPPED;
-	switch (lookup_result.op) {
-	case POLICY_HIT:
-		if (passthrough_mode(&cache->features)) {
-			if (bio_data_dir(bio) == WRITE) {
-				/*
-				 * We need to invalidate this block, so
-				 * defer for the worker thread.
-				 */
-				cell_defer(cache, cell, true);
-				r = DM_MAPIO_SUBMITTED;
-
-			} else {
-				inc_miss_counter(cache, bio);
-				remap_to_origin_clear_discard(cache, bio, block);
-				accounted_begin(cache, bio);
-				inc_ds(cache, bio, cell);
-				// FIXME: we want to remap hits or misses straight
-				// away rather than passing over to the worker.
-				cell_defer(cache, cell, false);
-			}
-
-		} else {
-			inc_hit_counter(cache, bio);
-			if (bio_data_dir(bio) == WRITE && writethrough_mode(&cache->features) &&
-			    !is_dirty(cache, lookup_result.cblock)) {
-				remap_to_origin_then_cache(cache, bio, block, lookup_result.cblock);
-				accounted_begin(cache, bio);
-				inc_ds(cache, bio, cell);
-				cell_defer(cache, cell, false);
-
-			} else
-				remap_cell_to_cache_dirty(cache, cell, block, lookup_result.cblock, false);
-		}
-		break;
-
-	case POLICY_MISS:
-		inc_miss_counter(cache, bio);
-		if (pb->req_nr != 0) {
-			/*
-			 * This is a duplicate writethrough io that is no
-			 * longer needed because the block has been demoted.
-			 */
-			bio_endio(bio);
-			// FIXME: remap everything as a miss
-			cell_defer(cache, cell, false);
-			r = DM_MAPIO_SUBMITTED;
-
-		} else
-			remap_cell_to_origin_clear_discard(cache, cell, block, false);
-		break;
-
-	default:
-		DMERR_LIMIT("%s: %s: erroring bio: unknown policy op: %u",
-			    cache_device_name(cache), __func__,
-			    (unsigned) lookup_result.op);
-		cell_defer(cache, cell, false);
-		bio_io_error(bio);
-		r = DM_MAPIO_SUBMITTED;
-	}
+	r = map_bio(cache, bio, block, &commit_needed);
+	if (commit_needed)
+		schedule_commit(&cache->committer);
 
 	return r;
 }
@@ -3162,7 +2836,7 @@ static int cache_end_io(struct dm_target *ti, struct bio *bio, int error)
 		spin_unlock_irqrestore(&cache->lock, flags);
 	}
 
-	check_for_quiesced_migrations(cache, pb);
+	bio_drop_shared_lock(cache, bio);
 	accounted_complete(cache, bio);
 
 	return 0;
@@ -3262,12 +2936,18 @@ static void cache_postsuspend(struct dm_target *ti)
 {
 	struct cache *cache = ti->private;
 
-	start_quiescing(cache);
-	wait_for_migrations(cache);
-	stop_worker(cache);
+	prevent_background_work(cache);
+	BUG_ON(atomic_read(&cache->nr_io_migrations));
+
+	cancel_delayed_work(&cache->waker);
+	flush_workqueue(cache->wq);
+	WARN_ON(cache->origin_tracker.in_flight);
+
+	/*
+	 * If it's a flush suspend there won't be any deferred bios, so this
+	 * call is harmless.
+	 */
 	requeue_deferred_bios(cache);
-	requeue_deferred_cells(cache);
-	stop_quiescing(cache);
 
 	if (get_cache_mode(cache) == CM_WRITE)
 		(void) sync_metadata(cache);
@@ -3279,15 +2959,16 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
 	int r;
 	struct cache *cache = context;
 
-	r = policy_load_mapping(cache->policy, oblock, cblock, hint, hint_valid);
+	if (dirty) {
+		set_bit(from_cblock(cblock), cache->dirty_bitset);
+		atomic_inc(&cache->nr_dirty);
+	} else
+		clear_bit(from_cblock(cblock), cache->dirty_bitset);
+
+	r = policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid);
 	if (r)
 		return r;
 
-	if (dirty)
-		set_dirty(cache, oblock, cblock);
-	else
-		clear_dirty(cache, oblock, cblock);
-
 	return 0;
 }
 
@@ -3486,6 +3167,7 @@ static void cache_resume(struct dm_target *ti)
 	struct cache *cache = ti->private;
 
 	cache->need_tick_bio = true;
+	allow_background_work(cache);
 	do_waker(&cache->waker.work);
 }
 
@@ -3620,10 +3302,19 @@ err:
 }
 
 /*
+ * Defines a range of cblocks, begin to (end - 1) are in the range.  end is
+ * the one-past-the-end value.
+ */
+struct cblock_range {
+	dm_cblock_t begin;
+	dm_cblock_t end;
+};
+
+/*
  * A cache block range can take two forms:
  *
  * i) A single cblock, eg. '3456'
- * ii) A begin and end cblock with dots between, eg. 123-234
+ * ii) A begin and end cblock with a dash between, eg. 123-234
  */
 static int parse_cblock_range(struct cache *cache, const char *str,
 			      struct cblock_range *result)
@@ -3689,23 +3380,31 @@ static int validate_cblock_range(struct cache *cache, struct cblock_range *range
 	return 0;
 }
 
+static inline dm_cblock_t cblock_succ(dm_cblock_t b)
+{
+	return to_cblock(from_cblock(b) + 1);
+}
+
 static int request_invalidation(struct cache *cache, struct cblock_range *range)
 {
-	struct invalidation_request req;
+	int r = 0;
 
-	INIT_LIST_HEAD(&req.list);
-	req.cblocks = range;
-	atomic_set(&req.complete, 0);
-	req.err = 0;
-	init_waitqueue_head(&req.result_wait);
+	/*
+	 * We don't need to do any locking here because we know we're in
+	 * passthrough mode.  There's is potential for a race between an
+	 * invalidation triggered by an io and an invalidation message.  This
+	 * is harmless, we must not worry if the policy call fails.
+	 */
+	while (range->begin != range->end) {
+		r = invalidate_cblock(cache, range->begin);
+		if (r)
+			return r;
 
-	spin_lock(&cache->invalidation_lock);
-	list_add(&req.list, &cache->invalidation_requests);
-	spin_unlock(&cache->invalidation_lock);
-	wake_worker(cache);
+		range->begin = cblock_succ(range->begin);
+	}
 
-	wait_event(req.result_wait, atomic_read(&req.complete));
-	return req.err;
+	cache->commit_requested = true;
+	return r;
 }
 
 static int process_invalidate_cblocks_message(struct cache *cache, unsigned count,
@@ -3815,7 +3514,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type cache_target = {
 	.name = "cache",
-	.version = {1, 10, 0},
+	.version = {2, 0, 0},
 	.module = THIS_MODULE,
 	.ctr = cache_ctr,
 	.dtr = cache_dtr,
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index fea5bd52ada8..97db4d11c05a 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -47,7 +47,7 @@ struct mapped_device {
 	struct request_queue *queue;
 	int numa_node_id;
 
-	unsigned type;
+	enum dm_queue_mode type;
 	/* Protect queue and type against concurrent access. */
 	struct mutex type_lock;
 
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ef1d836bd81b..ebf9e72d479b 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1,8 +1,8 @@
 /*
  * Copyright (C) 2003 Jana Saout <jana@saout.de>
  * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
- * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved.
- * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
+ * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com>
  *
  * This file is released under the GPL.
  */
@@ -31,6 +31,9 @@
 #include <crypto/md5.h>
 #include <crypto/algapi.h>
 #include <crypto/skcipher.h>
+#include <crypto/aead.h>
+#include <crypto/authenc.h>
+#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
 #include <keys/user-type.h>
 
 #include <linux/device-mapper.h>
@@ -48,7 +51,11 @@ struct convert_context {
 	struct bvec_iter iter_out;
 	sector_t cc_sector;
 	atomic_t cc_pending;
-	struct skcipher_request *req;
+	union {
+		struct skcipher_request *req;
+		struct aead_request *req_aead;
+	} r;
+
 };
 
 /*
@@ -57,6 +64,8 @@ struct convert_context {
 struct dm_crypt_io {
 	struct crypt_config *cc;
 	struct bio *base_bio;
+	u8 *integrity_metadata;
+	bool integrity_metadata_from_pool;
 	struct work_struct work;
 
 	struct convert_context ctx;
@@ -70,8 +79,8 @@ struct dm_crypt_io {
 
 struct dm_crypt_request {
 	struct convert_context *ctx;
-	struct scatterlist sg_in;
-	struct scatterlist sg_out;
+	struct scatterlist sg_in[4];
+	struct scatterlist sg_out[4];
 	sector_t iv_sector;
 };
 
@@ -118,6 +127,11 @@ struct iv_tcw_private {
 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
 	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
 
+enum cipher_flags {
+	CRYPT_MODE_INTEGRITY_AEAD,	/* Use authenticated mode for cihper */
+	CRYPT_IV_LARGE_SECTORS,		/* Calculate IV from sector_size, not 512B sectors */
+};
+
 /*
  * The fields in here must be read only after initialization.
  */
@@ -126,11 +140,14 @@ struct crypt_config {
 	sector_t start;
 
 	/*
-	 * pool for per bio private data, crypto requests and
-	 * encryption requeusts/buffer pages
+	 * pool for per bio private data, crypto requests,
+	 * encryption requeusts/buffer pages and integrity tags
 	 */
 	mempool_t *req_pool;
 	mempool_t *page_pool;
+	mempool_t *tag_pool;
+	unsigned tag_pool_max_sectors;
+
 	struct bio_set *bs;
 	struct mutex bio_alloc_lock;
 
@@ -143,6 +160,7 @@ struct crypt_config {
 
 	char *cipher;
 	char *cipher_string;
+	char *cipher_auth;
 	char *key_string;
 
 	const struct crypt_iv_operations *iv_gen_ops;
@@ -154,11 +172,17 @@ struct crypt_config {
 	} iv_gen_private;
 	sector_t iv_offset;
 	unsigned int iv_size;
+	unsigned short int sector_size;
+	unsigned char sector_shift;
 
 	/* ESSIV: struct crypto_cipher *essiv_tfm */
 	void *iv_private;
-	struct crypto_skcipher **tfms;
+	union {
+		struct crypto_skcipher **tfms;
+		struct crypto_aead **tfms_aead;
+	} cipher_tfm;
 	unsigned tfms_count;
+	unsigned long cipher_flags;
 
 	/*
 	 * Layout of each crypto request:
@@ -181,21 +205,36 @@ struct crypt_config {
 	unsigned int key_size;
 	unsigned int key_parts;      /* independent parts in key buffer */
 	unsigned int key_extra_size; /* additional keys length */
+	unsigned int key_mac_size;   /* MAC key size for authenc(...) */
+
+	unsigned int integrity_tag_size;
+	unsigned int integrity_iv_size;
+	unsigned int on_disk_tag_size;
+
+	u8 *authenc_key; /* space for keys in authenc() format (if used) */
 	u8 key[0];
 };
 
-#define MIN_IOS        64
+#define MIN_IOS		64
+#define MAX_TAG_SIZE	480
+#define POOL_ENTRY_SIZE	512
 
 static void clone_init(struct dm_crypt_io *, struct bio *);
 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
-static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
+static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
+					     struct scatterlist *sg);
 
 /*
- * Use this to access cipher attributes that are the same for each CPU.
+ * Use this to access cipher attributes that are independent of the key.
  */
 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 {
-	return cc->tfms[0];
+	return cc->cipher_tfm.tfms[0];
+}
+
+static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
+{
+	return cc->cipher_tfm.tfms_aead[0];
 }
 
 /*
@@ -310,10 +349,11 @@ static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 	return err;
 }
 
-/* Set up per cpu cipher state */
-static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
-					     struct dm_target *ti,
-					     u8 *salt, unsigned saltsize)
+/* Allocate the cipher for ESSIV */
+static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
+						struct dm_target *ti,
+						const u8 *salt,
+						unsigned int saltsize)
 {
 	struct crypto_cipher *essiv_tfm;
 	int err;
@@ -325,8 +365,7 @@ static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
 		return essiv_tfm;
 	}
 
-	if (crypto_cipher_blocksize(essiv_tfm) !=
-	    crypto_skcipher_ivsize(any_tfm(cc))) {
+	if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) {
 		ti->error = "Block size of ESSIV cipher does "
 			    "not match IV size of block cipher";
 		crypto_free_cipher(essiv_tfm);
@@ -393,8 +432,8 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 	cc->iv_gen_private.essiv.salt = salt;
 	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 
-	essiv_tfm = setup_essiv_cpu(cc, ti, salt,
-				crypto_ahash_digestsize(hash_tfm));
+	essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
+				       crypto_ahash_digestsize(hash_tfm));
 	if (IS_ERR(essiv_tfm)) {
 		crypt_iv_essiv_dtr(cc);
 		return PTR_ERR(essiv_tfm);
@@ -488,6 +527,11 @@ static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
 {
 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 
+	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
+		ti->error = "Unsupported sector size for LMK";
+		return -EINVAL;
+	}
+
 	lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
 	if (IS_ERR(lmk->hash_tfm)) {
 		ti->error = "Error initializing LMK hash";
@@ -585,12 +629,14 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 			    struct dm_crypt_request *dmreq)
 {
+	struct scatterlist *sg;
 	u8 *src;
 	int r = 0;
 
 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
-		src = kmap_atomic(sg_page(&dmreq->sg_in));
-		r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
+		sg = crypt_get_sg_data(cc, dmreq->sg_in);
+		src = kmap_atomic(sg_page(sg));
+		r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
 		kunmap_atomic(src);
 	} else
 		memset(iv, 0, cc->iv_size);
@@ -601,18 +647,20 @@ static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 			     struct dm_crypt_request *dmreq)
 {
+	struct scatterlist *sg;
 	u8 *dst;
 	int r;
 
 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
 		return 0;
 
-	dst = kmap_atomic(sg_page(&dmreq->sg_out));
-	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
+	sg = crypt_get_sg_data(cc, dmreq->sg_out);
+	dst = kmap_atomic(sg_page(sg));
+	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
 
 	/* Tweak the first block of plaintext sector */
 	if (!r)
-		crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
+		crypto_xor(dst + sg->offset, iv, cc->iv_size);
 
 	kunmap_atomic(dst);
 	return r;
@@ -637,6 +685,11 @@ static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
 {
 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 
+	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
+		ti->error = "Unsupported sector size for TCW";
+		return -EINVAL;
+	}
+
 	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
 		ti->error = "Wrong key size for TCW";
 		return -EINVAL;
@@ -724,6 +777,7 @@ out:
 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 			    struct dm_crypt_request *dmreq)
 {
+	struct scatterlist *sg;
 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 	__le64 sector = cpu_to_le64(dmreq->iv_sector);
 	u8 *src;
@@ -731,8 +785,9 @@ static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 
 	/* Remove whitening from ciphertext */
 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
-		src = kmap_atomic(sg_page(&dmreq->sg_in));
-		r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
+		sg = crypt_get_sg_data(cc, dmreq->sg_in);
+		src = kmap_atomic(sg_page(sg));
+		r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
 		kunmap_atomic(src);
 	}
 
@@ -748,6 +803,7 @@ static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 			     struct dm_crypt_request *dmreq)
 {
+	struct scatterlist *sg;
 	u8 *dst;
 	int r;
 
@@ -755,13 +811,22 @@ static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 		return 0;
 
 	/* Apply whitening on ciphertext */
-	dst = kmap_atomic(sg_page(&dmreq->sg_out));
-	r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
+	sg = crypt_get_sg_data(cc, dmreq->sg_out);
+	dst = kmap_atomic(sg_page(sg));
+	r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
 	kunmap_atomic(dst);
 
 	return r;
 }
 
+static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
+				struct dm_crypt_request *dmreq)
+{
+	/* Used only for writes, there must be an additional space to store IV */
+	get_random_bytes(iv, cc->iv_size);
+	return 0;
+}
+
 static const struct crypt_iv_operations crypt_iv_plain_ops = {
 	.generator = crypt_iv_plain_gen
 };
@@ -806,6 +871,108 @@ static const struct crypt_iv_operations crypt_iv_tcw_ops = {
 	.post	   = crypt_iv_tcw_post
 };
 
+static struct crypt_iv_operations crypt_iv_random_ops = {
+	.generator = crypt_iv_random_gen
+};
+
+/*
+ * Integrity extensions
+ */
+static bool crypt_integrity_aead(struct crypt_config *cc)
+{
+	return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
+}
+
+static bool crypt_integrity_hmac(struct crypt_config *cc)
+{
+	return crypt_integrity_aead(cc) && cc->key_mac_size;
+}
+
+/* Get sg containing data */
+static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
+					     struct scatterlist *sg)
+{
+	if (unlikely(crypt_integrity_aead(cc)))
+		return &sg[2];
+
+	return sg;
+}
+
+static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
+{
+	struct bio_integrity_payload *bip;
+	unsigned int tag_len;
+	int ret;
+
+	if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
+		return 0;
+
+	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
+	if (IS_ERR(bip))
+		return PTR_ERR(bip);
+
+	tag_len = io->cc->on_disk_tag_size * bio_sectors(bio);
+
+	bip->bip_iter.bi_size = tag_len;
+	bip->bip_iter.bi_sector = io->cc->start + io->sector;
+
+	/* We own the metadata, do not let bio_free to release it */
+	bip->bip_flags &= ~BIP_BLOCK_INTEGRITY;
+
+	ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
+				     tag_len, offset_in_page(io->integrity_metadata));
+	if (unlikely(ret != tag_len))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
+{
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+	struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
+
+	/* From now we require underlying device with our integrity profile */
+	if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
+		ti->error = "Integrity profile not supported.";
+		return -EINVAL;
+	}
+
+	if (bi->tag_size != cc->on_disk_tag_size ||
+	    bi->tuple_size != cc->on_disk_tag_size) {
+		ti->error = "Integrity profile tag size mismatch.";
+		return -EINVAL;
+	}
+	if (1 << bi->interval_exp != cc->sector_size) {
+		ti->error = "Integrity profile sector size mismatch.";
+		return -EINVAL;
+	}
+
+	if (crypt_integrity_aead(cc)) {
+		cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
+		DMINFO("Integrity AEAD, tag size %u, IV size %u.",
+		       cc->integrity_tag_size, cc->integrity_iv_size);
+
+		if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
+			ti->error = "Integrity AEAD auth tag size is not supported.";
+			return -EINVAL;
+		}
+	} else if (cc->integrity_iv_size)
+		DMINFO("Additional per-sector space %u bytes for IV.",
+		       cc->integrity_iv_size);
+
+	if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
+		ti->error = "Not enough space for integrity tag in the profile.";
+		return -EINVAL;
+	}
+
+	return 0;
+#else
+	ti->error = "Integrity profile not supported.";
+	return -EINVAL;
+#endif
+}
+
 static void crypt_convert_init(struct crypt_config *cc,
 			       struct convert_context *ctx,
 			       struct bio *bio_out, struct bio *bio_in,
@@ -822,58 +989,217 @@ static void crypt_convert_init(struct crypt_config *cc,
 }
 
 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
-					     struct skcipher_request *req)
+					     void *req)
 {
 	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
 }
 
-static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
-					       struct dm_crypt_request *dmreq)
+static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
 {
-	return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
+	return (void *)((char *)dmreq - cc->dmreq_start);
 }
 
 static u8 *iv_of_dmreq(struct crypt_config *cc,
 		       struct dm_crypt_request *dmreq)
 {
-	return (u8 *)ALIGN((unsigned long)(dmreq + 1),
-		crypto_skcipher_alignmask(any_tfm(cc)) + 1);
+	if (crypt_integrity_aead(cc))
+		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
+			crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
+	else
+		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
+			crypto_skcipher_alignmask(any_tfm(cc)) + 1);
 }
 
-static int crypt_convert_block(struct crypt_config *cc,
-			       struct convert_context *ctx,
-			       struct skcipher_request *req)
+static u8 *org_iv_of_dmreq(struct crypt_config *cc,
+		       struct dm_crypt_request *dmreq)
+{
+	return iv_of_dmreq(cc, dmreq) + cc->iv_size;
+}
+
+static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
+		       struct dm_crypt_request *dmreq)
+{
+	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
+	return (uint64_t*) ptr;
+}
+
+static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
+		       struct dm_crypt_request *dmreq)
+{
+	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
+		  cc->iv_size + sizeof(uint64_t);
+	return (unsigned int*)ptr;
+}
+
+static void *tag_from_dmreq(struct crypt_config *cc,
+				struct dm_crypt_request *dmreq)
+{
+	struct convert_context *ctx = dmreq->ctx;
+	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
+
+	return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
+		cc->on_disk_tag_size];
+}
+
+static void *iv_tag_from_dmreq(struct crypt_config *cc,
+			       struct dm_crypt_request *dmreq)
+{
+	return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
+}
+
+static int crypt_convert_block_aead(struct crypt_config *cc,
+				     struct convert_context *ctx,
+				     struct aead_request *req,
+				     unsigned int tag_offset)
 {
 	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
 	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
 	struct dm_crypt_request *dmreq;
-	u8 *iv;
-	int r;
+	u8 *iv, *org_iv, *tag_iv, *tag;
+	uint64_t *sector;
+	int r = 0;
+
+	BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
+
+	/* Reject unexpected unaligned bio. */
+	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
+		return -EIO;
 
 	dmreq = dmreq_of_req(cc, req);
+	dmreq->iv_sector = ctx->cc_sector;
+	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
+		dmreq->iv_sector >>= cc->sector_shift;
+	dmreq->ctx = ctx;
+
+	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
+
+	sector = org_sector_of_dmreq(cc, dmreq);
+	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
+
 	iv = iv_of_dmreq(cc, dmreq);
+	org_iv = org_iv_of_dmreq(cc, dmreq);
+	tag = tag_from_dmreq(cc, dmreq);
+	tag_iv = iv_tag_from_dmreq(cc, dmreq);
+
+	/* AEAD request:
+	 *  |----- AAD -------|------ DATA -------|-- AUTH TAG --|
+	 *  | (authenticated) | (auth+encryption) |              |
+	 *  | sector_LE |  IV |  sector in/out    |  tag in/out  |
+	 */
+	sg_init_table(dmreq->sg_in, 4);
+	sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
+	sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
+	sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
+	sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
+
+	sg_init_table(dmreq->sg_out, 4);
+	sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
+	sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
+	sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
+	sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
+
+	if (cc->iv_gen_ops) {
+		/* For READs use IV stored in integrity metadata */
+		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
+			memcpy(org_iv, tag_iv, cc->iv_size);
+		} else {
+			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
+			if (r < 0)
+				return r;
+			/* Store generated IV in integrity metadata */
+			if (cc->integrity_iv_size)
+				memcpy(tag_iv, org_iv, cc->iv_size);
+		}
+		/* Working copy of IV, to be modified in crypto API */
+		memcpy(iv, org_iv, cc->iv_size);
+	}
+
+	aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
+	if (bio_data_dir(ctx->bio_in) == WRITE) {
+		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
+				       cc->sector_size, iv);
+		r = crypto_aead_encrypt(req);
+		if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
+			memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
+			       cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
+	} else {
+		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
+				       cc->sector_size + cc->integrity_tag_size, iv);
+		r = crypto_aead_decrypt(req);
+	}
+
+	if (r == -EBADMSG)
+		DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
+			    (unsigned long long)le64_to_cpu(*sector));
+
+	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
+		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
+
+	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
+	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
+
+	return r;
+}
+
+static int crypt_convert_block_skcipher(struct crypt_config *cc,
+					struct convert_context *ctx,
+					struct skcipher_request *req,
+					unsigned int tag_offset)
+{
+	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
+	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
+	struct scatterlist *sg_in, *sg_out;
+	struct dm_crypt_request *dmreq;
+	u8 *iv, *org_iv, *tag_iv;
+	uint64_t *sector;
+	int r = 0;
 
+	/* Reject unexpected unaligned bio. */
+	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
+		return -EIO;
+
+	dmreq = dmreq_of_req(cc, req);
 	dmreq->iv_sector = ctx->cc_sector;
+	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
+		dmreq->iv_sector >>= cc->sector_shift;
 	dmreq->ctx = ctx;
-	sg_init_table(&dmreq->sg_in, 1);
-	sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
-		    bv_in.bv_offset);
 
-	sg_init_table(&dmreq->sg_out, 1);
-	sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
-		    bv_out.bv_offset);
+	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
+
+	iv = iv_of_dmreq(cc, dmreq);
+	org_iv = org_iv_of_dmreq(cc, dmreq);
+	tag_iv = iv_tag_from_dmreq(cc, dmreq);
+
+	sector = org_sector_of_dmreq(cc, dmreq);
+	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
+
+	/* For skcipher we use only the first sg item */
+	sg_in  = &dmreq->sg_in[0];
+	sg_out = &dmreq->sg_out[0];
 
-	bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
-	bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
+	sg_init_table(sg_in, 1);
+	sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
+
+	sg_init_table(sg_out, 1);
+	sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
 
 	if (cc->iv_gen_ops) {
-		r = cc->iv_gen_ops->generator(cc, iv, dmreq);
-		if (r < 0)
-			return r;
+		/* For READs use IV stored in integrity metadata */
+		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
+			memcpy(org_iv, tag_iv, cc->integrity_iv_size);
+		} else {
+			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
+			if (r < 0)
+				return r;
+			/* Store generated IV in integrity metadata */
+			if (cc->integrity_iv_size)
+				memcpy(tag_iv, org_iv, cc->integrity_iv_size);
+		}
+		/* Working copy of IV, to be modified in crypto API */
+		memcpy(iv, org_iv, cc->iv_size);
 	}
 
-	skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
-				   1 << SECTOR_SHIFT, iv);
+	skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
 
 	if (bio_data_dir(ctx->bio_in) == WRITE)
 		r = crypto_skcipher_encrypt(req);
@@ -881,7 +1207,10 @@ static int crypt_convert_block(struct crypt_config *cc,
 		r = crypto_skcipher_decrypt(req);
 
 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
-		r = cc->iv_gen_ops->post(cc, iv, dmreq);
+		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
+
+	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
+	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
 
 	return r;
 }
@@ -889,27 +1218,53 @@ static int crypt_convert_block(struct crypt_config *cc,
 static void kcryptd_async_done(struct crypto_async_request *async_req,
 			       int error);
 
-static void crypt_alloc_req(struct crypt_config *cc,
-			    struct convert_context *ctx)
+static void crypt_alloc_req_skcipher(struct crypt_config *cc,
+				     struct convert_context *ctx)
 {
 	unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
 
-	if (!ctx->req)
-		ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
+	if (!ctx->r.req)
+		ctx->r.req = mempool_alloc(cc->req_pool, GFP_NOIO);
 
-	skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
+	skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
 
 	/*
 	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
 	 * requests if driver request queue is full.
 	 */
-	skcipher_request_set_callback(ctx->req,
+	skcipher_request_set_callback(ctx->r.req,
 	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-	    kcryptd_async_done, dmreq_of_req(cc, ctx->req));
+	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
 }
 
-static void crypt_free_req(struct crypt_config *cc,
-			   struct skcipher_request *req, struct bio *base_bio)
+static void crypt_alloc_req_aead(struct crypt_config *cc,
+				 struct convert_context *ctx)
+{
+	if (!ctx->r.req_aead)
+		ctx->r.req_aead = mempool_alloc(cc->req_pool, GFP_NOIO);
+
+	aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
+
+	/*
+	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
+	 * requests if driver request queue is full.
+	 */
+	aead_request_set_callback(ctx->r.req_aead,
+	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
+	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
+}
+
+static void crypt_alloc_req(struct crypt_config *cc,
+			    struct convert_context *ctx)
+{
+	if (crypt_integrity_aead(cc))
+		crypt_alloc_req_aead(cc, ctx);
+	else
+		crypt_alloc_req_skcipher(cc, ctx);
+}
+
+static void crypt_free_req_skcipher(struct crypt_config *cc,
+				    struct skcipher_request *req, struct bio *base_bio)
 {
 	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
 
@@ -917,12 +1272,31 @@ static void crypt_free_req(struct crypt_config *cc,
 		mempool_free(req, cc->req_pool);
 }
 
+static void crypt_free_req_aead(struct crypt_config *cc,
+				struct aead_request *req, struct bio *base_bio)
+{
+	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
+
+	if ((struct aead_request *)(io + 1) != req)
+		mempool_free(req, cc->req_pool);
+}
+
+static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
+{
+	if (crypt_integrity_aead(cc))
+		crypt_free_req_aead(cc, req, base_bio);
+	else
+		crypt_free_req_skcipher(cc, req, base_bio);
+}
+
 /*
  * Encrypt / decrypt data from one bio to another one (can be the same one)
  */
 static int crypt_convert(struct crypt_config *cc,
 			 struct convert_context *ctx)
 {
+	unsigned int tag_offset = 0;
+	unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
 	int r;
 
 	atomic_set(&ctx->cc_pending, 1);
@@ -930,10 +1304,12 @@ static int crypt_convert(struct crypt_config *cc,
 	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
 
 		crypt_alloc_req(cc, ctx);
-
 		atomic_inc(&ctx->cc_pending);
 
-		r = crypt_convert_block(cc, ctx, ctx->req);
+		if (crypt_integrity_aead(cc))
+			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
+		else
+			r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
 
 		switch (r) {
 		/*
@@ -949,22 +1325,31 @@ static int crypt_convert(struct crypt_config *cc,
 		 * completion function kcryptd_async_done() will be called.
 		 */
 		case -EINPROGRESS:
-			ctx->req = NULL;
-			ctx->cc_sector++;
+			ctx->r.req = NULL;
+			ctx->cc_sector += sector_step;
+			tag_offset++;
 			continue;
 		/*
 		 * The request was already processed (synchronously).
 		 */
 		case 0:
 			atomic_dec(&ctx->cc_pending);
-			ctx->cc_sector++;
+			ctx->cc_sector += sector_step;
+			tag_offset++;
 			cond_resched();
 			continue;
-
-		/* There was an error while processing the request. */
+		/*
+		 * There was a data integrity error.
+		 */
+		case -EBADMSG:
+			atomic_dec(&ctx->cc_pending);
+			return -EILSEQ;
+		/*
+		 * There was an error while processing the request.
+		 */
 		default:
 			atomic_dec(&ctx->cc_pending);
-			return r;
+			return -EIO;
 		}
 	}
 
@@ -1005,7 +1390,7 @@ retry:
 
 	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
 	if (!clone)
-		goto return_clone;
+		goto out;
 
 	clone_init(io, clone);
 
@@ -1027,7 +1412,13 @@ retry:
 		remaining_size -= len;
 	}
 
-return_clone:
+	/* Allocate space for integrity tags */
+	if (dm_crypt_integrity_io_alloc(io, clone)) {
+		crypt_free_buffer_pages(cc, clone);
+		bio_put(clone);
+		clone = NULL;
+	}
+out:
 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
 		mutex_unlock(&cc->bio_alloc_lock);
 
@@ -1053,7 +1444,9 @@ static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
 	io->base_bio = bio;
 	io->sector = sector;
 	io->error = 0;
-	io->ctx.req = NULL;
+	io->ctx.r.req = NULL;
+	io->integrity_metadata = NULL;
+	io->integrity_metadata_from_pool = false;
 	atomic_set(&io->io_pending, 0);
 }
 
@@ -1075,8 +1468,13 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 	if (!atomic_dec_and_test(&io->io_pending))
 		return;
 
-	if (io->ctx.req)
-		crypt_free_req(cc, io->ctx.req, base_bio);
+	if (io->ctx.r.req)
+		crypt_free_req(cc, io->ctx.r.req, base_bio);
+
+	if (unlikely(io->integrity_metadata_from_pool))
+		mempool_free(io->integrity_metadata, io->cc->tag_pool);
+	else
+		kfree(io->integrity_metadata);
 
 	base_bio->bi_error = error;
 	bio_endio(base_bio);
@@ -1156,6 +1554,12 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 	clone_init(io, clone);
 	clone->bi_iter.bi_sector = cc->start + io->sector;
 
+	if (dm_crypt_integrity_io_alloc(io, clone)) {
+		crypt_dec_pending(io);
+		bio_put(clone);
+		return 1;
+	}
+
 	generic_make_request(clone);
 	return 0;
 }
@@ -1314,8 +1718,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 
 	crypt_inc_pending(io);
 	r = crypt_convert(cc, &io->ctx);
-	if (r)
-		io->error = -EIO;
+	if (r < 0)
+		io->error = r;
 	crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
 
 	/* Encryption was already finished, submit io now */
@@ -1345,7 +1749,7 @@ static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
 
 	r = crypt_convert(cc, &io->ctx);
 	if (r < 0)
-		io->error = -EIO;
+		io->error = r;
 
 	if (atomic_dec_and_test(&io->ctx.cc_pending))
 		kcryptd_crypt_read_done(io);
@@ -1372,9 +1776,13 @@ static void kcryptd_async_done(struct crypto_async_request *async_req,
 	}
 
 	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
-		error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
+		error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
 
-	if (error < 0)
+	if (error == -EBADMSG) {
+		DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
+			    (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
+		io->error = -EILSEQ;
+	} else if (error < 0)
 		io->error = -EIO;
 
 	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
@@ -1406,61 +1814,59 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io)
 	queue_work(cc->crypt_queue, &io->work);
 }
 
-/*
- * Decode key from its hex representation
- */
-static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
+static void crypt_free_tfms_aead(struct crypt_config *cc)
 {
-	char buffer[3];
-	unsigned int i;
-
-	buffer[2] = '\0';
-
-	for (i = 0; i < size; i++) {
-		buffer[0] = *hex++;
-		buffer[1] = *hex++;
+	if (!cc->cipher_tfm.tfms_aead)
+		return;
 
-		if (kstrtou8(buffer, 16, &key[i]))
-			return -EINVAL;
+	if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
+		crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
+		cc->cipher_tfm.tfms_aead[0] = NULL;
 	}
 
-	if (*hex != '\0')
-		return -EINVAL;
-
-	return 0;
+	kfree(cc->cipher_tfm.tfms_aead);
+	cc->cipher_tfm.tfms_aead = NULL;
 }
 
-static void crypt_free_tfms(struct crypt_config *cc)
+static void crypt_free_tfms_skcipher(struct crypt_config *cc)
 {
 	unsigned i;
 
-	if (!cc->tfms)
+	if (!cc->cipher_tfm.tfms)
 		return;
 
 	for (i = 0; i < cc->tfms_count; i++)
-		if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
-			crypto_free_skcipher(cc->tfms[i]);
-			cc->tfms[i] = NULL;
+		if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
+			crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
+			cc->cipher_tfm.tfms[i] = NULL;
 		}
 
-	kfree(cc->tfms);
-	cc->tfms = NULL;
+	kfree(cc->cipher_tfm.tfms);
+	cc->cipher_tfm.tfms = NULL;
 }
 
-static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
+static void crypt_free_tfms(struct crypt_config *cc)
+{
+	if (crypt_integrity_aead(cc))
+		crypt_free_tfms_aead(cc);
+	else
+		crypt_free_tfms_skcipher(cc);
+}
+
+static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
 {
 	unsigned i;
 	int err;
 
-	cc->tfms = kzalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
-			   GFP_KERNEL);
-	if (!cc->tfms)
+	cc->cipher_tfm.tfms = kzalloc(cc->tfms_count *
+				      sizeof(struct crypto_skcipher *), GFP_KERNEL);
+	if (!cc->cipher_tfm.tfms)
 		return -ENOMEM;
 
 	for (i = 0; i < cc->tfms_count; i++) {
-		cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
-		if (IS_ERR(cc->tfms[i])) {
-			err = PTR_ERR(cc->tfms[i]);
+		cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
+		if (IS_ERR(cc->cipher_tfm.tfms[i])) {
+			err = PTR_ERR(cc->cipher_tfm.tfms[i]);
 			crypt_free_tfms(cc);
 			return err;
 		}
@@ -1469,22 +1875,95 @@ static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
 	return 0;
 }
 
+static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
+{
+	int err;
+
+	cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
+	if (!cc->cipher_tfm.tfms)
+		return -ENOMEM;
+
+	cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
+	if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
+		err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
+		crypt_free_tfms(cc);
+		return err;
+	}
+
+	return 0;
+}
+
+static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
+{
+	if (crypt_integrity_aead(cc))
+		return crypt_alloc_tfms_aead(cc, ciphermode);
+	else
+		return crypt_alloc_tfms_skcipher(cc, ciphermode);
+}
+
+static unsigned crypt_subkey_size(struct crypt_config *cc)
+{
+	return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
+}
+
+static unsigned crypt_authenckey_size(struct crypt_config *cc)
+{
+	return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
+}
+
+/*
+ * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
+ * the key must be for some reason in special format.
+ * This funcion converts cc->key to this special format.
+ */
+static void crypt_copy_authenckey(char *p, const void *key,
+				  unsigned enckeylen, unsigned authkeylen)
+{
+	struct crypto_authenc_key_param *param;
+	struct rtattr *rta;
+
+	rta = (struct rtattr *)p;
+	param = RTA_DATA(rta);
+	param->enckeylen = cpu_to_be32(enckeylen);
+	rta->rta_len = RTA_LENGTH(sizeof(*param));
+	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
+	p += RTA_SPACE(sizeof(*param));
+	memcpy(p, key + enckeylen, authkeylen);
+	p += authkeylen;
+	memcpy(p, key, enckeylen);
+}
+
 static int crypt_setkey(struct crypt_config *cc)
 {
 	unsigned subkey_size;
 	int err = 0, i, r;
 
 	/* Ignore extra keys (which are used for IV etc) */
-	subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
+	subkey_size = crypt_subkey_size(cc);
 
+	if (crypt_integrity_hmac(cc))
+		crypt_copy_authenckey(cc->authenc_key, cc->key,
+				      subkey_size - cc->key_mac_size,
+				      cc->key_mac_size);
 	for (i = 0; i < cc->tfms_count; i++) {
-		r = crypto_skcipher_setkey(cc->tfms[i],
-					   cc->key + (i * subkey_size),
-					   subkey_size);
+		if (crypt_integrity_hmac(cc))
+			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
+				cc->authenc_key, crypt_authenckey_size(cc));
+		else if (crypt_integrity_aead(cc))
+			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
+					       cc->key + (i * subkey_size),
+					       subkey_size);
+		else
+			r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
+						   cc->key + (i * subkey_size),
+						   subkey_size);
 		if (r)
 			err = r;
 	}
 
+	if (crypt_integrity_hmac(cc))
+		memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
+
 	return err;
 }
 
@@ -1633,7 +2112,8 @@ static int crypt_set_key(struct crypt_config *cc, char *key)
 	kzfree(cc->key_string);
 	cc->key_string = NULL;
 
-	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
+	/* Decode key from its hex representation. */
+	if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
 		goto out;
 
 	r = crypt_setkey(cc);
@@ -1649,12 +2129,16 @@ out:
 
 static int crypt_wipe_key(struct crypt_config *cc)
 {
+	int r;
+
 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
-	memset(&cc->key, 0, cc->key_size * sizeof(u8));
+	get_random_bytes(&cc->key, cc->key_size);
 	kzfree(cc->key_string);
 	cc->key_string = NULL;
+	r = crypt_setkey(cc);
+	memset(&cc->key, 0, cc->key_size * sizeof(u8));
 
-	return crypt_setkey(cc);
+	return r;
 }
 
 static void crypt_dtr(struct dm_target *ti)
@@ -1681,6 +2165,7 @@ static void crypt_dtr(struct dm_target *ti)
 
 	mempool_destroy(cc->page_pool);
 	mempool_destroy(cc->req_pool);
+	mempool_destroy(cc->tag_pool);
 
 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
 		cc->iv_gen_ops->dtr(cc);
@@ -1691,30 +2176,221 @@ static void crypt_dtr(struct dm_target *ti)
 	kzfree(cc->cipher);
 	kzfree(cc->cipher_string);
 	kzfree(cc->key_string);
+	kzfree(cc->cipher_auth);
+	kzfree(cc->authenc_key);
 
 	/* Must zero key material before freeing */
 	kzfree(cc);
 }
 
-static int crypt_ctr_cipher(struct dm_target *ti,
-			    char *cipher_in, char *key)
+static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
+{
+	struct crypt_config *cc = ti->private;
+
+	if (crypt_integrity_aead(cc))
+		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
+	else
+		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
+
+	if (cc->iv_size)
+		/* at least a 64 bit sector number should fit in our buffer */
+		cc->iv_size = max(cc->iv_size,
+				  (unsigned int)(sizeof(u64) / sizeof(u8)));
+	else if (ivmode) {
+		DMWARN("Selected cipher does not support IVs");
+		ivmode = NULL;
+	}
+
+	/* Choose ivmode, see comments at iv code. */
+	if (ivmode == NULL)
+		cc->iv_gen_ops = NULL;
+	else if (strcmp(ivmode, "plain") == 0)
+		cc->iv_gen_ops = &crypt_iv_plain_ops;
+	else if (strcmp(ivmode, "plain64") == 0)
+		cc->iv_gen_ops = &crypt_iv_plain64_ops;
+	else if (strcmp(ivmode, "essiv") == 0)
+		cc->iv_gen_ops = &crypt_iv_essiv_ops;
+	else if (strcmp(ivmode, "benbi") == 0)
+		cc->iv_gen_ops = &crypt_iv_benbi_ops;
+	else if (strcmp(ivmode, "null") == 0)
+		cc->iv_gen_ops = &crypt_iv_null_ops;
+	else if (strcmp(ivmode, "lmk") == 0) {
+		cc->iv_gen_ops = &crypt_iv_lmk_ops;
+		/*
+		 * Version 2 and 3 is recognised according
+		 * to length of provided multi-key string.
+		 * If present (version 3), last key is used as IV seed.
+		 * All keys (including IV seed) are always the same size.
+		 */
+		if (cc->key_size % cc->key_parts) {
+			cc->key_parts++;
+			cc->key_extra_size = cc->key_size / cc->key_parts;
+		}
+	} else if (strcmp(ivmode, "tcw") == 0) {
+		cc->iv_gen_ops = &crypt_iv_tcw_ops;
+		cc->key_parts += 2; /* IV + whitening */
+		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
+	} else if (strcmp(ivmode, "random") == 0) {
+		cc->iv_gen_ops = &crypt_iv_random_ops;
+		/* Need storage space in integrity fields. */
+		cc->integrity_iv_size = cc->iv_size;
+	} else {
+		ti->error = "Invalid IV mode";
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Workaround to parse cipher algorithm from crypto API spec.
+ * The cc->cipher is currently used only in ESSIV.
+ * This should be probably done by crypto-api calls (once available...)
+ */
+static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
+{
+	const char *alg_name = NULL;
+	char *start, *end;
+
+	if (crypt_integrity_aead(cc)) {
+		alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
+		if (!alg_name)
+			return -EINVAL;
+		if (crypt_integrity_hmac(cc)) {
+			alg_name = strchr(alg_name, ',');
+			if (!alg_name)
+				return -EINVAL;
+		}
+		alg_name++;
+	} else {
+		alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
+		if (!alg_name)
+			return -EINVAL;
+	}
+
+	start = strchr(alg_name, '(');
+	end = strchr(alg_name, ')');
+
+	if (!start && !end) {
+		cc->cipher = kstrdup(alg_name, GFP_KERNEL);
+		return cc->cipher ? 0 : -ENOMEM;
+	}
+
+	if (!start || !end || ++start >= end)
+		return -EINVAL;
+
+	cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
+	if (!cc->cipher)
+		return -ENOMEM;
+
+	strncpy(cc->cipher, start, end - start);
+
+	return 0;
+}
+
+/*
+ * Workaround to parse HMAC algorithm from AEAD crypto API spec.
+ * The HMAC is needed to calculate tag size (HMAC digest size).
+ * This should be probably done by crypto-api calls (once available...)
+ */
+static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
+{
+	char *start, *end, *mac_alg = NULL;
+	struct crypto_ahash *mac;
+
+	if (!strstarts(cipher_api, "authenc("))
+		return 0;
+
+	start = strchr(cipher_api, '(');
+	end = strchr(cipher_api, ',');
+	if (!start || !end || ++start > end)
+		return -EINVAL;
+
+	mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
+	if (!mac_alg)
+		return -ENOMEM;
+	strncpy(mac_alg, start, end - start);
+
+	mac = crypto_alloc_ahash(mac_alg, 0, 0);
+	kfree(mac_alg);
+
+	if (IS_ERR(mac))
+		return PTR_ERR(mac);
+
+	cc->key_mac_size = crypto_ahash_digestsize(mac);
+	crypto_free_ahash(mac);
+
+	cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
+	if (!cc->authenc_key)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
+				char **ivmode, char **ivopts)
+{
+	struct crypt_config *cc = ti->private;
+	char *tmp, *cipher_api;
+	int ret = -EINVAL;
+
+	cc->tfms_count = 1;
+
+	/*
+	 * New format (capi: prefix)
+	 * capi:cipher_api_spec-iv:ivopts
+	 */
+	tmp = &cipher_in[strlen("capi:")];
+	cipher_api = strsep(&tmp, "-");
+	*ivmode = strsep(&tmp, ":");
+	*ivopts = tmp;
+
+	if (*ivmode && !strcmp(*ivmode, "lmk"))
+		cc->tfms_count = 64;
+
+	cc->key_parts = cc->tfms_count;
+
+	/* Allocate cipher */
+	ret = crypt_alloc_tfms(cc, cipher_api);
+	if (ret < 0) {
+		ti->error = "Error allocating crypto tfm";
+		return ret;
+	}
+
+	/* Alloc AEAD, can be used only in new format. */
+	if (crypt_integrity_aead(cc)) {
+		ret = crypt_ctr_auth_cipher(cc, cipher_api);
+		if (ret < 0) {
+			ti->error = "Invalid AEAD cipher spec";
+			return -ENOMEM;
+		}
+		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
+	} else
+		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
+
+	ret = crypt_ctr_blkdev_cipher(cc);
+	if (ret < 0) {
+		ti->error = "Cannot allocate cipher string";
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
+				char **ivmode, char **ivopts)
 {
 	struct crypt_config *cc = ti->private;
-	char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
+	char *tmp, *cipher, *chainmode, *keycount;
 	char *cipher_api = NULL;
 	int ret = -EINVAL;
 	char dummy;
 
-	/* Convert to crypto api definition? */
-	if (strchr(cipher_in, '(')) {
+	if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
 		ti->error = "Bad cipher specification";
 		return -EINVAL;
 	}
 
-	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
-	if (!cc->cipher_string)
-		goto bad_mem;
-
 	/*
 	 * Legacy dm-crypt cipher specification
 	 * cipher[:keycount]-mode-iv:ivopts
@@ -1731,15 +2407,14 @@ static int crypt_ctr_cipher(struct dm_target *ti,
 		return -EINVAL;
 	}
 	cc->key_parts = cc->tfms_count;
-	cc->key_extra_size = 0;
 
 	cc->cipher = kstrdup(cipher, GFP_KERNEL);
 	if (!cc->cipher)
 		goto bad_mem;
 
 	chainmode = strsep(&tmp, "-");
-	ivopts = strsep(&tmp, "-");
-	ivmode = strsep(&ivopts, ":");
+	*ivopts = strsep(&tmp, "-");
+	*ivmode = strsep(&*ivopts, ":");
 
 	if (tmp)
 		DMWARN("Ignoring unexpected additional cipher options");
@@ -1748,12 +2423,12 @@ static int crypt_ctr_cipher(struct dm_target *ti,
 	 * For compatibility with the original dm-crypt mapping format, if
 	 * only the cipher name is supplied, use cbc-plain.
 	 */
-	if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
+	if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
 		chainmode = "cbc";
-		ivmode = "plain";
+		*ivmode = "plain";
 	}
 
-	if (strcmp(chainmode, "ecb") && !ivmode) {
+	if (strcmp(chainmode, "ecb") && !*ivmode) {
 		ti->error = "IV mechanism required";
 		return -EINVAL;
 	}
@@ -1773,60 +2448,45 @@ static int crypt_ctr_cipher(struct dm_target *ti,
 	ret = crypt_alloc_tfms(cc, cipher_api);
 	if (ret < 0) {
 		ti->error = "Error allocating crypto tfm";
-		goto bad;
+		kfree(cipher_api);
+		return ret;
 	}
 
-	/* Initialize IV */
-	cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
-	if (cc->iv_size)
-		/* at least a 64 bit sector number should fit in our buffer */
-		cc->iv_size = max(cc->iv_size,
-				  (unsigned int)(sizeof(u64) / sizeof(u8)));
-	else if (ivmode) {
-		DMWARN("Selected cipher does not support IVs");
-		ivmode = NULL;
-	}
+	return 0;
+bad_mem:
+	ti->error = "Cannot allocate cipher strings";
+	return -ENOMEM;
+}
 
-	/* Choose ivmode, see comments at iv code. */
-	if (ivmode == NULL)
-		cc->iv_gen_ops = NULL;
-	else if (strcmp(ivmode, "plain") == 0)
-		cc->iv_gen_ops = &crypt_iv_plain_ops;
-	else if (strcmp(ivmode, "plain64") == 0)
-		cc->iv_gen_ops = &crypt_iv_plain64_ops;
-	else if (strcmp(ivmode, "essiv") == 0)
-		cc->iv_gen_ops = &crypt_iv_essiv_ops;
-	else if (strcmp(ivmode, "benbi") == 0)
-		cc->iv_gen_ops = &crypt_iv_benbi_ops;
-	else if (strcmp(ivmode, "null") == 0)
-		cc->iv_gen_ops = &crypt_iv_null_ops;
-	else if (strcmp(ivmode, "lmk") == 0) {
-		cc->iv_gen_ops = &crypt_iv_lmk_ops;
-		/*
-		 * Version 2 and 3 is recognised according
-		 * to length of provided multi-key string.
-		 * If present (version 3), last key is used as IV seed.
-		 * All keys (including IV seed) are always the same size.
-		 */
-		if (cc->key_size % cc->key_parts) {
-			cc->key_parts++;
-			cc->key_extra_size = cc->key_size / cc->key_parts;
-		}
-	} else if (strcmp(ivmode, "tcw") == 0) {
-		cc->iv_gen_ops = &crypt_iv_tcw_ops;
-		cc->key_parts += 2; /* IV + whitening */
-		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
-	} else {
-		ret = -EINVAL;
-		ti->error = "Invalid IV mode";
-		goto bad;
+static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
+{
+	struct crypt_config *cc = ti->private;
+	char *ivmode = NULL, *ivopts = NULL;
+	int ret;
+
+	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
+	if (!cc->cipher_string) {
+		ti->error = "Cannot allocate cipher strings";
+		return -ENOMEM;
 	}
 
+	if (strstarts(cipher_in, "capi:"))
+		ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
+	else
+		ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
+	if (ret)
+		return ret;
+
+	/* Initialize IV */
+	ret = crypt_ctr_ivmode(ti, ivmode);
+	if (ret < 0)
+		return ret;
+
 	/* Initialize and set key */
 	ret = crypt_set_key(cc, key);
 	if (ret < 0) {
 		ti->error = "Error decoding and setting key";
-		goto bad;
+		return ret;
 	}
 
 	/* Allocate IV */
@@ -1834,7 +2494,7 @@ static int crypt_ctr_cipher(struct dm_target *ti,
 		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
 		if (ret < 0) {
 			ti->error = "Error creating IV";
-			goto bad;
+			return ret;
 		}
 	}
 
@@ -1843,18 +2503,82 @@ static int crypt_ctr_cipher(struct dm_target *ti,
 		ret = cc->iv_gen_ops->init(cc);
 		if (ret < 0) {
 			ti->error = "Error initialising IV";
-			goto bad;
+			return ret;
 		}
 	}
 
-	ret = 0;
-bad:
-	kfree(cipher_api);
 	return ret;
+}
 
-bad_mem:
-	ti->error = "Cannot allocate cipher strings";
-	return -ENOMEM;
+static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
+{
+	struct crypt_config *cc = ti->private;
+	struct dm_arg_set as;
+	static struct dm_arg _args[] = {
+		{0, 6, "Invalid number of feature args"},
+	};
+	unsigned int opt_params, val;
+	const char *opt_string, *sval;
+	char dummy;
+	int ret;
+
+	/* Optional parameters */
+	as.argc = argc;
+	as.argv = argv;
+
+	ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
+	if (ret)
+		return ret;
+
+	while (opt_params--) {
+		opt_string = dm_shift_arg(&as);
+		if (!opt_string) {
+			ti->error = "Not enough feature arguments";
+			return -EINVAL;
+		}
+
+		if (!strcasecmp(opt_string, "allow_discards"))
+			ti->num_discard_bios = 1;
+
+		else if (!strcasecmp(opt_string, "same_cpu_crypt"))
+			set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
+
+		else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
+			set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
+		else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
+			if (val == 0 || val > MAX_TAG_SIZE) {
+				ti->error = "Invalid integrity arguments";
+				return -EINVAL;
+			}
+			cc->on_disk_tag_size = val;
+			sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
+			if (!strcasecmp(sval, "aead")) {
+				set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
+			} else  if (strcasecmp(sval, "none")) {
+				ti->error = "Unknown integrity profile";
+				return -EINVAL;
+			}
+
+			cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
+			if (!cc->cipher_auth)
+				return -ENOMEM;
+		} else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
+			if (cc->sector_size < (1 << SECTOR_SHIFT) ||
+			    cc->sector_size > 4096 ||
+			    (cc->sector_size & (cc->sector_size - 1))) {
+				ti->error = "Invalid feature value for sector_size";
+				return -EINVAL;
+			}
+			cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
+		} else if (!strcasecmp(opt_string, "iv_large_sectors"))
+			set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
+		else {
+			ti->error = "Invalid feature arguments";
+			return -EINVAL;
+		}
+	}
+
+	return 0;
 }
 
 /*
@@ -1865,18 +2589,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct crypt_config *cc;
 	int key_size;
-	unsigned int opt_params;
+	unsigned int align_mask;
 	unsigned long long tmpll;
 	int ret;
-	size_t iv_size_padding;
-	struct dm_arg_set as;
-	const char *opt_string;
+	size_t iv_size_padding, additional_req_size;
 	char dummy;
 
-	static struct dm_arg _args[] = {
-		{0, 3, "Invalid number of feature args"},
-	};
-
 	if (argc < 5) {
 		ti->error = "Not enough arguments";
 		return -EINVAL;
@@ -1894,40 +2612,63 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -ENOMEM;
 	}
 	cc->key_size = key_size;
+	cc->sector_size = (1 << SECTOR_SHIFT);
+	cc->sector_shift = 0;
 
 	ti->private = cc;
+
+	/* Optional parameters need to be read before cipher constructor */
+	if (argc > 5) {
+		ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
+		if (ret)
+			goto bad;
+	}
+
 	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
 	if (ret < 0)
 		goto bad;
 
-	cc->dmreq_start = sizeof(struct skcipher_request);
-	cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
+	if (crypt_integrity_aead(cc)) {
+		cc->dmreq_start = sizeof(struct aead_request);
+		cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
+		align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
+	} else {
+		cc->dmreq_start = sizeof(struct skcipher_request);
+		cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
+		align_mask = crypto_skcipher_alignmask(any_tfm(cc));
+	}
 	cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
 
-	if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
+	if (align_mask < CRYPTO_MINALIGN) {
 		/* Allocate the padding exactly */
 		iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
-				& crypto_skcipher_alignmask(any_tfm(cc));
+				& align_mask;
 	} else {
 		/*
 		 * If the cipher requires greater alignment than kmalloc
 		 * alignment, we don't know the exact position of the
 		 * initialization vector. We must assume worst case.
 		 */
-		iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
+		iv_size_padding = align_mask;
 	}
 
 	ret = -ENOMEM;
-	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
-			sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
+
+	/*  ...| IV + padding | original IV | original sec. number | bio tag offset | */
+	additional_req_size = sizeof(struct dm_crypt_request) +
+		iv_size_padding + cc->iv_size +
+		cc->iv_size +
+		sizeof(uint64_t) +
+		sizeof(unsigned int);
+
+	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + additional_req_size);
 	if (!cc->req_pool) {
 		ti->error = "Cannot allocate crypt request mempool";
 		goto bad;
 	}
 
 	cc->per_bio_data_size = ti->per_io_data_size =
-		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
-		      sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
+		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
 		      ARCH_KMALLOC_MINALIGN);
 
 	cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
@@ -1945,7 +2686,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	mutex_init(&cc->bio_alloc_lock);
 
 	ret = -EINVAL;
-	if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
+	if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
+	    (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
 		ti->error = "Invalid iv_offset sector";
 		goto bad;
 	}
@@ -1964,53 +2706,37 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 	cc->start = tmpll;
 
-	argv += 5;
-	argc -= 5;
-
-	/* Optional parameters */
-	if (argc) {
-		as.argc = argc;
-		as.argv = argv;
-
-		ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
+	if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
+		ret = crypt_integrity_ctr(cc, ti);
 		if (ret)
 			goto bad;
 
-		ret = -EINVAL;
-		while (opt_params--) {
-			opt_string = dm_shift_arg(&as);
-			if (!opt_string) {
-				ti->error = "Not enough feature arguments";
-				goto bad;
-			}
-
-			if (!strcasecmp(opt_string, "allow_discards"))
-				ti->num_discard_bios = 1;
+		cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
+		if (!cc->tag_pool_max_sectors)
+			cc->tag_pool_max_sectors = 1;
 
-			else if (!strcasecmp(opt_string, "same_cpu_crypt"))
-				set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
-
-			else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
-				set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
-
-			else {
-				ti->error = "Invalid feature arguments";
-				goto bad;
-			}
+		cc->tag_pool = mempool_create_kmalloc_pool(MIN_IOS,
+			cc->tag_pool_max_sectors * cc->on_disk_tag_size);
+		if (!cc->tag_pool) {
+			ti->error = "Cannot allocate integrity tags mempool";
+			goto bad;
 		}
+
+		cc->tag_pool_max_sectors <<= cc->sector_shift;
 	}
 
 	ret = -ENOMEM;
-	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
+	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
 	if (!cc->io_queue) {
 		ti->error = "Couldn't create kcryptd io queue";
 		goto bad;
 	}
 
 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
-		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
+		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
 	else
-		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
+		cc->crypt_queue = alloc_workqueue("kcryptd",
+						  WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
 						  num_online_cpus());
 	if (!cc->crypt_queue) {
 		ti->error = "Couldn't create kcryptd queue";
@@ -2061,12 +2787,39 @@ static int crypt_map(struct dm_target *ti, struct bio *bio)
 	 * Check if bio is too large, split as needed.
 	 */
 	if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
-	    bio_data_dir(bio) == WRITE)
+	    (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
 		dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
 
+	/*
+	 * Ensure that bio is a multiple of internal sector encryption size
+	 * and is aligned to this size as defined in IO hints.
+	 */
+	if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
+		return -EIO;
+
+	if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
+		return -EIO;
+
 	io = dm_per_bio_data(bio, cc->per_bio_data_size);
 	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
-	io->ctx.req = (struct skcipher_request *)(io + 1);
+
+	if (cc->on_disk_tag_size) {
+		unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
+
+		if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
+		    unlikely(!(io->integrity_metadata = kmalloc(tag_len,
+				GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
+			if (bio_sectors(bio) > cc->tag_pool_max_sectors)
+				dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
+			io->integrity_metadata = mempool_alloc(cc->tag_pool, GFP_NOIO);
+			io->integrity_metadata_from_pool = true;
+		}
+	}
+
+	if (crypt_integrity_aead(cc))
+		io->ctx.r.req_aead = (struct aead_request *)(io + 1);
+	else
+		io->ctx.r.req = (struct skcipher_request *)(io + 1);
 
 	if (bio_data_dir(io->base_bio) == READ) {
 		if (kcryptd_io_read(io, GFP_NOWAIT))
@@ -2107,6 +2860,10 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 		num_feature_args += !!ti->num_discard_bios;
 		num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
 		num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
+		num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
+		num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
+		if (cc->on_disk_tag_size)
+			num_feature_args++;
 		if (num_feature_args) {
 			DMEMIT(" %d", num_feature_args);
 			if (ti->num_discard_bios)
@@ -2115,6 +2872,12 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 				DMEMIT(" same_cpu_crypt");
 			if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
 				DMEMIT(" submit_from_crypt_cpus");
+			if (cc->on_disk_tag_size)
+				DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
+			if (cc->sector_size != (1 << SECTOR_SHIFT))
+				DMEMIT(" sector_size:%d", cc->sector_size);
+			if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
+				DMEMIT(" iv_large_sectors");
 		}
 
 		break;
@@ -2204,6 +2967,8 @@ static int crypt_iterate_devices(struct dm_target *ti,
 
 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
+	struct crypt_config *cc = ti->private;
+
 	/*
 	 * Unfortunate constraint that is required to avoid the potential
 	 * for exceeding underlying device's max_segments limits -- due to
@@ -2211,11 +2976,17 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 	 * bio that are not as physically contiguous as the original bio.
 	 */
 	limits->max_segment_size = PAGE_SIZE;
+
+	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
+		limits->logical_block_size = cc->sector_size;
+		limits->physical_block_size = cc->sector_size;
+		blk_limits_io_min(limits, cc->sector_size);
+	}
 }
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version = {1, 15, 0},
+	.version = {1, 17, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index cc70871a6d29..ae3158795d26 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -340,6 +340,7 @@ out:
 static struct target_type delay_target = {
 	.name	     = "delay",
 	.version     = {1, 2, 1},
+	.features    = DM_TARGET_PASSES_INTEGRITY,
 	.module      = THIS_MODULE,
 	.ctr	     = delay_ctr,
 	.dtr	     = delay_dtr,
diff --git a/drivers/md/dm-era-target.c b/drivers/md/dm-era-target.c
index 9fab33b113c4..e7ba89f98d8d 100644
--- a/drivers/md/dm-era-target.c
+++ b/drivers/md/dm-era-target.c
@@ -254,7 +254,6 @@ static struct dm_block_validator sb_validator = {
  * Low level metadata handling
  *--------------------------------------------------------------*/
 #define DM_ERA_METADATA_BLOCK_SIZE 4096
-#define DM_ERA_METADATA_CACHE_SIZE 64
 #define ERA_MAX_CONCURRENT_LOCKS 5
 
 struct era_metadata {
@@ -615,7 +614,6 @@ static int create_persistent_data_objects(struct era_metadata *md,
 	int r;
 
 	md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE,
-					 DM_ERA_METADATA_CACHE_SIZE,
 					 ERA_MAX_CONCURRENT_LOCKS);
 	if (IS_ERR(md->bm)) {
 		DMERR("could not create block manager");
@@ -961,15 +959,15 @@ static int metadata_commit(struct era_metadata *md)
 		}
 	}
 
-	r = save_sm_root(md);
+	r = dm_tm_pre_commit(md->tm);
 	if (r) {
-		DMERR("%s: save_sm_root failed", __func__);
+		DMERR("%s: pre commit failed", __func__);
 		return r;
 	}
 
-	r = dm_tm_pre_commit(md->tm);
+	r = save_sm_root(md);
 	if (r) {
-		DMERR("%s: pre commit failed", __func__);
+		DMERR("%s: save_sm_root failed", __func__);
 		return r;
 	}
 
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
new file mode 100644
index 000000000000..c7f7c8d76576
--- /dev/null
+++ b/drivers/md/dm-integrity.c
@@ -0,0 +1,3238 @@
+/*
+ * Copyright (C) 2016-2017 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2016-2017 Milan Broz
+ * Copyright (C) 2016-2017 Mikulas Patocka
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/module.h>
+#include <linux/device-mapper.h>
+#include <linux/dm-io.h>
+#include <linux/vmalloc.h>
+#include <linux/sort.h>
+#include <linux/rbtree.h>
+#include <linux/delay.h>
+#include <linux/random.h>
+#include <crypto/hash.h>
+#include <crypto/skcipher.h>
+#include <linux/async_tx.h>
+#include "dm-bufio.h"
+
+#define DM_MSG_PREFIX "integrity"
+
+#define DEFAULT_INTERLEAVE_SECTORS	32768
+#define DEFAULT_JOURNAL_SIZE_FACTOR	7
+#define DEFAULT_BUFFER_SECTORS		128
+#define DEFAULT_JOURNAL_WATERMARK	50
+#define DEFAULT_SYNC_MSEC		10000
+#define DEFAULT_MAX_JOURNAL_SECTORS	131072
+#define MIN_LOG2_INTERLEAVE_SECTORS	3
+#define MAX_LOG2_INTERLEAVE_SECTORS	31
+#define METADATA_WORKQUEUE_MAX_ACTIVE	16
+
+/*
+ * Warning - DEBUG_PRINT prints security-sensitive data to the log,
+ * so it should not be enabled in the official kernel
+ */
+//#define DEBUG_PRINT
+//#define INTERNAL_VERIFY
+
+/*
+ * On disk structures
+ */
+
+#define SB_MAGIC			"integrt"
+#define SB_VERSION			1
+#define SB_SECTORS			8
+#define MAX_SECTORS_PER_BLOCK		8
+
+struct superblock {
+	__u8 magic[8];
+	__u8 version;
+	__u8 log2_interleave_sectors;
+	__u16 integrity_tag_size;
+	__u32 journal_sections;
+	__u64 provided_data_sectors;	/* userspace uses this value */
+	__u32 flags;
+	__u8 log2_sectors_per_block;
+};
+
+#define SB_FLAG_HAVE_JOURNAL_MAC	0x1
+
+#define	JOURNAL_ENTRY_ROUNDUP		8
+
+typedef __u64 commit_id_t;
+#define JOURNAL_MAC_PER_SECTOR		8
+
+struct journal_entry {
+	union {
+		struct {
+			__u32 sector_lo;
+			__u32 sector_hi;
+		} s;
+		__u64 sector;
+	} u;
+	commit_id_t last_bytes[0];
+	/* __u8 tag[0]; */
+};
+
+#define journal_entry_tag(ic, je)		((__u8 *)&(je)->last_bytes[(ic)->sectors_per_block])
+
+#if BITS_PER_LONG == 64
+#define journal_entry_set_sector(je, x)		do { smp_wmb(); ACCESS_ONCE((je)->u.sector) = cpu_to_le64(x); } while (0)
+#define journal_entry_get_sector(je)		le64_to_cpu((je)->u.sector)
+#elif defined(CONFIG_LBDAF)
+#define journal_entry_set_sector(je, x)		do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32((x) >> 32); } while (0)
+#define journal_entry_get_sector(je)		le64_to_cpu((je)->u.sector)
+#else
+#define journal_entry_set_sector(je, x)		do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); ACCESS_ONCE((je)->u.s.sector_hi) = cpu_to_le32(0); } while (0)
+#define journal_entry_get_sector(je)		le32_to_cpu((je)->u.s.sector_lo)
+#endif
+#define journal_entry_is_unused(je)		((je)->u.s.sector_hi == cpu_to_le32(-1))
+#define journal_entry_set_unused(je)		do { ((je)->u.s.sector_hi = cpu_to_le32(-1)); } while (0)
+#define journal_entry_is_inprogress(je)		((je)->u.s.sector_hi == cpu_to_le32(-2))
+#define journal_entry_set_inprogress(je)	do { ((je)->u.s.sector_hi = cpu_to_le32(-2)); } while (0)
+
+#define JOURNAL_BLOCK_SECTORS		8
+#define JOURNAL_SECTOR_DATA		((1 << SECTOR_SHIFT) - sizeof(commit_id_t))
+#define JOURNAL_MAC_SIZE		(JOURNAL_MAC_PER_SECTOR * JOURNAL_BLOCK_SECTORS)
+
+struct journal_sector {
+	__u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
+	__u8 mac[JOURNAL_MAC_PER_SECTOR];
+	commit_id_t commit_id;
+};
+
+#define MAX_TAG_SIZE			(JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR - offsetof(struct journal_entry, last_bytes[MAX_SECTORS_PER_BLOCK]))
+
+#define METADATA_PADDING_SECTORS	8
+
+#define N_COMMIT_IDS			4
+
+static unsigned char prev_commit_seq(unsigned char seq)
+{
+	return (seq + N_COMMIT_IDS - 1) % N_COMMIT_IDS;
+}
+
+static unsigned char next_commit_seq(unsigned char seq)
+{
+	return (seq + 1) % N_COMMIT_IDS;
+}
+
+/*
+ * In-memory structures
+ */
+
+struct journal_node {
+	struct rb_node node;
+	sector_t sector;
+};
+
+struct alg_spec {
+	char *alg_string;
+	char *key_string;
+	__u8 *key;
+	unsigned key_size;
+};
+
+struct dm_integrity_c {
+	struct dm_dev *dev;
+	unsigned tag_size;
+	__s8 log2_tag_size;
+	sector_t start;
+	mempool_t *journal_io_mempool;
+	struct dm_io_client *io;
+	struct dm_bufio_client *bufio;
+	struct workqueue_struct *metadata_wq;
+	struct superblock *sb;
+	unsigned journal_pages;
+	struct page_list *journal;
+	struct page_list *journal_io;
+	struct page_list *journal_xor;
+
+	struct crypto_skcipher *journal_crypt;
+	struct scatterlist **journal_scatterlist;
+	struct scatterlist **journal_io_scatterlist;
+	struct skcipher_request **sk_requests;
+
+	struct crypto_shash *journal_mac;
+
+	struct journal_node *journal_tree;
+	struct rb_root journal_tree_root;
+
+	sector_t provided_data_sectors;
+
+	unsigned short journal_entry_size;
+	unsigned char journal_entries_per_sector;
+	unsigned char journal_section_entries;
+	unsigned short journal_section_sectors;
+	unsigned journal_sections;
+	unsigned journal_entries;
+	sector_t device_sectors;
+	unsigned initial_sectors;
+	unsigned metadata_run;
+	__s8 log2_metadata_run;
+	__u8 log2_buffer_sectors;
+	__u8 sectors_per_block;
+
+	unsigned char mode;
+	bool suspending;
+
+	int failed;
+
+	struct crypto_shash *internal_hash;
+
+	/* these variables are locked with endio_wait.lock */
+	struct rb_root in_progress;
+	wait_queue_head_t endio_wait;
+	struct workqueue_struct *wait_wq;
+
+	unsigned char commit_seq;
+	commit_id_t commit_ids[N_COMMIT_IDS];
+
+	unsigned committed_section;
+	unsigned n_committed_sections;
+
+	unsigned uncommitted_section;
+	unsigned n_uncommitted_sections;
+
+	unsigned free_section;
+	unsigned char free_section_entry;
+	unsigned free_sectors;
+
+	unsigned free_sectors_threshold;
+
+	struct workqueue_struct *commit_wq;
+	struct work_struct commit_work;
+
+	struct workqueue_struct *writer_wq;
+	struct work_struct writer_work;
+
+	struct bio_list flush_bio_list;
+
+	unsigned long autocommit_jiffies;
+	struct timer_list autocommit_timer;
+	unsigned autocommit_msec;
+
+	wait_queue_head_t copy_to_journal_wait;
+
+	struct completion crypto_backoff;
+
+	bool journal_uptodate;
+	bool just_formatted;
+
+	struct alg_spec internal_hash_alg;
+	struct alg_spec journal_crypt_alg;
+	struct alg_spec journal_mac_alg;
+};
+
+struct dm_integrity_range {
+	sector_t logical_sector;
+	unsigned n_sectors;
+	struct rb_node node;
+};
+
+struct dm_integrity_io {
+	struct work_struct work;
+
+	struct dm_integrity_c *ic;
+	bool write;
+	bool fua;
+
+	struct dm_integrity_range range;
+
+	sector_t metadata_block;
+	unsigned metadata_offset;
+
+	atomic_t in_flight;
+	int bi_error;
+
+	struct completion *completion;
+
+	struct block_device *orig_bi_bdev;
+	bio_end_io_t *orig_bi_end_io;
+	struct bio_integrity_payload *orig_bi_integrity;
+	struct bvec_iter orig_bi_iter;
+};
+
+struct journal_completion {
+	struct dm_integrity_c *ic;
+	atomic_t in_flight;
+	struct completion comp;
+};
+
+struct journal_io {
+	struct dm_integrity_range range;
+	struct journal_completion *comp;
+};
+
+static struct kmem_cache *journal_io_cache;
+
+#define JOURNAL_IO_MEMPOOL	32
+
+#ifdef DEBUG_PRINT
+#define DEBUG_print(x, ...)	printk(KERN_DEBUG x, ##__VA_ARGS__)
+static void __DEBUG_bytes(__u8 *bytes, size_t len, const char *msg, ...)
+{
+	va_list args;
+	va_start(args, msg);
+	vprintk(msg, args);
+	va_end(args);
+	if (len)
+		pr_cont(":");
+	while (len) {
+		pr_cont(" %02x", *bytes);
+		bytes++;
+		len--;
+	}
+	pr_cont("\n");
+}
+#define DEBUG_bytes(bytes, len, msg, ...)	__DEBUG_bytes(bytes, len, KERN_DEBUG msg, ##__VA_ARGS__)
+#else
+#define DEBUG_print(x, ...)			do { } while (0)
+#define DEBUG_bytes(bytes, len, msg, ...)	do { } while (0)
+#endif
+
+/*
+ * DM Integrity profile, protection is performed layer above (dm-crypt)
+ */
+static struct blk_integrity_profile dm_integrity_profile = {
+	.name			= "DM-DIF-EXT-TAG",
+	.generate_fn		= NULL,
+	.verify_fn		= NULL,
+};
+
+static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map);
+static void integrity_bio_wait(struct work_struct *w);
+static void dm_integrity_dtr(struct dm_target *ti);
+
+static void dm_integrity_io_error(struct dm_integrity_c *ic, const char *msg, int err)
+{
+	if (!cmpxchg(&ic->failed, 0, err))
+		DMERR("Error on %s: %d", msg, err);
+}
+
+static int dm_integrity_failed(struct dm_integrity_c *ic)
+{
+	return ACCESS_ONCE(ic->failed);
+}
+
+static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned i,
+					  unsigned j, unsigned char seq)
+{
+	/*
+	 * Xor the number with section and sector, so that if a piece of
+	 * journal is written at wrong place, it is detected.
+	 */
+	return ic->commit_ids[seq] ^ cpu_to_le64(((__u64)i << 32) ^ j);
+}
+
+static void get_area_and_offset(struct dm_integrity_c *ic, sector_t data_sector,
+				sector_t *area, sector_t *offset)
+{
+	__u8 log2_interleave_sectors = ic->sb->log2_interleave_sectors;
+
+	*area = data_sector >> log2_interleave_sectors;
+	*offset = (unsigned)data_sector & ((1U << log2_interleave_sectors) - 1);
+}
+
+#define sector_to_block(ic, n)						\
+do {									\
+	BUG_ON((n) & (unsigned)((ic)->sectors_per_block - 1));		\
+	(n) >>= (ic)->sb->log2_sectors_per_block;			\
+} while (0)
+
+static __u64 get_metadata_sector_and_offset(struct dm_integrity_c *ic, sector_t area,
+					    sector_t offset, unsigned *metadata_offset)
+{
+	__u64 ms;
+	unsigned mo;
+
+	ms = area << ic->sb->log2_interleave_sectors;
+	if (likely(ic->log2_metadata_run >= 0))
+		ms += area << ic->log2_metadata_run;
+	else
+		ms += area * ic->metadata_run;
+	ms >>= ic->log2_buffer_sectors;
+
+	sector_to_block(ic, offset);
+
+	if (likely(ic->log2_tag_size >= 0)) {
+		ms += offset >> (SECTOR_SHIFT + ic->log2_buffer_sectors - ic->log2_tag_size);
+		mo = (offset << ic->log2_tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
+	} else {
+		ms += (__u64)offset * ic->tag_size >> (SECTOR_SHIFT + ic->log2_buffer_sectors);
+		mo = (offset * ic->tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
+	}
+	*metadata_offset = mo;
+	return ms;
+}
+
+static sector_t get_data_sector(struct dm_integrity_c *ic, sector_t area, sector_t offset)
+{
+	sector_t result;
+
+	result = area << ic->sb->log2_interleave_sectors;
+	if (likely(ic->log2_metadata_run >= 0))
+		result += (area + 1) << ic->log2_metadata_run;
+	else
+		result += (area + 1) * ic->metadata_run;
+
+	result += (sector_t)ic->initial_sectors + offset;
+	return result;
+}
+
+static void wraparound_section(struct dm_integrity_c *ic, unsigned *sec_ptr)
+{
+	if (unlikely(*sec_ptr >= ic->journal_sections))
+		*sec_ptr -= ic->journal_sections;
+}
+
+static int sync_rw_sb(struct dm_integrity_c *ic, int op, int op_flags)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+
+	io_req.bi_op = op;
+	io_req.bi_op_flags = op_flags;
+	io_req.mem.type = DM_IO_KMEM;
+	io_req.mem.ptr.addr = ic->sb;
+	io_req.notify.fn = NULL;
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start;
+	io_loc.count = SB_SECTORS;
+
+	return dm_io(&io_req, 1, &io_loc, NULL);
+}
+
+static void access_journal_check(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+				 bool e, const char *function)
+{
+#if defined(CONFIG_DM_DEBUG) || defined(INTERNAL_VERIFY)
+	unsigned limit = e ? ic->journal_section_entries : ic->journal_section_sectors;
+
+	if (unlikely(section >= ic->journal_sections) ||
+	    unlikely(offset >= limit)) {
+		printk(KERN_CRIT "%s: invalid access at (%u,%u), limit (%u,%u)\n",
+			function, section, offset, ic->journal_sections, limit);
+		BUG();
+	}
+#endif
+}
+
+static void page_list_location(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+			       unsigned *pl_index, unsigned *pl_offset)
+{
+	unsigned sector;
+
+	access_journal_check(ic, section, offset, false, "page_list_location");
+
+	sector = section * ic->journal_section_sectors + offset;
+
+	*pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	*pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+}
+
+static struct journal_sector *access_page_list(struct dm_integrity_c *ic, struct page_list *pl,
+					       unsigned section, unsigned offset, unsigned *n_sectors)
+{
+	unsigned pl_index, pl_offset;
+	char *va;
+
+	page_list_location(ic, section, offset, &pl_index, &pl_offset);
+
+	if (n_sectors)
+		*n_sectors = (PAGE_SIZE - pl_offset) >> SECTOR_SHIFT;
+
+	va = lowmem_page_address(pl[pl_index].page);
+
+	return (struct journal_sector *)(va + pl_offset);
+}
+
+static struct journal_sector *access_journal(struct dm_integrity_c *ic, unsigned section, unsigned offset)
+{
+	return access_page_list(ic, ic->journal, section, offset, NULL);
+}
+
+static struct journal_entry *access_journal_entry(struct dm_integrity_c *ic, unsigned section, unsigned n)
+{
+	unsigned rel_sector, offset;
+	struct journal_sector *js;
+
+	access_journal_check(ic, section, n, true, "access_journal_entry");
+
+	rel_sector = n % JOURNAL_BLOCK_SECTORS;
+	offset = n / JOURNAL_BLOCK_SECTORS;
+
+	js = access_journal(ic, section, rel_sector);
+	return (struct journal_entry *)((char *)js + offset * ic->journal_entry_size);
+}
+
+static struct journal_sector *access_journal_data(struct dm_integrity_c *ic, unsigned section, unsigned n)
+{
+	n <<= ic->sb->log2_sectors_per_block;
+
+	n += JOURNAL_BLOCK_SECTORS;
+
+	access_journal_check(ic, section, n, false, "access_journal_data");
+
+	return access_journal(ic, section, n);
+}
+
+static void section_mac(struct dm_integrity_c *ic, unsigned section, __u8 result[JOURNAL_MAC_SIZE])
+{
+	SHASH_DESC_ON_STACK(desc, ic->journal_mac);
+	int r;
+	unsigned j, size;
+
+	desc->tfm = ic->journal_mac;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	r = crypto_shash_init(desc);
+	if (unlikely(r)) {
+		dm_integrity_io_error(ic, "crypto_shash_init", r);
+		goto err;
+	}
+
+	for (j = 0; j < ic->journal_section_entries; j++) {
+		struct journal_entry *je = access_journal_entry(ic, section, j);
+		r = crypto_shash_update(desc, (__u8 *)&je->u.sector, sizeof je->u.sector);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_update", r);
+			goto err;
+		}
+	}
+
+	size = crypto_shash_digestsize(ic->journal_mac);
+
+	if (likely(size <= JOURNAL_MAC_SIZE)) {
+		r = crypto_shash_final(desc, result);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			goto err;
+		}
+		memset(result + size, 0, JOURNAL_MAC_SIZE - size);
+	} else {
+		__u8 digest[size];
+		r = crypto_shash_final(desc, digest);
+		if (unlikely(r)) {
+			dm_integrity_io_error(ic, "crypto_shash_final", r);
+			goto err;
+		}
+		memcpy(result, digest, JOURNAL_MAC_SIZE);
+	}
+
+	return;
+err:
+	memset(result, 0, JOURNAL_MAC_SIZE);
+}
+
+static void rw_section_mac(struct dm_integrity_c *ic, unsigned section, bool wr)
+{
+	__u8 result[JOURNAL_MAC_SIZE];
+	unsigned j;
+
+	if (!ic->journal_mac)
+		return;
+
+	section_mac(ic, section, result);
+
+	for (j = 0; j < JOURNAL_BLOCK_SECTORS; j++) {
+		struct journal_sector *js = access_journal(ic, section, j);
+
+		if (likely(wr))
+			memcpy(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR);
+		else {
+			if (memcmp(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR))
+				dm_integrity_io_error(ic, "journal mac", -EILSEQ);
+		}
+	}
+}
+
+static void complete_journal_op(void *context)
+{
+	struct journal_completion *comp = context;
+	BUG_ON(!atomic_read(&comp->in_flight));
+	if (likely(atomic_dec_and_test(&comp->in_flight)))
+		complete(&comp->comp);
+}
+
+static void xor_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			unsigned n_sections, struct journal_completion *comp)
+{
+	struct async_submit_ctl submit;
+	size_t n_bytes = (size_t)(n_sections * ic->journal_section_sectors) << SECTOR_SHIFT;
+	unsigned pl_index, pl_offset, section_index;
+	struct page_list *source_pl, *target_pl;
+
+	if (likely(encrypt)) {
+		source_pl = ic->journal;
+		target_pl = ic->journal_io;
+	} else {
+		source_pl = ic->journal_io;
+		target_pl = ic->journal;
+	}
+
+	page_list_location(ic, section, 0, &pl_index, &pl_offset);
+
+	atomic_add(roundup(pl_offset + n_bytes, PAGE_SIZE) >> PAGE_SHIFT, &comp->in_flight);
+
+	init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL, complete_journal_op, comp, NULL);
+
+	section_index = pl_index;
+
+	do {
+		size_t this_step;
+		struct page *src_pages[2];
+		struct page *dst_page;
+
+		while (unlikely(pl_index == section_index)) {
+			unsigned dummy;
+			if (likely(encrypt))
+				rw_section_mac(ic, section, true);
+			section++;
+			n_sections--;
+			if (!n_sections)
+				break;
+			page_list_location(ic, section, 0, &section_index, &dummy);
+		}
+
+		this_step = min(n_bytes, (size_t)PAGE_SIZE - pl_offset);
+		dst_page = target_pl[pl_index].page;
+		src_pages[0] = source_pl[pl_index].page;
+		src_pages[1] = ic->journal_xor[pl_index].page;
+
+		async_xor(dst_page, src_pages, pl_offset, 2, this_step, &submit);
+
+		pl_index++;
+		pl_offset = 0;
+		n_bytes -= this_step;
+	} while (n_bytes);
+
+	BUG_ON(n_sections);
+
+	async_tx_issue_pending_all();
+}
+
+static void complete_journal_encrypt(struct crypto_async_request *req, int err)
+{
+	struct journal_completion *comp = req->data;
+	if (unlikely(err)) {
+		if (likely(err == -EINPROGRESS)) {
+			complete(&comp->ic->crypto_backoff);
+			return;
+		}
+		dm_integrity_io_error(comp->ic, "asynchronous encrypt", err);
+	}
+	complete_journal_op(comp);
+}
+
+static bool do_crypt(bool encrypt, struct skcipher_request *req, struct journal_completion *comp)
+{
+	int r;
+	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
+				      complete_journal_encrypt, comp);
+	if (likely(encrypt))
+		r = crypto_skcipher_encrypt(req);
+	else
+		r = crypto_skcipher_decrypt(req);
+	if (likely(!r))
+		return false;
+	if (likely(r == -EINPROGRESS))
+		return true;
+	if (likely(r == -EBUSY)) {
+		wait_for_completion(&comp->ic->crypto_backoff);
+		reinit_completion(&comp->ic->crypto_backoff);
+		return true;
+	}
+	dm_integrity_io_error(comp->ic, "encrypt", r);
+	return false;
+}
+
+static void crypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			  unsigned n_sections, struct journal_completion *comp)
+{
+	struct scatterlist **source_sg;
+	struct scatterlist **target_sg;
+
+	atomic_add(2, &comp->in_flight);
+
+	if (likely(encrypt)) {
+		source_sg = ic->journal_scatterlist;
+		target_sg = ic->journal_io_scatterlist;
+	} else {
+		source_sg = ic->journal_io_scatterlist;
+		target_sg = ic->journal_scatterlist;
+	}
+
+	do {
+		struct skcipher_request *req;
+		unsigned ivsize;
+		char *iv;
+
+		if (likely(encrypt))
+			rw_section_mac(ic, section, true);
+
+		req = ic->sk_requests[section];
+		ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
+		iv = req->iv;
+
+		memcpy(iv, iv + ivsize, ivsize);
+
+		req->src = source_sg[section];
+		req->dst = target_sg[section];
+
+		if (unlikely(do_crypt(encrypt, req, comp)))
+			atomic_inc(&comp->in_flight);
+
+		section++;
+		n_sections--;
+	} while (n_sections);
+
+	atomic_dec(&comp->in_flight);
+	complete_journal_op(comp);
+}
+
+static void encrypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned section,
+			    unsigned n_sections, struct journal_completion *comp)
+{
+	if (ic->journal_xor)
+		return xor_journal(ic, encrypt, section, n_sections, comp);
+	else
+		return crypt_journal(ic, encrypt, section, n_sections, comp);
+}
+
+static void complete_journal_io(unsigned long error, void *context)
+{
+	struct journal_completion *comp = context;
+	if (unlikely(error != 0))
+		dm_integrity_io_error(comp->ic, "writing journal", -EIO);
+	complete_journal_op(comp);
+}
+
+static void rw_journal(struct dm_integrity_c *ic, int op, int op_flags, unsigned section,
+		       unsigned n_sections, struct journal_completion *comp)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+	unsigned sector, n_sectors, pl_index, pl_offset;
+	int r;
+
+	if (unlikely(dm_integrity_failed(ic))) {
+		if (comp)
+			complete_journal_io(-1UL, comp);
+		return;
+	}
+
+	sector = section * ic->journal_section_sectors;
+	n_sectors = n_sections * ic->journal_section_sectors;
+
+	pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+
+	io_req.bi_op = op;
+	io_req.bi_op_flags = op_flags;
+	io_req.mem.type = DM_IO_PAGE_LIST;
+	if (ic->journal_io)
+		io_req.mem.ptr.pl = &ic->journal_io[pl_index];
+	else
+		io_req.mem.ptr.pl = &ic->journal[pl_index];
+	io_req.mem.offset = pl_offset;
+	if (likely(comp != NULL)) {
+		io_req.notify.fn = complete_journal_io;
+		io_req.notify.context = comp;
+	} else {
+		io_req.notify.fn = NULL;
+	}
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start + SB_SECTORS + sector;
+	io_loc.count = n_sectors;
+
+	r = dm_io(&io_req, 1, &io_loc, NULL);
+	if (unlikely(r)) {
+		dm_integrity_io_error(ic, op == REQ_OP_READ ? "reading journal" : "writing journal", r);
+		if (comp) {
+			WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
+			complete_journal_io(-1UL, comp);
+		}
+	}
+}
+
+static void write_journal(struct dm_integrity_c *ic, unsigned commit_start, unsigned commit_sections)
+{
+	struct journal_completion io_comp;
+	struct journal_completion crypt_comp_1;
+	struct journal_completion crypt_comp_2;
+	unsigned i;
+
+	io_comp.ic = ic;
+	io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp);
+
+	if (commit_start + commit_sections <= ic->journal_sections) {
+		io_comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+		if (ic->journal_io) {
+			crypt_comp_1.ic = ic;
+			crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+			crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, true, commit_start, commit_sections, &crypt_comp_1);
+			wait_for_completion_io(&crypt_comp_1.comp);
+		} else {
+			for (i = 0; i < commit_sections; i++)
+				rw_section_mac(ic, commit_start + i, true);
+		}
+		rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, commit_sections, &io_comp);
+	} else {
+		unsigned to_end;
+		io_comp.in_flight = (atomic_t)ATOMIC_INIT(2);
+		to_end = ic->journal_sections - commit_start;
+		if (ic->journal_io) {
+			crypt_comp_1.ic = ic;
+			crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+			crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, true, commit_start, to_end, &crypt_comp_1);
+			if (try_wait_for_completion(&crypt_comp_1.comp)) {
+				rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+				crypt_comp_1.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_1.comp);
+				crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
+				encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_1);
+				wait_for_completion_io(&crypt_comp_1.comp);
+			} else {
+				crypt_comp_2.ic = ic;
+				crypt_comp_2.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp_2.comp);
+				crypt_comp_2.in_flight = (atomic_t)ATOMIC_INIT(0);
+				encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_2);
+				wait_for_completion_io(&crypt_comp_1.comp);
+				rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+				wait_for_completion_io(&crypt_comp_2.comp);
+			}
+		} else {
+			for (i = 0; i < to_end; i++)
+				rw_section_mac(ic, commit_start + i, true);
+			rw_journal(ic, REQ_OP_WRITE, REQ_FUA, commit_start, to_end, &io_comp);
+			for (i = 0; i < commit_sections - to_end; i++)
+				rw_section_mac(ic, i, true);
+		}
+		rw_journal(ic, REQ_OP_WRITE, REQ_FUA, 0, commit_sections - to_end, &io_comp);
+	}
+
+	wait_for_completion_io(&io_comp.comp);
+}
+
+static void copy_from_journal(struct dm_integrity_c *ic, unsigned section, unsigned offset,
+			      unsigned n_sectors, sector_t target, io_notify_fn fn, void *data)
+{
+	struct dm_io_request io_req;
+	struct dm_io_region io_loc;
+	int r;
+	unsigned sector, pl_index, pl_offset;
+
+	BUG_ON((target | n_sectors | offset) & (unsigned)(ic->sectors_per_block - 1));
+
+	if (unlikely(dm_integrity_failed(ic))) {
+		fn(-1UL, data);
+		return;
+	}
+
+	sector = section * ic->journal_section_sectors + JOURNAL_BLOCK_SECTORS + offset;
+
+	pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
+	pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
+
+	io_req.bi_op = REQ_OP_WRITE;
+	io_req.bi_op_flags = 0;
+	io_req.mem.type = DM_IO_PAGE_LIST;
+	io_req.mem.ptr.pl = &ic->journal[pl_index];
+	io_req.mem.offset = pl_offset;
+	io_req.notify.fn = fn;
+	io_req.notify.context = data;
+	io_req.client = ic->io;
+	io_loc.bdev = ic->dev->bdev;
+	io_loc.sector = ic->start + target;
+	io_loc.count = n_sectors;
+
+	r = dm_io(&io_req, 1, &io_loc, NULL);
+	if (unlikely(r)) {
+		WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
+		fn(-1UL, data);
+	}
+}
+
+static bool add_new_range(struct dm_integrity_c *ic, struct dm_integrity_range *new_range)
+{
+	struct rb_node **n = &ic->in_progress.rb_node;
+	struct rb_node *parent;
+
+	BUG_ON((new_range->logical_sector | new_range->n_sectors) & (unsigned)(ic->sectors_per_block - 1));
+
+	parent = NULL;
+
+	while (*n) {
+		struct dm_integrity_range *range = container_of(*n, struct dm_integrity_range, node);
+
+		parent = *n;
+		if (new_range->logical_sector + new_range->n_sectors <= range->logical_sector) {
+			n = &range->node.rb_left;
+		} else if (new_range->logical_sector >= range->logical_sector + range->n_sectors) {
+			n = &range->node.rb_right;
+		} else {
+			return false;
+		}
+	}
+
+	rb_link_node(&new_range->node, parent, n);
+	rb_insert_color(&new_range->node, &ic->in_progress);
+
+	return true;
+}
+
+static void remove_range_unlocked(struct dm_integrity_c *ic, struct dm_integrity_range *range)
+{
+	rb_erase(&range->node, &ic->in_progress);
+	wake_up_locked(&ic->endio_wait);
+}
+
+static void remove_range(struct dm_integrity_c *ic, struct dm_integrity_range *range)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ic->endio_wait.lock, flags);
+	remove_range_unlocked(ic, range);
+	spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
+}
+
+static void init_journal_node(struct journal_node *node)
+{
+	RB_CLEAR_NODE(&node->node);
+	node->sector = (sector_t)-1;
+}
+
+static void add_journal_node(struct dm_integrity_c *ic, struct journal_node *node, sector_t sector)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	node->sector = sector;
+	BUG_ON(!RB_EMPTY_NODE(&node->node));
+
+	link = &ic->journal_tree_root.rb_node;
+	parent = NULL;
+
+	while (*link) {
+		struct journal_node *j;
+		parent = *link;
+		j = container_of(parent, struct journal_node, node);
+		if (sector < j->sector)
+			link = &j->node.rb_left;
+		else
+			link = &j->node.rb_right;
+	}
+
+	rb_link_node(&node->node, parent, link);
+	rb_insert_color(&node->node, &ic->journal_tree_root);
+}
+
+static void remove_journal_node(struct dm_integrity_c *ic, struct journal_node *node)
+{
+	BUG_ON(RB_EMPTY_NODE(&node->node));
+	rb_erase(&node->node, &ic->journal_tree_root);
+	init_journal_node(node);
+}
+
+#define NOT_FOUND	(-1U)
+
+static unsigned find_journal_node(struct dm_integrity_c *ic, sector_t sector, sector_t *next_sector)
+{
+	struct rb_node *n = ic->journal_tree_root.rb_node;
+	unsigned found = NOT_FOUND;
+	*next_sector = (sector_t)-1;
+	while (n) {
+		struct journal_node *j = container_of(n, struct journal_node, node);
+		if (sector == j->sector) {
+			found = j - ic->journal_tree;
+		}
+		if (sector < j->sector) {
+			*next_sector = j->sector;
+			n = j->node.rb_left;
+		} else {
+			n = j->node.rb_right;
+		}
+	}
+
+	return found;
+}
+
+static bool test_journal_node(struct dm_integrity_c *ic, unsigned pos, sector_t sector)
+{
+	struct journal_node *node, *next_node;
+	struct rb_node *next;
+
+	if (unlikely(pos >= ic->journal_entries))
+		return false;
+	node = &ic->journal_tree[pos];
+	if (unlikely(RB_EMPTY_NODE(&node->node)))
+		return false;
+	if (unlikely(node->sector != sector))
+		return false;
+
+	next = rb_next(&node->node);
+	if (unlikely(!next))
+		return true;
+
+	next_node = container_of(next, struct journal_node, node);
+	return next_node->sector != sector;
+}
+
+static bool find_newer_committed_node(struct dm_integrity_c *ic, struct journal_node *node)
+{
+	struct rb_node *next;
+	struct journal_node *next_node;
+	unsigned next_section;
+
+	BUG_ON(RB_EMPTY_NODE(&node->node));
+
+	next = rb_next(&node->node);
+	if (unlikely(!next))
+		return false;
+
+	next_node = container_of(next, struct journal_node, node);
+
+	if (next_node->sector != node->sector)
+		return false;
+
+	next_section = (unsigned)(next_node - ic->journal_tree) / ic->journal_section_entries;
+	if (next_section >= ic->committed_section &&
+	    next_section < ic->committed_section + ic->n_committed_sections)
+		return true;
+	if (next_section + ic->journal_sections < ic->committed_section + ic->n_committed_sections)
+		return true;
+
+	return false;
+}
+
+#define TAG_READ	0
+#define TAG_WRITE	1
+#define TAG_CMP		2
+
+static int dm_integrity_rw_tag(struct dm_integrity_c *ic, unsigned char *tag, sector_t *metadata_block,
+			       unsigned *metadata_offset, unsigned total_size, int op)
+{
+	do {
+		unsigned char *data, *dp;
+		struct dm_buffer *b;
+		unsigned to_copy;
+		int r;
+
+		r = dm_integrity_failed(ic);
+		if (unlikely(r))
+			return r;
+
+		data = dm_bufio_read(ic->bufio, *metadata_block, &b);
+		if (unlikely(IS_ERR(data)))
+			return PTR_ERR(data);
+
+		to_copy = min((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - *metadata_offset, total_size);
+		dp = data + *metadata_offset;
+		if (op == TAG_READ) {
+			memcpy(tag, dp, to_copy);
+		} else if (op == TAG_WRITE) {
+			memcpy(dp, tag, to_copy);
+			dm_bufio_mark_buffer_dirty(b);
+		} else  {
+			/* e.g.: op == TAG_CMP */
+			if (unlikely(memcmp(dp, tag, to_copy))) {
+				unsigned i;
+
+				for (i = 0; i < to_copy; i++) {
+					if (dp[i] != tag[i])
+						break;
+					total_size--;
+				}
+				dm_bufio_release(b);
+				return total_size;
+			}
+		}
+		dm_bufio_release(b);
+
+		tag += to_copy;
+		*metadata_offset += to_copy;
+		if (unlikely(*metadata_offset == 1U << SECTOR_SHIFT << ic->log2_buffer_sectors)) {
+			(*metadata_block)++;
+			*metadata_offset = 0;
+		}
+		total_size -= to_copy;
+	} while (unlikely(total_size));
+
+	return 0;
+}
+
+static void dm_integrity_flush_buffers(struct dm_integrity_c *ic)
+{
+	int r;
+	r = dm_bufio_write_dirty_buffers(ic->bufio);
+	if (unlikely(r))
+		dm_integrity_io_error(ic, "writing tags", r);
+}
+
+static void sleep_on_endio_wait(struct dm_integrity_c *ic)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	__add_wait_queue(&ic->endio_wait, &wait);
+	__set_current_state(TASK_UNINTERRUPTIBLE);
+	spin_unlock_irq(&ic->endio_wait.lock);
+	io_schedule();
+	spin_lock_irq(&ic->endio_wait.lock);
+	__remove_wait_queue(&ic->endio_wait, &wait);
+}
+
+static void autocommit_fn(unsigned long data)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)data;
+
+	if (likely(!dm_integrity_failed(ic)))
+		queue_work(ic->commit_wq, &ic->commit_work);
+}
+
+static void schedule_autocommit(struct dm_integrity_c *ic)
+{
+	if (!timer_pending(&ic->autocommit_timer))
+		mod_timer(&ic->autocommit_timer, jiffies + ic->autocommit_jiffies);
+}
+
+static void submit_flush_bio(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
+{
+	struct bio *bio;
+	spin_lock_irq(&ic->endio_wait.lock);
+	bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+	bio_list_add(&ic->flush_bio_list, bio);
+	spin_unlock_irq(&ic->endio_wait.lock);
+	queue_work(ic->commit_wq, &ic->commit_work);
+}
+
+static void do_endio(struct dm_integrity_c *ic, struct bio *bio)
+{
+	int r = dm_integrity_failed(ic);
+	if (unlikely(r) && !bio->bi_error)
+		bio->bi_error = r;
+	bio_endio(bio);
+}
+
+static void do_endio_flush(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
+{
+	struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+
+	if (unlikely(dio->fua) && likely(!bio->bi_error) && likely(!dm_integrity_failed(ic)))
+		submit_flush_bio(ic, dio);
+	else
+		do_endio(ic, bio);
+}
+
+static void dec_in_flight(struct dm_integrity_io *dio)
+{
+	if (atomic_dec_and_test(&dio->in_flight)) {
+		struct dm_integrity_c *ic = dio->ic;
+		struct bio *bio;
+
+		remove_range(ic, &dio->range);
+
+		if (unlikely(dio->write))
+			schedule_autocommit(ic);
+
+		bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+
+		if (unlikely(dio->bi_error) && !bio->bi_error)
+			bio->bi_error = dio->bi_error;
+		if (likely(!bio->bi_error) && unlikely(bio_sectors(bio) != dio->range.n_sectors)) {
+			dio->range.logical_sector += dio->range.n_sectors;
+			bio_advance(bio, dio->range.n_sectors << SECTOR_SHIFT);
+			INIT_WORK(&dio->work, integrity_bio_wait);
+			queue_work(ic->wait_wq, &dio->work);
+			return;
+		}
+		do_endio_flush(ic, dio);
+	}
+}
+
+static void integrity_end_io(struct bio *bio)
+{
+	struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
+
+	bio->bi_iter = dio->orig_bi_iter;
+	bio->bi_bdev = dio->orig_bi_bdev;
+	if (dio->orig_bi_integrity) {
+		bio->bi_integrity = dio->orig_bi_integrity;
+		bio->bi_opf |= REQ_INTEGRITY;
+	}
+	bio->bi_end_io = dio->orig_bi_end_io;
+
+	if (dio->completion)
+		complete(dio->completion);
+
+	dec_in_flight(dio);
+}
+
+static void integrity_sector_checksum(struct dm_integrity_c *ic, sector_t sector,
+				      const char *data, char *result)
+{
+	__u64 sector_le = cpu_to_le64(sector);
+	SHASH_DESC_ON_STACK(req, ic->internal_hash);
+	int r;
+	unsigned digest_size;
+
+	req->tfm = ic->internal_hash;
+	req->flags = 0;
+
+	r = crypto_shash_init(req);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_init", r);
+		goto failed;
+	}
+
+	r = crypto_shash_update(req, (const __u8 *)&sector_le, sizeof sector_le);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_update", r);
+		goto failed;
+	}
+
+	r = crypto_shash_update(req, data, ic->sectors_per_block << SECTOR_SHIFT);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_update", r);
+		goto failed;
+	}
+
+	r = crypto_shash_final(req, result);
+	if (unlikely(r < 0)) {
+		dm_integrity_io_error(ic, "crypto_shash_final", r);
+		goto failed;
+	}
+
+	digest_size = crypto_shash_digestsize(ic->internal_hash);
+	if (unlikely(digest_size < ic->tag_size))
+		memset(result + digest_size, 0, ic->tag_size - digest_size);
+
+	return;
+
+failed:
+	/* this shouldn't happen anyway, the hash functions have no reason to fail */
+	get_random_bytes(result, ic->tag_size);
+}
+
+static void integrity_metadata(struct work_struct *w)
+{
+	struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
+	struct dm_integrity_c *ic = dio->ic;
+
+	int r;
+
+	if (ic->internal_hash) {
+		struct bvec_iter iter;
+		struct bio_vec bv;
+		unsigned digest_size = crypto_shash_digestsize(ic->internal_hash);
+		struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+		char *checksums;
+		unsigned extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0;
+		char checksums_onstack[ic->tag_size + extra_space];
+		unsigned sectors_to_process = dio->range.n_sectors;
+		sector_t sector = dio->range.logical_sector;
+
+		if (unlikely(ic->mode == 'R'))
+			goto skip_io;
+
+		checksums = kmalloc((PAGE_SIZE >> SECTOR_SHIFT >> ic->sb->log2_sectors_per_block) * ic->tag_size + extra_space,
+				    GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
+		if (!checksums)
+			checksums = checksums_onstack;
+
+		__bio_for_each_segment(bv, bio, iter, dio->orig_bi_iter) {
+			unsigned pos;
+			char *mem, *checksums_ptr;
+
+again:
+			mem = (char *)kmap_atomic(bv.bv_page) + bv.bv_offset;
+			pos = 0;
+			checksums_ptr = checksums;
+			do {
+				integrity_sector_checksum(ic, sector, mem + pos, checksums_ptr);
+				checksums_ptr += ic->tag_size;
+				sectors_to_process -= ic->sectors_per_block;
+				pos += ic->sectors_per_block << SECTOR_SHIFT;
+				sector += ic->sectors_per_block;
+			} while (pos < bv.bv_len && sectors_to_process && checksums != checksums_onstack);
+			kunmap_atomic(mem);
+
+			r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
+						checksums_ptr - checksums, !dio->write ? TAG_CMP : TAG_WRITE);
+			if (unlikely(r)) {
+				if (r > 0) {
+					DMERR("Checksum failed at sector 0x%llx",
+					      (unsigned long long)(sector - ((r + ic->tag_size - 1) / ic->tag_size)));
+					r = -EILSEQ;
+				}
+				if (likely(checksums != checksums_onstack))
+					kfree(checksums);
+				goto error;
+			}
+
+			if (!sectors_to_process)
+				break;
+
+			if (unlikely(pos < bv.bv_len)) {
+				bv.bv_offset += pos;
+				bv.bv_len -= pos;
+				goto again;
+			}
+		}
+
+		if (likely(checksums != checksums_onstack))
+			kfree(checksums);
+	} else {
+		struct bio_integrity_payload *bip = dio->orig_bi_integrity;
+
+		if (bip) {
+			struct bio_vec biv;
+			struct bvec_iter iter;
+			unsigned data_to_process = dio->range.n_sectors;
+			sector_to_block(ic, data_to_process);
+			data_to_process *= ic->tag_size;
+
+			bip_for_each_vec(biv, bip, iter) {
+				unsigned char *tag;
+				unsigned this_len;
+
+				BUG_ON(PageHighMem(biv.bv_page));
+				tag = lowmem_page_address(biv.bv_page) + biv.bv_offset;
+				this_len = min(biv.bv_len, data_to_process);
+				r = dm_integrity_rw_tag(ic, tag, &dio->metadata_block, &dio->metadata_offset,
+							this_len, !dio->write ? TAG_READ : TAG_WRITE);
+				if (unlikely(r))
+					goto error;
+				data_to_process -= this_len;
+				if (!data_to_process)
+					break;
+			}
+		}
+	}
+skip_io:
+	dec_in_flight(dio);
+	return;
+error:
+	dio->bi_error = r;
+	dec_in_flight(dio);
+}
+
+static int dm_integrity_map(struct dm_target *ti, struct bio *bio)
+{
+	struct dm_integrity_c *ic = ti->private;
+	struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
+	struct bio_integrity_payload *bip;
+
+	sector_t area, offset;
+
+	dio->ic = ic;
+	dio->bi_error = 0;
+
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+		submit_flush_bio(ic, dio);
+		return DM_MAPIO_SUBMITTED;
+	}
+
+	dio->range.logical_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
+	dio->write = bio_op(bio) == REQ_OP_WRITE;
+	dio->fua = dio->write && bio->bi_opf & REQ_FUA;
+	if (unlikely(dio->fua)) {
+		/*
+		 * Don't pass down the FUA flag because we have to flush
+		 * disk cache anyway.
+		 */
+		bio->bi_opf &= ~REQ_FUA;
+	}
+	if (unlikely(dio->range.logical_sector + bio_sectors(bio) > ic->provided_data_sectors)) {
+		DMERR("Too big sector number: 0x%llx + 0x%x > 0x%llx",
+		      (unsigned long long)dio->range.logical_sector, bio_sectors(bio),
+		      (unsigned long long)ic->provided_data_sectors);
+		return -EIO;
+	}
+	if (unlikely((dio->range.logical_sector | bio_sectors(bio)) & (unsigned)(ic->sectors_per_block - 1))) {
+		DMERR("Bio not aligned on %u sectors: 0x%llx, 0x%x",
+		      ic->sectors_per_block,
+		      (unsigned long long)dio->range.logical_sector, bio_sectors(bio));
+		return -EIO;
+	}
+
+	if (ic->sectors_per_block > 1) {
+		struct bvec_iter iter;
+		struct bio_vec bv;
+		bio_for_each_segment(bv, bio, iter) {
+			if (unlikely((bv.bv_offset | bv.bv_len) & ((ic->sectors_per_block << SECTOR_SHIFT) - 1))) {
+				DMERR("Bio vector (%u,%u) is not aligned on %u-sector boundary",
+					bv.bv_offset, bv.bv_len, ic->sectors_per_block);
+				return -EIO;
+			}
+		}
+	}
+
+	bip = bio_integrity(bio);
+	if (!ic->internal_hash) {
+		if (bip) {
+			unsigned wanted_tag_size = bio_sectors(bio) >> ic->sb->log2_sectors_per_block;
+			if (ic->log2_tag_size >= 0)
+				wanted_tag_size <<= ic->log2_tag_size;
+			else
+				wanted_tag_size *= ic->tag_size;
+			if (unlikely(wanted_tag_size != bip->bip_iter.bi_size)) {
+				DMERR("Invalid integrity data size %u, expected %u", bip->bip_iter.bi_size, wanted_tag_size);
+				return -EIO;
+			}
+		}
+	} else {
+		if (unlikely(bip != NULL)) {
+			DMERR("Unexpected integrity data when using internal hash");
+			return -EIO;
+		}
+	}
+
+	if (unlikely(ic->mode == 'R') && unlikely(dio->write))
+		return -EIO;
+
+	get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
+	dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
+	bio->bi_iter.bi_sector = get_data_sector(ic, area, offset);
+
+	dm_integrity_map_continue(dio, true);
+	return DM_MAPIO_SUBMITTED;
+}
+
+static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio,
+				 unsigned journal_section, unsigned journal_entry)
+{
+	struct dm_integrity_c *ic = dio->ic;
+	sector_t logical_sector;
+	unsigned n_sectors;
+
+	logical_sector = dio->range.logical_sector;
+	n_sectors = dio->range.n_sectors;
+	do {
+		struct bio_vec bv = bio_iovec(bio);
+		char *mem;
+
+		if (unlikely(bv.bv_len >> SECTOR_SHIFT > n_sectors))
+			bv.bv_len = n_sectors << SECTOR_SHIFT;
+		n_sectors -= bv.bv_len >> SECTOR_SHIFT;
+		bio_advance_iter(bio, &bio->bi_iter, bv.bv_len);
+retry_kmap:
+		mem = kmap_atomic(bv.bv_page);
+		if (likely(dio->write))
+			flush_dcache_page(bv.bv_page);
+
+		do {
+			struct journal_entry *je = access_journal_entry(ic, journal_section, journal_entry);
+
+			if (unlikely(!dio->write)) {
+				struct journal_sector *js;
+				char *mem_ptr;
+				unsigned s;
+
+				if (unlikely(journal_entry_is_inprogress(je))) {
+					flush_dcache_page(bv.bv_page);
+					kunmap_atomic(mem);
+
+					__io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
+					goto retry_kmap;
+				}
+				smp_rmb();
+				BUG_ON(journal_entry_get_sector(je) != logical_sector);
+				js = access_journal_data(ic, journal_section, journal_entry);
+				mem_ptr = mem + bv.bv_offset;
+				s = 0;
+				do {
+					memcpy(mem_ptr, js, JOURNAL_SECTOR_DATA);
+					*(commit_id_t *)(mem_ptr + JOURNAL_SECTOR_DATA) = je->last_bytes[s];
+					js++;
+					mem_ptr += 1 << SECTOR_SHIFT;
+				} while (++s < ic->sectors_per_block);
+#ifdef INTERNAL_VERIFY
+				if (ic->internal_hash) {
+					char checksums_onstack[max(crypto_shash_digestsize(ic->internal_hash), ic->tag_size)];
+
+					integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack);
+					if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) {
+						DMERR("Checksum failed when reading from journal, at sector 0x%llx",
+						      (unsigned long long)logical_sector);
+					}
+				}
+#endif
+			}
+
+			if (!ic->internal_hash) {
+				struct bio_integrity_payload *bip = bio_integrity(bio);
+				unsigned tag_todo = ic->tag_size;
+				char *tag_ptr = journal_entry_tag(ic, je);
+
+				if (bip) do {
+					struct bio_vec biv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+					unsigned tag_now = min(biv.bv_len, tag_todo);
+					char *tag_addr;
+					BUG_ON(PageHighMem(biv.bv_page));
+					tag_addr = lowmem_page_address(biv.bv_page) + biv.bv_offset;
+					if (likely(dio->write))
+						memcpy(tag_ptr, tag_addr, tag_now);
+					else
+						memcpy(tag_addr, tag_ptr, tag_now);
+					bvec_iter_advance(bip->bip_vec, &bip->bip_iter, tag_now);
+					tag_ptr += tag_now;
+					tag_todo -= tag_now;
+				} while (unlikely(tag_todo)); else {
+					if (likely(dio->write))
+						memset(tag_ptr, 0, tag_todo);
+				}
+			}
+
+			if (likely(dio->write)) {
+				struct journal_sector *js;
+				unsigned s;
+
+				js = access_journal_data(ic, journal_section, journal_entry);
+				memcpy(js, mem + bv.bv_offset, ic->sectors_per_block << SECTOR_SHIFT);
+
+				s = 0;
+				do {
+					je->last_bytes[s] = js[s].commit_id;
+				} while (++s < ic->sectors_per_block);
+
+				if (ic->internal_hash) {
+					unsigned digest_size = crypto_shash_digestsize(ic->internal_hash);
+					if (unlikely(digest_size > ic->tag_size)) {
+						char checksums_onstack[digest_size];
+						integrity_sector_checksum(ic, logical_sector, (char *)js, checksums_onstack);
+						memcpy(journal_entry_tag(ic, je), checksums_onstack, ic->tag_size);
+					} else
+						integrity_sector_checksum(ic, logical_sector, (char *)js, journal_entry_tag(ic, je));
+				}
+
+				journal_entry_set_sector(je, logical_sector);
+			}
+			logical_sector += ic->sectors_per_block;
+
+			journal_entry++;
+			if (unlikely(journal_entry == ic->journal_section_entries)) {
+				journal_entry = 0;
+				journal_section++;
+				wraparound_section(ic, &journal_section);
+			}
+
+			bv.bv_offset += ic->sectors_per_block << SECTOR_SHIFT;
+		} while (bv.bv_len -= ic->sectors_per_block << SECTOR_SHIFT);
+
+		if (unlikely(!dio->write))
+			flush_dcache_page(bv.bv_page);
+		kunmap_atomic(mem);
+	} while (n_sectors);
+
+	if (likely(dio->write)) {
+		smp_mb();
+		if (unlikely(waitqueue_active(&ic->copy_to_journal_wait)))
+			wake_up(&ic->copy_to_journal_wait);
+		if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold) {
+			queue_work(ic->commit_wq, &ic->commit_work);
+		} else {
+			schedule_autocommit(ic);
+		}
+	} else {
+		remove_range(ic, &dio->range);
+	}
+
+	if (unlikely(bio->bi_iter.bi_size)) {
+		sector_t area, offset;
+
+		dio->range.logical_sector = logical_sector;
+		get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
+		dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
+		return true;
+	}
+
+	return false;
+}
+
+static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map)
+{
+	struct dm_integrity_c *ic = dio->ic;
+	struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
+	unsigned journal_section, journal_entry;
+	unsigned journal_read_pos;
+	struct completion read_comp;
+	bool need_sync_io = ic->internal_hash && !dio->write;
+
+	if (need_sync_io && from_map) {
+		INIT_WORK(&dio->work, integrity_bio_wait);
+		queue_work(ic->metadata_wq, &dio->work);
+		return;
+	}
+
+lock_retry:
+	spin_lock_irq(&ic->endio_wait.lock);
+retry:
+	if (unlikely(dm_integrity_failed(ic))) {
+		spin_unlock_irq(&ic->endio_wait.lock);
+		do_endio(ic, bio);
+		return;
+	}
+	dio->range.n_sectors = bio_sectors(bio);
+	journal_read_pos = NOT_FOUND;
+	if (likely(ic->mode == 'J')) {
+		if (dio->write) {
+			unsigned next_entry, i, pos;
+			unsigned ws, we;
+
+			dio->range.n_sectors = min(dio->range.n_sectors, ic->free_sectors);
+			if (unlikely(!dio->range.n_sectors))
+				goto sleep;
+			ic->free_sectors -= dio->range.n_sectors;
+			journal_section = ic->free_section;
+			journal_entry = ic->free_section_entry;
+
+			next_entry = ic->free_section_entry + dio->range.n_sectors;
+			ic->free_section_entry = next_entry % ic->journal_section_entries;
+			ic->free_section += next_entry / ic->journal_section_entries;
+			ic->n_uncommitted_sections += next_entry / ic->journal_section_entries;
+			wraparound_section(ic, &ic->free_section);
+
+			pos = journal_section * ic->journal_section_entries + journal_entry;
+			ws = journal_section;
+			we = journal_entry;
+			i = 0;
+			do {
+				struct journal_entry *je;
+
+				add_journal_node(ic, &ic->journal_tree[pos], dio->range.logical_sector + i);
+				pos++;
+				if (unlikely(pos >= ic->journal_entries))
+					pos = 0;
+
+				je = access_journal_entry(ic, ws, we);
+				BUG_ON(!journal_entry_is_unused(je));
+				journal_entry_set_inprogress(je);
+				we++;
+				if (unlikely(we == ic->journal_section_entries)) {
+					we = 0;
+					ws++;
+					wraparound_section(ic, &ws);
+				}
+			} while ((i += ic->sectors_per_block) < dio->range.n_sectors);
+
+			spin_unlock_irq(&ic->endio_wait.lock);
+			goto journal_read_write;
+		} else {
+			sector_t next_sector;
+			journal_read_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
+			if (likely(journal_read_pos == NOT_FOUND)) {
+				if (unlikely(dio->range.n_sectors > next_sector - dio->range.logical_sector))
+					dio->range.n_sectors = next_sector - dio->range.logical_sector;
+			} else {
+				unsigned i;
+				unsigned jp = journal_read_pos + 1;
+				for (i = ic->sectors_per_block; i < dio->range.n_sectors; i += ic->sectors_per_block, jp++) {
+					if (!test_journal_node(ic, jp, dio->range.logical_sector + i))
+						break;
+				}
+				dio->range.n_sectors = i;
+			}
+		}
+	}
+	if (unlikely(!add_new_range(ic, &dio->range))) {
+		/*
+		 * We must not sleep in the request routine because it could
+		 * stall bios on current->bio_list.
+		 * So, we offload the bio to a workqueue if we have to sleep.
+		 */
+sleep:
+		if (from_map) {
+			spin_unlock_irq(&ic->endio_wait.lock);
+			INIT_WORK(&dio->work, integrity_bio_wait);
+			queue_work(ic->wait_wq, &dio->work);
+			return;
+		} else {
+			sleep_on_endio_wait(ic);
+			goto retry;
+		}
+	}
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (unlikely(journal_read_pos != NOT_FOUND)) {
+		journal_section = journal_read_pos / ic->journal_section_entries;
+		journal_entry = journal_read_pos % ic->journal_section_entries;
+		goto journal_read_write;
+	}
+
+	dio->in_flight = (atomic_t)ATOMIC_INIT(2);
+
+	if (need_sync_io) {
+		read_comp = COMPLETION_INITIALIZER_ONSTACK(read_comp);
+		dio->completion = &read_comp;
+	} else
+		dio->completion = NULL;
+
+	dio->orig_bi_iter = bio->bi_iter;
+
+	dio->orig_bi_bdev = bio->bi_bdev;
+	bio->bi_bdev = ic->dev->bdev;
+
+	dio->orig_bi_integrity = bio_integrity(bio);
+	bio->bi_integrity = NULL;
+	bio->bi_opf &= ~REQ_INTEGRITY;
+
+	dio->orig_bi_end_io = bio->bi_end_io;
+	bio->bi_end_io = integrity_end_io;
+
+	bio->bi_iter.bi_size = dio->range.n_sectors << SECTOR_SHIFT;
+	bio->bi_iter.bi_sector += ic->start;
+	generic_make_request(bio);
+
+	if (need_sync_io) {
+		wait_for_completion_io(&read_comp);
+		integrity_metadata(&dio->work);
+	} else {
+		INIT_WORK(&dio->work, integrity_metadata);
+		queue_work(ic->metadata_wq, &dio->work);
+	}
+
+	return;
+
+journal_read_write:
+	if (unlikely(__journal_read_write(dio, bio, journal_section, journal_entry)))
+		goto lock_retry;
+
+	do_endio_flush(ic, dio);
+}
+
+
+static void integrity_bio_wait(struct work_struct *w)
+{
+	struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
+
+	dm_integrity_map_continue(dio, false);
+}
+
+static void pad_uncommitted(struct dm_integrity_c *ic)
+{
+	if (ic->free_section_entry) {
+		ic->free_sectors -= ic->journal_section_entries - ic->free_section_entry;
+		ic->free_section_entry = 0;
+		ic->free_section++;
+		wraparound_section(ic, &ic->free_section);
+		ic->n_uncommitted_sections++;
+	}
+}
+
+static void integrity_commit(struct work_struct *w)
+{
+	struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, commit_work);
+	unsigned commit_start, commit_sections;
+	unsigned i, j, n;
+	struct bio *flushes;
+
+	del_timer(&ic->autocommit_timer);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	flushes = bio_list_get(&ic->flush_bio_list);
+	if (unlikely(ic->mode != 'J')) {
+		spin_unlock_irq(&ic->endio_wait.lock);
+		dm_integrity_flush_buffers(ic);
+		goto release_flush_bios;
+	}
+
+	pad_uncommitted(ic);
+	commit_start = ic->uncommitted_section;
+	commit_sections = ic->n_uncommitted_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (!commit_sections)
+		goto release_flush_bios;
+
+	i = commit_start;
+	for (n = 0; n < commit_sections; n++) {
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je;
+			je = access_journal_entry(ic, i, j);
+			io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
+		}
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js;
+			js = access_journal(ic, i, j);
+			js->commit_id = dm_integrity_commit_id(ic, i, j, ic->commit_seq);
+		}
+		i++;
+		if (unlikely(i >= ic->journal_sections))
+			ic->commit_seq = next_commit_seq(ic->commit_seq);
+		wraparound_section(ic, &i);
+	}
+	smp_rmb();
+
+	write_journal(ic, commit_start, commit_sections);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	ic->uncommitted_section += commit_sections;
+	wraparound_section(ic, &ic->uncommitted_section);
+	ic->n_uncommitted_sections -= commit_sections;
+	ic->n_committed_sections += commit_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (ACCESS_ONCE(ic->free_sectors) <= ic->free_sectors_threshold)
+		queue_work(ic->writer_wq, &ic->writer_work);
+
+release_flush_bios:
+	while (flushes) {
+		struct bio *next = flushes->bi_next;
+		flushes->bi_next = NULL;
+		do_endio(ic, flushes);
+		flushes = next;
+	}
+}
+
+static void complete_copy_from_journal(unsigned long error, void *context)
+{
+	struct journal_io *io = context;
+	struct journal_completion *comp = io->comp;
+	struct dm_integrity_c *ic = comp->ic;
+	remove_range(ic, &io->range);
+	mempool_free(io, ic->journal_io_mempool);
+	if (unlikely(error != 0))
+		dm_integrity_io_error(ic, "copying from journal", -EIO);
+	complete_journal_op(comp);
+}
+
+static void restore_last_bytes(struct dm_integrity_c *ic, struct journal_sector *js,
+			       struct journal_entry *je)
+{
+	unsigned s = 0;
+	do {
+		js->commit_id = je->last_bytes[s];
+		js++;
+	} while (++s < ic->sectors_per_block);
+}
+
+static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start,
+			     unsigned write_sections, bool from_replay)
+{
+	unsigned i, j, n;
+	struct journal_completion comp;
+
+	comp.ic = ic;
+	comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+	comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+
+	i = write_start;
+	for (n = 0; n < write_sections; n++, i++, wraparound_section(ic, &i)) {
+#ifndef INTERNAL_VERIFY
+		if (unlikely(from_replay))
+#endif
+			rw_section_mac(ic, i, false);
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je = access_journal_entry(ic, i, j);
+			sector_t sec, area, offset;
+			unsigned k, l, next_loop;
+			sector_t metadata_block;
+			unsigned metadata_offset;
+			struct journal_io *io;
+
+			if (journal_entry_is_unused(je))
+				continue;
+			BUG_ON(unlikely(journal_entry_is_inprogress(je)) && !from_replay);
+			sec = journal_entry_get_sector(je);
+			if (unlikely(from_replay)) {
+				if (unlikely(sec & (unsigned)(ic->sectors_per_block - 1))) {
+					dm_integrity_io_error(ic, "invalid sector in journal", -EIO);
+					sec &= ~(sector_t)(ic->sectors_per_block - 1);
+				}
+			}
+			get_area_and_offset(ic, sec, &area, &offset);
+			restore_last_bytes(ic, access_journal_data(ic, i, j), je);
+			for (k = j + 1; k < ic->journal_section_entries; k++) {
+				struct journal_entry *je2 = access_journal_entry(ic, i, k);
+				sector_t sec2, area2, offset2;
+				if (journal_entry_is_unused(je2))
+					break;
+				BUG_ON(unlikely(journal_entry_is_inprogress(je2)) && !from_replay);
+				sec2 = journal_entry_get_sector(je2);
+				get_area_and_offset(ic, sec2, &area2, &offset2);
+				if (area2 != area || offset2 != offset + ((k - j) << ic->sb->log2_sectors_per_block))
+					break;
+				restore_last_bytes(ic, access_journal_data(ic, i, k), je2);
+			}
+			next_loop = k - 1;
+
+			io = mempool_alloc(ic->journal_io_mempool, GFP_NOIO);
+			io->comp = &comp;
+			io->range.logical_sector = sec;
+			io->range.n_sectors = (k - j) << ic->sb->log2_sectors_per_block;
+
+			spin_lock_irq(&ic->endio_wait.lock);
+			while (unlikely(!add_new_range(ic, &io->range)))
+				sleep_on_endio_wait(ic);
+
+			if (likely(!from_replay)) {
+				struct journal_node *section_node = &ic->journal_tree[i * ic->journal_section_entries];
+
+				/* don't write if there is newer committed sector */
+				while (j < k && find_newer_committed_node(ic, &section_node[j])) {
+					struct journal_entry *je2 = access_journal_entry(ic, i, j);
+
+					journal_entry_set_unused(je2);
+					remove_journal_node(ic, &section_node[j]);
+					j++;
+					sec += ic->sectors_per_block;
+					offset += ic->sectors_per_block;
+				}
+				while (j < k && find_newer_committed_node(ic, &section_node[k - 1])) {
+					struct journal_entry *je2 = access_journal_entry(ic, i, k - 1);
+
+					journal_entry_set_unused(je2);
+					remove_journal_node(ic, &section_node[k - 1]);
+					k--;
+				}
+				if (j == k) {
+					remove_range_unlocked(ic, &io->range);
+					spin_unlock_irq(&ic->endio_wait.lock);
+					mempool_free(io, ic->journal_io_mempool);
+					goto skip_io;
+				}
+				for (l = j; l < k; l++) {
+					remove_journal_node(ic, &section_node[l]);
+				}
+			}
+			spin_unlock_irq(&ic->endio_wait.lock);
+
+			metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
+			for (l = j; l < k; l++) {
+				int r;
+				struct journal_entry *je2 = access_journal_entry(ic, i, l);
+
+				if (
+#ifndef INTERNAL_VERIFY
+				    unlikely(from_replay) &&
+#endif
+				    ic->internal_hash) {
+					char test_tag[max(crypto_shash_digestsize(ic->internal_hash), ic->tag_size)];
+
+					integrity_sector_checksum(ic, sec + ((l - j) << ic->sb->log2_sectors_per_block),
+								  (char *)access_journal_data(ic, i, l), test_tag);
+					if (unlikely(memcmp(test_tag, journal_entry_tag(ic, je2), ic->tag_size)))
+						dm_integrity_io_error(ic, "tag mismatch when replaying journal", -EILSEQ);
+				}
+
+				journal_entry_set_unused(je2);
+				r = dm_integrity_rw_tag(ic, journal_entry_tag(ic, je2), &metadata_block, &metadata_offset,
+							ic->tag_size, TAG_WRITE);
+				if (unlikely(r)) {
+					dm_integrity_io_error(ic, "reading tags", r);
+				}
+			}
+
+			atomic_inc(&comp.in_flight);
+			copy_from_journal(ic, i, j << ic->sb->log2_sectors_per_block,
+					  (k - j) << ic->sb->log2_sectors_per_block,
+					  get_data_sector(ic, area, offset),
+					  complete_copy_from_journal, io);
+skip_io:
+			j = next_loop;
+		}
+	}
+
+	dm_bufio_write_dirty_buffers_async(ic->bufio);
+
+	complete_journal_op(&comp);
+	wait_for_completion_io(&comp.comp);
+
+	dm_integrity_flush_buffers(ic);
+}
+
+static void integrity_writer(struct work_struct *w)
+{
+	struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, writer_work);
+	unsigned write_start, write_sections;
+
+	unsigned prev_free_sectors;
+
+	/* the following test is not needed, but it tests the replay code */
+	if (ACCESS_ONCE(ic->suspending))
+		return;
+
+	spin_lock_irq(&ic->endio_wait.lock);
+	write_start = ic->committed_section;
+	write_sections = ic->n_committed_sections;
+	spin_unlock_irq(&ic->endio_wait.lock);
+
+	if (!write_sections)
+		return;
+
+	do_journal_write(ic, write_start, write_sections, false);
+
+	spin_lock_irq(&ic->endio_wait.lock);
+
+	ic->committed_section += write_sections;
+	wraparound_section(ic, &ic->committed_section);
+	ic->n_committed_sections -= write_sections;
+
+	prev_free_sectors = ic->free_sectors;
+	ic->free_sectors += write_sections * ic->journal_section_entries;
+	if (unlikely(!prev_free_sectors))
+		wake_up_locked(&ic->endio_wait);
+
+	spin_unlock_irq(&ic->endio_wait.lock);
+}
+
+static void init_journal(struct dm_integrity_c *ic, unsigned start_section,
+			 unsigned n_sections, unsigned char commit_seq)
+{
+	unsigned i, j, n;
+
+	if (!n_sections)
+		return;
+
+	for (n = 0; n < n_sections; n++) {
+		i = start_section + n;
+		wraparound_section(ic, &i);
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js = access_journal(ic, i, j);
+			memset(&js->entries, 0, JOURNAL_SECTOR_DATA);
+			js->commit_id = dm_integrity_commit_id(ic, i, j, commit_seq);
+		}
+		for (j = 0; j < ic->journal_section_entries; j++) {
+			struct journal_entry *je = access_journal_entry(ic, i, j);
+			journal_entry_set_unused(je);
+		}
+	}
+
+	write_journal(ic, start_section, n_sections);
+}
+
+static int find_commit_seq(struct dm_integrity_c *ic, unsigned i, unsigned j, commit_id_t id)
+{
+	unsigned char k;
+	for (k = 0; k < N_COMMIT_IDS; k++) {
+		if (dm_integrity_commit_id(ic, i, j, k) == id)
+			return k;
+	}
+	dm_integrity_io_error(ic, "journal commit id", -EIO);
+	return -EIO;
+}
+
+static void replay_journal(struct dm_integrity_c *ic)
+{
+	unsigned i, j;
+	bool used_commit_ids[N_COMMIT_IDS];
+	unsigned max_commit_id_sections[N_COMMIT_IDS];
+	unsigned write_start, write_sections;
+	unsigned continue_section;
+	bool journal_empty;
+	unsigned char unused, last_used, want_commit_seq;
+
+	if (ic->mode == 'R')
+		return;
+
+	if (ic->journal_uptodate)
+		return;
+
+	last_used = 0;
+	write_start = 0;
+
+	if (!ic->just_formatted) {
+		DEBUG_print("reading journal\n");
+		rw_journal(ic, REQ_OP_READ, 0, 0, ic->journal_sections, NULL);
+		if (ic->journal_io)
+			DEBUG_bytes(lowmem_page_address(ic->journal_io[0].page), 64, "read journal");
+		if (ic->journal_io) {
+			struct journal_completion crypt_comp;
+			crypt_comp.ic = ic;
+			crypt_comp.comp = COMPLETION_INITIALIZER_ONSTACK(crypt_comp.comp);
+			crypt_comp.in_flight = (atomic_t)ATOMIC_INIT(0);
+			encrypt_journal(ic, false, 0, ic->journal_sections, &crypt_comp);
+			wait_for_completion(&crypt_comp.comp);
+		}
+		DEBUG_bytes(lowmem_page_address(ic->journal[0].page), 64, "decrypted journal");
+	}
+
+	if (dm_integrity_failed(ic))
+		goto clear_journal;
+
+	journal_empty = true;
+	memset(used_commit_ids, 0, sizeof used_commit_ids);
+	memset(max_commit_id_sections, 0, sizeof max_commit_id_sections);
+	for (i = 0; i < ic->journal_sections; i++) {
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			int k;
+			struct journal_sector *js = access_journal(ic, i, j);
+			k = find_commit_seq(ic, i, j, js->commit_id);
+			if (k < 0)
+				goto clear_journal;
+			used_commit_ids[k] = true;
+			max_commit_id_sections[k] = i;
+		}
+		if (journal_empty) {
+			for (j = 0; j < ic->journal_section_entries; j++) {
+				struct journal_entry *je = access_journal_entry(ic, i, j);
+				if (!journal_entry_is_unused(je)) {
+					journal_empty = false;
+					break;
+				}
+			}
+		}
+	}
+
+	if (!used_commit_ids[N_COMMIT_IDS - 1]) {
+		unused = N_COMMIT_IDS - 1;
+		while (unused && !used_commit_ids[unused - 1])
+			unused--;
+	} else {
+		for (unused = 0; unused < N_COMMIT_IDS; unused++)
+			if (!used_commit_ids[unused])
+				break;
+		if (unused == N_COMMIT_IDS) {
+			dm_integrity_io_error(ic, "journal commit ids", -EIO);
+			goto clear_journal;
+		}
+	}
+	DEBUG_print("first unused commit seq %d [%d,%d,%d,%d]\n",
+		    unused, used_commit_ids[0], used_commit_ids[1],
+		    used_commit_ids[2], used_commit_ids[3]);
+
+	last_used = prev_commit_seq(unused);
+	want_commit_seq = prev_commit_seq(last_used);
+
+	if (!used_commit_ids[want_commit_seq] && used_commit_ids[prev_commit_seq(want_commit_seq)])
+		journal_empty = true;
+
+	write_start = max_commit_id_sections[last_used] + 1;
+	if (unlikely(write_start >= ic->journal_sections))
+		want_commit_seq = next_commit_seq(want_commit_seq);
+	wraparound_section(ic, &write_start);
+
+	i = write_start;
+	for (write_sections = 0; write_sections < ic->journal_sections; write_sections++) {
+		for (j = 0; j < ic->journal_section_sectors; j++) {
+			struct journal_sector *js = access_journal(ic, i, j);
+
+			if (js->commit_id != dm_integrity_commit_id(ic, i, j, want_commit_seq)) {
+				/*
+				 * This could be caused by crash during writing.
+				 * We won't replay the inconsistent part of the
+				 * journal.
+				 */
+				DEBUG_print("commit id mismatch at position (%u, %u): %d != %d\n",
+					    i, j, find_commit_seq(ic, i, j, js->commit_id), want_commit_seq);
+				goto brk;
+			}
+		}
+		i++;
+		if (unlikely(i >= ic->journal_sections))
+			want_commit_seq = next_commit_seq(want_commit_seq);
+		wraparound_section(ic, &i);
+	}
+brk:
+
+	if (!journal_empty) {
+		DEBUG_print("replaying %u sections, starting at %u, commit seq %d\n",
+			    write_sections, write_start, want_commit_seq);
+		do_journal_write(ic, write_start, write_sections, true);
+	}
+
+	if (write_sections == ic->journal_sections && (ic->mode == 'J' || journal_empty)) {
+		continue_section = write_start;
+		ic->commit_seq = want_commit_seq;
+		DEBUG_print("continuing from section %u, commit seq %d\n", write_start, ic->commit_seq);
+	} else {
+		unsigned s;
+		unsigned char erase_seq;
+clear_journal:
+		DEBUG_print("clearing journal\n");
+
+		erase_seq = prev_commit_seq(prev_commit_seq(last_used));
+		s = write_start;
+		init_journal(ic, s, 1, erase_seq);
+		s++;
+		wraparound_section(ic, &s);
+		if (ic->journal_sections >= 2) {
+			init_journal(ic, s, ic->journal_sections - 2, erase_seq);
+			s += ic->journal_sections - 2;
+			wraparound_section(ic, &s);
+			init_journal(ic, s, 1, erase_seq);
+		}
+
+		continue_section = 0;
+		ic->commit_seq = next_commit_seq(erase_seq);
+	}
+
+	ic->committed_section = continue_section;
+	ic->n_committed_sections = 0;
+
+	ic->uncommitted_section = continue_section;
+	ic->n_uncommitted_sections = 0;
+
+	ic->free_section = continue_section;
+	ic->free_section_entry = 0;
+	ic->free_sectors = ic->journal_entries;
+
+	ic->journal_tree_root = RB_ROOT;
+	for (i = 0; i < ic->journal_entries; i++)
+		init_journal_node(&ic->journal_tree[i]);
+}
+
+static void dm_integrity_postsuspend(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+
+	del_timer_sync(&ic->autocommit_timer);
+
+	ic->suspending = true;
+
+	queue_work(ic->commit_wq, &ic->commit_work);
+	drain_workqueue(ic->commit_wq);
+
+	if (ic->mode == 'J') {
+		drain_workqueue(ic->writer_wq);
+		dm_integrity_flush_buffers(ic);
+	}
+
+	ic->suspending = false;
+
+	BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
+
+	ic->journal_uptodate = true;
+}
+
+static void dm_integrity_resume(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+
+	replay_journal(ic);
+}
+
+static void dm_integrity_status(struct dm_target *ti, status_type_t type,
+				unsigned status_flags, char *result, unsigned maxlen)
+{
+	struct dm_integrity_c *ic = (struct dm_integrity_c *)ti->private;
+	unsigned arg_count;
+	size_t sz = 0;
+
+	switch (type) {
+	case STATUSTYPE_INFO:
+		result[0] = '\0';
+		break;
+
+	case STATUSTYPE_TABLE: {
+		__u64 watermark_percentage = (__u64)(ic->journal_entries - ic->free_sectors_threshold) * 100;
+		watermark_percentage += ic->journal_entries / 2;
+		do_div(watermark_percentage, ic->journal_entries);
+		arg_count = 5;
+		arg_count += ic->sectors_per_block != 1;
+		arg_count += !!ic->internal_hash_alg.alg_string;
+		arg_count += !!ic->journal_crypt_alg.alg_string;
+		arg_count += !!ic->journal_mac_alg.alg_string;
+		DMEMIT("%s %llu %u %c %u", ic->dev->name, (unsigned long long)ic->start,
+		       ic->tag_size, ic->mode, arg_count);
+		DMEMIT(" journal_sectors:%u", ic->initial_sectors - SB_SECTORS);
+		DMEMIT(" interleave_sectors:%u", 1U << ic->sb->log2_interleave_sectors);
+		DMEMIT(" buffer_sectors:%u", 1U << ic->log2_buffer_sectors);
+		DMEMIT(" journal_watermark:%u", (unsigned)watermark_percentage);
+		DMEMIT(" commit_time:%u", ic->autocommit_msec);
+		if (ic->sectors_per_block != 1)
+			DMEMIT(" block_size:%u", ic->sectors_per_block << SECTOR_SHIFT);
+
+#define EMIT_ALG(a, n)							\
+		do {							\
+			if (ic->a.alg_string) {				\
+				DMEMIT(" %s:%s", n, ic->a.alg_string);	\
+				if (ic->a.key_string)			\
+					DMEMIT(":%s", ic->a.key_string);\
+			}						\
+		} while (0)
+		EMIT_ALG(internal_hash_alg, "internal_hash");
+		EMIT_ALG(journal_crypt_alg, "journal_crypt");
+		EMIT_ALG(journal_mac_alg, "journal_mac");
+		break;
+	}
+	}
+}
+
+static int dm_integrity_iterate_devices(struct dm_target *ti,
+					iterate_devices_callout_fn fn, void *data)
+{
+	struct dm_integrity_c *ic = ti->private;
+
+	return fn(ti, ic->dev, ic->start + ic->initial_sectors + ic->metadata_run, ti->len, data);
+}
+
+static void dm_integrity_io_hints(struct dm_target *ti, struct queue_limits *limits)
+{
+	struct dm_integrity_c *ic = ti->private;
+
+	if (ic->sectors_per_block > 1) {
+		limits->logical_block_size = ic->sectors_per_block << SECTOR_SHIFT;
+		limits->physical_block_size = ic->sectors_per_block << SECTOR_SHIFT;
+		blk_limits_io_min(limits, ic->sectors_per_block << SECTOR_SHIFT);
+	}
+}
+
+static void calculate_journal_section_size(struct dm_integrity_c *ic)
+{
+	unsigned sector_space = JOURNAL_SECTOR_DATA;
+
+	ic->journal_sections = le32_to_cpu(ic->sb->journal_sections);
+	ic->journal_entry_size = roundup(offsetof(struct journal_entry, last_bytes[ic->sectors_per_block]) + ic->tag_size,
+					 JOURNAL_ENTRY_ROUNDUP);
+
+	if (ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC))
+		sector_space -= JOURNAL_MAC_PER_SECTOR;
+	ic->journal_entries_per_sector = sector_space / ic->journal_entry_size;
+	ic->journal_section_entries = ic->journal_entries_per_sector * JOURNAL_BLOCK_SECTORS;
+	ic->journal_section_sectors = (ic->journal_section_entries << ic->sb->log2_sectors_per_block) + JOURNAL_BLOCK_SECTORS;
+	ic->journal_entries = ic->journal_section_entries * ic->journal_sections;
+}
+
+static int calculate_device_limits(struct dm_integrity_c *ic)
+{
+	__u64 initial_sectors;
+	sector_t last_sector, last_area, last_offset;
+
+	calculate_journal_section_size(ic);
+	initial_sectors = SB_SECTORS + (__u64)ic->journal_section_sectors * ic->journal_sections;
+	if (initial_sectors + METADATA_PADDING_SECTORS >= ic->device_sectors || initial_sectors > UINT_MAX)
+		return -EINVAL;
+	ic->initial_sectors = initial_sectors;
+
+	ic->metadata_run = roundup((__u64)ic->tag_size << (ic->sb->log2_interleave_sectors - ic->sb->log2_sectors_per_block),
+				   (__u64)(1 << SECTOR_SHIFT << METADATA_PADDING_SECTORS)) >> SECTOR_SHIFT;
+	if (!(ic->metadata_run & (ic->metadata_run - 1)))
+		ic->log2_metadata_run = __ffs(ic->metadata_run);
+	else
+		ic->log2_metadata_run = -1;
+
+	get_area_and_offset(ic, ic->provided_data_sectors - 1, &last_area, &last_offset);
+	last_sector = get_data_sector(ic, last_area, last_offset);
+
+	if (ic->start + last_sector < last_sector || ic->start + last_sector >= ic->device_sectors)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sectors, unsigned interleave_sectors)
+{
+	unsigned journal_sections;
+	int test_bit;
+
+	memset(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT);
+	memcpy(ic->sb->magic, SB_MAGIC, 8);
+	ic->sb->version = SB_VERSION;
+	ic->sb->integrity_tag_size = cpu_to_le16(ic->tag_size);
+	ic->sb->log2_sectors_per_block = __ffs(ic->sectors_per_block);
+	if (ic->journal_mac_alg.alg_string)
+		ic->sb->flags |= cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC);
+
+	calculate_journal_section_size(ic);
+	journal_sections = journal_sectors / ic->journal_section_sectors;
+	if (!journal_sections)
+		journal_sections = 1;
+	ic->sb->journal_sections = cpu_to_le32(journal_sections);
+
+	if (!interleave_sectors)
+		interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
+	ic->sb->log2_interleave_sectors = __fls(interleave_sectors);
+	ic->sb->log2_interleave_sectors = max((__u8)MIN_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
+	ic->sb->log2_interleave_sectors = min((__u8)MAX_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
+
+	ic->provided_data_sectors = 0;
+	for (test_bit = fls64(ic->device_sectors) - 1; test_bit >= 3; test_bit--) {
+		__u64 prev_data_sectors = ic->provided_data_sectors;
+
+		ic->provided_data_sectors |= (sector_t)1 << test_bit;
+		if (calculate_device_limits(ic))
+			ic->provided_data_sectors = prev_data_sectors;
+	}
+
+	if (!ic->provided_data_sectors)
+		return -EINVAL;
+
+	ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
+
+	return 0;
+}
+
+static void dm_integrity_set(struct dm_target *ti, struct dm_integrity_c *ic)
+{
+	struct gendisk *disk = dm_disk(dm_table_get_md(ti->table));
+	struct blk_integrity bi;
+
+	memset(&bi, 0, sizeof(bi));
+	bi.profile = &dm_integrity_profile;
+	bi.tuple_size = ic->tag_size;
+	bi.tag_size = bi.tuple_size;
+	bi.interval_exp = ic->sb->log2_sectors_per_block + SECTOR_SHIFT;
+
+	blk_integrity_register(disk, &bi);
+	blk_queue_max_integrity_segments(disk->queue, UINT_MAX);
+}
+
+/* FIXME: use new kvmalloc */
+static void *dm_integrity_kvmalloc(size_t size, gfp_t gfp)
+{
+	void *ptr = NULL;
+
+	if (size <= PAGE_SIZE)
+		ptr = kmalloc(size, GFP_KERNEL | gfp);
+	if (!ptr && size <= KMALLOC_MAX_SIZE)
+		ptr = kmalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | gfp);
+	if (!ptr)
+		ptr = __vmalloc(size, GFP_KERNEL | gfp, PAGE_KERNEL);
+
+	return ptr;
+}
+
+static void dm_integrity_free_page_list(struct dm_integrity_c *ic, struct page_list *pl)
+{
+	unsigned i;
+
+	if (!pl)
+		return;
+	for (i = 0; i < ic->journal_pages; i++)
+		if (pl[i].page)
+			__free_page(pl[i].page);
+	kvfree(pl);
+}
+
+static struct page_list *dm_integrity_alloc_page_list(struct dm_integrity_c *ic)
+{
+	size_t page_list_desc_size = ic->journal_pages * sizeof(struct page_list);
+	struct page_list *pl;
+	unsigned i;
+
+	pl = dm_integrity_kvmalloc(page_list_desc_size, __GFP_ZERO);
+	if (!pl)
+		return NULL;
+
+	for (i = 0; i < ic->journal_pages; i++) {
+		pl[i].page = alloc_page(GFP_KERNEL);
+		if (!pl[i].page) {
+			dm_integrity_free_page_list(ic, pl);
+			return NULL;
+		}
+		if (i)
+			pl[i - 1].next = &pl[i];
+	}
+
+	return pl;
+}
+
+static void dm_integrity_free_journal_scatterlist(struct dm_integrity_c *ic, struct scatterlist **sl)
+{
+	unsigned i;
+	for (i = 0; i < ic->journal_sections; i++)
+		kvfree(sl[i]);
+	kfree(sl);
+}
+
+static struct scatterlist **dm_integrity_alloc_journal_scatterlist(struct dm_integrity_c *ic, struct page_list *pl)
+{
+	struct scatterlist **sl;
+	unsigned i;
+
+	sl = dm_integrity_kvmalloc(ic->journal_sections * sizeof(struct scatterlist *), __GFP_ZERO);
+	if (!sl)
+		return NULL;
+
+	for (i = 0; i < ic->journal_sections; i++) {
+		struct scatterlist *s;
+		unsigned start_index, start_offset;
+		unsigned end_index, end_offset;
+		unsigned n_pages;
+		unsigned idx;
+
+		page_list_location(ic, i, 0, &start_index, &start_offset);
+		page_list_location(ic, i, ic->journal_section_sectors - 1, &end_index, &end_offset);
+
+		n_pages = (end_index - start_index + 1);
+
+		s = dm_integrity_kvmalloc(n_pages * sizeof(struct scatterlist), 0);
+		if (!s) {
+			dm_integrity_free_journal_scatterlist(ic, sl);
+			return NULL;
+		}
+
+		sg_init_table(s, n_pages);
+		for (idx = start_index; idx <= end_index; idx++) {
+			char *va = lowmem_page_address(pl[idx].page);
+			unsigned start = 0, end = PAGE_SIZE;
+			if (idx == start_index)
+				start = start_offset;
+			if (idx == end_index)
+				end = end_offset + (1 << SECTOR_SHIFT);
+			sg_set_buf(&s[idx - start_index], va + start, end - start);
+		}
+
+		sl[i] = s;
+	}
+
+	return sl;
+}
+
+static void free_alg(struct alg_spec *a)
+{
+	kzfree(a->alg_string);
+	kzfree(a->key);
+	memset(a, 0, sizeof *a);
+}
+
+static int get_alg_and_key(const char *arg, struct alg_spec *a, char **error, char *error_inval)
+{
+	char *k;
+
+	free_alg(a);
+
+	a->alg_string = kstrdup(strchr(arg, ':') + 1, GFP_KERNEL);
+	if (!a->alg_string)
+		goto nomem;
+
+	k = strchr(a->alg_string, ':');
+	if (k) {
+		*k = 0;
+		a->key_string = k + 1;
+		if (strlen(a->key_string) & 1)
+			goto inval;
+
+		a->key_size = strlen(a->key_string) / 2;
+		a->key = kmalloc(a->key_size, GFP_KERNEL);
+		if (!a->key)
+			goto nomem;
+		if (hex2bin(a->key, a->key_string, a->key_size))
+			goto inval;
+	}
+
+	return 0;
+inval:
+	*error = error_inval;
+	return -EINVAL;
+nomem:
+	*error = "Out of memory for an argument";
+	return -ENOMEM;
+}
+
+static int get_mac(struct crypto_shash **hash, struct alg_spec *a, char **error,
+		   char *error_alg, char *error_key)
+{
+	int r;
+
+	if (a->alg_string) {
+		*hash = crypto_alloc_shash(a->alg_string, 0, CRYPTO_ALG_ASYNC);
+		if (IS_ERR(*hash)) {
+			*error = error_alg;
+			r = PTR_ERR(*hash);
+			*hash = NULL;
+			return r;
+		}
+
+		if (a->key) {
+			r = crypto_shash_setkey(*hash, a->key, a->key_size);
+			if (r) {
+				*error = error_key;
+				return r;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int create_journal(struct dm_integrity_c *ic, char **error)
+{
+	int r = 0;
+	unsigned i;
+	__u64 journal_pages, journal_desc_size, journal_tree_size;
+	unsigned char *crypt_data = NULL;
+
+	ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL);
+	ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL);
+	ic->commit_ids[2] = cpu_to_le64(0x3333333333333333ULL);
+	ic->commit_ids[3] = cpu_to_le64(0x4444444444444444ULL);
+
+	journal_pages = roundup((__u64)ic->journal_sections * ic->journal_section_sectors,
+				PAGE_SIZE >> SECTOR_SHIFT) >> (PAGE_SHIFT - SECTOR_SHIFT);
+	journal_desc_size = journal_pages * sizeof(struct page_list);
+	if (journal_pages >= totalram_pages - totalhigh_pages || journal_desc_size > ULONG_MAX) {
+		*error = "Journal doesn't fit into memory";
+		r = -ENOMEM;
+		goto bad;
+	}
+	ic->journal_pages = journal_pages;
+
+	ic->journal = dm_integrity_alloc_page_list(ic);
+	if (!ic->journal) {
+		*error = "Could not allocate memory for journal";
+		r = -ENOMEM;
+		goto bad;
+	}
+	if (ic->journal_crypt_alg.alg_string) {
+		unsigned ivsize, blocksize;
+		struct journal_completion comp;
+
+		comp.ic = ic;
+		ic->journal_crypt = crypto_alloc_skcipher(ic->journal_crypt_alg.alg_string, 0, 0);
+		if (IS_ERR(ic->journal_crypt)) {
+			*error = "Invalid journal cipher";
+			r = PTR_ERR(ic->journal_crypt);
+			ic->journal_crypt = NULL;
+			goto bad;
+		}
+		ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
+		blocksize = crypto_skcipher_blocksize(ic->journal_crypt);
+
+		if (ic->journal_crypt_alg.key) {
+			r = crypto_skcipher_setkey(ic->journal_crypt, ic->journal_crypt_alg.key,
+						   ic->journal_crypt_alg.key_size);
+			if (r) {
+				*error = "Error setting encryption key";
+				goto bad;
+			}
+		}
+		DEBUG_print("cipher %s, block size %u iv size %u\n",
+			    ic->journal_crypt_alg.alg_string, blocksize, ivsize);
+
+		ic->journal_io = dm_integrity_alloc_page_list(ic);
+		if (!ic->journal_io) {
+			*error = "Could not allocate memory for journal io";
+			r = -ENOMEM;
+			goto bad;
+		}
+
+		if (blocksize == 1) {
+			struct scatterlist *sg;
+			SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt);
+			unsigned char iv[ivsize];
+			skcipher_request_set_tfm(req, ic->journal_crypt);
+
+			ic->journal_xor = dm_integrity_alloc_page_list(ic);
+			if (!ic->journal_xor) {
+				*error = "Could not allocate memory for journal xor";
+				r = -ENOMEM;
+				goto bad;
+			}
+
+			sg = dm_integrity_kvmalloc((ic->journal_pages + 1) * sizeof(struct scatterlist), 0);
+			if (!sg) {
+				*error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			sg_init_table(sg, ic->journal_pages + 1);
+			for (i = 0; i < ic->journal_pages; i++) {
+				char *va = lowmem_page_address(ic->journal_xor[i].page);
+				clear_page(va);
+				sg_set_buf(&sg[i], va, PAGE_SIZE);
+			}
+			sg_set_buf(&sg[i], &ic->commit_ids, sizeof ic->commit_ids);
+			memset(iv, 0x00, ivsize);
+
+			skcipher_request_set_crypt(req, sg, sg, PAGE_SIZE * ic->journal_pages + sizeof ic->commit_ids, iv);
+			comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+			comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+			if (do_crypt(true, req, &comp))
+				wait_for_completion(&comp.comp);
+			kvfree(sg);
+			r = dm_integrity_failed(ic);
+			if (r) {
+				*error = "Unable to encrypt journal";
+				goto bad;
+			}
+			DEBUG_bytes(lowmem_page_address(ic->journal_xor[0].page), 64, "xor data");
+
+			crypto_free_skcipher(ic->journal_crypt);
+			ic->journal_crypt = NULL;
+		} else {
+			SKCIPHER_REQUEST_ON_STACK(req, ic->journal_crypt);
+			unsigned char iv[ivsize];
+			unsigned crypt_len = roundup(ivsize, blocksize);
+
+			crypt_data = kmalloc(crypt_len, GFP_KERNEL);
+			if (!crypt_data) {
+				*error = "Unable to allocate crypt data";
+				r = -ENOMEM;
+				goto bad;
+			}
+
+			skcipher_request_set_tfm(req, ic->journal_crypt);
+
+			ic->journal_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal);
+			if (!ic->journal_scatterlist) {
+				*error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			ic->journal_io_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal_io);
+			if (!ic->journal_io_scatterlist) {
+				*error = "Unable to allocate sg list";
+				r = -ENOMEM;
+				goto bad;
+			}
+			ic->sk_requests = dm_integrity_kvmalloc(ic->journal_sections * sizeof(struct skcipher_request *), __GFP_ZERO);
+			if (!ic->sk_requests) {
+				*error = "Unable to allocate sk requests";
+				r = -ENOMEM;
+				goto bad;
+			}
+			for (i = 0; i < ic->journal_sections; i++) {
+				struct scatterlist sg;
+				struct skcipher_request *section_req;
+				__u32 section_le = cpu_to_le32(i);
+
+				memset(iv, 0x00, ivsize);
+				memset(crypt_data, 0x00, crypt_len);
+				memcpy(crypt_data, &section_le, min((size_t)crypt_len, sizeof(section_le)));
+
+				sg_init_one(&sg, crypt_data, crypt_len);
+				skcipher_request_set_crypt(req, &sg, &sg, crypt_len, iv);
+				comp.comp = COMPLETION_INITIALIZER_ONSTACK(comp.comp);
+				comp.in_flight = (atomic_t)ATOMIC_INIT(1);
+				if (do_crypt(true, req, &comp))
+					wait_for_completion(&comp.comp);
+
+				r = dm_integrity_failed(ic);
+				if (r) {
+					*error = "Unable to generate iv";
+					goto bad;
+				}
+
+				section_req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL);
+				if (!section_req) {
+					*error = "Unable to allocate crypt request";
+					r = -ENOMEM;
+					goto bad;
+				}
+				section_req->iv = kmalloc(ivsize * 2, GFP_KERNEL);
+				if (!section_req->iv) {
+					skcipher_request_free(section_req);
+					*error = "Unable to allocate iv";
+					r = -ENOMEM;
+					goto bad;
+				}
+				memcpy(section_req->iv + ivsize, crypt_data, ivsize);
+				section_req->cryptlen = (size_t)ic->journal_section_sectors << SECTOR_SHIFT;
+				ic->sk_requests[i] = section_req;
+				DEBUG_bytes(crypt_data, ivsize, "iv(%u)", i);
+			}
+		}
+	}
+
+	for (i = 0; i < N_COMMIT_IDS; i++) {
+		unsigned j;
+retest_commit_id:
+		for (j = 0; j < i; j++) {
+			if (ic->commit_ids[j] == ic->commit_ids[i]) {
+				ic->commit_ids[i] = cpu_to_le64(le64_to_cpu(ic->commit_ids[i]) + 1);
+				goto retest_commit_id;
+			}
+		}
+		DEBUG_print("commit id %u: %016llx\n", i, ic->commit_ids[i]);
+	}
+
+	journal_tree_size = (__u64)ic->journal_entries * sizeof(struct journal_node);
+	if (journal_tree_size > ULONG_MAX) {
+		*error = "Journal doesn't fit into memory";
+		r = -ENOMEM;
+		goto bad;
+	}
+	ic->journal_tree = dm_integrity_kvmalloc(journal_tree_size, 0);
+	if (!ic->journal_tree) {
+		*error = "Could not allocate memory for journal tree";
+		r = -ENOMEM;
+	}
+bad:
+	kfree(crypt_data);
+	return r;
+}
+
+/*
+ * Construct a integrity mapping
+ *
+ * Arguments:
+ *	device
+ *	offset from the start of the device
+ *	tag size
+ *	D - direct writes, J - journal writes, R - recovery mode
+ *	number of optional arguments
+ *	optional arguments:
+ *		journal_sectors
+ *		interleave_sectors
+ *		buffer_sectors
+ *		journal_watermark
+ *		commit_time
+ *		internal_hash
+ *		journal_crypt
+ *		journal_mac
+ *		block_size
+ */
+static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
+{
+	struct dm_integrity_c *ic;
+	char dummy;
+	int r;
+	unsigned extra_args;
+	struct dm_arg_set as;
+	static struct dm_arg _args[] = {
+		{0, 9, "Invalid number of feature args"},
+	};
+	unsigned journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec;
+	bool should_write_sb;
+	__u64 threshold;
+	unsigned long long start;
+
+#define DIRECT_ARGUMENTS	4
+
+	if (argc <= DIRECT_ARGUMENTS) {
+		ti->error = "Invalid argument count";
+		return -EINVAL;
+	}
+
+	ic = kzalloc(sizeof(struct dm_integrity_c), GFP_KERNEL);
+	if (!ic) {
+		ti->error = "Cannot allocate integrity context";
+		return -ENOMEM;
+	}
+	ti->private = ic;
+	ti->per_io_data_size = sizeof(struct dm_integrity_io);
+
+	ic->in_progress = RB_ROOT;
+	init_waitqueue_head(&ic->endio_wait);
+	bio_list_init(&ic->flush_bio_list);
+	init_waitqueue_head(&ic->copy_to_journal_wait);
+	init_completion(&ic->crypto_backoff);
+
+	r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &ic->dev);
+	if (r) {
+		ti->error = "Device lookup failed";
+		goto bad;
+	}
+
+	if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {
+		ti->error = "Invalid starting offset";
+		r = -EINVAL;
+		goto bad;
+	}
+	ic->start = start;
+
+	if (strcmp(argv[2], "-")) {
+		if (sscanf(argv[2], "%u%c", &ic->tag_size, &dummy) != 1 || !ic->tag_size) {
+			ti->error = "Invalid tag size";
+			r = -EINVAL;
+			goto bad;
+		}
+	}
+
+	if (!strcmp(argv[3], "J") || !strcmp(argv[3], "D") || !strcmp(argv[3], "R"))
+		ic->mode = argv[3][0];
+	else {
+		ti->error = "Invalid mode (expecting J, D, R)";
+		r = -EINVAL;
+		goto bad;
+	}
+
+	ic->device_sectors = i_size_read(ic->dev->bdev->bd_inode) >> SECTOR_SHIFT;
+	journal_sectors = min((sector_t)DEFAULT_MAX_JOURNAL_SECTORS,
+			ic->device_sectors >> DEFAULT_JOURNAL_SIZE_FACTOR);
+	interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
+	buffer_sectors = DEFAULT_BUFFER_SECTORS;
+	journal_watermark = DEFAULT_JOURNAL_WATERMARK;
+	sync_msec = DEFAULT_SYNC_MSEC;
+	ic->sectors_per_block = 1;
+
+	as.argc = argc - DIRECT_ARGUMENTS;
+	as.argv = argv + DIRECT_ARGUMENTS;
+	r = dm_read_arg_group(_args, &as, &extra_args, &ti->error);
+	if (r)
+		goto bad;
+
+	while (extra_args--) {
+		const char *opt_string;
+		unsigned val;
+		opt_string = dm_shift_arg(&as);
+		if (!opt_string) {
+			r = -EINVAL;
+			ti->error = "Not enough feature arguments";
+			goto bad;
+		}
+		if (sscanf(opt_string, "journal_sectors:%u%c", &val, &dummy) == 1)
+			journal_sectors = val;
+		else if (sscanf(opt_string, "interleave_sectors:%u%c", &val, &dummy) == 1)
+			interleave_sectors = val;
+		else if (sscanf(opt_string, "buffer_sectors:%u%c", &val, &dummy) == 1)
+			buffer_sectors = val;
+		else if (sscanf(opt_string, "journal_watermark:%u%c", &val, &dummy) == 1 && val <= 100)
+			journal_watermark = val;
+		else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1)
+			sync_msec = val;
+		else if (sscanf(opt_string, "block_size:%u%c", &val, &dummy) == 1) {
+			if (val < 1 << SECTOR_SHIFT ||
+			    val > MAX_SECTORS_PER_BLOCK << SECTOR_SHIFT ||
+			    (val & (val -1))) {
+				r = -EINVAL;
+				ti->error = "Invalid block_size argument";
+				goto bad;
+			}
+			ic->sectors_per_block = val >> SECTOR_SHIFT;
+		} else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
+			r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
+					    "Invalid internal_hash argument");
+			if (r)
+				goto bad;
+		} else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
+			r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
+					    "Invalid journal_crypt argument");
+			if (r)
+				goto bad;
+		} else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
+			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
+					    "Invalid journal_mac argument");
+			if (r)
+				goto bad;
+		} else {
+			r = -EINVAL;
+			ti->error = "Invalid argument";
+			goto bad;
+		}
+	}
+
+	r = get_mac(&ic->internal_hash, &ic->internal_hash_alg, &ti->error,
+		    "Invalid internal hash", "Error setting internal hash key");
+	if (r)
+		goto bad;
+
+	r = get_mac(&ic->journal_mac, &ic->journal_mac_alg, &ti->error,
+		    "Invalid journal mac", "Error setting journal mac key");
+	if (r)
+		goto bad;
+
+	if (!ic->tag_size) {
+		if (!ic->internal_hash) {
+			ti->error = "Unknown tag size";
+			r = -EINVAL;
+			goto bad;
+		}
+		ic->tag_size = crypto_shash_digestsize(ic->internal_hash);
+	}
+	if (ic->tag_size > MAX_TAG_SIZE) {
+		ti->error = "Too big tag size";
+		r = -EINVAL;
+		goto bad;
+	}
+	if (!(ic->tag_size & (ic->tag_size - 1)))
+		ic->log2_tag_size = __ffs(ic->tag_size);
+	else
+		ic->log2_tag_size = -1;
+
+	ic->autocommit_jiffies = msecs_to_jiffies(sync_msec);
+	ic->autocommit_msec = sync_msec;
+	setup_timer(&ic->autocommit_timer, autocommit_fn, (unsigned long)ic);
+
+	ic->io = dm_io_client_create();
+	if (IS_ERR(ic->io)) {
+		r = PTR_ERR(ic->io);
+		ic->io = NULL;
+		ti->error = "Cannot allocate dm io";
+		goto bad;
+	}
+
+	ic->journal_io_mempool = mempool_create_slab_pool(JOURNAL_IO_MEMPOOL, journal_io_cache);
+	if (!ic->journal_io_mempool) {
+		r = -ENOMEM;
+		ti->error = "Cannot allocate mempool";
+		goto bad;
+	}
+
+	ic->metadata_wq = alloc_workqueue("dm-integrity-metadata",
+					  WQ_MEM_RECLAIM, METADATA_WORKQUEUE_MAX_ACTIVE);
+	if (!ic->metadata_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	/*
+	 * If this workqueue were percpu, it would cause bio reordering
+	 * and reduced performance.
+	 */
+	ic->wait_wq = alloc_workqueue("dm-integrity-wait", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+	if (!ic->wait_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+
+	ic->commit_wq = alloc_workqueue("dm-integrity-commit", WQ_MEM_RECLAIM, 1);
+	if (!ic->commit_wq) {
+		ti->error = "Cannot allocate workqueue";
+		r = -ENOMEM;
+		goto bad;
+	}
+	INIT_WORK(&ic->commit_work, integrity_commit);
+
+	if (ic->mode == 'J') {
+		ic->writer_wq = alloc_workqueue("dm-integrity-writer", WQ_MEM_RECLAIM, 1);
+		if (!ic->writer_wq) {
+			ti->error = "Cannot allocate workqueue";
+			r = -ENOMEM;
+			goto bad;
+		}
+		INIT_WORK(&ic->writer_work, integrity_writer);
+	}
+
+	ic->sb = alloc_pages_exact(SB_SECTORS << SECTOR_SHIFT, GFP_KERNEL);
+	if (!ic->sb) {
+		r = -ENOMEM;
+		ti->error = "Cannot allocate superblock area";
+		goto bad;
+	}
+
+	r = sync_rw_sb(ic, REQ_OP_READ, 0);
+	if (r) {
+		ti->error = "Error reading superblock";
+		goto bad;
+	}
+	should_write_sb = false;
+	if (memcmp(ic->sb->magic, SB_MAGIC, 8)) {
+		if (ic->mode != 'R') {
+			if (memchr_inv(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT)) {
+				r = -EINVAL;
+				ti->error = "The device is not initialized";
+				goto bad;
+			}
+		}
+
+		r = initialize_superblock(ic, journal_sectors, interleave_sectors);
+		if (r) {
+			ti->error = "Could not initialize superblock";
+			goto bad;
+		}
+		if (ic->mode != 'R')
+			should_write_sb = true;
+	}
+
+	if (ic->sb->version != SB_VERSION) {
+		r = -EINVAL;
+		ti->error = "Unknown version";
+		goto bad;
+	}
+	if (le16_to_cpu(ic->sb->integrity_tag_size) != ic->tag_size) {
+		r = -EINVAL;
+		ti->error = "Tag size doesn't match the information in superblock";
+		goto bad;
+	}
+	if (ic->sb->log2_sectors_per_block != __ffs(ic->sectors_per_block)) {
+		r = -EINVAL;
+		ti->error = "Block size doesn't match the information in superblock";
+		goto bad;
+	}
+	/* make sure that ti->max_io_len doesn't overflow */
+	if (ic->sb->log2_interleave_sectors < MIN_LOG2_INTERLEAVE_SECTORS ||
+	    ic->sb->log2_interleave_sectors > MAX_LOG2_INTERLEAVE_SECTORS) {
+		r = -EINVAL;
+		ti->error = "Invalid interleave_sectors in the superblock";
+		goto bad;
+	}
+	ic->provided_data_sectors = le64_to_cpu(ic->sb->provided_data_sectors);
+	if (ic->provided_data_sectors != le64_to_cpu(ic->sb->provided_data_sectors)) {
+		/* test for overflow */
+		r = -EINVAL;
+		ti->error = "The superblock has 64-bit device size, but the kernel was compiled with 32-bit sectors";
+		goto bad;
+	}
+	if (!!(ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC)) != !!ic->journal_mac_alg.alg_string) {
+		r = -EINVAL;
+		ti->error = "Journal mac mismatch";
+		goto bad;
+	}
+	r = calculate_device_limits(ic);
+	if (r) {
+		ti->error = "The device is too small";
+		goto bad;
+	}
+
+	if (!buffer_sectors)
+		buffer_sectors = 1;
+	ic->log2_buffer_sectors = min3((int)__fls(buffer_sectors), (int)__ffs(ic->metadata_run), 31 - SECTOR_SHIFT);
+
+	threshold = (__u64)ic->journal_entries * (100 - journal_watermark);
+	threshold += 50;
+	do_div(threshold, 100);
+	ic->free_sectors_threshold = threshold;
+
+	DEBUG_print("initialized:\n");
+	DEBUG_print("	integrity_tag_size %u\n", le16_to_cpu(ic->sb->integrity_tag_size));
+	DEBUG_print("	journal_entry_size %u\n", ic->journal_entry_size);
+	DEBUG_print("	journal_entries_per_sector %u\n", ic->journal_entries_per_sector);
+	DEBUG_print("	journal_section_entries %u\n", ic->journal_section_entries);
+	DEBUG_print("	journal_section_sectors %u\n", ic->journal_section_sectors);
+	DEBUG_print("	journal_sections %u\n", (unsigned)le32_to_cpu(ic->sb->journal_sections));
+	DEBUG_print("	journal_entries %u\n", ic->journal_entries);
+	DEBUG_print("	log2_interleave_sectors %d\n", ic->sb->log2_interleave_sectors);
+	DEBUG_print("	device_sectors 0x%llx\n", (unsigned long long)ic->device_sectors);
+	DEBUG_print("	initial_sectors 0x%x\n", ic->initial_sectors);
+	DEBUG_print("	metadata_run 0x%x\n", ic->metadata_run);
+	DEBUG_print("	log2_metadata_run %d\n", ic->log2_metadata_run);
+	DEBUG_print("	provided_data_sectors 0x%llx (%llu)\n", (unsigned long long)ic->provided_data_sectors,
+		    (unsigned long long)ic->provided_data_sectors);
+	DEBUG_print("	log2_buffer_sectors %u\n", ic->log2_buffer_sectors);
+
+	ic->bufio = dm_bufio_client_create(ic->dev->bdev, 1U << (SECTOR_SHIFT + ic->log2_buffer_sectors),
+					   1, 0, NULL, NULL);
+	if (IS_ERR(ic->bufio)) {
+		r = PTR_ERR(ic->bufio);
+		ti->error = "Cannot initialize dm-bufio";
+		ic->bufio = NULL;
+		goto bad;
+	}
+	dm_bufio_set_sector_offset(ic->bufio, ic->start + ic->initial_sectors);
+
+	if (ic->mode != 'R') {
+		r = create_journal(ic, &ti->error);
+		if (r)
+			goto bad;
+	}
+
+	if (should_write_sb) {
+		int r;
+
+		init_journal(ic, 0, ic->journal_sections, 0);
+		r = dm_integrity_failed(ic);
+		if (unlikely(r)) {
+			ti->error = "Error initializing journal";
+			goto bad;
+		}
+		r = sync_rw_sb(ic, REQ_OP_WRITE, REQ_FUA);
+		if (r) {
+			ti->error = "Error initializing superblock";
+			goto bad;
+		}
+		ic->just_formatted = true;
+	}
+
+	r = dm_set_target_max_io_len(ti, 1U << ic->sb->log2_interleave_sectors);
+	if (r)
+		goto bad;
+
+	if (!ic->internal_hash)
+		dm_integrity_set(ti, ic);
+
+	ti->num_flush_bios = 1;
+	ti->flush_supported = true;
+
+	return 0;
+bad:
+	dm_integrity_dtr(ti);
+	return r;
+}
+
+static void dm_integrity_dtr(struct dm_target *ti)
+{
+	struct dm_integrity_c *ic = ti->private;
+
+	BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
+
+	if (ic->metadata_wq)
+		destroy_workqueue(ic->metadata_wq);
+	if (ic->wait_wq)
+		destroy_workqueue(ic->wait_wq);
+	if (ic->commit_wq)
+		destroy_workqueue(ic->commit_wq);
+	if (ic->writer_wq)
+		destroy_workqueue(ic->writer_wq);
+	if (ic->bufio)
+		dm_bufio_client_destroy(ic->bufio);
+	mempool_destroy(ic->journal_io_mempool);
+	if (ic->io)
+		dm_io_client_destroy(ic->io);
+	if (ic->dev)
+		dm_put_device(ti, ic->dev);
+	dm_integrity_free_page_list(ic, ic->journal);
+	dm_integrity_free_page_list(ic, ic->journal_io);
+	dm_integrity_free_page_list(ic, ic->journal_xor);
+	if (ic->journal_scatterlist)
+		dm_integrity_free_journal_scatterlist(ic, ic->journal_scatterlist);
+	if (ic->journal_io_scatterlist)
+		dm_integrity_free_journal_scatterlist(ic, ic->journal_io_scatterlist);
+	if (ic->sk_requests) {
+		unsigned i;
+
+		for (i = 0; i < ic->journal_sections; i++) {
+			struct skcipher_request *req = ic->sk_requests[i];
+			if (req) {
+				kzfree(req->iv);
+				skcipher_request_free(req);
+			}
+		}
+		kvfree(ic->sk_requests);
+	}
+	kvfree(ic->journal_tree);
+	if (ic->sb)
+		free_pages_exact(ic->sb, SB_SECTORS << SECTOR_SHIFT);
+
+	if (ic->internal_hash)
+		crypto_free_shash(ic->internal_hash);
+	free_alg(&ic->internal_hash_alg);
+
+	if (ic->journal_crypt)
+		crypto_free_skcipher(ic->journal_crypt);
+	free_alg(&ic->journal_crypt_alg);
+
+	if (ic->journal_mac)
+		crypto_free_shash(ic->journal_mac);
+	free_alg(&ic->journal_mac_alg);
+
+	kfree(ic);
+}
+
+static struct target_type integrity_target = {
+	.name			= "integrity",
+	.version		= {1, 0, 0},
+	.module			= THIS_MODULE,
+	.features		= DM_TARGET_SINGLETON | DM_TARGET_INTEGRITY,
+	.ctr			= dm_integrity_ctr,
+	.dtr			= dm_integrity_dtr,
+	.map			= dm_integrity_map,
+	.postsuspend		= dm_integrity_postsuspend,
+	.resume			= dm_integrity_resume,
+	.status			= dm_integrity_status,
+	.iterate_devices	= dm_integrity_iterate_devices,
+	.io_hints		= dm_integrity_io_hints,
+};
+
+int __init dm_integrity_init(void)
+{
+	int r;
+
+	journal_io_cache = kmem_cache_create("integrity_journal_io",
+					     sizeof(struct journal_io), 0, 0, NULL);
+	if (!journal_io_cache) {
+		DMERR("can't allocate journal io cache");
+		return -ENOMEM;
+	}
+
+	r = dm_register_target(&integrity_target);
+
+	if (r < 0)
+		DMERR("register failed %d", r);
+
+	return r;
+}
+
+void dm_integrity_exit(void)
+{
+	dm_unregister_target(&integrity_target);
+	kmem_cache_destroy(journal_io_cache);
+}
+
+module_init(dm_integrity_init);
+module_exit(dm_integrity_exit);
+
+MODULE_AUTHOR("Milan Broz");
+MODULE_AUTHOR("Mikulas Patocka");
+MODULE_DESCRIPTION(DM_NAME " target for integrity tags extension");
+MODULE_LICENSE("GPL");
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 4da6fc6b1ffd..2d5d7064acbf 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -37,14 +37,6 @@ struct hash_cell {
 	struct dm_table *new_map;
 };
 
-/*
- * A dummy definition to make RCU happy.
- * struct dm_table should never be dereferenced in this file.
- */
-struct dm_table {
-	int undefined__;
-};
-
 struct vers_iter {
     size_t param_size;
     struct dm_target_versions *vers, *old_vers;
@@ -1268,7 +1260,7 @@ static int populate_table(struct dm_table *table,
 	return dm_table_complete(table);
 }
 
-static bool is_valid_type(unsigned cur, unsigned new)
+static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
 {
 	if (cur == new ||
 	    (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
@@ -1778,12 +1770,12 @@ static int validate_params(uint cmd, struct dm_ioctl *param)
 	    cmd == DM_LIST_VERSIONS_CMD)
 		return 0;
 
-	if ((cmd == DM_DEV_CREATE_CMD)) {
+	if (cmd == DM_DEV_CREATE_CMD) {
 		if (!*param->name) {
 			DMWARN("name not supplied when creating device");
 			return -EINVAL;
 		}
-	} else if ((*param->uuid && *param->name)) {
+	} else if (*param->uuid && *param->name) {
 		DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
 		return -EINVAL;
 	}
@@ -1848,7 +1840,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 	if (r)
 		goto out;
 
-	param->data_size = sizeof(*param);
+	param->data_size = offsetof(struct dm_ioctl, data);
 	r = fn(param, input_param_size);
 
 	if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index e17fd44ceef5..a5120961632a 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -163,6 +163,7 @@ static long linear_direct_access(struct dm_target *ti, sector_t sector,
 static struct target_type linear_target = {
 	.name   = "linear",
 	.version = {1, 3, 0},
+	.features = DM_TARGET_PASSES_INTEGRITY,
 	.module = THIS_MODULE,
 	.ctr    = linear_ctr,
 	.dtr    = linear_dtr,
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 2950b145443d..52cd3f1608b3 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -90,7 +90,7 @@ struct multipath {
 	atomic_t pg_init_in_progress;	/* Only one pg_init allowed at once */
 	atomic_t pg_init_count;		/* Number of times pg_init called */
 
-	unsigned queue_mode;
+	enum dm_queue_mode queue_mode;
 
 	struct mutex work_mutex;
 	struct work_struct trigger_event;
@@ -111,7 +111,8 @@ typedef int (*action_fn) (struct pgpath *pgpath);
 
 static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
 static void trigger_event(struct work_struct *work);
-static void activate_path(struct work_struct *work);
+static void activate_or_offline_path(struct pgpath *pgpath);
+static void activate_path_work(struct work_struct *work);
 static void process_queued_bios(struct work_struct *work);
 
 /*-----------------------------------------------
@@ -136,7 +137,7 @@ static struct pgpath *alloc_pgpath(void)
 
 	if (pgpath) {
 		pgpath->is_active = true;
-		INIT_DELAYED_WORK(&pgpath->activate_path, activate_path);
+		INIT_DELAYED_WORK(&pgpath->activate_path, activate_path_work);
 	}
 
 	return pgpath;
@@ -297,6 +298,8 @@ static int __pg_init_all_paths(struct multipath *m)
 	struct pgpath *pgpath;
 	unsigned long pg_init_delay = 0;
 
+	lockdep_assert_held(&m->lock);
+
 	if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
 		return 0;
 
@@ -321,13 +324,16 @@ static int __pg_init_all_paths(struct multipath *m)
 	return atomic_read(&m->pg_init_in_progress);
 }
 
-static void pg_init_all_paths(struct multipath *m)
+static int pg_init_all_paths(struct multipath *m)
 {
+	int ret;
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-	__pg_init_all_paths(m);
+	ret = __pg_init_all_paths(m);
 	spin_unlock_irqrestore(&m->lock, flags);
+
+	return ret;
 }
 
 static void __switch_pg(struct multipath *m, struct priority_group *pg)
@@ -436,45 +442,21 @@ failed:
 }
 
 /*
- * Check whether bios must be queued in the device-mapper core rather
- * than here in the target.
- *
- * If m->queue_if_no_path and m->saved_queue_if_no_path hold the
- * same value then we are not between multipath_presuspend()
- * and multipath_resume() calls and we have no need to check
- * for the DMF_NOFLUSH_SUSPENDING flag.
+ * dm_report_EIO() is a macro instead of a function to make pr_debug()
+ * report the function name and line number of the function from which
+ * it has been invoked.
  */
-static bool __must_push_back(struct multipath *m)
-{
-	return ((test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) !=
-		 test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) &&
-		dm_noflush_suspending(m->ti));
-}
-
-static bool must_push_back_rq(struct multipath *m)
-{
-	bool r;
-	unsigned long flags;
-
-	spin_lock_irqsave(&m->lock, flags);
-	r = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) ||
-	     __must_push_back(m));
-	spin_unlock_irqrestore(&m->lock, flags);
-
-	return r;
-}
-
-static bool must_push_back_bio(struct multipath *m)
-{
-	bool r;
-	unsigned long flags;
-
-	spin_lock_irqsave(&m->lock, flags);
-	r = __must_push_back(m);
-	spin_unlock_irqrestore(&m->lock, flags);
-
-	return r;
-}
+#define dm_report_EIO(m)						\
+({									\
+	struct mapped_device *md = dm_table_get_md((m)->ti->table);	\
+									\
+	pr_debug("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d\n", \
+		 dm_device_name(md),					\
+		 test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags),	\
+		 test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags),	\
+		 dm_noflush_suspending((m)->ti));			\
+	-EIO;								\
+})
 
 /*
  * Map cloned requests (request-based multipath)
@@ -484,11 +466,11 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 				   struct request **__clone)
 {
 	struct multipath *m = ti->private;
-	int r = DM_MAPIO_REQUEUE;
 	size_t nr_bytes = blk_rq_bytes(rq);
 	struct pgpath *pgpath;
 	struct block_device *bdev;
 	struct dm_mpath_io *mpio = get_mpio(map_context);
+	struct request_queue *q;
 	struct request *clone;
 
 	/* Do we need to select a new pgpath? */
@@ -497,13 +479,14 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 		pgpath = choose_pgpath(m, nr_bytes);
 
 	if (!pgpath) {
-		if (must_push_back_rq(m))
+		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
 			return DM_MAPIO_DELAY_REQUEUE;
-		return -EIO;	/* Failed */
+		return dm_report_EIO(m);	/* Failed */
 	} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
 		   test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
-		pg_init_all_paths(m);
-		return r;
+		if (pg_init_all_paths(m))
+			return DM_MAPIO_DELAY_REQUEUE;
+		return DM_MAPIO_REQUEUE;
 	}
 
 	memset(mpio, 0, sizeof(*mpio));
@@ -511,13 +494,19 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 	mpio->nr_bytes = nr_bytes;
 
 	bdev = pgpath->path.dev->bdev;
-
-	clone = blk_get_request(bdev_get_queue(bdev),
-			rq->cmd_flags | REQ_NOMERGE,
-			GFP_ATOMIC);
+	q = bdev_get_queue(bdev);
+	clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, GFP_ATOMIC);
 	if (IS_ERR(clone)) {
 		/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
-		return r;
+		bool queue_dying = blk_queue_dying(q);
+		DMERR_LIMIT("blk_get_request() returned %ld%s - requeuing",
+			    PTR_ERR(clone), queue_dying ? " (path offline)" : "");
+		if (queue_dying) {
+			atomic_inc(&m->pg_init_in_progress);
+			activate_or_offline_path(pgpath);
+			return DM_MAPIO_REQUEUE;
+		}
+		return DM_MAPIO_DELAY_REQUEUE;
 	}
 	clone->bio = clone->biotail = NULL;
 	clone->rq_disk = bdev->bd_disk;
@@ -567,9 +556,9 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
 	}
 
 	if (!pgpath) {
-		if (!must_push_back_bio(m))
-			return -EIO;
-		return DM_MAPIO_REQUEUE;
+		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+			return DM_MAPIO_REQUEUE;
+		return dm_report_EIO(m);
 	}
 
 	mpio->pgpath = pgpath;
@@ -640,6 +629,14 @@ static void process_queued_bios(struct work_struct *work)
 	blk_finish_plug(&plug);
 }
 
+static void assign_bit(bool value, long nr, unsigned long *addr)
+{
+	if (value)
+		set_bit(nr, addr);
+	else
+		clear_bit(nr, addr);
+}
+
 /*
  * If we run out of usable paths, should we queue I/O or error it?
  */
@@ -649,23 +646,11 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-
-	if (save_old_value) {
-		if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
-			set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-		else
-			clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-	} else {
-		if (queue_if_no_path)
-			set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-		else
-			clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
-	}
-	if (queue_if_no_path)
-		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-	else
-		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-
+	assign_bit((save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) ||
+		   (!save_old_value && queue_if_no_path),
+		   MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(queue_if_no_path || dm_noflush_suspending(m->ti),
+		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
 	spin_unlock_irqrestore(&m->lock, flags);
 
 	if (!queue_if_no_path) {
@@ -1438,10 +1423,8 @@ out:
 	spin_unlock_irqrestore(&m->lock, flags);
 }
 
-static void activate_path(struct work_struct *work)
+static void activate_or_offline_path(struct pgpath *pgpath)
 {
-	struct pgpath *pgpath =
-		container_of(work, struct pgpath, activate_path.work);
 	struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
 
 	if (pgpath->is_active && !blk_queue_dying(q))
@@ -1450,6 +1433,14 @@ static void activate_path(struct work_struct *work)
 		pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
 }
 
+static void activate_path_work(struct work_struct *work)
+{
+	struct pgpath *pgpath =
+		container_of(work, struct pgpath, activate_path.work);
+
+	activate_or_offline_path(pgpath);
+}
+
 static int noretry_error(int error)
 {
 	switch (error) {
@@ -1501,12 +1492,9 @@ static int do_end_io(struct multipath *m, struct request *clone,
 	if (mpio->pgpath)
 		fail_path(mpio->pgpath);
 
-	if (!atomic_read(&m->nr_valid_paths)) {
-		if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
-			if (!must_push_back_rq(m))
-				r = -EIO;
-		}
-	}
+	if (atomic_read(&m->nr_valid_paths) == 0 &&
+	    !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+		r = dm_report_EIO(m);
 
 	return r;
 }
@@ -1547,13 +1535,9 @@ static int do_end_io_bio(struct multipath *m, struct bio *clone,
 	if (mpio->pgpath)
 		fail_path(mpio->pgpath);
 
-	if (!atomic_read(&m->nr_valid_paths)) {
-		if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
-			if (!must_push_back_bio(m))
-				return -EIO;
-			return DM_ENDIO_REQUEUE;
-		}
-	}
+	if (atomic_read(&m->nr_valid_paths) == 0 &&
+	    !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
+		return dm_report_EIO(m);
 
 	/* Queue for the daemon to resubmit */
 	dm_bio_restore(get_bio_details_from_bio(clone), clone);
@@ -1619,10 +1603,8 @@ static void multipath_resume(struct dm_target *ti)
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
-	if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))
-		set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
-	else
-		clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
+	assign_bit(test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags),
+		   MPATHF_QUEUE_IF_NO_PATH, &m->flags);
 	spin_unlock_irqrestore(&m->lock, flags);
 }
 
@@ -1682,6 +1664,9 @@ static void multipath_status(struct dm_target *ti, status_type_t type,
 			case DM_TYPE_MQ_REQUEST_BASED:
 				DMEMIT("queue_mode mq ");
 				break;
+			default:
+				WARN_ON_ONCE(true);
+				break;
 			}
 		}
 	}
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 2dae3e5b851c..7d893228c40f 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2010-2011 Neil Brown
- * Copyright (C) 2010-2016 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2010-2017 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
@@ -79,7 +79,10 @@ struct raid_dev {
 #define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
 
 /* New for v1.10.0 */
-#define __CTR_FLAG_JOURNAL_DEV		15 /* 2 */ /* Only with raid4/5/6! */
+#define __CTR_FLAG_JOURNAL_DEV		15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
+
+/* New for v1.11.1 */
+#define __CTR_FLAG_JOURNAL_MODE		16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
 
 /*
  * Flags for rs->ctr_flags field.
@@ -100,6 +103,7 @@ struct raid_dev {
 #define CTR_FLAG_DATA_OFFSET		(1 << __CTR_FLAG_DATA_OFFSET)
 #define CTR_FLAG_RAID10_USE_NEAR_SETS	(1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
 #define CTR_FLAG_JOURNAL_DEV		(1 << __CTR_FLAG_JOURNAL_DEV)
+#define CTR_FLAG_JOURNAL_MODE		(1 << __CTR_FLAG_JOURNAL_MODE)
 
 #define RESUME_STAY_FROZEN_FLAGS (CTR_FLAG_DELTA_DISKS | CTR_FLAG_DATA_OFFSET)
 
@@ -175,7 +179,8 @@ struct raid_dev {
 				 CTR_FLAG_REGION_SIZE | \
 				 CTR_FLAG_DELTA_DISKS | \
 				 CTR_FLAG_DATA_OFFSET | \
-				 CTR_FLAG_JOURNAL_DEV)
+				 CTR_FLAG_JOURNAL_DEV | \
+				 CTR_FLAG_JOURNAL_MODE)
 
 #define RAID6_VALID_FLAGS	(CTR_FLAG_SYNC | \
 				 CTR_FLAG_REBUILD | \
@@ -186,7 +191,8 @@ struct raid_dev {
 				 CTR_FLAG_REGION_SIZE | \
 				 CTR_FLAG_DELTA_DISKS | \
 				 CTR_FLAG_DATA_OFFSET | \
-				 CTR_FLAG_JOURNAL_DEV)
+				 CTR_FLAG_JOURNAL_DEV | \
+				 CTR_FLAG_JOURNAL_MODE)
 /* ...valid options definitions per raid level */
 
 /*
@@ -239,6 +245,7 @@ struct raid_set {
 	struct journal_dev {
 		struct dm_dev *dev;
 		struct md_rdev rdev;
+		int mode;
 	} journal_dev;
 
 	struct raid_dev dev[0];
@@ -326,6 +333,7 @@ static struct arg_name_flag {
 	{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
 	{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 	{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
+	{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
 };
 
 /* Return argument name string for given @flag */
@@ -344,6 +352,39 @@ static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 	return NULL;
 }
 
+/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
+static struct {
+	const int mode;
+	const char *param;
+} _raid456_journal_mode[] = {
+	{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
+	{ R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
+};
+
+/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
+static int dm_raid_journal_mode_to_md(const char *mode)
+{
+	int m = ARRAY_SIZE(_raid456_journal_mode);
+
+	while (m--)
+		if (!strcasecmp(mode, _raid456_journal_mode[m].param))
+			return _raid456_journal_mode[m].mode;
+
+	return -EINVAL;
+}
+
+/* Return dm-raid raid4/5/6 journal mode string for @mode */
+static const char *md_journal_mode_to_dm_raid(const int mode)
+{
+	int m = ARRAY_SIZE(_raid456_journal_mode);
+
+	while (m--)
+		if (mode == _raid456_journal_mode[m].mode)
+			return _raid456_journal_mode[m].param;
+
+	return "unknown";
+}
+
 /*
  * Bool helpers to test for various raid levels of a raid set.
  * It's level as reported by the superblock rather than
@@ -1183,7 +1224,7 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
 			continue;
 		}
 
-		/* "journal_dev dev" */
+		/* "journal_dev <dev>" */
 		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
 			int r;
 			struct md_rdev *jdev;
@@ -1211,10 +1252,32 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
 				rs->ti->error = "No space for raid4/5/6 journal";
 				return -ENOSPC;
 			}
+			rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
 			set_bit(Journal, &jdev->flags);
 			continue;
 		}
 
+		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
+		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
+			int r;
+
+			if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
+				rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
+				return -EINVAL;
+			}
+			if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
+				rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
+				return -EINVAL;
+			}
+			r = dm_raid_journal_mode_to_md(arg);
+			if (r < 0) {
+				rs->ti->error = "Invalid 'journal_mode' argument";
+				return r;
+			}
+			rs->journal_dev.mode = r;
+			continue;
+		}
+
 		/*
 		 * Parameters with number values from here on.
 		 */
@@ -3076,6 +3139,16 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	rs->callbacks.congested_fn = raid_is_congested;
 	dm_table_add_target_callbacks(ti->table, &rs->callbacks);
 
+	/* If raid4/5/6 journal mode explictely requested (only possible with journal dev) -> set it */
+	if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
+		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
+		if (r) {
+			ti->error = "Failed to set raid4/5/6 journal mode";
+			mddev_unlock(&rs->md);
+			goto bad_journal_mode_set;
+		}
+	}
+
 	mddev_suspend(&rs->md);
 
 	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
@@ -3109,6 +3182,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	mddev_unlock(&rs->md);
 	return 0;
 
+bad_journal_mode_set:
 bad_stripe_cache:
 bad_check_reshape:
 	md_stop(&rs->md);
@@ -3180,18 +3254,18 @@ static const char *decipher_sync_action(struct mddev *mddev)
  * Status characters:
  *
  *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
- *  'a' = Alive but not in-sync
- *  'A' = Alive and in-sync raid set component or alive raid4/5/6 journal device
+ *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
+ *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
  *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
  */
-static const char *__raid_dev_status(struct md_rdev *rdev, bool array_in_sync)
+static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev, bool array_in_sync)
 {
 	if (!rdev->bdev)
 		return "-";
 	else if (test_bit(Faulty, &rdev->flags))
 		return "D";
 	else if (test_bit(Journal, &rdev->flags))
-		return "A";
+		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
 	else if (!array_in_sync || !test_bit(In_sync, &rdev->flags))
 		return "a";
 	else
@@ -3315,7 +3389,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 
 		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
 		for (i = 0; i < rs->raid_disks; i++)
-			DMEMIT(__raid_dev_status(&rs->dev[i].rdev, array_in_sync));
+			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev, array_in_sync));
 
 		/*
 		 * In-sync/Reshape ratio:
@@ -3366,7 +3440,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 		 * v1.10.0+:
 		 */
 		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
-			      __raid_dev_status(&rs->journal_dev.rdev, 0) : "-");
+			      __raid_dev_status(rs, &rs->journal_dev.rdev, 0) : "-");
 		break;
 
 	case STATUSTYPE_TABLE:
@@ -3381,39 +3455,30 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 				  write_mostly_params +
 				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
 				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2 +
-				  (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0);
+				  (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0) +
+				  (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags) ? 2 : 0);
+
 		/* Emit table line */
+		/* This has to be in the documented order for userspace! */
 		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
-		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
-			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
-					 raid10_md_layout_to_format(mddev->layout));
-		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
-			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
-					 raid10_md_layout_to_copies(mddev->layout));
-		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
-			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
 		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
 			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
-		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
-			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
-					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
-		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
-			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
-					   (unsigned long long) rs->data_offset);
-		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
-			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
-					  mddev->bitmap_info.daemon_sleep);
-		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
-			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
-					 max(rs->delta_disks, mddev->delta_disks));
-		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
-			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
-					 max_nr_stripes);
+		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
+			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
 		if (rebuild_disks)
 			for (i = 0; i < rs->raid_disks; i++)
 				if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
 					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
 							 rs->dev[i].rdev.raid_disk);
+		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
+			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
+					  mddev->bitmap_info.daemon_sleep);
+		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
+			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
+					 mddev->sync_speed_min);
+		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
+			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
+					 mddev->sync_speed_max);
 		if (write_mostly_params)
 			for (i = 0; i < rs->raid_disks; i++)
 				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
@@ -3422,15 +3487,30 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
 			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
 					  mddev->bitmap_info.max_write_behind);
-		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
-			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
-					 mddev->sync_speed_max);
-		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
-			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
-					 mddev->sync_speed_min);
+		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
+			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
+					 max_nr_stripes);
+		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
+			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
+					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
+		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
+			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
+					 raid10_md_layout_to_copies(mddev->layout));
+		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
+			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
+					 raid10_md_layout_to_format(mddev->layout));
+		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
+			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
+					 max(rs->delta_disks, mddev->delta_disks));
+		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
+			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
+					   (unsigned long long) rs->data_offset);
 		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
 			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
 					__get_dev_name(rs->journal_dev.dev));
+		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
+			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
+					 md_journal_mode_to_dm_raid(rs->journal_dev.mode));
 		DMEMIT(" %d", rs->raid_disks);
 		for (i = 0; i < rs->raid_disks; i++)
 			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
@@ -3791,7 +3871,7 @@ static void raid_resume(struct dm_target *ti)
 
 static struct target_type raid_target = {
 	.name = "raid",
-	.version = {1, 10, 1},
+	.version = {1, 11, 1},
 	.module = THIS_MODULE,
 	.ctr = raid_ctr,
 	.dtr = raid_dtr,
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index bff7e3bdb4ed..d445b712970b 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -280,7 +280,7 @@ static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_
 	if (!rq->q->mq_ops)
 		dm_old_requeue_request(rq);
 	else
-		dm_mq_delay_requeue_request(rq, delay_requeue ? 5000 : 0);
+		dm_mq_delay_requeue_request(rq, delay_requeue ? 100/*ms*/ : 0);
 
 	rq_completed(md, rw, false);
 }
@@ -815,10 +815,14 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t)
 	dm_init_md_queue(md);
 
 	/* backfill 'mq' sysfs registration normally done in blk_register_queue */
-	blk_mq_register_dev(disk_to_dev(md->disk), q);
+	err = blk_mq_register_dev(disk_to_dev(md->disk), q);
+	if (err)
+		goto out_cleanup_queue;
 
 	return 0;
 
+out_cleanup_queue:
+	blk_cleanup_queue(q);
 out_tag_set:
 	blk_mq_free_tag_set(md->tag_set);
 out_kfree_tag_set:
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 5ef49c121d99..4b50ae115c6d 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -442,6 +442,7 @@ static void stripe_io_hints(struct dm_target *ti,
 static struct target_type stripe_target = {
 	.name   = "striped",
 	.version = {1, 6, 0},
+	.features = DM_TARGET_PASSES_INTEGRITY,
 	.module = THIS_MODULE,
 	.ctr    = stripe_ctr,
 	.dtr    = stripe_dtr,
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 958275aca008..5f5eae41f804 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -30,7 +30,7 @@
 
 struct dm_table {
 	struct mapped_device *md;
-	unsigned type;
+	enum dm_queue_mode type;
 
 	/* btree table */
 	unsigned int depth;
@@ -47,6 +47,7 @@ struct dm_table {
 	bool integrity_supported:1;
 	bool singleton:1;
 	bool all_blk_mq:1;
+	unsigned integrity_added:1;
 
 	/*
 	 * Indicates the rw permissions for the new logical
@@ -372,7 +373,7 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
  */
 dev_t dm_get_dev_t(const char *path)
 {
-	dev_t uninitialized_var(dev);
+	dev_t dev;
 	struct block_device *bdev;
 
 	bdev = lookup_bdev(path);
@@ -626,13 +627,13 @@ static int validate_hardware_logical_block_alignment(struct dm_table *table,
 
 	struct dm_target *uninitialized_var(ti);
 	struct queue_limits ti_limits;
-	unsigned i = 0;
+	unsigned i;
 
 	/*
 	 * Check each entry in the table in turn.
 	 */
-	while (i < dm_table_get_num_targets(table)) {
-		ti = dm_table_get_target(table, i++);
+	for (i = 0; i < dm_table_get_num_targets(table); i++) {
+		ti = dm_table_get_target(table, i);
 
 		blk_set_stacking_limits(&ti_limits);
 
@@ -725,6 +726,9 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 		t->immutable_target_type = tgt->type;
 	}
 
+	if (dm_target_has_integrity(tgt->type))
+		t->integrity_added = 1;
+
 	tgt->table = t;
 	tgt->begin = start;
 	tgt->len = len;
@@ -821,19 +825,19 @@ void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 }
 EXPORT_SYMBOL(dm_consume_args);
 
-static bool __table_type_bio_based(unsigned table_type)
+static bool __table_type_bio_based(enum dm_queue_mode table_type)
 {
 	return (table_type == DM_TYPE_BIO_BASED ||
 		table_type == DM_TYPE_DAX_BIO_BASED);
 }
 
-static bool __table_type_request_based(unsigned table_type)
+static bool __table_type_request_based(enum dm_queue_mode table_type)
 {
 	return (table_type == DM_TYPE_REQUEST_BASED ||
 		table_type == DM_TYPE_MQ_REQUEST_BASED);
 }
 
-void dm_table_set_type(struct dm_table *t, unsigned type)
+void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 {
 	t->type = type;
 }
@@ -850,11 +854,11 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 static bool dm_table_supports_dax(struct dm_table *t)
 {
 	struct dm_target *ti;
-	unsigned i = 0;
+	unsigned i;
 
 	/* Ensure that all targets support DAX. */
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 
 		if (!ti->type->direct_access)
 			return false;
@@ -875,7 +879,7 @@ static int dm_table_determine_type(struct dm_table *t)
 	struct dm_target *tgt;
 	struct dm_dev_internal *dd;
 	struct list_head *devices = dm_table_get_devices(t);
-	unsigned live_md_type = dm_get_md_type(t->md);
+	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 
 	if (t->type != DM_TYPE_NONE) {
 		/* target already set the table's type */
@@ -984,7 +988,7 @@ verify_rq_based:
 	return 0;
 }
 
-unsigned dm_table_get_type(struct dm_table *t)
+enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 {
 	return t->type;
 }
@@ -1006,11 +1010,11 @@ struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 
 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
 {
-	struct dm_target *uninitialized_var(ti);
-	unsigned i = 0;
+	struct dm_target *ti;
+	unsigned i;
 
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 		if (dm_target_is_wildcard(ti->type))
 			return ti;
 	}
@@ -1035,7 +1039,7 @@ bool dm_table_all_blk_mq_devices(struct dm_table *t)
 
 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
 {
-	unsigned type = dm_table_get_type(t);
+	enum dm_queue_mode type = dm_table_get_type(t);
 	unsigned per_io_data_size = 0;
 	struct dm_target *tgt;
 	unsigned i;
@@ -1131,6 +1135,13 @@ static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
 	struct list_head *devices = dm_table_get_devices(t);
 	struct dm_dev_internal *dd = NULL;
 	struct gendisk *prev_disk = NULL, *template_disk = NULL;
+	unsigned i;
+
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		struct dm_target *ti = dm_table_get_target(t, i);
+		if (!dm_target_passes_integrity(ti->type))
+			goto no_integrity;
+	}
 
 	list_for_each_entry(dd, devices, list) {
 		template_disk = dd->dm_dev->bdev->bd_disk;
@@ -1168,6 +1179,10 @@ static int dm_table_register_integrity(struct dm_table *t)
 	struct mapped_device *md = t->md;
 	struct gendisk *template_disk = NULL;
 
+	/* If target handles integrity itself do not register it here. */
+	if (t->integrity_added)
+		return 0;
+
 	template_disk = dm_table_get_integrity_disk(t);
 	if (!template_disk)
 		return 0;
@@ -1313,15 +1328,16 @@ static int count_device(struct dm_target *ti, struct dm_dev *dev,
  */
 bool dm_table_has_no_data_devices(struct dm_table *table)
 {
-	struct dm_target *uninitialized_var(ti);
-	unsigned i = 0, num_devices = 0;
+	struct dm_target *ti;
+	unsigned i, num_devices;
 
-	while (i < dm_table_get_num_targets(table)) {
-		ti = dm_table_get_target(table, i++);
+	for (i = 0; i < dm_table_get_num_targets(table); i++) {
+		ti = dm_table_get_target(table, i);
 
 		if (!ti->type->iterate_devices)
 			return false;
 
+		num_devices = 0;
 		ti->type->iterate_devices(ti, count_device, &num_devices);
 		if (num_devices)
 			return false;
@@ -1336,16 +1352,16 @@ bool dm_table_has_no_data_devices(struct dm_table *table)
 int dm_calculate_queue_limits(struct dm_table *table,
 			      struct queue_limits *limits)
 {
-	struct dm_target *uninitialized_var(ti);
+	struct dm_target *ti;
 	struct queue_limits ti_limits;
-	unsigned i = 0;
+	unsigned i;
 
 	blk_set_stacking_limits(limits);
 
-	while (i < dm_table_get_num_targets(table)) {
+	for (i = 0; i < dm_table_get_num_targets(table); i++) {
 		blk_set_stacking_limits(&ti_limits);
 
-		ti = dm_table_get_target(table, i++);
+		ti = dm_table_get_target(table, i);
 
 		if (!ti->type->iterate_devices)
 			goto combine_limits;
@@ -1394,6 +1410,9 @@ static void dm_table_verify_integrity(struct dm_table *t)
 {
 	struct gendisk *template_disk = NULL;
 
+	if (t->integrity_added)
+		return;
+
 	if (t->integrity_supported) {
 		/*
 		 * Verify that the original integrity profile
@@ -1424,7 +1443,7 @@ static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
 {
 	struct dm_target *ti;
-	unsigned i = 0;
+	unsigned i;
 
 	/*
 	 * Require at least one underlying device to support flushes.
@@ -1432,8 +1451,8 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
 	 * so we need to use iterate_devices here, which targets
 	 * supporting flushes must provide.
 	 */
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 
 		if (!ti->num_flush_bios)
 			continue;
@@ -1477,10 +1496,10 @@ static bool dm_table_all_devices_attribute(struct dm_table *t,
 					   iterate_devices_callout_fn func)
 {
 	struct dm_target *ti;
-	unsigned i = 0;
+	unsigned i;
 
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 
 		if (!ti->type->iterate_devices ||
 		    !ti->type->iterate_devices(ti, func, NULL))
@@ -1501,10 +1520,10 @@ static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *de
 static bool dm_table_supports_write_same(struct dm_table *t)
 {
 	struct dm_target *ti;
-	unsigned i = 0;
+	unsigned i;
 
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 
 		if (!ti->num_write_same_bios)
 			return false;
@@ -1556,7 +1575,7 @@ static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
 static bool dm_table_supports_discards(struct dm_table *t)
 {
 	struct dm_target *ti;
-	unsigned i = 0;
+	unsigned i;
 
 	/*
 	 * Unless any target used by the table set discards_supported,
@@ -1565,8 +1584,8 @@ static bool dm_table_supports_discards(struct dm_table *t)
 	 * so we need to use iterate_devices here, which targets
 	 * supporting discard selectively must provide.
 	 */
-	while (i < dm_table_get_num_targets(t)) {
-		ti = dm_table_get_target(t, i++);
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
 
 		if (!ti->num_discard_bios)
 			continue;
@@ -1672,6 +1691,8 @@ static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
 	int i = t->num_targets;
 	struct dm_target *ti = t->targets;
 
+	lockdep_assert_held(&t->md->suspend_lock);
+
 	while (i--) {
 		switch (mode) {
 		case PRESUSPEND:
@@ -1719,6 +1740,8 @@ int dm_table_resume_targets(struct dm_table *t)
 {
 	int i, r = 0;
 
+	lockdep_assert_held(&t->md->suspend_lock);
+
 	for (i = 0; i < t->num_targets; i++) {
 		struct dm_target *ti = t->targets + i;
 
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index a15091a0d40c..0f0251d0d337 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -77,7 +77,6 @@
 #define THIN_SUPERBLOCK_MAGIC 27022010
 #define THIN_SUPERBLOCK_LOCATION 0
 #define THIN_VERSION 2
-#define THIN_METADATA_CACHE_SIZE 64
 #define SECTOR_TO_BLOCK_SHIFT 3
 
 /*
@@ -686,7 +685,6 @@ static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool f
 	int r;
 
 	pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
-					  THIN_METADATA_CACHE_SIZE,
 					  THIN_MAX_CONCURRENT_LOCKS);
 	if (IS_ERR(pmd->bm)) {
 		DMERR("could not create block manager");
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index a5f1916f621a..17ad50daed08 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -5,7 +5,7 @@
  */
 
 #include "dm-thin-metadata.h"
-#include "dm-bio-prison.h"
+#include "dm-bio-prison-v1.h"
 #include "dm.h"
 
 #include <linux/device-mapper.h>
@@ -1069,6 +1069,7 @@ static void passdown_endio(struct bio *bio)
 	 * to unmap (we ignore err).
 	 */
 	queue_passdown_pt2(bio->bi_private);
+	bio_put(bio);
 }
 
 static void process_prepared_discard_passdown_pt1(struct dm_thin_new_mapping *m)
diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index 78f36012eaca..504ba3fa328b 100644
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -188,7 +188,7 @@ error:
 static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io,
 			  u8 *want_digest, u8 *data)
 {
-	if (unlikely(verity_hash(v, verity_io_hash_desc(v, io),
+	if (unlikely(verity_hash(v, verity_io_hash_req(v, io),
 				 data, 1 << v->data_dev_block_bits,
 				 verity_io_real_digest(v, io))))
 		return 0;
@@ -397,7 +397,7 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
 	}
 
 	/* Always re-validate the corrected block against the expected hash */
-	r = verity_hash(v, verity_io_hash_desc(v, io), fio->output,
+	r = verity_hash(v, verity_io_hash_req(v, io), fio->output,
 			1 << v->data_dev_block_bits,
 			verity_io_real_digest(v, io));
 	if (unlikely(r < 0))
diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 7335d8a3fc47..97de961a3bfc 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -93,81 +93,123 @@ static sector_t verity_position_at_level(struct dm_verity *v, sector_t block,
 }
 
 /*
- * Wrapper for crypto_shash_init, which handles verity salting.
+ * Callback function for asynchrnous crypto API completion notification
  */
-static int verity_hash_init(struct dm_verity *v, struct shash_desc *desc)
+static void verity_op_done(struct crypto_async_request *base, int err)
 {
-	int r;
+	struct verity_result *res = (struct verity_result *)base->data;
 
-	desc->tfm = v->tfm;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+	if (err == -EINPROGRESS)
+		return;
 
-	r = crypto_shash_init(desc);
+	res->err = err;
+	complete(&res->completion);
+}
 
-	if (unlikely(r < 0)) {
-		DMERR("crypto_shash_init failed: %d", r);
-		return r;
-	}
+/*
+ * Wait for async crypto API callback
+ */
+static inline int verity_complete_op(struct verity_result *res, int ret)
+{
+	switch (ret) {
+	case 0:
+		break;
 
-	if (likely(v->version >= 1)) {
-		r = crypto_shash_update(desc, v->salt, v->salt_size);
+	case -EINPROGRESS:
+	case -EBUSY:
+		ret = wait_for_completion_interruptible(&res->completion);
+		if (!ret)
+			ret = res->err;
+		reinit_completion(&res->completion);
+		break;
 
-		if (unlikely(r < 0)) {
-			DMERR("crypto_shash_update failed: %d", r);
-			return r;
-		}
+	default:
+		DMERR("verity_wait_hash: crypto op submission failed: %d", ret);
 	}
 
-	return 0;
+	if (unlikely(ret < 0))
+		DMERR("verity_wait_hash: crypto op failed: %d", ret);
+
+	return ret;
 }
 
-static int verity_hash_update(struct dm_verity *v, struct shash_desc *desc,
-			      const u8 *data, size_t len)
+static int verity_hash_update(struct dm_verity *v, struct ahash_request *req,
+				const u8 *data, size_t len,
+				struct verity_result *res)
 {
-	int r = crypto_shash_update(desc, data, len);
+	struct scatterlist sg;
 
-	if (unlikely(r < 0))
-		DMERR("crypto_shash_update failed: %d", r);
+	sg_init_one(&sg, data, len);
+	ahash_request_set_crypt(req, &sg, NULL, len);
+
+	return verity_complete_op(res, crypto_ahash_update(req));
+}
+
+/*
+ * Wrapper for crypto_ahash_init, which handles verity salting.
+ */
+static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
+				struct verity_result *res)
+{
+	int r;
+
+	ahash_request_set_tfm(req, v->tfm);
+	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP |
+					CRYPTO_TFM_REQ_MAY_BACKLOG,
+					verity_op_done, (void *)res);
+	init_completion(&res->completion);
+
+	r = verity_complete_op(res, crypto_ahash_init(req));
+
+	if (unlikely(r < 0)) {
+		DMERR("crypto_ahash_init failed: %d", r);
+		return r;
+	}
+
+	if (likely(v->version >= 1))
+		r = verity_hash_update(v, req, v->salt, v->salt_size, res);
 
 	return r;
 }
 
-static int verity_hash_final(struct dm_verity *v, struct shash_desc *desc,
-			     u8 *digest)
+static int verity_hash_final(struct dm_verity *v, struct ahash_request *req,
+			     u8 *digest, struct verity_result *res)
 {
 	int r;
 
 	if (unlikely(!v->version)) {
-		r = crypto_shash_update(desc, v->salt, v->salt_size);
+		r = verity_hash_update(v, req, v->salt, v->salt_size, res);
 
 		if (r < 0) {
-			DMERR("crypto_shash_update failed: %d", r);
-			return r;
+			DMERR("verity_hash_final failed updating salt: %d", r);
+			goto out;
 		}
 	}
 
-	r = crypto_shash_final(desc, digest);
-
-	if (unlikely(r < 0))
-		DMERR("crypto_shash_final failed: %d", r);
-
+	ahash_request_set_crypt(req, NULL, digest, 0);
+	r = verity_complete_op(res, crypto_ahash_final(req));
+out:
 	return r;
 }
 
-int verity_hash(struct dm_verity *v, struct shash_desc *desc,
+int verity_hash(struct dm_verity *v, struct ahash_request *req,
 		const u8 *data, size_t len, u8 *digest)
 {
 	int r;
+	struct verity_result res;
 
-	r = verity_hash_init(v, desc);
+	r = verity_hash_init(v, req, &res);
 	if (unlikely(r < 0))
-		return r;
+		goto out;
 
-	r = verity_hash_update(v, desc, data, len);
+	r = verity_hash_update(v, req, data, len, &res);
 	if (unlikely(r < 0))
-		return r;
+		goto out;
+
+	r = verity_hash_final(v, req, digest, &res);
 
-	return verity_hash_final(v, desc, digest);
+out:
+	return r;
 }
 
 static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level,
@@ -275,7 +317,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 			goto release_ret_r;
 		}
 
-		r = verity_hash(v, verity_io_hash_desc(v, io),
+		r = verity_hash(v, verity_io_hash_req(v, io),
 				data, 1 << v->hash_dev_block_bits,
 				verity_io_real_digest(v, io));
 		if (unlikely(r < 0))
@@ -344,6 +386,49 @@ out:
 }
 
 /*
+ * Calculates the digest for the given bio
+ */
+int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io,
+			struct bvec_iter *iter, struct verity_result *res)
+{
+	unsigned int todo = 1 << v->data_dev_block_bits;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
+	struct scatterlist sg;
+	struct ahash_request *req = verity_io_hash_req(v, io);
+
+	do {
+		int r;
+		unsigned int len;
+		struct bio_vec bv = bio_iter_iovec(bio, *iter);
+
+		sg_init_table(&sg, 1);
+
+		len = bv.bv_len;
+
+		if (likely(len >= todo))
+			len = todo;
+		/*
+		 * Operating on a single page at a time looks suboptimal
+		 * until you consider the typical block size is 4,096B.
+		 * Going through this loops twice should be very rare.
+		 */
+		sg_set_page(&sg, bv.bv_page, len, bv.bv_offset);
+		ahash_request_set_crypt(req, &sg, NULL, len);
+		r = verity_complete_op(res, crypto_ahash_update(req));
+
+		if (unlikely(r < 0)) {
+			DMERR("verity_for_io_block crypto op failed: %d", r);
+			return r;
+		}
+
+		bio_advance_iter(bio, iter, len);
+		todo -= len;
+	} while (todo);
+
+	return 0;
+}
+
+/*
  * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec
  * starting from iter.
  */
@@ -381,12 +466,6 @@ int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
 	return 0;
 }
 
-static int verity_bv_hash_update(struct dm_verity *v, struct dm_verity_io *io,
-				 u8 *data, size_t len)
-{
-	return verity_hash_update(v, verity_io_hash_desc(v, io), data, len);
-}
-
 static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io,
 			  u8 *data, size_t len)
 {
@@ -403,10 +482,11 @@ static int verity_verify_io(struct dm_verity_io *io)
 	struct dm_verity *v = io->v;
 	struct bvec_iter start;
 	unsigned b;
+	struct verity_result res;
 
 	for (b = 0; b < io->n_blocks; b++) {
 		int r;
-		struct shash_desc *desc = verity_io_hash_desc(v, io);
+		struct ahash_request *req = verity_io_hash_req(v, io);
 
 		r = verity_hash_for_block(v, io, io->block + b,
 					  verity_io_want_digest(v, io),
@@ -427,16 +507,17 @@ static int verity_verify_io(struct dm_verity_io *io)
 			continue;
 		}
 
-		r = verity_hash_init(v, desc);
+		r = verity_hash_init(v, req, &res);
 		if (unlikely(r < 0))
 			return r;
 
 		start = io->iter;
-		r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update);
+		r = verity_for_io_block(v, io, &io->iter, &res);
 		if (unlikely(r < 0))
 			return r;
 
-		r = verity_hash_final(v, desc, verity_io_real_digest(v, io));
+		r = verity_hash_final(v, req, verity_io_real_digest(v, io),
+					&res);
 		if (unlikely(r < 0))
 			return r;
 
@@ -705,7 +786,7 @@ static void verity_dtr(struct dm_target *ti)
 	kfree(v->zero_digest);
 
 	if (v->tfm)
-		crypto_free_shash(v->tfm);
+		crypto_free_ahash(v->tfm);
 
 	kfree(v->alg_name);
 
@@ -723,7 +804,7 @@ static void verity_dtr(struct dm_target *ti)
 static int verity_alloc_zero_digest(struct dm_verity *v)
 {
 	int r = -ENOMEM;
-	struct shash_desc *desc;
+	struct ahash_request *req;
 	u8 *zero_data;
 
 	v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL);
@@ -731,9 +812,9 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
 	if (!v->zero_digest)
 		return r;
 
-	desc = kmalloc(v->shash_descsize, GFP_KERNEL);
+	req = kmalloc(v->ahash_reqsize, GFP_KERNEL);
 
-	if (!desc)
+	if (!req)
 		return r; /* verity_dtr will free zero_digest */
 
 	zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL);
@@ -741,11 +822,11 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
 	if (!zero_data)
 		goto out;
 
-	r = verity_hash(v, desc, zero_data, 1 << v->data_dev_block_bits,
+	r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits,
 			v->zero_digest);
 
 out:
-	kfree(desc);
+	kfree(req);
 	kfree(zero_data);
 
 	return r;
@@ -923,21 +1004,21 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 		goto bad;
 	}
 
-	v->tfm = crypto_alloc_shash(v->alg_name, 0, 0);
+	v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0);
 	if (IS_ERR(v->tfm)) {
 		ti->error = "Cannot initialize hash function";
 		r = PTR_ERR(v->tfm);
 		v->tfm = NULL;
 		goto bad;
 	}
-	v->digest_size = crypto_shash_digestsize(v->tfm);
+	v->digest_size = crypto_ahash_digestsize(v->tfm);
 	if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) {
 		ti->error = "Digest size too big";
 		r = -EINVAL;
 		goto bad;
 	}
-	v->shash_descsize =
-		sizeof(struct shash_desc) + crypto_shash_descsize(v->tfm);
+	v->ahash_reqsize = sizeof(struct ahash_request) +
+		crypto_ahash_reqsize(v->tfm);
 
 	v->root_digest = kmalloc(v->digest_size, GFP_KERNEL);
 	if (!v->root_digest) {
@@ -1037,7 +1118,7 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	}
 
 	ti->per_io_data_size = sizeof(struct dm_verity_io) +
-				v->shash_descsize + v->digest_size * 2;
+				v->ahash_reqsize + v->digest_size * 2;
 
 	r = verity_fec_ctr(v);
 	if (r)
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index fb419f422d73..a59e0ada6fd3 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -37,7 +37,7 @@ struct dm_verity {
 	struct dm_target *ti;
 	struct dm_bufio_client *bufio;
 	char *alg_name;
-	struct crypto_shash *tfm;
+	struct crypto_ahash *tfm;
 	u8 *root_digest;	/* digest of the root block */
 	u8 *salt;		/* salt: its size is salt_size */
 	u8 *zero_digest;	/* digest for a zero block */
@@ -52,7 +52,7 @@ struct dm_verity {
 	unsigned char levels;	/* the number of tree levels */
 	unsigned char version;
 	unsigned digest_size;	/* digest size for the current hash algorithm */
-	unsigned shash_descsize;/* the size of temporary space for crypto */
+	unsigned int ahash_reqsize;/* the size of temporary space for crypto */
 	int hash_failed;	/* set to 1 if hash of any block failed */
 	enum verity_mode mode;	/* mode for handling verification errors */
 	unsigned corrupted_errs;/* Number of errors for corrupted blocks */
@@ -81,31 +81,36 @@ struct dm_verity_io {
 	/*
 	 * Three variably-size fields follow this struct:
 	 *
-	 * u8 hash_desc[v->shash_descsize];
+	 * u8 hash_req[v->ahash_reqsize];
 	 * u8 real_digest[v->digest_size];
 	 * u8 want_digest[v->digest_size];
 	 *
-	 * To access them use: verity_io_hash_desc(), verity_io_real_digest()
+	 * To access them use: verity_io_hash_req(), verity_io_real_digest()
 	 * and verity_io_want_digest().
 	 */
 };
 
-static inline struct shash_desc *verity_io_hash_desc(struct dm_verity *v,
+struct verity_result {
+	struct completion completion;
+	int err;
+};
+
+static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v,
 						     struct dm_verity_io *io)
 {
-	return (struct shash_desc *)(io + 1);
+	return (struct ahash_request *)(io + 1);
 }
 
 static inline u8 *verity_io_real_digest(struct dm_verity *v,
 					struct dm_verity_io *io)
 {
-	return (u8 *)(io + 1) + v->shash_descsize;
+	return (u8 *)(io + 1) + v->ahash_reqsize;
 }
 
 static inline u8 *verity_io_want_digest(struct dm_verity *v,
 					struct dm_verity_io *io)
 {
-	return (u8 *)(io + 1) + v->shash_descsize + v->digest_size;
+	return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size;
 }
 
 static inline u8 *verity_io_digest_end(struct dm_verity *v,
@@ -120,7 +125,7 @@ extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
 					      struct dm_verity_io *io,
 					      u8 *data, size_t len));
 
-extern int verity_hash(struct dm_verity *v, struct shash_desc *desc,
+extern int verity_hash(struct dm_verity *v, struct ahash_request *req,
 		       const u8 *data, size_t len, u8 *digest);
 
 extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8bf397729bbd..268edf402bbb 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1104,8 +1104,18 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 
 	__bio_clone_fast(clone, bio);
 
-	if (bio_integrity(bio)) {
-		int r = bio_integrity_clone(clone, bio, GFP_NOIO);
+	if (unlikely(bio_integrity(bio) != NULL)) {
+		int r;
+
+		if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
+			     !dm_target_passes_integrity(tio->ti->type))) {
+			DMWARN("%s: the target %s doesn't support integrity data.",
+				dm_device_name(tio->io->md),
+				tio->ti->type->name);
+			return -EIO;
+		}
+
+		r = bio_integrity_clone(clone, bio, GFP_NOIO);
 		if (r < 0)
 			return r;
 	}
@@ -1113,7 +1123,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 	bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
 	clone->bi_iter.bi_size = to_bytes(len);
 
-	if (bio_integrity(bio))
+	if (unlikely(bio_integrity(bio) != NULL))
 		bio_integrity_trim(clone, 0, len);
 
 	return 0;
@@ -1715,6 +1725,8 @@ static void event_callback(void *context)
  */
 static void __set_size(struct mapped_device *md, sector_t size)
 {
+	lockdep_assert_held(&md->suspend_lock);
+
 	set_capacity(md->disk, size);
 
 	i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
@@ -1822,13 +1834,13 @@ void dm_unlock_md_type(struct mapped_device *md)
 	mutex_unlock(&md->type_lock);
 }
 
-void dm_set_md_type(struct mapped_device *md, unsigned type)
+void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
 {
 	BUG_ON(!mutex_is_locked(&md->type_lock));
 	md->type = type;
 }
 
-unsigned dm_get_md_type(struct mapped_device *md)
+enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
 {
 	return md->type;
 }
@@ -1855,7 +1867,7 @@ EXPORT_SYMBOL_GPL(dm_get_queue_limits);
 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
 {
 	int r;
-	unsigned type = dm_get_md_type(md);
+	enum dm_queue_mode type = dm_get_md_type(md);
 
 	switch (type) {
 	case DM_TYPE_REQUEST_BASED:
@@ -1886,6 +1898,9 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
 		if (type == DM_TYPE_DAX_BIO_BASED)
 			queue_flag_set_unlocked(QUEUE_FLAG_DAX, md->queue);
 		break;
+	case DM_TYPE_NONE:
+		WARN_ON_ONCE(true);
+		break;
 	}
 
 	return 0;
@@ -2164,8 +2179,6 @@ static void unlock_fs(struct mapped_device *md)
  * If __dm_suspend returns 0, the device is completely quiescent
  * now. There is no request-processing activity. All new requests
  * are being added to md->deferred list.
- *
- * Caller must hold md->suspend_lock
  */
 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
 			unsigned suspend_flags, long task_state,
@@ -2183,6 +2196,8 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
 	 */
 	if (noflush)
 		set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+	else
+		pr_debug("%s: suspending with flush\n", dm_device_name(md));
 
 	/*
 	 * This gets reverted if there's an error later and the targets
@@ -2381,6 +2396,8 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
 {
 	struct dm_table *map = NULL;
 
+	lockdep_assert_held(&md->suspend_lock);
+
 	if (md->internal_suspend_count++)
 		return; /* nested internal suspend */
 
@@ -2571,7 +2588,7 @@ int dm_noflush_suspending(struct dm_target *ti)
 }
 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
 
-struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
+struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
 					    unsigned integrity, unsigned per_io_data_size)
 {
 	struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index f298b01f7ab3..38c84c0a35d4 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -64,7 +64,7 @@ void dm_table_presuspend_undo_targets(struct dm_table *t);
 void dm_table_postsuspend_targets(struct dm_table *t);
 int dm_table_resume_targets(struct dm_table *t);
 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
-unsigned dm_table_get_type(struct dm_table *t);
+enum dm_queue_mode dm_table_get_type(struct dm_table *t);
 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
@@ -76,8 +76,8 @@ struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
 
 void dm_lock_md_type(struct mapped_device *md);
 void dm_unlock_md_type(struct mapped_device *md);
-void dm_set_md_type(struct mapped_device *md, unsigned type);
-unsigned dm_get_md_type(struct mapped_device *md);
+void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
+enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
 
 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
@@ -204,7 +204,7 @@ void dm_kcopyd_exit(void);
 /*
  * Mempool operations
  */
-struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
+struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
 					    unsigned integrity, unsigned per_bio_data_size);
 void dm_free_md_mempools(struct dm_md_mempools *pools);
 
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 8589e0a14068..ea15d220ced7 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -378,7 +378,6 @@ struct dm_block_manager {
 
 struct dm_block_manager *dm_block_manager_create(struct block_device *bdev,
 						 unsigned block_size,
-						 unsigned cache_size,
 						 unsigned max_held_per_thread)
 {
 	int r;
diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h
index 3627d1b7667a..e728937f376a 100644
--- a/drivers/md/persistent-data/dm-block-manager.h
+++ b/drivers/md/persistent-data/dm-block-manager.h
@@ -33,7 +33,7 @@ void *dm_block_data(struct dm_block *b);
 struct dm_block_manager;
 struct dm_block_manager *dm_block_manager_create(
 	struct block_device *bdev, unsigned block_size,
-	unsigned cache_size, unsigned max_held_per_thread);
+	unsigned max_held_per_thread);
 void dm_block_manager_destroy(struct dm_block_manager *bm);
 
 unsigned dm_bm_block_size(struct dm_block_manager *bm);
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 02e2ee0d8a00..f21ce6a3d4cf 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -902,8 +902,12 @@ static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest,
 		else
 			*result_key = le64_to_cpu(ro_node(s)->keys[0]);
 
-		if (next_block || flags & INTERNAL_NODE)
-			block = value64(ro_node(s), i);
+		if (next_block || flags & INTERNAL_NODE) {
+			if (find_highest)
+				block = value64(ro_node(s), i);
+			else
+				block = value64(ro_node(s), 0);
+		}
 
 	} while (flags & INTERNAL_NODE);
 
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index b6194e082e48..26ba09282e7c 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -54,16 +54,6 @@
  */
 #define R5L_POOL_SIZE	4
 
-/*
- * r5c journal modes of the array: write-back or write-through.
- * write-through mode has identical behavior as existing log only
- * implementation.
- */
-enum r5c_journal_mode {
-	R5C_JOURNAL_MODE_WRITE_THROUGH = 0,
-	R5C_JOURNAL_MODE_WRITE_BACK = 1,
-};
-
 static char *r5c_journal_mode_str[] = {"write-through",
 				       "write-back"};
 /*
@@ -2526,40 +2516,56 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 	return ret;
 }
 
-static ssize_t r5c_journal_mode_store(struct mddev *mddev,
-				      const char *page, size_t length)
+/*
+ * Set journal cache mode on @mddev (external API initially needed by dm-raid).
+ *
+ * @mode as defined in 'enum r5c_journal_mode'.
+ *
+ */
+int r5c_journal_mode_set(struct mddev *mddev, int mode)
 {
 	struct r5conf *conf = mddev->private;
 	struct r5l_log *log = conf->log;
-	int val = -1, i;
-	int len = length;
 
 	if (!log)
 		return -ENODEV;
 
-	if (len && page[len - 1] == '\n')
-		len -= 1;
-	for (i = 0; i < ARRAY_SIZE(r5c_journal_mode_str); i++)
-		if (strlen(r5c_journal_mode_str[i]) == len &&
-		    strncmp(page, r5c_journal_mode_str[i], len) == 0) {
-			val = i;
-			break;
-		}
-	if (val < R5C_JOURNAL_MODE_WRITE_THROUGH ||
-	    val > R5C_JOURNAL_MODE_WRITE_BACK)
+	if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
+	    mode > R5C_JOURNAL_MODE_WRITE_BACK)
 		return -EINVAL;
 
 	if (raid5_calc_degraded(conf) > 0 &&
-	    val == R5C_JOURNAL_MODE_WRITE_BACK)
+	    mode == R5C_JOURNAL_MODE_WRITE_BACK)
 		return -EINVAL;
 
 	mddev_suspend(mddev);
-	conf->log->r5c_journal_mode = val;
+	conf->log->r5c_journal_mode = mode;
 	mddev_resume(mddev);
 
 	pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
-		 mdname(mddev), val, r5c_journal_mode_str[val]);
-	return length;
+		 mdname(mddev), mode, r5c_journal_mode_str[mode]);
+	return 0;
+}
+EXPORT_SYMBOL(r5c_journal_mode_set);
+
+static ssize_t r5c_journal_mode_store(struct mddev *mddev,
+				      const char *page, size_t length)
+{
+	int mode = ARRAY_SIZE(r5c_journal_mode_str);
+	size_t len = length;
+
+	if (len < 2)
+		return -EINVAL;
+
+	if (page[len - 1] == '\n')
+		len--;
+
+	while (mode--)
+		if (strlen(r5c_journal_mode_str[mode]) == len &&
+		    !strncmp(page, r5c_journal_mode_str[mode], len))
+			break;
+
+	return r5c_journal_mode_set(mddev, mode) ?: length;
 }
 
 struct md_sysfs_entry
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 625c7f16fd6b..f6536399677a 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -510,6 +510,16 @@ struct r5worker_group {
 	int stripes_cnt;
 };
 
+/*
+ * r5c journal modes of the array: write-back or write-through.
+ * write-through mode has identical behavior as existing log only
+ * implementation.
+ */
+enum r5c_journal_mode {
+	R5C_JOURNAL_MODE_WRITE_THROUGH = 0,
+	R5C_JOURNAL_MODE_WRITE_BACK = 1,
+};
+
 enum r5_cache_state {
 	R5_INACTIVE_BLOCKED,	/* release of inactive stripes blocked,
 				 * waiting for 25% to be free
@@ -741,4 +751,5 @@ extern struct stripe_head *
 raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
 			int previous, int noblock, int noquiesce);
 extern int raid5_calc_degraded(struct r5conf *conf);
+extern int r5c_journal_mode_set(struct mddev *mddev, int journal_mode);
 #endif