Merge tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "On top of the core changes, here are the block driver changes for this
  merge window:

   - NVMe changes:
        - NVMe over Fibre Channel protocol updates, which also reach
          over to drivers/scsi/lpfc (James Smart)
        - namespace revalidation support on the target (Anthony
          Iliopoulos)
        - gcc zero length array fix (Arnd Bergmann)
        - nvmet cleanups (Chaitanya Kulkarni)
        - misc cleanups and fixes (me, Keith Busch, Sagi Grimberg)
        - use a SRQ per completion vector (Max Gurtovoy)
        - fix handling of runtime changes to the queue count (Weiping
          Zhang)
        - t10 protection information support for nvme-rdma and
          nvmet-rdma (Israel Rukshin and Max Gurtovoy)
        - target side AEN improvements (Chaitanya Kulkarni)
        - various fixes and minor improvements all over, icluding the
          nvme part of the lpfc driver"

   - Floppy code cleanup series (Willy, Denis)

   - Floppy contention fix (Jiri)

   - Loop CONFIGURE support (Martijn)

   - bcache fixes/improvements (Coly, Joe, Colin)

   - q->queuedata cleanups (Christoph)

   - Get rid of ioctl_by_bdev (Christoph, Stefan)

   - md/raid5 allocation fixes (Coly)

   - zero length array fixes (Gustavo)

   - swim3 task state fix (Xu)"

* tag 'for-5.8/drivers-2020-06-01' of git://git.kernel.dk/linux-block: (166 commits)
  bcache: configure the asynchronous registertion to be experimental
  bcache: asynchronous devices registration
  bcache: fix refcount underflow in bcache_device_free()
  bcache: Convert pr_<level> uses to a more typical style
  bcache: remove redundant variables i and n
  lpfc: Fix return value in __lpfc_nvme_ls_abort
  lpfc: fix axchg pointer reference after free and double frees
  lpfc: Fix pointer checks and comments in LS receive refactoring
  nvme: set dma alignment to qword
  nvmet: cleanups the loop in nvmet_async_events_process
  nvmet: fix memory leak when removing namespaces and controllers concurrently
  nvmet-rdma: add metadata/T10-PI support
  nvmet: add metadata support for block devices
  nvmet: add metadata/T10-PI support
  nvme: add Metadata Capabilities enumerations
  nvmet: rename nvmet_check_data_len to nvmet_check_transfer_len
  nvmet: rename nvmet_rw_len to nvmet_rw_data_len
  nvmet: add metadata characteristics for a namespace
  nvme-rdma: add metadata/T10-PI support
  nvme-rdma: introduce nvme_rdma_sgl structure
  ...

18 files changed, 299 insertions, 153 deletions

diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index 6dfa653d30db..bf7dd96db9b3 100644
--- a/drivers/md/bcache/Kconfig
+++ b/drivers/md/bcache/Kconfig
@@ -26,3 +26,12 @@ config BCACHE_CLOSURES_DEBUG
 	Keeps all active closures in a linked list and provides a debugfs
 	interface to list them, which makes it possible to see asynchronous
 	operations that get stuck.
+
+config BCACHE_ASYNC_REGISTRAION
+	bool "Asynchronous device registration (EXPERIMENTAL)"
+	depends on BCACHE
+	help
+	Add a sysfs file /sys/fs/bcache/register_async. Writing registering
+	device path into this file will returns immediately and the real
+	registration work is handled in kernel work queue in asynchronous
+	way.
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 74a9849ea164..221e0191b687 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -176,7 +176,7 @@
  * - updates to non leaf nodes just happen synchronously (see btree_split()).
  */
 
-#define pr_fmt(fmt) "bcache: %s() " fmt "\n", __func__
+#define pr_fmt(fmt) "bcache: %s() " fmt, __func__
 
 #include <linux/bcache.h>
 #include <linux/bio.h>
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 4385303836d8..4995fcaefe29 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -6,7 +6,7 @@
  * Copyright 2012 Google, Inc.
  */
 
-#define pr_fmt(fmt) "bcache: %s() " fmt "\n", __func__
+#define pr_fmt(fmt) "bcache: %s() " fmt, __func__
 
 #include "util.h"
 #include "bset.h"
@@ -31,7 +31,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned int set)
 		if (b->ops->key_dump)
 			b->ops->key_dump(b, k);
 		else
-			pr_err("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
+			pr_cont("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
 
 		if (next < bset_bkey_last(i) &&
 		    bkey_cmp(k, b->ops->is_extents ?
@@ -1225,7 +1225,7 @@ static void btree_mergesort(struct btree_keys *b, struct bset *out,
 
 	out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
 
-	pr_debug("sorted %i keys", out->keys);
+	pr_debug("sorted %i keys\n", out->keys);
 }
 
 static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 72856e5f23a3..39de94edd73a 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -619,7 +619,7 @@ retry:
 	 * and BTREE_NODE_journal_flush bit cleared by btree_flush_write().
 	 */
 	if (btree_node_journal_flush(b)) {
-		pr_debug("bnode %p is flushing by journal, retry", b);
+		pr_debug("bnode %p is flushing by journal, retry\n", b);
 		mutex_unlock(&b->write_lock);
 		udelay(1);
 		goto retry;
@@ -802,7 +802,7 @@ int bch_btree_cache_alloc(struct cache_set *c)
 	c->shrink.batch = c->btree_pages * 2;
 
 	if (register_shrinker(&c->shrink))
-		pr_warn("bcache: %s: could not register shrinker",
+		pr_warn("bcache: %s: could not register shrinker\n",
 				__func__);
 
 	return 0;
@@ -1054,7 +1054,7 @@ retry:
 	 */
 	if (btree_node_journal_flush(b)) {
 		mutex_unlock(&b->write_lock);
-		pr_debug("bnode %p journal_flush set, retry", b);
+		pr_debug("bnode %p journal_flush set, retry\n", b);
 		udelay(1);
 		goto retry;
 	}
@@ -1798,7 +1798,7 @@ static void bch_btree_gc(struct cache_set *c)
 			schedule_timeout_interruptible(msecs_to_jiffies
 						       (GC_SLEEP_MS));
 		else if (ret)
-			pr_warn("gc failed!");
+			pr_warn("gc failed!\n");
 	} while (ret && !test_bit(CACHE_SET_IO_DISABLE, &c->flags));
 
 	bch_btree_gc_finish(c);
@@ -1907,10 +1907,8 @@ static int bch_btree_check_thread(void *arg)
 	struct btree_iter iter;
 	struct bkey *k, *p;
 	int cur_idx, prev_idx, skip_nr;
-	int i, n;
 
 	k = p = NULL;
-	i = n = 0;
 	cur_idx = prev_idx = 0;
 	ret = 0;
 
@@ -2045,7 +2043,7 @@ int bch_btree_check(struct cache_set *c)
 				    &check_state->infos[i],
 				    name);
 		if (IS_ERR(check_state->infos[i].thread)) {
-			pr_err("fails to run thread bch_btrchk[%d]", i);
+			pr_err("fails to run thread bch_btrchk[%d]\n", i);
 			for (--i; i >= 0; i--)
 				kthread_stop(check_state->infos[i].thread);
 			ret = -ENOMEM;
@@ -2456,7 +2454,7 @@ int bch_btree_insert(struct cache_set *c, struct keylist *keys,
 	if (ret) {
 		struct bkey *k;
 
-		pr_err("error %i", ret);
+		pr_err("error %i\n", ret);
 
 		while ((k = bch_keylist_pop(keys)))
 			bkey_put(c, k);
@@ -2744,7 +2742,7 @@ struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c,
 			break;
 
 		if (bkey_cmp(&buf->last_scanned, end) >= 0) {
-			pr_debug("scan finished");
+			pr_debug("scan finished\n");
 			break;
 		}
 
diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c
index 886710043025..9162af5bb6ec 100644
--- a/drivers/md/bcache/extents.c
+++ b/drivers/md/bcache/extents.c
@@ -130,18 +130,18 @@ static void bch_bkey_dump(struct btree_keys *keys, const struct bkey *k)
 	char buf[80];
 
 	bch_extent_to_text(buf, sizeof(buf), k);
-	pr_err(" %s", buf);
+	pr_cont(" %s", buf);
 
 	for (j = 0; j < KEY_PTRS(k); j++) {
 		size_t n = PTR_BUCKET_NR(b->c, k, j);
 
-		pr_err(" bucket %zu", n);
+		pr_cont(" bucket %zu", n);
 		if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
-			pr_err(" prio %i",
-			       PTR_BUCKET(b->c, k, j)->prio);
+			pr_cont(" prio %i",
+				PTR_BUCKET(b->c, k, j)->prio);
 	}
 
-	pr_err(" %s\n", bch_ptr_status(b->c, k));
+	pr_cont(" %s\n", bch_ptr_status(b->c, k));
 }
 
 /* Btree ptrs */
@@ -553,7 +553,7 @@ static bool bch_extent_bad(struct btree_keys *bk, const struct bkey *k)
 
 		if (stale && KEY_DIRTY(k)) {
 			bch_extent_to_text(buf, sizeof(buf), k);
-			pr_info("stale dirty pointer, stale %u, key: %s",
+			pr_info("stale dirty pointer, stale %u, key: %s\n",
 				stale, buf);
 		}
 
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c
index 4d93f07f63e5..b25ee33b0d0b 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -65,14 +65,14 @@ void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio)
 	 * we shouldn't count failed REQ_RAHEAD bio to dc->io_errors.
 	 */
 	if (bio->bi_opf & REQ_RAHEAD) {
-		pr_warn_ratelimited("%s: Read-ahead I/O failed on backing device, ignore",
+		pr_warn_ratelimited("%s: Read-ahead I/O failed on backing device, ignore\n",
 				    dc->backing_dev_name);
 		return;
 	}
 
 	errors = atomic_add_return(1, &dc->io_errors);
 	if (errors < dc->error_limit)
-		pr_err("%s: IO error on backing device, unrecoverable",
+		pr_err("%s: IO error on backing device, unrecoverable\n",
 			dc->backing_dev_name);
 	else
 		bch_cached_dev_error(dc);
@@ -123,12 +123,12 @@ void bch_count_io_errors(struct cache *ca,
 		errors >>= IO_ERROR_SHIFT;
 
 		if (errors < ca->set->error_limit)
-			pr_err("%s: IO error on %s%s",
+			pr_err("%s: IO error on %s%s\n",
 			       ca->cache_dev_name, m,
 			       is_read ? ", recovering." : ".");
 		else
 			bch_cache_set_error(ca->set,
-					    "%s: too many IO errors %s",
+					    "%s: too many IO errors %s\n",
 					    ca->cache_dev_name, m);
 	}
 }
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 0e3ff9745ac7..90aac4e2333f 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -47,7 +47,7 @@ static int journal_read_bucket(struct cache *ca, struct list_head *list,
 
 	closure_init_stack(&cl);
 
-	pr_debug("reading %u", bucket_index);
+	pr_debug("reading %u\n", bucket_index);
 
 	while (offset < ca->sb.bucket_size) {
 reread:		left = ca->sb.bucket_size - offset;
@@ -78,13 +78,13 @@ reread:		left = ca->sb.bucket_size - offset;
 			size_t blocks, bytes = set_bytes(j);
 
 			if (j->magic != jset_magic(&ca->sb)) {
-				pr_debug("%u: bad magic", bucket_index);
+				pr_debug("%u: bad magic\n", bucket_index);
 				return ret;
 			}
 
 			if (bytes > left << 9 ||
 			    bytes > PAGE_SIZE << JSET_BITS) {
-				pr_info("%u: too big, %zu bytes, offset %u",
+				pr_info("%u: too big, %zu bytes, offset %u\n",
 					bucket_index, bytes, offset);
 				return ret;
 			}
@@ -93,7 +93,7 @@ reread:		left = ca->sb.bucket_size - offset;
 				goto reread;
 
 			if (j->csum != csum_set(j)) {
-				pr_info("%u: bad csum, %zu bytes, offset %u",
+				pr_info("%u: bad csum, %zu bytes, offset %u\n",
 					bucket_index, bytes, offset);
 				return ret;
 			}
@@ -190,7 +190,7 @@ int bch_journal_read(struct cache_set *c, struct list_head *list)
 		uint64_t seq;
 
 		bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
-		pr_debug("%u journal buckets", ca->sb.njournal_buckets);
+		pr_debug("%u journal buckets\n", ca->sb.njournal_buckets);
 
 		/*
 		 * Read journal buckets ordered by golden ratio hash to quickly
@@ -215,7 +215,7 @@ int bch_journal_read(struct cache_set *c, struct list_head *list)
 		 * If that fails, check all the buckets we haven't checked
 		 * already
 		 */
-		pr_debug("falling back to linear search");
+		pr_debug("falling back to linear search\n");
 
 		for (l = find_first_zero_bit(bitmap, ca->sb.njournal_buckets);
 		     l < ca->sb.njournal_buckets;
@@ -233,7 +233,7 @@ bsearch:
 		/* Binary search */
 		m = l;
 		r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
-		pr_debug("starting binary search, l %u r %u", l, r);
+		pr_debug("starting binary search, l %u r %u\n", l, r);
 
 		while (l + 1 < r) {
 			seq = list_entry(list->prev, struct journal_replay,
@@ -253,7 +253,7 @@ bsearch:
 		 * Read buckets in reverse order until we stop finding more
 		 * journal entries
 		 */
-		pr_debug("finishing up: m %u njournal_buckets %u",
+		pr_debug("finishing up: m %u njournal_buckets %u\n",
 			 m, ca->sb.njournal_buckets);
 		l = m;
 
@@ -370,10 +370,10 @@ int bch_journal_replay(struct cache_set *s, struct list_head *list)
 
 		if (n != i->j.seq) {
 			if (n == start && is_discard_enabled(s))
-				pr_info("bcache: journal entries %llu-%llu may be discarded! (replaying %llu-%llu)",
+				pr_info("journal entries %llu-%llu may be discarded! (replaying %llu-%llu)\n",
 					n, i->j.seq - 1, start, end);
 			else {
-				pr_err("bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)",
+				pr_err("journal entries %llu-%llu missing! (replaying %llu-%llu)\n",
 					n, i->j.seq - 1, start, end);
 				ret = -EIO;
 				goto err;
@@ -403,7 +403,7 @@ int bch_journal_replay(struct cache_set *s, struct list_head *list)
 		entries++;
 	}
 
-	pr_info("journal replay done, %i keys in %i entries, seq %llu",
+	pr_info("journal replay done, %i keys in %i entries, seq %llu\n",
 		keys, entries, end);
 err:
 	while (!list_empty(list)) {
@@ -481,7 +481,7 @@ static void btree_flush_write(struct cache_set *c)
 			break;
 
 		if (btree_node_journal_flush(b))
-			pr_err("BUG: flush_write bit should not be set here!");
+			pr_err("BUG: flush_write bit should not be set here!\n");
 
 		mutex_lock(&b->write_lock);
 
@@ -534,13 +534,13 @@ static void btree_flush_write(struct cache_set *c)
 	for (i = 0; i < nr; i++) {
 		b = btree_nodes[i];
 		if (!b) {
-			pr_err("BUG: btree_nodes[%d] is NULL", i);
+			pr_err("BUG: btree_nodes[%d] is NULL\n", i);
 			continue;
 		}
 
 		/* safe to check without holding b->write_lock */
 		if (!btree_node_journal_flush(b)) {
-			pr_err("BUG: bnode %p: journal_flush bit cleaned", b);
+			pr_err("BUG: bnode %p: journal_flush bit cleaned\n", b);
 			continue;
 		}
 
@@ -548,14 +548,14 @@ static void btree_flush_write(struct cache_set *c)
 		if (!btree_current_write(b)->journal) {
 			clear_bit(BTREE_NODE_journal_flush, &b->flags);
 			mutex_unlock(&b->write_lock);
-			pr_debug("bnode %p: written by others", b);
+			pr_debug("bnode %p: written by others\n", b);
 			continue;
 		}
 
 		if (!btree_node_dirty(b)) {
 			clear_bit(BTREE_NODE_journal_flush, &b->flags);
 			mutex_unlock(&b->write_lock);
-			pr_debug("bnode %p: dirty bit cleaned by others", b);
+			pr_debug("bnode %p: dirty bit cleaned by others\n", b);
 			continue;
 		}
 
@@ -716,7 +716,7 @@ void bch_journal_next(struct journal *j)
 	j->cur->data->keys	= 0;
 
 	if (fifo_full(&j->pin))
-		pr_debug("journal_pin full (%zu)", fifo_used(&j->pin));
+		pr_debug("journal_pin full (%zu)\n", fifo_used(&j->pin));
 }
 
 static void journal_write_endio(struct bio *bio)
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 22b483527176..7acf024e99f3 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -110,7 +110,7 @@ static void bch_data_invalidate(struct closure *cl)
 	struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
 	struct bio *bio = op->bio;
 
-	pr_debug("invalidating %i sectors from %llu",
+	pr_debug("invalidating %i sectors from %llu\n",
 		 bio_sectors(bio), (uint64_t) bio->bi_iter.bi_sector);
 
 	while (bio_sectors(bio)) {
@@ -396,7 +396,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 
 	if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
 	    bio_sectors(bio) & (c->sb.block_size - 1)) {
-		pr_debug("skipping unaligned io");
+		pr_debug("skipping unaligned io\n");
 		goto skip;
 	}
 
@@ -650,7 +650,7 @@ static void backing_request_endio(struct bio *bio)
 		 */
 		if (unlikely(s->iop.writeback &&
 			     bio->bi_opf & REQ_PREFLUSH)) {
-			pr_err("Can't flush %s: returned bi_status %i",
+			pr_err("Can't flush %s: returned bi_status %i\n",
 				dc->backing_dev_name, bio->bi_status);
 		} else {
 			/* set to orig_bio->bi_status in bio_complete() */
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index d98354fa28e3..f9975c22bf7e 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -89,7 +89,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
 	for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
 		sb->d[i] = le64_to_cpu(s->d[i]);
 
-	pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
+	pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u\n",
 		 sb->version, sb->flags, sb->seq, sb->keys);
 
 	err = "Not a bcache superblock (bad offset)";
@@ -234,7 +234,7 @@ static void __write_super(struct cache_sb *sb, struct cache_sb_disk *out,
 
 	out->csum = csum_set(out);
 
-	pr_debug("ver %llu, flags %llu, seq %llu",
+	pr_debug("ver %llu, flags %llu, seq %llu\n",
 		 sb->version, sb->flags, sb->seq);
 
 	submit_bio(bio);
@@ -365,11 +365,11 @@ static void uuid_io(struct cache_set *c, int op, unsigned long op_flags,
 	}
 
 	bch_extent_to_text(buf, sizeof(buf), k);
-	pr_debug("%s UUIDs at %s", op == REQ_OP_WRITE ? "wrote" : "read", buf);
+	pr_debug("%s UUIDs at %s\n", op == REQ_OP_WRITE ? "wrote" : "read", buf);
 
 	for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
 		if (!bch_is_zero(u->uuid, 16))
-			pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
+			pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u\n",
 				 u - c->uuids, u->uuid, u->label,
 				 u->first_reg, u->last_reg, u->invalidated);
 
@@ -534,7 +534,7 @@ int bch_prio_write(struct cache *ca, bool wait)
 	struct bucket *b;
 	struct closure cl;
 
-	pr_debug("free_prio=%zu, free_none=%zu, free_inc=%zu",
+	pr_debug("free_prio=%zu, free_none=%zu, free_inc=%zu\n",
 		 fifo_used(&ca->free[RESERVE_PRIO]),
 		 fifo_used(&ca->free[RESERVE_NONE]),
 		 fifo_used(&ca->free_inc));
@@ -629,12 +629,12 @@ static int prio_read(struct cache *ca, uint64_t bucket)
 
 			if (p->csum !=
 			    bch_crc64(&p->magic, bucket_bytes(ca) - 8)) {
-				pr_warn("bad csum reading priorities");
+				pr_warn("bad csum reading priorities\n");
 				goto out;
 			}
 
 			if (p->magic != pset_magic(&ca->sb)) {
-				pr_warn("bad magic reading priorities");
+				pr_warn("bad magic reading priorities\n");
 				goto out;
 			}
 
@@ -728,11 +728,11 @@ static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
 
 	ret = sysfs_create_link(&d->kobj, &c->kobj, "cache");
 	if (ret < 0)
-		pr_err("Couldn't create device -> cache set symlink");
+		pr_err("Couldn't create device -> cache set symlink\n");
 
 	ret = sysfs_create_link(&c->kobj, &d->kobj, d->name);
 	if (ret < 0)
-		pr_err("Couldn't create cache set -> device symlink");
+		pr_err("Couldn't create cache set -> device symlink\n");
 
 	clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
 }
@@ -789,15 +789,17 @@ static void bcache_device_free(struct bcache_device *d)
 	lockdep_assert_held(&bch_register_lock);
 
 	if (disk)
-		pr_info("%s stopped", disk->disk_name);
+		pr_info("%s stopped\n", disk->disk_name);
 	else
-		pr_err("bcache device (NULL gendisk) stopped");
+		pr_err("bcache device (NULL gendisk) stopped\n");
 
 	if (d->c)
 		bcache_device_detach(d);
 
 	if (disk) {
-		if (disk->flags & GENHD_FL_UP)
+		bool disk_added = (disk->flags & GENHD_FL_UP) != 0;
+
+		if (disk_added)
 			del_gendisk(disk);
 
 		if (disk->queue)
@@ -805,7 +807,8 @@ static void bcache_device_free(struct bcache_device *d)
 
 		ida_simple_remove(&bcache_device_idx,
 				  first_minor_to_idx(disk->first_minor));
-		put_disk(disk);
+		if (disk_added)
+			put_disk(disk);
 	}
 
 	bioset_exit(&d->bio_split);
@@ -830,7 +833,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 	d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
 
 	if (!d->nr_stripes || d->nr_stripes > max_stripes) {
-		pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)",
+		pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)\n",
 			(unsigned int)d->nr_stripes);
 		return -ENOMEM;
 	}
@@ -928,11 +931,11 @@ static int cached_dev_status_update(void *arg)
 			dc->offline_seconds = 0;
 
 		if (dc->offline_seconds >= BACKING_DEV_OFFLINE_TIMEOUT) {
-			pr_err("%s: device offline for %d seconds",
+			pr_err("%s: device offline for %d seconds\n",
 			       dc->backing_dev_name,
 			       BACKING_DEV_OFFLINE_TIMEOUT);
-			pr_err("%s: disable I/O request due to backing "
-			       "device offline", dc->disk.name);
+			pr_err("%s: disable I/O request due to backing device offline\n",
+			       dc->disk.name);
 			dc->io_disable = true;
 			/* let others know earlier that io_disable is true */
 			smp_mb();
@@ -959,7 +962,7 @@ int bch_cached_dev_run(struct cached_dev *dc)
 	};
 
 	if (dc->io_disable) {
-		pr_err("I/O disabled on cached dev %s",
+		pr_err("I/O disabled on cached dev %s\n",
 		       dc->backing_dev_name);
 		kfree(env[1]);
 		kfree(env[2]);
@@ -971,7 +974,7 @@ int bch_cached_dev_run(struct cached_dev *dc)
 		kfree(env[1]);
 		kfree(env[2]);
 		kfree(buf);
-		pr_info("cached dev %s is running already",
+		pr_info("cached dev %s is running already\n",
 		       dc->backing_dev_name);
 		return -EBUSY;
 	}
@@ -1001,16 +1004,14 @@ int bch_cached_dev_run(struct cached_dev *dc)
 	if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
 	    sysfs_create_link(&disk_to_dev(d->disk)->kobj,
 			      &d->kobj, "bcache")) {
-		pr_err("Couldn't create bcache dev <-> disk sysfs symlinks");
+		pr_err("Couldn't create bcache dev <-> disk sysfs symlinks\n");
 		return -ENOMEM;
 	}
 
 	dc->status_update_thread = kthread_run(cached_dev_status_update,
 					       dc, "bcache_status_update");
 	if (IS_ERR(dc->status_update_thread)) {
-		pr_warn("failed to create bcache_status_update kthread, "
-			"continue to run without monitoring backing "
-			"device status");
+		pr_warn("failed to create bcache_status_update kthread, continue to run without monitoring backing device status\n");
 	}
 
 	return 0;
@@ -1036,7 +1037,7 @@ static void cancel_writeback_rate_update_dwork(struct cached_dev *dc)
 	} while (time_out > 0);
 
 	if (time_out == 0)
-		pr_warn("give up waiting for dc->writeback_write_update to quit");
+		pr_warn("give up waiting for dc->writeback_write_update to quit\n");
 
 	cancel_delayed_work_sync(&dc->writeback_rate_update);
 }
@@ -1077,7 +1078,7 @@ static void cached_dev_detach_finish(struct work_struct *w)
 
 	mutex_unlock(&bch_register_lock);
 
-	pr_info("Caching disabled for %s", dc->backing_dev_name);
+	pr_info("Caching disabled for %s\n", dc->backing_dev_name);
 
 	/* Drop ref we took in cached_dev_detach() */
 	closure_put(&dc->disk.cl);
@@ -1117,20 +1118,20 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 		return -ENOENT;
 
 	if (dc->disk.c) {
-		pr_err("Can't attach %s: already attached",
+		pr_err("Can't attach %s: already attached\n",
 		       dc->backing_dev_name);
 		return -EINVAL;
 	}
 
 	if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
-		pr_err("Can't attach %s: shutting down",
+		pr_err("Can't attach %s: shutting down\n",
 		       dc->backing_dev_name);
 		return -EINVAL;
 	}
 
 	if (dc->sb.block_size < c->sb.block_size) {
 		/* Will die */
-		pr_err("Couldn't attach %s: block size less than set's block size",
+		pr_err("Couldn't attach %s: block size less than set's block size\n",
 		       dc->backing_dev_name);
 		return -EINVAL;
 	}
@@ -1138,7 +1139,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	/* Check whether already attached */
 	list_for_each_entry_safe(exist_dc, t, &c->cached_devs, list) {
 		if (!memcmp(dc->sb.uuid, exist_dc->sb.uuid, 16)) {
-			pr_err("Tried to attach %s but duplicate UUID already attached",
+			pr_err("Tried to attach %s but duplicate UUID already attached\n",
 				dc->backing_dev_name);
 
 			return -EINVAL;
@@ -1157,14 +1158,14 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 
 	if (!u) {
 		if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
-			pr_err("Couldn't find uuid for %s in set",
+			pr_err("Couldn't find uuid for %s in set\n",
 			       dc->backing_dev_name);
 			return -ENOENT;
 		}
 
 		u = uuid_find_empty(c);
 		if (!u) {
-			pr_err("Not caching %s, no room for UUID",
+			pr_err("Not caching %s, no room for UUID\n",
 			       dc->backing_dev_name);
 			return -EINVAL;
 		}
@@ -1210,7 +1211,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	down_write(&dc->writeback_lock);
 	if (bch_cached_dev_writeback_start(dc)) {
 		up_write(&dc->writeback_lock);
-		pr_err("Couldn't start writeback facilities for %s",
+		pr_err("Couldn't start writeback facilities for %s\n",
 		       dc->disk.disk->disk_name);
 		return -ENOMEM;
 	}
@@ -1233,7 +1234,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 		 */
 		kthread_stop(dc->writeback_thread);
 		cancel_writeback_rate_update_dwork(dc);
-		pr_err("Couldn't run cached device %s",
+		pr_err("Couldn't run cached device %s\n",
 		       dc->backing_dev_name);
 		return ret;
 	}
@@ -1244,7 +1245,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	/* Allow the writeback thread to proceed */
 	up_write(&dc->writeback_lock);
 
-	pr_info("Caching %s as %s on set %pU",
+	pr_info("Caching %s as %s on set %pU\n",
 		dc->backing_dev_name,
 		dc->disk.disk->disk_name,
 		dc->disk.c->sb.set_uuid);
@@ -1384,7 +1385,7 @@ static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
 	if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
 		goto err;
 
-	pr_info("registered backing device %s", dc->backing_dev_name);
+	pr_info("registered backing device %s\n", dc->backing_dev_name);
 
 	list_add(&dc->list, &uncached_devices);
 	/* attach to a matched cache set if it exists */
@@ -1401,7 +1402,7 @@ static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
 
 	return 0;
 err:
-	pr_notice("error %s: %s", dc->backing_dev_name, err);
+	pr_notice("error %s: %s\n", dc->backing_dev_name, err);
 	bcache_device_stop(&dc->disk);
 	return ret;
 }
@@ -1497,7 +1498,7 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size)
 
 	u = uuid_find_empty(c);
 	if (!u) {
-		pr_err("Can't create volume, no room for UUID");
+		pr_err("Can't create volume, no room for UUID\n");
 		return -EINVAL;
 	}
 
@@ -1523,7 +1524,7 @@ bool bch_cached_dev_error(struct cached_dev *dc)
 	smp_mb();
 
 	pr_err("stop %s: too many IO errors on backing device %s\n",
-		dc->disk.disk->disk_name, dc->backing_dev_name);
+	       dc->disk.disk->disk_name, dc->backing_dev_name);
 
 	bcache_device_stop(&dc->disk);
 	return true;
@@ -1534,6 +1535,7 @@ bool bch_cached_dev_error(struct cached_dev *dc)
 __printf(2, 3)
 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
 {
+	struct va_format vaf;
 	va_list args;
 
 	if (c->on_error != ON_ERROR_PANIC &&
@@ -1541,20 +1543,22 @@ bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
 		return false;
 
 	if (test_and_set_bit(CACHE_SET_IO_DISABLE, &c->flags))
-		pr_info("CACHE_SET_IO_DISABLE already set");
+		pr_info("CACHE_SET_IO_DISABLE already set\n");
 
 	/*
 	 * XXX: we can be called from atomic context
 	 * acquire_console_sem();
 	 */
 
-	pr_err("bcache: error on %pU: ", c->sb.set_uuid);
-
 	va_start(args, fmt);
-	vprintk(fmt, args);
-	va_end(args);
 
-	pr_err(", disabling caching\n");
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	pr_err("error on %pU: %pV, disabling caching\n",
+	       c->sb.set_uuid, &vaf);
+
+	va_end(args);
 
 	if (c->on_error == ON_ERROR_PANIC)
 		panic("panic forced after error\n");
@@ -1606,7 +1610,7 @@ static void cache_set_free(struct closure *cl)
 	list_del(&c->list);
 	mutex_unlock(&bch_register_lock);
 
-	pr_info("Cache set %pU unregistered", c->sb.set_uuid);
+	pr_info("Cache set %pU unregistered\n", c->sb.set_uuid);
 	wake_up(&unregister_wait);
 
 	closure_debug_destroy(&c->cl);
@@ -1677,7 +1681,7 @@ static void conditional_stop_bcache_device(struct cache_set *c,
 					   struct cached_dev *dc)
 {
 	if (dc->stop_when_cache_set_failed == BCH_CACHED_DEV_STOP_ALWAYS) {
-		pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.",
+		pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.\n",
 			d->disk->disk_name, c->sb.set_uuid);
 		bcache_device_stop(d);
 	} else if (atomic_read(&dc->has_dirty)) {
@@ -1685,7 +1689,7 @@ static void conditional_stop_bcache_device(struct cache_set *c,
 		 * dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO
 		 * and dc->has_dirty == 1
 		 */
-		pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.",
+		pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.\n",
 			d->disk->disk_name);
 		/*
 		 * There might be a small time gap that cache set is
@@ -1707,7 +1711,7 @@ static void conditional_stop_bcache_device(struct cache_set *c,
 		 * dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO
 		 * and dc->has_dirty == 0
 		 */
-		pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is clean, keep it alive.",
+		pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is clean, keep it alive.\n",
 			d->disk->disk_name);
 	}
 }
@@ -1874,7 +1878,7 @@ static int run_cache_set(struct cache_set *c)
 		if (bch_journal_read(c, &journal))
 			goto err;
 
-		pr_debug("btree_journal_read() done");
+		pr_debug("btree_journal_read() done\n");
 
 		err = "no journal entries found";
 		if (list_empty(&journal))
@@ -1920,7 +1924,7 @@ static int run_cache_set(struct cache_set *c)
 
 		bch_journal_mark(c, &journal);
 		bch_initial_gc_finish(c);
-		pr_debug("btree_check() done");
+		pr_debug("btree_check() done\n");
 
 		/*
 		 * bcache_journal_next() can't happen sooner, or
@@ -1951,7 +1955,7 @@ static int run_cache_set(struct cache_set *c)
 		if (bch_journal_replay(c, &journal))
 			goto err;
 	} else {
-		pr_notice("invalidating existing data");
+		pr_notice("invalidating existing data\n");
 
 		for_each_cache(ca, c, i) {
 			unsigned int j;
@@ -2085,7 +2089,7 @@ found:
 		memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
 		c->sb.flags             = ca->sb.flags;
 		c->sb.seq		= ca->sb.seq;
-		pr_debug("set version = %llu", c->sb.version);
+		pr_debug("set version = %llu\n", c->sb.version);
 	}
 
 	kobject_get(&ca->kobj);
@@ -2247,7 +2251,7 @@ err_btree_alloc:
 err_free:
 	module_put(THIS_MODULE);
 	if (err)
-		pr_notice("error %s: %s", ca->cache_dev_name, err);
+		pr_notice("error %s: %s\n", ca->cache_dev_name, err);
 	return ret;
 }
 
@@ -2301,14 +2305,14 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
 		goto out;
 	}
 
-	pr_info("registered cache device %s", ca->cache_dev_name);
+	pr_info("registered cache device %s\n", ca->cache_dev_name);
 
 out:
 	kobject_put(&ca->kobj);
 
 err:
 	if (err)
-		pr_notice("error %s: %s", ca->cache_dev_name, err);
+		pr_notice("error %s: %s\n", ca->cache_dev_name, err);
 
 	return ret;
 }
@@ -2323,6 +2327,7 @@ static ssize_t bch_pending_bdevs_cleanup(struct kobject *k,
 
 kobj_attribute_write(register,		register_bcache);
 kobj_attribute_write(register_quiet,	register_bcache);
+kobj_attribute_write(register_async,	register_bcache);
 kobj_attribute_write(pendings_cleanup,	bch_pending_bdevs_cleanup);
 
 static bool bch_is_open_backing(struct block_device *bdev)
@@ -2358,6 +2363,83 @@ static bool bch_is_open(struct block_device *bdev)
 	return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
 }
 
+struct async_reg_args {
+	struct work_struct reg_work;
+	char *path;
+	struct cache_sb *sb;
+	struct cache_sb_disk *sb_disk;
+	struct block_device *bdev;
+};
+
+static void register_bdev_worker(struct work_struct *work)
+{
+	int fail = false;
+	struct async_reg_args *args =
+		container_of(work, struct async_reg_args, reg_work);
+	struct cached_dev *dc;
+
+	dc = kzalloc(sizeof(*dc), GFP_KERNEL);
+	if (!dc) {
+		fail = true;
+		put_page(virt_to_page(args->sb_disk));
+		blkdev_put(args->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+		goto out;
+	}
+
+	mutex_lock(&bch_register_lock);
+	if (register_bdev(args->sb, args->sb_disk, args->bdev, dc) < 0)
+		fail = true;
+	mutex_unlock(&bch_register_lock);
+
+out:
+	if (fail)
+		pr_info("error %s: fail to register backing device\n",
+			args->path);
+	kfree(args->sb);
+	kfree(args->path);
+	kfree(args);
+	module_put(THIS_MODULE);
+}
+
+static void register_cache_worker(struct work_struct *work)
+{
+	int fail = false;
+	struct async_reg_args *args =
+		container_of(work, struct async_reg_args, reg_work);
+	struct cache *ca;
+
+	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+	if (!ca) {
+		fail = true;
+		put_page(virt_to_page(args->sb_disk));
+		blkdev_put(args->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+		goto out;
+	}
+
+	/* blkdev_put() will be called in bch_cache_release() */
+	if (register_cache(args->sb, args->sb_disk, args->bdev, ca) != 0)
+		fail = true;
+
+out:
+	if (fail)
+		pr_info("error %s: fail to register cache device\n",
+			args->path);
+	kfree(args->sb);
+	kfree(args->path);
+	kfree(args);
+	module_put(THIS_MODULE);
+}
+
+static void register_device_aync(struct async_reg_args *args)
+{
+	if (SB_IS_BDEV(args->sb))
+		INIT_WORK(&args->reg_work, register_bdev_worker);
+	else
+		INIT_WORK(&args->reg_work, register_cache_worker);
+
+	queue_work(system_wq, &args->reg_work);
+}
+
 static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 			       const char *buffer, size_t size)
 {
@@ -2420,6 +2502,26 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 		goto out_blkdev_put;
 
 	err = "failed to register device";
+	if (attr == &ksysfs_register_async) {
+		/* register in asynchronous way */
+		struct async_reg_args *args =
+			kzalloc(sizeof(struct async_reg_args), GFP_KERNEL);
+
+		if (!args) {
+			ret = -ENOMEM;
+			err = "cannot allocate memory";
+			goto out_put_sb_page;
+		}
+
+		args->path	= path;
+		args->sb	= sb;
+		args->sb_disk	= sb_disk;
+		args->bdev	= bdev;
+		register_device_aync(args);
+		/* No wait and returns to user space */
+		goto async_done;
+	}
+
 	if (SB_IS_BDEV(sb)) {
 		struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
 
@@ -2447,6 +2549,7 @@ done:
 	kfree(sb);
 	kfree(path);
 	module_put(THIS_MODULE);
+async_done:
 	return size;
 
 out_put_sb_page:
@@ -2461,7 +2564,7 @@ out_free_path:
 out_module_put:
 	module_put(THIS_MODULE);
 out:
-	pr_info("error %s: %s", path?path:"", err);
+	pr_info("error %s: %s\n", path?path:"", err);
 	return ret;
 }
 
@@ -2506,7 +2609,7 @@ static ssize_t bch_pending_bdevs_cleanup(struct kobject *k,
 	mutex_unlock(&bch_register_lock);
 
 	list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) {
-		pr_info("delete pdev %p", pdev);
+		pr_info("delete pdev %p\n", pdev);
 		list_del(&pdev->list);
 		bcache_device_stop(&pdev->dc->disk);
 		kfree(pdev);
@@ -2549,7 +2652,7 @@ static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
 
 		mutex_unlock(&bch_register_lock);
 
-		pr_info("Stopping all devices:");
+		pr_info("Stopping all devices:\n");
 
 		/*
 		 * The reason bch_register_lock is not held to call
@@ -2599,9 +2702,9 @@ static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
 		finish_wait(&unregister_wait, &wait);
 
 		if (stopped)
-			pr_info("All devices stopped");
+			pr_info("All devices stopped\n");
 		else
-			pr_notice("Timeout waiting for devices to be closed");
+			pr_notice("Timeout waiting for devices to be closed\n");
 out:
 		mutex_unlock(&bch_register_lock);
 	}
@@ -2637,7 +2740,7 @@ static void check_module_parameters(void)
 	if (bch_cutoff_writeback_sync == 0)
 		bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC;
 	else if (bch_cutoff_writeback_sync > CUTOFF_WRITEBACK_SYNC_MAX) {
-		pr_warn("set bch_cutoff_writeback_sync (%u) to max value %u",
+		pr_warn("set bch_cutoff_writeback_sync (%u) to max value %u\n",
 			bch_cutoff_writeback_sync, CUTOFF_WRITEBACK_SYNC_MAX);
 		bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC_MAX;
 	}
@@ -2645,13 +2748,13 @@ static void check_module_parameters(void)
 	if (bch_cutoff_writeback == 0)
 		bch_cutoff_writeback = CUTOFF_WRITEBACK;
 	else if (bch_cutoff_writeback > CUTOFF_WRITEBACK_MAX) {
-		pr_warn("set bch_cutoff_writeback (%u) to max value %u",
+		pr_warn("set bch_cutoff_writeback (%u) to max value %u\n",
 			bch_cutoff_writeback, CUTOFF_WRITEBACK_MAX);
 		bch_cutoff_writeback = CUTOFF_WRITEBACK_MAX;
 	}
 
 	if (bch_cutoff_writeback > bch_cutoff_writeback_sync) {
-		pr_warn("set bch_cutoff_writeback (%u) to %u",
+		pr_warn("set bch_cutoff_writeback (%u) to %u\n",
 			bch_cutoff_writeback, bch_cutoff_writeback_sync);
 		bch_cutoff_writeback = bch_cutoff_writeback_sync;
 	}
@@ -2662,6 +2765,9 @@ static int __init bcache_init(void)
 	static const struct attribute *files[] = {
 		&ksysfs_register.attr,
 		&ksysfs_register_quiet.attr,
+#ifdef CONFIG_BCACHE_ASYNC_REGISTRAION
+		&ksysfs_register_async.attr,
+#endif
 		&ksysfs_pendings_cleanup.attr,
 		NULL
 	};
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 323276994aab..0dadec5a78f6 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -421,7 +421,7 @@ STORE(__cached_dev)
 				return size;
 		}
 		if (v == -ENOENT)
-			pr_err("Can't attach %s: cache set not found", buf);
+			pr_err("Can't attach %s: cache set not found\n", buf);
 		return v;
 	}
 
@@ -455,7 +455,7 @@ STORE(bch_cached_dev)
 			 */
 			if (dc->writeback_running) {
 				dc->writeback_running = false;
-				pr_err("%s: failed to run non-existent writeback thread",
+				pr_err("%s: failed to run non-existent writeback thread\n",
 						dc->disk.disk->disk_name);
 			}
 		} else
@@ -872,11 +872,11 @@ STORE(__bch_cache_set)
 		if (v) {
 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
 					     &c->flags))
-				pr_warn("CACHE_SET_IO_DISABLE already set");
+				pr_warn("CACHE_SET_IO_DISABLE already set\n");
 		} else {
 			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
 						&c->flags))
-				pr_warn("CACHE_SET_IO_DISABLE already cleared");
+				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
 		}
 	}
 
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 3f7641fb28d5..1cf1e5016cb9 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -809,7 +809,7 @@ static int bch_root_node_dirty_init(struct cache_set *c,
 			schedule_timeout_interruptible(
 				msecs_to_jiffies(INIT_KEYS_SLEEP_MS));
 		else if (ret < 0) {
-			pr_warn("sectors dirty init failed, ret=%d!", ret);
+			pr_warn("sectors dirty init failed, ret=%d!\n", ret);
 			break;
 		}
 	} while (ret == -EAGAIN);
@@ -917,7 +917,7 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 
 	state = kzalloc(sizeof(struct bch_dirty_init_state), GFP_KERNEL);
 	if (!state) {
-		pr_warn("sectors dirty init failed: cannot allocate memory");
+		pr_warn("sectors dirty init failed: cannot allocate memory\n");
 		return;
 	}
 
@@ -945,7 +945,7 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 				    &state->infos[i],
 				    name);
 		if (IS_ERR(state->infos[i].thread)) {
-			pr_err("fails to run thread bch_dirty_init[%d]", i);
+			pr_err("fails to run thread bch_dirty_init[%d]\n", i);
 			for (--i; i >= 0; i--)
 				kthread_stop(state->infos[i].thread);
 			goto out;
diff --git a/drivers/md/md-linear.h b/drivers/md/md-linear.h
index 8381d651d4ed..24e97db50ebb 100644
--- a/drivers/md/md-linear.h
+++ b/drivers/md/md-linear.h
@@ -12,6 +12,6 @@ struct linear_conf
 	struct rcu_head		rcu;
 	sector_t		array_sectors;
 	int			raid_disks; /* a copy of mddev->raid_disks */
-	struct dev_info		disks[0];
+	struct dev_info		disks[];
 };
 #endif
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 271e8a587354..f567f536b529 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -89,6 +89,7 @@ static struct module *md_cluster_mod;
 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 static struct workqueue_struct *md_wq;
 static struct workqueue_struct *md_misc_wq;
+static struct workqueue_struct *md_rdev_misc_wq;
 
 static int remove_and_add_spares(struct mddev *mddev,
 				 struct md_rdev *this);
@@ -227,13 +228,13 @@ void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
 		goto abort;
 
 	if (mddev->serial_info_pool == NULL) {
-		unsigned int noio_flag;
-
-		noio_flag = memalloc_noio_save();
+		/*
+		 * already in memalloc noio context by
+		 * mddev_suspend()
+		 */
 		mddev->serial_info_pool =
 			mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
 						sizeof(struct serial_info));
-		memalloc_noio_restore(noio_flag);
 		if (!mddev->serial_info_pool) {
 			rdevs_uninit_serial(mddev);
 			pr_err("can't alloc memory pool for serialization\n");
@@ -466,7 +467,7 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 {
 	const int rw = bio_data_dir(bio);
 	const int sgrp = op_stat_group(bio_op(bio));
-	struct mddev *mddev = q->queuedata;
+	struct mddev *mddev = bio->bi_disk->private_data;
 	unsigned int sectors;
 
 	if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) {
@@ -527,11 +528,15 @@ void mddev_suspend(struct mddev *mddev)
 	wait_event(mddev->sb_wait, !test_bit(MD_UPDATING_SB, &mddev->flags));
 
 	del_timer_sync(&mddev->safemode_timer);
+	/* restrict memory reclaim I/O during raid array is suspend */
+	mddev->noio_flag = memalloc_noio_save();
 }
 EXPORT_SYMBOL_GPL(mddev_suspend);
 
 void mddev_resume(struct mddev *mddev)
 {
+	/* entred the memalloc scope from mddev_suspend() */
+	memalloc_noio_restore(mddev->noio_flag);
 	lockdep_assert_held(&mddev->reconfig_mutex);
 	if (--mddev->suspended)
 		return;
@@ -2454,7 +2459,7 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
 	return err;
 }
 
-static void md_delayed_delete(struct work_struct *ws)
+static void rdev_delayed_delete(struct work_struct *ws)
 {
 	struct md_rdev *rdev = container_of(ws, struct md_rdev, del_work);
 	kobject_del(&rdev->kobj);
@@ -2479,9 +2484,9 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
 	 * to delay it due to rcu usage.
 	 */
 	synchronize_rcu();
-	INIT_WORK(&rdev->del_work, md_delayed_delete);
+	INIT_WORK(&rdev->del_work, rdev_delayed_delete);
 	kobject_get(&rdev->kobj);
-	queue_work(md_misc_wq, &rdev->del_work);
+	queue_work(md_rdev_misc_wq, &rdev->del_work);
 }
 
 /*
@@ -3191,8 +3196,7 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
 			rdev->saved_raid_disk = -1;
 		clear_bit(In_sync, &rdev->flags);
 		clear_bit(Bitmap_sync, &rdev->flags);
-		err = rdev->mddev->pers->
-			hot_add_disk(rdev->mddev, rdev);
+		err = rdev->mddev->pers->hot_add_disk(rdev->mddev, rdev);
 		if (err) {
 			rdev->raid_disk = -1;
 			return err;
@@ -4514,6 +4518,20 @@ null_show(struct mddev *mddev, char *page)
 	return -EINVAL;
 }
 
+/* need to ensure rdev_delayed_delete() has completed */
+static void flush_rdev_wq(struct mddev *mddev)
+{
+	struct md_rdev *rdev;
+
+	rcu_read_lock();
+	rdev_for_each_rcu(rdev, mddev)
+		if (work_pending(&rdev->del_work)) {
+			flush_workqueue(md_rdev_misc_wq);
+			break;
+		}
+	rcu_read_unlock();
+}
+
 static ssize_t
 new_dev_store(struct mddev *mddev, const char *buf, size_t len)
 {
@@ -4541,8 +4559,7 @@ new_dev_store(struct mddev *mddev, const char *buf, size_t len)
 	    minor != MINOR(dev))
 		return -EOVERFLOW;
 
-	flush_workqueue(md_misc_wq);
-
+	flush_rdev_wq(mddev);
 	err = mddev_lock(mddev);
 	if (err)
 		return err;
@@ -4780,7 +4797,8 @@ action_store(struct mddev *mddev, const char *page, size_t len)
 			clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
 		    mddev_lock(mddev) == 0) {
-			flush_workqueue(md_misc_wq);
+			if (work_pending(&mddev->del_work))
+				flush_workqueue(md_misc_wq);
 			if (mddev->sync_thread) {
 				set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 				md_reap_sync_thread(mddev);
@@ -5626,7 +5644,6 @@ static int md_alloc(dev_t dev, char *name)
 	mddev->queue = blk_alloc_queue(md_make_request, NUMA_NO_NODE);
 	if (!mddev->queue)
 		goto abort;
-	mddev->queue->queuedata = mddev;
 
 	blk_set_stacking_limits(&mddev->queue->limits);
 
@@ -6147,7 +6164,8 @@ static void md_clean(struct mddev *mddev)
 static void __md_stop_writes(struct mddev *mddev)
 {
 	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-	flush_workqueue(md_misc_wq);
+	if (work_pending(&mddev->del_work))
+		flush_workqueue(md_misc_wq);
 	if (mddev->sync_thread) {
 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 		md_reap_sync_thread(mddev);
@@ -6200,7 +6218,8 @@ static void __md_stop(struct mddev *mddev)
 	md_bitmap_destroy(mddev);
 	mddev_detach(mddev);
 	/* Ensure ->event_work is done */
-	flush_workqueue(md_misc_wq);
+	if (mddev->event_work.func)
+		flush_workqueue(md_misc_wq);
 	spin_lock(&mddev->lock);
 	mddev->pers = NULL;
 	spin_unlock(&mddev->lock);
@@ -7495,9 +7514,8 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 
 	}
 
-	if (cmd == ADD_NEW_DISK)
-		/* need to ensure md_delayed_delete() has completed */
-		flush_workqueue(md_misc_wq);
+	if (cmd == ADD_NEW_DISK || cmd == HOT_ADD_DISK)
+		flush_rdev_wq(mddev);
 
 	if (cmd == HOT_REMOVE_DISK)
 		/* need to ensure recovery thread has run */
@@ -7752,7 +7770,8 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 		 */
 		mddev_put(mddev);
 		/* Wait until bdev->bd_disk is definitely gone */
-		flush_workqueue(md_misc_wq);
+		if (work_pending(&mddev->del_work))
+			flush_workqueue(md_misc_wq);
 		/* Then retry the open from the top */
 		return -ERESTARTSYS;
 	}
@@ -9040,8 +9059,7 @@ static int remove_and_add_spares(struct mddev *mddev,
 
 			rdev->recovery_offset = 0;
 		}
-		if (mddev->pers->
-		    hot_add_disk(mddev, rdev) == 0) {
+		if (mddev->pers->hot_add_disk(mddev, rdev) == 0) {
 			if (sysfs_link_rdev(mddev, rdev))
 				/* failure here is OK */;
 			if (!test_bit(Journal, &rdev->flags))
@@ -9469,6 +9487,10 @@ static int __init md_init(void)
 	if (!md_misc_wq)
 		goto err_misc_wq;
 
+	md_rdev_misc_wq = alloc_workqueue("md_rdev_misc", 0, 0);
+	if (!md_misc_wq)
+		goto err_rdev_misc_wq;
+
 	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
 		goto err_md;
 
@@ -9490,6 +9512,8 @@ static int __init md_init(void)
 err_mdp:
 	unregister_blkdev(MD_MAJOR, "md");
 err_md:
+	destroy_workqueue(md_rdev_misc_wq);
+err_rdev_misc_wq:
 	destroy_workqueue(md_misc_wq);
 err_misc_wq:
 	destroy_workqueue(md_wq);
@@ -9776,6 +9800,7 @@ static __exit void md_exit(void)
 		 * destroy_workqueue() below will wait for that to complete.
 		 */
 	}
+	destroy_workqueue(md_rdev_misc_wq);
 	destroy_workqueue(md_misc_wq);
 	destroy_workqueue(md_wq);
 }
@@ -9785,7 +9810,7 @@ module_exit(md_exit)
 
 static int get_ro(char *buffer, const struct kernel_param *kp)
 {
-	return sprintf(buffer, "%d", start_readonly);
+	return sprintf(buffer, "%d\n", start_readonly);
 }
 static int set_ro(const char *val, const struct kernel_param *kp)
 {
diff --git a/drivers/md/md.h b/drivers/md/md.h
index acd681939112..612814d07d35 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -497,6 +497,7 @@ struct mddev {
 	void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
 	struct md_cluster_info		*cluster_info;
 	unsigned int			good_device_nr;	/* good device num within cluster raid */
+	unsigned int			noio_flag; /* for memalloc scope API */
 
 	bool	has_superblocks:1;
 	bool	fail_last_dev:1;
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index cd810e195086..dcd27f3da84e 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -296,22 +296,17 @@ static void reschedule_retry(struct r1bio *r1_bio)
 static void call_bio_endio(struct r1bio *r1_bio)
 {
 	struct bio *bio = r1_bio->master_bio;
-	struct r1conf *conf = r1_bio->mddev->private;
 
 	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
 		bio->bi_status = BLK_STS_IOERR;
 
 	bio_endio(bio);
-	/*
-	 * Wake up any possible resync thread that waits for the device
-	 * to go idle.
-	 */
-	allow_barrier(conf, r1_bio->sector);
 }
 
 static void raid_end_bio_io(struct r1bio *r1_bio)
 {
 	struct bio *bio = r1_bio->master_bio;
+	struct r1conf *conf = r1_bio->mddev->private;
 
 	/* if nobody has done the final endio yet, do it now */
 	if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
@@ -322,6 +317,12 @@ static void raid_end_bio_io(struct r1bio *r1_bio)
 
 		call_bio_endio(r1_bio);
 	}
+	/*
+	 * Wake up any possible resync thread that waits for the device
+	 * to go idle.  All I/Os, even write-behind writes, are done.
+	 */
+	allow_barrier(conf, r1_bio->sector);
+
 	free_r1bio(r1_bio);
 }
 
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index e7ccad898736..b7eb09e8c025 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -180,7 +180,7 @@ struct r1bio {
 	 * if the IO is in WRITE direction, then multiple bios are used.
 	 * We choose the number when they are allocated.
 	 */
-	struct bio		*bios[0];
+	struct bio		*bios[];
 	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 };
 
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index d3eaaf3eb1bc..79cd2b7d3128 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -153,7 +153,7 @@ struct r10bio {
 		};
 		sector_t	addr;
 		int		devnum;
-	} devs[0];
+	} devs[];
 };
 
 /* bits for r10bio.state */
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ba00e9877f02..ab8067f9ce8c 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2215,10 +2215,13 @@ static int grow_stripes(struct r5conf *conf, int num)
 }
 
 /**
- * scribble_len - return the required size of the scribble region
+ * scribble_alloc - allocate percpu scribble buffer for required size
+ *		    of the scribble region
+ * @percpu - from for_each_present_cpu() of the caller
  * @num - total number of disks in the array
+ * @cnt - scribble objs count for required size of the scribble region
  *
- * The size must be enough to contain:
+ * The scribble buffer size must be enough to contain:
  * 1/ a struct page pointer for each device in the array +2
  * 2/ room to convert each entry in (1) to its corresponding dma
  *    (dma_map_page()) or page (page_address()) address.
@@ -2228,14 +2231,19 @@ static int grow_stripes(struct r5conf *conf, int num)
  * of the P and Q blocks.
  */
 static int scribble_alloc(struct raid5_percpu *percpu,
-			  int num, int cnt, gfp_t flags)
+			  int num, int cnt)
 {
 	size_t obj_size =
 		sizeof(struct page *) * (num+2) +
 		sizeof(addr_conv_t) * (num+2);
 	void *scribble;
 
-	scribble = kvmalloc_array(cnt, obj_size, flags);
+	/*
+	 * If here is in raid array suspend context, it is in memalloc noio
+	 * context as well, there is no potential recursive memory reclaim
+	 * I/Os with the GFP_KERNEL flag.
+	 */
+	scribble = kvmalloc_array(cnt, obj_size, GFP_KERNEL);
 	if (!scribble)
 		return -ENOMEM;
 
@@ -2267,8 +2275,7 @@ static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
 
 		percpu = per_cpu_ptr(conf->percpu, cpu);
 		err = scribble_alloc(percpu, new_disks,
-				     new_sectors / STRIPE_SECTORS,
-				     GFP_NOIO);
+				     new_sectors / STRIPE_SECTORS);
 		if (err)
 			break;
 	}
@@ -6759,8 +6766,7 @@ static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu
 			       conf->previous_raid_disks),
 			   max(conf->chunk_sectors,
 			       conf->prev_chunk_sectors)
-			   / STRIPE_SECTORS,
-			   GFP_KERNEL)) {
+			   / STRIPE_SECTORS)) {
 		free_scratch_buffer(conf, percpu);
 		return -ENOMEM;
 	}