Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "I've got a few bits pending for 3.8 final, that I better get sent out.
  It's all been sitting for a while, I consider it safe.

  It contains:

   - Two bug fixes for mtip32xx, fixing a driver hang and a crash.

   - A few-liner protocol error fix for drbd.

   - A few fixes for the xen block front/back driver, fixing a potential
     data corruption issue.

   - A race fix for disk_clear_events(), causing spurious warnings.  Out
     of the Chrome OS base.

   - A deadlock fix for disk_clear_events(), moving it to the a
     unfreezable workqueue.  Also from the Chrome OS base."

* 'for-linus' of git://git.kernel.dk/linux-block:
  drbd: fix potential protocol error and resulting disconnect/reconnect
  mtip32xx: fix for crash when the device surprise removed during rebuild
  mtip32xx: fix for driver hang after a command timeout
  block: prevent race/cleanup
  block: remove deadlock in disk_clear_events
  xen-blkfront: handle bvecs with partial data
  llist/xen-blkfront: implement safe version of llist_for_each_entry
  xen-blkback: implement safe iterator for the list of persistent grants

6 files changed, 44 insertions, 18 deletions

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index f58a4a4b4dfb..2b8303ad63c9 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -168,7 +168,7 @@ static void wake_all_senders(struct drbd_tconn *tconn) {
 }
 
 /* must hold resource->req_lock */
-static void start_new_tl_epoch(struct drbd_tconn *tconn)
+void start_new_tl_epoch(struct drbd_tconn *tconn)
 {
 	/* no point closing an epoch, if it is empty, anyways. */
 	if (tconn->current_tle_writes == 0)
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 016de6b8bb57..c08d22964d06 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -267,6 +267,7 @@ struct bio_and_error {
 	int error;
 };
 
+extern void start_new_tl_epoch(struct drbd_tconn *tconn);
 extern void drbd_req_destroy(struct kref *kref);
 extern void _req_may_be_done(struct drbd_request *req,
 		struct bio_and_error *m);
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 53bf6182bac4..0fe220cfb9e9 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -931,6 +931,7 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
 	enum drbd_state_rv rv = SS_SUCCESS;
 	enum sanitize_state_warnings ssw;
 	struct after_state_chg_work *ascw;
+	bool did_remote, should_do_remote;
 
 	os = drbd_read_state(mdev);
 
@@ -981,11 +982,17 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
 	    (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
 		atomic_inc(&mdev->local_cnt);
 
+	did_remote = drbd_should_do_remote(mdev->state);
 	mdev->state.i = ns.i;
+	should_do_remote = drbd_should_do_remote(mdev->state);
 	mdev->tconn->susp = ns.susp;
 	mdev->tconn->susp_nod = ns.susp_nod;
 	mdev->tconn->susp_fen = ns.susp_fen;
 
+	/* put replicated vs not-replicated requests in seperate epochs */
+	if (did_remote != should_do_remote)
+		start_new_tl_epoch(mdev->tconn);
+
 	if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
 		drbd_print_uuids(mdev, "attached to UUIDs");
 
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 9694dd99bbbc..3fd100990453 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -626,12 +626,13 @@ static void mtip_timeout_function(unsigned long int data)
 		}
 	}
 
-	if (cmdto_cnt && !test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+	if (cmdto_cnt) {
 		print_tags(port->dd, "timed out", tagaccum, cmdto_cnt);
-
-		mtip_restart_port(port);
+		if (!test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+			mtip_restart_port(port);
+			wake_up_interruptible(&port->svc_wait);
+		}
 		clear_bit(MTIP_PF_EH_ACTIVE_BIT, &port->flags);
-		wake_up_interruptible(&port->svc_wait);
 	}
 
 	if (port->ic_pause_timer) {
@@ -3887,7 +3888,12 @@ static int mtip_block_remove(struct driver_data *dd)
 	 * Delete our gendisk structure. This also removes the device
 	 * from /dev
 	 */
-	del_gendisk(dd->disk);
+	if (dd->disk) {
+		if (dd->disk->queue)
+			del_gendisk(dd->disk);
+		else
+			put_disk(dd->disk);
+	}
 
 	spin_lock(&rssd_index_lock);
 	ida_remove(&rssd_index_ida, dd->index);
@@ -3921,7 +3927,13 @@ static int mtip_block_shutdown(struct driver_data *dd)
 		"Shutting down %s ...\n", dd->disk->disk_name);
 
 	/* Delete our gendisk structure, and cleanup the blk queue. */
-	del_gendisk(dd->disk);
+	if (dd->disk) {
+		if (dd->disk->queue)
+			del_gendisk(dd->disk);
+		else
+			put_disk(dd->disk);
+	}
+
 
 	spin_lock(&rssd_index_lock);
 	ida_remove(&rssd_index_ida, dd->index);
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 74374fb762aa..5ac841ff6cc7 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -161,10 +161,12 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 static void make_response(struct xen_blkif *blkif, u64 id,
 			  unsigned short op, int st);
 
-#define foreach_grant(pos, rbtree, node) \
-	for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node); \
+#define foreach_grant_safe(pos, n, rbtree, node) \
+	for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \
+	     (n) = rb_next(&(pos)->node); \
 	     &(pos)->node != NULL; \
-	     (pos) = container_of(rb_next(&(pos)->node), typeof(*(pos)), node))
+	     (pos) = container_of(n, typeof(*(pos)), node), \
+	     (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL)
 
 
 static void add_persistent_gnt(struct rb_root *root,
@@ -217,10 +219,11 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
 	struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 	struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 	struct persistent_gnt *persistent_gnt;
+	struct rb_node *n;
 	int ret = 0;
 	int segs_to_unmap = 0;
 
-	foreach_grant(persistent_gnt, root, node) {
+	foreach_grant_safe(persistent_gnt, n, root, node) {
 		BUG_ON(persistent_gnt->handle ==
 			BLKBACK_INVALID_HANDLE);
 		gnttab_set_unmap_op(&unmap[segs_to_unmap],
@@ -230,9 +233,6 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
 			persistent_gnt->handle);
 
 		pages[segs_to_unmap] = persistent_gnt->page;
-		rb_erase(&persistent_gnt->node, root);
-		kfree(persistent_gnt);
-		num--;
 
 		if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
 			!rb_next(&persistent_gnt->node)) {
@@ -241,6 +241,10 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
 			BUG_ON(ret);
 			segs_to_unmap = 0;
 		}
+
+		rb_erase(&persistent_gnt->node, root);
+		kfree(persistent_gnt);
+		num--;
 	}
 	BUG_ON(num != 0);
 }
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 96e9b00db081..11043c18ac5a 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -792,6 +792,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 {
 	struct llist_node *all_gnts;
 	struct grant *persistent_gnt;
+	struct llist_node *n;
 
 	/* Prevent new requests being issued until we fix things up. */
 	spin_lock_irq(&info->io_lock);
@@ -804,7 +805,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 	/* Remove all persistent grants */
 	if (info->persistent_gnts_c) {
 		all_gnts = llist_del_all(&info->persistent_gnts);
-		llist_for_each_entry(persistent_gnt, all_gnts, node) {
+		llist_for_each_entry_safe(persistent_gnt, n, all_gnts, node) {
 			gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
 			__free_page(pfn_to_page(persistent_gnt->pfn));
 			kfree(persistent_gnt);
@@ -835,7 +836,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 			     struct blkif_response *bret)
 {
-	int i;
+	int i = 0;
 	struct bio_vec *bvec;
 	struct req_iterator iter;
 	unsigned long flags;
@@ -852,7 +853,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 		 */
 		rq_for_each_segment(bvec, s->request, iter) {
 			BUG_ON((bvec->bv_offset + bvec->bv_len) > PAGE_SIZE);
-			i = offset >> PAGE_SHIFT;
+			if (bvec->bv_offset < offset)
+				i++;
 			BUG_ON(i >= s->req.u.rw.nr_segments);
 			shared_data = kmap_atomic(
 				pfn_to_page(s->grants_used[i]->pfn));
@@ -861,7 +863,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 				bvec->bv_len);
 			bvec_kunmap_irq(bvec_data, &flags);
 			kunmap_atomic(shared_data);
-			offset += bvec->bv_len;
+			offset = bvec->bv_offset + bvec->bv_len;
 		}
 	}
 	/* Add the persistent grant into the list of free grants */