Merge tag 'for-5.3/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Revert a DM bufio change from during the 5.3 merge window now that a
   proper fix has been made to the block loopback driver.

 - Fix DM kcopyd to wakeup so failed subjobs get completed.

 - Various fixes to DM zoned target to address error handling, and other
   small tweaks (SPDX license identifiers and fix typos).

 - Fix DM integrity range locking race by tracking whether journal has
   changed.

 - Fix DM dust target to detect reads of badblocks beyond the first 512b
   sector (applicable if blocksize is larger than 512b).

 - Fix DM persistent-data issue in both the DM btree and DM
   space-map-metadata interfaces.

 - Fix out of bounds memory access with certain DM table configurations.

* tag 'for-5.3/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm table: fix invalid memory accesses with too high sector number
  dm space map metadata: fix missing store of apply_bops() return value
  dm btree: fix order of block initialization in btree_split_beneath
  dm raid: add missing cleanup in raid_ctr()
  dm zoned: fix potential NULL dereference in dmz_do_reclaim()
  dm dust: use dust block size for badblocklist index
  dm integrity: fix a crash due to BUG_ON in __journal_read_write()
  dm zoned: fix a few typos
  dm zoned: add SPDX license identifiers
  dm zoned: properly handle backing device failure
  dm zoned: improve error handling in i/o map code
  dm zoned: improve error handling in reclaim
  dm kcopyd: always complete failed jobs
  Revert "dm bufio: fix deadlock with loop device"

12 files changed, 209 insertions, 60 deletions

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index b6b5acc92ca2..2a48ea3f1b30 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1599,7 +1599,9 @@ dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 	unsigned long freed;
 
 	c = container_of(shrink, struct dm_bufio_client, shrinker);
-	if (!dm_bufio_trylock(c))
+	if (sc->gfp_mask & __GFP_FS)
+		dm_bufio_lock(c);
+	else if (!dm_bufio_trylock(c))
 		return SHRINK_STOP;
 
 	freed  = __scan(c, sc->nr_to_scan, sc->gfp_mask);
diff --git a/drivers/md/dm-dust.c b/drivers/md/dm-dust.c
index 845f376a72d9..8288887b7f94 100644
--- a/drivers/md/dm-dust.c
+++ b/drivers/md/dm-dust.c
@@ -25,6 +25,7 @@ struct dust_device {
 	unsigned long long badblock_count;
 	spinlock_t dust_lock;
 	unsigned int blksz;
+	int sect_per_block_shift;
 	unsigned int sect_per_block;
 	sector_t start;
 	bool fail_read_on_bb:1;
@@ -79,7 +80,7 @@ static int dust_remove_block(struct dust_device *dd, unsigned long long block)
 	unsigned long flags;
 
 	spin_lock_irqsave(&dd->dust_lock, flags);
-	bblock = dust_rb_search(&dd->badblocklist, block * dd->sect_per_block);
+	bblock = dust_rb_search(&dd->badblocklist, block);
 
 	if (bblock == NULL) {
 		if (!dd->quiet_mode) {
@@ -113,7 +114,7 @@ static int dust_add_block(struct dust_device *dd, unsigned long long block)
 	}
 
 	spin_lock_irqsave(&dd->dust_lock, flags);
-	bblock->bb = block * dd->sect_per_block;
+	bblock->bb = block;
 	if (!dust_rb_insert(&dd->badblocklist, bblock)) {
 		if (!dd->quiet_mode) {
 			DMERR("%s: block %llu already in badblocklist",
@@ -138,7 +139,7 @@ static int dust_query_block(struct dust_device *dd, unsigned long long block)
 	unsigned long flags;
 
 	spin_lock_irqsave(&dd->dust_lock, flags);
-	bblock = dust_rb_search(&dd->badblocklist, block * dd->sect_per_block);
+	bblock = dust_rb_search(&dd->badblocklist, block);
 	if (bblock != NULL)
 		DMINFO("%s: block %llu found in badblocklist", __func__, block);
 	else
@@ -165,6 +166,7 @@ static int dust_map_read(struct dust_device *dd, sector_t thisblock,
 	int ret = DM_MAPIO_REMAPPED;
 
 	if (fail_read_on_bb) {
+		thisblock >>= dd->sect_per_block_shift;
 		spin_lock_irqsave(&dd->dust_lock, flags);
 		ret = __dust_map_read(dd, thisblock);
 		spin_unlock_irqrestore(&dd->dust_lock, flags);
@@ -195,6 +197,7 @@ static int dust_map_write(struct dust_device *dd, sector_t thisblock,
 	unsigned long flags;
 
 	if (fail_read_on_bb) {
+		thisblock >>= dd->sect_per_block_shift;
 		spin_lock_irqsave(&dd->dust_lock, flags);
 		__dust_map_write(dd, thisblock);
 		spin_unlock_irqrestore(&dd->dust_lock, flags);
@@ -331,6 +334,8 @@ static int dust_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	dd->blksz = blksz;
 	dd->start = tmp;
 
+	dd->sect_per_block_shift = __ffs(sect_per_block);
+
 	/*
 	 * Whether to fail a read on a "bad" block.
 	 * Defaults to false; enabled later by message.
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index b1b0de402dfc..9118ab85cb3a 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1943,7 +1943,22 @@ offload_to_thread:
 			queue_work(ic->wait_wq, &dio->work);
 			return;
 		}
+		if (journal_read_pos != NOT_FOUND)
+			dio->range.n_sectors = ic->sectors_per_block;
 		wait_and_add_new_range(ic, &dio->range);
+		/*
+		 * wait_and_add_new_range drops the spinlock, so the journal
+		 * may have been changed arbitrarily. We need to recheck.
+		 * To simplify the code, we restrict I/O size to just one block.
+		 */
+		if (journal_read_pos != NOT_FOUND) {
+			sector_t next_sector;
+			unsigned new_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
+			if (unlikely(new_pos != journal_read_pos)) {
+				remove_range_unlocked(ic, &dio->range);
+				goto retry;
+			}
+		}
 	}
 	spin_unlock_irq(&ic->endio_wait.lock);
 
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index df2011de7be2..1bbe4a34ef4c 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -566,8 +566,10 @@ static int run_io_job(struct kcopyd_job *job)
 	 * no point in continuing.
 	 */
 	if (test_bit(DM_KCOPYD_WRITE_SEQ, &job->flags) &&
-	    job->master_job->write_err)
+	    job->master_job->write_err) {
+		job->write_err = job->master_job->write_err;
 		return -EIO;
+	}
 
 	io_job_start(job->kc->throttle);
 
@@ -619,6 +621,7 @@ static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc,
 			else
 				job->read_err = 1;
 			push(&kc->complete_jobs, job);
+			wake(kc);
 			break;
 		}
 
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 8a60a4a070ac..1f933dd197cd 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3194,7 +3194,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 			  */
 			r = rs_prepare_reshape(rs);
 			if (r)
-				return r;
+				goto bad;
 
 			/* Reshaping ain't recovery, so disable recovery */
 			rs_setup_recovery(rs, MaxSector);
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 7b6c3ee9e755..8820931ec7d2 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1342,7 +1342,7 @@ void dm_table_event(struct dm_table *t)
 }
 EXPORT_SYMBOL(dm_table_event);
 
-sector_t dm_table_get_size(struct dm_table *t)
+inline sector_t dm_table_get_size(struct dm_table *t)
 {
 	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
 }
@@ -1367,6 +1367,9 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 	unsigned int l, n = 0, k = 0;
 	sector_t *node;
 
+	if (unlikely(sector >= dm_table_get_size(t)))
+		return &t->targets[t->num_targets];
+
 	for (l = 0; l < t->depth; l++) {
 		n = get_child(n, k);
 		node = get_node(t, l, n);
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 8545dcee9fd0..595a73110e17 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
  *
@@ -34,7 +35,7 @@
  *    (1) Super block (1 block)
  *    (2) Chunk mapping table (nr_map_blocks)
  *    (3) Bitmap blocks (nr_bitmap_blocks)
- * All metadata blocks are stored in conventional zones, starting from the
+ * All metadata blocks are stored in conventional zones, starting from
  * the first conventional zone found on disk.
  */
 struct dmz_super {
@@ -233,7 +234,7 @@ void dmz_unlock_map(struct dmz_metadata *zmd)
  * Lock/unlock metadata access. This is a "read" lock on a semaphore
  * that prevents metadata flush from running while metadata are being
  * modified. The actual metadata write mutual exclusion is achieved with
- * the map lock and zone styate management (active and reclaim state are
+ * the map lock and zone state management (active and reclaim state are
  * mutually exclusive).
  */
 void dmz_lock_metadata(struct dmz_metadata *zmd)
@@ -402,15 +403,18 @@ static struct dmz_mblock *dmz_get_mblock_slow(struct dmz_metadata *zmd,
 	sector_t block = zmd->sb[zmd->mblk_primary].block + mblk_no;
 	struct bio *bio;
 
+	if (dmz_bdev_is_dying(zmd->dev))
+		return ERR_PTR(-EIO);
+
 	/* Get a new block and a BIO to read it */
 	mblk = dmz_alloc_mblock(zmd, mblk_no);
 	if (!mblk)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	bio = bio_alloc(GFP_NOIO, 1);
 	if (!bio) {
 		dmz_free_mblock(zmd, mblk);
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	spin_lock(&zmd->mblk_lock);
@@ -541,8 +545,8 @@ static struct dmz_mblock *dmz_get_mblock(struct dmz_metadata *zmd,
 	if (!mblk) {
 		/* Cache miss: read the block from disk */
 		mblk = dmz_get_mblock_slow(zmd, mblk_no);
-		if (!mblk)
-			return ERR_PTR(-ENOMEM);
+		if (IS_ERR(mblk))
+			return mblk;
 	}
 
 	/* Wait for on-going read I/O and check for error */
@@ -570,16 +574,19 @@ static void dmz_dirty_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
 /*
  * Issue a metadata block write BIO.
  */
-static void dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
-			     unsigned int set)
+static int dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
+			    unsigned int set)
 {
 	sector_t block = zmd->sb[set].block + mblk->no;
 	struct bio *bio;
 
+	if (dmz_bdev_is_dying(zmd->dev))
+		return -EIO;
+
 	bio = bio_alloc(GFP_NOIO, 1);
 	if (!bio) {
 		set_bit(DMZ_META_ERROR, &mblk->state);
-		return;
+		return -ENOMEM;
 	}
 
 	set_bit(DMZ_META_WRITING, &mblk->state);
@@ -591,6 +598,8 @@ static void dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
 	bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_META | REQ_PRIO);
 	bio_add_page(bio, mblk->page, DMZ_BLOCK_SIZE, 0);
 	submit_bio(bio);
+
+	return 0;
 }
 
 /*
@@ -602,6 +611,9 @@ static int dmz_rdwr_block(struct dmz_metadata *zmd, int op, sector_t block,
 	struct bio *bio;
 	int ret;
 
+	if (dmz_bdev_is_dying(zmd->dev))
+		return -EIO;
+
 	bio = bio_alloc(GFP_NOIO, 1);
 	if (!bio)
 		return -ENOMEM;
@@ -659,22 +671,29 @@ static int dmz_write_dirty_mblocks(struct dmz_metadata *zmd,
 {
 	struct dmz_mblock *mblk;
 	struct blk_plug plug;
-	int ret = 0;
+	int ret = 0, nr_mblks_submitted = 0;
 
 	/* Issue writes */
 	blk_start_plug(&plug);
-	list_for_each_entry(mblk, write_list, link)
-		dmz_write_mblock(zmd, mblk, set);
+	list_for_each_entry(mblk, write_list, link) {
+		ret = dmz_write_mblock(zmd, mblk, set);
+		if (ret)
+			break;
+		nr_mblks_submitted++;
+	}
 	blk_finish_plug(&plug);
 
 	/* Wait for completion */
 	list_for_each_entry(mblk, write_list, link) {
+		if (!nr_mblks_submitted)
+			break;
 		wait_on_bit_io(&mblk->state, DMZ_META_WRITING,
 			       TASK_UNINTERRUPTIBLE);
 		if (test_bit(DMZ_META_ERROR, &mblk->state)) {
 			clear_bit(DMZ_META_ERROR, &mblk->state);
 			ret = -EIO;
 		}
+		nr_mblks_submitted--;
 	}
 
 	/* Flush drive cache (this will also sync data) */
@@ -736,6 +755,11 @@ int dmz_flush_metadata(struct dmz_metadata *zmd)
 	 */
 	dmz_lock_flush(zmd);
 
+	if (dmz_bdev_is_dying(zmd->dev)) {
+		ret = -EIO;
+		goto out;
+	}
+
 	/* Get dirty blocks */
 	spin_lock(&zmd->mblk_lock);
 	list_splice_init(&zmd->mblk_dirty_list, &write_list);
@@ -1542,7 +1566,7 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd)
 	struct dm_zone *zone;
 
 	if (list_empty(&zmd->map_rnd_list))
-		return NULL;
+		return ERR_PTR(-EBUSY);
 
 	list_for_each_entry(zone, &zmd->map_rnd_list, link) {
 		if (dmz_is_buf(zone))
@@ -1553,7 +1577,7 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd)
 			return dzone;
 	}
 
-	return NULL;
+	return ERR_PTR(-EBUSY);
 }
 
 /*
@@ -1564,7 +1588,7 @@ static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
 	struct dm_zone *zone;
 
 	if (list_empty(&zmd->map_seq_list))
-		return NULL;
+		return ERR_PTR(-EBUSY);
 
 	list_for_each_entry(zone, &zmd->map_seq_list, link) {
 		if (!zone->bzone)
@@ -1573,7 +1597,7 @@ static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
 			return zone;
 	}
 
-	return NULL;
+	return ERR_PTR(-EBUSY);
 }
 
 /*
@@ -1628,9 +1652,13 @@ again:
 		if (op != REQ_OP_WRITE)
 			goto out;
 
-		/* Alloate a random zone */
+		/* Allocate a random zone */
 		dzone = dmz_alloc_zone(zmd, DMZ_ALLOC_RND);
 		if (!dzone) {
+			if (dmz_bdev_is_dying(zmd->dev)) {
+				dzone = ERR_PTR(-EIO);
+				goto out;
+			}
 			dmz_wait_for_free_zones(zmd);
 			goto again;
 		}
@@ -1725,9 +1753,13 @@ again:
 	if (bzone)
 		goto out;
 
-	/* Alloate a random zone */
+	/* Allocate a random zone */
 	bzone = dmz_alloc_zone(zmd, DMZ_ALLOC_RND);
 	if (!bzone) {
+		if (dmz_bdev_is_dying(zmd->dev)) {
+			bzone = ERR_PTR(-EIO);
+			goto out;
+		}
 		dmz_wait_for_free_zones(zmd);
 		goto again;
 	}
diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
index edf4b95eb075..d240d7ca8a8a 100644
--- a/drivers/md/dm-zoned-reclaim.c
+++ b/drivers/md/dm-zoned-reclaim.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
  *
@@ -37,7 +38,7 @@ enum {
 /*
  * Number of seconds of target BIO inactivity to consider the target idle.
  */
-#define DMZ_IDLE_PERIOD		(10UL * HZ)
+#define DMZ_IDLE_PERIOD			(10UL * HZ)
 
 /*
  * Percentage of unmapped (free) random zones below which reclaim starts
@@ -134,6 +135,9 @@ static int dmz_reclaim_copy(struct dmz_reclaim *zrc,
 		set_bit(DM_KCOPYD_WRITE_SEQ, &flags);
 
 	while (block < end_block) {
+		if (dev->flags & DMZ_BDEV_DYING)
+			return -EIO;
+
 		/* Get a valid region from the source zone */
 		ret = dmz_first_valid_block(zmd, src_zone, &block);
 		if (ret <= 0)
@@ -215,7 +219,7 @@ static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)
 
 	dmz_unlock_flush(zmd);
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -259,7 +263,7 @@ static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
 
 	dmz_unlock_flush(zmd);
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -312,7 +316,7 @@ static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
 
 	dmz_unlock_flush(zmd);
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -334,7 +338,7 @@ static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)
 /*
  * Find a candidate zone for reclaim and process it.
  */
-static void dmz_reclaim(struct dmz_reclaim *zrc)
+static int dmz_do_reclaim(struct dmz_reclaim *zrc)
 {
 	struct dmz_metadata *zmd = zrc->metadata;
 	struct dm_zone *dzone;
@@ -344,8 +348,8 @@ static void dmz_reclaim(struct dmz_reclaim *zrc)
 
 	/* Get a data zone */
 	dzone = dmz_get_zone_for_reclaim(zmd);
-	if (!dzone)
-		return;
+	if (IS_ERR(dzone))
+		return PTR_ERR(dzone);
 
 	start = jiffies;
 
@@ -391,13 +395,20 @@ static void dmz_reclaim(struct dmz_reclaim *zrc)
 out:
 	if (ret) {
 		dmz_unlock_zone_reclaim(dzone);
-		return;
+		return ret;
 	}
 
-	(void) dmz_flush_metadata(zrc->metadata);
+	ret = dmz_flush_metadata(zrc->metadata);
+	if (ret) {
+		dmz_dev_debug(zrc->dev,
+			      "Metadata flush for zone %u failed, err %d\n",
+			      dmz_id(zmd, rzone), ret);
+		return ret;
+	}
 
 	dmz_dev_debug(zrc->dev, "Reclaimed zone %u in %u ms",
 		      dmz_id(zmd, rzone), jiffies_to_msecs(jiffies - start));
+	return 0;
 }
 
 /*
@@ -427,7 +438,7 @@ static bool dmz_should_reclaim(struct dmz_reclaim *zrc)
 		return false;
 
 	/*
-	 * If the percentage of unmappped random zones is low,
+	 * If the percentage of unmapped random zones is low,
 	 * reclaim even if the target is busy.
 	 */
 	return p_unmap_rnd <= DMZ_RECLAIM_LOW_UNMAP_RND;
@@ -442,6 +453,10 @@ static void dmz_reclaim_work(struct work_struct *work)
 	struct dmz_metadata *zmd = zrc->metadata;
 	unsigned int nr_rnd, nr_unmap_rnd;
 	unsigned int p_unmap_rnd;
+	int ret;
+
+	if (dmz_bdev_is_dying(zrc->dev))
+		return;
 
 	if (!dmz_should_reclaim(zrc)) {
 		mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
@@ -471,7 +486,17 @@ static void dmz_reclaim_work(struct work_struct *work)
 		      (dmz_target_idle(zrc) ? "Idle" : "Busy"),
 		      p_unmap_rnd, nr_unmap_rnd, nr_rnd);
 
-	dmz_reclaim(zrc);
+	ret = dmz_do_reclaim(zrc);
+	if (ret) {
+		dmz_dev_debug(zrc->dev, "Reclaim error %d\n", ret);
+		if (ret == -EIO)
+			/*
+			 * LLD might be performing some error handling sequence
+			 * at the underlying device. To not interfere, do not
+			 * attempt to schedule the next reclaim run immediately.
+			 */
+			return;
+	}
 
 	dmz_schedule_reclaim(zrc);
 }
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index 51d029bbb740..31478fef6032 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
  *
@@ -133,6 +134,8 @@ static int dmz_submit_bio(struct dmz_target *dmz, struct dm_zone *zone,
 
 	refcount_inc(&bioctx->ref);
 	generic_make_request(clone);
+	if (clone->bi_status == BLK_STS_IOERR)
+		return -EIO;
 
 	if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone))
 		zone->wp_block += nr_blocks;
@@ -277,8 +280,8 @@ static int dmz_handle_buffered_write(struct dmz_target *dmz,
 
 	/* Get the buffer zone. One will be allocated if needed */
 	bzone = dmz_get_chunk_buffer(zmd, zone);
-	if (!bzone)
-		return -ENOSPC;
+	if (IS_ERR(bzone))
+		return PTR_ERR(bzone);
 
 	if (dmz_is_readonly(bzone))
 		return -EROFS;
@@ -389,6 +392,11 @@ static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
 
 	dmz_lock_metadata(zmd);
 
+	if (dmz->dev->flags & DMZ_BDEV_DYING) {
+		ret = -EIO;
+		goto out;
+	}
+
 	/*
 	 * Get the data zone mapping the chunk. There may be no
 	 * mapping for read and discard. If a mapping is obtained,
@@ -493,6 +501,8 @@ static void dmz_flush_work(struct work_struct *work)
 
 	/* Flush dirty metadata blocks */
 	ret = dmz_flush_metadata(dmz->metadata);
+	if (ret)
+		dmz_dev_debug(dmz->dev, "Metadata flush failed, rc=%d\n", ret);
 
 	/* Process queued flush requests */
 	while (1) {
@@ -513,22 +523,24 @@ static void dmz_flush_work(struct work_struct *work)
  * Get a chunk work and start it to process a new BIO.
  * If the BIO chunk has no work yet, create one.
  */
-static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
+static int dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
 {
 	unsigned int chunk = dmz_bio_chunk(dmz->dev, bio);
 	struct dm_chunk_work *cw;
+	int ret = 0;
 
 	mutex_lock(&dmz->chunk_lock);
 
 	/* Get the BIO chunk work. If one is not active yet, create one */
 	cw = radix_tree_lookup(&dmz->chunk_rxtree, chunk);
 	if (!cw) {
-		int ret;
 
 		/* Create a new chunk work */
 		cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOIO);
-		if (!cw)
+		if (unlikely(!cw)) {
+			ret = -ENOMEM;
 			goto out;
+		}
 
 		INIT_WORK(&cw->work, dmz_chunk_work);
 		refcount_set(&cw->refcount, 0);
@@ -539,7 +551,6 @@ static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
 		ret = radix_tree_insert(&dmz->chunk_rxtree, chunk, cw);
 		if (unlikely(ret)) {
 			kfree(cw);
-			cw = NULL;
 			goto out;
 		}
 	}
@@ -547,10 +558,38 @@ static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
 	bio_list_add(&cw->bio_list, bio);
 	dmz_get_chunk_work(cw);
 
+	dmz_reclaim_bio_acc(dmz->reclaim);
 	if (queue_work(dmz->chunk_wq, &cw->work))
 		dmz_get_chunk_work(cw);
 out:
 	mutex_unlock(&dmz->chunk_lock);
+	return ret;
+}
+
+/*
+ * Check the backing device availability. If it's on the way out,
+ * start failing I/O. Reclaim and metadata components also call this
+ * function to cleanly abort operation in the event of such failure.
+ */
+bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev)
+{
+	struct gendisk *disk;
+
+	if (!(dmz_dev->flags & DMZ_BDEV_DYING)) {
+		disk = dmz_dev->bdev->bd_disk;
+		if (blk_queue_dying(bdev_get_queue(dmz_dev->bdev))) {
+			dmz_dev_warn(dmz_dev, "Backing device queue dying");
+			dmz_dev->flags |= DMZ_BDEV_DYING;
+		} else if (disk->fops->check_events) {
+			if (disk->fops->check_events(disk, 0) &
+					DISK_EVENT_MEDIA_CHANGE) {
+				dmz_dev_warn(dmz_dev, "Backing device offline");
+				dmz_dev->flags |= DMZ_BDEV_DYING;
+			}
+		}
+	}
+
+	return dmz_dev->flags & DMZ_BDEV_DYING;
 }
 
 /*
@@ -564,6 +603,10 @@ static int dmz_map(struct dm_target *ti, struct bio *bio)
 	sector_t sector = bio->bi_iter.bi_sector;
 	unsigned int nr_sectors = bio_sectors(bio);
 	sector_t chunk_sector;
+	int ret;
+
+	if (dmz_bdev_is_dying(dmz->dev))
+		return DM_MAPIO_KILL;
 
 	dmz_dev_debug(dev, "BIO op %d sector %llu + %u => chunk %llu, block %llu, %u blocks",
 		      bio_op(bio), (unsigned long long)sector, nr_sectors,
@@ -601,8 +644,14 @@ static int dmz_map(struct dm_target *ti, struct bio *bio)
 		dm_accept_partial_bio(bio, dev->zone_nr_sectors - chunk_sector);
 
 	/* Now ready to handle this BIO */
-	dmz_reclaim_bio_acc(dmz->reclaim);
-	dmz_queue_chunk_work(dmz, bio);
+	ret = dmz_queue_chunk_work(dmz, bio);
+	if (ret) {
+		dmz_dev_debug(dmz->dev,
+			      "BIO op %d, can't process chunk %llu, err %i\n",
+			      bio_op(bio), (u64)dmz_bio_chunk(dmz->dev, bio),
+			      ret);
+		return DM_MAPIO_REQUEUE;
+	}
 
 	return DM_MAPIO_SUBMITTED;
 }
@@ -855,6 +904,9 @@ static int dmz_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
 {
 	struct dmz_target *dmz = ti->private;
 
+	if (dmz_bdev_is_dying(dmz->dev))
+		return -ENODEV;
+
 	*bdev = dmz->dev->bdev;
 
 	return 0;
diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
index ed8de49c9a08..d8e70b0ade35 100644
--- a/drivers/md/dm-zoned.h
+++ b/drivers/md/dm-zoned.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
  *
@@ -56,6 +57,8 @@ struct dmz_dev {
 
 	unsigned int		nr_zones;
 
+	unsigned int		flags;
+
 	sector_t		zone_nr_sectors;
 	unsigned int		zone_nr_sectors_shift;
 
@@ -67,6 +70,9 @@ struct dmz_dev {
 				 (dev)->zone_nr_sectors_shift)
 #define dmz_chunk_block(dev, b)	((b) & ((dev)->zone_nr_blocks - 1))
 
+/* Device flags. */
+#define DMZ_BDEV_DYING		(1 << 0)
+
 /*
  * Zone descriptor.
  */
@@ -245,4 +251,9 @@ void dmz_resume_reclaim(struct dmz_reclaim *zrc);
 void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc);
 void dmz_schedule_reclaim(struct dmz_reclaim *zrc);
 
+/*
+ * Functions defined in dm-zoned-target.c
+ */
+bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev);
+
 #endif /* DM_ZONED_H */
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 58b319757b1e..8aae0624a297 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -628,39 +628,40 @@ static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
 
 	new_parent = shadow_current(s);
 
+	pn = dm_block_data(new_parent);
+	size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
+		sizeof(__le64) : s->info->value_type.size;
+
+	/* create & init the left block */
 	r = new_block(s->info, &left);
 	if (r < 0)
 		return r;
 
+	ln = dm_block_data(left);
+	nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
+
+	ln->header.flags = pn->header.flags;
+	ln->header.nr_entries = cpu_to_le32(nr_left);
+	ln->header.max_entries = pn->header.max_entries;
+	ln->header.value_size = pn->header.value_size;
+	memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
+	memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
+
+	/* create & init the right block */
 	r = new_block(s->info, &right);
 	if (r < 0) {
 		unlock_block(s->info, left);
 		return r;
 	}
 
-	pn = dm_block_data(new_parent);
-	ln = dm_block_data(left);
 	rn = dm_block_data(right);
-
-	nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
 	nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;
 
-	ln->header.flags = pn->header.flags;
-	ln->header.nr_entries = cpu_to_le32(nr_left);
-	ln->header.max_entries = pn->header.max_entries;
-	ln->header.value_size = pn->header.value_size;
-
 	rn->header.flags = pn->header.flags;
 	rn->header.nr_entries = cpu_to_le32(nr_right);
 	rn->header.max_entries = pn->header.max_entries;
 	rn->header.value_size = pn->header.value_size;
-
-	memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
 	memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));
-
-	size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
-		sizeof(__le64) : s->info->value_type.size;
-	memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
 	memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
 	       nr_right * size);
 
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index aec449243966..25328582cc48 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -249,7 +249,7 @@ static int out(struct sm_metadata *smm)
 	}
 
 	if (smm->recursion_count == 1)
-		apply_bops(smm);
+		r = apply_bops(smm);
 
 	smm->recursion_count--;