Merge tag 'dm-4.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Most attention this cycle went to optimizing blk-mq request-based DM
   (dm-mq) that is used exclussively by DM multipath:

     - A stable fix for dm-mq that eliminates excessive context
       switching offers the biggest performance improvement (for both
       IOPs and throughput).

     - But more work is needed, during the next cycle, to reduce
       spinlock contention in DM multipath on large NUMA systems.

 - A stable fix for a NULL pointer seen when DM stats is enabled on a DM
   multipath device that must requeue an IO due to path failure.

 - A stable fix for DM snapshot to disallow the COW and origin devices
   from being identical.  This amounts to graceful failure in the face
   of userspace error because these devices shouldn't ever be identical.

 - Stable fixes for DM cache and DM thin provisioning to address crashes
   seen if/when their respective metadata device experiences failures
   that cause the transition to 'fail_io' mode.

 - The DM cache 'mq' policy is now an alias for the 'smq' policy.  The
   'smq' policy proved to be consistently better than 'mq'.  As such
   'mq', with all its complex user-facing tunables, has been eliminated.

 - Improve DM thin provisioning to consistently return -ENOSPC once the
   thin-pool's data volume is out of space.

 - Improve DM core to properly handle error propagation if
   bio_integrity_clone() fails in clone_bio().

 - Other small cleanups and improvements to DM core.

* tag 'dm-4.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (41 commits)
  dm: fix rq_end_stats() NULL pointer in dm_requeue_original_request()
  dm thin: consistently return -ENOSPC if pool has run out of data space
  dm cache: bump the target version
  dm cache: make sure every metadata function checks fail_io
  dm: add missing newline between DM_DEBUG_BLOCK_STACK_TRACING and DM_BUFIO
  dm cache policy smq: clarify that mq registration failure was for 'mq'
  dm: return error if bio_integrity_clone() fails in clone_bio()
  dm thin metadata: don't issue prefetches if a transaction abort has failed
  dm snapshot: disallow the COW and origin devices from being identical
  dm cache: make the 'mq' policy an alias for 'smq'
  dm: drop unnecessary assignment of md->queue
  dm: reorder 'struct mapped_device' members to fix alignment and holes
  dm: remove dummy definition of 'struct dm_table'
  dm: add 'dm_numa_node' module parameter
  dm thin metadata: remove needless newline from subtree_dec() DMERR message
  dm mpath: cleanup reinstate_path() et al based on code review
  dm mpath: remove __pgpath_busy forward declaration, rename to pgpath_busy
  dm mpath: switch from 'unsigned' to 'bool' for flags where appropriate
  dm round robin: use percpu 'repeat_count' and 'current_path'
  dm path selector: remove 'repeat_count' return from .select_path hook
  ...

1 files changed, 326 insertions, 274 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index dd834927bc66..be4905769a45 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -106,14 +106,6 @@ struct dm_rq_clone_bio_info {
 	struct bio clone;
 };
 
-union map_info *dm_get_rq_mapinfo(struct request *rq)
-{
-	if (rq && rq->end_io_data)
-		return &((struct dm_rq_target_io *)rq->end_io_data)->info;
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
-
 #define MINOR_ALLOCED ((void *)-1)
 
 /*
@@ -129,28 +121,18 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
 #define DMF_SUSPENDED_INTERNALLY 7
 
 /*
- * A dummy definition to make RCU happy.
- * struct dm_table should never be dereferenced in this file.
- */
-struct dm_table {
-	int undefined__;
-};
-
-/*
  * Work processed by per-device workqueue.
  */
 struct mapped_device {
 	struct srcu_struct io_barrier;
 	struct mutex suspend_lock;
-	atomic_t holders;
-	atomic_t open_count;
 
 	/*
-	 * The current mapping.
+	 * The current mapping (struct dm_table *).
 	 * Use dm_get_live_table{_fast} or take suspend_lock for
 	 * dereference.
 	 */
-	struct dm_table __rcu *map;
+	void __rcu *map;
 
 	struct list_head table_devices;
 	struct mutex table_devices_lock;
@@ -158,10 +140,16 @@ struct mapped_device {
 	unsigned long flags;
 
 	struct request_queue *queue;
+	int numa_node_id;
+
 	unsigned type;
 	/* Protect queue and type against concurrent access. */
 	struct mutex type_lock;
 
+	atomic_t holders;
+	atomic_t open_count;
+
+	struct dm_target *immutable_target;
 	struct target_type *immutable_target_type;
 
 	struct gendisk *disk;
@@ -175,8 +163,20 @@ struct mapped_device {
 	atomic_t pending[2];
 	wait_queue_head_t wait;
 	struct work_struct work;
-	struct bio_list deferred;
 	spinlock_t deferred_lock;
+	struct bio_list deferred;
+
+	/*
+	 * Event handling.
+	 */
+	wait_queue_head_t eventq;
+	atomic_t event_nr;
+	atomic_t uevent_seq;
+	struct list_head uevent_list;
+	spinlock_t uevent_lock; /* Protect access to uevent_list */
+
+	/* the number of internal suspends */
+	unsigned internal_suspend_count;
 
 	/*
 	 * Processing queue (flush)
@@ -192,32 +192,21 @@ struct mapped_device {
 	struct bio_set *bs;
 
 	/*
-	 * Event handling.
-	 */
-	atomic_t event_nr;
-	wait_queue_head_t eventq;
-	atomic_t uevent_seq;
-	struct list_head uevent_list;
-	spinlock_t uevent_lock; /* Protect access to uevent_list */
-
-	/*
 	 * freeze/thaw support require holding onto a super block
 	 */
 	struct super_block *frozen_sb;
-	struct block_device *bdev;
 
 	/* forced geometry settings */
 	struct hd_geometry geometry;
 
+	struct block_device *bdev;
+
 	/* kobject and completion */
 	struct dm_kobject_holder kobj_holder;
 
 	/* zero-length flush that will be cloned and submitted to targets */
 	struct bio flush_bio;
 
-	/* the number of internal suspends */
-	unsigned internal_suspend_count;
-
 	struct dm_stats stats;
 
 	struct kthread_worker kworker;
@@ -230,8 +219,9 @@ struct mapped_device {
 	ktime_t last_rq_start_time;
 
 	/* for blk-mq request-based DM support */
-	struct blk_mq_tag_set tag_set;
-	bool use_blk_mq;
+	struct blk_mq_tag_set *tag_set;
+	bool use_blk_mq:1;
+	bool init_tio_pdu:1;
 };
 
 #ifdef CONFIG_DM_MQ_DEFAULT
@@ -240,10 +230,19 @@ static bool use_blk_mq = true;
 static bool use_blk_mq = false;
 #endif
 
+#define DM_MQ_NR_HW_QUEUES 1
+#define DM_MQ_QUEUE_DEPTH 2048
+#define DM_NUMA_NODE NUMA_NO_NODE
+
+static unsigned dm_mq_nr_hw_queues = DM_MQ_NR_HW_QUEUES;
+static unsigned dm_mq_queue_depth = DM_MQ_QUEUE_DEPTH;
+static int dm_numa_node = DM_NUMA_NODE;
+
 bool dm_use_blk_mq(struct mapped_device *md)
 {
 	return md->use_blk_mq;
 }
+EXPORT_SYMBOL_GPL(dm_use_blk_mq);
 
 /*
  * For mempools pre-allocation at the table loading time.
@@ -277,6 +276,27 @@ static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
  */
 static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
 
+static int __dm_get_module_param_int(int *module_param, int min, int max)
+{
+	int param = ACCESS_ONCE(*module_param);
+	int modified_param = 0;
+	bool modified = true;
+
+	if (param < min)
+		modified_param = min;
+	else if (param > max)
+		modified_param = max;
+	else
+		modified = false;
+
+	if (modified) {
+		(void)cmpxchg(module_param, param, modified_param);
+		param = modified_param;
+	}
+
+	return param;
+}
+
 static unsigned __dm_get_module_param(unsigned *module_param,
 				      unsigned def, unsigned max)
 {
@@ -310,6 +330,23 @@ unsigned dm_get_reserved_rq_based_ios(void)
 }
 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
 
+static unsigned dm_get_blk_mq_nr_hw_queues(void)
+{
+	return __dm_get_module_param(&dm_mq_nr_hw_queues, 1, 32);
+}
+
+static unsigned dm_get_blk_mq_queue_depth(void)
+{
+	return __dm_get_module_param(&dm_mq_queue_depth,
+				     DM_MQ_QUEUE_DEPTH, BLK_MQ_MAX_DEPTH);
+}
+
+static unsigned dm_get_numa_node(void)
+{
+	return __dm_get_module_param_int(&dm_numa_node,
+					 DM_NUMA_NODE, num_online_nodes() - 1);
+}
+
 static int __init local_init(void)
 {
 	int r = -ENOMEM;
@@ -323,7 +360,7 @@ static int __init local_init(void)
 	if (!_rq_tio_cache)
 		goto out_free_io_cache;
 
-	_rq_cache = kmem_cache_create("dm_clone_request", sizeof(struct request),
+	_rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
 				      __alignof__(struct request), 0, NULL);
 	if (!_rq_cache)
 		goto out_free_rq_tio_cache;
@@ -556,16 +593,17 @@ static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return dm_get_geometry(md, geo);
 }
 
-static int dm_get_live_table_for_ioctl(struct mapped_device *md,
-		struct dm_target **tgt, struct block_device **bdev,
-		fmode_t *mode, int *srcu_idx)
+static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
+				  struct block_device **bdev,
+				  fmode_t *mode)
 {
+	struct dm_target *tgt;
 	struct dm_table *map;
-	int r;
+	int srcu_idx, r;
 
 retry:
 	r = -ENOTTY;
-	map = dm_get_live_table(md, srcu_idx);
+	map = dm_get_live_table(md, &srcu_idx);
 	if (!map || !dm_table_get_size(map))
 		goto out;
 
@@ -573,9 +611,8 @@ retry:
 	if (dm_table_get_num_targets(map) != 1)
 		goto out;
 
-	*tgt = dm_table_get_target(map, 0);
-
-	if (!(*tgt)->type->prepare_ioctl)
+	tgt = dm_table_get_target(map, 0);
+	if (!tgt->type->prepare_ioctl)
 		goto out;
 
 	if (dm_suspended_md(md)) {
@@ -583,14 +620,16 @@ retry:
 		goto out;
 	}
 
-	r = (*tgt)->type->prepare_ioctl(*tgt, bdev, mode);
+	r = tgt->type->prepare_ioctl(tgt, bdev, mode);
 	if (r < 0)
 		goto out;
 
+	bdgrab(*bdev);
+	dm_put_live_table(md, srcu_idx);
 	return r;
 
 out:
-	dm_put_live_table(md, *srcu_idx);
+	dm_put_live_table(md, srcu_idx);
 	if (r == -ENOTCONN && !fatal_signal_pending(current)) {
 		msleep(10);
 		goto retry;
@@ -602,11 +641,9 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned int cmd, unsigned long arg)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
-	struct dm_target *tgt;
-	struct block_device *tgt_bdev = NULL;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &tgt_bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -621,9 +658,9 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
 			goto out;
 	}
 
-	r =  __blkdev_driver_ioctl(tgt_bdev, mode, cmd, arg);
+	r =  __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 out:
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
@@ -642,24 +679,24 @@ static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
 	bio_put(&tio->clone);
 }
 
-static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
-					    gfp_t gfp_mask)
+static struct dm_rq_target_io *alloc_old_rq_tio(struct mapped_device *md,
+						gfp_t gfp_mask)
 {
 	return mempool_alloc(md->io_pool, gfp_mask);
 }
 
-static void free_rq_tio(struct dm_rq_target_io *tio)
+static void free_old_rq_tio(struct dm_rq_target_io *tio)
 {
 	mempool_free(tio, tio->md->io_pool);
 }
 
-static struct request *alloc_clone_request(struct mapped_device *md,
-					   gfp_t gfp_mask)
+static struct request *alloc_old_clone_request(struct mapped_device *md,
+					       gfp_t gfp_mask)
 {
 	return mempool_alloc(md->rq_pool, gfp_mask);
 }
 
-static void free_clone_request(struct mapped_device *md, struct request *rq)
+static void free_old_clone_request(struct mapped_device *md, struct request *rq)
 {
 	mempool_free(rq, md->rq_pool);
 }
@@ -827,7 +864,7 @@ int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 	mutex_lock(&md->table_devices_lock);
 	td = find_table_device(&md->table_devices, dev, mode);
 	if (!td) {
-		td = kmalloc(sizeof(*td), GFP_KERNEL);
+		td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
 		if (!td) {
 			mutex_unlock(&md->table_devices_lock);
 			return -ENOMEM;
@@ -1109,12 +1146,8 @@ static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
 	 * back into ->request_fn() could deadlock attempting to grab the
 	 * queue lock again.
 	 */
-	if (run_queue) {
-		if (md->queue->mq_ops)
-			blk_mq_run_hw_queues(md->queue, true);
-		else
-			blk_run_queue_async(md->queue);
-	}
+	if (!md->queue->mq_ops && run_queue)
+		blk_run_queue_async(md->queue);
 
 	/*
 	 * dm_put() must be at the end of this function. See the comment above
@@ -1134,15 +1167,10 @@ static void free_rq_clone(struct request *clone)
 		tio->ti->type->release_clone_rq(clone);
 	else if (!md->queue->mq_ops)
 		/* request_fn queue stacked on request_fn queue(s) */
-		free_clone_request(md, clone);
-	/*
-	 * NOTE: for the blk-mq queue stacked on request_fn queue(s) case:
-	 * no need to call free_clone_request() because we leverage blk-mq by
-	 * allocating the clone at the end of the blk-mq pdu (see: clone_rq)
-	 */
+		free_old_clone_request(md, clone);
 
 	if (!md->queue->mq_ops)
-		free_rq_tio(tio);
+		free_old_rq_tio(tio);
 }
 
 /*
@@ -1192,13 +1220,13 @@ static void dm_unprep_request(struct request *rq)
 	if (clone)
 		free_rq_clone(clone);
 	else if (!tio->md->queue->mq_ops)
-		free_rq_tio(tio);
+		free_old_rq_tio(tio);
 }
 
 /*
  * Requeue the original request of a clone.
  */
-static void old_requeue_request(struct request *rq)
+static void dm_old_requeue_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 	unsigned long flags;
@@ -1209,45 +1237,57 @@ static void old_requeue_request(struct request *rq)
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
+static void dm_mq_requeue_request(struct request *rq)
+{
+	struct request_queue *q = rq->q;
+	unsigned long flags;
+
+	blk_mq_requeue_request(rq);
+	spin_lock_irqsave(q->queue_lock, flags);
+	if (!blk_queue_stopped(q))
+		blk_mq_kick_requeue_list(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
 static void dm_requeue_original_request(struct mapped_device *md,
 					struct request *rq)
 {
 	int rw = rq_data_dir(rq);
 
+	rq_end_stats(md, rq);
 	dm_unprep_request(rq);
 
-	rq_end_stats(md, rq);
 	if (!rq->q->mq_ops)
-		old_requeue_request(rq);
-	else {
-		blk_mq_requeue_request(rq);
-		blk_mq_kick_requeue_list(rq->q);
-	}
+		dm_old_requeue_request(rq);
+	else
+		dm_mq_requeue_request(rq);
 
 	rq_completed(md, rw, false);
 }
 
-static void old_stop_queue(struct request_queue *q)
+static void dm_old_stop_queue(struct request_queue *q)
 {
 	unsigned long flags;
 
-	if (blk_queue_stopped(q))
+	spin_lock_irqsave(q->queue_lock, flags);
+	if (blk_queue_stopped(q)) {
+		spin_unlock_irqrestore(q->queue_lock, flags);
 		return;
+	}
 
-	spin_lock_irqsave(q->queue_lock, flags);
 	blk_stop_queue(q);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
-static void stop_queue(struct request_queue *q)
+static void dm_stop_queue(struct request_queue *q)
 {
 	if (!q->mq_ops)
-		old_stop_queue(q);
+		dm_old_stop_queue(q);
 	else
 		blk_mq_stop_hw_queues(q);
 }
 
-static void old_start_queue(struct request_queue *q)
+static void dm_old_start_queue(struct request_queue *q)
 {
 	unsigned long flags;
 
@@ -1257,12 +1297,14 @@ static void old_start_queue(struct request_queue *q)
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
-static void start_queue(struct request_queue *q)
+static void dm_start_queue(struct request_queue *q)
 {
 	if (!q->mq_ops)
-		old_start_queue(q);
-	else
+		dm_old_start_queue(q);
+	else {
 		blk_mq_start_stopped_hw_queues(q, true);
+		blk_mq_kick_requeue_list(q);
+	}
 }
 
 static void dm_done(struct request *clone, int error, bool mapped)
@@ -1313,7 +1355,7 @@ static void dm_softirq_done(struct request *rq)
 		if (!rq->q->mq_ops) {
 			blk_end_request_all(rq, tio->error);
 			rq_completed(tio->md, rw, false);
-			free_rq_tio(tio);
+			free_old_rq_tio(tio);
 		} else {
 			blk_mq_end_request(rq, tio->error);
 			rq_completed(tio->md, rw, false);
@@ -1336,7 +1378,10 @@ static void dm_complete_request(struct request *rq, int error)
 	struct dm_rq_target_io *tio = tio_from_request(rq);
 
 	tio->error = error;
-	blk_complete_request(rq);
+	if (!rq->q->mq_ops)
+		blk_complete_request(rq);
+	else
+		blk_mq_complete_request(rq, error);
 }
 
 /*
@@ -1352,7 +1397,7 @@ static void dm_kill_unmapped_request(struct request *rq, int error)
 }
 
 /*
- * Called with the clone's queue lock held (for non-blk-mq)
+ * Called with the clone's queue lock held (in the case of .request_fn)
  */
 static void end_clone_request(struct request *clone, int error)
 {
@@ -1522,21 +1567,26 @@ static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
 /*
  * Creates a bio that consists of range of complete bvecs.
  */
-static void clone_bio(struct dm_target_io *tio, struct bio *bio,
-		      sector_t sector, unsigned len)
+static int clone_bio(struct dm_target_io *tio, struct bio *bio,
+		     sector_t sector, unsigned len)
 {
 	struct bio *clone = &tio->clone;
 
 	__bio_clone_fast(clone, bio);
 
-	if (bio_integrity(bio))
-		bio_integrity_clone(clone, bio, GFP_NOIO);
+	if (bio_integrity(bio)) {
+		int r = bio_integrity_clone(clone, bio, GFP_NOIO);
+		if (r < 0)
+			return r;
+	}
 
 	bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
 	clone->bi_iter.bi_size = to_bytes(len);
 
 	if (bio_integrity(bio))
 		bio_integrity_trim(clone, 0, len);
+
+	return 0;
 }
 
 static struct dm_target_io *alloc_tio(struct clone_info *ci,
@@ -1593,13 +1643,14 @@ static int __send_empty_flush(struct clone_info *ci)
 	return 0;
 }
 
-static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
+static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
 				     sector_t sector, unsigned *len)
 {
 	struct bio *bio = ci->bio;
 	struct dm_target_io *tio;
 	unsigned target_bio_nr;
 	unsigned num_target_bios = 1;
+	int r = 0;
 
 	/*
 	 * Does the target want to receive duplicate copies of the bio?
@@ -1610,9 +1661,13 @@ static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti
 	for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
 		tio = alloc_tio(ci, ti, target_bio_nr);
 		tio->len_ptr = len;
-		clone_bio(tio, bio, sector, *len);
+		r = clone_bio(tio, bio, sector, *len);
+		if (r < 0)
+			break;
 		__map_bio(tio);
 	}
+
+	return r;
 }
 
 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
@@ -1689,6 +1744,7 @@ static int __split_and_process_non_flush(struct clone_info *ci)
 	struct bio *bio = ci->bio;
 	struct dm_target *ti;
 	unsigned len;
+	int r;
 
 	if (unlikely(bio->bi_rw & REQ_DISCARD))
 		return __send_discard(ci);
@@ -1701,7 +1757,9 @@ static int __split_and_process_non_flush(struct clone_info *ci)
 
 	len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
 
-	__clone_and_map_data_bio(ci, ti, ci->sector, &len);
+	r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
+	if (r < 0)
+		return r;
 
 	ci->sector += len;
 	ci->sector_count -= len;
@@ -1839,28 +1897,22 @@ static int setup_clone(struct request *clone, struct request *rq,
 	return 0;
 }
 
-static struct request *clone_rq(struct request *rq, struct mapped_device *md,
-				struct dm_rq_target_io *tio, gfp_t gfp_mask)
+static struct request *clone_old_rq(struct request *rq, struct mapped_device *md,
+				    struct dm_rq_target_io *tio, gfp_t gfp_mask)
 {
 	/*
-	 * Do not allocate a clone if tio->clone was already set
-	 * (see: dm_mq_queue_rq).
+	 * Create clone for use with .request_fn request_queue
 	 */
-	bool alloc_clone = !tio->clone;
 	struct request *clone;
 
-	if (alloc_clone) {
-		clone = alloc_clone_request(md, gfp_mask);
-		if (!clone)
-			return NULL;
-	} else
-		clone = tio->clone;
+	clone = alloc_old_clone_request(md, gfp_mask);
+	if (!clone)
+		return NULL;
 
 	blk_rq_init(NULL, clone);
 	if (setup_clone(clone, rq, tio, gfp_mask)) {
 		/* -ENOMEM */
-		if (alloc_clone)
-			free_clone_request(md, clone);
+		free_old_clone_request(md, clone);
 		return NULL;
 	}
 
@@ -1877,29 +1929,40 @@ static void init_tio(struct dm_rq_target_io *tio, struct request *rq,
 	tio->clone = NULL;
 	tio->orig = rq;
 	tio->error = 0;
-	memset(&tio->info, 0, sizeof(tio->info));
+	/*
+	 * Avoid initializing info for blk-mq; it passes
+	 * target-specific data through info.ptr
+	 * (see: dm_mq_init_request)
+	 */
+	if (!md->init_tio_pdu)
+		memset(&tio->info, 0, sizeof(tio->info));
 	if (md->kworker_task)
 		init_kthread_work(&tio->work, map_tio_request);
 }
 
-static struct dm_rq_target_io *prep_tio(struct request *rq,
-					struct mapped_device *md, gfp_t gfp_mask)
+static struct dm_rq_target_io *dm_old_prep_tio(struct request *rq,
+					       struct mapped_device *md,
+					       gfp_t gfp_mask)
 {
 	struct dm_rq_target_io *tio;
 	int srcu_idx;
 	struct dm_table *table;
 
-	tio = alloc_rq_tio(md, gfp_mask);
+	tio = alloc_old_rq_tio(md, gfp_mask);
 	if (!tio)
 		return NULL;
 
 	init_tio(tio, rq, md);
 
 	table = dm_get_live_table(md, &srcu_idx);
+	/*
+	 * Must clone a request if this .request_fn DM device
+	 * is stacked on .request_fn device(s).
+	 */
 	if (!dm_table_mq_request_based(table)) {
-		if (!clone_rq(rq, md, tio, gfp_mask)) {
+		if (!clone_old_rq(rq, md, tio, gfp_mask)) {
 			dm_put_live_table(md, srcu_idx);
-			free_rq_tio(tio);
+			free_old_rq_tio(tio);
 			return NULL;
 		}
 	}
@@ -1911,7 +1974,7 @@ static struct dm_rq_target_io *prep_tio(struct request *rq,
 /*
  * Called with the queue lock held.
  */
-static int dm_prep_fn(struct request_queue *q, struct request *rq)
+static int dm_old_prep_fn(struct request_queue *q, struct request *rq)
 {
 	struct mapped_device *md = q->queuedata;
 	struct dm_rq_target_io *tio;
@@ -1921,7 +1984,7 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
 		return BLKPREP_KILL;
 	}
 
-	tio = prep_tio(rq, md, GFP_ATOMIC);
+	tio = dm_old_prep_tio(rq, md, GFP_ATOMIC);
 	if (!tio)
 		return BLKPREP_DEFER;
 
@@ -2079,12 +2142,18 @@ static bool dm_request_peeked_before_merge_deadline(struct mapped_device *md)
 static void dm_request_fn(struct request_queue *q)
 {
 	struct mapped_device *md = q->queuedata;
-	int srcu_idx;
-	struct dm_table *map = dm_get_live_table(md, &srcu_idx);
-	struct dm_target *ti;
+	struct dm_target *ti = md->immutable_target;
 	struct request *rq;
 	struct dm_rq_target_io *tio;
-	sector_t pos;
+	sector_t pos = 0;
+
+	if (unlikely(!ti)) {
+		int srcu_idx;
+		struct dm_table *map = dm_get_live_table(md, &srcu_idx);
+
+		ti = dm_table_find_target(map, pos);
+		dm_put_live_table(md, srcu_idx);
+	}
 
 	/*
 	 * For suspend, check blk_queue_stopped() and increment
@@ -2095,33 +2164,21 @@ static void dm_request_fn(struct request_queue *q)
 	while (!blk_queue_stopped(q)) {
 		rq = blk_peek_request(q);
 		if (!rq)
-			goto out;
+			return;
 
 		/* always use block 0 to find the target for flushes for now */
 		pos = 0;
 		if (!(rq->cmd_flags & REQ_FLUSH))
 			pos = blk_rq_pos(rq);
 
-		ti = dm_table_find_target(map, pos);
-		if (!dm_target_is_valid(ti)) {
-			/*
-			 * Must perform setup, that rq_completed() requires,
-			 * before calling dm_kill_unmapped_request
-			 */
-			DMERR_LIMIT("request attempted access beyond the end of device");
-			dm_start_request(md, rq);
-			dm_kill_unmapped_request(rq, -EIO);
-			continue;
+		if ((dm_request_peeked_before_merge_deadline(md) &&
+		     md_in_flight(md) && rq->bio && rq->bio->bi_vcnt == 1 &&
+		     md->last_rq_pos == pos && md->last_rq_rw == rq_data_dir(rq)) ||
+		    (ti->type->busy && ti->type->busy(ti))) {
+			blk_delay_queue(q, HZ / 100);
+			return;
 		}
 
-		if (dm_request_peeked_before_merge_deadline(md) &&
-		    md_in_flight(md) && rq->bio && rq->bio->bi_vcnt == 1 &&
-		    md->last_rq_pos == pos && md->last_rq_rw == rq_data_dir(rq))
-			goto delay_and_out;
-
-		if (ti->type->busy && ti->type->busy(ti))
-			goto delay_and_out;
-
 		dm_start_request(md, rq);
 
 		tio = tio_from_request(rq);
@@ -2130,13 +2187,6 @@ static void dm_request_fn(struct request_queue *q)
 		queue_kthread_work(&md->kworker, &tio->work);
 		BUG_ON(!irqs_disabled());
 	}
-
-	goto out;
-
-delay_and_out:
-	blk_delay_queue(q, HZ / 100);
-out:
-	dm_put_live_table(md, srcu_idx);
 }
 
 static int dm_any_congested(void *congested_data, int bdi_bits)
@@ -2146,19 +2196,18 @@ static int dm_any_congested(void *congested_data, int bdi_bits)
 	struct dm_table *map;
 
 	if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
-		map = dm_get_live_table_fast(md);
-		if (map) {
+		if (dm_request_based(md)) {
 			/*
-			 * Request-based dm cares about only own queue for
-			 * the query about congestion status of request_queue
+			 * With request-based DM we only need to check the
+			 * top-level queue for congestion.
 			 */
-			if (dm_request_based(md))
-				r = md->queue->backing_dev_info.wb.state &
-				    bdi_bits;
-			else
+			r = md->queue->backing_dev_info.wb.state & bdi_bits;
+		} else {
+			map = dm_get_live_table_fast(md);
+			if (map)
 				r = dm_table_any_congested(map, bdi_bits);
+			dm_put_live_table_fast(md);
 		}
-		dm_put_live_table_fast(md);
 	}
 
 	return r;
@@ -2238,7 +2287,7 @@ static void dm_init_md_queue(struct mapped_device *md)
 	md->queue->backing_dev_info.congested_data = md;
 }
 
-static void dm_init_old_md_queue(struct mapped_device *md)
+static void dm_init_normal_md_queue(struct mapped_device *md)
 {
 	md->use_blk_mq = false;
 	dm_init_md_queue(md);
@@ -2285,10 +2334,11 @@ static void cleanup_mapped_device(struct mapped_device *md)
  */
 static struct mapped_device *alloc_dev(int minor)
 {
-	int r;
-	struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL);
+	int r, numa_node_id = dm_get_numa_node();
+	struct mapped_device *md;
 	void *old_md;
 
+	md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
 	if (!md) {
 		DMWARN("unable to allocate device, out of memory.");
 		return NULL;
@@ -2309,7 +2359,9 @@ static struct mapped_device *alloc_dev(int minor)
 	if (r < 0)
 		goto bad_io_barrier;
 
+	md->numa_node_id = numa_node_id;
 	md->use_blk_mq = use_blk_mq;
+	md->init_tio_pdu = false;
 	md->type = DM_TYPE_NONE;
 	mutex_init(&md->suspend_lock);
 	mutex_init(&md->type_lock);
@@ -2323,13 +2375,13 @@ static struct mapped_device *alloc_dev(int minor)
 	INIT_LIST_HEAD(&md->table_devices);
 	spin_lock_init(&md->uevent_lock);
 
-	md->queue = blk_alloc_queue(GFP_KERNEL);
+	md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
 	if (!md->queue)
 		goto bad;
 
 	dm_init_md_queue(md);
 
-	md->disk = alloc_disk(1);
+	md->disk = alloc_disk_node(1, numa_node_id);
 	if (!md->disk)
 		goto bad;
 
@@ -2393,8 +2445,10 @@ static void free_dev(struct mapped_device *md)
 	unlock_fs(md);
 
 	cleanup_mapped_device(md);
-	if (md->use_blk_mq)
-		blk_mq_free_tag_set(&md->tag_set);
+	if (md->tag_set) {
+		blk_mq_free_tag_set(md->tag_set);
+		kfree(md->tag_set);
+	}
 
 	free_table_devices(&md->table_devices);
 	dm_stats_cleanup(&md->stats);
@@ -2502,13 +2556,20 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
 	 * This must be done before setting the queue restrictions,
 	 * because request-based dm may be run just after the setting.
 	 */
-	if (dm_table_request_based(t))
-		stop_queue(q);
+	if (dm_table_request_based(t)) {
+		dm_stop_queue(q);
+		/*
+		 * Leverage the fact that request-based DM targets are
+		 * immutable singletons and establish md->immutable_target
+		 * - used to optimize both dm_request_fn and dm_mq_queue_rq
+		 */
+		md->immutable_target = dm_table_get_immutable_target(t);
+	}
 
 	__bind_mempools(md, t);
 
 	old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
-	rcu_assign_pointer(md->map, t);
+	rcu_assign_pointer(md->map, (void *)t);
 	md->immutable_target_type = dm_table_get_immutable_target_type(t);
 
 	dm_table_set_restrictions(t, q, limits);
@@ -2574,7 +2635,6 @@ void dm_set_md_type(struct mapped_device *md, unsigned type)
 
 unsigned dm_get_md_type(struct mapped_device *md)
 {
-	BUG_ON(!mutex_is_locked(&md->type_lock));
 	return md->type;
 }
 
@@ -2594,7 +2654,7 @@ struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
 }
 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
 
-static void init_rq_based_worker_thread(struct mapped_device *md)
+static void dm_old_init_rq_based_worker_thread(struct mapped_device *md)
 {
 	/* Initialize the request-based DM worker thread */
 	init_kthread_worker(&md->kworker);
@@ -2603,26 +2663,22 @@ static void init_rq_based_worker_thread(struct mapped_device *md)
 }
 
 /*
- * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
+ * Fully initialize a .request_fn request-based queue.
  */
-static int dm_init_request_based_queue(struct mapped_device *md)
+static int dm_old_init_request_queue(struct mapped_device *md)
 {
-	struct request_queue *q = NULL;
-
 	/* Fully initialize the queue */
-	q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
-	if (!q)
+	if (!blk_init_allocated_queue(md->queue, dm_request_fn, NULL))
 		return -EINVAL;
 
 	/* disable dm_request_fn's merge heuristic by default */
 	md->seq_rq_merge_deadline_usecs = 0;
 
-	md->queue = q;
-	dm_init_old_md_queue(md);
+	dm_init_normal_md_queue(md);
 	blk_queue_softirq_done(md->queue, dm_softirq_done);
-	blk_queue_prep_rq(md->queue, dm_prep_fn);
+	blk_queue_prep_rq(md->queue, dm_old_prep_fn);
 
-	init_rq_based_worker_thread(md);
+	dm_old_init_rq_based_worker_thread(md);
 
 	elv_register_queue(md->queue);
 
@@ -2642,6 +2698,11 @@ static int dm_mq_init_request(void *data, struct request *rq,
 	 */
 	tio->md = md;
 
+	if (md->init_tio_pdu) {
+		/* target-specific per-io data is immediately after the tio */
+		tio->info.ptr = tio + 1;
+	}
+
 	return 0;
 }
 
@@ -2651,28 +2712,15 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct request *rq = bd->rq;
 	struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq);
 	struct mapped_device *md = tio->md;
-	int srcu_idx;
-	struct dm_table *map = dm_get_live_table(md, &srcu_idx);
-	struct dm_target *ti;
-	sector_t pos;
+	struct dm_target *ti = md->immutable_target;
 
-	/* always use block 0 to find the target for flushes for now */
-	pos = 0;
-	if (!(rq->cmd_flags & REQ_FLUSH))
-		pos = blk_rq_pos(rq);
+	if (unlikely(!ti)) {
+		int srcu_idx;
+		struct dm_table *map = dm_get_live_table(md, &srcu_idx);
 
-	ti = dm_table_find_target(map, pos);
-	if (!dm_target_is_valid(ti)) {
+		ti = dm_table_find_target(map, 0);
 		dm_put_live_table(md, srcu_idx);
-		DMERR_LIMIT("request attempted access beyond the end of device");
-		/*
-		 * Must perform setup, that rq_completed() requires,
-		 * before returning BLK_MQ_RQ_QUEUE_ERROR
-		 */
-		dm_start_request(md, rq);
-		return BLK_MQ_RQ_QUEUE_ERROR;
 	}
-	dm_put_live_table(md, srcu_idx);
 
 	if (ti->type->busy && ti->type->busy(ti))
 		return BLK_MQ_RQ_QUEUE_BUSY;
@@ -2688,20 +2736,12 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 	 */
 	tio->ti = ti;
 
-	/* Clone the request if underlying devices aren't blk-mq */
-	if (dm_table_get_type(map) == DM_TYPE_REQUEST_BASED) {
-		/* clone request is allocated at the end of the pdu */
-		tio->clone = (void *)blk_mq_rq_to_pdu(rq) + sizeof(struct dm_rq_target_io);
-		(void) clone_rq(rq, md, tio, GFP_ATOMIC);
-		queue_kthread_work(&md->kworker, &tio->work);
-	} else {
-		/* Direct call is fine since .queue_rq allows allocations */
-		if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
-			/* Undo dm_start_request() before requeuing */
-			rq_end_stats(md, rq);
-			rq_completed(md, rq_data_dir(rq), false);
-			return BLK_MQ_RQ_QUEUE_BUSY;
-		}
+	/* Direct call is fine since .queue_rq allows allocations */
+	if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
+		/* Undo dm_start_request() before requeuing */
+		rq_end_stats(md, rq);
+		rq_completed(md, rq_data_dir(rq), false);
+		return BLK_MQ_RQ_QUEUE_BUSY;
 	}
 
 	return BLK_MQ_RQ_QUEUE_OK;
@@ -2714,47 +2754,56 @@ static struct blk_mq_ops dm_mq_ops = {
 	.init_request = dm_mq_init_request,
 };
 
-static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
+static int dm_mq_init_request_queue(struct mapped_device *md,
+				    struct dm_target *immutable_tgt)
 {
-	unsigned md_type = dm_get_md_type(md);
 	struct request_queue *q;
 	int err;
 
-	memset(&md->tag_set, 0, sizeof(md->tag_set));
-	md->tag_set.ops = &dm_mq_ops;
-	md->tag_set.queue_depth = BLKDEV_MAX_RQ;
-	md->tag_set.numa_node = NUMA_NO_NODE;
-	md->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
-	md->tag_set.nr_hw_queues = 1;
-	if (md_type == DM_TYPE_REQUEST_BASED) {
-		/* make the memory for non-blk-mq clone part of the pdu */
-		md->tag_set.cmd_size = sizeof(struct dm_rq_target_io) + sizeof(struct request);
-	} else
-		md->tag_set.cmd_size = sizeof(struct dm_rq_target_io);
-	md->tag_set.driver_data = md;
-
-	err = blk_mq_alloc_tag_set(&md->tag_set);
+	if (dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) {
+		DMERR("request-based dm-mq may only be stacked on blk-mq device(s)");
+		return -EINVAL;
+	}
+
+	md->tag_set = kzalloc_node(sizeof(struct blk_mq_tag_set), GFP_KERNEL, md->numa_node_id);
+	if (!md->tag_set)
+		return -ENOMEM;
+
+	md->tag_set->ops = &dm_mq_ops;
+	md->tag_set->queue_depth = dm_get_blk_mq_queue_depth();
+	md->tag_set->numa_node = md->numa_node_id;
+	md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+	md->tag_set->nr_hw_queues = dm_get_blk_mq_nr_hw_queues();
+	md->tag_set->driver_data = md;
+
+	md->tag_set->cmd_size = sizeof(struct dm_rq_target_io);
+	if (immutable_tgt && immutable_tgt->per_io_data_size) {
+		/* any target-specific per-io data is immediately after the tio */
+		md->tag_set->cmd_size += immutable_tgt->per_io_data_size;
+		md->init_tio_pdu = true;
+	}
+
+	err = blk_mq_alloc_tag_set(md->tag_set);
 	if (err)
-		return err;
+		goto out_kfree_tag_set;
 
-	q = blk_mq_init_allocated_queue(&md->tag_set, md->queue);
+	q = blk_mq_init_allocated_queue(md->tag_set, md->queue);
 	if (IS_ERR(q)) {
 		err = PTR_ERR(q);
 		goto out_tag_set;
 	}
-	md->queue = q;
 	dm_init_md_queue(md);
 
 	/* backfill 'mq' sysfs registration normally done in blk_register_queue */
 	blk_mq_register_disk(md->disk);
 
-	if (md_type == DM_TYPE_REQUEST_BASED)
-		init_rq_based_worker_thread(md);
-
 	return 0;
 
 out_tag_set:
-	blk_mq_free_tag_set(&md->tag_set);
+	blk_mq_free_tag_set(md->tag_set);
+out_kfree_tag_set:
+	kfree(md->tag_set);
+
 	return err;
 }
 
@@ -2769,28 +2818,28 @@ static unsigned filter_md_type(unsigned type, struct mapped_device *md)
 /*
  * Setup the DM device's queue based on md's type
  */
-int dm_setup_md_queue(struct mapped_device *md)
+int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
 {
 	int r;
 	unsigned md_type = filter_md_type(dm_get_md_type(md), md);
 
 	switch (md_type) {
 	case DM_TYPE_REQUEST_BASED:
-		r = dm_init_request_based_queue(md);
+		r = dm_old_init_request_queue(md);
 		if (r) {
-			DMWARN("Cannot initialize queue for request-based mapped device");
+			DMERR("Cannot initialize queue for request-based mapped device");
 			return r;
 		}
 		break;
 	case DM_TYPE_MQ_REQUEST_BASED:
-		r = dm_init_request_based_blk_mq_queue(md);
+		r = dm_mq_init_request_queue(md, dm_table_get_immutable_target(t));
 		if (r) {
-			DMWARN("Cannot initialize queue for request-based blk-mq mapped device");
+			DMERR("Cannot initialize queue for request-based dm-mq mapped device");
 			return r;
 		}
 		break;
 	case DM_TYPE_BIO_BASED:
-		dm_init_old_md_queue(md);
+		dm_init_normal_md_queue(md);
 		blk_queue_make_request(md->queue, dm_make_request);
 		/*
 		 * DM handles splitting bios as needed.  Free the bio_split bioset
@@ -3133,7 +3182,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
 	 * dm defers requests to md->wq from md->queue.
 	 */
 	if (dm_request_based(md)) {
-		stop_queue(md->queue);
+		dm_stop_queue(md->queue);
 		if (md->kworker_task)
 			flush_kthread_worker(&md->kworker);
 	}
@@ -3157,7 +3206,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
 		dm_queue_flush(md);
 
 		if (dm_request_based(md))
-			start_queue(md->queue);
+			dm_start_queue(md->queue);
 
 		unlock_fs(md);
 		dm_table_presuspend_undo_targets(map);
@@ -3236,7 +3285,7 @@ static int __dm_resume(struct mapped_device *md, struct dm_table *map)
 	 * Request-based dm is queueing the deferred I/Os in its request_queue.
 	 */
 	if (dm_request_based(md))
-		start_queue(md->queue);
+		dm_start_queue(md->queue);
 
 	unlock_fs(md);
 
@@ -3482,9 +3531,9 @@ 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,
-					    unsigned integrity, unsigned per_bio_data_size)
+					    unsigned integrity, unsigned per_io_data_size)
 {
-	struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL);
+	struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
 	struct kmem_cache *cachep = NULL;
 	unsigned int pool_size = 0;
 	unsigned int front_pad;
@@ -3498,7 +3547,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned t
 	case DM_TYPE_BIO_BASED:
 		cachep = _io_cache;
 		pool_size = dm_get_reserved_bio_based_ios();
-		front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
+		front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
 		break;
 	case DM_TYPE_REQUEST_BASED:
 		cachep = _rq_tio_cache;
@@ -3511,8 +3560,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned t
 		if (!pool_size)
 			pool_size = dm_get_reserved_rq_based_ios();
 		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
-		/* per_bio_data_size is not used. See __bind_mempools(). */
-		WARN_ON(per_bio_data_size != 0);
+		/* per_io_data_size is used for blk-mq pdu at queue allocation */
 		break;
 	default:
 		BUG();
@@ -3554,15 +3602,14 @@ void dm_free_md_mempools(struct dm_md_mempools *pools)
 }
 
 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
-		u32 flags)
+			  u32 flags)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
 	const struct pr_ops *ops;
-	struct dm_target *tgt;
 	fmode_t mode;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -3572,20 +3619,19 @@ static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
 	else
 		r = -EOPNOTSUPP;
 
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
-		u32 flags)
+			 u32 flags)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
 	const struct pr_ops *ops;
-	struct dm_target *tgt;
 	fmode_t mode;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -3595,7 +3641,7 @@ static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
 	else
 		r = -EOPNOTSUPP;
 
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
@@ -3603,11 +3649,10 @@ static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
 	const struct pr_ops *ops;
-	struct dm_target *tgt;
 	fmode_t mode;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -3617,20 +3662,19 @@ static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 	else
 		r = -EOPNOTSUPP;
 
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
-		enum pr_type type, bool abort)
+			 enum pr_type type, bool abort)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
 	const struct pr_ops *ops;
-	struct dm_target *tgt;
 	fmode_t mode;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -3640,7 +3684,7 @@ static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
 	else
 		r = -EOPNOTSUPP;
 
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
@@ -3648,11 +3692,10 @@ static int dm_pr_clear(struct block_device *bdev, u64 key)
 {
 	struct mapped_device *md = bdev->bd_disk->private_data;
 	const struct pr_ops *ops;
-	struct dm_target *tgt;
 	fmode_t mode;
-	int srcu_idx, r;
+	int r;
 
-	r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+	r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
 	if (r < 0)
 		return r;
 
@@ -3662,7 +3705,7 @@ static int dm_pr_clear(struct block_device *bdev, u64 key)
 	else
 		r = -EOPNOTSUPP;
 
-	dm_put_live_table(md, srcu_idx);
+	bdput(bdev);
 	return r;
 }
 
@@ -3701,6 +3744,15 @@ MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools"
 module_param(use_blk_mq, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(use_blk_mq, "Use block multiqueue for request-based DM devices");
 
+module_param(dm_mq_nr_hw_queues, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dm_mq_nr_hw_queues, "Number of hardware queues for request-based dm-mq devices");
+
+module_param(dm_mq_queue_depth, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dm_mq_queue_depth, "Queue depth for request-based dm-mq devices");
+
+module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
+
 MODULE_DESCRIPTION(DM_NAME " driver");
 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
 MODULE_LICENSE("GPL");