Merge tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull dm update from Alasdair G Kergon:
 "Miscellaneous device-mapper fixes, cleanups and performance
  improvements.

  Of particular note:
   - Disable broken WRITE SAME support in all targets except linear and
     striped.  Use it when kcopyd is zeroing blocks.
   - Remove several mempools from targets by moving the data into the
     bio's new front_pad area(which dm calls 'per_bio_data').
   - Fix a race in thin provisioning if discards are misused.
   - Prevent userspace from interfering with the ioctl parameters and
     use kmalloc for the data buffer if it's small instead of vmalloc.
   - Throttle some annoying error messages when I/O fails."

* tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (36 commits)
  dm stripe: add WRITE SAME support
  dm: remove map_info
  dm snapshot: do not use map_context
  dm thin: dont use map_context
  dm raid1: dont use map_context
  dm flakey: dont use map_context
  dm raid1: rename read_record to bio_record
  dm: move target request nr to dm_target_io
  dm snapshot: use per_bio_data
  dm verity: use per_bio_data
  dm raid1: use per_bio_data
  dm: introduce per_bio_data
  dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
  dm linear: add WRITE SAME support
  dm: add WRITE SAME support
  dm: prepare to support WRITE SAME
  dm ioctl: use kmalloc if possible
  dm ioctl: remove PF_MEMALLOC
  dm persistent data: improve improve space map block alloc failure message
  dm thin: use DMERR_LIMIT for errors
  ...

28 files changed, 473 insertions, 433 deletions

diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index e4e841567459..aefb78e3cbf9 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -208,31 +208,6 @@ void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios)
 EXPORT_SYMBOL_GPL(dm_cell_release);
 
 /*
- * There are a couple of places where we put a bio into a cell briefly
- * before taking it out again.  In these situations we know that no other
- * bio may be in the cell.  This function releases the cell, and also does
- * a sanity check.
- */
-static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
-	BUG_ON(cell->holder != bio);
-	BUG_ON(!bio_list_empty(&cell->bios));
-
-	__cell_release(cell, NULL);
-}
-
-void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio)
-{
-	unsigned long flags;
-	struct dm_bio_prison *prison = cell->prison;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	__cell_release_singleton(cell, bio);
-	spin_unlock_irqrestore(&prison->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_cell_release_singleton);
-
-/*
  * Sometimes we don't want the holder, just the additional bios.
  */
 static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates)
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h
index 4e0ac376700a..53d1a7a84e2f 100644
--- a/drivers/md/dm-bio-prison.h
+++ b/drivers/md/dm-bio-prison.h
@@ -44,7 +44,6 @@ int dm_bio_detain(struct dm_bio_prison *prison, struct dm_cell_key *key,
 		  struct bio *inmate, struct dm_bio_prison_cell **ref);
 
 void dm_cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios);
-void dm_cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio); // FIXME: bio arg not needed
 void dm_cell_release_no_holder(struct dm_bio_prison_cell *cell, struct bio_list *inmates);
 void dm_cell_error(struct dm_bio_prison_cell *cell);
 
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index bbf459bca61d..f7369f9d8595 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1689,8 +1689,7 @@ bad:
 	return ret;
 }
 
-static int crypt_map(struct dm_target *ti, struct bio *bio,
-		     union map_info *map_context)
+static int crypt_map(struct dm_target *ti, struct bio *bio)
 {
 	struct dm_crypt_io *io;
 	struct crypt_config *cc = ti->private;
@@ -1846,7 +1845,7 @@ static int crypt_iterate_devices(struct dm_target *ti,
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version = {1, 11, 0},
+	.version = {1, 12, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index f53846f9ab50..cc1bd048acb2 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -274,8 +274,7 @@ static void delay_resume(struct dm_target *ti)
 	atomic_set(&dc->may_delay, 1);
 }
 
-static int delay_map(struct dm_target *ti, struct bio *bio,
-		     union map_info *map_context)
+static int delay_map(struct dm_target *ti, struct bio *bio)
 {
 	struct delay_c *dc = ti->private;
 
@@ -338,7 +337,7 @@ out:
 
 static struct target_type delay_target = {
 	.name	     = "delay",
-	.version     = {1, 1, 0},
+	.version     = {1, 2, 0},
 	.module      = THIS_MODULE,
 	.ctr	     = delay_ctr,
 	.dtr	     = delay_dtr,
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index cc15543a6ad7..9721f2ffb1a2 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -39,6 +39,10 @@ enum feature_flag_bits {
 	DROP_WRITES
 };
 
+struct per_bio_data {
+	bool bio_submitted;
+};
+
 static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
 			  struct dm_target *ti)
 {
@@ -214,6 +218,7 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	ti->num_flush_requests = 1;
 	ti->num_discard_requests = 1;
+	ti->per_bio_data_size = sizeof(struct per_bio_data);
 	ti->private = fc;
 	return 0;
 
@@ -265,11 +270,12 @@ static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
 	}
 }
 
-static int flakey_map(struct dm_target *ti, struct bio *bio,
-		      union map_info *map_context)
+static int flakey_map(struct dm_target *ti, struct bio *bio)
 {
 	struct flakey_c *fc = ti->private;
 	unsigned elapsed;
+	struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
+	pb->bio_submitted = false;
 
 	/* Are we alive ? */
 	elapsed = (jiffies - fc->start_time) / HZ;
@@ -277,7 +283,7 @@ static int flakey_map(struct dm_target *ti, struct bio *bio,
 		/*
 		 * Flag this bio as submitted while down.
 		 */
-		map_context->ll = 1;
+		pb->bio_submitted = true;
 
 		/*
 		 * Map reads as normal.
@@ -314,17 +320,16 @@ map_bio:
 	return DM_MAPIO_REMAPPED;
 }
 
-static int flakey_end_io(struct dm_target *ti, struct bio *bio,
-			 int error, union map_info *map_context)
+static int flakey_end_io(struct dm_target *ti, struct bio *bio, int error)
 {
 	struct flakey_c *fc = ti->private;
-	unsigned bio_submitted_while_down = map_context->ll;
+	struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
 
 	/*
 	 * Corrupt successful READs while in down state.
 	 * If flags were specified, only corrupt those that match.
 	 */
-	if (fc->corrupt_bio_byte && !error && bio_submitted_while_down &&
+	if (fc->corrupt_bio_byte && !error && pb->bio_submitted &&
 	    (bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == READ) &&
 	    all_corrupt_bio_flags_match(bio, fc))
 		corrupt_bio_data(bio, fc);
@@ -406,7 +411,7 @@ static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_
 
 static struct target_type flakey_target = {
 	.name   = "flakey",
-	.version = {1, 2, 0},
+	.version = {1, 3, 0},
 	.module = THIS_MODULE,
 	.ctr    = flakey_ctr,
 	.dtr    = flakey_dtr,
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 1c46f97d6664..ea49834377c8 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -287,7 +287,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
 	unsigned num_bvecs;
 	sector_t remaining = where->count;
 	struct request_queue *q = bdev_get_queue(where->bdev);
-	sector_t discard_sectors;
+	unsigned short logical_block_size = queue_logical_block_size(q);
+	sector_t num_sectors;
 
 	/*
 	 * where->count may be zero if rw holds a flush and we need to
@@ -297,7 +298,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
 		/*
 		 * Allocate a suitably sized-bio.
 		 */
-		if (rw & REQ_DISCARD)
+		if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME))
 			num_bvecs = 1;
 		else
 			num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
@@ -310,9 +311,21 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
 		store_io_and_region_in_bio(bio, io, region);
 
 		if (rw & REQ_DISCARD) {
-			discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
-			bio->bi_size = discard_sectors << SECTOR_SHIFT;
-			remaining -= discard_sectors;
+			num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
+			bio->bi_size = num_sectors << SECTOR_SHIFT;
+			remaining -= num_sectors;
+		} else if (rw & REQ_WRITE_SAME) {
+			/*
+			 * WRITE SAME only uses a single page.
+			 */
+			dp->get_page(dp, &page, &len, &offset);
+			bio_add_page(bio, page, logical_block_size, offset);
+			num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining);
+			bio->bi_size = num_sectors << SECTOR_SHIFT;
+
+			offset = 0;
+			remaining -= num_sectors;
+			dp->next_page(dp);
 		} else while (remaining) {
 			/*
 			 * Try and add as many pages as possible.
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index afd95986d099..0666b5d14b88 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1543,7 +1543,21 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
 	return r;
 }
 
-static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
+#define DM_PARAMS_VMALLOC	0x0001	/* Params alloced with vmalloc not kmalloc */
+#define DM_WIPE_BUFFER		0x0010	/* Wipe input buffer before returning from ioctl */
+
+static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
+{
+	if (param_flags & DM_WIPE_BUFFER)
+		memset(param, 0, param_size);
+
+	if (param_flags & DM_PARAMS_VMALLOC)
+		vfree(param);
+	else
+		kfree(param);
+}
+
+static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param, int *param_flags)
 {
 	struct dm_ioctl tmp, *dmi;
 	int secure_data;
@@ -1556,7 +1570,21 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 
 	secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
 
-	dmi = vmalloc(tmp.data_size);
+	*param_flags = secure_data ? DM_WIPE_BUFFER : 0;
+
+	/*
+	 * Try to avoid low memory issues when a device is suspended.
+	 * Use kmalloc() rather than vmalloc() when we can.
+	 */
+	dmi = NULL;
+	if (tmp.data_size <= KMALLOC_MAX_SIZE)
+		dmi = kmalloc(tmp.data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
+
+	if (!dmi) {
+		dmi = __vmalloc(tmp.data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL);
+		*param_flags |= DM_PARAMS_VMALLOC;
+	}
+
 	if (!dmi) {
 		if (secure_data && clear_user(user, tmp.data_size))
 			return -EFAULT;
@@ -1566,6 +1594,14 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 	if (copy_from_user(dmi, user, tmp.data_size))
 		goto bad;
 
+	/*
+	 * Abort if something changed the ioctl data while it was being copied.
+	 */
+	if (dmi->data_size != tmp.data_size) {
+		DMERR("rejecting ioctl: data size modified while processing parameters");
+		goto bad;
+	}
+
 	/* Wipe the user buffer so we do not return it to userspace */
 	if (secure_data && clear_user(user, tmp.data_size))
 		goto bad;
@@ -1574,9 +1610,8 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 	return 0;
 
 bad:
-	if (secure_data)
-		memset(dmi, 0, tmp.data_size);
-	vfree(dmi);
+	free_params(dmi, tmp.data_size, *param_flags);
+
 	return -EFAULT;
 }
 
@@ -1613,7 +1648,7 @@ static int validate_params(uint cmd, struct dm_ioctl *param)
 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 {
 	int r = 0;
-	int wipe_buffer;
+	int param_flags;
 	unsigned int cmd;
 	struct dm_ioctl *uninitialized_var(param);
 	ioctl_fn fn = NULL;
@@ -1649,24 +1684,14 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 	}
 
 	/*
-	 * Trying to avoid low memory issues when a device is
-	 * suspended.
-	 */
-	current->flags |= PF_MEMALLOC;
-
-	/*
 	 * Copy the parameters into kernel space.
 	 */
-	r = copy_params(user, &param);
-
-	current->flags &= ~PF_MEMALLOC;
+	r = copy_params(user, &param, &param_flags);
 
 	if (r)
 		return r;
 
 	input_param_size = param->data_size;
-	wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
-
 	r = validate_params(cmd, param);
 	if (r)
 		goto out;
@@ -1681,10 +1706,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
 		r = -EFAULT;
 
 out:
-	if (wipe_buffer)
-		memset(param, 0, input_param_size);
-
-	vfree(param);
+	free_params(param, input_param_size, param_flags);
 	return r;
 }
 
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index bed444c93d8d..68c02673263b 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -349,7 +349,7 @@ static void complete_io(unsigned long error, void *context)
 	struct dm_kcopyd_client *kc = job->kc;
 
 	if (error) {
-		if (job->rw == WRITE)
+		if (job->rw & WRITE)
 			job->write_err |= error;
 		else
 			job->read_err = 1;
@@ -361,7 +361,7 @@ static void complete_io(unsigned long error, void *context)
 		}
 	}
 
-	if (job->rw == WRITE)
+	if (job->rw & WRITE)
 		push(&kc->complete_jobs, job);
 
 	else {
@@ -432,7 +432,7 @@ static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc,
 
 		if (r < 0) {
 			/* error this rogue job */
-			if (job->rw == WRITE)
+			if (job->rw & WRITE)
 				job->write_err = (unsigned long) -1L;
 			else
 				job->read_err = 1;
@@ -585,6 +585,7 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
 		   unsigned int flags, dm_kcopyd_notify_fn fn, void *context)
 {
 	struct kcopyd_job *job;
+	int i;
 
 	/*
 	 * Allocate an array of jobs consisting of one master job
@@ -611,7 +612,16 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
 		memset(&job->source, 0, sizeof job->source);
 		job->source.count = job->dests[0].count;
 		job->pages = &zero_page_list;
-		job->rw = WRITE;
+
+		/*
+		 * Use WRITE SAME to optimize zeroing if all dests support it.
+		 */
+		job->rw = WRITE | REQ_WRITE_SAME;
+		for (i = 0; i < job->num_dests; i++)
+			if (!bdev_write_same(job->dests[i].bdev)) {
+				job->rw = WRITE;
+				break;
+			}
 	}
 
 	job->fn = fn;
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 1bf19a93eef0..328cad5617ab 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -55,6 +55,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	ti->num_flush_requests = 1;
 	ti->num_discard_requests = 1;
+	ti->num_write_same_requests = 1;
 	ti->private = lc;
 	return 0;
 
@@ -87,8 +88,7 @@ static void linear_map_bio(struct dm_target *ti, struct bio *bio)
 		bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
 }
 
-static int linear_map(struct dm_target *ti, struct bio *bio,
-		      union map_info *map_context)
+static int linear_map(struct dm_target *ti, struct bio *bio)
 {
 	linear_map_bio(ti, bio);
 
@@ -155,7 +155,7 @@ static int linear_iterate_devices(struct dm_target *ti,
 
 static struct target_type linear_target = {
 	.name   = "linear",
-	.version = {1, 1, 0},
+	.version = {1, 2, 0},
 	.module = THIS_MODULE,
 	.ctr    = linear_ctr,
 	.dtr    = linear_dtr,
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 45d94a7e7f6d..3d8984edeff7 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -295,9 +295,11 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 		 * Choose a reasonable default.  All figures in sectors.
 		 */
 		if (min_region_size > (1 << 13)) {
+			/* If not a power of 2, make it the next power of 2 */
+			if (min_region_size & (min_region_size - 1))
+				region_size = 1 << fls(region_size);
 			DMINFO("Choosing default region size of %lu sectors",
 			       region_size);
-			region_size = min_region_size;
 		} else {
 			DMINFO("Choosing default region size of 4MiB");
 			region_size = 1 << 13; /* sectors */
@@ -1216,7 +1218,7 @@ static void raid_dtr(struct dm_target *ti)
 	context_free(rs);
 }
 
-static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
+static int raid_map(struct dm_target *ti, struct bio *bio)
 {
 	struct raid_set *rs = ti->private;
 	struct mddev *mddev = &rs->md;
@@ -1430,7 +1432,7 @@ static void raid_resume(struct dm_target *ti)
 
 static struct target_type raid_target = {
 	.name = "raid",
-	.version = {1, 3, 1},
+	.version = {1, 4, 0},
 	.module = THIS_MODULE,
 	.ctr = raid_ctr,
 	.dtr = raid_dtr,
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index fd61f98ee1f6..fa519185ebba 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -61,7 +61,6 @@ struct mirror_set {
 	struct dm_region_hash *rh;
 	struct dm_kcopyd_client *kcopyd_client;
 	struct dm_io_client *io_client;
-	mempool_t *read_record_pool;
 
 	/* recovery */
 	region_t nr_regions;
@@ -139,14 +138,13 @@ static void dispatch_bios(void *context, struct bio_list *bio_list)
 		queue_bio(ms, bio, WRITE);
 }
 
-#define MIN_READ_RECORDS 20
-struct dm_raid1_read_record {
+struct dm_raid1_bio_record {
 	struct mirror *m;
+	/* if details->bi_bdev == NULL, details were not saved */
 	struct dm_bio_details details;
+	region_t write_region;
 };
 
-static struct kmem_cache *_dm_raid1_read_record_cache;
-
 /*
  * Every mirror should look like this one.
  */
@@ -876,19 +874,9 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
 	atomic_set(&ms->suspend, 0);
 	atomic_set(&ms->default_mirror, DEFAULT_MIRROR);
 
-	ms->read_record_pool = mempool_create_slab_pool(MIN_READ_RECORDS,
-						_dm_raid1_read_record_cache);
-
-	if (!ms->read_record_pool) {
-		ti->error = "Error creating mirror read_record_pool";
-		kfree(ms);
-		return NULL;
-	}
-
 	ms->io_client = dm_io_client_create();
 	if (IS_ERR(ms->io_client)) {
 		ti->error = "Error creating dm_io client";
-		mempool_destroy(ms->read_record_pool);
 		kfree(ms);
  		return NULL;
 	}
@@ -900,7 +888,6 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
 	if (IS_ERR(ms->rh)) {
 		ti->error = "Error creating dirty region hash";
 		dm_io_client_destroy(ms->io_client);
-		mempool_destroy(ms->read_record_pool);
 		kfree(ms);
 		return NULL;
 	}
@@ -916,7 +903,6 @@ static void free_context(struct mirror_set *ms, struct dm_target *ti,
 
 	dm_io_client_destroy(ms->io_client);
 	dm_region_hash_destroy(ms->rh);
-	mempool_destroy(ms->read_record_pool);
 	kfree(ms);
 }
 
@@ -1088,6 +1074,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	ti->num_flush_requests = 1;
 	ti->num_discard_requests = 1;
+	ti->per_bio_data_size = sizeof(struct dm_raid1_bio_record);
 	ti->discard_zeroes_data_unsupported = true;
 
 	ms->kmirrord_wq = alloc_workqueue("kmirrord",
@@ -1155,18 +1142,20 @@ static void mirror_dtr(struct dm_target *ti)
 /*
  * Mirror mapping function
  */
-static int mirror_map(struct dm_target *ti, struct bio *bio,
-		      union map_info *map_context)
+static int mirror_map(struct dm_target *ti, struct bio *bio)
 {
 	int r, rw = bio_rw(bio);
 	struct mirror *m;
 	struct mirror_set *ms = ti->private;
-	struct dm_raid1_read_record *read_record = NULL;
 	struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+	struct dm_raid1_bio_record *bio_record =
+	  dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
+
+	bio_record->details.bi_bdev = NULL;
 
 	if (rw == WRITE) {
 		/* Save region for mirror_end_io() handler */
-		map_context->ll = dm_rh_bio_to_region(ms->rh, bio);
+		bio_record->write_region = dm_rh_bio_to_region(ms->rh, bio);
 		queue_bio(ms, bio, rw);
 		return DM_MAPIO_SUBMITTED;
 	}
@@ -1194,33 +1183,29 @@ static int mirror_map(struct dm_target *ti, struct bio *bio,
 	if (unlikely(!m))
 		return -EIO;
 
-	read_record = mempool_alloc(ms->read_record_pool, GFP_NOIO);
-	if (likely(read_record)) {
-		dm_bio_record(&read_record->details, bio);
-		map_context->ptr = read_record;
-		read_record->m = m;
-	}
+	dm_bio_record(&bio_record->details, bio);
+	bio_record->m = m;
 
 	map_bio(m, bio);
 
 	return DM_MAPIO_REMAPPED;
 }
 
-static int mirror_end_io(struct dm_target *ti, struct bio *bio,
-			 int error, union map_info *map_context)
+static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
 {
 	int rw = bio_rw(bio);
 	struct mirror_set *ms = (struct mirror_set *) ti->private;
 	struct mirror *m = NULL;
 	struct dm_bio_details *bd = NULL;
-	struct dm_raid1_read_record *read_record = map_context->ptr;
+	struct dm_raid1_bio_record *bio_record =
+	  dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
 
 	/*
 	 * We need to dec pending if this was a write.
 	 */
 	if (rw == WRITE) {
 		if (!(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD)))
-			dm_rh_dec(ms->rh, map_context->ll);
+			dm_rh_dec(ms->rh, bio_record->write_region);
 		return error;
 	}
 
@@ -1231,7 +1216,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 		goto out;
 
 	if (unlikely(error)) {
-		if (!read_record) {
+		if (!bio_record->details.bi_bdev) {
 			/*
 			 * There wasn't enough memory to record necessary
 			 * information for a retry or there was no other
@@ -1241,7 +1226,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 			return -EIO;
 		}
 
-		m = read_record->m;
+		m = bio_record->m;
 
 		DMERR("Mirror read failed from %s. Trying alternative device.",
 		      m->dev->name);
@@ -1253,22 +1238,18 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 		 * mirror.
 		 */
 		if (default_ok(m) || mirror_available(ms, bio)) {
-			bd = &read_record->details;
+			bd = &bio_record->details;
 
 			dm_bio_restore(bd, bio);
-			mempool_free(read_record, ms->read_record_pool);
-			map_context->ptr = NULL;
+			bio_record->details.bi_bdev = NULL;
 			queue_bio(ms, bio, rw);
-			return 1;
+			return DM_ENDIO_INCOMPLETE;
 		}
 		DMERR("All replicated volumes dead, failing I/O");
 	}
 
 out:
-	if (read_record) {
-		mempool_free(read_record, ms->read_record_pool);
-		map_context->ptr = NULL;
-	}
+	bio_record->details.bi_bdev = NULL;
 
 	return error;
 }
@@ -1422,7 +1403,7 @@ static int mirror_iterate_devices(struct dm_target *ti,
 
 static struct target_type mirror_target = {
 	.name	 = "mirror",
-	.version = {1, 12, 1},
+	.version = {1, 13, 1},
 	.module	 = THIS_MODULE,
 	.ctr	 = mirror_ctr,
 	.dtr	 = mirror_dtr,
@@ -1439,13 +1420,6 @@ static int __init dm_mirror_init(void)
 {
 	int r;
 
-	_dm_raid1_read_record_cache = KMEM_CACHE(dm_raid1_read_record, 0);
-	if (!_dm_raid1_read_record_cache) {
-		DMERR("Can't allocate dm_raid1_read_record cache");
-		r = -ENOMEM;
-		goto bad_cache;
-	}
-
 	r = dm_register_target(&mirror_target);
 	if (r < 0) {
 		DMERR("Failed to register mirror target");
@@ -1455,15 +1429,12 @@ static int __init dm_mirror_init(void)
 	return 0;
 
 bad_target:
-	kmem_cache_destroy(_dm_raid1_read_record_cache);
-bad_cache:
 	return r;
 }
 
 static void __exit dm_mirror_exit(void)
 {
 	dm_unregister_target(&mirror_target);
-	kmem_cache_destroy(_dm_raid1_read_record_cache);
 }
 
 /* Module hooks */
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index a143921feaf6..59fc18ae52c2 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -79,7 +79,6 @@ struct dm_snapshot {
 
 	/* Chunks with outstanding reads */
 	spinlock_t tracked_chunk_lock;
-	mempool_t *tracked_chunk_pool;
 	struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
 
 	/* The on disk metadata handler */
@@ -191,35 +190,38 @@ struct dm_snap_tracked_chunk {
 	chunk_t chunk;
 };
 
-static struct kmem_cache *tracked_chunk_cache;
+static void init_tracked_chunk(struct bio *bio)
+{
+	struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
+	INIT_HLIST_NODE(&c->node);
+}
 
-static struct dm_snap_tracked_chunk *track_chunk(struct dm_snapshot *s,
-						 chunk_t chunk)
+static bool is_bio_tracked(struct bio *bio)
 {
-	struct dm_snap_tracked_chunk *c = mempool_alloc(s->tracked_chunk_pool,
-							GFP_NOIO);
-	unsigned long flags;
+	struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
+	return !hlist_unhashed(&c->node);
+}
+
+static void track_chunk(struct dm_snapshot *s, struct bio *bio, chunk_t chunk)
+{
+	struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
 
 	c->chunk = chunk;
 
-	spin_lock_irqsave(&s->tracked_chunk_lock, flags);
+	spin_lock_irq(&s->tracked_chunk_lock);
 	hlist_add_head(&c->node,
 		       &s->tracked_chunk_hash[DM_TRACKED_CHUNK_HASH(chunk)]);
-	spin_unlock_irqrestore(&s->tracked_chunk_lock, flags);
-
-	return c;
+	spin_unlock_irq(&s->tracked_chunk_lock);
 }
 
-static void stop_tracking_chunk(struct dm_snapshot *s,
-				struct dm_snap_tracked_chunk *c)
+static void stop_tracking_chunk(struct dm_snapshot *s, struct bio *bio)
 {
+	struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
 	unsigned long flags;
 
 	spin_lock_irqsave(&s->tracked_chunk_lock, flags);
 	hlist_del(&c->node);
 	spin_unlock_irqrestore(&s->tracked_chunk_lock, flags);
-
-	mempool_free(c, s->tracked_chunk_pool);
 }
 
 static int __chunk_is_tracked(struct dm_snapshot *s, chunk_t chunk)
@@ -1120,14 +1122,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_pending_pool;
 	}
 
-	s->tracked_chunk_pool = mempool_create_slab_pool(MIN_IOS,
-							 tracked_chunk_cache);
-	if (!s->tracked_chunk_pool) {
-		ti->error = "Could not allocate tracked_chunk mempool for "
-			    "tracking reads";
-		goto bad_tracked_chunk_pool;
-	}
-
 	for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)
 		INIT_HLIST_HEAD(&s->tracked_chunk_hash[i]);
 
@@ -1135,6 +1129,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	ti->private = s;
 	ti->num_flush_requests = num_flush_requests;
+	ti->per_bio_data_size = sizeof(struct dm_snap_tracked_chunk);
 
 	/* Add snapshot to the list of snapshots for this origin */
 	/* Exceptions aren't triggered till snapshot_resume() is called */
@@ -1183,9 +1178,6 @@ bad_read_metadata:
 	unregister_snapshot(s);
 
 bad_load_and_register:
-	mempool_destroy(s->tracked_chunk_pool);
-
-bad_tracked_chunk_pool:
 	mempool_destroy(s->pending_pool);
 
 bad_pending_pool:
@@ -1290,8 +1282,6 @@ static void snapshot_dtr(struct dm_target *ti)
 		BUG_ON(!hlist_empty(&s->tracked_chunk_hash[i]));
 #endif
 
-	mempool_destroy(s->tracked_chunk_pool);
-
 	__free_exceptions(s);
 
 	mempool_destroy(s->pending_pool);
@@ -1577,8 +1567,7 @@ static void remap_exception(struct dm_snapshot *s, struct dm_exception *e,
 					  s->store->chunk_mask);
 }
 
-static int snapshot_map(struct dm_target *ti, struct bio *bio,
-			union map_info *map_context)
+static int snapshot_map(struct dm_target *ti, struct bio *bio)
 {
 	struct dm_exception *e;
 	struct dm_snapshot *s = ti->private;
@@ -1586,6 +1575,8 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
 	chunk_t chunk;
 	struct dm_snap_pending_exception *pe = NULL;
 
+	init_tracked_chunk(bio);
+
 	if (bio->bi_rw & REQ_FLUSH) {
 		bio->bi_bdev = s->cow->bdev;
 		return DM_MAPIO_REMAPPED;
@@ -1670,7 +1661,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
 		}