Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm raid1: fix deadlock when suspending failed device
  dm: eliminate some holes data structures
  dm ioctl: introduce flag indicating uevent was generated
  dm: free dm_io before bio_endio not after
  dm table: remove unused dm_get_device range parameters
  dm ioctl: only issue uevent on resume if state changed
  dm raid1: always return error if all legs fail
  dm mpath: refactor pg_init
  dm mpath: wait for pg_init completion when suspending
  dm mpath: hold io until all pg_inits completed
  dm mpath: avoid storing private suspended state
  dm: document when snapshot has finished merging
  dm table: remove dm_get from dm_table_get_md
  dm mpath: skip activate_path for failed paths
  dm mpath: pass struct pgpath to pg init done

17 files changed, 212 insertions, 140 deletions

diff --git a/Documentation/device-mapper/snapshot.txt b/Documentation/device-mapper/snapshot.txt
index e3a77b21513..0d5bc46dc16 100644
--- a/Documentation/device-mapper/snapshot.txt
+++ b/Documentation/device-mapper/snapshot.txt
@@ -122,3 +122,47 @@ volumeGroup-base: 0 2097152 snapshot-merge 254:11 254:12 P 16
 brw-------  1 root root 254, 11 29 ago 18:15 /dev/mapper/volumeGroup-base-real
 brw-------  1 root root 254, 12 29 ago 18:16 /dev/mapper/volumeGroup-base-cow
 brw-------  1 root root 254, 10 29 ago 18:16 /dev/mapper/volumeGroup-base
+
+
+How to determine when a merging is complete
+===========================================
+The snapshot-merge and snapshot status lines end with:
+  <sectors_allocated>/<total_sectors> <metadata_sectors>
+
+Both <sectors_allocated> and <total_sectors> include both data and metadata.
+During merging, the number of sectors allocated gets smaller and
+smaller.  Merging has finished when the number of sectors holding data
+is zero, in other words <sectors_allocated> == <metadata_sectors>.
+
+Here is a practical example (using a hybrid of lvm and dmsetup commands):
+
+# lvs
+  LV      VG          Attr   LSize Origin  Snap%  Move Log Copy%  Convert
+  base    volumeGroup owi-a- 4.00g
+  snap    volumeGroup swi-a- 1.00g base  18.97
+
+# dmsetup status volumeGroup-snap
+0 8388608 snapshot 397896/2097152 1560
+                                  ^^^^ metadata sectors
+
+# lvconvert --merge -b volumeGroup/snap
+  Merging of volume snap started.
+
+# lvs volumeGroup/snap
+  LV      VG          Attr   LSize Origin  Snap%  Move Log Copy%  Convert
+  base    volumeGroup Owi-a- 4.00g          17.23
+
+# dmsetup status volumeGroup-base
+0 8388608 snapshot-merge 281688/2097152 1104
+
+# dmsetup status volumeGroup-base
+0 8388608 snapshot-merge 180480/2097152 712
+
+# dmsetup status volumeGroup-base
+0 8388608 snapshot-merge 16/2097152 16
+
+Merging has finished.
+
+# lvs
+  LV      VG          Attr   LSize Origin  Snap%  Move Log Copy%  Convert
+  base    volumeGroup owi-a- 4.00g
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index a93637223c8..3bdbb611570 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1160,8 +1160,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 	cc->start = tmpll;
 
-	if (dm_get_device(ti, argv[3], cc->start, ti->len,
-			  dm_table_get_mode(ti->table), &cc->dev)) {
+	if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
 		ti->error = "Device lookup failed";
 		goto bad_device;
 	}
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index ebe7381f47c..852052880d7 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -156,8 +156,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad;
 	}
 
-	if (dm_get_device(ti, argv[0], dc->start_read, ti->len,
-			  dm_table_get_mode(ti->table), &dc->dev_read)) {
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+			  &dc->dev_read)) {
 		ti->error = "Device lookup failed";
 		goto bad;
 	}
@@ -177,8 +177,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad_dev_read;
 	}
 
-	if (dm_get_device(ti, argv[3], dc->start_write, ti->len,
-			  dm_table_get_mode(ti->table), &dc->dev_write)) {
+	if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
+			  &dc->dev_write)) {
 		ti->error = "Write device lookup failed";
 		goto bad_dev_read;
 	}
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 1d669322b27..d7500e1c26f 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -285,7 +285,8 @@ retry:
 	up_write(&_hash_lock);
 }
 
-static int dm_hash_rename(uint32_t cookie, const char *old, const char *new)
+static int dm_hash_rename(uint32_t cookie, uint32_t *flags, const char *old,
+			  const char *new)
 {
 	char *new_name, *old_name;
 	struct hash_cell *hc;
@@ -344,7 +345,8 @@ static int dm_hash_rename(uint32_t cookie, const char *old, const char *new)
 		dm_table_put(table);
 	}
 
-	dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie);
+	if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie))
+		*flags |= DM_UEVENT_GENERATED_FLAG;
 
 	dm_put(hc->md);
 	up_write(&_hash_lock);
@@ -736,10 +738,10 @@ static int dev_remove(struct dm_ioctl *param, size_t param_size)
 	__hash_remove(hc);
 	up_write(&_hash_lock);
 
-	dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr);
+	if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
+		param->flags |= DM_UEVENT_GENERATED_FLAG;
 
 	dm_put(md);
-	param->data_size = 0;
 	return 0;
 }
 
@@ -773,7 +775,9 @@ static int dev_rename(struct dm_ioctl *param, size_t param_size)
 		return r;
 
 	param->data_size = 0;
-	return dm_hash_rename(param->event_nr, param->name, new_name);
+
+	return dm_hash_rename(param->event_nr, &param->flags, param->name,
+			      new_name);
 }
 
 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
@@ -897,16 +901,17 @@ static int do_resume(struct dm_ioctl *param)
 			set_disk_ro(dm_disk(md), 1);
 	}
 
-	if (dm_suspended_md(md))
+	if (dm_suspended_md(md)) {
 		r = dm_resume(md);
+		if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
+			param->flags |= DM_UEVENT_GENERATED_FLAG;
+	}
 
 	if (old_map)
 		dm_table_destroy(old_map);
 
-	if (!r) {
-		dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr);
+	if (!r)
 		r = __dev_status(md, param);
-	}
 
 	dm_put(md);
 	return r;
@@ -1476,6 +1481,7 @@ static int validate_params(uint cmd, struct dm_ioctl *param)
 {
 	/* Always clear this flag */
 	param->flags &= ~DM_BUFFER_FULL_FLAG;
+	param->flags &= ~DM_UEVENT_GENERATED_FLAG;
 
 	/* Ignores parameters */
 	if (cmd == DM_REMOVE_ALL_CMD ||
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 82f7d6e6b1e..9200dbf2391 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -47,8 +47,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 	lc->start = tmp;
 
-	if (dm_get_device(ti, argv[0], lc->start, ti->len,
-			  dm_table_get_mode(ti->table), &lc->dev)) {
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
 		ti->error = "dm-linear: Device lookup failed";
 		goto bad;
 	}
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 7035582786f..5a08be0222d 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -543,8 +543,7 @@ static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 		return -EINVAL;
 	}
 
-	r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
-			  FMODE_READ | FMODE_WRITE, &dev);
+	r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &dev);
 	if (r)
 		return r;
 
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e81345a1d08..826bce7343b 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -69,6 +69,7 @@ struct multipath {
 	struct list_head priority_groups;
 	unsigned pg_init_required;	/* pg_init needs calling? */
 	unsigned pg_init_in_progress;	/* Only one pg_init allowed at once */
+	wait_queue_head_t pg_init_wait;	/* Wait for pg_init completion */
 
 	unsigned nr_valid_paths;	/* Total number of usable paths */
 	struct pgpath *current_pgpath;
@@ -95,8 +96,6 @@ struct multipath {
 	mempool_t *mpio_pool;
 
 	struct mutex work_mutex;
-
-	unsigned suspended;	/* Don't create new I/O internally when set. */
 };
 
 /*
@@ -202,6 +201,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
 		m->queue_io = 1;
 		INIT_WORK(&m->process_queued_ios, process_queued_ios);
 		INIT_WORK(&m->trigger_event, trigger_event);
+		init_waitqueue_head(&m->pg_init_wait);
 		mutex_init(&m->work_mutex);
 		m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
 		if (!m->mpio_pool) {
@@ -235,6 +235,21 @@ static void free_multipath(struct multipath *m)
  * Path selection
  *-----------------------------------------------*/
 
+static void __pg_init_all_paths(struct multipath *m)
+{
+	struct pgpath *pgpath;
+
+	m->pg_init_count++;
+	m->pg_init_required = 0;
+	list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
+		/* Skip failed paths */
+		if (!pgpath->is_active)
+			continue;
+		if (queue_work(kmpath_handlerd, &pgpath->activate_path))
+			m->pg_init_in_progress++;
+	}
+}
+
 static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
 {
 	m->current_pg = pgpath->pg;
@@ -439,7 +454,7 @@ static void process_queued_ios(struct work_struct *work)
 {
 	struct multipath *m =
 		container_of(work, struct multipath, process_queued_ios);
-	struct pgpath *pgpath = NULL, *tmp;
+	struct pgpath *pgpath = NULL;
 	unsigned must_queue = 1;
 	unsigned long flags;
 
@@ -457,14 +472,9 @@ static void process_queued_ios(struct work_struct *work)
 	    (!pgpath && !m->queue_if_no_path))
 		must_queue = 0;
 
-	if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
-		m->pg_init_count++;
-		m->pg_init_required = 0;
-		list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
-			if (queue_work(kmpath_handlerd, &tmp->activate_path))
-				m->pg_init_in_progress++;
-		}
-	}
+	if (m->pg_init_required && !m->pg_init_in_progress && pgpath)
+		__pg_init_all_paths(m);
+
 out:
 	spin_unlock_irqrestore(&m->lock, flags);
 	if (!must_queue)
@@ -597,8 +607,8 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
 	if (!p)
 		return ERR_PTR(-ENOMEM);
 
-	r = dm_get_device(ti, shift(as), ti->begin, ti->len,
-			  dm_table_get_mode(ti->table), &p->path.dev);
+	r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table),
+			  &p->path.dev);
 	if (r) {
 		ti->error = "error getting device";
 		goto bad;
@@ -890,9 +900,34 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
 	return r;
 }
 
-static void flush_multipath_work(void)
+static void multipath_wait_for_pg_init_completion(struct multipath *m)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long flags;
+
+	add_wait_queue(&m->pg_init_wait, &wait);
+
+	while (1) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+
+		spin_lock_irqsave(&m->lock, flags);
+		if (!m->pg_init_in_progress) {
+			spin_unlock_irqrestore(&m->lock, flags);
+			break;
+		}
+		spin_unlock_irqrestore(&m->lock, flags);
+
+		io_schedule();
+	}
+	set_current_state(TASK_RUNNING);
+
+	remove_wait_queue(&m->pg_init_wait, &wait);
+}
+
+static void flush_multipath_work(struct multipath *m)
 {
 	flush_workqueue(kmpath_handlerd);
+	multipath_wait_for_pg_init_completion(m);
 	flush_workqueue(kmultipathd);
 	flush_scheduled_work();
 }
@@ -901,7 +936,7 @@ static void multipath_dtr(struct dm_target *ti)
 {
 	struct multipath *m = ti->private;
 
-	flush_multipath_work();
+	flush_multipath_work(m);
 	free_multipath(m);
 }
 
@@ -1128,8 +1163,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
 
 static void pg_init_done(void *data, int errors)
 {
-	struct dm_path *path = data;
-	struct pgpath *pgpath = path_to_pgpath(path);
+	struct pgpath *pgpath = data;
 	struct priority_group *pg = pgpath->pg;
 	struct multipath *m = pg->m;
 	unsigned long flags;
@@ -1143,8 +1177,8 @@ static void pg_init_done(void *data, int errors)
 			errors = 0;
 			break;
 		}
-		DMERR("Cannot failover device because scsi_dh_%s was not "
-		      "loaded.", m->hw_handler_name);
+		DMERR("Could not failover the device: Handler scsi_dh_%s "
+		      "Error %d.", m->hw_handler_name, errors);
 		/*
 		 * Fail path for now, so we do not ping pong
 		 */
@@ -1181,14 +1215,24 @@ static void pg_init_done(void *data, int errors)
 			m->current_pgpath = NULL;
 			m->current_pg = NULL;
 		}
-	} else if (!m->pg_init_required) {
-		m->queue_io = 0;
+	} else if (!m->pg_init_required)
 		pg->bypassed = 0;
-	}
 
-	m->pg_init_in_progress--;
-	if (!m->pg_init_in_progress)
-		queue_work(kmultipathd, &m->process_queued_ios);
+	if (--m->pg_init_in_progress)
+		/* Activations of other paths are still on going */
+		goto out;
+
+	if (!m->pg_init_required)
+		m->queue_io = 0;
+
+	queue_work(kmultipathd, &m->process_queued_ios);
+
+	/*
+	 * Wake up any thread waiting to suspend.
+	 */
+	wake_up(&m->pg_init_wait);
+
+out:
 	spin_unlock_irqrestore(&m->lock, flags);
 }
 
@@ -1198,7 +1242,7 @@ static void activate_path(struct work_struct *work)
 		container_of(work, struct pgpath, activate_path);
 
 	scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
-				pg_init_done, &pgpath->path);
+				pg_init_done, pgpath);
 }
 
 /*
@@ -1276,8 +1320,7 @@ static void multipath_postsuspend(struct dm_target *ti)
 	struct multipath *m = ti->private;
 
 	mutex_lock(&m->work_mutex);
-	m->suspended = 1;
-	flush_multipath_work();
+	flush_multipath_work(m);
 	mutex_unlock(&m->work_mutex);
 }
 
@@ -1289,10 +1332,6 @@ static void multipath_resume(struct dm_target *ti)
 	struct multipath *m = (struct multipath *) ti->private;
 	unsigned long flags;
 
-	mutex_lock(&m->work_mutex);
-	m->suspended = 0;
-	mutex_unlock(&m->work_mutex);
-
 	spin_lock_irqsave(&m->lock, flags);
 	m->queue_if_no_path = m->saved_queue_if_no_path;
 	spin_unlock_irqrestore(&m->lock, flags);
@@ -1428,11 +1467,6 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
 
 	mutex_lock(&m->work_mutex);
 
-	if (m->suspended) {
-		r = -EBUSY;
-		goto out;
-	}
-
 	if (dm_suspended(ti)) {
 		r = -EBUSY;
 		goto out;
@@ -1471,8 +1505,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
 		goto out;
 	}
 
-	r = dm_get_device(ti, argv[1], ti->begin, ti->len,
-			  dm_table_get_mode(ti->table), &dev);
+	r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
 	if (r) {
 		DMWARN("message: error getting device %s",
 		       argv[1]);
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 6c1046df81f..ddda531723d 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -465,9 +465,17 @@ static void map_region(struct dm_io_region *io, struct mirror *m,
 static void hold_bio(struct mirror_set *ms, struct bio *bio)
 {
 	/*
-	 * If device is suspended, complete the bio.
+	 * Lock is required to avoid race condition during suspend
+	 * process.
 	 */
+	spin_lock_irq(&ms->lock);
+
 	if (atomic_read(&ms->suspend)) {
+		spin_unlock_irq(&ms->lock);
+
+		/*
+		 * If device is suspended, complete the bio.
+		 */
 		if (dm_noflush_suspending(ms->ti))
 			bio_endio(bio, DM_ENDIO_REQUEUE);
 		else
@@ -478,7 +486,6 @@ static void hold_bio(struct mirror_set *ms, struct bio *bio)
 	/*
 	 * Hold bio until the suspend is complete.
 	 */
-	spin_lock_irq(&ms->lock);
 	bio_list_add(&ms->holds, bio);
 	spin_unlock_irq(&ms->lock);
 }
@@ -737,9 +744,12 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
 		dm_rh_delay(ms->rh, bio);
 
 	while ((bio = bio_list_pop(&nosync))) {
-		if (unlikely(ms->leg_failure) && errors_handled(ms))
-			hold_bio(ms, bio);
-		else {
+		if (unlikely(ms->leg_failure) && errors_handled(ms)) {
+			spin_lock_irq(&ms->lock);
+			bio_list_add(&ms->failures, bio);
+			spin_unlock_irq(&ms->lock);
+			wakeup_mirrord(ms);
+		} else {
 			map_bio(get_default_mirror(ms), bio);
 			generic_make_request(bio);
 		}
@@ -917,8 +927,7 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
 		return -EINVAL;
 	}
 
-	if (dm_get_device(ti, argv[0], offset, ti->len,
-			  dm_table_get_mode(ti->table),
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
 			  &ms->mirror[mirror].dev)) {
 		ti->error = "Device lookup failure";
 		return -ENXIO;
@@ -1259,6 +1268,20 @@ static void mirror_presuspend(struct dm_target *ti)
 	atomic_set(&ms->suspend, 1);
 
 	/*
+	 * Process bios in the hold list to start recovery waiting
+	 * for bios in the hold list. After the process, no bio has
+	 * a chance to be added in the hold list because ms->suspend
+	 * is set.
+	 */
+	spin_lock_irq(&ms->lock);
+	holds = ms->holds;
+	bio_list_init(&ms->holds);
+	spin_unlock_irq(&ms->lock);
+
+	while ((bio = bio_list_pop(&holds)))
+		hold_bio(ms, bio);
+
+	/*
 	 * We must finish up all the work that we've
 	 * generated (i.e. recovery work).
 	 */
@@ -1278,22 +1301,6 @@ static void mirror_presuspend(struct dm_target *ti)
 	 * we know that all of our I/O has been pushed.
 	 */
 	flush_workqueue(ms->kmirrord_wq);
-
-	/*
-	 * Now set ms->suspend is set and the workqueue flushed, no more
-	 * entries can be added to ms->hold list, so process it.
-	 *
-	 * Bios can still arrive concurrently with or after this
-	 * presuspend function, but they cannot join the hold list
-	 * because ms->suspend is set.
-	 */
-	spin_lock_irq(&ms->lock);
-	holds = ms->holds;
-	bio_list_init(&ms->holds);
-	spin_unlock_irq(&ms->lock);
-
-	while ((bio = bio_list_pop(&holds)))
-		hold_bio(ms, bio);
 }
 
 static void mirror_postsuspend(struct dm_target *ti)
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index ee8eb283650..54853773510 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -83,10 +83,10 @@ struct dm_snapshot {
 	/* Whether or not owning mapped_device is suspended */
 	int suspended;
 
-	mempool_t *pending_pool;
-
 	atomic_t pending_exceptions_count;
 
+	mempool_t *pending_pool;
+
 	struct dm_exception_table pending;
 	struct dm_exception_table complete;
 
@@ -96,6 +96,11 @@ struct dm_snapshot {
 	 */
 	spinlock_t pe_lock;
 
+	/* 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 */
 	struct dm_exception_store *store;
 
@@ -105,10 +110,12 @@ struct dm_snapshot {
 	struct bio_list queued_bios;
 	struct work_struct queued_bios_work;
 
-	/* Chunks with outstanding reads */
-	mempool_t *tracked_chunk_pool;
-	spinlock_t tracked_chunk_lock;
-	struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+	/* Wait for events based on state_bits */
+	unsigned long state_bits;
+
+	/* Range of chunks currently being merged. */
+	chunk_t first_merging_chunk;
+	int num_merging_chunks;
 
 	/*
 	 * The merge operation failed if this flag is set.
@@ -125,13 +132,6 @@ struct dm_snapshot {
 	 */
 	int merge_failed;
 
-	/* Wait for events based on state_bits */
-	unsigned long state_bits;
-
-	/* Range of chunks currently being merged. */
-	chunk_t first_merging_chunk;
-	int num_merging_chunks;
-
 	/*
 	 * Incoming bios that overlap with chunks being merged must wait
 	 * for them to be committed.
@@ -1081,8 +1081,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	argv++;
 	argc--;
 
-	r = dm_get_device(ti, cow_path, 0, 0,
-			  FMODE_READ | FMODE_WRITE, &s->cow);
+	r = dm_get_device(ti, cow_path, FMODE_READ | FMODE_WRITE, &s->cow);
 	if (r) {
 		ti->error = "Cannot get COW device";
 		goto bad_cow;
@@ -1098,7 +1097,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	argv += args_used;
 	argc -= args_used;
 
-	r = dm_get_device(ti, origin_path, 0, ti->len, origin_mode, &s->origin);
+	r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
 	if (r) {
 		ti->error = "Cannot get origin device";
 		goto bad_origin;
@@ -2100,8 +2099,7 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -EINVAL;
 	}
 
-	r = dm_get_device(ti, argv[0], 0, ti->len,
-			  dm_table_get_mode(ti->table), &dev);
+	r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
 	if (r) {
 		ti->error = "Cannot get target device";
 		return r;
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index bd58703ee8f..e610725db76 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -80,8 +80,7 @@ static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
 	if (sscanf(argv[1], "%llu", &start) != 1)
 		return -EINVAL;
 
-	if (dm_get_device(ti, argv[0], start, sc->stripe_width,
-			  dm_table_get_mode(ti->table),
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
 			  &sc->stripe[stripe].dev))
 		return -ENXIO;
 
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 4b22feb01a0..9924ea23032 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -429,8 +429,7 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
  * it's already present.
  */
 static int __table_get_device(struct dm_table *t, struct dm_target *ti,
-			      const char *path, sector_t start, sector_t len,
-			      fmode_t mode, struct dm_dev **result)
+		      const char *path, fmode_t mode, struct dm_dev **result)
 {
 	int r;
 	dev_t uninitialized_var(dev);
@@ -527,11 +526,10 @@ int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 }
 EXPORT_SYMBOL_GPL(dm_set_device_limits);
 
-int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
-		  sector_t len, fmode_t mode, struct dm_dev **result)
+int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
+		  struct dm_dev **result)
 {
-	return __table_get_device(ti->table, ti, path,
-				  start, len, mode, result);
+	return __table_get_device(ti->table, ti, path, mode, result);
 }
 
 
@@ -1231,8 +1229,6 @@ void dm_table_unplug_all(struct dm_table *t)
 
 struct mapped_device *dm_table_get_md(struct dm_table *t)
 {
-	dm_get(t->md);
-
 	return t->md;
 }
 
diff --git a/drivers/md/dm-uevent.c b/drivers/md/dm-uevent.c
index c7c555a8c7b..6b1e3b61b25 100644
--- a/drivers/md/dm-uevent.c
+++ b/drivers/md/dm-uevent.c
@@ -187,7 +187,7 @@ void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
 
 	if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
 		DMERR("%s: Invalid event_type %d", __func__, event_type);
-		goto out;
+		return;
 	}
 
 	event = dm_build_path_uevent(md, ti,
@@ -195,12 +195,9 @@ void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
 				     _dm_uevent_type_names[event_type].name,
 				     path, nr_valid_paths);
 	if (IS_ERR(event))
-		goto out;
+		return;
 
 	dm_uevent_add(md, &event->elist);
-
-out:
-	dm_put(md);
 }
 EXPORT_SYMBOL_GPL(dm_path_uevent);
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index aa4e2aa86d4..d21e1284604 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -635,8 +635,10 @@ static void dec_pending(struct dm_io *io, int error)
 			if (!md->barrier_error && io_error != -EOPNOTSUPP)
 				md->barrier_error = io_error;
 			end_io_acct(io);
+			free_io(md, io);
 		} else {
 			end_io_acct(io);
+			free_io(md, io);
 
 			if (io_error != DM_ENDIO_REQUEUE) {
 				trace_block_bio_complete(md->queue, bio);
@@ -644,8 +646,6 @@ static void dec_pending(struct dm_io *io, int error)
 				bio_endio(bio, io_error);
 			}
 		}
-
-		free_io(md, io);
 	}
 }
 
@@ -2618,18 +2618,19 @@ out:
 /*-----------------------------------------------------------------
  * Event notification.
  *---------------------------------------------------------------*/
-void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
+int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 		       unsigned cookie)
 {
 	char udev_cookie[DM_COOKIE_LENGTH];
 	char *envp[] = { udev_cookie, NULL };
 
 	if (!cookie)
-		kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
+		return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
 	else {
 		snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
 			 DM_COOKIE_ENV_VAR_NAME, cookie);
-		kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp);
+		return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
+					  action, envp);
 	}
 }
 
@@ -2699,23 +2700,13 @@ int dm_suspended_md(struct mapped_device *md)
 
 int dm_suspended(struct dm_target *ti)
 {
-	struct mapped_device *md = dm_table_get_md(ti->table);
-	int r = dm_suspended_md(md);
-
-	dm_put(md);
-
-	return r;
+	return dm_suspended_md(dm_table_get_md(ti->table));
 }
 EXPORT_SYMBOL_GPL(dm_suspended);
 
 int dm_noflush_suspending(struct dm_target *ti)
 {
-	struct mapped_device *md = dm_table_get_md(ti->table);
-	int r = __noflush_suspending(md);
-
-	dm_put(md);
-
-	return r;
+	return __noflush_suspending(dm_table_get_md(ti->table));
 }
 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
 
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 8dadaa5bc39..bad1724d486 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -125,8 +125,8 @@ void dm_stripe_exit(void);
 int dm_open_count(struct mapped_device *md);
 int dm_lock_for_deletion(struct mapped_device *md);
 
-void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
-		       unsigned cookie);
+int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
+		      unsigned cookie);
 
 int dm_io_init(void);
 void dm_io_exit(void);
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index d4c9c0b88ad..1381cd97b4e 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -118,10 +118,9 @@ struct dm_dev {
 /*
  * Constructors should call these functions to ensure destination devices
  * are opened/closed correctly.
- * FIXME: too many arguments.
  */
-int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
-		  sector_t len, fmode_t mode, struct dm_dev **result);
+int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
+						 struct dm_dev **result);
 void dm_put_device(struct dm_target *ti, struct dm_dev *d);
 
 /*
diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h
index b6bf17ee2f6..5c9186b93ff 100644
--- a/include/linux/dm-io.h
+++ b/include/linux/dm-io.h
@@ -37,14 +37,14 @@ enum dm_io_mem_type {
 struct dm_io_memory {
 	enum dm_io_mem_type type;
 
+	unsigned offset;
+
 	union {
 		struct page_list *pl;
 		struct bio_vec *bvec;
 		void *vma;
 		void *addr;
 	} ptr;
-
-	unsigned offset;
 };
 
 struct dm_io_notify {
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index aa95508d2f9..2c445e11379 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -266,9 +266,9 @@ enum {
 #define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR	4
-#define DM_VERSION_MINOR	16
+#define DM_VERSION_MINOR	17
 #define DM_VERSION_PATCHLEVEL	0
-#define DM_VERSION_EXTRA	"-ioctl (2009-11-05)"
+#define DM_VERSION_EXTRA	"-ioctl (2010-03-05)"
 
 /* Status bits */
 #define DM_READONLY_FLAG	(1 << 0) /* In/Out */
@@ -316,4 +316,9 @@ enum {
  */
 #define DM_QUERY_INACTIVE_TABLE_FLAG	(1 << 12) /* In */
 
+/*
+ * If set, a uevent was generated for which the caller may need to wait.
+ */
+#define DM_UEVENT_GENERATED_FLAG	(1 << 13) /* Out */
+
 #endif				/* _LINUX_DM_IOCTL_H */