Merge tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "A dm-cache stable fix to split discards on cache block boundaries
  because dm-cache cannot yet handle discards that span cache blocks.

  Really fix a dm-mpath LOCKDEP warning that was introduced in -rc1.

  Add a 'no_space_timeout' control to dm-thinp to restore the ability to
  queue IO indefinitely when no data space is available.  This fixes a
  change in behavior that was introduced in -rc6 where the timeout
  couldn't be disabled"

* tag 'dm-3.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: really fix lockdep warning
  dm cache: always split discards on cache block boundaries
  dm thin: add 'no_space_timeout' dm-thin-pool module param

Documentation/device-mapper/thin-provisioning.txt

@@ -309,7 +309,10 @@ ii) Status
     error_if_no_space|queue_if_no_space
 	If the pool runs out of data or metadata space, the pool will
 	either queue or error the IO destined to the data device.  The
-	default is to queue the IO until more space is added.
+	default is to queue the IO until more space is added or the
+	'no_space_timeout' expires.  The 'no_space_timeout' dm-thin-pool
+	module parameter can be used to change this timeout -- it
+	defaults to 60 seconds but may be disabled using a value of 0.
 
 iii) Messages
 

drivers/md/dm-cache-target.c

@@ -2178,6 +2178,8 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 	ti->num_discard_bios = 1;
 	ti->discards_supported = true;
 	ti->discard_zeroes_data_unsupported = true;
+	/* Discard bios must be split on a block boundary */
+	ti->split_discard_bios = true;
 
 	cache->features = ca->features;
 	ti->per_bio_data_size = get_per_bio_data_size(cache);

drivers/md/dm-mpath.c

@@ -445,11 +445,11 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path,
 	else
 		m->saved_queue_if_no_path = queue_if_no_path;
 	m->queue_if_no_path = queue_if_no_path;
-	if (!m->queue_if_no_path)
-		dm_table_run_md_queue_async(m->ti->table);
-
 	spin_unlock_irqrestore(&m->lock, flags);
 
+	if (!queue_if_no_path)
+		dm_table_run_md_queue_async(m->ti->table);
+
 	return 0;
 }
 
@@ -954,7 +954,7 @@ static int fail_path(struct pgpath *pgpath)
  */
 static int reinstate_path(struct pgpath *pgpath)
 {
-	int r = 0;
+	int r = 0, run_queue = 0;
 	unsigned long flags;
 	struct multipath *m = pgpath->pg->m;
 
@@ -978,7 +978,7 @@ static int reinstate_path(struct pgpath *pgpath)
 
 	if (!m->nr_valid_paths++) {
 		m->current_pgpath = NULL;
-		dm_table_run_md_queue_async(m->ti->table);
+		run_queue = 1;
 	} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
 		if (queue_work(kmpath_handlerd, &pgpath->activate_path.work))
 			m->pg_init_in_progress++;
@@ -991,6 +991,8 @@ static int reinstate_path(struct pgpath *pgpath)
 
 out:
 	spin_unlock_irqrestore(&m->lock, flags);
+	if (run_queue)
+		dm_table_run_md_queue_async(m->ti->table);
 
 	return r;
 }
@@ -1566,8 +1568,8 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
 		}
 		if (m->pg_init_required)
 			__pg_init_all_paths(m);
-		dm_table_run_md_queue_async(m->ti->table);
 		spin_unlock_irqrestore(&m->lock, flags);
+		dm_table_run_md_queue_async(m->ti->table);
 	}
 
 	return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);

drivers/md/dm-thin.c

@@ -27,7 +27,9 @@
 #define MAPPING_POOL_SIZE 1024
 #define PRISON_CELLS 1024
 #define COMMIT_PERIOD HZ
-#define NO_SPACE_TIMEOUT (HZ * 60)
+#define NO_SPACE_TIMEOUT_SECS 60
+
+static unsigned no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS;
 
 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
 		"A percentage of time allocated for copy on write");
@@ -1670,6 +1672,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
 	struct pool_c *pt = pool->ti->private;
 	bool needs_check = dm_pool_metadata_needs_check(pool->pmd);
 	enum pool_mode old_mode = get_pool_mode(pool);
+	unsigned long no_space_timeout = ACCESS_ONCE(no_space_timeout_secs) * HZ;
 
 	/*
 	 * Never allow the pool to transition to PM_WRITE mode if user
@@ -1732,8 +1735,8 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
 		pool->process_prepared_mapping = process_prepared_mapping;
 		pool->process_prepared_discard = process_prepared_discard_passdown;
 
-		if (!pool->pf.error_if_no_space)
-			queue_delayed_work(pool->wq, &pool->no_space_timeout, NO_SPACE_TIMEOUT);
+		if (!pool->pf.error_if_no_space && no_space_timeout)
+			queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout);
 		break;
 
 	case PM_WRITE:
@@ -3508,6 +3511,9 @@ static void dm_thin_exit(void)
 module_init(dm_thin_init);
 module_exit(dm_thin_exit);
 
+module_param_named(no_space_timeout, no_space_timeout_secs, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");
+
 MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
 MODULE_LICENSE("GPL");