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Commit eaf9a736 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: set DMF_SUSPENDED* _before_ clearing DMF_NOFLUSH_SUSPENDING 



Otherwise, there is potential for both DMF_SUSPENDED* and
DMF_NOFLUSH_SUSPENDING to not be set during dm_suspend() -- which is
definitely _not_ a valid state.

This fix, in conjuction with "dm rq: fix the starting and stopping of
blk-mq queues", addresses the potential for request-based DM multipath's
__multipath_map() to see !dm_noflush_suspending() during suspend.

Reported-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
parent 7d9595d8

drivers/md/dm.c

+7 −7
Original line number Diff line number Diff line
@@ -2082,7 +2082,8 @@ static void unlock_fs(struct mapped_device *md) 
 * Caller must hold md->suspend_lock

 */

static int __dm_suspend(struct mapped_device *md, struct dm_table *map,

			unsigned suspend_flags, int interruptible)

			unsigned suspend_flags, int interruptible,

			int dmf_suspended_flag)

{

	bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;

	bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
@@ -2149,6 +2150,8 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map, 
	 * to finish.

	 */

	r = dm_wait_for_completion(md, interruptible);

	if (!r)

		set_bit(dmf_suspended_flag, &md->flags);



	if (noflush)

		clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
@@ -2210,12 +2213,10 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) 


	map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));



	r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE);

	r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);

	if (r)

		goto out_unlock;



	set_bit(DMF_SUSPENDED, &md->flags);



	dm_table_postsuspend_targets(map);



out_unlock:
@@ -2309,9 +2310,8 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla 
	 * would require changing .presuspend to return an error -- avoid this

	 * until there is a need for more elaborate variants of internal suspend.

	 */

	(void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE);



	set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);

	(void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,

			    DMF_SUSPENDED_INTERNALLY);



	dm_table_postsuspend_targets(map);

}