From eaf9a7361f47727b166688a9f2096854eef60fbe Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 2 Aug 2016 13:07:20 -0400 Subject: [PATCH] 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: Bart Van Assche Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org --- drivers/md/dm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 25d1d97154a8..dfa09e14e847 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -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 @@ retry: 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); } -- 2.20.1