Patch "dm: set DMF_SUSPENDED* _before_ clearing DMF_NOFLUSH_SUSPENDING" has been added to the 4.4-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2016-08-18 09:10:48
This is a note to let you know that I've just added the patch titled
dm: set DMF_SUSPENDED* _before_ clearing DMF_NOFLUSH_SUSPENDING
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-set-dmf_suspended-_before_-clearing-dmf_noflush_suspending.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From eaf9a7361f47727b166688a9f2096854eef60fbe Mon Sep 17 00:00:00 2001
From: Mike Snitzer <redacted> Date: Tue, 2 Aug 2016 13:07:20 -0400 Subject: dm: set DMF_SUSPENDED* _before_ clearing DMF_NOFLUSH_SUSPENDING From: Mike Snitzer <redacted> commit eaf9a7361f47727b166688a9f2096854eef60fbe upstream. 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 <redacted> Signed-off-by: Mike Snitzer <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/md/dm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c@@ -3078,7 +3078,8 @@ static void unlock_fs(struct mapped_devi * 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;
@@ -3145,6 +3146,8 @@ static int __dm_suspend(struct mapped_de * 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);
@@ -3206,12 +3209,10 @@ 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:
@@ -3305,9 +3306,8 @@ static void __dm_internal_suspend(struct * 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); }
Patches currently in stable-queue which might be from snitzer@redhat.com are queue-4.4/dm-set-dmf_suspended-_before_-clearing-dmf_noflush_suspending.patch