On Mon, Jul 27, 2020 at 10:56:35PM +0200, Pavel Machek wrote:
Hi!
From: Mikulas Patocka mpatocka@redhat.com
commit 5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 upstream.
Commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 ("dm: report suspended device during destroy") broke integrity recalculation.
The problem is dm_suspended() returns true not only during suspend, but also during resume. So this race condition could occur:
- dm_integrity_resume calls queue_work(ic->recalc_wq, &ic->recalc_work)
- integrity_recalc (&ic->recalc_work) preempts the current thread
- integrity_recalc calls if (unlikely(dm_suspended(ic->ti))) goto unlock_ret;
- integrity_recalc exits and no recalculating is done.
To fix this race condition, add a function dm_post_suspending that is only true during the postsuspend phase and use it instead of dm_suspended().
Signed-off-by: Mikulas Patocka <mpatocka redhat com>
Something is wrong with signoff here...
Heh, and the same thing happened with the stable tag:
Cc: stable vger kernel org # v4.18+
But given that this is the way the upstream commit looks like we can't do much here.