From 1af2048a3e87b4e982c53ad8cfb0c75d1a9c0a73 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Sat, 2 Dec 2017 01:03:48 +0100 Subject: [PATCH] dm raid: fix deadlock caused by premature md_stop_writes() md_stop_writes() is called in raid_presuspend() causing deadlocks on bios submitted afterwards -- which happens on loaded raid sets with conversion requests. Fix by moving md_stop_writes() to raid_postsuspend(). NOTE: when the recovery's frozen (MD_RECOVERY_FROZEN), writes haven't been started (or are already stopped) so don't stop them again. Also remove superfluous readonly setting. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- drivers/md/dm-raid.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 6319d846e0ad..398314b6c31a 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3613,24 +3613,19 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs)); } -static void raid_presuspend(struct dm_target *ti) -{ - struct raid_set *rs = ti->private; - - md_stop_writes(&rs->md); -} - static void raid_postsuspend(struct dm_target *ti) { struct raid_set *rs = ti->private; if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) { + /* Writes have to be stopped before suspending to avoid deadlocks. */ + if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery)) + md_stop_writes(&rs->md); + mddev_lock_nointr(&rs->md); mddev_suspend(&rs->md); mddev_unlock(&rs->md); } - - rs->md.ro = 1; } static void attempt_restore_of_faulty_devices(struct raid_set *rs) @@ -3903,7 +3898,6 @@ static struct target_type raid_target = { .message = raid_message, .iterate_devices = raid_iterate_devices, .io_hints = raid_io_hints, - .presuspend = raid_presuspend, .postsuspend = raid_postsuspend, .preresume = raid_preresume, .resume = raid_resume,