From 874807a83139abc094f939e93623c5623573d543 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 27 Nov 2012 12:14:40 +1100 Subject: md/raid1{,0}: fix deadlock in bitmap_unplug. If the raid1 or raid10 unplug function gets called from a make_request function (which is very possible) when there are bios on the current->bio_list list, then it will not be able to successfully call bitmap_unplug() and it could need to submit more bios and wait for them to complete. But they won't complete while current->bio_list is non-empty. So detect that case and handle the unplugging off to another thread just like we already do when called from within the scheduler. RAID1 version of bug was introduced in 3.6, so that part of fix is suitable for 3.6.y. RAID10 part won't apply. Cc: stable@vger.kernel.org Reported-by: Torsten Kaiser Reported-by: Peter Maloney Signed-off-by: NeilBrown --- drivers/md/raid1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/raid1.c') diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 636bae0..a0f7309 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -963,7 +963,7 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule) struct r1conf *conf = mddev->private; struct bio *bio; - if (from_schedule) { + if (from_schedule || current->bio_list) { spin_lock_irq(&conf->device_lock); bio_list_merge(&conf->pending_bio_list, &plug->pending); conf->pending_count += plug->pending_cnt; -- cgit v1.1