md: using GFP_NOIO to allocate bio for flush request

commit b5e1b8cee7 upstream.

A flush request is usually issued in transaction commit code path, so
using GFP_KERNEL to allocate memory for flush request bio falls into
the classic deadlock issue.

This is suitable for any -stable kernel to which it applies as it
avoids a possible deadlock.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Shaohua Li 2012-05-21 09:26:59 +10:00 committed by Greg Kroah-Hartman
parent beb9576530
commit 85968a996b

View File

@ -409,7 +409,7 @@ static void submit_flushes(struct work_struct *ws)
atomic_inc(&rdev->nr_pending);
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
bi->bi_bdev = rdev->bdev;