md/raid1: intialise start_next_window for READ case to avoid hang
r1_bio->start_next_window is not initialised in the READ
case, so allow_barrier may incorrectly decrement
conf->current_window_requests
which can cause raise_barrier() to block forever.
Fixes: 79ef3a8aa1cb1523cc231c9a90a278333c21f761
cc: stable@vger.kernel.org (v3.13+)
Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d7690f8..9ebccf62 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1186,6 +1186,7 @@
atomic_read(&bitmap->behind_writes) == 0);
}
r1_bio->read_disk = rdisk;
+ r1_bio->start_next_window = 0;
read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,