rbd: always kick acquire on "acquired" and "released" notifications
authorIlya Dryomov <idryomov@gmail.com>
Sat, 3 Jul 2021 09:56:55 +0000 (11:56 +0200)
committerIlya Dryomov <idryomov@gmail.com>
Tue, 20 Jul 2021 15:57:33 +0000 (17:57 +0200)
commit8798d070d416d18a75770fc19787e96705073f43
tree6dac63e7869b10fa1ec52870d007823ca660bfdf
parent2734d6c1b1a089fb593ef6a23d4b70903526fe0c
rbd: always kick acquire on "acquired" and "released" notifications

Skipping the "lock has been released" notification if the lock owner
is not what we expect based on owner_cid can lead to I/O hangs.
One example is our own notifications: because owner_cid is cleared
in rbd_unlock(), when we get our own notification it is processed as
unexpected/duplicate and maybe_kick_acquire() isn't called.  If a peer
that requested the lock then doesn't go through with acquiring it,
I/O requests that came in while the lock was being quiesced would
be stalled until another I/O request is submitted and kicks acquire
from rbd_img_exclusive_lock().

This makes the comment in rbd_release_lock() actually true: prior to
this change the canceled work was being requeued in response to the
"lock has been acquired" notification from rbd_handle_acquired_lock().

Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Robin Geuze <robin.geuze@nl.team.blue>
drivers/block/rbd.c