From: Md Haris Iqbal haris.iqbal@ionos.com
[ Upstream commit 4bc14f3101364877dd59085f39e068a2a7ec9f2d ]
After setting keep_id if the mutex trylock fails, the keep_id stays set for the rest of the sess_dev lifetime.
Therefore, set keep_id to true after mutex_trylock succeeds, so that a failure of trylock does'nt touch keep_id.
Fixes: b168e1d85cf3 ("block/rnbd-srv: Prevent a deadlock generated by accessing sysfs in parallel") Cc: gi-oh.kim@ionos.com Signed-off-by: Md Haris Iqbal haris.iqbal@ionos.com Signed-off-by: Jack Wang jinpu.wang@ionos.com Link: https://lore.kernel.org/r/20220707143122.460362-2-haris.iqbal@ionos.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/rnbd/rnbd-srv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c index beaef43a67b9..cf9e29a08db2 100644 --- a/drivers/block/rnbd/rnbd-srv.c +++ b/drivers/block/rnbd/rnbd-srv.c @@ -323,10 +323,11 @@ void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev, { struct rnbd_srv_session *sess = sess_dev->sess;
- sess_dev->keep_id = true; /* It is already started to close by client's close message. */ if (!mutex_trylock(&sess->lock)) return; + + sess_dev->keep_id = true; /* first remove sysfs itself to avoid deadlock */ sysfs_remove_file_self(&sess_dev->kobj, &attr->attr); rnbd_srv_destroy_dev_session_sysfs(sess_dev);