From bd517df3bdad5f74fcd4f77e8c6eb5078d7ab1cd Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Wed, 17 Jan 2024 18:59:44 +0100 Subject: [PATCH] rbd: don't move requests to the running list on errors commit ded080c86b3f99683774af0441a58fc2e3d60cae upstream. The running list is supposed to contain requests that are pinning the exclusive lock, i.e. those that must be flushed before exclusive lock is released. When wake_lock_waiters() is called to handle an error, requests on the acquiring list are failed with that error and no flushing takes place. Briefly moving them to the running list is not only pointless but also harmful: if exclusive lock gets acquired before all of their state machines are scheduled and go through rbd_lock_del_request(), we trigger rbd_assert(list_empty(&rbd_dev->running_list)); in rbd_try_acquire_lock(). Cc: stable@vger.kernel.org Fixes: 637cd060537d ("rbd: new exclusive lock wait/wake code") Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang Signed-off-by: Greg Kroah-Hartman --- drivers/block/rbd.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 7117fa490243..fd0cdced8024 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3603,14 +3603,15 @@ static bool rbd_lock_add_request(struct rbd_img_request *img_req) static void rbd_lock_del_request(struct rbd_img_request *img_req) { struct rbd_device *rbd_dev = img_req->rbd_dev; - bool need_wakeup; + bool need_wakeup = false; lockdep_assert_held(&rbd_dev->lock_rwsem); spin_lock(&rbd_dev->lock_lists_lock); - rbd_assert(!list_empty(&img_req->lock_item)); - list_del_init(&img_req->lock_item); - need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING && - list_empty(&rbd_dev->running_list)); + if (!list_empty(&img_req->lock_item)) { + list_del_init(&img_req->lock_item); + need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING && + list_empty(&rbd_dev->running_list)); + } spin_unlock(&rbd_dev->lock_lists_lock); if (need_wakeup) complete(&rbd_dev->releasing_wait); @@ -3997,14 +3998,19 @@ static void wake_lock_waiters(struct rbd_device *rbd_dev, int result) return; } - list_for_each_entry(img_req, &rbd_dev->acquiring_list, lock_item) { + while (!list_empty(&rbd_dev->acquiring_list)) { + img_req = list_first_entry(&rbd_dev->acquiring_list, + struct rbd_img_request, lock_item); mutex_lock(&img_req->state_mutex); rbd_assert(img_req->state == RBD_IMG_EXCLUSIVE_LOCK); + if (!result) + list_move_tail(&img_req->lock_item, + &rbd_dev->running_list); + else + list_del_init(&img_req->lock_item); rbd_img_schedule(img_req, result); mutex_unlock(&img_req->state_mutex); } - - list_splice_tail_init(&rbd_dev->acquiring_list, &rbd_dev->running_list); } static int get_lock_owner_info(struct rbd_device *rbd_dev,