From f5c466a0fdb2d9f3650d2e3911b0735f17ba00cf Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 23 Jul 2024 17:54:39 +0200 Subject: rbd: rename RBD_LOCK_STATE_RELEASING and releasing_wait ... to RBD_LOCK_STATE_QUIESCING and quiescing_wait to recognize that this state and the associated completion are backing rbd_quiesce_lock(), which isn't specific to releasing the lock. While exclusive lock does get quiesced before it's released, it also gets quiesced before an attempt to update the cookie is made and there the lock is not released as long as ceph_cls_set_cookie() succeeds. Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang --- drivers/block/rbd.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'drivers') diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 26ff5cd2bf0a..c30d227753d7 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -362,7 +362,7 @@ enum rbd_watch_state { enum rbd_lock_state { RBD_LOCK_STATE_UNLOCKED, RBD_LOCK_STATE_LOCKED, - RBD_LOCK_STATE_RELEASING, + RBD_LOCK_STATE_QUIESCING, }; /* WatchNotify::ClientId */ @@ -422,7 +422,7 @@ struct rbd_device { struct list_head running_list; struct completion acquire_wait; int acquire_err; - struct completion releasing_wait; + struct completion quiescing_wait; spinlock_t object_map_lock; u8 *object_map; @@ -525,7 +525,7 @@ static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev) lockdep_assert_held(&rbd_dev->lock_rwsem); return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED || - rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING; + rbd_dev->lock_state == RBD_LOCK_STATE_QUIESCING; } static bool rbd_is_lock_owner(struct rbd_device *rbd_dev) @@ -3458,12 +3458,12 @@ static void rbd_lock_del_request(struct rbd_img_request *img_req) spin_lock(&rbd_dev->lock_lists_lock); if (!list_empty(&img_req->lock_item)) { list_del_init(&img_req->lock_item); - need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING && + need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_QUIESCING && list_empty(&rbd_dev->running_list)); } spin_unlock(&rbd_dev->lock_lists_lock); if (need_wakeup) - complete(&rbd_dev->releasing_wait); + complete(&rbd_dev->quiescing_wait); } static int rbd_img_exclusive_lock(struct rbd_img_request *img_req) @@ -4181,16 +4181,16 @@ static bool rbd_quiesce_lock(struct rbd_device *rbd_dev) /* * Ensure that all in-flight IO is flushed. */ - rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING; - rbd_assert(!completion_done(&rbd_dev->releasing_wait)); + rbd_dev->lock_state = RBD_LOCK_STATE_QUIESCING; + rbd_assert(!completion_done(&rbd_dev->quiescing_wait)); if (list_empty(&rbd_dev->running_list)) return true; up_write(&rbd_dev->lock_rwsem); - wait_for_completion(&rbd_dev->releasing_wait); + wait_for_completion(&rbd_dev->quiescing_wait); down_write(&rbd_dev->lock_rwsem); - if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING) + if (rbd_dev->lock_state != RBD_LOCK_STATE_QUIESCING) return false; rbd_assert(list_empty(&rbd_dev->running_list)); @@ -5383,7 +5383,7 @@ static struct rbd_device *__rbd_dev_create(struct rbd_spec *spec) INIT_LIST_HEAD(&rbd_dev->acquiring_list); INIT_LIST_HEAD(&rbd_dev->running_list); init_completion(&rbd_dev->acquire_wait); - init_completion(&rbd_dev->releasing_wait); + init_completion(&rbd_dev->quiescing_wait); spin_lock_init(&rbd_dev->object_map_lock); -- cgit From 2237ceb71f89837ac47c5dce2aaa2c2b3a337a3c Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 23 Jul 2024 18:07:59 +0200 Subject: rbd: don't assume RBD_LOCK_STATE_LOCKED for exclusive mappings Every time a watch is reestablished after getting lost, we need to update the cookie which involves quiescing exclusive lock. For this, we transition from RBD_LOCK_STATE_LOCKED to RBD_LOCK_STATE_QUIESCING roughly for the duration of rbd_reacquire_lock() call. If the mapping is exclusive and I/O happens to arrive in this time window, it's failed with EROFS (later translated to EIO) based on the wrong assumption in rbd_img_exclusive_lock() -- "lock got released?" check there stopped making sense with commit a2b1da09793d ("rbd: lock should be quiesced on reacquire"). To make it worse, any such I/O is added to the acquiring list before EROFS is returned and this sets up for violating rbd_lock_del_request() precondition that the request is either on the running list or not on any list at all -- see commit ded080c86b3f ("rbd: don't move requests to the running list on errors"). rbd_lock_del_request() ends up processing these requests as if they were on the running list which screws up quiescing_wait completion counter and ultimately leads to rbd_assert(!completion_done(&rbd_dev->quiescing_wait)); being triggered on the next watch error. Cc: stable@vger.kernel.org # 06ef84c4e9c4: rbd: rename RBD_LOCK_STATE_RELEASING and releasing_wait Cc: stable@vger.kernel.org Fixes: 637cd060537d ("rbd: new exclusive lock wait/wake code") Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang --- drivers/block/rbd.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index c30d227753d7..ea6c592e015c 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3457,6 +3457,7 @@ static void rbd_lock_del_request(struct rbd_img_request *img_req) lockdep_assert_held(&rbd_dev->lock_rwsem); spin_lock(&rbd_dev->lock_lists_lock); if (!list_empty(&img_req->lock_item)) { + rbd_assert(!list_empty(&rbd_dev->running_list)); list_del_init(&img_req->lock_item); need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_QUIESCING && list_empty(&rbd_dev->running_list)); @@ -3476,11 +3477,6 @@ static int rbd_img_exclusive_lock(struct rbd_img_request *img_req) if (rbd_lock_add_request(img_req)) return 1; - if (rbd_dev->opts->exclusive) { - WARN_ON(1); /* lock got released? */ - return -EROFS; - } - /* * Note the use of mod_delayed_work() in rbd_acquire_lock() * and cancel_delayed_work() in wake_lock_waiters(). @@ -4601,6 +4597,10 @@ static void rbd_reacquire_lock(struct rbd_device *rbd_dev) rbd_warn(rbd_dev, "failed to update lock cookie: %d", ret); + if (rbd_dev->opts->exclusive) + rbd_warn(rbd_dev, + "temporarily releasing lock on exclusive mapping"); + /* * Lock cookie cannot be updated on older OSDs, so do * a manual release and queue an acquire. -- cgit From 3ceccb14f5576e02b81cc8b105ab81f224bd87f6 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 23 Jul 2024 18:08:08 +0200 Subject: rbd: don't assume rbd_is_lock_owner() for exclusive mappings Expanding on the previous commit, assuming that rbd_is_lock_owner() always returns true (i.e. that we are either in RBD_LOCK_STATE_LOCKED or RBD_LOCK_STATE_QUIESCING) if the mapping is exclusive is wrong too. In case ceph_cls_set_cookie() fails, the lock would be temporarily released even if the mapping is exclusive, meaning that we can end up even in RBD_LOCK_STATE_UNLOCKED. IOW, exclusive mappings are really "just" about disabling automatic lock transitions (as documented in the man page), not about grabbing the lock and holding on to it whatever it takes. Cc: stable@vger.kernel.org Fixes: 637cd060537d ("rbd: new exclusive lock wait/wake code") Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang --- drivers/block/rbd.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers') diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index ea6c592e015c..da22ce38c039 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -6589,11 +6589,6 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) if (ret) return ret; - /* - * The lock may have been released by now, unless automatic lock - * transitions are disabled. - */ - rbd_assert(!rbd_dev->opts->exclusive || rbd_is_lock_owner(rbd_dev)); return 0; } -- cgit