kernel/linux.git/drivers/block/rbd.c, branch v6.6.132

rbd: check for EOD after exclusive lock is ensured to be held

2026-02-11T12:39:08+00:00

commit bd3884a204c3b507e6baa9a4091aa927f9af5404 upstream. Similar to commit 870611e4877e ("rbd: get snapshot context after exclusive lock is ensured to be held"), move the "beyond EOD" check into the image request state machine so that it's performed after exclusive lock is ensured to be held. This avoids various race conditions which can arise when the image is shrunk under I/O (in practice, mostly readahead). In one such scenario rbd_assert(objno < rbd_dev->object_map_size); can be triggered if a close-to-EOD read gets queued right before the shrink is initiated and the EOD check is performed against an outdated mapping_size. After the resize is done on the server side and exclusive lock is (re)acquired bringing along the new (now shrunk) object map, the read starts going through the state machine and rbd_obj_may_exist() gets invoked on an object that is out of bounds of rbd_dev->object_map array. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang Signed-off-by: Greg Kroah-Hartman

rbd: don't assume RBD_LOCK_STATE_LOCKED for exclusive mappings

2024-08-03T06:54:32+00:00

commit 2237ceb71f89837ac47c5dce2aaa2c2b3a337a3c upstream. 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 Signed-off-by: Greg Kroah-Hartman

rbd: rename RBD_LOCK_STATE_RELEASING and releasing_wait

2024-08-03T06:54:32+00:00

commit f5c466a0fdb2d9f3650d2e3911b0735f17ba00cf upstream. ... 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 Signed-off-by: Greg Kroah-Hartman

rbd: don't assume rbd_is_lock_owner() for exclusive mappings

2024-08-03T06:54:30+00:00

commit 3ceccb14f5576e02b81cc8b105ab81f224bd87f6 upstream. 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 Signed-off-by: Greg Kroah-Hartman

rbd: don't move requests to the running list on errors

2024-02-01T00:19:06+00:00

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

rbd: take header_rwsem in rbd_dev_refresh() only when updating

2023-09-26T08:33:19+00:00

rbd_dev_refresh() has been holding header_rwsem across header and parent info read-in unnecessarily for ages. With commit 870611e4877e ("rbd: get snapshot context after exclusive lock is ensured to be held"), the potential for deadlocks became much more real owning to a) header_rwsem now nesting inside lock_rwsem and b) rw_semaphores not allowing new readers after a writer is registered. For example, assuming that I/O request 1, I/O request 2 and header read-in request all target the same OSD: 1. I/O request 1 comes in and gets submitted 2. watch error occurs 3. rbd_watch_errcb() takes lock_rwsem for write, clears owner_cid and releases lock_rwsem 4. after reestablishing the watch, rbd_reregister_watch() calls rbd_dev_refresh() which takes header_rwsem for write and submits a header read-in request 5. I/O request 2 comes in: after taking lock_rwsem for read in __rbd_img_handle_request(), it blocks trying to take header_rwsem for read in rbd_img_object_requests() 6. another watch error occurs 7. rbd_watch_errcb() blocks trying to take lock_rwsem for write 8. I/O request 1 completion is received by the messenger but can't be processed because lock_rwsem won't be granted anymore 9. header read-in request completion can't be received, let alone processed, because the messenger is stranded Change rbd_dev_refresh() to take header_rwsem only for actually updating rbd_dev->header. Header and parent info read-in don't need any locking. Cc: stable@vger.kernel.org # 0b035401c570: rbd: move rbd_dev_refresh() definition Cc: stable@vger.kernel.org # 510a7330c82a: rbd: decouple header read-in from updating rbd_dev->header Cc: stable@vger.kernel.org # c10311776f0a: rbd: decouple parent info read-in from updating rbd_dev Cc: stable@vger.kernel.org Fixes: 870611e4877e ("rbd: get snapshot context after exclusive lock is ensured to be held") Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang

rbd: decouple parent info read-in from updating rbd_dev

2023-09-26T08:31:33+00:00

Unlike header read-in, parent info read-in is already decoupled in get_parent_info(), but it's buried in rbd_dev_v2_parent_info() along with the processing logic. Separate the initial read-in and update read-in logic into rbd_dev_setup_parent() and rbd_dev_update_parent() respectively and have rbd_dev_v2_parent_info() just populate struct parent_image_info (i.e. what get_parent_info() did). Some existing QoI issues, like flatten of a standalone clone being disregarded on refresh, remain. Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang

rbd: decouple header read-in from updating rbd_dev->header

2023-09-26T08:31:31+00:00

Make rbd_dev_header_info() populate a passed struct rbd_image_header instead of rbd_dev->header and introduce rbd_dev_update_header() for updating mutable fields in rbd_dev->header upon refresh. The initial read-in of both mutable and immutable fields in rbd_dev_image_probe() passes in rbd_dev->header so no update step is required there. rbd_init_layout() is now called directly from rbd_dev_image_probe() instead of individually in format 1 and format 2 implementations. Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang

rbd: move rbd_dev_refresh() definition

2023-09-26T08:31:15+00:00

Move rbd_dev_refresh() definition further down to avoid having to move struct parent_image_info definition in the next commit. This spares some forward declarations too. Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang

rbd: use list_for_each_entry() helper

2023-08-30T09:51:55+00:00

Convert list_for_each() to list_for_each_entry() so that the tmp list_head pointer and list_entry() call are no longer needed, which can reduce a few lines of code. No functional changed. Signed-off-by: Jinjie Ruan Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov