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 <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
