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| author |   Ilya Dryomov <idryomov@gmail.com> | 2021-07-03 11:56:55 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2021-07-20 17:57:33 +0200 |
| commit | 8798d070d416d18a75770fc19787e96705073f43 (patch) | |
| tree | 6dac63e7869b10fa1ec52870d007823ca660bfdf /drivers/block/rbd.c | |
| parent | Linux 5.14-rc2 (diff) | |
| download | linux-dev-8798d070d416d18a75770fc19787e96705073f43.tar.xz linux-dev-8798d070d416d18a75770fc19787e96705073f43.zip | |
rbd: always kick acquire on "acquired" and "released" notifications
Skipping the "lock has been released" notification if the lock owner
is not what we expect based on owner_cid can lead to I/O hangs.
One example is our own notifications: because owner_cid is cleared
in rbd_unlock(), when we get our own notification it is processed as
unexpected/duplicate and maybe_kick_acquire() isn't called. If a peer
that requested the lock then doesn't go through with acquiring it,
I/O requests that came in while the lock was being quiesced would
be stalled until another I/O request is submitted and kicks acquire
from rbd_img_exclusive_lock().
This makes the comment in rbd_release_lock() actually true: prior to
this change the canceled work was being requeued in response to the
"lock has been acquired" notification from rbd_handle_acquired_lock().
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Robin Geuze <robin.geuze@nl.team.blue>
Diffstat (limited to '')
| -rw-r--r-- | drivers/block/rbd.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 531d390902dd..e77cea6a6189 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4203,15 +4203,11 @@ static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v, if (!rbd_cid_equal(&cid, &rbd_empty_cid)) { down_write(&rbd_dev->lock_rwsem); if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) { - /* - * we already know that the remote client is - * the owner - */ - up_write(&rbd_dev->lock_rwsem); - return; + dout("%s rbd_dev %p cid %llu-%llu == owner_cid\n", + __func__, rbd_dev, cid.gid, cid.handle); + } else { + rbd_set_owner_cid(rbd_dev, &cid); } - - rbd_set_owner_cid(rbd_dev, &cid); downgrade_write(&rbd_dev->lock_rwsem); } else { down_read(&rbd_dev->lock_rwsem); @@ -4236,14 +4232,12 @@ static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v, if (!rbd_cid_equal(&cid, &rbd_empty_cid)) { down_write(&rbd_dev->lock_rwsem); if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) { - dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n", + dout("%s rbd_dev %p cid %llu-%llu != owner_cid %llu-%llu\n", __func__, rbd_dev, cid.gid, cid.handle, rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle); - up_write(&rbd_dev->lock_rwsem); - return; + } else { + rbd_set_owner_cid(rbd_dev, &rbd_empty_cid); } - - rbd_set_owner_cid(rbd_dev, &rbd_empty_cid); downgrade_write(&rbd_dev->lock_rwsem); } else { down_read(&rbd_dev->lock_rwsem); |