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authorIlya Dryomov <idryomov@gmail.com>2019-05-30 12:15:23 +0300
committerIlya Dryomov <idryomov@gmail.com>2019-07-08 15:01:45 +0300
commita2b1da09793d003410b57f96eaf7e83e43b7a50a (patch)
tree9f9c5a9723b3bebb43b7c6460327b00f99675e9c /drivers/block/rbd.c
parent793333a303c90174c317e3fa12e898bbc02daee4 (diff)
downloadlinux-a2b1da09793d003410b57f96eaf7e83e43b7a50a.tar.xz
rbd: lock should be quiesced on reacquire
Quiesce exclusive lock at the top of rbd_reacquire_lock() instead of only when ceph_cls_set_cookie() fails. This avoids a deadlock on rbd_dev->lock_rwsem. If rbd_dev->lock_rwsem is needed for I/O completion, set_cookie can hang ceph-msgr worker thread if set_cookie reply ends up behind an I/O reply, because, like lock and unlock requests, set_cookie is sent and waited upon with rbd_dev->lock_rwsem held for write. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Diffstat (limited to 'drivers/block/rbd.c')
-rw-r--r--drivers/block/rbd.c35
1 files changed, 21 insertions, 14 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 99a0ebbf379c..4ae1cdf40b27 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3004,6 +3004,7 @@ static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
{
struct rbd_client_id cid = rbd_get_cid(rbd_dev);
+ rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
strcpy(rbd_dev->lock_cookie, cookie);
rbd_set_owner_cid(rbd_dev, &cid);
queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
@@ -3028,7 +3029,6 @@ static int rbd_lock(struct rbd_device *rbd_dev)
if (ret)
return ret;
- rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
__rbd_lock(rbd_dev, cookie);
return 0;
}
@@ -3411,13 +3411,11 @@ again:
}
}
-/*
- * lock_rwsem must be held for write
- */
-static bool rbd_release_lock(struct rbd_device *rbd_dev)
+static bool rbd_quiesce_lock(struct rbd_device *rbd_dev)
{
- dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
- rbd_dev->lock_state);
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+ lockdep_assert_held_exclusive(&rbd_dev->lock_rwsem);
+
if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
return false;
@@ -3433,12 +3431,22 @@ static bool rbd_release_lock(struct rbd_device *rbd_dev)
up_read(&rbd_dev->lock_rwsem);
down_write(&rbd_dev->lock_rwsem);
- dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
- rbd_dev->lock_state);
if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
return false;
+ return true;
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static void rbd_release_lock(struct rbd_device *rbd_dev)
+{
+ if (!rbd_quiesce_lock(rbd_dev))
+ return;
+
rbd_unlock(rbd_dev);
+
/*
* Give others a chance to grab the lock - we would re-acquire
* almost immediately if we got new IO during ceph_osdc_sync()
@@ -3447,7 +3455,6 @@ static bool rbd_release_lock(struct rbd_device *rbd_dev)
* after wake_requests() in rbd_handle_released_lock().
*/
cancel_delayed_work(&rbd_dev->lock_dwork);
- return true;
}
static void rbd_release_lock_work(struct work_struct *work)
@@ -3795,7 +3802,8 @@ static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
char cookie[32];
int ret;
- WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
+ if (!rbd_quiesce_lock(rbd_dev))
+ return;
format_lock_cookie(rbd_dev, cookie);
ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
@@ -3811,9 +3819,8 @@ static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
* Lock cookie cannot be updated on older OSDs, so do
* a manual release and queue an acquire.
*/
- if (rbd_release_lock(rbd_dev))
- queue_delayed_work(rbd_dev->task_wq,
- &rbd_dev->lock_dwork, 0);
+ rbd_unlock(rbd_dev);
+ queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
} else {
__rbd_lock(rbd_dev, cookie);
}