rbd: store lock cookie

In preparation for supporting set_cookie method (or rather set_cookie
fallback for older OSDs), store the lock cookie on lock and use it on
unlock instead of recalculating from rbd_dev->watch_cookie.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 423de775aabb..5f563db59820 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -387,6 +387,7 @@ struct rbd_device {
 
         struct rw_semaphore     lock_rwsem;
         enum rbd_lock_state     lock_state;
+        char                    lock_cookie[32];
         struct rbd_client_id    owner_cid;
         struct work_struct      acquired_lock_work;
         struct work_struct      released_lock_work;
@@ -3079,7 +3080,8 @@ static int rbd_lock(struct rbd_device *rbd_dev)
         char cookie[32];
         int ret;
 
-        WARN_ON(__rbd_is_lock_owner(rbd_dev));
+        WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
+                rbd_dev->lock_cookie[0] != '\0');
 
         format_lock_cookie(rbd_dev, cookie);
         ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
@@ -3089,6 +3091,7 @@ static int rbd_lock(struct rbd_device *rbd_dev)
                 return ret;
 
         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);
         return 0;
@@ -3100,19 +3103,19 @@ static int rbd_lock(struct rbd_device *rbd_dev)
 static void rbd_unlock(struct rbd_device *rbd_dev)
 {
         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
-        char cookie[32];
         int ret;
 
-        WARN_ON(!__rbd_is_lock_owner(rbd_dev));
+        WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
+                rbd_dev->lock_cookie[0] == '\0');
 
-        format_lock_cookie(rbd_dev, cookie);
         ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
-                              RBD_LOCK_NAME, cookie);
+                              RBD_LOCK_NAME, rbd_dev->lock_cookie);
         if (ret && ret != -ENOENT)
                 rbd_warn(rbd_dev, "failed to unlock: %d", ret);
 
         /* treat errors as the image is unlocked */
         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
+        rbd_dev->lock_cookie[0] = '\0';
         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
         queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
 }