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>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 423de775aabb6670958436411667396ad60525cc..5f563db598202f9d02a0ef639fc6d99840c31ae1 100644 (file)
--- 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);
 }