struct rw_semaphore snap_rwsem;
struct rb_root snap_realms;
struct list_head snap_empty;
spinlock_t snap_empty_lock; /* protect snap_empty */
u64 last_tid; /* most recent mds request */
struct rw_semaphore snap_rwsem;
struct rb_root snap_realms;
struct list_head snap_empty;
spinlock_t snap_empty_lock; /* protect snap_empty */
u64 last_tid; /* most recent mds request */