+ /* reserve quota for delayed block allocation */
+ int (*reserve_space) (struct inode *, qsize_t, int);
+ /* claim reserved quota for delayed alloc */
+ int (*claim_space) (struct inode *, qsize_t);
+ /* release rsved quota for delayed alloc */
+ void (*release_rsv) (struct inode *, qsize_t);
+ /* get reserved quota for delayed alloc */
+ qsize_t (*get_reserved_space) (struct inode *);