1 /* 2 * direct.h - NILFS direct block pointer. 3 * 4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Written by Koji Sato <koji@osrg.net>. 21 */ 22 23 #ifndef _NILFS_DIRECT_H 24 #define _NILFS_DIRECT_H 25 26 #include <linux/types.h> 27 #include <linux/buffer_head.h> 28 #include "bmap.h" 29 30 31 struct nilfs_direct; 32 33 /** 34 * struct nilfs_direct_operations - direct mapping operation table 35 */ 36 struct nilfs_direct_operations { 37 __u64 (*dop_find_target)(const struct nilfs_direct *, __u64); 38 void (*dop_set_target)(struct nilfs_direct *, __u64, __u64); 39 int (*dop_propagate)(struct nilfs_direct *, struct buffer_head *); 40 int (*dop_assign)(struct nilfs_direct *, __u64, __u64, 41 struct buffer_head **, sector_t, 42 union nilfs_binfo *); 43 }; 44 45 /** 46 * struct nilfs_direct_node - direct node 47 * @dn_flags: flags 48 * @dn_pad: padding 49 */ 50 struct nilfs_direct_node { 51 __u8 dn_flags; 52 __u8 pad[7]; 53 }; 54 55 /** 56 * struct nilfs_direct - direct mapping 57 * @d_bmap: bmap structure 58 * @d_ops: direct mapping operation table 59 */ 60 struct nilfs_direct { 61 struct nilfs_bmap d_bmap; 62 63 /* direct-mapping-specific members */ 64 const struct nilfs_direct_operations *d_ops; 65 }; 66 67 68 #define NILFS_DIRECT_NBLOCKS (NILFS_BMAP_SIZE / sizeof(__le64) - 1) 69 #define NILFS_DIRECT_KEY_MIN 0 70 #define NILFS_DIRECT_KEY_MAX (NILFS_DIRECT_NBLOCKS - 1) 71 72 73 int nilfs_direct_init(struct nilfs_bmap *, __u64, __u64); 74 int nilfs_direct_delete_and_convert(struct nilfs_bmap *, __u64, __u64 *, 75 __u64 *, int, __u64, __u64); 76 77 78 #endif /* _NILFS_DIRECT_H */ 79