fs/nilfs2/direct.h

   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 */