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_node - direct node
  35  * @dn_flags: flags
  36  * @dn_pad: padding
  37  */
  38 struct nilfs_direct_node {
  39         __u8 dn_flags;
  40         __u8 pad[7];
  41 };
  42
  43 /**
  44  * struct nilfs_direct - direct mapping
  45  * @d_bmap: bmap structure
  46  */
  47 struct nilfs_direct {
  48         struct nilfs_bmap d_bmap;
  49 };
  50
  51
  52 #define NILFS_DIRECT_NBLOCKS    (NILFS_BMAP_SIZE / sizeof(__le64) - 1)
  53 #define NILFS_DIRECT_KEY_MIN    0
  54 #define NILFS_DIRECT_KEY_MAX    (NILFS_DIRECT_NBLOCKS - 1)
  55
  56
  57 int nilfs_direct_init(struct nilfs_bmap *);
  58 int nilfs_direct_delete_and_convert(struct nilfs_bmap *, __u64, __u64 *,
  59                                     __u64 *, int);
  60
  61
  62 #endif  /* _NILFS_DIRECT_H */