fs/jfs/jfs_superblock.h

   1 /*
   2  *   Copyright (C) International Business Machines Corp., 2000-2003
   3  *
   4  *   This program is free software;  you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation; either version 2 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12  *   the GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program;  if not, write to the Free Software
  16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  */
  18 #ifndef _H_JFS_SUPERBLOCK
  19 #define _H_JFS_SUPERBLOCK
  20
  21 /*
  22  * make the magic number something a human could read
  23  */
  24 #define JFS_MAGIC       "JFS1"  /* Magic word */
  25
  26 #define JFS_VERSION     2       /* Version number: Version 2 */
  27
  28 #define LV_NAME_SIZE    11      /* MUST BE 11 for OS/2 boot sector */
  29
  30 /*
  31  *      aggregate superblock
  32  *
  33  * The name superblock is too close to super_block, so the name has been
  34  * changed to jfs_superblock.  The utilities are still using the old name.
  35  */
  36 struct jfs_superblock {
  37         char s_magic[4];        /* 4: magic number */
  38         __le32 s_version;       /* 4: version number */
  39
  40         __le64 s_size;          /* 8: aggregate size in hardware/LVM blocks;
  41                                  * VFS: number of blocks
  42                                  */
  43         __le32 s_bsize;         /* 4: aggregate block size in bytes;
  44                                  * VFS: fragment size
  45                                  */
  46         __le16 s_l2bsize;       /* 2: log2 of s_bsize */
  47         __le16 s_l2bfactor;     /* 2: log2(s_bsize/hardware block size) */
  48         __le32 s_pbsize;        /* 4: hardware/LVM block size in bytes */
  49         __le16 s_l2pbsize;      /* 2: log2 of s_pbsize */
  50         __le16 pad;             /* 2: padding necessary for alignment */
  51
  52         __le32 s_agsize;        /* 4: allocation group size in aggr. blocks */
  53
  54         __le32 s_flag;          /* 4: aggregate attributes:
  55                                  *    see jfs_filsys.h
  56                                  */
  57         __le32 s_state;         /* 4: mount/unmount/recovery state:
  58                                  *    see jfs_filsys.h
  59                                  */
  60         __le32 s_compress;              /* 4: > 0 if data compression */
  61
  62         pxd_t s_ait2;           /* 8: first extent of secondary
  63                                  *    aggregate inode table
  64                                  */
  65
  66         pxd_t s_aim2;           /* 8: first extent of secondary
  67                                  *    aggregate inode map
  68                                  */
  69         __le32 s_logdev;                /* 4: device address of log */
  70         __le32 s_logserial;     /* 4: log serial number at aggregate mount */
  71         pxd_t s_logpxd;         /* 8: inline log extent */
  72
  73         pxd_t s_fsckpxd;        /* 8: inline fsck work space extent */
  74
  75         struct timestruc_t s_time;      /* 8: time last updated */
  76
  77         __le32 s_fsckloglen;    /* 4: Number of filesystem blocks reserved for
  78                                  *    the fsck service log.
  79                                  *    N.B. These blocks are divided among the
  80                                  *         versions kept.  This is not a per
  81                                  *         version size.
  82                                  *    N.B. These blocks are included in the
  83                                  *         length field of s_fsckpxd.
  84                                  */
  85         s8 s_fscklog;           /* 1: which fsck service log is most recent
  86                                  *    0 => no service log data yet
  87                                  *    1 => the first one
  88                                  *    2 => the 2nd one
  89                                  */
  90         char s_fpack[11];       /* 11: file system volume name
  91                                  *     N.B. This must be 11 bytes to
  92                                  *          conform with the OS/2 BootSector
  93                                  *          requirements
  94                                  *          Only used when s_version is 1
  95                                  */
  96
  97         /* extendfs() parameter under s_state & FM_EXTENDFS */
  98         __le64 s_xsize;         /* 8: extendfs s_size */
  99         pxd_t s_xfsckpxd;       /* 8: extendfs fsckpxd */
 100         pxd_t s_xlogpxd;        /* 8: extendfs logpxd */
 101         /* - 128 byte boundary - */
 102
 103         char s_uuid[16];        /* 16: 128-bit uuid for volume */
 104         char s_label[16];       /* 16: volume label */
 105         char s_loguuid[16];     /* 16: 128-bit uuid for log device */
 106
 107 };
 108
 109 extern int readSuper(struct super_block *, struct buffer_head **);
 110 extern int updateSuper(struct super_block *, uint);
 111 extern void jfs_error(struct super_block *, const char *, ...);
 112
 113 #endif /*_H_JFS_SUPERBLOCK */