sys/fs/efs/efs_sb.h

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 2006 Stephen M. Rumble <rumble@ephemeral.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /*
  20  * See IRIX efs(4)
  21  */
  22
  23 #ifndef _FS_EFS_EFS_SB_H_
  24 #define _FS_EFS_EFS_SB_H_
  25
  26 /*
  27  * EFS superblock (92 bytes)
  28  *
  29  * Notes:
  30  *   [0] - Values can either be EFS_SB_MAGIC, or EFS_SB_NEWMAGIC (IRIX 3.3+).
  31  *   [1] - Only used in a grown filesystem. Original bitmap is unused.
  32  *   [2] - Only exists in IRIX3.3+. (XXX - IRIX man pages say 3.3+ fsck
  33  *         creates a replicated superblock if space free. Does it update magic?)
  34  *   [3] - According to IRIX kernel elf headers, two checksum routines exist.
  35  *   [4] - New at some point (in IRIX 5, but apparently not in IRIX 4).
  36  */
  37 struct efs_sb {
  38         int32_t         sb_size;        /* 0:   fs size incl. bb 0 (in bb) */
  39         int32_t         sb_firstcg;     /* 4:   first cg offset (in bb) */
  40         int32_t         sb_cgfsize;     /* 8:   cg size (in bb) */
  41         int16_t         sb_cgisize;     /* 12:  inodes/cg (in bb) */
  42         int16_t         sb_sectors;     /* 14:  geom: sectors/track */
  43         int16_t         sb_heads;       /* 16:  geom: heads/cylinder (unused) */
  44         int16_t         sb_ncg;         /* 18:  num of cg's in the filesystem */
  45         int16_t         sb_dirty;       /* 20:  non-0 indicates fsck required */
  46         int16_t         sb_pad0;        /* 22:  */
  47         int32_t         sb_time;        /* 24:  superblock ctime */
  48         int32_t         sb_magic;       /* 28:  magic [0] */
  49         char            sb_fname[6];    /* 32:  name of filesystem */
  50         char            sb_fpack[6];    /* 38:  name of filesystem pack */
  51         int32_t         sb_bmsize;      /* 44:  bitmap size (in bytes) */
  52         int32_t         sb_tfree;       /* 48:  total free data blocks */
  53         int32_t         sb_tinode;      /* 52:  total free inodes */
  54         int32_t         sb_bmblock;     /* 56:  bitmap offset (grown fs) [1] */
  55         int32_t         sb_replsb;      /* 62:  repl. superblock offset [2] */
  56         int32_t         sb_lastinode;   /* 64:  last allocated inode [4] */
  57         int8_t          sb_spare[20];   /* 68:  unused */
  58         int32_t         sb_checksum;    /* 88:  checksum (all above) [3] */
  59 } __packed;
  60
  61 #define EFS_SB_SIZE             (sizeof(struct efs_sb))
  62 #define EFS_SB_CHECKSUM_SIZE    (EFS_SB_SIZE - 4)
  63
  64 #define EFS_SB_MAGIC            0x00072959      /* original, ungrown layout */
  65 #define EFS_SB_NEWMAGIC         0x0007295A      /* grown fs (IRIX >= 3.3) */
  66
  67 /* sb_dirty values */
  68 #define EFS_SB_CLEAN            0               /* filesystem is clean */
  69
  70 #endif /* !_FS_EFS_EFS_SB_H_ */