1 /*
2 * Copyright (c) International Business Machines Corp., 2000
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 3 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, see <http://www.gnu.org/licenses/>.
16 *
17 */
18 #ifndef _H_JFS_SUPERBLOCK
19 #define _H_JFS_SUPERBLOCK
20 /*
21 * jfs_superblock.h
22 */
23
24 /*
25 * make the magic number something a human could read
26 */
27 #define JFS_MAGIC "JFS1" /* Magic word: Version 1 */
28
29 #define JFS_VERSION 1 /* Version number: Version 1 */
30
31 #define LV_NAME_SIZE 11 /* MUST BE 11 for OS/2 boot sector */
32
33 /*
34 * aggregate superblock
35 *
36 * The name superblock is too close to super_block, so the name has been
37 * changed to jfs_superblock. The utilities are still using the old name.
38 */
39 #ifdef _JFS_UTILITY
40 struct superblock
41 #else
42 struct jfs_superblock
43 #endif
44 {
45 char s_magic[4]; /* 4: magic number */
46 u32 s_version; /* 4: version number */
47
48 s64 s_size; /* 8: aggregate size in hardware/LVM blocks;
49 * VFS: number of blocks
50 */
51 s32 s_bsize; /* 4: aggregate block size in bytes;
52 * VFS: fragment size
53 */
54 s16 s_l2bsize; /* 2: log2 of s_bsize */
55 s16 s_l2bfactor; /* 2: log2(s_bsize/hardware block size) */
56 s32 s_pbsize; /* 4: hardware/LVM block size in bytes */
57 s16 s_l2pbsize; /* 2: log2 of s_pbsize */
58 s16 pad; /* 2: padding necessary for alignment */
59
60 u32 s_agsize; /* 4: allocation group size in aggr. blocks */
61
62 u32 s_flag; /* 4: aggregate attributes:
63 * see jfs_filsys.h
64 */
65 u32 s_state; /* 4: mount/unmount/recovery state:
66 * see jfs_filsys.h
67 */
68 s32 s_compress; /* 4: > 0 if data compression */
69
70 pxd_t s_ait2; /* 8: first extent of secondary
71 * aggregate inode table
72 */
73
74 pxd_t s_aim2; /* 8: first extent of secondary
75 * aggregate inode map
76 */
77 u32 s_logdev; /* 4: device address of log */
78 s32 s_logserial; /* 4: log serial number at aggregate mount */
79 pxd_t s_logpxd; /* 8: inline log extent */
80
81 pxd_t s_fsckpxd; /* 8: inline fsck work space extent */
82
83 struct timestruc_t s_time; /* 8: time last updated */
84
85 s32 s_fsckloglen; /* 4: Number of file system blocks reserved for
86 * the fsck service log.
87 * N.B. These blocks are divided among the
88 * versions kept. This is not a per
89 * version size.
90 * N.B. These blocks are included in the
91 * length field of s_fsckpxd.
92 */
93 s8 s_fscklog; /* 1: which fsck service log is most recent
94 * 0 => no service log data yet
95 * 1 => the first one
96 * 2 => the 2nd one
97 */
98 char s_fpack[11]; /* 11: file system volume name
99 * N.B. This must be 11 bytes to
100 * conform with the OS/2 BootSector
101 * requirements
102 */
103
104 /* extendfs() parameter under s_state & FM_EXTENDFS */
105 s64 s_xsize; /* 8: extendfs s_size */
106 pxd_t s_xfsckpxd; /* 8: extendfs fsckpxd */
107 pxd_t s_xlogpxd; /* 8: extendfs logpxd */
108 /* - 128 byte boundary - */
109
110 /*
111 * DFS VFS support (preliminary)
112 */
113 char s_attach; /* 1: VFS: flag: set when aggregate is attached
114 */
115 u8 rsrvd4[7]; /* 7: reserved - set to 0 */
116
117 u64 totalUsable; /* 8: VFS: total of 1K blocks which are
118 * available to "normal" (non-root) users.
119 */
120 u64 minFree; /* 8: VFS: # of 1K blocks held in reserve for
121 * exclusive use of root. This value can be 0,
122 * and if it is then totalUsable will be equal
123 * to # of blocks in aggregate. I believe this
124 * means that minFree + totalUsable = # blocks.
125 * In that case, we don't need to store both
126 * totalUsable and minFree since we can compute
127 * one from the other. I would guess minFree
128 * would be the one we should store, and
129 * totalUsable would be the one we should
130 * compute. (Just a guess...)
131 */
132
133 u64 realFree; /* 8: VFS: # of free 1K blocks can be used by
134 * "normal" users. It may be this is something
135 * we should compute when asked for instead of
136 * storing in the superblock. I don't know how
137 * often this information is needed.
138 */
139 /*
140 * graffiti area
141 */
142 };
143
144 #endif /*_H_JFS_SUPERBLOCK */