xref: /linux/fs/jfs/jfs_superblock.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 extern int jfs_mount(struct super_block *);
113 extern int jfs_mount_rw(struct super_block *, int);
114 extern int jfs_umount(struct super_block *);
115 extern int jfs_umount_rw(struct super_block *);
116 extern int jfs_extendfs(struct super_block *, s64, int);
117 
118 extern struct task_struct *jfsIOthread;
119 extern struct task_struct *jfsSyncThread;
120 
121 #endif /*_H_JFS_SUPERBLOCK */
122