xref: /linux/fs/jfs/jfs_superblock.h (revision 1a59d1b8)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *   Copyright (C) International Business Machines Corp., 2000-2003
4  */
5 #ifndef	_H_JFS_SUPERBLOCK
6 #define _H_JFS_SUPERBLOCK
7 
8 #include <linux/uuid.h>
9 
10 /*
11  * make the magic number something a human could read
12  */
13 #define JFS_MAGIC	"JFS1"	/* Magic word */
14 
15 #define JFS_VERSION	2	/* Version number: Version 2 */
16 
17 #define LV_NAME_SIZE	11	/* MUST BE 11 for OS/2 boot sector */
18 
19 /*
20  *	aggregate superblock
21  *
22  * The name superblock is too close to super_block, so the name has been
23  * changed to jfs_superblock.  The utilities are still using the old name.
24  */
25 struct jfs_superblock {
26 	char s_magic[4];	/* 4: magic number */
27 	__le32 s_version;	/* 4: version number */
28 
29 	__le64 s_size;		/* 8: aggregate size in hardware/LVM blocks;
30 				 * VFS: number of blocks
31 				 */
32 	__le32 s_bsize;		/* 4: aggregate block size in bytes;
33 				 * VFS: fragment size
34 				 */
35 	__le16 s_l2bsize;	/* 2: log2 of s_bsize */
36 	__le16 s_l2bfactor;	/* 2: log2(s_bsize/hardware block size) */
37 	__le32 s_pbsize;	/* 4: hardware/LVM block size in bytes */
38 	__le16 s_l2pbsize;	/* 2: log2 of s_pbsize */
39 	__le16 pad;		/* 2: padding necessary for alignment */
40 
41 	__le32 s_agsize;	/* 4: allocation group size in aggr. blocks */
42 
43 	__le32 s_flag;		/* 4: aggregate attributes:
44 				 *    see jfs_filsys.h
45 				 */
46 	__le32 s_state;		/* 4: mount/unmount/recovery state:
47 				 *    see jfs_filsys.h
48 				 */
49 	__le32 s_compress;		/* 4: > 0 if data compression */
50 
51 	pxd_t s_ait2;		/* 8: first extent of secondary
52 				 *    aggregate inode table
53 				 */
54 
55 	pxd_t s_aim2;		/* 8: first extent of secondary
56 				 *    aggregate inode map
57 				 */
58 	__le32 s_logdev;		/* 4: device address of log */
59 	__le32 s_logserial;	/* 4: log serial number at aggregate mount */
60 	pxd_t s_logpxd;		/* 8: inline log extent */
61 
62 	pxd_t s_fsckpxd;	/* 8: inline fsck work space extent */
63 
64 	struct timestruc_t s_time;	/* 8: time last updated */
65 
66 	__le32 s_fsckloglen;	/* 4: Number of filesystem blocks reserved for
67 				 *    the fsck service log.
68 				 *    N.B. These blocks are divided among the
69 				 *         versions kept.  This is not a per
70 				 *         version size.
71 				 *    N.B. These blocks are included in the
72 				 *         length field of s_fsckpxd.
73 				 */
74 	s8 s_fscklog;		/* 1: which fsck service log is most recent
75 				 *    0 => no service log data yet
76 				 *    1 => the first one
77 				 *    2 => the 2nd one
78 				 */
79 	char s_fpack[11];	/* 11: file system volume name
80 				 *     N.B. This must be 11 bytes to
81 				 *          conform with the OS/2 BootSector
82 				 *          requirements
83 				 *          Only used when s_version is 1
84 				 */
85 
86 	/* extendfs() parameter under s_state & FM_EXTENDFS */
87 	__le64 s_xsize;		/* 8: extendfs s_size */
88 	pxd_t s_xfsckpxd;	/* 8: extendfs fsckpxd */
89 	pxd_t s_xlogpxd;	/* 8: extendfs logpxd */
90 	uuid_t s_uuid;		/* 16: 128-bit uuid for volume */
91 	char s_label[16];	/* 16: volume label */
92 	uuid_t s_loguuid;	/* 16: 128-bit uuid for log device */
93 
94 };
95 
96 extern int readSuper(struct super_block *, struct buffer_head **);
97 extern int updateSuper(struct super_block *, uint);
98 __printf(2, 3)
99 extern void jfs_error(struct super_block *, const char *, ...);
100 extern int jfs_mount(struct super_block *);
101 extern int jfs_mount_rw(struct super_block *, int);
102 extern int jfs_umount(struct super_block *);
103 extern int jfs_umount_rw(struct super_block *);
104 extern int jfs_extendfs(struct super_block *, s64, int);
105 
106 extern struct task_struct *jfsIOthread;
107 extern struct task_struct *jfsSyncThread;
108 
109 #endif /*_H_JFS_SUPERBLOCK */
110