[821] | 1 | /*
|
---|
| 2 | * linux/include/linux/jbd.h
|
---|
| 3 | *
|
---|
| 4 | * Written by Stephen C. Tweedie <sct@redhat.com>
|
---|
| 5 | *
|
---|
| 6 | * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
|
---|
| 7 | *
|
---|
| 8 | * This file is part of the Linux kernel and is made available under
|
---|
| 9 | * the terms of the GNU General Public License, version 2, or at your
|
---|
| 10 | * option, any later version, incorporated herein by reference.
|
---|
| 11 | *
|
---|
| 12 | * Definitions for transaction data structures for the buffer cache
|
---|
| 13 | * filesystem journaling support.
|
---|
| 14 | */
|
---|
| 15 |
|
---|
| 16 | #ifndef _LINUX_JBD_H
|
---|
| 17 | #define _LINUX_JBD_H
|
---|
| 18 |
|
---|
| 19 | #include <sys/types.h>
|
---|
| 20 | #include <linux/types.h>
|
---|
| 21 | #include "ext2fs.h"
|
---|
| 22 |
|
---|
| 23 | /*
|
---|
| 24 | * Standard header for all descriptor blocks:
|
---|
| 25 | */
|
---|
| 26 |
|
---|
| 27 | typedef struct journal_header_s
|
---|
| 28 | {
|
---|
| 29 | __u32 h_magic;
|
---|
| 30 | __u32 h_blocktype;
|
---|
| 31 | __u32 h_sequence;
|
---|
| 32 | } journal_header_t;
|
---|
| 33 |
|
---|
| 34 | /*
|
---|
| 35 | * This is the global e2fsck structure.
|
---|
| 36 | */
|
---|
| 37 | typedef struct e2fsck_struct *e2fsck_t;
|
---|
| 38 |
|
---|
| 39 |
|
---|
| 40 | struct inode {
|
---|
| 41 | e2fsck_t i_ctx;
|
---|
| 42 | ext2_ino_t i_ino;
|
---|
| 43 | struct ext2_inode i_ext2;
|
---|
| 44 | };
|
---|
| 45 |
|
---|
| 46 |
|
---|
| 47 | /*
|
---|
| 48 | * The journal superblock. All fields are in big-endian byte order.
|
---|
| 49 | */
|
---|
| 50 | typedef struct journal_superblock_s
|
---|
| 51 | {
|
---|
| 52 | /* 0x0000 */
|
---|
| 53 | journal_header_t s_header;
|
---|
| 54 |
|
---|
| 55 | /* 0x000C */
|
---|
| 56 | /* Static information describing the journal */
|
---|
| 57 | __u32 s_blocksize; /* journal device blocksize */
|
---|
| 58 | __u32 s_maxlen; /* total blocks in journal file */
|
---|
| 59 | __u32 s_first; /* first block of log information */
|
---|
| 60 |
|
---|
| 61 | /* 0x0018 */
|
---|
| 62 | /* Dynamic information describing the current state of the log */
|
---|
| 63 | __u32 s_sequence; /* first commit ID expected in log */
|
---|
| 64 | __u32 s_start; /* blocknr of start of log */
|
---|
| 65 |
|
---|
| 66 | /* 0x0020 */
|
---|
| 67 | /* Error value, as set by journal_abort(). */
|
---|
| 68 | __s32 s_errno;
|
---|
| 69 |
|
---|
| 70 | /* 0x0024 */
|
---|
| 71 | /* Remaining fields are only valid in a version-2 superblock */
|
---|
| 72 | __u32 s_feature_compat; /* compatible feature set */
|
---|
| 73 | __u32 s_feature_incompat; /* incompatible feature set */
|
---|
| 74 | __u32 s_feature_ro_compat; /* readonly-compatible feature set */
|
---|
| 75 | /* 0x0030 */
|
---|
| 76 | __u8 s_uuid[16]; /* 128-bit uuid for journal */
|
---|
| 77 |
|
---|
| 78 | /* 0x0040 */
|
---|
| 79 | __u32 s_nr_users; /* Nr of filesystems sharing log */
|
---|
| 80 |
|
---|
| 81 | __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
|
---|
| 82 |
|
---|
| 83 | /* 0x0048 */
|
---|
| 84 | __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
|
---|
| 85 | __u32 s_max_trans_data; /* Limit of data blocks per trans. */
|
---|
| 86 |
|
---|
| 87 | /* 0x0050 */
|
---|
| 88 | __u32 s_padding[44];
|
---|
| 89 |
|
---|
| 90 | /* 0x0100 */
|
---|
| 91 | __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
|
---|
| 92 | /* 0x0400 */
|
---|
| 93 | } journal_superblock_t;
|
---|
| 94 |
|
---|
| 95 |
|
---|
| 96 | extern int journal_blocks_per_page(struct inode *inode);
|
---|
| 97 | extern int jbd_blocks_per_page(struct inode *inode);
|
---|
| 98 |
|
---|
| 99 | #define JFS_MIN_JOURNAL_BLOCKS 1024
|
---|
| 100 |
|
---|
| 101 |
|
---|
| 102 | /*
|
---|
| 103 | * Internal structures used by the logging mechanism:
|
---|
| 104 | */
|
---|
| 105 |
|
---|
| 106 | #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
|
---|
| 107 |
|
---|
| 108 | /*
|
---|
| 109 | * Descriptor block types:
|
---|
| 110 | */
|
---|
| 111 |
|
---|
| 112 | #define JFS_DESCRIPTOR_BLOCK 1
|
---|
| 113 | #define JFS_COMMIT_BLOCK 2
|
---|
| 114 | #define JFS_SUPERBLOCK_V1 3
|
---|
| 115 | #define JFS_SUPERBLOCK_V2 4
|
---|
| 116 | #define JFS_REVOKE_BLOCK 5
|
---|
| 117 |
|
---|
| 118 | /*
|
---|
| 119 | * The block tag: used to describe a single buffer in the journal
|
---|
| 120 | */
|
---|
| 121 | typedef struct journal_block_tag_s
|
---|
| 122 | {
|
---|
| 123 | __u32 t_blocknr; /* The on-disk block number */
|
---|
| 124 | __u32 t_flags; /* See below */
|
---|
| 125 | } journal_block_tag_t;
|
---|
| 126 |
|
---|
| 127 | /*
|
---|
| 128 | * The revoke descriptor: used on disk to describe a series of blocks to
|
---|
| 129 | * be revoked from the log
|
---|
| 130 | */
|
---|
| 131 | typedef struct journal_revoke_header_s
|
---|
| 132 | {
|
---|
| 133 | journal_header_t r_header;
|
---|
| 134 | int r_count; /* Count of bytes used in the block */
|
---|
| 135 | } journal_revoke_header_t;
|
---|
| 136 |
|
---|
| 137 |
|
---|
| 138 | /* Definitions for the journal tag flags word: */
|
---|
| 139 | #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
|
---|
| 140 | #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
|
---|
| 141 | #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
|
---|
| 142 | #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
|
---|
| 143 |
|
---|
| 144 |
|
---|
| 145 |
|
---|
| 146 |
|
---|
| 147 | #define JFS_HAS_COMPAT_FEATURE(j,mask) \
|
---|
| 148 | ((j)->j_format_version >= 2 && \
|
---|
| 149 | ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
|
---|
| 150 | #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
|
---|
| 151 | ((j)->j_format_version >= 2 && \
|
---|
| 152 | ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
|
---|
| 153 | #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
|
---|
| 154 | ((j)->j_format_version >= 2 && \
|
---|
| 155 | ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
|
---|
| 156 |
|
---|
| 157 | #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
|
---|
| 158 |
|
---|
| 159 | /* Features known to this kernel version: */
|
---|
| 160 | #define JFS_KNOWN_COMPAT_FEATURES 0
|
---|
| 161 | #define JFS_KNOWN_ROCOMPAT_FEATURES 0
|
---|
| 162 | #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
|
---|
| 163 |
|
---|
| 164 | /* Comparison functions for transaction IDs: perform comparisons using
|
---|
| 165 | * modulo arithmetic so that they work over sequence number wraps. */
|
---|
| 166 |
|
---|
| 167 |
|
---|
| 168 | /*
|
---|
| 169 | * Definitions which augment the buffer_head layer
|
---|
| 170 | */
|
---|
| 171 |
|
---|
| 172 | /* journaling buffer types */
|
---|
| 173 | #define BJ_None 0 /* Not journaled */
|
---|
| 174 | #define BJ_SyncData 1 /* Normal data: flush before commit */
|
---|
| 175 | #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
|
---|
| 176 | #define BJ_Metadata 3 /* Normal journaled metadata */
|
---|
| 177 | #define BJ_Forget 4 /* Buffer superceded by this transaction */
|
---|
| 178 | #define BJ_IO 5 /* Buffer is for temporary IO use */
|
---|
| 179 | #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
|
---|
| 180 | #define BJ_LogCtl 7 /* Buffer contains log descriptors */
|
---|
| 181 | #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
|
---|
| 182 | #define BJ_Types 9
|
---|
| 183 |
|
---|
| 184 |
|
---|
| 185 | struct kdev_s {
|
---|
| 186 | e2fsck_t k_ctx;
|
---|
| 187 | int k_dev;
|
---|
| 188 | };
|
---|
| 189 |
|
---|
| 190 | typedef struct kdev_s *kdev_t;
|
---|
| 191 | typedef unsigned int tid_t;
|
---|
| 192 |
|
---|
| 193 | struct journal_s
|
---|
| 194 | {
|
---|
| 195 | unsigned long j_flags;
|
---|
| 196 | int j_errno;
|
---|
| 197 | struct buffer_head * j_sb_buffer;
|
---|
| 198 | struct journal_superblock_s *j_superblock;
|
---|
| 199 | int j_format_version;
|
---|
| 200 | unsigned long j_head;
|
---|
| 201 | unsigned long j_tail;
|
---|
| 202 | unsigned long j_free;
|
---|
| 203 | unsigned long j_first, j_last;
|
---|
| 204 | kdev_t j_dev;
|
---|
| 205 | kdev_t j_fs_dev;
|
---|
| 206 | int j_blocksize;
|
---|
| 207 | unsigned int j_blk_offset;
|
---|
| 208 | unsigned int j_maxlen;
|
---|
| 209 | struct inode * j_inode;
|
---|
| 210 | tid_t j_tail_sequence;
|
---|
| 211 | tid_t j_transaction_sequence;
|
---|
| 212 | __u8 j_uuid[16];
|
---|
| 213 | struct jbd_revoke_table_s *j_revoke;
|
---|
| 214 | };
|
---|
| 215 |
|
---|
| 216 | typedef struct journal_s journal_t;
|
---|
| 217 |
|
---|
| 218 | extern int journal_recover (journal_t *journal);
|
---|
| 219 | extern int journal_skip_recovery (journal_t *);
|
---|
| 220 |
|
---|
| 221 | /* Primary revoke support */
|
---|
| 222 | extern int journal_init_revoke(journal_t *, int);
|
---|
| 223 | extern void journal_destroy_revoke_caches(void);
|
---|
| 224 | extern int journal_init_revoke_caches(void);
|
---|
| 225 |
|
---|
| 226 | /* Recovery revoke support */
|
---|
| 227 | extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
|
---|
| 228 | extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
|
---|
| 229 | extern void journal_clear_revoke(journal_t *);
|
---|
| 230 | extern void journal_brelse_array(struct buffer_head *b[], int n);
|
---|
| 231 |
|
---|
| 232 | extern void journal_destroy_revoke(journal_t *);
|
---|
| 233 |
|
---|
| 234 |
|
---|
| 235 | #endif /* _LINUX_JBD_H */
|
---|