2 * linux/include/linux/jbd.h
4 * Written by Stephen C. Tweedie <sct@redhat.com>
6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
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.
12 * Definitions for transaction data structures for the buffer cache
13 * filesystem journaling support.
19 #include "jfs_compat.h"
21 #define jfs_debug jbd_debug
24 #define __FUNCTION__ ""
27 #define journal_oom_retry 1
30 #ifdef CONFIG_JBD_DEBUG
32 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
33 * consistency checks. By default we don't do this unless
34 * CONFIG_JBD_DEBUG is on.
36 #define JBD_EXPENSIVE_CHECKING
37 extern int journal_enable_debug;
39 #define jbd_debug(n, f, a...) \
41 if ((n) <= journal_enable_debug) { \
42 printk (KERN_DEBUG "(%s, %d): %s: ", \
43 __FILE__, __LINE__, __FUNCTION__); \
49 #if defined(__KERNEL__) || !defined(CONFIG_JBD_DEBUG)
50 #define jbd_debug(f, a...) /**/
52 extern int journal_enable_debug;
53 #define jbd_debug(n, f, a...) \
55 if ((n) <= journal_enable_debug) { \
56 printf("(%s, %d): %s: ", \
57 __FILE__, __LINE__, __func__); \
61 #endif /*__KERNEL__ */
63 #define jbd_debug(f, ...) /**/
67 #define jbd_debug(x) /* AIX doesn't do STDC */
70 extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry);
71 #define jbd_kmalloc(size, flags) \
72 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
73 #define jbd_rep_kmalloc(size, flags) \
74 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
76 #define JFS_MIN_JOURNAL_BLOCKS 1024
79 * Internal structures used by the logging mechanism:
82 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
89 * Descriptor block types:
92 #define JFS_DESCRIPTOR_BLOCK 1
93 #define JFS_COMMIT_BLOCK 2
94 #define JFS_SUPERBLOCK_V1 3
95 #define JFS_SUPERBLOCK_V2 4
96 #define JFS_REVOKE_BLOCK 5
99 * Standard header for all descriptor blocks:
101 typedef struct journal_header_s
111 #define JBD2_CRC32_CHKSUM 1
112 #define JBD2_MD5_CHKSUM 2
113 #define JBD2_SHA1_CHKSUM 3
114 #define JBD2_CRC32C_CHKSUM 4
116 #define JBD2_CRC32_CHKSUM_SIZE 4
118 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
120 * Commit block header for storing transactional checksums:
122 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
123 * fields are used to store a checksum of the descriptor and data blocks.
125 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
126 * field is used to store crc32c(uuid+commit_block). Each journal metadata
127 * block gets its own checksum, and data block checksums are stored in
128 * journal_block_tag (in the descriptor). The other h_chksum* fields are
131 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
132 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
135 * Checksum v1, v2, and v3 are mutually exclusive features.
137 struct commit_header {
141 unsigned char h_chksum_type;
142 unsigned char h_chksum_size;
143 unsigned char h_padding[2];
144 __u32 h_chksum[JBD2_CHECKSUM_BYTES];
150 * The block tag: used to describe a single buffer in the journal
152 typedef struct journal_block_tag3_s
154 __u32 t_blocknr; /* The on-disk block number */
155 __u32 t_flags; /* See below */
156 __u32 t_blocknr_high; /* most-significant high 32bits. */
157 __u32 t_checksum; /* crc32c(uuid+seq+block) */
158 } journal_block_tag3_t;
160 typedef struct journal_block_tag_s
162 __u32 t_blocknr; /* The on-disk block number */
163 __u16 t_checksum; /* truncated crc32c(uuid+seq+block) */
164 __u16 t_flags; /* See below */
165 __u32 t_blocknr_high; /* most-significant high 32bits. */
166 } journal_block_tag_t;
168 /* Tail of descriptor block, for checksumming */
169 struct journal_block_tail {
174 * The revoke descriptor: used on disk to describe a series of blocks to
175 * be revoked from the log
177 typedef struct journal_revoke_header_s
179 journal_header_t r_header;
180 int r_count; /* Count of bytes used in the block */
181 } journal_revoke_header_t;
183 /* Tail of revoke block, for checksumming */
184 struct journal_revoke_tail {
188 /* Definitions for the journal tag flags word: */
189 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
190 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
191 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
192 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
196 #define JFS_USERS_MAX 48
197 #define JFS_USERS_SIZE (UUID_SIZE * JFS_USERS_MAX)
199 * The journal superblock. All fields are in big-endian byte order.
201 typedef struct journal_superblock_s
204 journal_header_t s_header;
207 /* Static information describing the journal */
208 __u32 s_blocksize; /* journal device blocksize */
209 __u32 s_maxlen; /* total blocks in journal file */
210 __u32 s_first; /* first block of log information */
213 /* Dynamic information describing the current state of the log */
214 __u32 s_sequence; /* first commit ID expected in log */
215 __u32 s_start; /* blocknr of start of log */
218 /* Error value, as set by journal_abort(). */
222 /* Remaining fields are only valid in a version-2 superblock */
223 __u32 s_feature_compat; /* compatible feature set */
224 __u32 s_feature_incompat; /* incompatible feature set */
225 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
227 __u8 s_uuid[16]; /* 128-bit uuid for journal */
230 __u32 s_nr_users; /* Nr of filesystems sharing log */
232 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
235 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
236 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
239 __u8 s_checksum_type; /* checksum type */
242 __u32 s_checksum; /* crc32c(superblock) */
245 __u8 s_users[JFS_USERS_SIZE]; /* ids of all fs'es sharing the log */
248 } journal_superblock_t;
250 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
251 ((j)->j_format_version >= 2 && \
252 ((j)->j_superblock->s_feature_compat & ext2fs_cpu_to_be32((mask))))
253 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
254 ((j)->j_format_version >= 2 && \
255 ((j)->j_superblock->s_feature_ro_compat & ext2fs_cpu_to_be32((mask))))
256 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
257 ((j)->j_format_version >= 2 && \
258 ((j)->j_superblock->s_feature_incompat & ext2fs_cpu_to_be32((mask))))
260 #define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001
262 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
263 #define JFS_FEATURE_INCOMPAT_64BIT 0x00000002
264 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
265 #define JFS_FEATURE_INCOMPAT_CSUM_V2 0x00000008
266 #define JFS_FEATURE_INCOMPAT_CSUM_V3 0x00000010
268 /* Features known to this kernel version: */
269 #define JFS_KNOWN_COMPAT_FEATURES 0
270 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
271 #define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE|\
272 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT|\
273 JFS_FEATURE_INCOMPAT_64BIT|\
274 JFS_FEATURE_INCOMPAT_CSUM_V2|\
275 JFS_FEATURE_INCOMPAT_CSUM_V3)
277 #ifdef NO_INLINE_FUNCS
278 extern size_t journal_tag_bytes(journal_t *journal);
279 extern int journal_has_csum_v2or3(journal_t *journal);
280 extern int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused));
281 extern int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused));
284 #if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
285 #ifdef E2FSCK_INCLUDE_INLINE_FUNCS
286 #if (__STDC_VERSION__ >= 199901L)
287 #define _INLINE_ extern inline
289 #define _INLINE_ inline
291 #else /* !E2FSCK_INCLUDE_INLINE FUNCS */
292 #if (__STDC_VERSION__ >= 199901L)
293 #define _INLINE_ inline
296 #define _INLINE_ extern __inline__
297 #else /* For Watcom C */
298 #define _INLINE_ extern inline
299 #endif /* __GNUC__ */
300 #endif /* __STDC_VERSION__ >= 199901L */
301 #endif /* INCLUDE_INLINE_FUNCS */
303 /* journal feature predicate functions */
304 #define JFS_FEATURE_COMPAT_FUNCS(name, flagname) \
305 _INLINE_ int jfs_has_feature_##name(journal_t *j); \
306 _INLINE_ int jfs_has_feature_##name(journal_t *j) \
308 return ((j)->j_format_version >= 2 && \
309 ((j)->j_superblock->s_feature_compat & \
310 ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname)) != 0); \
312 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
313 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
315 (j)->j_superblock->s_feature_compat |= \
316 ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname); \
318 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
319 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
321 (j)->j_superblock->s_feature_compat &= \
322 ~ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname); \
325 #define JFS_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
326 _INLINE_ int jfs_has_feature_##name(journal_t *j); \
327 _INLINE_ int jfs_has_feature_##name(journal_t *j) \
329 return ((j)->j_format_version >= 2 && \
330 ((j)->j_superblock->s_feature_ro_compat & \
331 ext2fs_cpu_to_be32(JFS_FEATURE_RO_COMPAT_##flagname)) != 0); \
333 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
334 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
336 (j)->j_superblock->s_feature_ro_compat |= \
337 ext2fs_cpu_to_be32(JFS_FEATURE_RO_COMPAT_##flagname); \
339 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
340 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
342 (j)->j_superblock->s_feature_ro_compat &= \
343 ~ext2fs_cpu_to_be32(JFS_FEATURE_RO_COMPAT_##flagname); \
346 #define JFS_FEATURE_INCOMPAT_FUNCS(name, flagname) \
347 _INLINE_ int jfs_has_feature_##name(journal_t *j); \
348 _INLINE_ int jfs_has_feature_##name(journal_t *j) \
350 return ((j)->j_format_version >= 2 && \
351 ((j)->j_superblock->s_feature_incompat & \
352 ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname)) != 0); \
354 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
355 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
357 (j)->j_superblock->s_feature_incompat |= \
358 ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname); \
360 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
361 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
363 (j)->j_superblock->s_feature_incompat &= \
364 ~ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname); \
368 #define JFS_FEATURE_COMPAT_FUNCS(name, flagname) \
369 extern int jfs_has_feature_##name(journal_t *j); \
370 extern void jfs_set_feature_##name(journal_t *j); \
371 extern void jfs_clear_feature_##name(journal_t *j);
373 #define JFS_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
374 extern int jfs_has_feature_##name(journal_t *j); \
375 extern void jfs_set_feature_##name(journal_t *j); \
376 extern void jfs_clear_feature_##name(journal_t *j);
378 #define JFS_FEATURE_INCOMPAT_FUNCS(name, flagname) \
379 extern int jfs_has_feature_##name(journal_t *j); \
380 extern void jfs_set_feature_##name(journal_t *j); \
381 extern void jfs_clear_feature_##name(journal_t *j);
383 #endif /* (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS)) */
385 JFS_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
387 JFS_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
388 JFS_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
389 JFS_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
390 JFS_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
391 JFS_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
393 #if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
395 * helper functions to deal with 32 or 64bit block numbers.
397 _INLINE_ size_t journal_tag_bytes(journal_t *journal)
401 if (jfs_has_feature_csum3(journal))
402 return sizeof(journal_block_tag3_t);
404 sz = sizeof(journal_block_tag_t);
406 if (jfs_has_feature_csum2(journal))
409 if (jfs_has_feature_64bit(journal))
412 return sz - sizeof(__u32);
415 _INLINE_ int journal_has_csum_v2or3(journal_t *journal)
417 if (jfs_has_feature_csum2(journal) || jfs_has_feature_csum3(journal))
423 /* Comparison functions for transaction IDs: perform comparisons using
424 * modulo arithmetic so that they work over sequence number wraps. */
426 _INLINE_ int tid_gt(tid_t x, tid_t y)
428 int difference = (x - y);
429 return (difference > 0);
432 _INLINE_ int tid_geq(tid_t x, tid_t y)
434 int difference = (x - y);
435 return (difference >= 0);
437 #endif /* (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS)) */
441 extern int journal_blocks_per_page(struct inode *inode);
444 * Definitions which augment the buffer_head layer
447 /* journaling buffer types */
448 #define BJ_None 0 /* Not journaled */
449 #define BJ_SyncData 1 /* Normal data: flush before commit */
450 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
451 #define BJ_Metadata 3 /* Normal journaled metadata */
452 #define BJ_Forget 4 /* Buffer superceded by this transaction */
453 #define BJ_IO 5 /* Buffer is for temporary IO use */
454 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
455 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
456 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
459 extern int jbd_blocks_per_page(struct inode *inode);
461 #endif /* _LINUX_JBD_H */