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 "jfs_compat.h"
20 #define JFS_DEBUG
21 #define jfs_debug jbd_debug
22
23 #ifndef __GNUC__
24 #define __FUNCTION__ ""
25 #endif
26
27 #define journal_oom_retry 1
28
29 #ifdef __STDC__
30 #ifdef CONFIG_JBD_DEBUG
31 /*
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.
35 */
36 #define JBD_EXPENSIVE_CHECKING
37 extern int journal_enable_debug;
38
39 #define jbd_debug(n, f, a...) \
40 do { \
41 if ((n) <= journal_enable_debug) { \
42 printk (KERN_DEBUG "(%s, %d): %s: ", \
43 __FILE__, __LINE__, __FUNCTION__); \
44 printk (f, ## a); \
45 } \
46 } while (0)
47 #else
48 #ifdef __GNUC__
49 #if defined(__KERNEL__) || !defined(CONFIG_JBD_DEBUG)
50 #define jbd_debug(f, a...) /**/
51 #else
52 extern int journal_enable_debug;
53 #define jbd_debug(n, f, a...) \
54 do { \
55 if ((n) <= journal_enable_debug) { \
56 printf("(%s, %d): %s: ", \
57 __FILE__, __LINE__, __func__); \
58 printf(f, ## a); \
59 } \
60 } while (0)
61 #endif /*__KERNEL__ */
62 #else
63 #define jbd_debug(f, ...) /**/
64 #endif
65 #endif
66 #else
67 #define jbd_debug(x) /* AIX doesn't do STDC */
68 #endif
69
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)
75
76 #define JFS_MIN_JOURNAL_BLOCKS 1024
77
78 /*
79 * Internal structures used by the logging mechanism:
80 */
81
82 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
83
84 /*
85 * On-disk structures
86 */
87
88 /*
89 * Descriptor block types:
90 */
91
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
97
98 /*
99 * Standard header for all descriptor blocks:
100 */
101 typedef struct journal_header_s
102 {
103 __u32 h_magic;
104 __u32 h_blocktype;
105 __u32 h_sequence;
106 } journal_header_t;
107
108 /*
109 * Checksum types.
110 */
111 #define JBD2_CRC32_CHKSUM 1
112 #define JBD2_MD5_CHKSUM 2
113 #define JBD2_SHA1_CHKSUM 3
114 #define JBD2_CRC32C_CHKSUM 4
115
116 #define JBD2_CRC32_CHKSUM_SIZE 4
117
118 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
119 /*
120 * Commit block header for storing transactional checksums:
121 *
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.
124 *
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
129 * not used.
130 *
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
133 * is the same as v2.
134 *
135 * Checksum v1, v2, and v3 are mutually exclusive features.
136 */
137 struct commit_header {
138 __u32 h_magic;
139 __u32 h_blocktype;
140 __u32 h_sequence;
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];
145 __u64 h_commit_sec;
146 __u32 h_commit_nsec;
147 };
148
149 /*
150 * The block tag: used to describe a single buffer in the journal
151 */
152 typedef struct journal_block_tag3_s
153 {
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;
159
160 typedef struct journal_block_tag_s
161 {
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;
167
168 /* Tail of descriptor block, for checksumming */
169 struct journal_block_tail {
170 __be32 t_checksum;
171 };
172
173 /*
174 * The revoke descriptor: used on disk to describe a series of blocks to
175 * be revoked from the log
176 */
177 typedef struct journal_revoke_header_s
178 {
179 journal_header_t r_header;
180 int r_count; /* Count of bytes used in the block */
181 } journal_revoke_header_t;
182
183 /* Tail of revoke block, for checksumming */
184 struct journal_revoke_tail {
185 __be32 r_checksum;
186 };
187
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 */
193
194
195 #define UUID_SIZE 16
196 #define JFS_USERS_MAX 48
197 #define JFS_USERS_SIZE (UUID_SIZE * JFS_USERS_MAX)
198 /*
199 * The journal superblock. All fields are in big-endian byte order.
200 */
201 typedef struct journal_superblock_s
202 {
203 /* 0x0000 */
204 journal_header_t s_header;
205
206 /* 0x000C */
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 */
211
212 /* 0x0018 */
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 */
216
217 /* 0x0020 */
218 /* Error value, as set by journal_abort(). */
219 __s32 s_errno;
220
221 /* 0x0024 */
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 */
226 /* 0x0030 */
227 __u8 s_uuid[16]; /* 128-bit uuid for journal */
228
229 /* 0x0040 */
230 __u32 s_nr_users; /* Nr of filesystems sharing log */
231
232 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
233
234 /* 0x0048 */
235 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
236 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
237
238 /* 0x0050 */
239 __u8 s_checksum_type; /* checksum type */
240 __u8 s_padding2[3];
241 __u32 s_padding[42];
242 __u32 s_checksum; /* crc32c(superblock) */
243
244 /* 0x0100 */
245 __u8 s_users[JFS_USERS_SIZE]; /* ids of all fs'es sharing the log */
246
247 /* 0x0400 */
248 } journal_superblock_t;
249
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))))
259
260 #define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001
261
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
267
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)
276
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));
282 #endif
283
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
288 #else
289 #define _INLINE_ inline
290 #endif
291 #else /* !E2FSCK_INCLUDE_INLINE FUNCS */
292 #if (__STDC_VERSION__ >= 199901L)
293 #define _INLINE_ inline
294 #else /* not C99 */
295 #ifdef __GNUC__
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 */
302
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) \
307 { \
308 return ((j)->j_format_version >= 2 && \
309 ((j)->j_superblock->s_feature_compat & \
310 ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname)) != 0); \
311 } \
312 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
313 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
314 { \
315 (j)->j_superblock->s_feature_compat |= \
316 ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname); \
317 } \
318 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
319 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
320 { \
321 (j)->j_superblock->s_feature_compat &= \
322 ~ext2fs_cpu_to_be32(JFS_FEATURE_COMPAT_##flagname); \
323 }
324
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) \
328 { \
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); \
332 } \
333 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
334 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
335 { \
336 (j)->j_superblock->s_feature_ro_compat |= \
337 ext2fs_cpu_to_be32(JFS_FEATURE_RO_COMPAT_##flagname); \
338 } \
339 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
340 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
341 { \
342 (j)->j_superblock->s_feature_ro_compat &= \
343 ~ext2fs_cpu_to_be32(JFS_FEATURE_RO_COMPAT_##flagname); \
344 }
345
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) \
349 { \
350 return ((j)->j_format_version >= 2 && \
351 ((j)->j_superblock->s_feature_incompat & \
352 ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname)) != 0); \
353 } \
354 _INLINE_ void jfs_set_feature_##name(journal_t *j); \
355 _INLINE_ void jfs_set_feature_##name(journal_t *j) \
356 { \
357 (j)->j_superblock->s_feature_incompat |= \
358 ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname); \
359 } \
360 _INLINE_ void jfs_clear_feature_##name(journal_t *j); \
361 _INLINE_ void jfs_clear_feature_##name(journal_t *j) \
362 { \
363 (j)->j_superblock->s_feature_incompat &= \
364 ~ext2fs_cpu_to_be32(JFS_FEATURE_INCOMPAT_##flagname); \
365 }
366
367 #else
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);
372
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);
377
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);
382
383 #endif /* (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS)) */
384
JFS_FEATURE_COMPAT_FUNCS(checksum,CHECKSUM)385 JFS_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
386
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)
392
393 #if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
394 /*
395 * helper functions to deal with 32 or 64bit block numbers.
396 */
397 _INLINE_ size_t journal_tag_bytes(journal_t *journal)
398 {
399 size_t sz;
400
401 if (jfs_has_feature_csum3(journal))
402 return sizeof(journal_block_tag3_t);
403
404 sz = sizeof(journal_block_tag_t);
405
406 if (jfs_has_feature_csum2(journal))
407 sz += sizeof(__u16);
408
409 if (jfs_has_feature_64bit(journal))
410 return sz;
411
412 return sz - sizeof(__u32);
413 }
414
journal_has_csum_v2or3(journal_t * journal)415 _INLINE_ int journal_has_csum_v2or3(journal_t *journal)
416 {
417 if (jfs_has_feature_csum2(journal) || jfs_has_feature_csum3(journal))
418 return 1;
419
420 return 0;
421 }
422
423 /* Comparison functions for transaction IDs: perform comparisons using
424 * modulo arithmetic so that they work over sequence number wraps. */
425
tid_gt(tid_t x,tid_t y)426 _INLINE_ int tid_gt(tid_t x, tid_t y)
427 {
428 int difference = (x - y);
429 return (difference > 0);
430 }
431
tid_geq(tid_t x,tid_t y)432 _INLINE_ int tid_geq(tid_t x, tid_t y)
433 {
434 int difference = (x - y);
435 return (difference >= 0);
436 }
437 #endif /* (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS)) */
438
439 #undef _INLINE_
440
441 extern int journal_blocks_per_page(struct inode *inode);
442
443 /*
444 * Definitions which augment the buffer_head layer
445 */
446
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 */
457 #define BJ_Types 9
458
459 extern int jbd_blocks_per_page(struct inode *inode);
460
461 #endif /* _LINUX_JBD_H */
462