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470decc6 | 1 | /* |
f7f4bccb | 2 | * linux/include/linux/jbd2.h |
470decc6 DK |
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 | ||
cd02ff0b MC |
16 | #ifndef _LINUX_JBD2_H |
17 | #define _LINUX_JBD2_H | |
470decc6 DK |
18 | |
19 | /* Allow this file to be included directly into e2fsprogs */ | |
20 | #ifndef __KERNEL__ | |
21 | #include "jfs_compat.h" | |
f7f4bccb | 22 | #define JBD2_DEBUG |
470decc6 DK |
23 | #define jfs_debug jbd_debug |
24 | #else | |
25 | ||
26 | #include <linux/types.h> | |
27 | #include <linux/buffer_head.h> | |
28 | #include <linux/journal-head.h> | |
29 | #include <linux/stddef.h> | |
30 | #include <linux/bit_spinlock.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/timer.h> | |
33 | ||
34 | #include <asm/semaphore.h> | |
35 | #endif | |
36 | ||
37 | #define journal_oom_retry 1 | |
38 | ||
39 | /* | |
cd02ff0b | 40 | * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds |
470decc6 | 41 | * certain classes of error which can occur due to failed IOs. Under |
cd02ff0b | 42 | * normal use we want ext4 to continue after such errors, because |
470decc6 DK |
43 | * hardware _can_ fail, but for debugging purposes when running tests on |
44 | * known-good hardware we may want to trap these errors. | |
45 | */ | |
cd02ff0b | 46 | #undef JBD2_PARANOID_IOFAIL |
470decc6 DK |
47 | |
48 | /* | |
49 | * The default maximum commit age, in seconds. | |
50 | */ | |
cd02ff0b | 51 | #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 |
470decc6 | 52 | |
e23291b9 | 53 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 | 54 | /* |
cd02ff0b | 55 | * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal |
470decc6 | 56 | * consistency checks. By default we don't do this unless |
e23291b9 | 57 | * CONFIG_JBD2_DEBUG is on. |
470decc6 | 58 | */ |
cd02ff0b | 59 | #define JBD2_EXPENSIVE_CHECKING |
0f49d5d0 | 60 | extern u8 jbd2_journal_enable_debug; |
470decc6 DK |
61 | |
62 | #define jbd_debug(n, f, a...) \ | |
63 | do { \ | |
f7f4bccb | 64 | if ((n) <= jbd2_journal_enable_debug) { \ |
470decc6 DK |
65 | printk (KERN_DEBUG "(%s, %d): %s: ", \ |
66 | __FILE__, __LINE__, __FUNCTION__); \ | |
67 | printk (f, ## a); \ | |
68 | } \ | |
69 | } while (0) | |
70 | #else | |
71 | #define jbd_debug(f, a...) /**/ | |
72 | #endif | |
73 | ||
af1e76d6 MC |
74 | static inline void *jbd2_alloc(size_t size, gfp_t flags) |
75 | { | |
76 | return (void *)__get_free_pages(flags, get_order(size)); | |
77 | } | |
78 | ||
79 | static inline void jbd2_free(void *ptr, size_t size) | |
80 | { | |
81 | free_pages((unsigned long)ptr, get_order(size)); | |
82 | }; | |
83 | ||
f7f4bccb | 84 | #define JBD2_MIN_JOURNAL_BLOCKS 1024 |
470decc6 DK |
85 | |
86 | #ifdef __KERNEL__ | |
87 | ||
88 | /** | |
89 | * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. | |
90 | * | |
91 | * All filesystem modifications made by the process go | |
92 | * through this handle. Recursive operations (such as quota operations) | |
93 | * are gathered into a single update. | |
94 | * | |
95 | * The buffer credits field is used to account for journaled buffers | |
96 | * being modified by the running process. To ensure that there is | |
97 | * enough log space for all outstanding operations, we need to limit the | |
98 | * number of outstanding buffers possible at any time. When the | |
99 | * operation completes, any buffer credits not used are credited back to | |
100 | * the transaction, so that at all times we know how many buffers the | |
101 | * outstanding updates on a transaction might possibly touch. | |
102 | * | |
103 | * This is an opaque datatype. | |
104 | **/ | |
105 | typedef struct handle_s handle_t; /* Atomic operation type */ | |
106 | ||
107 | ||
108 | /** | |
109 | * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. | |
110 | * | |
111 | * journal_t is linked to from the fs superblock structure. | |
112 | * | |
113 | * We use the journal_t to keep track of all outstanding transaction | |
114 | * activity on the filesystem, and to manage the state of the log | |
115 | * writing process. | |
116 | * | |
117 | * This is an opaque datatype. | |
118 | **/ | |
119 | typedef struct journal_s journal_t; /* Journal control structure */ | |
120 | #endif | |
121 | ||
122 | /* | |
123 | * Internal structures used by the logging mechanism: | |
124 | */ | |
125 | ||
f7f4bccb | 126 | #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ |
470decc6 DK |
127 | |
128 | /* | |
129 | * On-disk structures | |
130 | */ | |
131 | ||
132 | /* | |
133 | * Descriptor block types: | |
134 | */ | |
135 | ||
f7f4bccb MC |
136 | #define JBD2_DESCRIPTOR_BLOCK 1 |
137 | #define JBD2_COMMIT_BLOCK 2 | |
138 | #define JBD2_SUPERBLOCK_V1 3 | |
139 | #define JBD2_SUPERBLOCK_V2 4 | |
140 | #define JBD2_REVOKE_BLOCK 5 | |
470decc6 DK |
141 | |
142 | /* | |
143 | * Standard header for all descriptor blocks: | |
144 | */ | |
145 | typedef struct journal_header_s | |
146 | { | |
147 | __be32 h_magic; | |
148 | __be32 h_blocktype; | |
149 | __be32 h_sequence; | |
150 | } journal_header_t; | |
151 | ||
152 | ||
153 | /* | |
b517bea1 ZB |
154 | * The block tag: used to describe a single buffer in the journal. |
155 | * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this | |
156 | * raw struct shouldn't be used for pointer math or sizeof() - use | |
157 | * journal_tag_bytes(journal) instead to compute this. | |
470decc6 DK |
158 | */ |
159 | typedef struct journal_block_tag_s | |
160 | { | |
161 | __be32 t_blocknr; /* The on-disk block number */ | |
162 | __be32 t_flags; /* See below */ | |
b517bea1 | 163 | __be32 t_blocknr_high; /* most-significant high 32bits. */ |
470decc6 DK |
164 | } journal_block_tag_t; |
165 | ||
cd02ff0b MC |
166 | #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) |
167 | #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) | |
b517bea1 | 168 | |
470decc6 DK |
169 | /* |
170 | * The revoke descriptor: used on disk to describe a series of blocks to | |
171 | * be revoked from the log | |
172 | */ | |
f7f4bccb | 173 | typedef struct jbd2_journal_revoke_header_s |
470decc6 DK |
174 | { |
175 | journal_header_t r_header; | |
176 | __be32 r_count; /* Count of bytes used in the block */ | |
f7f4bccb | 177 | } jbd2_journal_revoke_header_t; |
470decc6 DK |
178 | |
179 | ||
180 | /* Definitions for the journal tag flags word: */ | |
f7f4bccb MC |
181 | #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ |
182 | #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ | |
183 | #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ | |
184 | #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ | |
470decc6 DK |
185 | |
186 | ||
187 | /* | |
188 | * The journal superblock. All fields are in big-endian byte order. | |
189 | */ | |
190 | typedef struct journal_superblock_s | |
191 | { | |
192 | /* 0x0000 */ | |
193 | journal_header_t s_header; | |
194 | ||
195 | /* 0x000C */ | |
196 | /* Static information describing the journal */ | |
197 | __be32 s_blocksize; /* journal device blocksize */ | |
198 | __be32 s_maxlen; /* total blocks in journal file */ | |
199 | __be32 s_first; /* first block of log information */ | |
200 | ||
201 | /* 0x0018 */ | |
202 | /* Dynamic information describing the current state of the log */ | |
203 | __be32 s_sequence; /* first commit ID expected in log */ | |
204 | __be32 s_start; /* blocknr of start of log */ | |
205 | ||
206 | /* 0x0020 */ | |
f7f4bccb | 207 | /* Error value, as set by jbd2_journal_abort(). */ |
470decc6 DK |
208 | __be32 s_errno; |
209 | ||
210 | /* 0x0024 */ | |
211 | /* Remaining fields are only valid in a version-2 superblock */ | |
212 | __be32 s_feature_compat; /* compatible feature set */ | |
213 | __be32 s_feature_incompat; /* incompatible feature set */ | |
214 | __be32 s_feature_ro_compat; /* readonly-compatible feature set */ | |
215 | /* 0x0030 */ | |
216 | __u8 s_uuid[16]; /* 128-bit uuid for journal */ | |
217 | ||
218 | /* 0x0040 */ | |
219 | __be32 s_nr_users; /* Nr of filesystems sharing log */ | |
220 | ||
221 | __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ | |
222 | ||
223 | /* 0x0048 */ | |
224 | __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ | |
225 | __be32 s_max_trans_data; /* Limit of data blocks per trans. */ | |
226 | ||
227 | /* 0x0050 */ | |
228 | __u32 s_padding[44]; | |
229 | ||
230 | /* 0x0100 */ | |
231 | __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ | |
232 | /* 0x0400 */ | |
233 | } journal_superblock_t; | |
234 | ||
f7f4bccb | 235 | #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ |
470decc6 DK |
236 | ((j)->j_format_version >= 2 && \ |
237 | ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) | |
f7f4bccb | 238 | #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ |
470decc6 DK |
239 | ((j)->j_format_version >= 2 && \ |
240 | ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) | |
f7f4bccb | 241 | #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ |
470decc6 DK |
242 | ((j)->j_format_version >= 2 && \ |
243 | ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) | |
244 | ||
f7f4bccb | 245 | #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 |
b517bea1 | 246 | #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 |
470decc6 DK |
247 | |
248 | /* Features known to this kernel version: */ | |
f7f4bccb MC |
249 | #define JBD2_KNOWN_COMPAT_FEATURES 0 |
250 | #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 | |
b517bea1 ZB |
251 | #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ |
252 | JBD2_FEATURE_INCOMPAT_64BIT) | |
470decc6 DK |
253 | |
254 | #ifdef __KERNEL__ | |
255 | ||
256 | #include <linux/fs.h> | |
257 | #include <linux/sched.h> | |
258 | ||
36df53f4 | 259 | #define J_ASSERT(assert) BUG_ON(!(assert)) |
470decc6 DK |
260 | |
261 | #if defined(CONFIG_BUFFER_DEBUG) | |
262 | void buffer_assertion_failure(struct buffer_head *bh); | |
263 | #define J_ASSERT_BH(bh, expr) \ | |
264 | do { \ | |
265 | if (!(expr)) \ | |
266 | buffer_assertion_failure(bh); \ | |
267 | J_ASSERT(expr); \ | |
268 | } while (0) | |
269 | #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) | |
270 | #else | |
271 | #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) | |
272 | #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) | |
273 | #endif | |
274 | ||
cd02ff0b | 275 | #if defined(JBD2_PARANOID_IOFAIL) |
470decc6 DK |
276 | #define J_EXPECT(expr, why...) J_ASSERT(expr) |
277 | #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) | |
278 | #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) | |
279 | #else | |
280 | #define __journal_expect(expr, why...) \ | |
281 | ({ \ | |
282 | int val = (expr); \ | |
283 | if (!val) { \ | |
284 | printk(KERN_ERR \ | |
285 | "EXT3-fs unexpected failure: %s;\n",# expr); \ | |
286 | printk(KERN_ERR why "\n"); \ | |
287 | } \ | |
288 | val; \ | |
289 | }) | |
290 | #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) | |
291 | #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) | |
292 | #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) | |
293 | #endif | |
294 | ||
295 | enum jbd_state_bits { | |
296 | BH_JBD /* Has an attached ext3 journal_head */ | |
297 | = BH_PrivateStart, | |
298 | BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ | |
299 | BH_Freed, /* Has been freed (truncated) */ | |
300 | BH_Revoked, /* Has been revoked from the log */ | |
301 | BH_RevokeValid, /* Revoked flag is valid */ | |
302 | BH_JBDDirty, /* Is dirty but journaled */ | |
303 | BH_State, /* Pins most journal_head state */ | |
304 | BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ | |
305 | BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ | |
306 | }; | |
307 | ||
308 | BUFFER_FNS(JBD, jbd) | |
309 | BUFFER_FNS(JWrite, jwrite) | |
310 | BUFFER_FNS(JBDDirty, jbddirty) | |
311 | TAS_BUFFER_FNS(JBDDirty, jbddirty) | |
312 | BUFFER_FNS(Revoked, revoked) | |
313 | TAS_BUFFER_FNS(Revoked, revoked) | |
314 | BUFFER_FNS(RevokeValid, revokevalid) | |
315 | TAS_BUFFER_FNS(RevokeValid, revokevalid) | |
316 | BUFFER_FNS(Freed, freed) | |
317 | ||
318 | static inline struct buffer_head *jh2bh(struct journal_head *jh) | |
319 | { | |
320 | return jh->b_bh; | |
321 | } | |
322 | ||
323 | static inline struct journal_head *bh2jh(struct buffer_head *bh) | |
324 | { | |
325 | return bh->b_private; | |
326 | } | |
327 | ||
328 | static inline void jbd_lock_bh_state(struct buffer_head *bh) | |
329 | { | |
330 | bit_spin_lock(BH_State, &bh->b_state); | |
331 | } | |
332 | ||
333 | static inline int jbd_trylock_bh_state(struct buffer_head *bh) | |
334 | { | |
335 | return bit_spin_trylock(BH_State, &bh->b_state); | |
336 | } | |
337 | ||
338 | static inline int jbd_is_locked_bh_state(struct buffer_head *bh) | |
339 | { | |
340 | return bit_spin_is_locked(BH_State, &bh->b_state); | |
341 | } | |
342 | ||
343 | static inline void jbd_unlock_bh_state(struct buffer_head *bh) | |
344 | { | |
345 | bit_spin_unlock(BH_State, &bh->b_state); | |
346 | } | |
347 | ||
348 | static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) | |
349 | { | |
350 | bit_spin_lock(BH_JournalHead, &bh->b_state); | |
351 | } | |
352 | ||
353 | static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) | |
354 | { | |
355 | bit_spin_unlock(BH_JournalHead, &bh->b_state); | |
356 | } | |
357 | ||
f7f4bccb | 358 | struct jbd2_revoke_table_s; |
470decc6 DK |
359 | |
360 | /** | |
361 | * struct handle_s - The handle_s type is the concrete type associated with | |
362 | * handle_t. | |
363 | * @h_transaction: Which compound transaction is this update a part of? | |
364 | * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. | |
365 | * @h_ref: Reference count on this handle | |
366 | * @h_err: Field for caller's use to track errors through large fs operations | |
367 | * @h_sync: flag for sync-on-close | |
368 | * @h_jdata: flag to force data journaling | |
369 | * @h_aborted: flag indicating fatal error on handle | |
370 | **/ | |
371 | ||
372 | /* Docbook can't yet cope with the bit fields, but will leave the documentation | |
373 | * in so it can be fixed later. | |
374 | */ | |
375 | ||
376 | struct handle_s | |
377 | { | |
378 | /* Which compound transaction is this update a part of? */ | |
379 | transaction_t *h_transaction; | |
380 | ||
381 | /* Number of remaining buffers we are allowed to dirty: */ | |
382 | int h_buffer_credits; | |
383 | ||
384 | /* Reference count on this handle */ | |
385 | int h_ref; | |
386 | ||
387 | /* Field for caller's use to track errors through large fs */ | |
388 | /* operations */ | |
389 | int h_err; | |
390 | ||
391 | /* Flags [no locking] */ | |
392 | unsigned int h_sync: 1; /* sync-on-close */ | |
393 | unsigned int h_jdata: 1; /* force data journaling */ | |
394 | unsigned int h_aborted: 1; /* fatal error on handle */ | |
395 | }; | |
396 | ||
397 | ||
398 | /* The transaction_t type is the guts of the journaling mechanism. It | |
399 | * tracks a compound transaction through its various states: | |
400 | * | |
401 | * RUNNING: accepting new updates | |
402 | * LOCKED: Updates still running but we don't accept new ones | |
403 | * RUNDOWN: Updates are tidying up but have finished requesting | |
404 | * new buffers to modify (state not used for now) | |
405 | * FLUSH: All updates complete, but we are still writing to disk | |
406 | * COMMIT: All data on disk, writing commit record | |
407 | * FINISHED: We still have to keep the transaction for checkpointing. | |
408 | * | |
409 | * The transaction keeps track of all of the buffers modified by a | |
410 | * running transaction, and all of the buffers committed but not yet | |
411 | * flushed to home for finished transactions. | |
412 | */ | |
413 | ||
414 | /* | |
415 | * Lock ranking: | |
416 | * | |
417 | * j_list_lock | |
418 | * ->jbd_lock_bh_journal_head() (This is "innermost") | |
419 | * | |
420 | * j_state_lock | |
421 | * ->jbd_lock_bh_state() | |
422 | * | |
423 | * jbd_lock_bh_state() | |
424 | * ->j_list_lock | |
425 | * | |
426 | * j_state_lock | |
427 | * ->t_handle_lock | |
428 | * | |
429 | * j_state_lock | |
430 | * ->j_list_lock (journal_unmap_buffer) | |
431 | * | |
432 | */ | |
433 | ||
434 | struct transaction_s | |
435 | { | |
436 | /* Pointer to the journal for this transaction. [no locking] */ | |
437 | journal_t *t_journal; | |
438 | ||
439 | /* Sequence number for this transaction [no locking] */ | |
440 | tid_t t_tid; | |
441 | ||
442 | /* | |
443 | * Transaction's current state | |
f7f4bccb | 444 | * [no locking - only kjournald2 alters this] |
f5a7a6b0 JK |
445 | * [j_list_lock] guards transition of a transaction into T_FINISHED |
446 | * state and subsequent call of __jbd2_journal_drop_transaction() | |
470decc6 DK |
447 | * FIXME: needs barriers |
448 | * KLUDGE: [use j_state_lock] | |
449 | */ | |
450 | enum { | |
451 | T_RUNNING, | |
452 | T_LOCKED, | |
453 | T_RUNDOWN, | |
454 | T_FLUSH, | |
455 | T_COMMIT, | |
456 | T_FINISHED | |
457 | } t_state; | |
458 | ||
459 | /* | |
460 | * Where in the log does this transaction's commit start? [no locking] | |
461 | */ | |
462 | unsigned long t_log_start; | |
463 | ||
464 | /* Number of buffers on the t_buffers list [j_list_lock] */ | |
465 | int t_nr_buffers; | |
466 | ||
467 | /* | |
468 | * Doubly-linked circular list of all buffers reserved but not yet | |
469 | * modified by this transaction [j_list_lock] | |
470 | */ | |
471 | struct journal_head *t_reserved_list; | |
472 | ||
473 | /* | |
474 | * Doubly-linked circular list of all buffers under writeout during | |
475 | * commit [j_list_lock] | |
476 | */ | |
477 | struct journal_head *t_locked_list; | |
478 | ||
479 | /* | |
480 | * Doubly-linked circular list of all metadata buffers owned by this | |
481 | * transaction [j_list_lock] | |
482 | */ | |
483 | struct journal_head *t_buffers; | |
484 | ||
485 | /* | |
486 | * Doubly-linked circular list of all data buffers still to be | |
487 | * flushed before this transaction can be committed [j_list_lock] | |
488 | */ | |
489 | struct journal_head *t_sync_datalist; | |
490 | ||
491 | /* | |
492 | * Doubly-linked circular list of all forget buffers (superseded | |
493 | * buffers which we can un-checkpoint once this transaction commits) | |
494 | * [j_list_lock] | |
495 | */ | |
496 | struct journal_head *t_forget; | |
497 | ||
498 | /* | |
499 | * Doubly-linked circular list of all buffers still to be flushed before | |
500 | * this transaction can be checkpointed. [j_list_lock] | |
501 | */ | |
502 | struct journal_head *t_checkpoint_list; | |
503 | ||
504 | /* | |
505 | * Doubly-linked circular list of all buffers submitted for IO while | |
506 | * checkpointing. [j_list_lock] | |
507 | */ | |
508 | struct journal_head *t_checkpoint_io_list; | |
509 | ||
510 | /* | |
511 | * Doubly-linked circular list of temporary buffers currently undergoing | |
512 | * IO in the log [j_list_lock] | |
513 | */ | |
514 | struct journal_head *t_iobuf_list; | |
515 | ||
516 | /* | |
517 | * Doubly-linked circular list of metadata buffers being shadowed by log | |
518 | * IO. The IO buffers on the iobuf list and the shadow buffers on this | |
519 | * list match each other one for one at all times. [j_list_lock] | |
520 | */ | |
521 | struct journal_head *t_shadow_list; | |
522 | ||
523 | /* | |
524 | * Doubly-linked circular list of control buffers being written to the | |
525 | * log. [j_list_lock] | |
526 | */ | |
527 | struct journal_head *t_log_list; | |
528 | ||
529 | /* | |
530 | * Protects info related to handles | |
531 | */ | |
532 | spinlock_t t_handle_lock; | |
533 | ||
534 | /* | |
535 | * Number of outstanding updates running on this transaction | |
536 | * [t_handle_lock] | |
537 | */ | |
538 | int t_updates; | |
539 | ||
540 | /* | |
541 | * Number of buffers reserved for use by all handles in this transaction | |
542 | * handle but not yet modified. [t_handle_lock] | |
543 | */ | |
544 | int t_outstanding_credits; | |
545 | ||
546 | /* | |
547 | * Forward and backward links for the circular list of all transactions | |
548 | * awaiting checkpoint. [j_list_lock] | |
549 | */ | |
550 | transaction_t *t_cpnext, *t_cpprev; | |
551 | ||
552 | /* | |
553 | * When will the transaction expire (become due for commit), in jiffies? | |
554 | * [no locking] | |
555 | */ | |
556 | unsigned long t_expires; | |
557 | ||
558 | /* | |
559 | * How many handles used this transaction? [t_handle_lock] | |
560 | */ | |
561 | int t_handle_count; | |
562 | ||
563 | }; | |
564 | ||
565 | /** | |
566 | * struct journal_s - The journal_s type is the concrete type associated with | |
567 | * journal_t. | |
568 | * @j_flags: General journaling state flags | |
569 | * @j_errno: Is there an outstanding uncleared error on the journal (from a | |
570 | * prior abort)? | |
571 | * @j_sb_buffer: First part of superblock buffer | |
572 | * @j_superblock: Second part of superblock buffer | |
573 | * @j_format_version: Version of the superblock format | |
574 | * @j_state_lock: Protect the various scalars in the journal | |
575 | * @j_barrier_count: Number of processes waiting to create a barrier lock | |
576 | * @j_barrier: The barrier lock itself | |
577 | * @j_running_transaction: The current running transaction.. | |
578 | * @j_committing_transaction: the transaction we are pushing to disk | |
579 | * @j_checkpoint_transactions: a linked circular list of all transactions | |
580 | * waiting for checkpointing | |
581 | * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction | |
582 | * to start committing, or for a barrier lock to be released | |
583 | * @j_wait_logspace: Wait queue for waiting for checkpointing to complete | |
584 | * @j_wait_done_commit: Wait queue for waiting for commit to complete | |
585 | * @j_wait_checkpoint: Wait queue to trigger checkpointing | |
586 | * @j_wait_commit: Wait queue to trigger commit | |
587 | * @j_wait_updates: Wait queue to wait for updates to complete | |
588 | * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints | |
589 | * @j_head: Journal head - identifies the first unused block in the journal | |
590 | * @j_tail: Journal tail - identifies the oldest still-used block in the | |
591 | * journal. | |
592 | * @j_free: Journal free - how many free blocks are there in the journal? | |
593 | * @j_first: The block number of the first usable block | |
594 | * @j_last: The block number one beyond the last usable block | |
595 | * @j_dev: Device where we store the journal | |
596 | * @j_blocksize: blocksize for the location where we store the journal. | |
597 | * @j_blk_offset: starting block offset for into the device where we store the | |
598 | * journal | |
599 | * @j_fs_dev: Device which holds the client fs. For internal journal this will | |
600 | * be equal to j_dev | |
601 | * @j_maxlen: Total maximum capacity of the journal region on disk. | |
602 | * @j_list_lock: Protects the buffer lists and internal buffer state. | |
603 | * @j_inode: Optional inode where we store the journal. If present, all journal | |
604 | * block numbers are mapped into this inode via bmap(). | |
605 | * @j_tail_sequence: Sequence number of the oldest transaction in the log | |
606 | * @j_transaction_sequence: Sequence number of the next transaction to grant | |
607 | * @j_commit_sequence: Sequence number of the most recently committed | |
608 | * transaction | |
609 | * @j_commit_request: Sequence number of the most recent transaction wanting | |
610 | * commit | |
611 | * @j_uuid: Uuid of client object. | |
612 | * @j_task: Pointer to the current commit thread for this journal | |
613 | * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a | |
614 | * single compound commit transaction | |
615 | * @j_commit_interval: What is the maximum transaction lifetime before we begin | |
616 | * a commit? | |
617 | * @j_commit_timer: The timer used to wakeup the commit thread | |
618 | * @j_revoke_lock: Protect the revoke table | |
619 | * @j_revoke: The revoke table - maintains the list of revoked blocks in the | |
620 | * current transaction. | |
621 | * @j_revoke_table: alternate revoke tables for j_revoke | |
f7f4bccb | 622 | * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction |
470decc6 DK |
623 | * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the |
624 | * number that will fit in j_blocksize | |
625 | * @j_last_sync_writer: most recent pid which did a synchronous write | |
626 | * @j_private: An opaque pointer to fs-private information. | |
627 | */ | |
628 | ||
629 | struct journal_s | |
630 | { | |
631 | /* General journaling state flags [j_state_lock] */ | |
632 | unsigned long j_flags; | |
633 | ||
634 | /* | |
635 | * Is there an outstanding uncleared error on the journal (from a prior | |
636 | * abort)? [j_state_lock] | |
637 | */ | |
638 | int j_errno; | |
639 | ||
640 | /* The superblock buffer */ | |
641 | struct buffer_head *j_sb_buffer; | |
642 | journal_superblock_t *j_superblock; | |
643 | ||
644 | /* Version of the superblock format */ | |
645 | int j_format_version; | |
646 | ||
647 | /* | |
648 | * Protect the various scalars in the journal | |
649 | */ | |
650 | spinlock_t j_state_lock; | |
651 | ||
652 | /* | |
653 | * Number of processes waiting to create a barrier lock [j_state_lock] | |
654 | */ | |
655 | int j_barrier_count; | |
656 | ||
657 | /* The barrier lock itself */ | |
658 | struct mutex j_barrier; | |
659 | ||
660 | /* | |
661 | * Transactions: The current running transaction... | |
662 | * [j_state_lock] [caller holding open handle] | |
663 | */ | |
664 | transaction_t *j_running_transaction; | |
665 | ||
666 | /* | |
667 | * the transaction we are pushing to disk | |
668 | * [j_state_lock] [caller holding open handle] | |
669 | */ | |
670 | transaction_t *j_committing_transaction; | |
671 | ||
672 | /* | |
673 | * ... and a linked circular list of all transactions waiting for | |
674 | * checkpointing. [j_list_lock] | |
675 | */ | |
676 | transaction_t *j_checkpoint_transactions; | |
677 | ||
678 | /* | |
679 | * Wait queue for waiting for a locked transaction to start committing, | |
680 | * or for a barrier lock to be released | |
681 | */ | |
682 | wait_queue_head_t j_wait_transaction_locked; | |
683 | ||
684 | /* Wait queue for waiting for checkpointing to complete */ | |
685 | wait_queue_head_t j_wait_logspace; | |
686 | ||
687 | /* Wait queue for waiting for commit to complete */ | |
688 | wait_queue_head_t j_wait_done_commit; | |
689 | ||
690 | /* Wait queue to trigger checkpointing */ | |
691 | wait_queue_head_t j_wait_checkpoint; | |
692 | ||
693 | /* Wait queue to trigger commit */ | |
694 | wait_queue_head_t j_wait_commit; | |
695 | ||
696 | /* Wait queue to wait for updates to complete */ | |
697 | wait_queue_head_t j_wait_updates; | |
698 | ||
699 | /* Semaphore for locking against concurrent checkpoints */ | |
700 | struct mutex j_checkpoint_mutex; | |
701 | ||
702 | /* | |
703 | * Journal head: identifies the first unused block in the journal. | |
704 | * [j_state_lock] | |
705 | */ | |
706 | unsigned long j_head; | |
707 | ||
708 | /* | |
709 | * Journal tail: identifies the oldest still-used block in the journal. | |
710 | * [j_state_lock] | |
711 | */ | |
712 | unsigned long j_tail; | |
713 | ||
714 | /* | |
715 | * Journal free: how many free blocks are there in the journal? | |
716 | * [j_state_lock] | |
717 | */ | |
718 | unsigned long j_free; | |
719 | ||
720 | /* | |
721 | * Journal start and end: the block numbers of the first usable block | |
722 | * and one beyond the last usable block in the journal. [j_state_lock] | |
723 | */ | |
724 | unsigned long j_first; | |
725 | unsigned long j_last; | |
726 | ||
727 | /* | |
728 | * Device, blocksize and starting block offset for the location where we | |
729 | * store the journal. | |
730 | */ | |
731 | struct block_device *j_dev; | |
732 | int j_blocksize; | |
18eba7aa | 733 | unsigned long long j_blk_offset; |
470decc6 DK |
734 | |
735 | /* | |
736 | * Device which holds the client fs. For internal journal this will be | |
737 | * equal to j_dev. | |
738 | */ | |
739 | struct block_device *j_fs_dev; | |
740 | ||
741 | /* Total maximum capacity of the journal region on disk. */ | |
742 | unsigned int j_maxlen; | |
743 | ||
744 | /* | |
745 | * Protects the buffer lists and internal buffer state. | |
746 | */ | |
747 | spinlock_t j_list_lock; | |
748 | ||
749 | /* Optional inode where we store the journal. If present, all */ | |
750 | /* journal block numbers are mapped into this inode via */ | |
751 | /* bmap(). */ | |
752 | struct inode *j_inode; | |
753 | ||
754 | /* | |
755 | * Sequence number of the oldest transaction in the log [j_state_lock] | |
756 | */ | |
757 | tid_t j_tail_sequence; | |
758 | ||
759 | /* | |
760 | * Sequence number of the next transaction to grant [j_state_lock] | |
761 | */ | |
762 | tid_t j_transaction_sequence; | |
763 | ||
764 | /* | |
765 | * Sequence number of the most recently committed transaction | |
766 | * [j_state_lock]. | |
767 | */ | |
768 | tid_t j_commit_sequence; | |
769 | ||
770 | /* | |
771 | * Sequence number of the most recent transaction wanting commit | |
772 | * [j_state_lock] | |
773 | */ | |
774 | tid_t j_commit_request; | |
775 | ||
776 | /* | |
777 | * Journal uuid: identifies the object (filesystem, LVM volume etc) | |
778 | * backed by this journal. This will eventually be replaced by an array | |
779 | * of uuids, allowing us to index multiple devices within a single | |
780 | * journal and to perform atomic updates across them. | |
781 | */ | |
782 | __u8 j_uuid[16]; | |
783 | ||
784 | /* Pointer to the current commit thread for this journal */ | |
785 | struct task_struct *j_task; | |
786 | ||
787 | /* | |
788 | * Maximum number of metadata buffers to allow in a single compound | |
789 | * commit transaction | |
790 | */ | |
791 | int j_max_transaction_buffers; | |
792 | ||
793 | /* | |
794 | * What is the maximum transaction lifetime before we begin a commit? | |
795 | */ | |
796 | unsigned long j_commit_interval; | |
797 | ||
798 | /* The timer used to wakeup the commit thread: */ | |
799 | struct timer_list j_commit_timer; | |
800 | ||
801 | /* | |
802 | * The revoke table: maintains the list of revoked blocks in the | |
803 | * current transaction. [j_revoke_lock] | |
804 | */ | |
805 | spinlock_t j_revoke_lock; | |
f7f4bccb MC |
806 | struct jbd2_revoke_table_s *j_revoke; |
807 | struct jbd2_revoke_table_s *j_revoke_table[2]; | |
470decc6 DK |
808 | |
809 | /* | |
f7f4bccb | 810 | * array of bhs for jbd2_journal_commit_transaction |
470decc6 DK |
811 | */ |
812 | struct buffer_head **j_wbuf; | |
813 | int j_wbufsize; | |
814 | ||
815 | pid_t j_last_sync_writer; | |
816 | ||
817 | /* | |
818 | * An opaque pointer to fs-private information. ext3 puts its | |
819 | * superblock pointer here | |
820 | */ | |
821 | void *j_private; | |
822 | }; | |
823 | ||
824 | /* | |
825 | * Journal flag definitions | |
826 | */ | |
f7f4bccb MC |
827 | #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ |
828 | #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ | |
829 | #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ | |
830 | #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ | |
831 | #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ | |
832 | #define JBD2_BARRIER 0x020 /* Use IDE barriers */ | |
470decc6 DK |
833 | |
834 | /* | |
835 | * Function declarations for the journaling transaction and buffer | |
836 | * management | |
837 | */ | |
838 | ||
839 | /* Filing buffers */ | |
f7f4bccb MC |
840 | extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); |
841 | extern void __jbd2_journal_unfile_buffer(struct journal_head *); | |
842 | extern void __jbd2_journal_refile_buffer(struct journal_head *); | |
843 | extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); | |
844 | extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); | |
470decc6 | 845 | extern void __journal_free_buffer(struct journal_head *bh); |
f7f4bccb | 846 | extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); |
470decc6 DK |
847 | extern void __journal_clean_data_list(transaction_t *transaction); |
848 | ||
849 | /* Log buffer allocation */ | |
f7f4bccb | 850 | extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); |
18eba7aa | 851 | int jbd2_journal_next_log_block(journal_t *, unsigned long long *); |
470decc6 DK |
852 | |
853 | /* Commit management */ | |
f7f4bccb | 854 | extern void jbd2_journal_commit_transaction(journal_t *); |
470decc6 DK |
855 | |
856 | /* Checkpoint list management */ | |
f7f4bccb MC |
857 | int __jbd2_journal_clean_checkpoint_list(journal_t *journal); |
858 | int __jbd2_journal_remove_checkpoint(struct journal_head *); | |
859 | void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); | |
470decc6 DK |
860 | |
861 | /* Buffer IO */ | |
862 | extern int | |
f7f4bccb | 863 | jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
470decc6 DK |
864 | struct journal_head *jh_in, |
865 | struct journal_head **jh_out, | |
18eba7aa | 866 | unsigned long long blocknr); |
470decc6 DK |
867 | |
868 | /* Transaction locking */ | |
869 | extern void __wait_on_journal (journal_t *); | |
870 | ||
871 | /* | |
872 | * Journal locking. | |
873 | * | |
874 | * We need to lock the journal during transaction state changes so that nobody | |
875 | * ever tries to take a handle on the running transaction while we are in the | |
876 | * middle of moving it to the commit phase. j_state_lock does this. | |
877 | * | |
878 | * Note that the locking is completely interrupt unsafe. We never touch | |
879 | * journal structures from interrupts. | |
880 | */ | |
881 | ||
882 | static inline handle_t *journal_current_handle(void) | |
883 | { | |
884 | return current->journal_info; | |
885 | } | |
886 | ||
887 | /* The journaling code user interface: | |
888 | * | |
889 | * Create and destroy handles | |
890 | * Register buffer modifications against the current transaction. | |
891 | */ | |
892 | ||
f7f4bccb MC |
893 | extern handle_t *jbd2_journal_start(journal_t *, int nblocks); |
894 | extern int jbd2_journal_restart (handle_t *, int nblocks); | |
895 | extern int jbd2_journal_extend (handle_t *, int nblocks); | |
896 | extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); | |
897 | extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); | |
898 | extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); | |
899 | extern int jbd2_journal_dirty_data (handle_t *, struct buffer_head *); | |
900 | extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); | |
901 | extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); | |
902 | extern int jbd2_journal_forget (handle_t *, struct buffer_head *); | |
470decc6 | 903 | extern void journal_sync_buffer (struct buffer_head *); |
f7f4bccb | 904 | extern void jbd2_journal_invalidatepage(journal_t *, |
470decc6 | 905 | struct page *, unsigned long); |
f7f4bccb MC |
906 | extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); |
907 | extern int jbd2_journal_stop(handle_t *); | |
908 | extern int jbd2_journal_flush (journal_t *); | |
909 | extern void jbd2_journal_lock_updates (journal_t *); | |
910 | extern void jbd2_journal_unlock_updates (journal_t *); | |
470decc6 | 911 | |
f7f4bccb | 912 | extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
470decc6 | 913 | struct block_device *fs_dev, |
18eba7aa | 914 | unsigned long long start, int len, int bsize); |
f7f4bccb MC |
915 | extern journal_t * jbd2_journal_init_inode (struct inode *); |
916 | extern int jbd2_journal_update_format (journal_t *); | |
917 | extern int jbd2_journal_check_used_features | |
470decc6 | 918 | (journal_t *, unsigned long, unsigned long, unsigned long); |
f7f4bccb | 919 | extern int jbd2_journal_check_available_features |
470decc6 | 920 | (journal_t *, unsigned long, unsigned long, unsigned long); |
f7f4bccb | 921 | extern int jbd2_journal_set_features |
470decc6 | 922 | (journal_t *, unsigned long, unsigned long, unsigned long); |
f7f4bccb MC |
923 | extern int jbd2_journal_create (journal_t *); |
924 | extern int jbd2_journal_load (journal_t *journal); | |
925 | extern void jbd2_journal_destroy (journal_t *); | |
926 | extern int jbd2_journal_recover (journal_t *journal); | |
927 | extern int jbd2_journal_wipe (journal_t *, int); | |
928 | extern int jbd2_journal_skip_recovery (journal_t *); | |
929 | extern void jbd2_journal_update_superblock (journal_t *, int); | |
930 | extern void __jbd2_journal_abort_hard (journal_t *); | |
931 | extern void jbd2_journal_abort (journal_t *, int); | |
932 | extern int jbd2_journal_errno (journal_t *); | |
933 | extern void jbd2_journal_ack_err (journal_t *); | |
934 | extern int jbd2_journal_clear_err (journal_t *); | |
18eba7aa | 935 | extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); |
f7f4bccb | 936 | extern int jbd2_journal_force_commit(journal_t *); |
470decc6 DK |
937 | |
938 | /* | |
939 | * journal_head management | |
940 | */ | |
f7f4bccb MC |
941 | struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); |
942 | struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); | |
943 | void jbd2_journal_remove_journal_head(struct buffer_head *bh); | |
944 | void jbd2_journal_put_journal_head(struct journal_head *jh); | |
470decc6 DK |
945 | |
946 | /* | |
947 | * handle management | |
948 | */ | |
e18b890b | 949 | extern struct kmem_cache *jbd2_handle_cache; |
470decc6 | 950 | |
af1e76d6 | 951 | static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) |
470decc6 | 952 | { |
f7f4bccb | 953 | return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); |
470decc6 DK |
954 | } |
955 | ||
af1e76d6 | 956 | static inline void jbd2_free_handle(handle_t *handle) |
470decc6 | 957 | { |
f7f4bccb | 958 | kmem_cache_free(jbd2_handle_cache, handle); |
470decc6 DK |
959 | } |
960 | ||
961 | /* Primary revoke support */ | |
962 | #define JOURNAL_REVOKE_DEFAULT_HASH 256 | |
f7f4bccb MC |
963 | extern int jbd2_journal_init_revoke(journal_t *, int); |
964 | extern void jbd2_journal_destroy_revoke_caches(void); | |
965 | extern int jbd2_journal_init_revoke_caches(void); | |
470decc6 | 966 | |
f7f4bccb | 967 | extern void jbd2_journal_destroy_revoke(journal_t *); |
18eba7aa | 968 | extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); |
f7f4bccb MC |
969 | extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); |
970 | extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *); | |
470decc6 DK |
971 | |
972 | /* Recovery revoke support */ | |
18eba7aa MC |
973 | extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); |
974 | extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); | |
f7f4bccb MC |
975 | extern void jbd2_journal_clear_revoke(journal_t *); |
976 | extern void jbd2_journal_switch_revoke_table(journal_t *journal); | |
470decc6 DK |
977 | |
978 | /* | |
979 | * The log thread user interface: | |
980 | * | |
981 | * Request space in the current transaction, and force transaction commit | |
982 | * transitions on demand. | |
983 | */ | |
984 | ||
f7f4bccb MC |
985 | int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ |
986 | int jbd2_log_start_commit(journal_t *journal, tid_t tid); | |
987 | int __jbd2_log_start_commit(journal_t *journal, tid_t tid); | |
988 | int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); | |
989 | int jbd2_journal_force_commit_nested(journal_t *journal); | |
990 | int jbd2_log_wait_commit(journal_t *journal, tid_t tid); | |
991 | int jbd2_log_do_checkpoint(journal_t *journal); | |
470decc6 | 992 | |
f7f4bccb MC |
993 | void __jbd2_log_wait_for_space(journal_t *journal); |
994 | extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); | |
995 | extern int jbd2_cleanup_journal_tail(journal_t *); | |
470decc6 DK |
996 | |
997 | /* Debugging code only: */ | |
998 | ||
999 | #define jbd_ENOSYS() \ | |
1000 | do { \ | |
1001 | printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \ | |
1002 | current->state = TASK_UNINTERRUPTIBLE; \ | |
1003 | schedule(); \ | |
1004 | } while (1) | |
1005 | ||
1006 | /* | |
1007 | * is_journal_abort | |
1008 | * | |
f7f4bccb | 1009 | * Simple test wrapper function to test the JBD2_ABORT state flag. This |
470decc6 DK |
1010 | * bit, when set, indicates that we have had a fatal error somewhere, |
1011 | * either inside the journaling layer or indicated to us by the client | |
1012 | * (eg. ext3), and that we and should not commit any further | |
1013 | * transactions. | |
1014 | */ | |
1015 | ||
1016 | static inline int is_journal_aborted(journal_t *journal) | |
1017 | { | |
f7f4bccb | 1018 | return journal->j_flags & JBD2_ABORT; |
470decc6 DK |
1019 | } |
1020 | ||
1021 | static inline int is_handle_aborted(handle_t *handle) | |
1022 | { | |
1023 | if (handle->h_aborted) | |
1024 | return 1; | |
1025 | return is_journal_aborted(handle->h_transaction->t_journal); | |
1026 | } | |
1027 | ||
f7f4bccb | 1028 | static inline void jbd2_journal_abort_handle(handle_t *handle) |
470decc6 DK |
1029 | { |
1030 | handle->h_aborted = 1; | |
1031 | } | |
1032 | ||
1033 | #endif /* __KERNEL__ */ | |
1034 | ||
1035 | /* Comparison functions for transaction IDs: perform comparisons using | |
1036 | * modulo arithmetic so that they work over sequence number wraps. */ | |
1037 | ||
1038 | static inline int tid_gt(tid_t x, tid_t y) | |
1039 | { | |
1040 | int difference = (x - y); | |
1041 | return (difference > 0); | |
1042 | } | |
1043 | ||
1044 | static inline int tid_geq(tid_t x, tid_t y) | |
1045 | { | |
1046 | int difference = (x - y); | |
1047 | return (difference >= 0); | |
1048 | } | |
1049 | ||
f7f4bccb | 1050 | extern int jbd2_journal_blocks_per_page(struct inode *inode); |
b517bea1 | 1051 | extern size_t journal_tag_bytes(journal_t *journal); |
470decc6 DK |
1052 | |
1053 | /* | |
1054 | * Return the minimum number of blocks which must be free in the journal | |
1055 | * before a new transaction may be started. Must be called under j_state_lock. | |
1056 | */ | |
1057 | static inline int jbd_space_needed(journal_t *journal) | |
1058 | { | |
1059 | int nblocks = journal->j_max_transaction_buffers; | |
1060 | if (journal->j_committing_transaction) | |
1061 | nblocks += journal->j_committing_transaction-> | |
1062 | t_outstanding_credits; | |
1063 | return nblocks; | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * Definitions which augment the buffer_head layer | |
1068 | */ | |
1069 | ||
1070 | /* journaling buffer types */ | |
1071 | #define BJ_None 0 /* Not journaled */ | |
1072 | #define BJ_SyncData 1 /* Normal data: flush before commit */ | |
1073 | #define BJ_Metadata 2 /* Normal journaled metadata */ | |
1074 | #define BJ_Forget 3 /* Buffer superseded by this transaction */ | |
1075 | #define BJ_IO 4 /* Buffer is for temporary IO use */ | |
1076 | #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ | |
1077 | #define BJ_LogCtl 6 /* Buffer contains log descriptors */ | |
1078 | #define BJ_Reserved 7 /* Buffer is reserved for access by journal */ | |
1079 | #define BJ_Locked 8 /* Locked for I/O during commit */ | |
1080 | #define BJ_Types 9 | |
1081 | ||
1082 | extern int jbd_blocks_per_page(struct inode *inode); | |
1083 | ||
1084 | #ifdef __KERNEL__ | |
1085 | ||
1086 | #define buffer_trace_init(bh) do {} while (0) | |
1087 | #define print_buffer_fields(bh) do {} while (0) | |
1088 | #define print_buffer_trace(bh) do {} while (0) | |
1089 | #define BUFFER_TRACE(bh, info) do {} while (0) | |
1090 | #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) | |
1091 | #define JBUFFER_TRACE(jh, info) do {} while (0) | |
1092 | ||
1093 | #endif /* __KERNEL__ */ | |
1094 | ||
cd02ff0b | 1095 | #endif /* _LINUX_JBD2_H */ |