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 #if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__)
20
21 /* Allow this file to be included directly into e2fsprogs */
22 #ifndef __KERNEL__
23 #include "jfs_compat.h"
24 #define JFS_DEBUG
25 #define jfs_debug jbd_debug
26 #else
27
28 #include <linux/journal-head.h>
29 #include <linux/stddef.h>
30 #include <asm/semaphore.h>
31 #endif
32
33 #ifndef __GNUC__
34 #define __FUNCTION__ ""
35 #endif
36
37 #define journal_oom_retry 1
38
39 #ifdef __STDC__
40 #ifdef CONFIG_JBD_DEBUG
41 /*
42 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
43 * consistency checks. By default we don't do this unless
44 * CONFIG_JBD_DEBUG is on.
45 */
46 #define JBD_EXPENSIVE_CHECKING
47 extern int journal_enable_debug;
48
49 #define jbd_debug(n, f, a...) \
50 do { \
51 if ((n) <= journal_enable_debug) { \
52 printk (KERN_DEBUG "(%s, %d): %s: ", \
53 __FILE__, __LINE__, __FUNCTION__); \
54 printk (f, ## a); \
55 } \
56 } while (0)
57 #else
58 #ifdef __GNUC__
59 #define jbd_debug(f, a...) /**/
60 #else
61 #define jbd_debug(f, ...) /**/
62 #endif
63 #endif
64 #else
65 #define jbd_debug(x) /* AIX doesn't do STDC */
66 #endif
67
68 extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry);
69 #define jbd_kmalloc(size, flags) \
70 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
71 #define jbd_rep_kmalloc(size, flags) \
72 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
73
74 #define JFS_MIN_JOURNAL_BLOCKS 1024
75
76 #ifdef __KERNEL__
77 typedef struct handle_s handle_t; /* Atomic operation type */
78 typedef struct journal_s journal_t; /* Journal control structure */
79 #endif
80
81 /*
82 * Internal structures used by the logging mechanism:
83 */
84
85 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
86
87 /*
88 * On-disk structures
89 */
90
91 /*
92 * Descriptor block types:
93 */
94
95 #define JFS_DESCRIPTOR_BLOCK 1
96 #define JFS_COMMIT_BLOCK 2
97 #define JFS_SUPERBLOCK_V1 3
98 #define JFS_SUPERBLOCK_V2 4
99 #define JFS_REVOKE_BLOCK 5
100
101 /*
102 * Standard header for all descriptor blocks:
103 */
104 typedef struct journal_header_s
105 {
106 __u32 h_magic;
107 __u32 h_blocktype;
108 __u32 h_sequence;
109 } journal_header_t;
110
111 /*
112 * Checksum types.
113 */
114 #define JBD2_CRC32_CHKSUM 1
115 #define JBD2_MD5_CHKSUM 2
116 #define JBD2_SHA1_CHKSUM 3
117
118 #define JBD2_CRC32_CHKSUM_SIZE 4
119
120 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
121 /*
122 * Commit block header for storing transactional checksums:
123 */
124 struct commit_header {
125 __u32 h_magic;
126 __u32 h_blocktype;
127 __u32 h_sequence;
128 unsigned char h_chksum_type;
129 unsigned char h_chksum_size;
130 unsigned char h_padding[2];
131 __u32 h_chksum[JBD2_CHECKSUM_BYTES];
132 __u64 h_commit_sec;
133 __u32 h_commit_nsec;
134 };
135
136 /*
137 * The block tag: used to describe a single buffer in the journal
138 */
139 typedef struct journal_block_tag_s
140 {
141 __u32 t_blocknr; /* The on-disk block number */
142 __u32 t_flags; /* See below */
143 __u32 t_blocknr_high; /* most-significant high 32bits. */
144 } journal_block_tag_t;
145
146 #define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
147 #define JBD_TAG_SIZE32 (8)
148
149 /*
150 * The revoke descriptor: used on disk to describe a series of blocks to
151 * be revoked from the log
152 */
153 typedef struct journal_revoke_header_s
154 {
155 journal_header_t r_header;
156 int r_count; /* Count of bytes used in the block */
157 } journal_revoke_header_t;
158
159
160 /* Definitions for the journal tag flags word: */
161 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
162 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
163 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
164 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
165
166
167 /*
168 * The journal superblock. All fields are in big-endian byte order.
169 */
170 typedef struct journal_superblock_s
171 {
172 /* 0x0000 */
173 journal_header_t s_header;
174
175 /* 0x000C */
176 /* Static information describing the journal */
177 __u32 s_blocksize; /* journal device blocksize */
178 __u32 s_maxlen; /* total blocks in journal file */
179 __u32 s_first; /* first block of log information */
180
181 /* 0x0018 */
182 /* Dynamic information describing the current state of the log */
183 __u32 s_sequence; /* first commit ID expected in log */
184 __u32 s_start; /* blocknr of start of log */
185
186 /* 0x0020 */
187 /* Error value, as set by journal_abort(). */
188 __s32 s_errno;
189
190 /* 0x0024 */
191 /* Remaining fields are only valid in a version-2 superblock */
192 __u32 s_feature_compat; /* compatible feature set */
193 __u32 s_feature_incompat; /* incompatible feature set */
194 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
195 /* 0x0030 */
196 __u8 s_uuid[16]; /* 128-bit uuid for journal */
197
198 /* 0x0040 */
199 __u32 s_nr_users; /* Nr of filesystems sharing log */
200
201 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
202
203 /* 0x0048 */
204 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
205 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
206
207 /* 0x0050 */
208 __u32 s_padding[44];
209
210 /* 0x0100 */
211 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
212 /* 0x0400 */
213 } journal_superblock_t;
214
215 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
216 ((j)->j_format_version >= 2 && \
217 ((j)->j_superblock->s_feature_compat & ext2fs_cpu_to_be32((mask))))
218 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
219 ((j)->j_format_version >= 2 && \
220 ((j)->j_superblock->s_feature_ro_compat & ext2fs_cpu_to_be32((mask))))
221 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
222 ((j)->j_format_version >= 2 && \
223 ((j)->j_superblock->s_feature_incompat & ext2fs_cpu_to_be32((mask))))
224
225 #define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001
226
227 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
228
229 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
230 #define JFS_FEATURE_INCOMPAT_64BIT 0x00000002
231 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
232
233 /* Features known to this kernel version: */
234 #define JFS_KNOWN_COMPAT_FEATURES 0
235 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
236 #define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE|\
237 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT|\
238 JFS_FEATURE_INCOMPAT_64BIT)
239
240 #ifdef __KERNEL__
241
242 #include <linux/fs.h>
243 #include <linux/sched.h>
244
245 #define JBD_ASSERTIONS
246 #ifdef JBD_ASSERTIONS
247 #define J_ASSERT(assert) \
248 do { \
249 if (!(assert)) { \
250 printk (KERN_EMERG \
251 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
252 __FUNCTION__, __FILE__, __LINE__, # assert); \
253 BUG(); \
254 } \
255 } while (0)
256
257 #if defined(CONFIG_BUFFER_DEBUG)
258 void buffer_assertion_failure(struct buffer_head *bh);
259 #define J_ASSERT_BH(bh, expr) \
260 do { \
261 if (!(expr)) \
262 buffer_assertion_failure(bh); \
263 J_ASSERT(expr); \
264 } while (0)
265 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
266 #else
267 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
268 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
269 #endif
270
271 #else
272 #define J_ASSERT(assert)
273 #endif /* JBD_ASSERTIONS */
274
275 enum jbd_state_bits {
276 BH_JWrite
277 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
278 BH_Freed, /* 1 if buffer has been freed (truncated) */
279 BH_Revoked, /* 1 if buffer has been revoked from the log */
280 BH_RevokeValid, /* 1 if buffer revoked flag is valid */
281 BH_JBDDirty, /* 1 if buffer is dirty but journaled */
282 };
283
284 /* Return true if the buffer is one which JBD is managing */
buffer_jbd(struct buffer_head * bh)285 static inline int buffer_jbd(struct buffer_head *bh)
286 {
287 return __buffer_state(bh, JBD);
288 }
289
jh2bh(struct journal_head * jh)290 static inline struct buffer_head *jh2bh(struct journal_head *jh)
291 {
292 return jh->b_bh;
293 }
294
bh2jh(struct buffer_head * bh)295 static inline struct journal_head *bh2jh(struct buffer_head *bh)
296 {
297 return bh->b_private;
298 }
299
300 struct jbd_revoke_table_s;
301
302 /* The handle_t type represents a single atomic update being performed
303 * by some process. All filesystem modifications made by the process go
304 * through this handle. Recursive operations (such as quota operations)
305 * are gathered into a single update.
306 *
307 * The buffer credits field is used to account for journaled buffers
308 * being modified by the running process. To ensure that there is
309 * enough log space for all outstanding operations, we need to limit the
310 * number of outstanding buffers possible at any time. When the
311 * operation completes, any buffer credits not used are credited back to
312 * the transaction, so that at all times we know how many buffers the
313 * outstanding updates on a transaction might possibly touch. */
314
315 struct handle_s
316 {
317 /* Which compound transaction is this update a part of? */
318 transaction_t * h_transaction;
319
320 /* Number of remaining buffers we are allowed to dirty: */
321 int h_buffer_credits;
322
323 /* Reference count on this handle */
324 int h_ref;
325
326 /* Field for caller's use to track errors through large fs
327 operations */
328 int h_err;
329
330 /* Flags */
331 unsigned int h_sync: 1; /* sync-on-close */
332 unsigned int h_jdata: 1; /* force data journaling */
333 unsigned int h_aborted: 1; /* fatal error on handle */
334 };
335
336
337 /* The transaction_t type is the guts of the journaling mechanism. It
338 * tracks a compound transaction through its various states:
339 *
340 * RUNNING: accepting new updates
341 * LOCKED: Updates still running but we don't accept new ones
342 * RUNDOWN: Updates are tidying up but have finished requesting
343 * new buffers to modify (state not used for now)
344 * FLUSH: All updates complete, but we are still writing to disk
345 * COMMIT: All data on disk, writing commit record
346 * FINISHED: We still have to keep the transaction for checkpointing.
347 *
348 * The transaction keeps track of all of the buffers modified by a
349 * running transaction, and all of the buffers committed but not yet
350 * flushed to home for finished transactions.
351 */
352
353 struct transaction_s
354 {
355 /* Pointer to the journal for this transaction. */
356 journal_t * t_journal;
357
358 /* Sequence number for this transaction */
359 tid_t t_tid;
360
361 /* Transaction's current state */
362 enum {
363 T_RUNNING,
364 T_LOCKED,
365 T_RUNDOWN,
366 T_FLUSH,
367 T_COMMIT,
368 T_FINISHED
369 } t_state;
370
371 /* Where in the log does this transaction's commit start? */
372 unsigned long t_log_start;
373
374 /* Doubly-linked circular list of all inodes owned by this
375 transaction */ /* AKPM: unused */
376 struct inode * t_ilist;
377
378 /* Number of buffers on the t_buffers list */
379 int t_nr_buffers;
380
381 /* Doubly-linked circular list of all buffers reserved but not
382 yet modified by this transaction */
383 struct journal_head * t_reserved_list;
384
385 /* Doubly-linked circular list of all metadata buffers owned by this
386 transaction */
387 struct journal_head * t_buffers;
388
389 /*
390 * Doubly-linked circular list of all data buffers still to be
391 * flushed before this transaction can be committed.
392 * Protected by journal_datalist_lock.
393 */
394 struct journal_head * t_sync_datalist;
395
396 /*
397 * Doubly-linked circular list of all writepage data buffers
398 * still to be written before this transaction can be committed.
399 * Protected by journal_datalist_lock.
400 */
401 struct journal_head * t_async_datalist;
402
403 /* Doubly-linked circular list of all forget buffers (superceded
404 buffers which we can un-checkpoint once this transaction
405 commits) */
406 struct journal_head * t_forget;
407
408 /*
409 * Doubly-linked circular list of all buffers still to be
410 * flushed before this transaction can be checkpointed.
411 */
412 /* Protected by journal_datalist_lock */
413 struct journal_head * t_checkpoint_list;
414
415 /* Doubly-linked circular list of temporary buffers currently
416 undergoing IO in the log */
417 struct journal_head * t_iobuf_list;
418
419 /* Doubly-linked circular list of metadata buffers being
420 shadowed by log IO. The IO buffers on the iobuf list and the
421 shadow buffers on this list match each other one for one at
422 all times. */
423 struct journal_head * t_shadow_list;
424
425 /* Doubly-linked circular list of control buffers being written
426 to the log. */
427 struct journal_head * t_log_list;
428
429 /* Number of outstanding updates running on this transaction */
430 int t_updates;
431
432 /* Number of buffers reserved for use by all handles in this
433 * transaction handle but not yet modified. */
434 int t_outstanding_credits;
435
436 /*
437 * Forward and backward links for the circular list of all
438 * transactions awaiting checkpoint.
439 */
440 /* Protected by journal_datalist_lock */
441 transaction_t *t_cpnext, *t_cpprev;
442
443 /* When will the transaction expire (become due for commit), in
444 * jiffies ? */
445 unsigned long t_expires;
446
447 /* How many handles used this transaction? */
448 int t_handle_count;
449 };
450
451
452 /* The journal_t maintains all of the journaling state information for a
453 * single filesystem. It is linked to from the fs superblock structure.
454 *
455 * We use the journal_t to keep track of all outstanding transaction
456 * activity on the filesystem, and to manage the state of the log
457 * writing process. */
458
459 struct journal_s
460 {
461 /* General journaling state flags */
462 unsigned long j_flags;
463
464 /* Is there an outstanding uncleared error on the journal (from
465 * a prior abort)? */
466 int j_errno;
467
468 /* The superblock buffer */
469 struct buffer_head * j_sb_buffer;
470 journal_superblock_t * j_superblock;
471
472 /* Version of the superblock format */
473 int j_format_version;
474
475 /* Number of processes waiting to create a barrier lock */
476 int j_barrier_count;
477
478 /* The barrier lock itself */
479 struct semaphore j_barrier;
480
481 /* Transactions: The current running transaction... */
482 transaction_t * j_running_transaction;
483
484 /* ... the transaction we are pushing to disk ... */
485 transaction_t * j_committing_transaction;
486
487 /* ... and a linked circular list of all transactions waiting
488 * for checkpointing. */
489 /* Protected by journal_datalist_lock */
490 transaction_t * j_checkpoint_transactions;
491
492 /* Wait queue for waiting for a locked transaction to start
493 committing, or for a barrier lock to be released */
494 wait_queue_head_t j_wait_transaction_locked;
495
496 /* Wait queue for waiting for checkpointing to complete */
497 wait_queue_head_t j_wait_logspace;
498
499 /* Wait queue for waiting for commit to complete */
500 wait_queue_head_t j_wait_done_commit;
501
502 /* Wait queue to trigger checkpointing */
503 wait_queue_head_t j_wait_checkpoint;
504
505 /* Wait queue to trigger commit */
506 wait_queue_head_t j_wait_commit;
507
508 /* Wait queue to wait for updates to complete */
509 wait_queue_head_t j_wait_updates;
510
511 /* Semaphore for locking against concurrent checkpoints */
512 struct semaphore j_checkpoint_sem;
513
514 /* The main journal lock, used by lock_journal() */
515 struct semaphore j_sem;
516
517 /* Journal head: identifies the first unused block in the journal. */
518 unsigned long j_head;
519
520 /* Journal tail: identifies the oldest still-used block in the
521 * journal. */
522 unsigned long j_tail;
523
524 /* Journal free: how many free blocks are there in the journal? */
525 unsigned long j_free;
526
527 /* Journal start and end: the block numbers of the first usable
528 * block and one beyond the last usable block in the journal. */
529 unsigned long j_first, j_last;
530
531 /* Device, blocksize and starting block offset for the location
532 * where we store the journal. */
533 kdev_t j_dev;
534 int j_blocksize;
535 unsigned int j_blk_offset;
536
537 /* Device which holds the client fs. For internal journal this
538 * will be equal to j_dev. */
539 kdev_t j_fs_dev;
540
541 /* Total maximum capacity of the journal region on disk. */
542 unsigned int j_maxlen;
543
544 /* Optional inode where we store the journal. If present, all
545 * journal block numbers are mapped into this inode via
546 * bmap(). */
547 struct inode * j_inode;
548
549 /* Sequence number of the oldest transaction in the log */
550 tid_t j_tail_sequence;
551 /* Sequence number of the next transaction to grant */
552 tid_t j_transaction_sequence;
553 /* Sequence number of the most recently committed transaction */
554 tid_t j_commit_sequence;
555 /* Sequence number of the most recent transaction wanting commit */
556 tid_t j_commit_request;
557
558 /* Journal uuid: identifies the object (filesystem, LVM volume
559 * etc) backed by this journal. This will eventually be
560 * replaced by an array of uuids, allowing us to index multiple
561 * devices within a single journal and to perform atomic updates
562 * across them. */
563
564 __u8 j_uuid[16];
565
566 /* Pointer to the current commit thread for this journal */
567 struct task_struct * j_task;
568
569 /* Maximum number of metadata buffers to allow in a single
570 * compound commit transaction */
571 int j_max_transaction_buffers;
572
573 /* What is the maximum transaction lifetime before we begin a
574 * commit? */
575 unsigned long j_commit_interval;
576
577 /* The timer used to wakeup the commit thread: */
578 struct timer_list * j_commit_timer;
579 int j_commit_timer_active;
580
581 /* Link all journals together - system-wide */
582 struct list_head j_all_journals;
583
584 /* The revoke table: maintains the list of revoked blocks in the
585 current transaction. */
586 struct jbd_revoke_table_s *j_revoke;
587
588 /* Failed journal commit ID */
589 unsigned int j_failed_commit;
590 };
591
592 /*
593 * Journal flag definitions
594 */
595 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
596 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
597 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
598 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
599 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
600
601 /*
602 * Function declarations for the journaling transaction and buffer
603 * management
604 */
605
606 /* Filing buffers */
607 extern void __journal_unfile_buffer(struct journal_head *);
608 extern void journal_unfile_buffer(struct journal_head *);
609 extern void __journal_refile_buffer(struct journal_head *);
610 extern void journal_refile_buffer(struct journal_head *);
611 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
612 extern void __journal_free_buffer(struct journal_head *bh);
613 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
614 extern void __journal_clean_data_list(transaction_t *transaction);
615
616 /* Log buffer allocation */
617 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
618 extern unsigned long journal_next_log_block(journal_t *);
619
620 /* Commit management */
621 extern void journal_commit_transaction(journal_t *);
622
623 /* Checkpoint list management */
624 int __journal_clean_checkpoint_list(journal_t *journal);
625 extern void journal_remove_checkpoint(struct journal_head *);
626 extern void __journal_remove_checkpoint(struct journal_head *);
627 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
628 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
629
630 /* Buffer IO */
631 extern int
632 journal_write_metadata_buffer(transaction_t *transaction,
633 struct journal_head *jh_in,
634 struct journal_head **jh_out,
635 int blocknr);
636
637 /* Transaction locking */
638 extern void __wait_on_journal (journal_t *);
639
640 /*
641 * Journal locking.
642 *
643 * We need to lock the journal during transaction state changes so that
644 * nobody ever tries to take a handle on the running transaction while
645 * we are in the middle of moving it to the commit phase.
646 *
647 * Note that the locking is completely interrupt unsafe. We never touch
648 * journal structures from interrupts.
649 *
650 * In 2.2, the BKL was required for lock_journal. This is no longer
651 * the case.
652 */
653
lock_journal(journal_t * journal)654 static inline void lock_journal(journal_t *journal)
655 {
656 down(&journal->j_sem);
657 }
658
659 /* This returns zero if we acquired the semaphore */
try_lock_journal(journal_t * journal)660 static inline int try_lock_journal(journal_t * journal)
661 {
662 return down_trylock(&journal->j_sem);
663 }
664
unlock_journal(journal_t * journal)665 static inline void unlock_journal(journal_t * journal)
666 {
667 up(&journal->j_sem);
668 }
669
670
journal_current_handle(void)671 static inline handle_t *journal_current_handle(void)
672 {
673 return current->journal_info;
674 }
675
676 /* The journaling code user interface:
677 *
678 * Create and destroy handles
679 * Register buffer modifications against the current transaction.
680 */
681
682 extern handle_t *journal_start(journal_t *, int nblocks);
683 extern handle_t *journal_try_start(journal_t *, int nblocks);
684 extern int journal_restart (handle_t *, int nblocks);
685 extern int journal_extend (handle_t *, int nblocks);
686 extern int journal_get_write_access (handle_t *, struct buffer_head *);
687 extern int journal_get_create_access (handle_t *, struct buffer_head *);
688 extern int journal_get_undo_access (handle_t *, struct buffer_head *);
689 extern int journal_dirty_data (handle_t *,
690 struct buffer_head *, int async);
691 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
692 extern void journal_release_buffer (handle_t *, struct buffer_head *);
693 extern void journal_forget (handle_t *, struct buffer_head *);
694 extern void journal_sync_buffer (struct buffer_head *);
695 extern int journal_flushpage(journal_t *, struct page *, unsigned long);
696 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
697 extern int journal_stop(handle_t *);
698 extern int journal_flush (journal_t *);
699
700 extern void journal_lock_updates (journal_t *);
701 extern void journal_unlock_updates (journal_t *);
702
703 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
704 int start, int len, int bsize);
705 extern journal_t * journal_init_inode (struct inode *);
706 extern int journal_update_format (journal_t *);
707 extern int journal_check_used_features
708 (journal_t *, unsigned long, unsigned long, unsigned long);
709 extern int journal_check_available_features
710 (journal_t *, unsigned long, unsigned long, unsigned long);
711 extern int journal_set_features
712 (journal_t *, unsigned long, unsigned long, unsigned long);
713 extern int journal_create (journal_t *);
714 extern int journal_load (journal_t *journal);
715 extern void journal_destroy (journal_t *);
716 extern int journal_recover (journal_t *journal);
717 extern int journal_wipe (journal_t *, int);
718 extern int journal_skip_recovery (journal_t *);
719 extern void journal_update_superblock (journal_t *, int);
720 extern void __journal_abort (journal_t *);
721 extern void journal_abort (journal_t *, int);
722 extern int journal_errno (journal_t *);
723 extern void journal_ack_err (journal_t *);
724 extern int journal_clear_err (journal_t *);
725 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
726 extern int journal_force_commit(journal_t *journal);
727
728 /*
729 * journal_head management
730 */
731 extern struct journal_head
732 *journal_add_journal_head(struct buffer_head *bh);
733 extern void journal_remove_journal_head(struct buffer_head *bh);
734 extern void __journal_remove_journal_head(struct buffer_head *bh);
735 extern void journal_unlock_journal_head(struct journal_head *jh);
736
737 /* Primary revoke support */
738 #define JOURNAL_REVOKE_DEFAULT_HASH 256
739 extern int journal_init_revoke(journal_t *, int);
740 extern void journal_destroy_revoke_caches(void);
741 extern int journal_init_revoke_caches(void);
742
743 extern void journal_destroy_revoke(journal_t *);
744 extern int journal_revoke (handle_t *,
745 unsigned long, struct buffer_head *);
746 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
747 extern void journal_write_revoke_records(journal_t *, transaction_t *);
748
749 /* Recovery revoke support */
750 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
751 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
752 extern void journal_clear_revoke(journal_t *);
753 extern void journal_brelse_array(struct buffer_head *b[], int n);
754
755 /* The log thread user interface:
756 *
757 * Request space in the current transaction, and force transaction commit
758 * transitions on demand.
759 */
760
761 extern int log_space_left (journal_t *); /* Called with journal locked */
762 extern tid_t log_start_commit (journal_t *, transaction_t *);
763 extern void log_wait_commit (journal_t *, tid_t);
764 extern int log_do_checkpoint (journal_t *, int);
765
766 extern void log_wait_for_space(journal_t *, int nblocks);
767 extern void __journal_drop_transaction(journal_t *, transaction_t *);
768 extern int cleanup_journal_tail(journal_t *);
769
770 /* Reduce journal memory usage by flushing */
771 extern void shrink_journal_memory(void);
772
773 /* Debugging code only: */
774
775 #define jbd_ENOSYS() \
776 do { \
777 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
778 current->state = TASK_UNINTERRUPTIBLE; \
779 schedule(); \
780 } while (1)
781
782 /*
783 * is_journal_abort
784 *
785 * Simple test wrapper function to test the JFS_ABORT state flag. This
786 * bit, when set, indicates that we have had a fatal error somewhere,
787 * either inside the journaling layer or indicated to us by the client
788 * (eg. ext3), and that we and should not commit any further
789 * transactions.
790 */
791
is_journal_aborted(journal_t * journal)792 static inline int is_journal_aborted(journal_t *journal)
793 {
794 return journal->j_flags & JFS_ABORT;
795 }
796
is_handle_aborted(handle_t * handle)797 static inline int is_handle_aborted(handle_t *handle)
798 {
799 if (handle->h_aborted)
800 return 1;
801 return is_journal_aborted(handle->h_transaction->t_journal);
802 }
803
journal_abort_handle(handle_t * handle)804 static inline void journal_abort_handle(handle_t *handle)
805 {
806 handle->h_aborted = 1;
807 }
808
809 /* Not all architectures define BUG() */
810 #ifndef BUG
811 #define BUG() do { \
812 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
813 * ((char *) 0) = 0; \
814 } while (0)
815 #endif /* BUG */
816
817 #else
818
819 extern int journal_recover (journal_t *journal);
820 extern int journal_skip_recovery (journal_t *);
821
822 /* Primary revoke support */
823 extern int journal_init_revoke(journal_t *, int);
824 extern void journal_destroy_revoke_caches(void);
825 extern int journal_init_revoke_caches(void);
826
827 /* Recovery revoke support */
828 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
829 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
830 extern void journal_clear_revoke(journal_t *);
831 extern void journal_brelse_array(struct buffer_head *b[], int n);
832
833 extern void journal_destroy_revoke(journal_t *);
834 #endif /* __KERNEL__ */
835
836 static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused));
837 static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused));
838
839 /* Comparison functions for transaction IDs: perform comparisons using
840 * modulo arithmetic so that they work over sequence number wraps. */
841
tid_gt(tid_t x,tid_t y)842 static inline int tid_gt(tid_t x, tid_t y)
843 {
844 int difference = (x - y);
845 return (difference > 0);
846 }
847
tid_geq(tid_t x,tid_t y)848 static inline int tid_geq(tid_t x, tid_t y)
849 {
850 int difference = (x - y);
851 return (difference >= 0);
852 }
853
854 extern int journal_blocks_per_page(struct inode *inode);
855
856 /*
857 * Definitions which augment the buffer_head layer
858 */
859
860 /* journaling buffer types */
861 #define BJ_None 0 /* Not journaled */
862 #define BJ_SyncData 1 /* Normal data: flush before commit */
863 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
864 #define BJ_Metadata 3 /* Normal journaled metadata */
865 #define BJ_Forget 4 /* Buffer superceded by this transaction */
866 #define BJ_IO 5 /* Buffer is for temporary IO use */
867 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
868 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
869 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
870 #define BJ_Types 9
871
872 extern int jbd_blocks_per_page(struct inode *inode);
873
874 #ifdef __KERNEL__
875
876 extern spinlock_t jh_splice_lock;
877 /*
878 * Once `expr1' has been found true, take jh_splice_lock
879 * and then reevaluate everything.
880 */
881 #define SPLICE_LOCK(expr1, expr2) \
882 ({ \
883 int ret = (expr1); \
884 if (ret) { \
885 spin_lock(&jh_splice_lock); \
886 ret = (expr1) && (expr2); \
887 spin_unlock(&jh_splice_lock); \
888 } \
889 ret; \
890 })
891
892 /*
893 * A number of buffer state predicates. They test for
894 * buffer_jbd() because they are used in core kernel code.
895 *
896 * These will be racy on SMP unless we're *sure* that the
897 * buffer won't be detached from the journalling system
898 * in parallel.
899 */
900
901 /* Return true if the buffer is on journal list `list' */
buffer_jlist_eq(struct buffer_head * bh,int list)902 static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
903 {
904 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
905 }
906
907 /* Return true if this bufer is dirty wrt the journal */
buffer_jdirty(struct buffer_head * bh)908 static inline int buffer_jdirty(struct buffer_head *bh)
909 {
910 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
911 }
912
913 /* Return true if it's a data buffer which journalling is managing */
buffer_jbd_data(struct buffer_head * bh)914 static inline int buffer_jbd_data(struct buffer_head *bh)
915 {
916 return SPLICE_LOCK(buffer_jbd(bh),
917 bh2jh(bh)->b_jlist == BJ_SyncData ||
918 bh2jh(bh)->b_jlist == BJ_AsyncData);
919 }
920
921 #ifdef CONFIG_SMP
922 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
923 #else
924 #define assert_spin_locked(lock) do {} while(0)
925 #endif
926
927 #define buffer_trace_init(bh) do {} while (0)
928 #define print_buffer_fields(bh) do {} while (0)
929 #define print_buffer_trace(bh) do {} while (0)
930 #define BUFFER_TRACE(bh, info) do {} while (0)
931 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
932 #define JBUFFER_TRACE(jh, info) do {} while (0)
933
934 #endif /* __KERNEL__ */
935
936 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
937
938 /*
939 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
940 * go here.
941 */
942
943 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
944
945 #define J_ASSERT(expr) do {} while (0)
946 #define J_ASSERT_BH(bh, expr) do {} while (0)
947 #define buffer_jbd(bh) 0
948 #define buffer_jlist_eq(bh, val) 0
949 #define journal_buffer_journal_lru(bh) 0
950
951 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
952 #endif /* _LINUX_JBD_H */
953