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 /*
113 * The block tag: used to describe a single buffer in the journal
114 */
115 typedef struct journal_block_tag_s
116 {
117 __u32 t_blocknr; /* The on-disk block number */
118 __u32 t_flags; /* See below */
119 } journal_block_tag_t;
120
121 /*
122 * The revoke descriptor: used on disk to describe a series of blocks to
123 * be revoked from the log
124 */
125 typedef struct journal_revoke_header_s
126 {
127 journal_header_t r_header;
128 int r_count; /* Count of bytes used in the block */
129 } journal_revoke_header_t;
130
131
132 /* Definitions for the journal tag flags word: */
133 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
134 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
135 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
136 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
137
138
139 /*
140 * The journal superblock. All fields are in big-endian byte order.
141 */
142 typedef struct journal_superblock_s
143 {
144 /* 0x0000 */
145 journal_header_t s_header;
146
147 /* 0x000C */
148 /* Static information describing the journal */
149 __u32 s_blocksize; /* journal device blocksize */
150 __u32 s_maxlen; /* total blocks in journal file */
151 __u32 s_first; /* first block of log information */
152
153 /* 0x0018 */
154 /* Dynamic information describing the current state of the log */
155 __u32 s_sequence; /* first commit ID expected in log */
156 __u32 s_start; /* blocknr of start of log */
157
158 /* 0x0020 */
159 /* Error value, as set by journal_abort(). */
160 __s32 s_errno;
161
162 /* 0x0024 */
163 /* Remaining fields are only valid in a version-2 superblock */
164 __u32 s_feature_compat; /* compatible feature set */
165 __u32 s_feature_incompat; /* incompatible feature set */
166 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
167 /* 0x0030 */
168 __u8 s_uuid[16]; /* 128-bit uuid for journal */
169
170 /* 0x0040 */
171 __u32 s_nr_users; /* Nr of filesystems sharing log */
172
173 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
174
175 /* 0x0048 */
176 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
177 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
178
179 /* 0x0050 */
180 __u32 s_padding[44];
181
182 /* 0x0100 */
183 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
184 /* 0x0400 */
185 } journal_superblock_t;
186
187 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
188 ((j)->j_format_version >= 2 && \
189 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
190 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
191 ((j)->j_format_version >= 2 && \
192 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
193 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
194 ((j)->j_format_version >= 2 && \
195 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
196
197 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
198
199 /* Features known to this kernel version: */
200 #define JFS_KNOWN_COMPAT_FEATURES 0
201 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
202 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
203
204 #ifdef __KERNEL__
205
206 #include <linux/fs.h>
207 #include <linux/sched.h>
208
209 #define JBD_ASSERTIONS
210 #ifdef JBD_ASSERTIONS
211 #define J_ASSERT(assert) \
212 do { \
213 if (!(assert)) { \
214 printk (KERN_EMERG \
215 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
216 __FUNCTION__, __FILE__, __LINE__, # assert); \
217 BUG(); \
218 } \
219 } while (0)
220
221 #if defined(CONFIG_BUFFER_DEBUG)
222 void buffer_assertion_failure(struct buffer_head *bh);
223 #define J_ASSERT_BH(bh, expr) \
224 do { \
225 if (!(expr)) \
226 buffer_assertion_failure(bh); \
227 J_ASSERT(expr); \
228 } while (0)
229 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
230 #else
231 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
232 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
233 #endif
234
235 #else
236 #define J_ASSERT(assert)
237 #endif /* JBD_ASSERTIONS */
238
239 enum jbd_state_bits {
240 BH_JWrite
241 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
242 BH_Freed, /* 1 if buffer has been freed (truncated) */
243 BH_Revoked, /* 1 if buffer has been revoked from the log */
244 BH_RevokeValid, /* 1 if buffer revoked flag is valid */
245 BH_JBDDirty, /* 1 if buffer is dirty but journaled */
246 };
247
248 /* Return true if the buffer is one which JBD is managing */
buffer_jbd(struct buffer_head * bh)249 static inline int buffer_jbd(struct buffer_head *bh)
250 {
251 return __buffer_state(bh, JBD);
252 }
253
jh2bh(struct journal_head * jh)254 static inline struct buffer_head *jh2bh(struct journal_head *jh)
255 {
256 return jh->b_bh;
257 }
258
bh2jh(struct buffer_head * bh)259 static inline struct journal_head *bh2jh(struct buffer_head *bh)
260 {
261 return bh->b_private;
262 }
263
264 struct jbd_revoke_table_s;
265
266 /* The handle_t type represents a single atomic update being performed
267 * by some process. All filesystem modifications made by the process go
268 * through this handle. Recursive operations (such as quota operations)
269 * are gathered into a single update.
270 *
271 * The buffer credits field is used to account for journaled buffers
272 * being modified by the running process. To ensure that there is
273 * enough log space for all outstanding operations, we need to limit the
274 * number of outstanding buffers possible at any time. When the
275 * operation completes, any buffer credits not used are credited back to
276 * the transaction, so that at all times we know how many buffers the
277 * outstanding updates on a transaction might possibly touch. */
278
279 struct handle_s
280 {
281 /* Which compound transaction is this update a part of? */
282 transaction_t * h_transaction;
283
284 /* Number of remaining buffers we are allowed to dirty: */
285 int h_buffer_credits;
286
287 /* Reference count on this handle */
288 int h_ref;
289
290 /* Field for caller's use to track errors through large fs
291 operations */
292 int h_err;
293
294 /* Flags */
295 unsigned int h_sync: 1; /* sync-on-close */
296 unsigned int h_jdata: 1; /* force data journaling */
297 unsigned int h_aborted: 1; /* fatal error on handle */
298 };
299
300
301 /* The transaction_t type is the guts of the journaling mechanism. It
302 * tracks a compound transaction through its various states:
303 *
304 * RUNNING: accepting new updates
305 * LOCKED: Updates still running but we don't accept new ones
306 * RUNDOWN: Updates are tidying up but have finished requesting
307 * new buffers to modify (state not used for now)
308 * FLUSH: All updates complete, but we are still writing to disk
309 * COMMIT: All data on disk, writing commit record
310 * FINISHED: We still have to keep the transaction for checkpointing.
311 *
312 * The transaction keeps track of all of the buffers modified by a
313 * running transaction, and all of the buffers committed but not yet
314 * flushed to home for finished transactions.
315 */
316
317 struct transaction_s
318 {
319 /* Pointer to the journal for this transaction. */
320 journal_t * t_journal;
321
322 /* Sequence number for this transaction */
323 tid_t t_tid;
324
325 /* Transaction's current state */
326 enum {
327 T_RUNNING,
328 T_LOCKED,
329 T_RUNDOWN,
330 T_FLUSH,
331 T_COMMIT,
332 T_FINISHED
333 } t_state;
334
335 /* Where in the log does this transaction's commit start? */
336 unsigned long t_log_start;
337
338 /* Doubly-linked circular list of all inodes owned by this
339 transaction */ /* AKPM: unused */
340 struct inode * t_ilist;
341
342 /* Number of buffers on the t_buffers list */
343 int t_nr_buffers;
344
345 /* Doubly-linked circular list of all buffers reserved but not
346 yet modified by this transaction */
347 struct journal_head * t_reserved_list;
348
349 /* Doubly-linked circular list of all metadata buffers owned by this
350 transaction */
351 struct journal_head * t_buffers;
352
353 /*
354 * Doubly-linked circular list of all data buffers still to be
355 * flushed before this transaction can be committed.
356 * Protected by journal_datalist_lock.
357 */
358 struct journal_head * t_sync_datalist;
359
360 /*
361 * Doubly-linked circular list of all writepage data buffers
362 * still to be written before this transaction can be committed.
363 * Protected by journal_datalist_lock.
364 */
365 struct journal_head * t_async_datalist;
366
367 /* Doubly-linked circular list of all forget buffers (superceded
368 buffers which we can un-checkpoint once this transaction
369 commits) */
370 struct journal_head * t_forget;
371
372 /*
373 * Doubly-linked circular list of all buffers still to be
374 * flushed before this transaction can be checkpointed.
375 */
376 /* Protected by journal_datalist_lock */
377 struct journal_head * t_checkpoint_list;
378
379 /* Doubly-linked circular list of temporary buffers currently
380 undergoing IO in the log */
381 struct journal_head * t_iobuf_list;
382
383 /* Doubly-linked circular list of metadata buffers being
384 shadowed by log IO. The IO buffers on the iobuf list and the
385 shadow buffers on this list match each other one for one at
386 all times. */
387 struct journal_head * t_shadow_list;
388
389 /* Doubly-linked circular list of control buffers being written
390 to the log. */
391 struct journal_head * t_log_list;
392
393 /* Number of outstanding updates running on this transaction */
394 int t_updates;
395
396 /* Number of buffers reserved for use by all handles in this
397 * transaction handle but not yet modified. */
398 int t_outstanding_credits;
399
400 /*
401 * Forward and backward links for the circular list of all
402 * transactions awaiting checkpoint.
403 */
404 /* Protected by journal_datalist_lock */
405 transaction_t *t_cpnext, *t_cpprev;
406
407 /* When will the transaction expire (become due for commit), in
408 * jiffies ? */
409 unsigned long t_expires;
410
411 /* How many handles used this transaction? */
412 int t_handle_count;
413 };
414
415
416 /* The journal_t maintains all of the journaling state information for a
417 * single filesystem. It is linked to from the fs superblock structure.
418 *
419 * We use the journal_t to keep track of all outstanding transaction
420 * activity on the filesystem, and to manage the state of the log
421 * writing process. */
422
423 struct journal_s
424 {
425 /* General journaling state flags */
426 unsigned long j_flags;
427
428 /* Is there an outstanding uncleared error on the journal (from
429 * a prior abort)? */
430 int j_errno;
431
432 /* The superblock buffer */
433 struct buffer_head * j_sb_buffer;
434 journal_superblock_t * j_superblock;
435
436 /* Version of the superblock format */
437 int j_format_version;
438
439 /* Number of processes waiting to create a barrier lock */
440 int j_barrier_count;
441
442 /* The barrier lock itself */
443 struct semaphore j_barrier;
444
445 /* Transactions: The current running transaction... */
446 transaction_t * j_running_transaction;
447
448 /* ... the transaction we are pushing to disk ... */
449 transaction_t * j_committing_transaction;
450
451 /* ... and a linked circular list of all transactions waiting
452 * for checkpointing. */
453 /* Protected by journal_datalist_lock */
454 transaction_t * j_checkpoint_transactions;
455
456 /* Wait queue for waiting for a locked transaction to start
457 committing, or for a barrier lock to be released */
458 wait_queue_head_t j_wait_transaction_locked;
459
460 /* Wait queue for waiting for checkpointing to complete */
461 wait_queue_head_t j_wait_logspace;
462
463 /* Wait queue for waiting for commit to complete */
464 wait_queue_head_t j_wait_done_commit;
465
466 /* Wait queue to trigger checkpointing */
467 wait_queue_head_t j_wait_checkpoint;
468
469 /* Wait queue to trigger commit */
470 wait_queue_head_t j_wait_commit;
471
472 /* Wait queue to wait for updates to complete */
473 wait_queue_head_t j_wait_updates;
474
475 /* Semaphore for locking against concurrent checkpoints */
476 struct semaphore j_checkpoint_sem;
477
478 /* The main journal lock, used by lock_journal() */
479 struct semaphore j_sem;
480
481 /* Journal head: identifies the first unused block in the journal. */
482 unsigned long j_head;
483
484 /* Journal tail: identifies the oldest still-used block in the
485 * journal. */
486 unsigned long j_tail;
487
488 /* Journal free: how many free blocks are there in the journal? */
489 unsigned long j_free;
490
491 /* Journal start and end: the block numbers of the first usable
492 * block and one beyond the last usable block in the journal. */
493 unsigned long j_first, j_last;
494
495 /* Device, blocksize and starting block offset for the location
496 * where we store the journal. */
497 kdev_t j_dev;
498 int j_blocksize;
499 unsigned int j_blk_offset;
500
501 /* Device which holds the client fs. For internal journal this
502 * will be equal to j_dev. */
503 kdev_t j_fs_dev;
504
505 /* Total maximum capacity of the journal region on disk. */
506 unsigned int j_maxlen;
507
508 /* Optional inode where we store the journal. If present, all
509 * journal block numbers are mapped into this inode via
510 * bmap(). */
511 struct inode * j_inode;
512
513 /* Sequence number of the oldest transaction in the log */
514 tid_t j_tail_sequence;
515 /* Sequence number of the next transaction to grant */
516 tid_t j_transaction_sequence;
517 /* Sequence number of the most recently committed transaction */
518 tid_t j_commit_sequence;
519 /* Sequence number of the most recent transaction wanting commit */
520 tid_t j_commit_request;
521
522 /* Journal uuid: identifies the object (filesystem, LVM volume
523 * etc) backed by this journal. This will eventually be
524 * replaced by an array of uuids, allowing us to index multiple
525 * devices within a single journal and to perform atomic updates
526 * across them. */
527
528 __u8 j_uuid[16];
529
530 /* Pointer to the current commit thread for this journal */
531 struct task_struct * j_task;
532
533 /* Maximum number of metadata buffers to allow in a single
534 * compound commit transaction */
535 int j_max_transaction_buffers;
536
537 /* What is the maximum transaction lifetime before we begin a
538 * commit? */
539 unsigned long j_commit_interval;
540
541 /* The timer used to wakeup the commit thread: */
542 struct timer_list * j_commit_timer;
543 int j_commit_timer_active;
544
545 /* Link all journals together - system-wide */
546 struct list_head j_all_journals;
547
548 /* The revoke table: maintains the list of revoked blocks in the
549 current transaction. */
550 struct jbd_revoke_table_s *j_revoke;
551 };
552
553 /*
554 * Journal flag definitions
555 */
556 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
557 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
558 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
559 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
560 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
561
562 /*
563 * Function declarations for the journaling transaction and buffer
564 * management
565 */
566
567 /* Filing buffers */
568 extern void __journal_unfile_buffer(struct journal_head *);
569 extern void journal_unfile_buffer(struct journal_head *);
570 extern void __journal_refile_buffer(struct journal_head *);
571 extern void journal_refile_buffer(struct journal_head *);
572 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
573 extern void __journal_free_buffer(struct journal_head *bh);
574 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
575 extern void __journal_clean_data_list(transaction_t *transaction);
576
577 /* Log buffer allocation */
578 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
579 extern unsigned long journal_next_log_block(journal_t *);
580
581 /* Commit management */
582 extern void journal_commit_transaction(journal_t *);
583
584 /* Checkpoint list management */
585 int __journal_clean_checkpoint_list(journal_t *journal);
586 extern void journal_remove_checkpoint(struct journal_head *);
587 extern void __journal_remove_checkpoint(struct journal_head *);
588 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
589 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
590
591 /* Buffer IO */
592 extern int
593 journal_write_metadata_buffer(transaction_t *transaction,
594 struct journal_head *jh_in,
595 struct journal_head **jh_out,
596 int blocknr);
597
598 /* Transaction locking */
599 extern void __wait_on_journal (journal_t *);
600
601 /*
602 * Journal locking.
603 *
604 * We need to lock the journal during transaction state changes so that
605 * nobody ever tries to take a handle on the running transaction while
606 * we are in the middle of moving it to the commit phase.
607 *
608 * Note that the locking is completely interrupt unsafe. We never touch
609 * journal structures from interrupts.
610 *
611 * In 2.2, the BKL was required for lock_journal. This is no longer
612 * the case.
613 */
614
lock_journal(journal_t * journal)615 static inline void lock_journal(journal_t *journal)
616 {
617 down(&journal->j_sem);
618 }
619
620 /* This returns zero if we acquired the semaphore */
try_lock_journal(journal_t * journal)621 static inline int try_lock_journal(journal_t * journal)
622 {
623 return down_trylock(&journal->j_sem);
624 }
625
unlock_journal(journal_t * journal)626 static inline void unlock_journal(journal_t * journal)
627 {
628 up(&journal->j_sem);
629 }
630
631
journal_current_handle(void)632 static inline handle_t *journal_current_handle(void)
633 {
634 return current->journal_info;
635 }
636
637 /* The journaling code user interface:
638 *
639 * Create and destroy handles
640 * Register buffer modifications against the current transaction.
641 */
642
643 extern handle_t *journal_start(journal_t *, int nblocks);
644 extern handle_t *journal_try_start(journal_t *, int nblocks);
645 extern int journal_restart (handle_t *, int nblocks);
646 extern int journal_extend (handle_t *, int nblocks);
647 extern int journal_get_write_access (handle_t *, struct buffer_head *);
648 extern int journal_get_create_access (handle_t *, struct buffer_head *);
649 extern int journal_get_undo_access (handle_t *, struct buffer_head *);
650 extern int journal_dirty_data (handle_t *,
651 struct buffer_head *, int async);
652 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
653 extern void journal_release_buffer (handle_t *, struct buffer_head *);
654 extern void journal_forget (handle_t *, struct buffer_head *);
655 extern void journal_sync_buffer (struct buffer_head *);
656 extern int journal_flushpage(journal_t *, struct page *, unsigned long);
657 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
658 extern int journal_stop(handle_t *);
659 extern int journal_flush (journal_t *);
660
661 extern void journal_lock_updates (journal_t *);
662 extern void journal_unlock_updates (journal_t *);
663
664 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
665 int start, int len, int bsize);
666 extern journal_t * journal_init_inode (struct inode *);
667 extern int journal_update_format (journal_t *);
668 extern int journal_check_used_features
669 (journal_t *, unsigned long, unsigned long, unsigned long);
670 extern int journal_check_available_features
671 (journal_t *, unsigned long, unsigned long, unsigned long);
672 extern int journal_set_features
673 (journal_t *, unsigned long, unsigned long, unsigned long);
674 extern int journal_create (journal_t *);
675 extern int journal_load (journal_t *journal);
676 extern void journal_destroy (journal_t *);
677 extern int journal_recover (journal_t *journal);
678 extern int journal_wipe (journal_t *, int);
679 extern int journal_skip_recovery (journal_t *);
680 extern void journal_update_superblock (journal_t *, int);
681 extern void __journal_abort (journal_t *);
682 extern void journal_abort (journal_t *, int);
683 extern int journal_errno (journal_t *);
684 extern void journal_ack_err (journal_t *);
685 extern int journal_clear_err (journal_t *);
686 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
687 extern int journal_force_commit(journal_t *journal);
688
689 /*
690 * journal_head management
691 */
692 extern struct journal_head
693 *journal_add_journal_head(struct buffer_head *bh);
694 extern void journal_remove_journal_head(struct buffer_head *bh);
695 extern void __journal_remove_journal_head(struct buffer_head *bh);
696 extern void journal_unlock_journal_head(struct journal_head *jh);
697
698 /* Primary revoke support */
699 #define JOURNAL_REVOKE_DEFAULT_HASH 256
700 extern int journal_init_revoke(journal_t *, int);
701 extern void journal_destroy_revoke_caches(void);
702 extern int journal_init_revoke_caches(void);
703
704 extern void journal_destroy_revoke(journal_t *);
705 extern int journal_revoke (handle_t *,
706 unsigned long, struct buffer_head *);
707 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
708 extern void journal_write_revoke_records(journal_t *, transaction_t *);
709
710 /* Recovery revoke support */
711 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
712 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
713 extern void journal_clear_revoke(journal_t *);
714 extern void journal_brelse_array(struct buffer_head *b[], int n);
715
716 /* The log thread user interface:
717 *
718 * Request space in the current transaction, and force transaction commit
719 * transitions on demand.
720 */
721
722 extern int log_space_left (journal_t *); /* Called with journal locked */
723 extern tid_t log_start_commit (journal_t *, transaction_t *);
724 extern void log_wait_commit (journal_t *, tid_t);
725 extern int log_do_checkpoint (journal_t *, int);
726
727 extern void log_wait_for_space(journal_t *, int nblocks);
728 extern void __journal_drop_transaction(journal_t *, transaction_t *);
729 extern int cleanup_journal_tail(journal_t *);
730
731 /* Reduce journal memory usage by flushing */
732 extern void shrink_journal_memory(void);
733
734 /* Debugging code only: */
735
736 #define jbd_ENOSYS() \
737 do { \
738 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
739 current->state = TASK_UNINTERRUPTIBLE; \
740 schedule(); \
741 } while (1)
742
743 /*
744 * is_journal_abort
745 *
746 * Simple test wrapper function to test the JFS_ABORT state flag. This
747 * bit, when set, indicates that we have had a fatal error somewhere,
748 * either inside the journaling layer or indicated to us by the client
749 * (eg. ext3), and that we and should not commit any further
750 * transactions.
751 */
752
is_journal_aborted(journal_t * journal)753 static inline int is_journal_aborted(journal_t *journal)
754 {
755 return journal->j_flags & JFS_ABORT;
756 }
757
is_handle_aborted(handle_t * handle)758 static inline int is_handle_aborted(handle_t *handle)
759 {
760 if (handle->h_aborted)
761 return 1;
762 return is_journal_aborted(handle->h_transaction->t_journal);
763 }
764
journal_abort_handle(handle_t * handle)765 static inline void journal_abort_handle(handle_t *handle)
766 {
767 handle->h_aborted = 1;
768 }
769
770 /* Not all architectures define BUG() */
771 #ifndef BUG
772 #define BUG() do { \
773 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
774 * ((char *) 0) = 0; \
775 } while (0)
776 #endif /* BUG */
777
778 #else
779
780 extern int journal_recover (journal_t *journal);
781 extern int journal_skip_recovery (journal_t *);
782
783 /* Primary revoke support */
784 extern int journal_init_revoke(journal_t *, int);
785 extern void journal_destroy_revoke_caches(void);
786 extern int journal_init_revoke_caches(void);
787
788 /* Recovery revoke support */
789 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
790 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
791 extern void journal_clear_revoke(journal_t *);
792 extern void journal_brelse_array(struct buffer_head *b[], int n);
793
794 extern void journal_destroy_revoke(journal_t *);
795 #endif /* __KERNEL__ */
796
797 static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused));
798 static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused));
799
800 /* Comparison functions for transaction IDs: perform comparisons using
801 * modulo arithmetic so that they work over sequence number wraps. */
802
tid_gt(tid_t x,tid_t y)803 static inline int tid_gt(tid_t x, tid_t y)
804 {
805 int difference = (x - y);
806 return (difference > 0);
807 }
808
tid_geq(tid_t x,tid_t y)809 static inline int tid_geq(tid_t x, tid_t y)
810 {
811 int difference = (x - y);
812 return (difference >= 0);
813 }
814
815 extern int journal_blocks_per_page(struct inode *inode);
816
817 /*
818 * Definitions which augment the buffer_head layer
819 */
820
821 /* journaling buffer types */
822 #define BJ_None 0 /* Not journaled */
823 #define BJ_SyncData 1 /* Normal data: flush before commit */
824 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
825 #define BJ_Metadata 3 /* Normal journaled metadata */
826 #define BJ_Forget 4 /* Buffer superceded by this transaction */
827 #define BJ_IO 5 /* Buffer is for temporary IO use */
828 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
829 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
830 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
831 #define BJ_Types 9
832
833 extern int jbd_blocks_per_page(struct inode *inode);
834
835 #ifdef __KERNEL__
836
837 extern spinlock_t jh_splice_lock;
838 /*
839 * Once `expr1' has been found true, take jh_splice_lock
840 * and then reevaluate everything.
841 */
842 #define SPLICE_LOCK(expr1, expr2) \
843 ({ \
844 int ret = (expr1); \
845 if (ret) { \
846 spin_lock(&jh_splice_lock); \
847 ret = (expr1) && (expr2); \
848 spin_unlock(&jh_splice_lock); \
849 } \
850 ret; \
851 })
852
853 /*
854 * A number of buffer state predicates. They test for
855 * buffer_jbd() because they are used in core kernel code.
856 *
857 * These will be racy on SMP unless we're *sure* that the
858 * buffer won't be detached from the journalling system
859 * in parallel.
860 */
861
862 /* Return true if the buffer is on journal list `list' */
buffer_jlist_eq(struct buffer_head * bh,int list)863 static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
864 {
865 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
866 }
867
868 /* Return true if this bufer is dirty wrt the journal */
buffer_jdirty(struct buffer_head * bh)869 static inline int buffer_jdirty(struct buffer_head *bh)
870 {
871 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
872 }
873
874 /* Return true if it's a data buffer which journalling is managing */
buffer_jbd_data(struct buffer_head * bh)875 static inline int buffer_jbd_data(struct buffer_head *bh)
876 {
877 return SPLICE_LOCK(buffer_jbd(bh),
878 bh2jh(bh)->b_jlist == BJ_SyncData ||
879 bh2jh(bh)->b_jlist == BJ_AsyncData);
880 }
881
882 #ifdef CONFIG_SMP
883 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
884 #else
885 #define assert_spin_locked(lock) do {} while(0)
886 #endif
887
888 #define buffer_trace_init(bh) do {} while (0)
889 #define print_buffer_fields(bh) do {} while (0)
890 #define print_buffer_trace(bh) do {} while (0)
891 #define BUFFER_TRACE(bh, info) do {} while (0)
892 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
893 #define JBUFFER_TRACE(jh, info) do {} while (0)
894
895 #endif /* __KERNEL__ */
896
897 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
898
899 /*
900 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
901 * go here.
902 */
903
904 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
905
906 #define J_ASSERT(expr) do {} while (0)
907 #define J_ASSERT_BH(bh, expr) do {} while (0)
908 #define buffer_jbd(bh) 0
909 #define buffer_jlist_eq(bh, val) 0
910 #define journal_buffer_journal_lru(bh) 0
911
912 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
913 #endif /* _LINUX_JBD_H */
914