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 /* Allow this file to be included directly into e2fsprogs */
20 #ifndef __KERNEL__
21 #include "jfs_compat.h"
22 #define JFS_DEBUG
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 #include <linux/lockdep.h>
34 #include <linux/slab.h>
35
36 #define journal_oom_retry 1
37
38 /*
39 * Define JBD_PARANOID_IOFAIL to cause a kernel BUG() if ext3 finds
40 * certain classes of error which can occur due to failed IOs. Under
41 * normal use we want ext3 to continue after such errors, because
42 * hardware _can_ fail, but for debugging purposes when running tests on
43 * known-good hardware we may want to trap these errors.
44 */
45 #undef JBD_PARANOID_IOFAIL
46
47 /*
48 * The default maximum commit age, in seconds.
49 */
50 #define JBD_DEFAULT_MAX_COMMIT_AGE 5
51
52 #ifdef CONFIG_JBD_DEBUG
53 /*
54 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
55 * consistency checks. By default we don't do this unless
56 * CONFIG_JBD_DEBUG is on.
57 */
58 #define JBD_EXPENSIVE_CHECKING
59 extern u8 journal_enable_debug;
60
61 #define jbd_debug(n, f, a...) \
62 do { \
63 if ((n) <= journal_enable_debug) { \
64 printk (KERN_DEBUG "(%s, %d): %s: ", \
65 __FILE__, __LINE__, __func__); \
66 printk (f, ## a); \
67 } \
68 } while (0)
69 #else
70 #define jbd_debug(f, a...) /**/
71 #endif
72
jbd_alloc(size_t size,gfp_t flags)73 static inline void *jbd_alloc(size_t size, gfp_t flags)
74 {
75 return (void *)__get_free_pages(flags, get_order(size));
76 }
77
jbd_free(void * ptr,size_t size)78 static inline void jbd_free(void *ptr, size_t size)
79 {
80 free_pages((unsigned long)ptr, get_order(size));
81 };
82
83 #define JFS_MIN_JOURNAL_BLOCKS 1024
84
85
86 /**
87 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
88 *
89 * All filesystem modifications made by the process go
90 * through this handle. Recursive operations (such as quota operations)
91 * are gathered into a single update.
92 *
93 * The buffer credits field is used to account for journaled buffers
94 * being modified by the running process. To ensure that there is
95 * enough log space for all outstanding operations, we need to limit the
96 * number of outstanding buffers possible at any time. When the
97 * operation completes, any buffer credits not used are credited back to
98 * the transaction, so that at all times we know how many buffers the
99 * outstanding updates on a transaction might possibly touch.
100 *
101 * This is an opaque datatype.
102 **/
103 typedef struct handle_s handle_t; /* Atomic operation type */
104
105
106 /**
107 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
108 *
109 * journal_t is linked to from the fs superblock structure.
110 *
111 * We use the journal_t to keep track of all outstanding transaction
112 * activity on the filesystem, and to manage the state of the log
113 * writing process.
114 *
115 * This is an opaque datatype.
116 **/
117 typedef struct journal_s journal_t; /* Journal control structure */
118 #endif
119
120 /*
121 * Internal structures used by the logging mechanism:
122 */
123
124 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
125
126 /*
127 * On-disk structures
128 */
129
130 /*
131 * Descriptor block types:
132 */
133
134 #define JFS_DESCRIPTOR_BLOCK 1
135 #define JFS_COMMIT_BLOCK 2
136 #define JFS_SUPERBLOCK_V1 3
137 #define JFS_SUPERBLOCK_V2 4
138 #define JFS_REVOKE_BLOCK 5
139
140 /*
141 * Standard header for all descriptor blocks:
142 */
143 typedef struct journal_header_s
144 {
145 __be32 h_magic;
146 __be32 h_blocktype;
147 __be32 h_sequence;
148 } journal_header_t;
149
150
151 /*
152 * The block tag: used to describe a single buffer in the journal
153 */
154 typedef struct journal_block_tag_s
155 {
156 __be32 t_blocknr; /* The on-disk block number */
157 __be32 t_flags; /* See below */
158 } journal_block_tag_t;
159
160 /*
161 * The revoke descriptor: used on disk to describe a series of blocks to
162 * be revoked from the log
163 */
164 typedef struct journal_revoke_header_s
165 {
166 journal_header_t r_header;
167 __be32 r_count; /* Count of bytes used in the block */
168 } journal_revoke_header_t;
169
170
171 /* Definitions for the journal tag flags word: */
172 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
173 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
174 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
175 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
176
177
178 /*
179 * The journal superblock. All fields are in big-endian byte order.
180 */
181 typedef struct journal_superblock_s
182 {
183 /* 0x0000 */
184 journal_header_t s_header;
185
186 /* 0x000C */
187 /* Static information describing the journal */
188 __be32 s_blocksize; /* journal device blocksize */
189 __be32 s_maxlen; /* total blocks in journal file */
190 __be32 s_first; /* first block of log information */
191
192 /* 0x0018 */
193 /* Dynamic information describing the current state of the log */
194 __be32 s_sequence; /* first commit ID expected in log */
195 __be32 s_start; /* blocknr of start of log */
196
197 /* 0x0020 */
198 /* Error value, as set by journal_abort(). */
199 __be32 s_errno;
200
201 /* 0x0024 */
202 /* Remaining fields are only valid in a version-2 superblock */
203 __be32 s_feature_compat; /* compatible feature set */
204 __be32 s_feature_incompat; /* incompatible feature set */
205 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
206 /* 0x0030 */
207 __u8 s_uuid[16]; /* 128-bit uuid for journal */
208
209 /* 0x0040 */
210 __be32 s_nr_users; /* Nr of filesystems sharing log */
211
212 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
213
214 /* 0x0048 */
215 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
216 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
217
218 /* 0x0050 */
219 __u32 s_padding[44];
220
221 /* 0x0100 */
222 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
223 /* 0x0400 */
224 } journal_superblock_t;
225
226 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
227 ((j)->j_format_version >= 2 && \
228 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
229 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
230 ((j)->j_format_version >= 2 && \
231 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
232 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
233 ((j)->j_format_version >= 2 && \
234 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
235
236 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
237
238 /* Features known to this kernel version: */
239 #define JFS_KNOWN_COMPAT_FEATURES 0
240 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
241 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
242
243 #ifdef __KERNEL__
244
245 #include <linux/fs.h>
246 #include <linux/sched.h>
247 #include <linux/jbd_common.h>
248
249 #define J_ASSERT(assert) BUG_ON(!(assert))
250
251 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
252 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
253
254 #if defined(JBD_PARANOID_IOFAIL)
255 #define J_EXPECT(expr, why...) J_ASSERT(expr)
256 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
257 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
258 #else
259 #define __journal_expect(expr, why...) \
260 ({ \
261 int val = (expr); \
262 if (!val) { \
263 printk(KERN_ERR \
264 "EXT3-fs unexpected failure: %s;\n",# expr); \
265 printk(KERN_ERR why "\n"); \
266 } \
267 val; \
268 })
269 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
270 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
271 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
272 #endif
273
274 struct jbd_revoke_table_s;
275
276 /**
277 * struct handle_s - this is the concrete type associated with handle_t.
278 * @h_transaction: Which compound transaction is this update a part of?
279 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
280 * @h_ref: Reference count on this handle
281 * @h_err: Field for caller's use to track errors through large fs operations
282 * @h_sync: flag for sync-on-close
283 * @h_jdata: flag to force data journaling
284 * @h_aborted: flag indicating fatal error on handle
285 * @h_lockdep_map: lockdep info for debugging lock problems
286 */
287 struct handle_s
288 {
289 /* Which compound transaction is this update a part of? */
290 transaction_t *h_transaction;
291
292 /* Number of remaining buffers we are allowed to dirty: */
293 int h_buffer_credits;
294
295 /* Reference count on this handle */
296 int h_ref;
297
298 /* Field for caller's use to track errors through large fs */
299 /* operations */
300 int h_err;
301
302 /* Flags [no locking] */
303 unsigned int h_sync: 1; /* sync-on-close */
304 unsigned int h_jdata: 1; /* force data journaling */
305 unsigned int h_aborted: 1; /* fatal error on handle */
306
307 #ifdef CONFIG_DEBUG_LOCK_ALLOC
308 struct lockdep_map h_lockdep_map;
309 #endif
310 };
311
312
313 /* The transaction_t type is the guts of the journaling mechanism. It
314 * tracks a compound transaction through its various states:
315 *
316 * RUNNING: accepting new updates
317 * LOCKED: Updates still running but we don't accept new ones
318 * RUNDOWN: Updates are tidying up but have finished requesting
319 * new buffers to modify (state not used for now)
320 * FLUSH: All updates complete, but we are still writing to disk
321 * COMMIT: All data on disk, writing commit record
322 * FINISHED: We still have to keep the transaction for checkpointing.
323 *
324 * The transaction keeps track of all of the buffers modified by a
325 * running transaction, and all of the buffers committed but not yet
326 * flushed to home for finished transactions.
327 */
328
329 /*
330 * Lock ranking:
331 *
332 * j_list_lock
333 * ->jbd_lock_bh_journal_head() (This is "innermost")
334 *
335 * j_state_lock
336 * ->jbd_lock_bh_state()
337 *
338 * jbd_lock_bh_state()
339 * ->j_list_lock
340 *
341 * j_state_lock
342 * ->t_handle_lock
343 *
344 * j_state_lock
345 * ->j_list_lock (journal_unmap_buffer)
346 *
347 */
348
349 struct transaction_s
350 {
351 /* Pointer to the journal for this transaction. [no locking] */
352 journal_t *t_journal;
353
354 /* Sequence number for this transaction [no locking] */
355 tid_t t_tid;
356
357 /*
358 * Transaction's current state
359 * [no locking - only kjournald alters this]
360 * [j_list_lock] guards transition of a transaction into T_FINISHED
361 * state and subsequent call of __journal_drop_transaction()
362 * FIXME: needs barriers
363 * KLUDGE: [use j_state_lock]
364 */
365 enum {
366 T_RUNNING,
367 T_LOCKED,
368 T_FLUSH,
369 T_COMMIT,
370 T_COMMIT_RECORD,
371 T_FINISHED
372 } t_state;
373
374 /*
375 * Where in the log does this transaction's commit start? [no locking]
376 */
377 unsigned int t_log_start;
378
379 /* Number of buffers on the t_buffers list [j_list_lock] */
380 int t_nr_buffers;
381
382 /*
383 * Doubly-linked circular list of all buffers reserved but not yet
384 * modified by this transaction [j_list_lock]
385 */
386 struct journal_head *t_reserved_list;
387
388 /*
389 * Doubly-linked circular list of all buffers under writeout during
390 * commit [j_list_lock]
391 */
392 struct journal_head *t_locked_list;
393
394 /*
395 * Doubly-linked circular list of all metadata buffers owned by this
396 * transaction [j_list_lock]
397 */
398 struct journal_head *t_buffers;
399
400 /*
401 * Doubly-linked circular list of all data buffers still to be
402 * flushed before this transaction can be committed [j_list_lock]
403 */
404 struct journal_head *t_sync_datalist;
405
406 /*
407 * Doubly-linked circular list of all forget buffers (superseded
408 * buffers which we can un-checkpoint once this transaction commits)
409 * [j_list_lock]
410 */
411 struct journal_head *t_forget;
412
413 /*
414 * Doubly-linked circular list of all buffers still to be flushed before
415 * this transaction can be checkpointed. [j_list_lock]
416 */
417 struct journal_head *t_checkpoint_list;
418
419 /*
420 * Doubly-linked circular list of all buffers submitted for IO while
421 * checkpointing. [j_list_lock]
422 */
423 struct journal_head *t_checkpoint_io_list;
424
425 /*
426 * Doubly-linked circular list of temporary buffers currently undergoing
427 * IO in the log [j_list_lock]
428 */
429 struct journal_head *t_iobuf_list;
430
431 /*
432 * Doubly-linked circular list of metadata buffers being shadowed by log
433 * IO. The IO buffers on the iobuf list and the shadow buffers on this
434 * list match each other one for one at all times. [j_list_lock]
435 */
436 struct journal_head *t_shadow_list;
437
438 /*
439 * Doubly-linked circular list of control buffers being written to the
440 * log. [j_list_lock]
441 */
442 struct journal_head *t_log_list;
443
444 /*
445 * Protects info related to handles
446 */
447 spinlock_t t_handle_lock;
448
449 /*
450 * Number of outstanding updates running on this transaction
451 * [t_handle_lock]
452 */
453 int t_updates;
454
455 /*
456 * Number of buffers reserved for use by all handles in this transaction
457 * handle but not yet modified. [t_handle_lock]
458 */
459 int t_outstanding_credits;
460
461 /*
462 * Forward and backward links for the circular list of all transactions
463 * awaiting checkpoint. [j_list_lock]
464 */
465 transaction_t *t_cpnext, *t_cpprev;
466
467 /*
468 * When will the transaction expire (become due for commit), in jiffies?
469 * [no locking]
470 */
471 unsigned long t_expires;
472
473 /*
474 * When this transaction started, in nanoseconds [no locking]
475 */
476 ktime_t t_start_time;
477
478 /*
479 * How many handles used this transaction? [t_handle_lock]
480 */
481 int t_handle_count;
482 };
483
484 /**
485 * struct journal_s - this is the concrete type associated with journal_t.
486 * @j_flags: General journaling state flags
487 * @j_errno: Is there an outstanding uncleared error on the journal (from a
488 * prior abort)?
489 * @j_sb_buffer: First part of superblock buffer
490 * @j_superblock: Second part of superblock buffer
491 * @j_format_version: Version of the superblock format
492 * @j_state_lock: Protect the various scalars in the journal
493 * @j_barrier_count: Number of processes waiting to create a barrier lock
494 * @j_running_transaction: The current running transaction..
495 * @j_committing_transaction: the transaction we are pushing to disk
496 * @j_checkpoint_transactions: a linked circular list of all transactions
497 * waiting for checkpointing
498 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
499 * to start committing, or for a barrier lock to be released
500 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
501 * @j_wait_done_commit: Wait queue for waiting for commit to complete
502 * @j_wait_checkpoint: Wait queue to trigger checkpointing
503 * @j_wait_commit: Wait queue to trigger commit
504 * @j_wait_updates: Wait queue to wait for updates to complete
505 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
506 * @j_head: Journal head - identifies the first unused block in the journal
507 * @j_tail: Journal tail - identifies the oldest still-used block in the
508 * journal.
509 * @j_free: Journal free - how many free blocks are there in the journal?
510 * @j_first: The block number of the first usable block
511 * @j_last: The block number one beyond the last usable block
512 * @j_dev: Device where we store the journal
513 * @j_blocksize: blocksize for the location where we store the journal.
514 * @j_blk_offset: starting block offset for into the device where we store the
515 * journal
516 * @j_fs_dev: Device which holds the client fs. For internal journal this will
517 * be equal to j_dev
518 * @j_maxlen: Total maximum capacity of the journal region on disk.
519 * @j_list_lock: Protects the buffer lists and internal buffer state.
520 * @j_inode: Optional inode where we store the journal. If present, all journal
521 * block numbers are mapped into this inode via bmap().
522 * @j_tail_sequence: Sequence number of the oldest transaction in the log
523 * @j_transaction_sequence: Sequence number of the next transaction to grant
524 * @j_commit_sequence: Sequence number of the most recently committed
525 * transaction
526 * @j_commit_request: Sequence number of the most recent transaction wanting
527 * commit
528 * @j_commit_waited: Sequence number of the most recent transaction someone
529 * is waiting for to commit.
530 * @j_uuid: Uuid of client object.
531 * @j_task: Pointer to the current commit thread for this journal
532 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
533 * single compound commit transaction
534 * @j_commit_interval: What is the maximum transaction lifetime before we begin
535 * a commit?
536 * @j_commit_timer: The timer used to wakeup the commit thread
537 * @j_revoke_lock: Protect the revoke table
538 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
539 * current transaction.
540 * @j_revoke_table: alternate revoke tables for j_revoke
541 * @j_wbuf: array of buffer_heads for journal_commit_transaction
542 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
543 * number that will fit in j_blocksize
544 * @j_last_sync_writer: most recent pid which did a synchronous write
545 * @j_average_commit_time: the average amount of time in nanoseconds it
546 * takes to commit a transaction to the disk.
547 * @j_private: An opaque pointer to fs-private information.
548 */
549
550 struct journal_s
551 {
552 /* General journaling state flags [j_state_lock] */
553 unsigned long j_flags;
554
555 /*
556 * Is there an outstanding uncleared error on the journal (from a prior
557 * abort)? [j_state_lock]
558 */
559 int j_errno;
560
561 /* The superblock buffer */
562 struct buffer_head *j_sb_buffer;
563 journal_superblock_t *j_superblock;
564
565 /* Version of the superblock format */
566 int j_format_version;
567
568 /*
569 * Protect the various scalars in the journal
570 */
571 spinlock_t j_state_lock;
572
573 /*
574 * Number of processes waiting to create a barrier lock [j_state_lock]
575 */
576 int j_barrier_count;
577
578 /*
579 * Transactions: The current running transaction...
580 * [j_state_lock] [caller holding open handle]
581 */
582 transaction_t *j_running_transaction;
583
584 /*
585 * the transaction we are pushing to disk
586 * [j_state_lock] [caller holding open handle]
587 */
588 transaction_t *j_committing_transaction;
589
590 /*
591 * ... and a linked circular list of all transactions waiting for
592 * checkpointing. [j_list_lock]
593 */
594 transaction_t *j_checkpoint_transactions;
595
596 /*
597 * Wait queue for waiting for a locked transaction to start committing,
598 * or for a barrier lock to be released
599 */
600 wait_queue_head_t j_wait_transaction_locked;
601
602 /* Wait queue for waiting for checkpointing to complete */
603 wait_queue_head_t j_wait_logspace;
604
605 /* Wait queue for waiting for commit to complete */
606 wait_queue_head_t j_wait_done_commit;
607
608 /* Wait queue to trigger checkpointing */
609 wait_queue_head_t j_wait_checkpoint;
610
611 /* Wait queue to trigger commit */
612 wait_queue_head_t j_wait_commit;
613
614 /* Wait queue to wait for updates to complete */
615 wait_queue_head_t j_wait_updates;
616
617 /* Semaphore for locking against concurrent checkpoints */
618 struct mutex j_checkpoint_mutex;
619
620 /*
621 * Journal head: identifies the first unused block in the journal.
622 * [j_state_lock]
623 */
624 unsigned int j_head;
625
626 /*
627 * Journal tail: identifies the oldest still-used block in the journal.
628 * [j_state_lock]
629 */
630 unsigned int j_tail;
631
632 /*
633 * Journal free: how many free blocks are there in the journal?
634 * [j_state_lock]
635 */
636 unsigned int j_free;
637
638 /*
639 * Journal start and end: the block numbers of the first usable block
640 * and one beyond the last usable block in the journal. [j_state_lock]
641 */
642 unsigned int j_first;
643 unsigned int j_last;
644
645 /*
646 * Device, blocksize and starting block offset for the location where we
647 * store the journal.
648 */
649 struct block_device *j_dev;
650 int j_blocksize;
651 unsigned int j_blk_offset;
652
653 /*
654 * Device which holds the client fs. For internal journal this will be
655 * equal to j_dev.
656 */
657 struct block_device *j_fs_dev;
658
659 /* Total maximum capacity of the journal region on disk. */
660 unsigned int j_maxlen;
661
662 /*
663 * Protects the buffer lists and internal buffer state.
664 */
665 spinlock_t j_list_lock;
666
667 /* Optional inode where we store the journal. If present, all */
668 /* journal block numbers are mapped into this inode via */
669 /* bmap(). */
670 struct inode *j_inode;
671
672 /*
673 * Sequence number of the oldest transaction in the log [j_state_lock]
674 */
675 tid_t j_tail_sequence;
676
677 /*
678 * Sequence number of the next transaction to grant [j_state_lock]
679 */
680 tid_t j_transaction_sequence;
681
682 /*
683 * Sequence number of the most recently committed transaction
684 * [j_state_lock].
685 */
686 tid_t j_commit_sequence;
687
688 /*
689 * Sequence number of the most recent transaction wanting commit
690 * [j_state_lock]
691 */
692 tid_t j_commit_request;
693
694 /*
695 * Sequence number of the most recent transaction someone is waiting
696 * for to commit.
697 * [j_state_lock]
698 */
699 tid_t j_commit_waited;
700
701 /*
702 * Journal uuid: identifies the object (filesystem, LVM volume etc)
703 * backed by this journal. This will eventually be replaced by an array
704 * of uuids, allowing us to index multiple devices within a single
705 * journal and to perform atomic updates across them.
706 */
707 __u8 j_uuid[16];
708
709 /* Pointer to the current commit thread for this journal */
710 struct task_struct *j_task;
711
712 /*
713 * Maximum number of metadata buffers to allow in a single compound
714 * commit transaction
715 */
716 int j_max_transaction_buffers;
717
718 /*
719 * What is the maximum transaction lifetime before we begin a commit?
720 */
721 unsigned long j_commit_interval;
722
723 /* The timer used to wakeup the commit thread: */
724 struct timer_list j_commit_timer;
725
726 /*
727 * The revoke table: maintains the list of revoked blocks in the
728 * current transaction. [j_revoke_lock]
729 */
730 spinlock_t j_revoke_lock;
731 struct jbd_revoke_table_s *j_revoke;
732 struct jbd_revoke_table_s *j_revoke_table[2];
733
734 /*
735 * array of bhs for journal_commit_transaction
736 */
737 struct buffer_head **j_wbuf;
738 int j_wbufsize;
739
740 /*
741 * this is the pid of the last person to run a synchronous operation
742 * through the journal.
743 */
744 pid_t j_last_sync_writer;
745
746 /*
747 * the average amount of time in nanoseconds it takes to commit a
748 * transaction to the disk. [j_state_lock]
749 */
750 u64 j_average_commit_time;
751
752 /*
753 * An opaque pointer to fs-private information. ext3 puts its
754 * superblock pointer here
755 */
756 void *j_private;
757 };
758
759 /*
760 * Journal flag definitions
761 */
762 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
763 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
764 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
765 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
766 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
767 #define JFS_BARRIER 0x020 /* Use IDE barriers */
768 #define JFS_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
769 * data write error in ordered
770 * mode */
771
772 /*
773 * Function declarations for the journaling transaction and buffer
774 * management
775 */
776
777 /* Filing buffers */
778 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
779 extern void __journal_unfile_buffer(struct journal_head *);
780 extern void __journal_refile_buffer(struct journal_head *);
781 extern void journal_refile_buffer(journal_t *, struct journal_head *);
782 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
783 extern void __journal_free_buffer(struct journal_head *bh);
784 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
785 extern void __journal_clean_data_list(transaction_t *transaction);
786
787 /* Log buffer allocation */
788 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
789 int journal_next_log_block(journal_t *, unsigned int *);
790
791 /* Commit management */
792 extern void journal_commit_transaction(journal_t *);
793
794 /* Checkpoint list management */
795 int __journal_clean_checkpoint_list(journal_t *journal);
796 int __journal_remove_checkpoint(struct journal_head *);
797 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
798
799 /* Buffer IO */
800 extern int
801 journal_write_metadata_buffer(transaction_t *transaction,
802 struct journal_head *jh_in,
803 struct journal_head **jh_out,
804 unsigned int blocknr);
805
806 /* Transaction locking */
807 extern void __wait_on_journal (journal_t *);
808
809 /*
810 * Journal locking.
811 *
812 * We need to lock the journal during transaction state changes so that nobody
813 * ever tries to take a handle on the running transaction while we are in the
814 * middle of moving it to the commit phase. j_state_lock does this.
815 *
816 * Note that the locking is completely interrupt unsafe. We never touch
817 * journal structures from interrupts.
818 */
819
journal_current_handle(void)820 static inline handle_t *journal_current_handle(void)
821 {
822 return current->journal_info;
823 }
824
825 /* The journaling code user interface:
826 *
827 * Create and destroy handles
828 * Register buffer modifications against the current transaction.
829 */
830
831 extern handle_t *journal_start(journal_t *, int nblocks);
832 extern int journal_restart (handle_t *, int nblocks);
833 extern int journal_extend (handle_t *, int nblocks);
834 extern int journal_get_write_access(handle_t *, struct buffer_head *);
835 extern int journal_get_create_access (handle_t *, struct buffer_head *);
836 extern int journal_get_undo_access(handle_t *, struct buffer_head *);
837 extern int journal_dirty_data (handle_t *, struct buffer_head *);
838 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
839 extern void journal_release_buffer (handle_t *, struct buffer_head *);
840 extern int journal_forget (handle_t *, struct buffer_head *);
841 extern void journal_sync_buffer (struct buffer_head *);
842 extern void journal_invalidatepage(journal_t *,
843 struct page *, unsigned long);
844 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
845 extern int journal_stop(handle_t *);
846 extern int journal_flush (journal_t *);
847 extern void journal_lock_updates (journal_t *);
848 extern void journal_unlock_updates (journal_t *);
849
850 extern journal_t * journal_init_dev(struct block_device *bdev,
851 struct block_device *fs_dev,
852 int start, int len, int bsize);
853 extern journal_t * journal_init_inode (struct inode *);
854 extern int journal_update_format (journal_t *);
855 extern int journal_check_used_features
856 (journal_t *, unsigned long, unsigned long, unsigned long);
857 extern int journal_check_available_features
858 (journal_t *, unsigned long, unsigned long, unsigned long);
859 extern int journal_set_features
860 (journal_t *, unsigned long, unsigned long, unsigned long);
861 extern int journal_create (journal_t *);
862 extern int journal_load (journal_t *journal);
863 extern int journal_destroy (journal_t *);
864 extern int journal_recover (journal_t *journal);
865 extern int journal_wipe (journal_t *, int);
866 extern int journal_skip_recovery (journal_t *);
867 extern void journal_update_sb_log_tail (journal_t *, tid_t, unsigned int,
868 int);
869 extern void journal_abort (journal_t *, int);
870 extern int journal_errno (journal_t *);
871 extern void journal_ack_err (journal_t *);
872 extern int journal_clear_err (journal_t *);
873 extern int journal_bmap(journal_t *, unsigned int, unsigned int *);
874 extern int journal_force_commit(journal_t *);
875
876 /*
877 * journal_head management
878 */
879 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
880 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
881 void journal_put_journal_head(struct journal_head *jh);
882
883 /*
884 * handle management
885 */
886 extern struct kmem_cache *jbd_handle_cache;
887
jbd_alloc_handle(gfp_t gfp_flags)888 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
889 {
890 return kmem_cache_zalloc(jbd_handle_cache, gfp_flags);
891 }
892
jbd_free_handle(handle_t * handle)893 static inline void jbd_free_handle(handle_t *handle)
894 {
895 kmem_cache_free(jbd_handle_cache, handle);
896 }
897
898 /* Primary revoke support */
899 #define JOURNAL_REVOKE_DEFAULT_HASH 256
900 extern int journal_init_revoke(journal_t *, int);
901 extern void journal_destroy_revoke_caches(void);
902 extern int journal_init_revoke_caches(void);
903
904 extern void journal_destroy_revoke(journal_t *);
905 extern int journal_revoke (handle_t *,
906 unsigned int, struct buffer_head *);
907 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
908 extern void journal_write_revoke_records(journal_t *,
909 transaction_t *, int);
910
911 /* Recovery revoke support */
912 extern int journal_set_revoke(journal_t *, unsigned int, tid_t);
913 extern int journal_test_revoke(journal_t *, unsigned int, tid_t);
914 extern void journal_clear_revoke(journal_t *);
915 extern void journal_switch_revoke_table(journal_t *journal);
916 extern void journal_clear_buffer_revoked_flags(journal_t *journal);
917
918 /*
919 * The log thread user interface:
920 *
921 * Request space in the current transaction, and force transaction commit
922 * transitions on demand.
923 */
924
925 int __log_space_left(journal_t *); /* Called with journal locked */
926 int log_start_commit(journal_t *journal, tid_t tid);
927 int __log_start_commit(journal_t *journal, tid_t tid);
928 int journal_start_commit(journal_t *journal, tid_t *tid);
929 int journal_force_commit_nested(journal_t *journal);
930 int log_wait_commit(journal_t *journal, tid_t tid);
931 int log_do_checkpoint(journal_t *journal);
932 int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
933
934 void __log_wait_for_space(journal_t *journal);
935 extern void __journal_drop_transaction(journal_t *, transaction_t *);
936 extern int cleanup_journal_tail(journal_t *);
937
938 /* Debugging code only: */
939
940 #define jbd_ENOSYS() \
941 do { \
942 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \
943 current->state = TASK_UNINTERRUPTIBLE; \
944 schedule(); \
945 } while (1)
946
947 /*
948 * is_journal_abort
949 *
950 * Simple test wrapper function to test the JFS_ABORT state flag. This
951 * bit, when set, indicates that we have had a fatal error somewhere,
952 * either inside the journaling layer or indicated to us by the client
953 * (eg. ext3), and that we and should not commit any further
954 * transactions.
955 */
956
is_journal_aborted(journal_t * journal)957 static inline int is_journal_aborted(journal_t *journal)
958 {
959 return journal->j_flags & JFS_ABORT;
960 }
961
is_handle_aborted(handle_t * handle)962 static inline int is_handle_aborted(handle_t *handle)
963 {
964 if (handle->h_aborted)
965 return 1;
966 return is_journal_aborted(handle->h_transaction->t_journal);
967 }
968
journal_abort_handle(handle_t * handle)969 static inline void journal_abort_handle(handle_t *handle)
970 {
971 handle->h_aborted = 1;
972 }
973
974 #endif /* __KERNEL__ */
975
976 /* Comparison functions for transaction IDs: perform comparisons using
977 * modulo arithmetic so that they work over sequence number wraps. */
978
tid_gt(tid_t x,tid_t y)979 static inline int tid_gt(tid_t x, tid_t y)
980 {
981 int difference = (x - y);
982 return (difference > 0);
983 }
984
tid_geq(tid_t x,tid_t y)985 static inline int tid_geq(tid_t x, tid_t y)
986 {
987 int difference = (x - y);
988 return (difference >= 0);
989 }
990
991 extern int journal_blocks_per_page(struct inode *inode);
992
993 /*
994 * Return the minimum number of blocks which must be free in the journal
995 * before a new transaction may be started. Must be called under j_state_lock.
996 */
jbd_space_needed(journal_t * journal)997 static inline int jbd_space_needed(journal_t *journal)
998 {
999 int nblocks = journal->j_max_transaction_buffers;
1000 if (journal->j_committing_transaction)
1001 nblocks += journal->j_committing_transaction->
1002 t_outstanding_credits;
1003 return nblocks;
1004 }
1005
1006 /*
1007 * Definitions which augment the buffer_head layer
1008 */
1009
1010 /* journaling buffer types */
1011 #define BJ_None 0 /* Not journaled */
1012 #define BJ_SyncData 1 /* Normal data: flush before commit */
1013 #define BJ_Metadata 2 /* Normal journaled metadata */
1014 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1015 #define BJ_IO 4 /* Buffer is for temporary IO use */
1016 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1017 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1018 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1019 #define BJ_Locked 8 /* Locked for I/O during commit */
1020 #define BJ_Types 9
1021
1022 extern int jbd_blocks_per_page(struct inode *inode);
1023
1024 #ifdef __KERNEL__
1025
1026 #define buffer_trace_init(bh) do {} while (0)
1027 #define print_buffer_fields(bh) do {} while (0)
1028 #define print_buffer_trace(bh) do {} while (0)
1029 #define BUFFER_TRACE(bh, info) do {} while (0)
1030 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1031 #define JBUFFER_TRACE(jh, info) do {} while (0)
1032
1033 #endif /* __KERNEL__ */
1034
1035 #endif /* _LINUX_JBD_H */
1036