blob: aa56172c6fed9533136aab5f98a43a2912bf19eb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/buffer_head.h>
29#include <linux/journal-head.h>
30#include <linux/stddef.h>
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070031#include <linux/bit_spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <asm/semaphore.h>
33#endif
34
35#define journal_oom_retry 1
36
37/*
38 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
39 * certain classes of error which can occur due to failed IOs. Under
40 * normal use we want ext3 to continue after such errors, because
41 * hardware _can_ fail, but for debugging purposes when running tests on
42 * known-good hardware we may want to trap these errors.
43 */
44#undef JBD_PARANOID_IOFAIL
45
46/*
47 * The default maximum commit age, in seconds.
48 */
49#define JBD_DEFAULT_MAX_COMMIT_AGE 5
50
51#ifdef CONFIG_JBD_DEBUG
52/*
53 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
54 * consistency checks. By default we don't do this unless
55 * CONFIG_JBD_DEBUG is on.
56 */
57#define JBD_EXPENSIVE_CHECKING
58extern int journal_enable_debug;
59
60#define jbd_debug(n, f, a...) \
61 do { \
62 if ((n) <= journal_enable_debug) { \
63 printk (KERN_DEBUG "(%s, %d): %s: ", \
64 __FILE__, __LINE__, __FUNCTION__); \
65 printk (f, ## a); \
66 } \
67 } while (0)
68#else
69#define jbd_debug(f, a...) /**/
70#endif
71
Al Viro27496a82005-10-21 03:20:48 -040072extern void * __jbd_kmalloc (const char *where, size_t size, gfp_t flags, int retry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#define jbd_kmalloc(size, flags) \
74 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
75#define jbd_rep_kmalloc(size, flags) \
76 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
77
78#define JFS_MIN_JOURNAL_BLOCKS 1024
79
80#ifdef __KERNEL__
81
82/**
83 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
84 *
85 * All filesystem modifications made by the process go
86 * through this handle. Recursive operations (such as quota operations)
87 * are gathered into a single update.
88 *
89 * The buffer credits field is used to account for journaled buffers
90 * being modified by the running process. To ensure that there is
91 * enough log space for all outstanding operations, we need to limit the
92 * number of outstanding buffers possible at any time. When the
93 * operation completes, any buffer credits not used are credited back to
94 * the transaction, so that at all times we know how many buffers the
95 * outstanding updates on a transaction might possibly touch.
96 *
97 * This is an opaque datatype.
98 **/
99typedef struct handle_s handle_t; /* Atomic operation type */
100
101
102/**
103 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
104 *
105 * journal_t is linked to from the fs superblock structure.
106 *
107 * We use the journal_t to keep track of all outstanding transaction
108 * activity on the filesystem, and to manage the state of the log
109 * writing process.
110 *
111 * This is an opaque datatype.
112 **/
113typedef struct journal_s journal_t; /* Journal control structure */
114#endif
115
116/*
117 * Internal structures used by the logging mechanism:
118 */
119
120#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
121
122/*
123 * On-disk structures
124 */
125
126/*
127 * Descriptor block types:
128 */
129
130#define JFS_DESCRIPTOR_BLOCK 1
131#define JFS_COMMIT_BLOCK 2
132#define JFS_SUPERBLOCK_V1 3
133#define JFS_SUPERBLOCK_V2 4
134#define JFS_REVOKE_BLOCK 5
135
136/*
137 * Standard header for all descriptor blocks:
138 */
139typedef struct journal_header_s
140{
141 __be32 h_magic;
142 __be32 h_blocktype;
143 __be32 h_sequence;
144} journal_header_t;
145
146
147/*
148 * The block tag: used to describe a single buffer in the journal
149 */
150typedef struct journal_block_tag_s
151{
152 __be32 t_blocknr; /* The on-disk block number */
153 __be32 t_flags; /* See below */
154} journal_block_tag_t;
155
156/*
157 * The revoke descriptor: used on disk to describe a series of blocks to
158 * be revoked from the log
159 */
160typedef struct journal_revoke_header_s
161{
162 journal_header_t r_header;
163 __be32 r_count; /* Count of bytes used in the block */
164} journal_revoke_header_t;
165
166
167/* Definitions for the journal tag flags word: */
168#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
169#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
170#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
171#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
172
173
174/*
175 * The journal superblock. All fields are in big-endian byte order.
176 */
177typedef struct journal_superblock_s
178{
179/* 0x0000 */
180 journal_header_t s_header;
181
182/* 0x000C */
183 /* Static information describing the journal */
184 __be32 s_blocksize; /* journal device blocksize */
185 __be32 s_maxlen; /* total blocks in journal file */
186 __be32 s_first; /* first block of log information */
187
188/* 0x0018 */
189 /* Dynamic information describing the current state of the log */
190 __be32 s_sequence; /* first commit ID expected in log */
191 __be32 s_start; /* blocknr of start of log */
192
193/* 0x0020 */
194 /* Error value, as set by journal_abort(). */
195 __be32 s_errno;
196
197/* 0x0024 */
198 /* Remaining fields are only valid in a version-2 superblock */
199 __be32 s_feature_compat; /* compatible feature set */
200 __be32 s_feature_incompat; /* incompatible feature set */
201 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
202/* 0x0030 */
203 __u8 s_uuid[16]; /* 128-bit uuid for journal */
204
205/* 0x0040 */
206 __be32 s_nr_users; /* Nr of filesystems sharing log */
207
208 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
209
210/* 0x0048 */
211 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
212 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
213
214/* 0x0050 */
215 __u32 s_padding[44];
216
217/* 0x0100 */
218 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
219/* 0x0400 */
220} journal_superblock_t;
221
222#define JFS_HAS_COMPAT_FEATURE(j,mask) \
223 ((j)->j_format_version >= 2 && \
224 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
225#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
226 ((j)->j_format_version >= 2 && \
227 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
228#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
229 ((j)->j_format_version >= 2 && \
230 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
231
232#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
233
234/* Features known to this kernel version: */
235#define JFS_KNOWN_COMPAT_FEATURES 0
236#define JFS_KNOWN_ROCOMPAT_FEATURES 0
237#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
238
239#ifdef __KERNEL__
240
241#include <linux/fs.h>
242#include <linux/sched.h>
243#include <asm/bug.h>
244
245#define JBD_ASSERTIONS
246#ifdef JBD_ASSERTIONS
247#define J_ASSERT(assert) \
248do { \
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)
258void 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) do { } while (0)
273#endif /* JBD_ASSERTIONS */
274
275#if defined(JBD_PARANOID_IOFAIL)
276#define J_EXPECT(expr, why...) J_ASSERT(expr)
277#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
278#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
279#else
280#define __journal_expect(expr, why...) \
281 ({ \
282 int val = (expr); \
283 if (!val) { \
284 printk(KERN_ERR \
285 "EXT3-fs unexpected failure: %s;\n",# expr); \
286 printk(KERN_ERR why "\n"); \
287 } \
288 val; \
289 })
290#define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
291#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
292#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
293#endif
294
295enum jbd_state_bits {
296 BH_JBD /* Has an attached ext3 journal_head */
297 = BH_PrivateStart,
298 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
299 BH_Freed, /* Has been freed (truncated) */
300 BH_Revoked, /* Has been revoked from the log */
301 BH_RevokeValid, /* Revoked flag is valid */
302 BH_JBDDirty, /* Is dirty but journaled */
303 BH_State, /* Pins most journal_head state */
304 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
305 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
306};
307
308BUFFER_FNS(JBD, jbd)
309BUFFER_FNS(JWrite, jwrite)
310BUFFER_FNS(JBDDirty, jbddirty)
311TAS_BUFFER_FNS(JBDDirty, jbddirty)
312BUFFER_FNS(Revoked, revoked)
313TAS_BUFFER_FNS(Revoked, revoked)
314BUFFER_FNS(RevokeValid, revokevalid)
315TAS_BUFFER_FNS(RevokeValid, revokevalid)
316BUFFER_FNS(Freed, freed)
317
318static inline struct buffer_head *jh2bh(struct journal_head *jh)
319{
320 return jh->b_bh;
321}
322
323static inline struct journal_head *bh2jh(struct buffer_head *bh)
324{
325 return bh->b_private;
326}
327
328static inline void jbd_lock_bh_state(struct buffer_head *bh)
329{
330 bit_spin_lock(BH_State, &bh->b_state);
331}
332
333static inline int jbd_trylock_bh_state(struct buffer_head *bh)
334{
335 return bit_spin_trylock(BH_State, &bh->b_state);
336}
337
338static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
339{
340 return bit_spin_is_locked(BH_State, &bh->b_state);
341}
342
343static inline void jbd_unlock_bh_state(struct buffer_head *bh)
344{
345 bit_spin_unlock(BH_State, &bh->b_state);
346}
347
348static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
349{
350 bit_spin_lock(BH_JournalHead, &bh->b_state);
351}
352
353static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
354{
355 bit_spin_unlock(BH_JournalHead, &bh->b_state);
356}
357
358struct jbd_revoke_table_s;
359
360/**
361 * struct handle_s - The handle_s type is the concrete type associated with
362 * handle_t.
363 * @h_transaction: Which compound transaction is this update a part of?
364 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
365 * @h_ref: Reference count on this handle
366 * @h_err: Field for caller's use to track errors through large fs operations
367 * @h_sync: flag for sync-on-close
368 * @h_jdata: flag to force data journaling
369 * @h_aborted: flag indicating fatal error on handle
370 **/
371
372/* Docbook can't yet cope with the bit fields, but will leave the documentation
373 * in so it can be fixed later.
374 */
375
376struct handle_s
377{
378 /* Which compound transaction is this update a part of? */
379 transaction_t *h_transaction;
380
381 /* Number of remaining buffers we are allowed to dirty: */
382 int h_buffer_credits;
383
384 /* Reference count on this handle */
385 int h_ref;
386
387 /* Field for caller's use to track errors through large fs */
388 /* operations */
389 int h_err;
390
391 /* Flags [no locking] */
392 unsigned int h_sync: 1; /* sync-on-close */
393 unsigned int h_jdata: 1; /* force data journaling */
394 unsigned int h_aborted: 1; /* fatal error on handle */
395};
396
397
398/* The transaction_t type is the guts of the journaling mechanism. It
399 * tracks a compound transaction through its various states:
400 *
401 * RUNNING: accepting new updates
402 * LOCKED: Updates still running but we don't accept new ones
403 * RUNDOWN: Updates are tidying up but have finished requesting
404 * new buffers to modify (state not used for now)
405 * FLUSH: All updates complete, but we are still writing to disk
406 * COMMIT: All data on disk, writing commit record
407 * FINISHED: We still have to keep the transaction for checkpointing.
408 *
409 * The transaction keeps track of all of the buffers modified by a
410 * running transaction, and all of the buffers committed but not yet
411 * flushed to home for finished transactions.
412 */
413
414/*
415 * Lock ranking:
416 *
417 * j_list_lock
418 * ->jbd_lock_bh_journal_head() (This is "innermost")
419 *
420 * j_state_lock
421 * ->jbd_lock_bh_state()
422 *
423 * jbd_lock_bh_state()
424 * ->j_list_lock
425 *
426 * j_state_lock
427 * ->t_handle_lock
428 *
429 * j_state_lock
430 * ->j_list_lock (journal_unmap_buffer)
431 *
432 */
433
434struct transaction_s
435{
436 /* Pointer to the journal for this transaction. [no locking] */
437 journal_t *t_journal;
438
439 /* Sequence number for this transaction [no locking] */
440 tid_t t_tid;
441
442 /*
443 * Transaction's current state
444 * [no locking - only kjournald alters this]
445 * FIXME: needs barriers
446 * KLUDGE: [use j_state_lock]
447 */
448 enum {
449 T_RUNNING,
450 T_LOCKED,
451 T_RUNDOWN,
452 T_FLUSH,
453 T_COMMIT,
454 T_FINISHED
455 } t_state;
456
457 /*
458 * Where in the log does this transaction's commit start? [no locking]
459 */
460 unsigned long t_log_start;
461
462 /* Number of buffers on the t_buffers list [j_list_lock] */
463 int t_nr_buffers;
464
465 /*
466 * Doubly-linked circular list of all buffers reserved but not yet
467 * modified by this transaction [j_list_lock]
468 */
469 struct journal_head *t_reserved_list;
470
471 /*
472 * Doubly-linked circular list of all buffers under writeout during
473 * commit [j_list_lock]
474 */
475 struct journal_head *t_locked_list;
476
477 /*
478 * Doubly-linked circular list of all metadata buffers owned by this
479 * transaction [j_list_lock]
480 */
481 struct journal_head *t_buffers;
482
483 /*
484 * Doubly-linked circular list of all data buffers still to be
485 * flushed before this transaction can be committed [j_list_lock]
486 */
487 struct journal_head *t_sync_datalist;
488
489 /*
490 * Doubly-linked circular list of all forget buffers (superseded
491 * buffers which we can un-checkpoint once this transaction commits)
492 * [j_list_lock]
493 */
494 struct journal_head *t_forget;
495
496 /*
497 * Doubly-linked circular list of all buffers still to be flushed before
498 * this transaction can be checkpointed. [j_list_lock]
499 */
500 struct journal_head *t_checkpoint_list;
501
502 /*
503 * Doubly-linked circular list of temporary buffers currently undergoing
504 * IO in the log [j_list_lock]
505 */
506 struct journal_head *t_iobuf_list;
507
508 /*
509 * Doubly-linked circular list of metadata buffers being shadowed by log
510 * IO. The IO buffers on the iobuf list and the shadow buffers on this
511 * list match each other one for one at all times. [j_list_lock]
512 */
513 struct journal_head *t_shadow_list;
514
515 /*
516 * Doubly-linked circular list of control buffers being written to the
517 * log. [j_list_lock]
518 */
519 struct journal_head *t_log_list;
520
521 /*
522 * Protects info related to handles
523 */
524 spinlock_t t_handle_lock;
525
526 /*
527 * Number of outstanding updates running on this transaction
528 * [t_handle_lock]
529 */
530 int t_updates;
531
532 /*
533 * Number of buffers reserved for use by all handles in this transaction
534 * handle but not yet modified. [t_handle_lock]
535 */
536 int t_outstanding_credits;
537
538 /*
539 * Forward and backward links for the circular list of all transactions
540 * awaiting checkpoint. [j_list_lock]
541 */
542 transaction_t *t_cpnext, *t_cpprev;
543
544 /*
545 * When will the transaction expire (become due for commit), in jiffies?
546 * [no locking]
547 */
548 unsigned long t_expires;
549
550 /*
551 * How many handles used this transaction? [t_handle_lock]
552 */
553 int t_handle_count;
554
555};
556
557/**
558 * struct journal_s - The journal_s type is the concrete type associated with
559 * journal_t.
560 * @j_flags: General journaling state flags
561 * @j_errno: Is there an outstanding uncleared error on the journal (from a
562 * prior abort)?
563 * @j_sb_buffer: First part of superblock buffer
564 * @j_superblock: Second part of superblock buffer
565 * @j_format_version: Version of the superblock format
566 * @j_state_lock: Protect the various scalars in the journal
567 * @j_barrier_count: Number of processes waiting to create a barrier lock
568 * @j_barrier: The barrier lock itself
569 * @j_running_transaction: The current running transaction..
570 * @j_committing_transaction: the transaction we are pushing to disk
571 * @j_checkpoint_transactions: a linked circular list of all transactions
572 * waiting for checkpointing
573 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
574 * to start committing, or for a barrier lock to be released
575 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
576 * @j_wait_done_commit: Wait queue for waiting for commit to complete
577 * @j_wait_checkpoint: Wait queue to trigger checkpointing
578 * @j_wait_commit: Wait queue to trigger commit
579 * @j_wait_updates: Wait queue to wait for updates to complete
580 * @j_checkpoint_sem: Semaphore for locking against concurrent checkpoints
581 * @j_head: Journal head - identifies the first unused block in the journal
582 * @j_tail: Journal tail - identifies the oldest still-used block in the
583 * journal.
584 * @j_free: Journal free - how many free blocks are there in the journal?
585 * @j_first: The block number of the first usable block
586 * @j_last: The block number one beyond the last usable block
587 * @j_dev: Device where we store the journal
588 * @j_blocksize: blocksize for the location where we store the journal.
589 * @j_blk_offset: starting block offset for into the device where we store the
590 * journal
591 * @j_fs_dev: Device which holds the client fs. For internal journal this will
592 * be equal to j_dev
593 * @j_maxlen: Total maximum capacity of the journal region on disk.
594 * @j_list_lock: Protects the buffer lists and internal buffer state.
595 * @j_inode: Optional inode where we store the journal. If present, all journal
596 * block numbers are mapped into this inode via bmap().
597 * @j_tail_sequence: Sequence number of the oldest transaction in the log
598 * @j_transaction_sequence: Sequence number of the next transaction to grant
599 * @j_commit_sequence: Sequence number of the most recently committed
600 * transaction
601 * @j_commit_request: Sequence number of the most recent transaction wanting
602 * commit
603 * @j_uuid: Uuid of client object.
604 * @j_task: Pointer to the current commit thread for this journal
605 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
606 * single compound commit transaction
607 * @j_commit_interval: What is the maximum transaction lifetime before we begin
608 * a commit?
609 * @j_commit_timer: The timer used to wakeup the commit thread
610 * @j_revoke_lock: Protect the revoke table
611 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
612 * current transaction.
613 * @j_revoke_table: alternate revoke tables for j_revoke
Randy Dunlap6c8bec62005-11-07 01:01:04 -0800614 * @j_wbuf: array of buffer_heads for journal_commit_transaction
615 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
616 * number that will fit in j_blocksize
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 * @j_private: An opaque pointer to fs-private information.
618 */
619
620struct journal_s
621{
622 /* General journaling state flags [j_state_lock] */
623 unsigned long j_flags;
624
625 /*
626 * Is there an outstanding uncleared error on the journal (from a prior
627 * abort)? [j_state_lock]
628 */
629 int j_errno;
630
631 /* The superblock buffer */
632 struct buffer_head *j_sb_buffer;
633 journal_superblock_t *j_superblock;
634
635 /* Version of the superblock format */
636 int j_format_version;
637
638 /*
639 * Protect the various scalars in the journal
640 */
641 spinlock_t j_state_lock;
642
643 /*
644 * Number of processes waiting to create a barrier lock [j_state_lock]
645 */
646 int j_barrier_count;
647
648 /* The barrier lock itself */
649 struct semaphore j_barrier;
650
651 /*
652 * Transactions: The current running transaction...
653 * [j_state_lock] [caller holding open handle]
654 */
655 transaction_t *j_running_transaction;
656
657 /*
658 * the transaction we are pushing to disk
659 * [j_state_lock] [caller holding open handle]
660 */
661 transaction_t *j_committing_transaction;
662
663 /*
664 * ... and a linked circular list of all transactions waiting for
665 * checkpointing. [j_list_lock]
666 */
667 transaction_t *j_checkpoint_transactions;
668
669 /*
670 * Wait queue for waiting for a locked transaction to start committing,
671 * or for a barrier lock to be released
672 */
673 wait_queue_head_t j_wait_transaction_locked;
674
675 /* Wait queue for waiting for checkpointing to complete */
676 wait_queue_head_t j_wait_logspace;
677
678 /* Wait queue for waiting for commit to complete */
679 wait_queue_head_t j_wait_done_commit;
680
681 /* Wait queue to trigger checkpointing */
682 wait_queue_head_t j_wait_checkpoint;
683
684 /* Wait queue to trigger commit */
685 wait_queue_head_t j_wait_commit;
686
687 /* Wait queue to wait for updates to complete */
688 wait_queue_head_t j_wait_updates;
689
690 /* Semaphore for locking against concurrent checkpoints */
691 struct semaphore j_checkpoint_sem;
692
693 /*
694 * Journal head: identifies the first unused block in the journal.
695 * [j_state_lock]
696 */
697 unsigned long j_head;
698
699 /*
700 * Journal tail: identifies the oldest still-used block in the journal.
701 * [j_state_lock]
702 */
703 unsigned long j_tail;
704
705 /*
706 * Journal free: how many free blocks are there in the journal?
707 * [j_state_lock]
708 */
709 unsigned long j_free;
710
711 /*
712 * Journal start and end: the block numbers of the first usable block
713 * and one beyond the last usable block in the journal. [j_state_lock]
714 */
715 unsigned long j_first;
716 unsigned long j_last;
717
718 /*
719 * Device, blocksize and starting block offset for the location where we
720 * store the journal.
721 */
722 struct block_device *j_dev;
723 int j_blocksize;
724 unsigned int j_blk_offset;
725
726 /*
727 * Device which holds the client fs. For internal journal this will be
728 * equal to j_dev.
729 */
730 struct block_device *j_fs_dev;
731
732 /* Total maximum capacity of the journal region on disk. */
733 unsigned int j_maxlen;
734
735 /*
736 * Protects the buffer lists and internal buffer state.
737 */
738 spinlock_t j_list_lock;
739
740 /* Optional inode where we store the journal. If present, all */
741 /* journal block numbers are mapped into this inode via */
742 /* bmap(). */
743 struct inode *j_inode;
744
745 /*
746 * Sequence number of the oldest transaction in the log [j_state_lock]
747 */
748 tid_t j_tail_sequence;
749
750 /*
751 * Sequence number of the next transaction to grant [j_state_lock]
752 */
753 tid_t j_transaction_sequence;
754
755 /*
756 * Sequence number of the most recently committed transaction
757 * [j_state_lock].
758 */
759 tid_t j_commit_sequence;
760
761 /*
762 * Sequence number of the most recent transaction wanting commit
763 * [j_state_lock]
764 */
765 tid_t j_commit_request;
766
767 /*
768 * Journal uuid: identifies the object (filesystem, LVM volume etc)
769 * backed by this journal. This will eventually be replaced by an array
770 * of uuids, allowing us to index multiple devices within a single
771 * journal and to perform atomic updates across them.
772 */
773 __u8 j_uuid[16];
774
775 /* Pointer to the current commit thread for this journal */
776 struct task_struct *j_task;
777
778 /*
779 * Maximum number of metadata buffers to allow in a single compound
780 * commit transaction
781 */
782 int j_max_transaction_buffers;
783
784 /*
785 * What is the maximum transaction lifetime before we begin a commit?
786 */
787 unsigned long j_commit_interval;
788
789 /* The timer used to wakeup the commit thread: */
790 struct timer_list *j_commit_timer;
791
792 /*
793 * The revoke table: maintains the list of revoked blocks in the
794 * current transaction. [j_revoke_lock]
795 */
796 spinlock_t j_revoke_lock;
797 struct jbd_revoke_table_s *j_revoke;
798 struct jbd_revoke_table_s *j_revoke_table[2];
799
800 /*
801 * array of bhs for journal_commit_transaction
802 */
803 struct buffer_head **j_wbuf;
804 int j_wbufsize;
805
806 /*
807 * An opaque pointer to fs-private information. ext3 puts its
808 * superblock pointer here
809 */
810 void *j_private;
811};
812
813/*
814 * Journal flag definitions
815 */
816#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
817#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
818#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
819#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
820#define JFS_LOADED 0x010 /* The journal superblock has been loaded */
821#define JFS_BARRIER 0x020 /* Use IDE barriers */
822
823/*
824 * Function declarations for the journaling transaction and buffer
825 * management
826 */
827
828/* Filing buffers */
829extern void __journal_temp_unlink_buffer(struct journal_head *jh);
830extern void journal_unfile_buffer(journal_t *, struct journal_head *);
831extern void __journal_unfile_buffer(struct journal_head *);
832extern void __journal_refile_buffer(struct journal_head *);
833extern void journal_refile_buffer(journal_t *, struct journal_head *);
834extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
835extern void __journal_free_buffer(struct journal_head *bh);
836extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
837extern void __journal_clean_data_list(transaction_t *transaction);
838
839/* Log buffer allocation */
840extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
841int journal_next_log_block(journal_t *, unsigned long *);
842
843/* Commit management */
844extern void journal_commit_transaction(journal_t *);
845
846/* Checkpoint list management */
847int __journal_clean_checkpoint_list(journal_t *journal);
848void __journal_remove_checkpoint(struct journal_head *);
849void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
850
851/* Buffer IO */
852extern int
853journal_write_metadata_buffer(transaction_t *transaction,
854 struct journal_head *jh_in,
855 struct journal_head **jh_out,
856 int blocknr);
857
858/* Transaction locking */
859extern void __wait_on_journal (journal_t *);
860
861/*
862 * Journal locking.
863 *
864 * We need to lock the journal during transaction state changes so that nobody
865 * ever tries to take a handle on the running transaction while we are in the
866 * middle of moving it to the commit phase. j_state_lock does this.
867 *
868 * Note that the locking is completely interrupt unsafe. We never touch
869 * journal structures from interrupts.
870 */
871
872static inline handle_t *journal_current_handle(void)
873{
874 return current->journal_info;
875}
876
877/* The journaling code user interface:
878 *
879 * Create and destroy handles
880 * Register buffer modifications against the current transaction.
881 */
882
883extern handle_t *journal_start(journal_t *, int nblocks);
884extern int journal_restart (handle_t *, int nblocks);
885extern int journal_extend (handle_t *, int nblocks);
886extern int journal_get_write_access(handle_t *, struct buffer_head *);
887extern int journal_get_create_access (handle_t *, struct buffer_head *);
888extern int journal_get_undo_access(handle_t *, struct buffer_head *);
889extern int journal_dirty_data (handle_t *, struct buffer_head *);
890extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
891extern void journal_release_buffer (handle_t *, struct buffer_head *);
892extern int journal_forget (handle_t *, struct buffer_head *);
893extern void journal_sync_buffer (struct buffer_head *);
894extern int journal_invalidatepage(journal_t *,
895 struct page *, unsigned long);
Al Viro27496a82005-10-21 03:20:48 -0400896extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897extern int journal_stop(handle_t *);
898extern int journal_flush (journal_t *);
899extern void journal_lock_updates (journal_t *);
900extern void journal_unlock_updates (journal_t *);
901
902extern journal_t * journal_init_dev(struct block_device *bdev,
903 struct block_device *fs_dev,
904 int start, int len, int bsize);
905extern journal_t * journal_init_inode (struct inode *);
906extern int journal_update_format (journal_t *);
907extern int journal_check_used_features
908 (journal_t *, unsigned long, unsigned long, unsigned long);
909extern int journal_check_available_features
910 (journal_t *, unsigned long, unsigned long, unsigned long);
911extern int journal_set_features
912 (journal_t *, unsigned long, unsigned long, unsigned long);
913extern int journal_create (journal_t *);
914extern int journal_load (journal_t *journal);
915extern void journal_destroy (journal_t *);
916extern int journal_recover (journal_t *journal);
917extern int journal_wipe (journal_t *, int);
918extern int journal_skip_recovery (journal_t *);
919extern void journal_update_superblock (journal_t *, int);
920extern void __journal_abort_hard (journal_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921extern void journal_abort (journal_t *, int);
922extern int journal_errno (journal_t *);
923extern void journal_ack_err (journal_t *);
924extern int journal_clear_err (journal_t *);
925extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
926extern int journal_force_commit(journal_t *);
927
928/*
929 * journal_head management
930 */
931struct journal_head *journal_add_journal_head(struct buffer_head *bh);
932struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
933void journal_remove_journal_head(struct buffer_head *bh);
934void journal_put_journal_head(struct journal_head *jh);
935
936/*
937 * handle management
938 */
939extern kmem_cache_t *jbd_handle_cache;
940
Al Virodd0fc662005-10-07 07:46:04 +0100941static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942{
943 return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
944}
945
946static inline void jbd_free_handle(handle_t *handle)
947{
948 kmem_cache_free(jbd_handle_cache, handle);
949}
950
951/* Primary revoke support */
952#define JOURNAL_REVOKE_DEFAULT_HASH 256
953extern int journal_init_revoke(journal_t *, int);
954extern void journal_destroy_revoke_caches(void);
955extern int journal_init_revoke_caches(void);
956
957extern void journal_destroy_revoke(journal_t *);
958extern int journal_revoke (handle_t *,
959 unsigned long, struct buffer_head *);
960extern int journal_cancel_revoke(handle_t *, struct journal_head *);
961extern void journal_write_revoke_records(journal_t *, transaction_t *);
962
963/* Recovery revoke support */
964extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
965extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
966extern void journal_clear_revoke(journal_t *);
967extern void journal_brelse_array(struct buffer_head *b[], int n);
968extern void journal_switch_revoke_table(journal_t *journal);
969
970/*
971 * The log thread user interface:
972 *
973 * Request space in the current transaction, and force transaction commit
974 * transitions on demand.
975 */
976
977int __log_space_left(journal_t *); /* Called with journal locked */
978int log_start_commit(journal_t *journal, tid_t tid);
979int __log_start_commit(journal_t *journal, tid_t tid);
980int journal_start_commit(journal_t *journal, tid_t *tid);
981int journal_force_commit_nested(journal_t *journal);
982int log_wait_commit(journal_t *journal, tid_t tid);
983int log_do_checkpoint(journal_t *journal);
984
985void __log_wait_for_space(journal_t *journal);
986extern void __journal_drop_transaction(journal_t *, transaction_t *);
987extern int cleanup_journal_tail(journal_t *);
988
989/* Debugging code only: */
990
991#define jbd_ENOSYS() \
992do { \
993 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
994 current->state = TASK_UNINTERRUPTIBLE; \
995 schedule(); \
996} while (1)
997
998/*
999 * is_journal_abort
1000 *
1001 * Simple test wrapper function to test the JFS_ABORT state flag. This
1002 * bit, when set, indicates that we have had a fatal error somewhere,
1003 * either inside the journaling layer or indicated to us by the client
1004 * (eg. ext3), and that we and should not commit any further
1005 * transactions.
1006 */
1007
1008static inline int is_journal_aborted(journal_t *journal)
1009{
1010 return journal->j_flags & JFS_ABORT;
1011}
1012
1013static inline int is_handle_aborted(handle_t *handle)
1014{
1015 if (handle->h_aborted)
1016 return 1;
1017 return is_journal_aborted(handle->h_transaction->t_journal);
1018}
1019
1020static inline void journal_abort_handle(handle_t *handle)
1021{
1022 handle->h_aborted = 1;
1023}
1024
1025#endif /* __KERNEL__ */
1026
1027/* Comparison functions for transaction IDs: perform comparisons using
1028 * modulo arithmetic so that they work over sequence number wraps. */
1029
1030static inline int tid_gt(tid_t x, tid_t y)
1031{
1032 int difference = (x - y);
1033 return (difference > 0);
1034}
1035
1036static inline int tid_geq(tid_t x, tid_t y)
1037{
1038 int difference = (x - y);
1039 return (difference >= 0);
1040}
1041
1042extern int journal_blocks_per_page(struct inode *inode);
1043
1044/*
1045 * Return the minimum number of blocks which must be free in the journal
1046 * before a new transaction may be started. Must be called under j_state_lock.
1047 */
1048static inline int jbd_space_needed(journal_t *journal)
1049{
1050 int nblocks = journal->j_max_transaction_buffers;
1051 if (journal->j_committing_transaction)
1052 nblocks += journal->j_committing_transaction->
1053 t_outstanding_credits;
1054 return nblocks;
1055}
1056
1057/*
1058 * Definitions which augment the buffer_head layer
1059 */
1060
1061/* journaling buffer types */
1062#define BJ_None 0 /* Not journaled */
1063#define BJ_SyncData 1 /* Normal data: flush before commit */
1064#define BJ_Metadata 2 /* Normal journaled metadata */
1065#define BJ_Forget 3 /* Buffer superseded by this transaction */
1066#define BJ_IO 4 /* Buffer is for temporary IO use */
1067#define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1068#define BJ_LogCtl 6 /* Buffer contains log descriptors */
1069#define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1070#define BJ_Locked 8 /* Locked for I/O during commit */
1071#define BJ_Types 9
1072
1073extern int jbd_blocks_per_page(struct inode *inode);
1074
1075#ifdef __KERNEL__
1076
1077#define buffer_trace_init(bh) do {} while (0)
1078#define print_buffer_fields(bh) do {} while (0)
1079#define print_buffer_trace(bh) do {} while (0)
1080#define BUFFER_TRACE(bh, info) do {} while (0)
1081#define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1082#define JBUFFER_TRACE(jh, info) do {} while (0)
1083
1084#endif /* __KERNEL__ */
1085
1086#endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
1087
1088/*
1089 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
1090 * go here.
1091 */
1092
1093#if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
1094
1095#define J_ASSERT(expr) do {} while (0)
1096#define J_ASSERT_BH(bh, expr) do {} while (0)
1097#define buffer_jbd(bh) 0
1098#define journal_buffer_journal_lru(bh) 0
1099
1100#endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
1101#endif /* _LINUX_JBD_H */