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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * linux/include/linux/jbd2.h
4 *
5 * Written by Stephen C. Tweedie <sct@redhat.com>
6 *
7 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
8 *
9 * Definitions for transaction data structures for the buffer cache
10 * filesystem journaling support.
11 */
12
13#ifndef _LINUX_JBD2_H
14#define _LINUX_JBD2_H
15
16/* Allow this file to be included directly into e2fsprogs */
17#ifndef __KERNEL__
18#include "jfs_compat.h"
19#define JBD2_DEBUG
20#else
21
22#include <linux/types.h>
23#include <linux/buffer_head.h>
24#include <linux/journal-head.h>
25#include <linux/stddef.h>
26#include <linux/mutex.h>
27#include <linux/timer.h>
28#include <linux/slab.h>
29#include <linux/bit_spinlock.h>
30#include <linux/blkdev.h>
31#include <linux/crc32c.h>
32#endif
33
34#define journal_oom_retry 1
35
36/*
37 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
38 * certain classes of error which can occur due to failed IOs. Under
39 * normal use we want ext4 to continue after such errors, because
40 * hardware _can_ fail, but for debugging purposes when running tests on
41 * known-good hardware we may want to trap these errors.
42 */
43#undef JBD2_PARANOID_IOFAIL
44
45/*
46 * The default maximum commit age, in seconds.
47 */
48#define JBD2_DEFAULT_MAX_COMMIT_AGE 5
49
50#ifdef CONFIG_JBD2_DEBUG
51/*
52 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
53 * consistency checks. By default we don't do this unless
54 * CONFIG_JBD2_DEBUG is on.
55 */
56#define JBD2_EXPENSIVE_CHECKING
57void __jbd2_debug(int level, const char *file, const char *func,
58 unsigned int line, const char *fmt, ...);
59
60#define jbd2_debug(n, fmt, a...) \
61 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
62#else
63#define jbd2_debug(n, fmt, a...) no_printk(fmt, ##a)
64#endif
65
66extern void *jbd2_alloc(size_t size, gfp_t flags);
67extern void jbd2_free(void *ptr, size_t size);
68
69#define JBD2_MIN_JOURNAL_BLOCKS 1024
70#define JBD2_DEFAULT_FAST_COMMIT_BLOCKS 256
71
72#ifdef __KERNEL__
73
74/**
75 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
76 *
77 * All filesystem modifications made by the process go
78 * through this handle. Recursive operations (such as quota operations)
79 * are gathered into a single update.
80 *
81 * The buffer credits field is used to account for journaled buffers
82 * being modified by the running process. To ensure that there is
83 * enough log space for all outstanding operations, we need to limit the
84 * number of outstanding buffers possible at any time. When the
85 * operation completes, any buffer credits not used are credited back to
86 * the transaction, so that at all times we know how many buffers the
87 * outstanding updates on a transaction might possibly touch.
88 *
89 * This is an opaque datatype.
90 **/
91typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */
92
93
94/**
95 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
96 *
97 * journal_t is linked to from the fs superblock structure.
98 *
99 * We use the journal_t to keep track of all outstanding transaction
100 * activity on the filesystem, and to manage the state of the log
101 * writing process.
102 *
103 * This is an opaque datatype.
104 **/
105typedef struct journal_s journal_t; /* Journal control structure */
106#endif
107
108/*
109 * Internal structures used by the logging mechanism:
110 */
111
112#define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
113
114/*
115 * On-disk structures
116 */
117
118/*
119 * Descriptor block types:
120 */
121
122#define JBD2_DESCRIPTOR_BLOCK 1
123#define JBD2_COMMIT_BLOCK 2
124#define JBD2_SUPERBLOCK_V1 3
125#define JBD2_SUPERBLOCK_V2 4
126#define JBD2_REVOKE_BLOCK 5
127
128/*
129 * Standard header for all descriptor blocks:
130 */
131typedef struct journal_header_s
132{
133 __be32 h_magic;
134 __be32 h_blocktype;
135 __be32 h_sequence;
136} journal_header_t;
137
138/*
139 * Checksum types.
140 */
141#define JBD2_CRC32_CHKSUM 1
142#define JBD2_MD5_CHKSUM 2
143#define JBD2_SHA1_CHKSUM 3
144#define JBD2_CRC32C_CHKSUM 4
145
146#define JBD2_CRC32_CHKSUM_SIZE 4
147
148#define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
149/*
150 * Commit block header for storing transactional checksums:
151 *
152 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
153 * fields are used to store a checksum of the descriptor and data blocks.
154 *
155 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
156 * field is used to store crc32c(uuid+commit_block). Each journal metadata
157 * block gets its own checksum, and data block checksums are stored in
158 * journal_block_tag (in the descriptor). The other h_chksum* fields are
159 * not used.
160 *
161 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
162 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
163 * is the same as v2.
164 *
165 * Checksum v1, v2, and v3 are mutually exclusive features.
166 */
167struct commit_header {
168 __be32 h_magic;
169 __be32 h_blocktype;
170 __be32 h_sequence;
171 unsigned char h_chksum_type;
172 unsigned char h_chksum_size;
173 unsigned char h_padding[2];
174 __be32 h_chksum[JBD2_CHECKSUM_BYTES];
175 __be64 h_commit_sec;
176 __be32 h_commit_nsec;
177};
178
179/*
180 * The block tag: used to describe a single buffer in the journal.
181 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
182 * raw struct shouldn't be used for pointer math or sizeof() - use
183 * journal_tag_bytes(journal) instead to compute this.
184 */
185typedef struct journal_block_tag3_s
186{
187 __be32 t_blocknr; /* The on-disk block number */
188 __be32 t_flags; /* See below */
189 __be32 t_blocknr_high; /* most-significant high 32bits. */
190 __be32 t_checksum; /* crc32c(uuid+seq+block) */
191} journal_block_tag3_t;
192
193typedef struct journal_block_tag_s
194{
195 __be32 t_blocknr; /* The on-disk block number */
196 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */
197 __be16 t_flags; /* See below */
198 __be32 t_blocknr_high; /* most-significant high 32bits. */
199} journal_block_tag_t;
200
201/* Tail of descriptor or revoke block, for checksumming */
202struct jbd2_journal_block_tail {
203 __be32 t_checksum; /* crc32c(uuid+descr_block) */
204};
205
206/*
207 * The revoke descriptor: used on disk to describe a series of blocks to
208 * be revoked from the log
209 */
210typedef struct jbd2_journal_revoke_header_s
211{
212 journal_header_t r_header;
213 __be32 r_count; /* Count of bytes used in the block */
214} jbd2_journal_revoke_header_t;
215
216/* Definitions for the journal tag flags word: */
217#define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */
218#define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */
219#define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */
220#define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
221
222
223/*
224 * The journal superblock. All fields are in big-endian byte order.
225 */
226typedef struct journal_superblock_s
227{
228/* 0x0000 */
229 journal_header_t s_header;
230
231/* 0x000C */
232 /* Static information describing the journal */
233 __be32 s_blocksize; /* journal device blocksize */
234 __be32 s_maxlen; /* total blocks in journal file */
235 __be32 s_first; /* first block of log information */
236
237/* 0x0018 */
238 /* Dynamic information describing the current state of the log */
239 __be32 s_sequence; /* first commit ID expected in log */
240 __be32 s_start; /* blocknr of start of log */
241
242/* 0x0020 */
243 /* Error value, as set by jbd2_journal_abort(). */
244 __be32 s_errno;
245
246/* 0x0024 */
247 /* Remaining fields are only valid in a version-2 superblock */
248 __be32 s_feature_compat; /* compatible feature set */
249 __be32 s_feature_incompat; /* incompatible feature set */
250 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
251/* 0x0030 */
252 __u8 s_uuid[16]; /* 128-bit uuid for journal */
253
254/* 0x0040 */
255 __be32 s_nr_users; /* Nr of filesystems sharing log */
256
257 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
258
259/* 0x0048 */
260 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
261 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
262
263/* 0x0050 */
264 __u8 s_checksum_type; /* checksum type */
265 __u8 s_padding2[3];
266/* 0x0054 */
267 __be32 s_num_fc_blks; /* Number of fast commit blocks */
268 __be32 s_head; /* blocknr of head of log, only uptodate
269 * while the filesystem is clean */
270/* 0x005C */
271 __u32 s_padding[40];
272 __be32 s_checksum; /* crc32c(superblock) */
273
274/* 0x0100 */
275 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
276/* 0x0400 */
277} journal_superblock_t;
278
279#define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001
280
281#define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001
282#define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002
283#define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
284#define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008
285#define JBD2_FEATURE_INCOMPAT_CSUM_V3 0x00000010
286#define JBD2_FEATURE_INCOMPAT_FAST_COMMIT 0x00000020
287
288/* See "journal feature predicate functions" below */
289
290/* Features known to this kernel version: */
291#define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM
292#define JBD2_KNOWN_ROCOMPAT_FEATURES 0
293#define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \
294 JBD2_FEATURE_INCOMPAT_64BIT | \
295 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
296 JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
297 JBD2_FEATURE_INCOMPAT_CSUM_V3 | \
298 JBD2_FEATURE_INCOMPAT_FAST_COMMIT)
299
300#ifdef __KERNEL__
301
302#include <linux/fs.h>
303#include <linux/sched.h>
304
305enum jbd_state_bits {
306 BH_JBD /* Has an attached ext3 journal_head */
307 = BH_PrivateStart,
308 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
309 BH_Freed, /* Has been freed (truncated) */
310 BH_Revoked, /* Has been revoked from the log */
311 BH_RevokeValid, /* Revoked flag is valid */
312 BH_JBDDirty, /* Is dirty but journaled */
313 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
314 BH_Shadow, /* IO on shadow buffer is running */
315 BH_Verified, /* Metadata block has been verified ok */
316 BH_JBDPrivateStart, /* First bit available for private use by FS */
317};
318
319BUFFER_FNS(JBD, jbd)
320BUFFER_FNS(JWrite, jwrite)
321BUFFER_FNS(JBDDirty, jbddirty)
322TAS_BUFFER_FNS(JBDDirty, jbddirty)
323BUFFER_FNS(Revoked, revoked)
324TAS_BUFFER_FNS(Revoked, revoked)
325BUFFER_FNS(RevokeValid, revokevalid)
326TAS_BUFFER_FNS(RevokeValid, revokevalid)
327BUFFER_FNS(Freed, freed)
328BUFFER_FNS(Shadow, shadow)
329BUFFER_FNS(Verified, verified)
330
331static inline struct buffer_head *jh2bh(struct journal_head *jh)
332{
333 return jh->b_bh;
334}
335
336static inline struct journal_head *bh2jh(struct buffer_head *bh)
337{
338 return bh->b_private;
339}
340
341static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
342{
343 bit_spin_lock(BH_JournalHead, &bh->b_state);
344}
345
346static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
347{
348 bit_spin_unlock(BH_JournalHead, &bh->b_state);
349}
350
351#define J_ASSERT(assert) BUG_ON(!(assert))
352
353#define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
354#define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
355
356#if defined(JBD2_PARANOID_IOFAIL)
357#define J_EXPECT(expr, why...) J_ASSERT(expr)
358#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
359#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
360#else
361#define __journal_expect(expr, why...) \
362 ({ \
363 int val = (expr); \
364 if (!val) { \
365 printk(KERN_ERR \
366 "JBD2 unexpected failure: %s: %s;\n", \
367 __func__, #expr); \
368 printk(KERN_ERR why "\n"); \
369 } \
370 val; \
371 })
372#define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
373#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
374#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
375#endif
376
377/* Flags in jbd_inode->i_flags */
378#define __JI_COMMIT_RUNNING 0
379#define __JI_WRITE_DATA 1
380#define __JI_WAIT_DATA 2
381
382/*
383 * Commit of the inode data in progress. We use this flag to protect us from
384 * concurrent deletion of inode. We cannot use reference to inode for this
385 * since we cannot afford doing last iput() on behalf of kjournald
386 */
387#define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
388/* Write allocated dirty buffers in this inode before commit */
389#define JI_WRITE_DATA (1 << __JI_WRITE_DATA)
390/* Wait for outstanding data writes for this inode before commit */
391#define JI_WAIT_DATA (1 << __JI_WAIT_DATA)
392
393/**
394 * struct jbd2_inode - The jbd_inode type is the structure linking inodes in
395 * ordered mode present in a transaction so that we can sync them during commit.
396 */
397struct jbd2_inode {
398 /**
399 * @i_transaction:
400 *
401 * Which transaction does this inode belong to? Either the running
402 * transaction or the committing one. [j_list_lock]
403 */
404 transaction_t *i_transaction;
405
406 /**
407 * @i_next_transaction:
408 *
409 * Pointer to the running transaction modifying inode's data in case
410 * there is already a committing transaction touching it. [j_list_lock]
411 */
412 transaction_t *i_next_transaction;
413
414 /**
415 * @i_list: List of inodes in the i_transaction [j_list_lock]
416 */
417 struct list_head i_list;
418
419 /**
420 * @i_vfs_inode:
421 *
422 * VFS inode this inode belongs to [constant for lifetime of structure]
423 */
424 struct inode *i_vfs_inode;
425
426 /**
427 * @i_flags: Flags of inode [j_list_lock]
428 */
429 unsigned long i_flags;
430
431 /**
432 * @i_dirty_start_page:
433 *
434 * Dirty range start in PAGE_SIZE units.
435 *
436 * The dirty range is empty if @i_dirty_start_page is greater than or
437 * equal to @i_dirty_end_page.
438 *
439 * [j_list_lock]
440 */
441 pgoff_t i_dirty_start_page;
442
443 /**
444 * @i_dirty_end_page:
445 *
446 * Dirty range end in PAGE_SIZE units (exclusive).
447 *
448 * [j_list_lock]
449 */
450 pgoff_t i_dirty_end_page;
451};
452
453/*
454 * Lockless readers treat start_page >= end_page as an empty range.
455 * Writers publish a new non-empty range by storing i_dirty_end_page before
456 * i_dirty_start_page.
457 */
458static inline bool jbd2_jinode_get_dirty_range(const struct jbd2_inode *jinode,
459 loff_t *start, loff_t *end)
460{
461 pgoff_t start_page = READ_ONCE(jinode->i_dirty_start_page);
462 pgoff_t end_page = READ_ONCE(jinode->i_dirty_end_page);
463
464 if (start_page >= end_page)
465 return false;
466
467 *start = (loff_t)start_page << PAGE_SHIFT;
468 *end = ((loff_t)end_page << PAGE_SHIFT) - 1;
469 return true;
470}
471
472struct jbd2_revoke_table_s;
473
474/**
475 * struct jbd2_journal_handle - The jbd2_journal_handle type is the concrete
476 * type associated with handle_t.
477 * @h_transaction: Which compound transaction is this update a part of?
478 * @h_journal: Which journal handle belongs to - used iff h_reserved set.
479 * @h_rsv_handle: Handle reserved for finishing the logical operation.
480 * @h_total_credits: Number of remaining buffers we are allowed to add to
481 * journal. These are dirty buffers and revoke descriptor blocks.
482 * @h_revoke_credits: Number of remaining revoke records available for handle
483 * @h_ref: Reference count on this handle.
484 * @h_err: Field for caller's use to track errors through large fs operations.
485 * @h_sync: Flag for sync-on-close.
486 * @h_reserved: Flag for handle for reserved credits.
487 * @h_aborted: Flag indicating fatal error on handle.
488 * @h_type: For handle statistics.
489 * @h_line_no: For handle statistics.
490 * @h_start_jiffies: Handle Start time.
491 * @h_requested_credits: Holds @h_total_credits after handle is started.
492 * @h_revoke_credits_requested: Holds @h_revoke_credits after handle is started.
493 * @saved_alloc_context: Saved context while transaction is open.
494 **/
495
496/* Docbook can't yet cope with the bit fields, but will leave the documentation
497 * in so it can be fixed later.
498 */
499
500struct jbd2_journal_handle
501{
502 union {
503 transaction_t *h_transaction;
504 /* Which journal handle belongs to - used iff h_reserved set */
505 journal_t *h_journal;
506 };
507
508 handle_t *h_rsv_handle;
509 int h_total_credits;
510 int h_revoke_credits;
511 int h_revoke_credits_requested;
512 int h_ref;
513 int h_err;
514
515 /* Flags [no locking] */
516 unsigned int h_sync: 1;
517 unsigned int h_reserved: 1;
518 unsigned int h_aborted: 1;
519 unsigned int h_type: 8;
520 unsigned int h_line_no: 16;
521
522 unsigned long h_start_jiffies;
523 unsigned int h_requested_credits;
524
525 unsigned int saved_alloc_context;
526};
527
528
529/*
530 * Some stats for checkpoint phase
531 */
532struct transaction_chp_stats_s {
533 unsigned long cs_chp_time;
534 __u32 cs_forced_to_close;
535 __u32 cs_written;
536 __u32 cs_dropped;
537};
538
539/* The transaction_t type is the guts of the journaling mechanism. It
540 * tracks a compound transaction through its various states:
541 *
542 * RUNNING: accepting new updates
543 * LOCKED: Updates still running but we don't accept new ones
544 * RUNDOWN: Updates are tidying up but have finished requesting
545 * new buffers to modify (state not used for now)
546 * FLUSH: All updates complete, but we are still writing to disk
547 * COMMIT: All data on disk, writing commit record
548 * FINISHED: We still have to keep the transaction for checkpointing.
549 *
550 * The transaction keeps track of all of the buffers modified by a
551 * running transaction, and all of the buffers committed but not yet
552 * flushed to home for finished transactions.
553 * (Locking Documentation improved by LockDoc)
554 */
555
556/*
557 * Lock ranking:
558 *
559 * j_list_lock
560 * ->jbd_lock_bh_journal_head() (This is "innermost")
561 *
562 * j_state_lock
563 * ->b_state_lock
564 *
565 * b_state_lock
566 * ->j_list_lock
567 *
568 * j_state_lock
569 * ->j_list_lock (journal_unmap_buffer)
570 *
571 */
572
573struct transaction_s
574{
575 /* Pointer to the journal for this transaction. [no locking] */
576 journal_t *t_journal;
577
578 /* Sequence number for this transaction [no locking] */
579 tid_t t_tid;
580
581 /*
582 * Transaction's current state
583 * [no locking - only kjournald2 alters this]
584 * [j_list_lock] guards transition of a transaction into T_FINISHED
585 * state and subsequent call of __jbd2_journal_drop_transaction()
586 * FIXME: needs barriers
587 * KLUDGE: [use j_state_lock]
588 */
589 enum {
590 T_RUNNING,
591 T_LOCKED,
592 T_SWITCH,
593 T_FLUSH,
594 T_COMMIT,
595 T_COMMIT_DFLUSH,
596 T_COMMIT_JFLUSH,
597 T_COMMIT_CALLBACK,
598 T_FINISHED
599 } t_state;
600
601 /*
602 * Where in the log does this transaction's commit start? [no locking]
603 */
604 unsigned long t_log_start;
605
606 /*
607 * Number of buffers on the t_buffers list [j_list_lock, no locks
608 * needed for jbd2 thread]
609 */
610 int t_nr_buffers;
611
612 /*
613 * Doubly-linked circular list of all buffers reserved but not yet
614 * modified by this transaction [j_list_lock, no locks needed fo
615 * jbd2 thread]
616 */
617 struct journal_head *t_reserved_list;
618
619 /*
620 * Doubly-linked circular list of all metadata buffers owned by this
621 * transaction [j_list_lock, no locks needed for jbd2 thread]
622 */
623 struct journal_head *t_buffers;
624
625 /*
626 * Doubly-linked circular list of all forget buffers (superseded
627 * buffers which we can un-checkpoint once this transaction commits)
628 * [j_list_lock]
629 */
630 struct journal_head *t_forget;
631
632 /*
633 * Doubly-linked circular list of all buffers still to be flushed before
634 * this transaction can be checkpointed. [j_list_lock]
635 */
636 struct journal_head *t_checkpoint_list;
637
638 /*
639 * Doubly-linked circular list of metadata buffers being
640 * shadowed by log IO. The IO buffers on the iobuf list and
641 * the shadow buffers on this list match each other one for
642 * one at all times. [j_list_lock, no locks needed for jbd2
643 * thread]
644 */
645 struct journal_head *t_shadow_list;
646
647 /*
648 * List of inodes associated with the transaction; e.g., ext4 uses
649 * this to track inodes in data=ordered and data=journal mode that
650 * need special handling on transaction commit; also used by ocfs2.
651 * [j_list_lock]
652 */
653 struct list_head t_inode_list;
654
655 /*
656 * Longest time some handle had to wait for running transaction
657 */
658 unsigned long t_max_wait;
659
660 /*
661 * When transaction started
662 */
663 unsigned long t_start;
664
665 /*
666 * When commit was requested [j_state_lock]
667 */
668 unsigned long t_requested;
669
670 /*
671 * Checkpointing stats [j_list_lock]
672 */
673 struct transaction_chp_stats_s t_chp_stats;
674
675 /*
676 * Number of outstanding updates running on this transaction
677 * [none]
678 */
679 atomic_t t_updates;
680
681 /*
682 * Number of blocks reserved for this transaction in the journal.
683 * This is including all credits reserved when starting transaction
684 * handles as well as all journal descriptor blocks needed for this
685 * transaction. [none]
686 */
687 atomic_t t_outstanding_credits;
688
689 /*
690 * Number of revoke records for this transaction added by already
691 * stopped handles. [none]
692 */
693 atomic_t t_outstanding_revokes;
694
695 /*
696 * How many handles used this transaction? [none]
697 */
698 atomic_t t_handle_count;
699
700 /*
701 * Forward and backward links for the circular list of all transactions
702 * awaiting checkpoint. [j_list_lock]
703 */
704 transaction_t *t_cpnext, *t_cpprev;
705
706 /*
707 * When will the transaction expire (become due for commit), in jiffies?
708 * [no locking]
709 */
710 unsigned long t_expires;
711
712 /*
713 * When this transaction started, in nanoseconds [no locking]
714 */
715 ktime_t t_start_time;
716
717 /*
718 * This transaction is being forced and some process is
719 * waiting for it to finish.
720 */
721 unsigned int t_synchronous_commit:1;
722
723 /* Disk flush needs to be sent to fs partition [no locking] */
724 int t_need_data_flush;
725};
726
727struct transaction_run_stats_s {
728 unsigned long rs_wait;
729 unsigned long rs_request_delay;
730 unsigned long rs_running;
731 unsigned long rs_locked;
732 unsigned long rs_flushing;
733 unsigned long rs_logging;
734
735 __u32 rs_handle_count;
736 __u32 rs_blocks;
737 __u32 rs_blocks_logged;
738};
739
740struct transaction_stats_s {
741 unsigned long ts_tid;
742 unsigned long ts_requested;
743 struct transaction_run_stats_s run;
744};
745
746static inline unsigned long
747jbd2_time_diff(unsigned long start, unsigned long end)
748{
749 if (end >= start)
750 return end - start;
751
752 return end + (MAX_JIFFY_OFFSET - start);
753}
754
755#define JBD2_NR_BATCH 64
756
757enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
758
759#define JBD2_FC_REPLAY_STOP 0
760#define JBD2_FC_REPLAY_CONTINUE 1
761
762/**
763 * struct journal_s - The journal_s type is the concrete type associated with
764 * journal_t.
765 */
766struct journal_s
767{
768 /**
769 * @j_flags: General journaling state flags [j_state_lock,
770 * no lock for quick racy checks]
771 */
772 unsigned long j_flags;
773
774 /**
775 * @j_errno:
776 *
777 * Is there an outstanding uncleared error on the journal (from a prior
778 * abort)? [j_state_lock]
779 */
780 int j_errno;
781
782 /**
783 * @j_abort_mutex: Lock the whole aborting procedure.
784 */
785 struct mutex j_abort_mutex;
786
787 /**
788 * @j_sb_buffer: The first part of the superblock buffer.
789 */
790 struct buffer_head *j_sb_buffer;
791
792 /**
793 * @j_superblock: The second part of the superblock buffer.
794 */
795 journal_superblock_t *j_superblock;
796
797 /**
798 * @j_state_lock: Protect the various scalars in the journal.
799 */
800 rwlock_t j_state_lock;
801
802 /**
803 * @j_barrier_count:
804 *
805 * Number of processes waiting to create a barrier lock [j_state_lock,
806 * no lock for quick racy checks]
807 */
808 int j_barrier_count;
809
810 /**
811 * @j_barrier: The barrier lock itself.
812 */
813 struct mutex j_barrier;
814
815 /**
816 * @j_running_transaction:
817 *
818 * Transactions: The current running transaction...
819 * [j_state_lock, no lock for quick racy checks] [caller holding
820 * open handle]
821 */
822 transaction_t *j_running_transaction;
823
824 /**
825 * @j_committing_transaction:
826 *
827 * the transaction we are pushing to disk
828 * [j_state_lock] [caller holding open handle]
829 */
830 transaction_t *j_committing_transaction;
831
832 /**
833 * @j_checkpoint_transactions:
834 *
835 * ... and a linked circular list of all transactions waiting for
836 * checkpointing. [j_list_lock]
837 */
838 transaction_t *j_checkpoint_transactions;
839
840 /**
841 * @j_wait_transaction_locked:
842 *
843 * Wait queue for waiting for a locked transaction to start committing,
844 * or for a barrier lock to be released.
845 */
846 wait_queue_head_t j_wait_transaction_locked;
847
848 /**
849 * @j_wait_done_commit: Wait queue for waiting for commit to complete.
850 */
851 wait_queue_head_t j_wait_done_commit;
852
853 /**
854 * @j_wait_commit: Wait queue to trigger commit.
855 */
856 wait_queue_head_t j_wait_commit;
857
858 /**
859 * @j_wait_updates: Wait queue to wait for updates to complete.
860 */
861 wait_queue_head_t j_wait_updates;
862
863 /**
864 * @j_wait_reserved:
865 *
866 * Wait queue to wait for reserved buffer credits to drop.
867 */
868 wait_queue_head_t j_wait_reserved;
869
870 /**
871 * @j_fc_wait:
872 *
873 * Wait queue to wait for completion of async fast commits.
874 */
875 wait_queue_head_t j_fc_wait;
876
877 /**
878 * @j_checkpoint_mutex:
879 *
880 * Semaphore for locking against concurrent checkpoints.
881 */
882 struct mutex j_checkpoint_mutex;
883
884 /**
885 * @j_chkpt_bhs:
886 *
887 * List of buffer heads used by the checkpoint routine. This
888 * was moved from jbd2_log_do_checkpoint() to reduce stack
889 * usage. Access to this array is controlled by the
890 * @j_checkpoint_mutex. [j_checkpoint_mutex]
891 */
892 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
893
894 /**
895 * @j_shrinker:
896 *
897 * Journal head shrinker, reclaim buffer's journal head which
898 * has been written back.
899 */
900 struct shrinker *j_shrinker;
901
902 /**
903 * @j_checkpoint_jh_count:
904 *
905 * Number of journal buffers on the checkpoint list. [j_list_lock]
906 */
907 struct percpu_counter j_checkpoint_jh_count;
908
909 /**
910 * @j_shrink_transaction:
911 *
912 * Record next transaction will shrink on the checkpoint list.
913 * [j_list_lock]
914 */
915 transaction_t *j_shrink_transaction;
916
917 /**
918 * @j_head:
919 *
920 * Journal head: identifies the first unused block in the journal.
921 * [j_state_lock]
922 */
923 unsigned long j_head;
924
925 /**
926 * @j_tail:
927 *
928 * Journal tail: identifies the oldest still-used block in the journal.
929 * [j_state_lock]
930 */
931 unsigned long j_tail;
932
933 /**
934 * @j_free:
935 *
936 * Journal free: how many free blocks are there in the journal?
937 * [j_state_lock]
938 */
939 unsigned long j_free;
940
941 /**
942 * @j_first:
943 *
944 * The block number of the first usable block in the journal
945 * [j_state_lock].
946 */
947 unsigned long j_first;
948
949 /**
950 * @j_last:
951 *
952 * The block number one beyond the last usable block in the journal
953 * [j_state_lock].
954 */
955 unsigned long j_last;
956
957 /**
958 * @j_fc_first:
959 *
960 * The block number of the first fast commit block in the journal
961 * [j_state_lock].
962 */
963 unsigned long j_fc_first;
964
965 /**
966 * @j_fc_off:
967 *
968 * Number of fast commit blocks currently allocated. Accessed only
969 * during fast commit. Currently only process can do fast commit, so
970 * this field is not protected by any lock.
971 */
972 unsigned long j_fc_off;
973
974 /**
975 * @j_fc_last:
976 *
977 * The block number one beyond the last fast commit block in the journal
978 * [j_state_lock].
979 */
980 unsigned long j_fc_last;
981
982 /**
983 * @j_dev: Device where we store the journal.
984 */
985 struct block_device *j_dev;
986
987 /**
988 * @j_blocksize: Block size for the location where we store the journal.
989 */
990 int j_blocksize;
991
992 /**
993 * @j_blk_offset:
994 *
995 * Starting block offset into the device where we store the journal.
996 */
997 unsigned long long j_blk_offset;
998
999 /**
1000 * @j_devname: Journal device name.
1001 */
1002 char j_devname[BDEVNAME_SIZE+24];
1003
1004 /**
1005 * @j_fs_dev:
1006 *
1007 * Device which holds the client fs. For internal journal this will be
1008 * equal to j_dev.
1009 */
1010 struct block_device *j_fs_dev;
1011
1012 /**
1013 * @j_fs_dev_wb_err:
1014 *
1015 * Records the errseq of the client fs's backing block device.
1016 */
1017 errseq_t j_fs_dev_wb_err;
1018
1019 /**
1020 * @j_total_len: Total maximum capacity of the journal region on disk.
1021 */
1022 unsigned int j_total_len;
1023
1024 /**
1025 * @j_reserved_credits:
1026 *
1027 * Number of buffers reserved from the running transaction.
1028 */
1029 atomic_t j_reserved_credits;
1030
1031 /**
1032 * @j_list_lock: Protects the buffer lists and internal buffer state.
1033 */
1034 spinlock_t j_list_lock;
1035
1036 /**
1037 * @j_inode:
1038 *
1039 * Optional inode where we store the journal. If present, all
1040 * journal block numbers are mapped into this inode via bmap().
1041 */
1042 struct inode *j_inode;
1043
1044 /**
1045 * @j_tail_sequence:
1046 *
1047 * Sequence number of the oldest transaction in the log [j_state_lock]
1048 */
1049 tid_t j_tail_sequence;
1050
1051 /**
1052 * @j_transaction_sequence:
1053 *
1054 * Sequence number of the next transaction to grant [j_state_lock]
1055 */
1056 tid_t j_transaction_sequence;
1057
1058 /**
1059 * @j_commit_sequence:
1060 *
1061 * Sequence number of the most recently committed transaction
1062 * [j_state_lock, no lock for quick racy checks]
1063 */
1064 tid_t j_commit_sequence;
1065
1066 /**
1067 * @j_commit_request:
1068 *
1069 * Sequence number of the most recent transaction wanting commit
1070 * [j_state_lock, no lock for quick racy checks]
1071 */
1072 tid_t j_commit_request;
1073
1074 /**
1075 * @j_uuid:
1076 *
1077 * Journal uuid: identifies the object (filesystem, LVM volume etc)
1078 * backed by this journal. This will eventually be replaced by an array
1079 * of uuids, allowing us to index multiple devices within a single
1080 * journal and to perform atomic updates across them.
1081 */
1082 __u8 j_uuid[16];
1083
1084 /**
1085 * @j_task: Pointer to the current commit thread for this journal.
1086 */
1087 struct task_struct *j_task;
1088
1089 /**
1090 * @j_max_transaction_buffers:
1091 *
1092 * Maximum number of metadata buffers to allow in a single compound
1093 * commit transaction.
1094 */
1095 int j_max_transaction_buffers;
1096
1097 /**
1098 * @j_revoke_records_per_block:
1099 *
1100 * Number of revoke records that fit in one descriptor block.
1101 */
1102 int j_revoke_records_per_block;
1103
1104 /**
1105 * @j_transaction_overhead_buffers:
1106 *
1107 * Number of blocks each transaction needs for its own bookkeeping
1108 */
1109 int j_transaction_overhead_buffers;
1110
1111 /**
1112 * @j_commit_interval:
1113 *
1114 * What is the maximum transaction lifetime before we begin a commit?
1115 */
1116 unsigned long j_commit_interval;
1117
1118 /**
1119 * @j_commit_timer: The timer used to wakeup the commit thread.
1120 */
1121 struct timer_list j_commit_timer;
1122
1123 /**
1124 * @j_revoke_lock: Protect the revoke table.
1125 */
1126 spinlock_t j_revoke_lock;
1127
1128 /**
1129 * @j_revoke:
1130 *
1131 * The revoke table - maintains the list of revoked blocks in the
1132 * current transaction.
1133 */
1134 struct jbd2_revoke_table_s *j_revoke;
1135
1136 /**
1137 * @j_revoke_table: Alternate revoke tables for j_revoke.
1138 */
1139 struct jbd2_revoke_table_s *j_revoke_table[2];
1140
1141 /**
1142 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
1143 */
1144 struct buffer_head **j_wbuf;
1145
1146 /**
1147 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
1148 * during a fast commit. Currently only process can do fast commit, so
1149 * this field is not protected by any lock.
1150 */
1151 struct buffer_head **j_fc_wbuf;
1152
1153 /**
1154 * @j_wbufsize:
1155 *
1156 * Size of @j_wbuf array.
1157 */
1158 int j_wbufsize;
1159
1160 /**
1161 * @j_fc_wbufsize:
1162 *
1163 * Size of @j_fc_wbuf array.
1164 */
1165 int j_fc_wbufsize;
1166
1167 /**
1168 * @j_last_sync_writer:
1169 *
1170 * The pid of the last person to run a synchronous operation
1171 * through the journal.
1172 */
1173 pid_t j_last_sync_writer;
1174
1175 /**
1176 * @j_average_commit_time:
1177 *
1178 * The average amount of time in nanoseconds it takes to commit a
1179 * transaction to disk. [j_state_lock]
1180 */
1181 u64 j_average_commit_time;
1182
1183 /**
1184 * @j_min_batch_time:
1185 *
1186 * Minimum time that we should wait for additional filesystem operations
1187 * to get batched into a synchronous handle in microseconds.
1188 */
1189 u32 j_min_batch_time;
1190
1191 /**
1192 * @j_max_batch_time:
1193 *
1194 * Maximum time that we should wait for additional filesystem operations
1195 * to get batched into a synchronous handle in microseconds.
1196 */
1197 u32 j_max_batch_time;
1198
1199 /**
1200 * @j_commit_callback:
1201 *
1202 * This function is called when a transaction is closed.
1203 */
1204 void (*j_commit_callback)(journal_t *,
1205 transaction_t *);
1206
1207 /**
1208 * @j_submit_inode_data_buffers:
1209 *
1210 * This function is called for all inodes associated with the
1211 * committing transaction marked with JI_WRITE_DATA flag
1212 * before we start to write out the transaction to the journal.
1213 */
1214 int (*j_submit_inode_data_buffers)
1215 (struct jbd2_inode *);
1216
1217 /**
1218 * @j_finish_inode_data_buffers:
1219 *
1220 * This function is called for all inodes associated with the
1221 * committing transaction marked with JI_WAIT_DATA flag
1222 * after we have written the transaction to the journal
1223 * but before we write out the commit block.
1224 */
1225 int (*j_finish_inode_data_buffers)
1226 (struct jbd2_inode *);
1227
1228 /*
1229 * Journal statistics
1230 */
1231
1232 /**
1233 * @j_history_lock: Protect the transactions statistics history.
1234 */
1235 spinlock_t j_history_lock;
1236
1237 /**
1238 * @j_proc_entry: procfs entry for the jbd statistics directory.
1239 */
1240 struct proc_dir_entry *j_proc_entry;
1241
1242 /**
1243 * @j_stats: Overall statistics.
1244 */
1245 struct transaction_stats_s j_stats;
1246
1247 /**
1248 * @j_failed_commit: Failed journal commit ID.
1249 */
1250 unsigned int j_failed_commit;
1251
1252 /**
1253 * @j_private:
1254 *
1255 * An opaque pointer to fs-private information. ext3 puts its
1256 * superblock pointer here.
1257 */
1258 void *j_private;
1259
1260 /**
1261 * @j_csum_seed:
1262 *
1263 * Precomputed journal UUID checksum for seeding other checksums.
1264 */
1265 __u32 j_csum_seed;
1266
1267#ifdef CONFIG_DEBUG_LOCK_ALLOC
1268 /**
1269 * @j_trans_commit_map:
1270 *
1271 * Lockdep entity to track transaction commit dependencies. Handles
1272 * hold this "lock" for read, when we wait for commit, we acquire the
1273 * "lock" for writing. This matches the properties of jbd2 journalling
1274 * where the running transaction has to wait for all handles to be
1275 * dropped to commit that transaction and also acquiring a handle may
1276 * require transaction commit to finish.
1277 */
1278 struct lockdep_map j_trans_commit_map;
1279#endif
1280 /**
1281 * @jbd2_trans_commit_key:
1282 *
1283 * "struct lock_class_key" for @j_trans_commit_map
1284 */
1285 struct lock_class_key jbd2_trans_commit_key;
1286
1287 /**
1288 * @j_fc_cleanup_callback:
1289 *
1290 * Clean-up after fast commit or full commit. JBD2 calls this function
1291 * after every commit operation.
1292 */
1293 void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
1294
1295 /**
1296 * @j_fc_replay_callback:
1297 *
1298 * File-system specific function that performs replay of a fast
1299 * commit. JBD2 calls this function for each fast commit block found in
1300 * the journal. This function should return JBD2_FC_REPLAY_CONTINUE
1301 * to indicate that the block was processed correctly and more fast
1302 * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP
1303 * indicates the end of replay (no more blocks remaining). A negative
1304 * return value indicates error.
1305 */
1306 int (*j_fc_replay_callback)(struct journal_s *journal,
1307 struct buffer_head *bh,
1308 enum passtype pass, int off,
1309 tid_t expected_commit_id);
1310
1311 /**
1312 * @j_bmap:
1313 *
1314 * Bmap function that should be used instead of the generic
1315 * VFS bmap function.
1316 */
1317 int (*j_bmap)(struct journal_s *journal, sector_t *block);
1318};
1319
1320#define jbd2_might_wait_for_commit(j) \
1321 do { \
1322 rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
1323 rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
1324 } while (0)
1325
1326/*
1327 * We can support any known requested features iff the
1328 * superblock is not in version 1. Otherwise we fail to support any
1329 * extended sb features.
1330 */
1331static inline bool jbd2_format_support_feature(journal_t *j)
1332{
1333 return j->j_superblock->s_header.h_blocktype !=
1334 cpu_to_be32(JBD2_SUPERBLOCK_V1);
1335}
1336
1337/* journal feature predicate functions */
1338#define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1339static inline bool jbd2_has_feature_##name(journal_t *j) \
1340{ \
1341 return (jbd2_format_support_feature(j) && \
1342 ((j)->j_superblock->s_feature_compat & \
1343 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1344} \
1345static inline void jbd2_set_feature_##name(journal_t *j) \
1346{ \
1347 (j)->j_superblock->s_feature_compat |= \
1348 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1349} \
1350static inline void jbd2_clear_feature_##name(journal_t *j) \
1351{ \
1352 (j)->j_superblock->s_feature_compat &= \
1353 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1354}
1355
1356#define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1357static inline bool jbd2_has_feature_##name(journal_t *j) \
1358{ \
1359 return (jbd2_format_support_feature(j) && \
1360 ((j)->j_superblock->s_feature_ro_compat & \
1361 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1362} \
1363static inline void jbd2_set_feature_##name(journal_t *j) \
1364{ \
1365 (j)->j_superblock->s_feature_ro_compat |= \
1366 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1367} \
1368static inline void jbd2_clear_feature_##name(journal_t *j) \
1369{ \
1370 (j)->j_superblock->s_feature_ro_compat &= \
1371 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1372}
1373
1374#define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1375static inline bool jbd2_has_feature_##name(journal_t *j) \
1376{ \
1377 return (jbd2_format_support_feature(j) && \
1378 ((j)->j_superblock->s_feature_incompat & \
1379 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1380} \
1381static inline void jbd2_set_feature_##name(journal_t *j) \
1382{ \
1383 (j)->j_superblock->s_feature_incompat |= \
1384 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1385} \
1386static inline void jbd2_clear_feature_##name(journal_t *j) \
1387{ \
1388 (j)->j_superblock->s_feature_incompat &= \
1389 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1390}
1391
1392JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
1393
1394JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
1395JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
1396JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
1397JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
1398JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
1399JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT)
1400
1401/* Journal high priority write IO operation flags */
1402#define JBD2_JOURNAL_REQ_FLAGS (REQ_META | REQ_SYNC | REQ_IDLE)
1403
1404/*
1405 * Journal flag definitions
1406 */
1407#define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1408#define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1409#define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1410#define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1411#define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1412#define JBD2_BARRIER 0x020 /* Use IDE barriers */
1413#define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on
1414 * clean and empty filesystem
1415 * logging area */
1416#define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */
1417#define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
1418#define JBD2_JOURNAL_FLUSH_DISCARD 0x0001
1419#define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002
1420#define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \
1421 JBD2_JOURNAL_FLUSH_ZEROOUT)
1422
1423/*
1424 * Function declarations for the journaling transaction and buffer
1425 * management
1426 */
1427
1428/* Filing buffers */
1429extern bool __jbd2_journal_refile_buffer(struct journal_head *);
1430extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1431extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1432extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1433static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1434{
1435 list_add_tail(&bh->b_assoc_buffers, head);
1436}
1437static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1438{
1439 list_del_init(&bh->b_assoc_buffers);
1440}
1441
1442/* Log buffer allocation */
1443struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
1444void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
1445int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1446int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1447 unsigned long *block);
1448int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1449void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1450
1451/* Commit management */
1452extern void jbd2_journal_commit_transaction(journal_t *);
1453
1454/* Checkpoint list management */
1455enum jbd2_shrink_type {JBD2_SHRINK_DESTROY, JBD2_SHRINK_BUSY_STOP, JBD2_SHRINK_BUSY_SKIP};
1456
1457void __jbd2_journal_clean_checkpoint_list(journal_t *journal, enum jbd2_shrink_type type);
1458unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
1459int __jbd2_journal_remove_checkpoint(struct journal_head *);
1460int jbd2_journal_try_remove_checkpoint(struct journal_head *jh);
1461void jbd2_journal_destroy_checkpoint(journal_t *journal);
1462void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1463
1464
1465/*
1466 * Triggers
1467 */
1468
1469struct jbd2_buffer_trigger_type {
1470 /*
1471 * Fired a the moment data to write to the journal are known to be
1472 * stable - so either at the moment b_frozen_data is created or just
1473 * before a buffer is written to the journal. mapped_data is a mapped
1474 * buffer that is the frozen data for commit.
1475 */
1476 void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1477 struct buffer_head *bh, void *mapped_data,
1478 size_t size);
1479
1480 /*
1481 * Fired during journal abort for dirty buffers that will not be
1482 * committed.
1483 */
1484 void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1485 struct buffer_head *bh);
1486};
1487
1488extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1489 void *mapped_data,
1490 struct jbd2_buffer_trigger_type *triggers);
1491extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1492 struct jbd2_buffer_trigger_type *triggers);
1493
1494/* Buffer IO */
1495extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1496 struct journal_head *jh_in,
1497 struct buffer_head **bh_out,
1498 sector_t blocknr);
1499
1500/* Transaction cache support */
1501extern void jbd2_journal_destroy_transaction_cache(void);
1502extern int __init jbd2_journal_init_transaction_cache(void);
1503extern void jbd2_journal_free_transaction(transaction_t *);
1504
1505/*
1506 * Journal locking.
1507 *
1508 * We need to lock the journal during transaction state changes so that nobody
1509 * ever tries to take a handle on the running transaction while we are in the
1510 * middle of moving it to the commit phase. j_state_lock does this.
1511 *
1512 * Note that the locking is completely interrupt unsafe. We never touch
1513 * journal structures from interrupts.
1514 */
1515
1516static inline handle_t *journal_current_handle(void)
1517{
1518 return current->journal_info;
1519}
1520
1521/* The journaling code user interface:
1522 *
1523 * Create and destroy handles
1524 * Register buffer modifications against the current transaction.
1525 */
1526
1527extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1528extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1529 int revoke_records, gfp_t gfp_mask,
1530 unsigned int type, unsigned int line_no);
1531extern int jbd2_journal_restart(handle_t *, int nblocks);
1532extern int jbd2__journal_restart(handle_t *, int nblocks,
1533 int revoke_records, gfp_t gfp_mask);
1534extern int jbd2_journal_start_reserved(handle_t *handle,
1535 unsigned int type, unsigned int line_no);
1536extern void jbd2_journal_free_reserved(handle_t *handle);
1537extern int jbd2_journal_extend(handle_t *handle, int nblocks,
1538 int revoke_records);
1539extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1540extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1541extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1542void jbd2_journal_set_triggers(struct buffer_head *,
1543 struct jbd2_buffer_trigger_type *type);
1544extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1545extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1546int jbd2_journal_invalidate_folio(journal_t *, struct folio *,
1547 size_t offset, size_t length);
1548bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio);
1549extern int jbd2_journal_stop(handle_t *);
1550extern int jbd2_journal_flush(journal_t *journal, unsigned int flags);
1551extern void jbd2_journal_lock_updates (journal_t *);
1552extern void jbd2_journal_unlock_updates (journal_t *);
1553
1554void jbd2_journal_wait_updates(journal_t *);
1555
1556extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1557 struct block_device *fs_dev,
1558 unsigned long long start, int len, int bsize);
1559extern journal_t * jbd2_journal_init_inode (struct inode *);
1560extern int jbd2_journal_update_format (journal_t *);
1561extern int jbd2_journal_check_used_features
1562 (journal_t *, unsigned long, unsigned long, unsigned long);
1563extern int jbd2_journal_check_available_features
1564 (journal_t *, unsigned long, unsigned long, unsigned long);
1565extern int jbd2_journal_set_features
1566 (journal_t *, unsigned long, unsigned long, unsigned long);
1567extern void jbd2_journal_clear_features
1568 (journal_t *, unsigned long, unsigned long, unsigned long);
1569extern int jbd2_journal_load (journal_t *journal);
1570extern int jbd2_journal_destroy (journal_t *);
1571extern int jbd2_journal_recover (journal_t *journal);
1572extern int jbd2_journal_wipe (journal_t *, int);
1573extern int jbd2_journal_skip_recovery (journal_t *);
1574extern void jbd2_journal_update_sb_errno(journal_t *);
1575extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t,
1576 unsigned long, blk_opf_t);
1577extern void jbd2_journal_abort (journal_t *, int);
1578extern int jbd2_journal_errno (journal_t *);
1579extern void jbd2_journal_ack_err (journal_t *);
1580extern int jbd2_journal_clear_err (journal_t *);
1581extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1582extern int jbd2_journal_force_commit(journal_t *);
1583extern int jbd2_journal_force_commit_nested(journal_t *);
1584extern int jbd2_journal_inode_ranged_write(handle_t *handle,
1585 struct jbd2_inode *inode, loff_t start_byte,
1586 loff_t length);
1587extern int jbd2_journal_inode_ranged_wait(handle_t *handle,
1588 struct jbd2_inode *inode, loff_t start_byte,
1589 loff_t length);
1590extern int jbd2_journal_finish_inode_data_buffers(
1591 struct jbd2_inode *jinode);
1592extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
1593 struct jbd2_inode *inode, loff_t new_size);
1594extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1595extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1596
1597/*
1598 * journal_head management
1599 */
1600struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1601struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1602void jbd2_journal_put_journal_head(struct journal_head *jh);
1603
1604/*
1605 * handle management
1606 */
1607extern struct kmem_cache *jbd2_handle_cache;
1608
1609/*
1610 * This specialized allocator has to be a macro for its allocations to be
1611 * accounted separately (to have a separate alloc_tag). The typecast is
1612 * intentional to enforce typesafety.
1613 */
1614#define jbd2_alloc_handle(_gfp_flags) \
1615 ((handle_t *)kmem_cache_zalloc(jbd2_handle_cache, _gfp_flags))
1616
1617static inline void jbd2_free_handle(handle_t *handle)
1618{
1619 kmem_cache_free(jbd2_handle_cache, handle);
1620}
1621
1622/*
1623 * jbd2_inode management (optional, for those file systems that want to use
1624 * dynamically allocated jbd2_inode structures)
1625 */
1626extern struct kmem_cache *jbd2_inode_cache;
1627
1628/*
1629 * This specialized allocator has to be a macro for its allocations to be
1630 * accounted separately (to have a separate alloc_tag). The typecast is
1631 * intentional to enforce typesafety.
1632 */
1633#define jbd2_alloc_inode(_gfp_flags) \
1634 ((struct jbd2_inode *)kmem_cache_alloc(jbd2_inode_cache, _gfp_flags))
1635
1636static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1637{
1638 kmem_cache_free(jbd2_inode_cache, jinode);
1639}
1640
1641/* Primary revoke support */
1642#define JOURNAL_REVOKE_DEFAULT_HASH 256
1643extern int jbd2_journal_init_revoke(journal_t *, int);
1644extern void jbd2_journal_destroy_revoke_record_cache(void);
1645extern void jbd2_journal_destroy_revoke_table_cache(void);
1646extern int __init jbd2_journal_init_revoke_record_cache(void);
1647extern int __init jbd2_journal_init_revoke_table_cache(void);
1648struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size);
1649void jbd2_journal_destroy_revoke_table(struct jbd2_revoke_table_s *table);
1650
1651extern void jbd2_journal_destroy_revoke(journal_t *);
1652extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1653extern void jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1654extern void jbd2_journal_write_revoke_records(transaction_t *transaction,
1655 struct list_head *log_bufs);
1656
1657/* Recovery revoke support */
1658extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1659extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1660extern void jbd2_journal_clear_revoke(journal_t *);
1661extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1662extern void jbd2_clear_buffer_revoked_flags(journal_t *journal);
1663
1664/*
1665 * The log thread user interface:
1666 *
1667 * Request space in the current transaction, and force transaction commit
1668 * transitions on demand.
1669 */
1670
1671int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1672int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1673int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1674int jbd2_transaction_committed(journal_t *journal, tid_t tid);
1675int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1676int jbd2_log_do_checkpoint(journal_t *journal);
1677int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1678
1679void __jbd2_log_wait_for_space(journal_t *journal);
1680extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1681extern int jbd2_cleanup_journal_tail(journal_t *);
1682
1683/* Fast commit related APIs */
1684int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
1685int jbd2_fc_end_commit(journal_t *journal);
1686int jbd2_fc_end_commit_fallback(journal_t *journal);
1687int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
1688int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1689int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1690int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
1691void jbd2_fc_release_bufs(journal_t *journal);
1692
1693/*
1694 * is_journal_abort
1695 *
1696 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1697 * bit, when set, indicates that we have had a fatal error somewhere,
1698 * either inside the journaling layer or indicated to us by the client
1699 * (eg. ext3), and that we and should not commit any further
1700 * transactions.
1701 */
1702
1703static inline int is_journal_aborted(journal_t *journal)
1704{
1705 return journal->j_flags & JBD2_ABORT;
1706}
1707
1708static inline int is_handle_aborted(handle_t *handle)
1709{
1710 if (handle->h_aborted || !handle->h_transaction)
1711 return 1;
1712 return is_journal_aborted(handle->h_transaction->t_journal);
1713}
1714
1715static inline void jbd2_journal_abort_handle(handle_t *handle)
1716{
1717 handle->h_aborted = 1;
1718}
1719
1720static inline void jbd2_init_fs_dev_write_error(journal_t *journal)
1721{
1722 struct address_space *mapping = journal->j_fs_dev->bd_mapping;
1723
1724 /*
1725 * Save the original wb_err value of client fs's bdev mapping which
1726 * could be used to detect the client fs's metadata async write error.
1727 */
1728 errseq_check_and_advance(&mapping->wb_err, &journal->j_fs_dev_wb_err);
1729}
1730
1731static inline int jbd2_check_fs_dev_write_error(journal_t *journal)
1732{
1733 struct address_space *mapping = journal->j_fs_dev->bd_mapping;
1734
1735 return errseq_check(&mapping->wb_err,
1736 READ_ONCE(journal->j_fs_dev_wb_err));
1737}
1738
1739#endif /* __KERNEL__ */
1740
1741/* Comparison functions for transaction IDs: perform comparisons using
1742 * modulo arithmetic so that they work over sequence number wraps. */
1743
1744static inline int tid_gt(tid_t x, tid_t y)
1745{
1746 int difference = (x - y);
1747 return (difference > 0);
1748}
1749
1750static inline int tid_geq(tid_t x, tid_t y)
1751{
1752 int difference = (x - y);
1753 return (difference >= 0);
1754}
1755
1756extern int jbd2_journal_blocks_per_folio(struct inode *inode);
1757extern size_t journal_tag_bytes(journal_t *journal);
1758
1759static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1760{
1761 return jbd2_has_feature_csum2(journal) ||
1762 jbd2_has_feature_csum3(journal);
1763}
1764
1765static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb)
1766{
1767 int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks);
1768
1769 return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS;
1770}
1771
1772/*
1773 * Return number of free blocks in the log. Must be called under j_state_lock.
1774 */
1775static inline unsigned long jbd2_log_space_left(journal_t *journal)
1776{
1777 /* Allow for rounding errors */
1778 long free = journal->j_free - 32;
1779
1780 if (journal->j_committing_transaction) {
1781 free -= atomic_read(&journal->
1782 j_committing_transaction->t_outstanding_credits);
1783 }
1784 return max_t(long, free, 0);
1785}
1786
1787/*
1788 * Definitions which augment the buffer_head layer
1789 */
1790
1791/* journaling buffer types */
1792#define BJ_None 0 /* Not journaled */
1793#define BJ_Metadata 1 /* Normal journaled metadata */
1794#define BJ_Forget 2 /* Buffer superseded by this transaction */
1795#define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1796#define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1797#define BJ_Types 5
1798
1799static inline u32 jbd2_chksum(u32 crc, const void *address, unsigned int length)
1800{
1801 return crc32c(crc, address, length);
1802}
1803
1804/* Return most recent uncommitted transaction */
1805static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
1806{
1807 tid_t tid;
1808
1809 read_lock(&journal->j_state_lock);
1810 tid = journal->j_commit_request;
1811 if (journal->j_running_transaction)
1812 tid = journal->j_running_transaction->t_tid;
1813 read_unlock(&journal->j_state_lock);
1814 return tid;
1815}
1816
1817static inline int jbd2_handle_buffer_credits(handle_t *handle)
1818{
1819 journal_t *journal;
1820
1821 if (!handle->h_reserved)
1822 journal = handle->h_transaction->t_journal;
1823 else
1824 journal = handle->h_journal;
1825
1826 return handle->h_total_credits -
1827 DIV_ROUND_UP(handle->h_revoke_credits_requested,
1828 journal->j_revoke_records_per_block);
1829}
1830
1831#ifdef __KERNEL__
1832
1833#define buffer_trace_init(bh) do {} while (0)
1834#define print_buffer_fields(bh) do {} while (0)
1835#define print_buffer_trace(bh) do {} while (0)
1836#define BUFFER_TRACE(bh, info) do {} while (0)
1837#define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1838#define JBUFFER_TRACE(jh, info) do {} while (0)
1839
1840#endif /* __KERNEL__ */
1841
1842#endif /* _LINUX_JBD2_H */