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 <crypto/hash.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(bitnum: BH_JournalHead, addr: &bh->b_state);
344}
345
346static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
347{
348 bit_spin_unlock(bitnum: BH_JournalHead, addr: &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:
433 *
434 * Offset in bytes where the dirty range for this inode starts.
435 * [j_list_lock]
436 */
437 loff_t i_dirty_start;
438
439 /**
440 * @i_dirty_end:
441 *
442 * Inclusive offset in bytes where the dirty range for this inode
443 * ends. [j_list_lock]
444 */
445 loff_t i_dirty_end;
446};
447
448struct jbd2_revoke_table_s;
449
450/**
451 * struct jbd2_journal_handle - The jbd2_journal_handle type is the concrete
452 * type associated with handle_t.
453 * @h_transaction: Which compound transaction is this update a part of?
454 * @h_journal: Which journal handle belongs to - used iff h_reserved set.
455 * @h_rsv_handle: Handle reserved for finishing the logical operation.
456 * @h_total_credits: Number of remaining buffers we are allowed to add to
457 * journal. These are dirty buffers and revoke descriptor blocks.
458 * @h_revoke_credits: Number of remaining revoke records available for handle
459 * @h_ref: Reference count on this handle.
460 * @h_err: Field for caller's use to track errors through large fs operations.
461 * @h_sync: Flag for sync-on-close.
462 * @h_jdata: Flag to force data journaling.
463 * @h_reserved: Flag for handle for reserved credits.
464 * @h_aborted: Flag indicating fatal error on handle.
465 * @h_type: For handle statistics.
466 * @h_line_no: For handle statistics.
467 * @h_start_jiffies: Handle Start time.
468 * @h_requested_credits: Holds @h_total_credits after handle is started.
469 * @h_revoke_credits_requested: Holds @h_revoke_credits after handle is started.
470 * @saved_alloc_context: Saved context while transaction is open.
471 **/
472
473/* Docbook can't yet cope with the bit fields, but will leave the documentation
474 * in so it can be fixed later.
475 */
476
477struct jbd2_journal_handle
478{
479 union {
480 transaction_t *h_transaction;
481 /* Which journal handle belongs to - used iff h_reserved set */
482 journal_t *h_journal;
483 };
484
485 handle_t *h_rsv_handle;
486 int h_total_credits;
487 int h_revoke_credits;
488 int h_revoke_credits_requested;
489 int h_ref;
490 int h_err;
491
492 /* Flags [no locking] */
493 unsigned int h_sync: 1;
494 unsigned int h_jdata: 1;
495 unsigned int h_reserved: 1;
496 unsigned int h_aborted: 1;
497 unsigned int h_type: 8;
498 unsigned int h_line_no: 16;
499
500 unsigned long h_start_jiffies;
501 unsigned int h_requested_credits;
502
503 unsigned int saved_alloc_context;
504};
505
506
507/*
508 * Some stats for checkpoint phase
509 */
510struct transaction_chp_stats_s {
511 unsigned long cs_chp_time;
512 __u32 cs_forced_to_close;
513 __u32 cs_written;
514 __u32 cs_dropped;
515};
516
517/* The transaction_t type is the guts of the journaling mechanism. It
518 * tracks a compound transaction through its various states:
519 *
520 * RUNNING: accepting new updates
521 * LOCKED: Updates still running but we don't accept new ones
522 * RUNDOWN: Updates are tidying up but have finished requesting
523 * new buffers to modify (state not used for now)
524 * FLUSH: All updates complete, but we are still writing to disk
525 * COMMIT: All data on disk, writing commit record
526 * FINISHED: We still have to keep the transaction for checkpointing.
527 *
528 * The transaction keeps track of all of the buffers modified by a
529 * running transaction, and all of the buffers committed but not yet
530 * flushed to home for finished transactions.
531 * (Locking Documentation improved by LockDoc)
532 */
533
534/*
535 * Lock ranking:
536 *
537 * j_list_lock
538 * ->jbd_lock_bh_journal_head() (This is "innermost")
539 *
540 * j_state_lock
541 * ->b_state_lock
542 *
543 * b_state_lock
544 * ->j_list_lock
545 *
546 * j_state_lock
547 * ->j_list_lock (journal_unmap_buffer)
548 *
549 */
550
551struct transaction_s
552{
553 /* Pointer to the journal for this transaction. [no locking] */
554 journal_t *t_journal;
555
556 /* Sequence number for this transaction [no locking] */
557 tid_t t_tid;
558
559 /*
560 * Transaction's current state
561 * [no locking - only kjournald2 alters this]
562 * [j_list_lock] guards transition of a transaction into T_FINISHED
563 * state and subsequent call of __jbd2_journal_drop_transaction()
564 * FIXME: needs barriers
565 * KLUDGE: [use j_state_lock]
566 */
567 enum {
568 T_RUNNING,
569 T_LOCKED,
570 T_SWITCH,
571 T_FLUSH,
572 T_COMMIT,
573 T_COMMIT_DFLUSH,
574 T_COMMIT_JFLUSH,
575 T_COMMIT_CALLBACK,
576 T_FINISHED
577 } t_state;
578
579 /*
580 * Where in the log does this transaction's commit start? [no locking]
581 */
582 unsigned long t_log_start;
583
584 /*
585 * Number of buffers on the t_buffers list [j_list_lock, no locks
586 * needed for jbd2 thread]
587 */
588 int t_nr_buffers;
589
590 /*
591 * Doubly-linked circular list of all buffers reserved but not yet
592 * modified by this transaction [j_list_lock, no locks needed fo
593 * jbd2 thread]
594 */
595 struct journal_head *t_reserved_list;
596
597 /*
598 * Doubly-linked circular list of all metadata buffers owned by this
599 * transaction [j_list_lock, no locks needed for jbd2 thread]
600 */
601 struct journal_head *t_buffers;
602
603 /*
604 * Doubly-linked circular list of all forget buffers (superseded
605 * buffers which we can un-checkpoint once this transaction commits)
606 * [j_list_lock]
607 */
608 struct journal_head *t_forget;
609
610 /*
611 * Doubly-linked circular list of all buffers still to be flushed before
612 * this transaction can be checkpointed. [j_list_lock]
613 */
614 struct journal_head *t_checkpoint_list;
615
616 /*
617 * Doubly-linked circular list of metadata buffers being
618 * shadowed by log IO. The IO buffers on the iobuf list and
619 * the shadow buffers on this list match each other one for
620 * one at all times. [j_list_lock, no locks needed for jbd2
621 * thread]
622 */
623 struct journal_head *t_shadow_list;
624
625 /*
626 * List of inodes associated with the transaction; e.g., ext4 uses
627 * this to track inodes in data=ordered and data=journal mode that
628 * need special handling on transaction commit; also used by ocfs2.
629 * [j_list_lock]
630 */
631 struct list_head t_inode_list;
632
633 /*
634 * Longest time some handle had to wait for running transaction
635 */
636 unsigned long t_max_wait;
637
638 /*
639 * When transaction started
640 */
641 unsigned long t_start;
642
643 /*
644 * When commit was requested [j_state_lock]
645 */
646 unsigned long t_requested;
647
648 /*
649 * Checkpointing stats [j_list_lock]
650 */
651 struct transaction_chp_stats_s t_chp_stats;
652
653 /*
654 * Number of outstanding updates running on this transaction
655 * [none]
656 */
657 atomic_t t_updates;
658
659 /*
660 * Number of blocks reserved for this transaction in the journal.
661 * This is including all credits reserved when starting transaction
662 * handles as well as all journal descriptor blocks needed for this
663 * transaction. [none]
664 */
665 atomic_t t_outstanding_credits;
666
667 /*
668 * Number of revoke records for this transaction added by already
669 * stopped handles. [none]
670 */
671 atomic_t t_outstanding_revokes;
672
673 /*
674 * How many handles used this transaction? [none]
675 */
676 atomic_t t_handle_count;
677
678 /*
679 * Forward and backward links for the circular list of all transactions
680 * awaiting checkpoint. [j_list_lock]
681 */
682 transaction_t *t_cpnext, *t_cpprev;
683
684 /*
685 * When will the transaction expire (become due for commit), in jiffies?
686 * [no locking]
687 */
688 unsigned long t_expires;
689
690 /*
691 * When this transaction started, in nanoseconds [no locking]
692 */
693 ktime_t t_start_time;
694
695 /*
696 * This transaction is being forced and some process is
697 * waiting for it to finish.
698 */
699 unsigned int t_synchronous_commit:1;
700
701 /* Disk flush needs to be sent to fs partition [no locking] */
702 int t_need_data_flush;
703
704 /*
705 * For use by the filesystem to store fs-specific data
706 * structures associated with the transaction
707 */
708 struct list_head t_private_list;
709};
710
711struct transaction_run_stats_s {
712 unsigned long rs_wait;
713 unsigned long rs_request_delay;
714 unsigned long rs_running;
715 unsigned long rs_locked;
716 unsigned long rs_flushing;
717 unsigned long rs_logging;
718
719 __u32 rs_handle_count;
720 __u32 rs_blocks;
721 __u32 rs_blocks_logged;
722};
723
724struct transaction_stats_s {
725 unsigned long ts_tid;
726 unsigned long ts_requested;
727 struct transaction_run_stats_s run;
728};
729
730static inline unsigned long
731jbd2_time_diff(unsigned long start, unsigned long end)
732{
733 if (end >= start)
734 return end - start;
735
736 return end + (MAX_JIFFY_OFFSET - start);
737}
738
739#define JBD2_NR_BATCH 64
740
741enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
742
743#define JBD2_FC_REPLAY_STOP 0
744#define JBD2_FC_REPLAY_CONTINUE 1
745
746/**
747 * struct journal_s - The journal_s type is the concrete type associated with
748 * journal_t.
749 */
750struct journal_s
751{
752 /**
753 * @j_flags: General journaling state flags [j_state_lock,
754 * no lock for quick racy checks]
755 */
756 unsigned long j_flags;
757
758 /**
759 * @j_atomic_flags: Atomic journaling state flags.
760 */
761 unsigned long j_atomic_flags;
762
763 /**
764 * @j_errno:
765 *
766 * Is there an outstanding uncleared error on the journal (from a prior
767 * abort)? [j_state_lock]
768 */
769 int j_errno;
770
771 /**
772 * @j_abort_mutex: Lock the whole aborting procedure.
773 */
774 struct mutex j_abort_mutex;
775
776 /**
777 * @j_sb_buffer: The first part of the superblock buffer.
778 */
779 struct buffer_head *j_sb_buffer;
780
781 /**
782 * @j_superblock: The second part of the superblock buffer.
783 */
784 journal_superblock_t *j_superblock;
785
786 /**
787 * @j_state_lock: Protect the various scalars in the journal.
788 */
789 rwlock_t j_state_lock;
790
791 /**
792 * @j_barrier_count:
793 *
794 * Number of processes waiting to create a barrier lock [j_state_lock,
795 * no lock for quick racy checks]
796 */
797 int j_barrier_count;
798
799 /**
800 * @j_barrier: The barrier lock itself.
801 */
802 struct mutex j_barrier;
803
804 /**
805 * @j_running_transaction:
806 *
807 * Transactions: The current running transaction...
808 * [j_state_lock, no lock for quick racy checks] [caller holding
809 * open handle]
810 */
811 transaction_t *j_running_transaction;
812
813 /**
814 * @j_committing_transaction:
815 *
816 * the transaction we are pushing to disk
817 * [j_state_lock] [caller holding open handle]
818 */
819 transaction_t *j_committing_transaction;
820
821 /**
822 * @j_checkpoint_transactions:
823 *
824 * ... and a linked circular list of all transactions waiting for
825 * checkpointing. [j_list_lock]
826 */
827 transaction_t *j_checkpoint_transactions;
828
829 /**
830 * @j_wait_transaction_locked:
831 *
832 * Wait queue for waiting for a locked transaction to start committing,
833 * or for a barrier lock to be released.
834 */
835 wait_queue_head_t j_wait_transaction_locked;
836
837 /**
838 * @j_wait_done_commit: Wait queue for waiting for commit to complete.
839 */
840 wait_queue_head_t j_wait_done_commit;
841
842 /**
843 * @j_wait_commit: Wait queue to trigger commit.
844 */
845 wait_queue_head_t j_wait_commit;
846
847 /**
848 * @j_wait_updates: Wait queue to wait for updates to complete.
849 */
850 wait_queue_head_t j_wait_updates;
851
852 /**
853 * @j_wait_reserved:
854 *
855 * Wait queue to wait for reserved buffer credits to drop.
856 */
857 wait_queue_head_t j_wait_reserved;
858
859 /**
860 * @j_fc_wait:
861 *
862 * Wait queue to wait for completion of async fast commits.
863 */
864 wait_queue_head_t j_fc_wait;
865
866 /**
867 * @j_checkpoint_mutex:
868 *
869 * Semaphore for locking against concurrent checkpoints.
870 */
871 struct mutex j_checkpoint_mutex;
872
873 /**
874 * @j_chkpt_bhs:
875 *
876 * List of buffer heads used by the checkpoint routine. This
877 * was moved from jbd2_log_do_checkpoint() to reduce stack
878 * usage. Access to this array is controlled by the
879 * @j_checkpoint_mutex. [j_checkpoint_mutex]
880 */
881 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
882
883 /**
884 * @j_shrinker:
885 *
886 * Journal head shrinker, reclaim buffer's journal head which
887 * has been written back.
888 */
889 struct shrinker *j_shrinker;
890
891 /**
892 * @j_checkpoint_jh_count:
893 *
894 * Number of journal buffers on the checkpoint list. [j_list_lock]
895 */
896 struct percpu_counter j_checkpoint_jh_count;
897
898 /**
899 * @j_shrink_transaction:
900 *
901 * Record next transaction will shrink on the checkpoint list.
902 * [j_list_lock]
903 */
904 transaction_t *j_shrink_transaction;
905
906 /**
907 * @j_head:
908 *
909 * Journal head: identifies the first unused block in the journal.
910 * [j_state_lock]
911 */
912 unsigned long j_head;
913
914 /**
915 * @j_tail:
916 *
917 * Journal tail: identifies the oldest still-used block in the journal.
918 * [j_state_lock]
919 */
920 unsigned long j_tail;
921
922 /**
923 * @j_free:
924 *
925 * Journal free: how many free blocks are there in the journal?
926 * [j_state_lock]
927 */
928 unsigned long j_free;
929
930 /**
931 * @j_first:
932 *
933 * The block number of the first usable block in the journal
934 * [j_state_lock].
935 */
936 unsigned long j_first;
937
938 /**
939 * @j_last:
940 *
941 * The block number one beyond the last usable block in the journal
942 * [j_state_lock].
943 */
944 unsigned long j_last;
945
946 /**
947 * @j_fc_first:
948 *
949 * The block number of the first fast commit block in the journal
950 * [j_state_lock].
951 */
952 unsigned long j_fc_first;
953
954 /**
955 * @j_fc_off:
956 *
957 * Number of fast commit blocks currently allocated. Accessed only
958 * during fast commit. Currently only process can do fast commit, so
959 * this field is not protected by any lock.
960 */
961 unsigned long j_fc_off;
962
963 /**
964 * @j_fc_last:
965 *
966 * The block number one beyond the last fast commit block in the journal
967 * [j_state_lock].
968 */
969 unsigned long j_fc_last;
970
971 /**
972 * @j_dev: Device where we store the journal.
973 */
974 struct block_device *j_dev;
975
976 /**
977 * @j_blocksize: Block size for the location where we store the journal.
978 */
979 int j_blocksize;
980
981 /**
982 * @j_blk_offset:
983 *
984 * Starting block offset into the device where we store the journal.
985 */
986 unsigned long long j_blk_offset;
987
988 /**
989 * @j_devname: Journal device name.
990 */
991 char j_devname[BDEVNAME_SIZE+24];
992
993 /**
994 * @j_fs_dev:
995 *
996 * Device which holds the client fs. For internal journal this will be
997 * equal to j_dev.
998 */
999 struct block_device *j_fs_dev;
1000
1001 /**
1002 * @j_total_len: Total maximum capacity of the journal region on disk.
1003 */
1004 unsigned int j_total_len;
1005
1006 /**
1007 * @j_reserved_credits:
1008 *
1009 * Number of buffers reserved from the running transaction.
1010 */
1011 atomic_t j_reserved_credits;
1012
1013 /**
1014 * @j_list_lock: Protects the buffer lists and internal buffer state.
1015 */
1016 spinlock_t j_list_lock;
1017
1018 /**
1019 * @j_inode:
1020 *
1021 * Optional inode where we store the journal. If present, all
1022 * journal block numbers are mapped into this inode via bmap().
1023 */
1024 struct inode *j_inode;
1025
1026 /**
1027 * @j_tail_sequence:
1028 *
1029 * Sequence number of the oldest transaction in the log [j_state_lock]
1030 */
1031 tid_t j_tail_sequence;
1032
1033 /**
1034 * @j_transaction_sequence:
1035 *
1036 * Sequence number of the next transaction to grant [j_state_lock]
1037 */
1038 tid_t j_transaction_sequence;
1039
1040 /**
1041 * @j_commit_sequence:
1042 *
1043 * Sequence number of the most recently committed transaction
1044 * [j_state_lock, no lock for quick racy checks]
1045 */
1046 tid_t j_commit_sequence;
1047
1048 /**
1049 * @j_commit_request:
1050 *
1051 * Sequence number of the most recent transaction wanting commit
1052 * [j_state_lock, no lock for quick racy checks]
1053 */
1054 tid_t j_commit_request;
1055
1056 /**
1057 * @j_uuid:
1058 *
1059 * Journal uuid: identifies the object (filesystem, LVM volume etc)
1060 * backed by this journal. This will eventually be replaced by an array
1061 * of uuids, allowing us to index multiple devices within a single
1062 * journal and to perform atomic updates across them.
1063 */
1064 __u8 j_uuid[16];
1065
1066 /**
1067 * @j_task: Pointer to the current commit thread for this journal.
1068 */
1069 struct task_struct *j_task;
1070
1071 /**
1072 * @j_max_transaction_buffers:
1073 *
1074 * Maximum number of metadata buffers to allow in a single compound
1075 * commit transaction.
1076 */
1077 int j_max_transaction_buffers;
1078
1079 /**
1080 * @j_revoke_records_per_block:
1081 *
1082 * Number of revoke records that fit in one descriptor block.
1083 */
1084 int j_revoke_records_per_block;
1085
1086 /**
1087 * @j_commit_interval:
1088 *
1089 * What is the maximum transaction lifetime before we begin a commit?
1090 */
1091 unsigned long j_commit_interval;
1092
1093 /**
1094 * @j_commit_timer: The timer used to wakeup the commit thread.
1095 */
1096 struct timer_list j_commit_timer;
1097
1098 /**
1099 * @j_revoke_lock: Protect the revoke table.
1100 */
1101 spinlock_t j_revoke_lock;
1102
1103 /**
1104 * @j_revoke:
1105 *
1106 * The revoke table - maintains the list of revoked blocks in the
1107 * current transaction.
1108 */
1109 struct jbd2_revoke_table_s *j_revoke;
1110
1111 /**
1112 * @j_revoke_table: Alternate revoke tables for j_revoke.
1113 */
1114 struct jbd2_revoke_table_s *j_revoke_table[2];
1115
1116 /**
1117 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
1118 */
1119 struct buffer_head **j_wbuf;
1120
1121 /**
1122 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
1123 * during a fast commit. Currently only process can do fast commit, so
1124 * this field is not protected by any lock.
1125 */
1126 struct buffer_head **j_fc_wbuf;
1127
1128 /**
1129 * @j_wbufsize:
1130 *
1131 * Size of @j_wbuf array.
1132 */
1133 int j_wbufsize;
1134
1135 /**
1136 * @j_fc_wbufsize:
1137 *
1138 * Size of @j_fc_wbuf array.
1139 */
1140 int j_fc_wbufsize;
1141
1142 /**
1143 * @j_last_sync_writer:
1144 *
1145 * The pid of the last person to run a synchronous operation
1146 * through the journal.
1147 */
1148 pid_t j_last_sync_writer;
1149
1150 /**
1151 * @j_average_commit_time:
1152 *
1153 * The average amount of time in nanoseconds it takes to commit a
1154 * transaction to disk. [j_state_lock]
1155 */
1156 u64 j_average_commit_time;
1157
1158 /**
1159 * @j_min_batch_time:
1160 *
1161 * Minimum time that we should wait for additional filesystem operations
1162 * to get batched into a synchronous handle in microseconds.
1163 */
1164 u32 j_min_batch_time;
1165
1166 /**
1167 * @j_max_batch_time:
1168 *
1169 * Maximum time that we should wait for additional filesystem operations
1170 * to get batched into a synchronous handle in microseconds.
1171 */
1172 u32 j_max_batch_time;
1173
1174 /**
1175 * @j_commit_callback:
1176 *
1177 * This function is called when a transaction is closed.
1178 */
1179 void (*j_commit_callback)(journal_t *,
1180 transaction_t *);
1181
1182 /**
1183 * @j_submit_inode_data_buffers:
1184 *
1185 * This function is called for all inodes associated with the
1186 * committing transaction marked with JI_WRITE_DATA flag
1187 * before we start to write out the transaction to the journal.
1188 */
1189 int (*j_submit_inode_data_buffers)
1190 (struct jbd2_inode *);
1191
1192 /**
1193 * @j_finish_inode_data_buffers:
1194 *
1195 * This function is called for all inodes associated with the
1196 * committing transaction marked with JI_WAIT_DATA flag
1197 * after we have written the transaction to the journal
1198 * but before we write out the commit block.
1199 */
1200 int (*j_finish_inode_data_buffers)
1201 (struct jbd2_inode *);
1202
1203 /*
1204 * Journal statistics
1205 */
1206
1207 /**
1208 * @j_history_lock: Protect the transactions statistics history.
1209 */
1210 spinlock_t j_history_lock;
1211
1212 /**
1213 * @j_proc_entry: procfs entry for the jbd statistics directory.
1214 */
1215 struct proc_dir_entry *j_proc_entry;
1216
1217 /**
1218 * @j_stats: Overall statistics.
1219 */
1220 struct transaction_stats_s j_stats;
1221
1222 /**
1223 * @j_failed_commit: Failed journal commit ID.
1224 */
1225 unsigned int j_failed_commit;
1226
1227 /**
1228 * @j_private:
1229 *
1230 * An opaque pointer to fs-private information. ext3 puts its
1231 * superblock pointer here.
1232 */
1233 void *j_private;
1234
1235 /**
1236 * @j_chksum_driver:
1237 *
1238 * Reference to checksum algorithm driver via cryptoapi.
1239 */
1240 struct crypto_shash *j_chksum_driver;
1241
1242 /**
1243 * @j_csum_seed:
1244 *
1245 * Precomputed journal UUID checksum for seeding other checksums.
1246 */
1247 __u32 j_csum_seed;
1248
1249#ifdef CONFIG_DEBUG_LOCK_ALLOC
1250 /**
1251 * @j_trans_commit_map:
1252 *
1253 * Lockdep entity to track transaction commit dependencies. Handles
1254 * hold this "lock" for read, when we wait for commit, we acquire the
1255 * "lock" for writing. This matches the properties of jbd2 journalling
1256 * where the running transaction has to wait for all handles to be
1257 * dropped to commit that transaction and also acquiring a handle may
1258 * require transaction commit to finish.
1259 */
1260 struct lockdep_map j_trans_commit_map;
1261#endif
1262
1263 /**
1264 * @j_fc_cleanup_callback:
1265 *
1266 * Clean-up after fast commit or full commit. JBD2 calls this function
1267 * after every commit operation.
1268 */
1269 void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
1270
1271 /**
1272 * @j_fc_replay_callback:
1273 *
1274 * File-system specific function that performs replay of a fast
1275 * commit. JBD2 calls this function for each fast commit block found in
1276 * the journal. This function should return JBD2_FC_REPLAY_CONTINUE
1277 * to indicate that the block was processed correctly and more fast
1278 * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP
1279 * indicates the end of replay (no more blocks remaining). A negative
1280 * return value indicates error.
1281 */
1282 int (*j_fc_replay_callback)(struct journal_s *journal,
1283 struct buffer_head *bh,
1284 enum passtype pass, int off,
1285 tid_t expected_commit_id);
1286
1287 /**
1288 * @j_bmap:
1289 *
1290 * Bmap function that should be used instead of the generic
1291 * VFS bmap function.
1292 */
1293 int (*j_bmap)(struct journal_s *journal, sector_t *block);
1294};
1295
1296#define jbd2_might_wait_for_commit(j) \
1297 do { \
1298 rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
1299 rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
1300 } while (0)
1301
1302/*
1303 * We can support any known requested features iff the
1304 * superblock is not in version 1. Otherwise we fail to support any
1305 * extended sb features.
1306 */
1307static inline bool jbd2_format_support_feature(journal_t *j)
1308{
1309 return j->j_superblock->s_header.h_blocktype !=
1310 cpu_to_be32(JBD2_SUPERBLOCK_V1);
1311}
1312
1313/* journal feature predicate functions */
1314#define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1315static inline bool jbd2_has_feature_##name(journal_t *j) \
1316{ \
1317 return (jbd2_format_support_feature(j) && \
1318 ((j)->j_superblock->s_feature_compat & \
1319 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1320} \
1321static inline void jbd2_set_feature_##name(journal_t *j) \
1322{ \
1323 (j)->j_superblock->s_feature_compat |= \
1324 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1325} \
1326static inline void jbd2_clear_feature_##name(journal_t *j) \
1327{ \
1328 (j)->j_superblock->s_feature_compat &= \
1329 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1330}
1331
1332#define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1333static inline bool jbd2_has_feature_##name(journal_t *j) \
1334{ \
1335 return (jbd2_format_support_feature(j) && \
1336 ((j)->j_superblock->s_feature_ro_compat & \
1337 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1338} \
1339static inline void jbd2_set_feature_##name(journal_t *j) \
1340{ \
1341 (j)->j_superblock->s_feature_ro_compat |= \
1342 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1343} \
1344static inline void jbd2_clear_feature_##name(journal_t *j) \
1345{ \
1346 (j)->j_superblock->s_feature_ro_compat &= \
1347 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1348}
1349
1350#define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1351static inline bool jbd2_has_feature_##name(journal_t *j) \
1352{ \
1353 return (jbd2_format_support_feature(j) && \
1354 ((j)->j_superblock->s_feature_incompat & \
1355 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1356} \
1357static inline void jbd2_set_feature_##name(journal_t *j) \
1358{ \
1359 (j)->j_superblock->s_feature_incompat |= \
1360 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1361} \
1362static inline void jbd2_clear_feature_##name(journal_t *j) \
1363{ \
1364 (j)->j_superblock->s_feature_incompat &= \
1365 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1366}
1367
1368JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
1369
1370JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
1371JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
1372JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
1373JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
1374JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
1375JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT)
1376
1377/*
1378 * Journal flag definitions
1379 */
1380#define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1381#define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1382#define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1383#define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1384#define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1385#define JBD2_BARRIER 0x020 /* Use IDE barriers */
1386#define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
1387 * data write error in ordered
1388 * mode */
1389#define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on
1390 * clean and empty filesystem
1391 * logging area */
1392#define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */
1393#define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
1394#define JBD2_JOURNAL_FLUSH_DISCARD 0x0001
1395#define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002
1396#define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \
1397 JBD2_JOURNAL_FLUSH_ZEROOUT)
1398
1399/*
1400 * Journal atomic flag definitions
1401 */
1402#define JBD2_CHECKPOINT_IO_ERROR 0x001 /* Detect io error while writing
1403 * buffer back to disk */
1404
1405/*
1406 * Function declarations for the journaling transaction and buffer
1407 * management
1408 */
1409
1410/* Filing buffers */
1411extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
1412extern bool __jbd2_journal_refile_buffer(struct journal_head *);
1413extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1414extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1415extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1416static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1417{
1418 list_add_tail(new: &bh->b_assoc_buffers, head);
1419}
1420static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1421{
1422 list_del_init(entry: &bh->b_assoc_buffers);
1423}
1424
1425/* Log buffer allocation */
1426struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
1427void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
1428int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1429int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1430 unsigned long *block);
1431int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1432void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1433
1434/* Commit management */
1435extern void jbd2_journal_commit_transaction(journal_t *);
1436
1437/* Checkpoint list management */
1438void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
1439unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
1440int __jbd2_journal_remove_checkpoint(struct journal_head *);
1441int jbd2_journal_try_remove_checkpoint(struct journal_head *jh);
1442void jbd2_journal_destroy_checkpoint(journal_t *journal);
1443void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1444
1445
1446/*
1447 * Triggers
1448 */
1449
1450struct jbd2_buffer_trigger_type {
1451 /*
1452 * Fired a the moment data to write to the journal are known to be
1453 * stable - so either at the moment b_frozen_data is created or just
1454 * before a buffer is written to the journal. mapped_data is a mapped
1455 * buffer that is the frozen data for commit.
1456 */
1457 void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1458 struct buffer_head *bh, void *mapped_data,
1459 size_t size);
1460
1461 /*
1462 * Fired during journal abort for dirty buffers that will not be
1463 * committed.
1464 */
1465 void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1466 struct buffer_head *bh);
1467};
1468
1469extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1470 void *mapped_data,
1471 struct jbd2_buffer_trigger_type *triggers);
1472extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1473 struct jbd2_buffer_trigger_type *triggers);
1474
1475/* Buffer IO */
1476extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1477 struct journal_head *jh_in,
1478 struct buffer_head **bh_out,
1479 sector_t blocknr);
1480
1481/* Transaction cache support */
1482extern void jbd2_journal_destroy_transaction_cache(void);
1483extern int __init jbd2_journal_init_transaction_cache(void);
1484extern void jbd2_journal_free_transaction(transaction_t *);
1485
1486/*
1487 * Journal locking.
1488 *
1489 * We need to lock the journal during transaction state changes so that nobody
1490 * ever tries to take a handle on the running transaction while we are in the
1491 * middle of moving it to the commit phase. j_state_lock does this.
1492 *
1493 * Note that the locking is completely interrupt unsafe. We never touch
1494 * journal structures from interrupts.
1495 */
1496
1497static inline handle_t *journal_current_handle(void)
1498{
1499 return current->journal_info;
1500}
1501
1502/* The journaling code user interface:
1503 *
1504 * Create and destroy handles
1505 * Register buffer modifications against the current transaction.
1506 */
1507
1508extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1509extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1510 int revoke_records, gfp_t gfp_mask,
1511 unsigned int type, unsigned int line_no);
1512extern int jbd2_journal_restart(handle_t *, int nblocks);
1513extern int jbd2__journal_restart(handle_t *, int nblocks,
1514 int revoke_records, gfp_t gfp_mask);
1515extern int jbd2_journal_start_reserved(handle_t *handle,
1516 unsigned int type, unsigned int line_no);
1517extern void jbd2_journal_free_reserved(handle_t *handle);
1518extern int jbd2_journal_extend(handle_t *handle, int nblocks,
1519 int revoke_records);
1520extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1521extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1522extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1523void jbd2_journal_set_triggers(struct buffer_head *,
1524 struct jbd2_buffer_trigger_type *type);
1525extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1526extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1527int jbd2_journal_invalidate_folio(journal_t *, struct folio *,
1528 size_t offset, size_t length);
1529bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio);
1530extern int jbd2_journal_stop(handle_t *);
1531extern int jbd2_journal_flush(journal_t *journal, unsigned int flags);
1532extern void jbd2_journal_lock_updates (journal_t *);
1533extern void jbd2_journal_unlock_updates (journal_t *);
1534
1535void jbd2_journal_wait_updates(journal_t *);
1536
1537extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1538 struct block_device *fs_dev,
1539 unsigned long long start, int len, int bsize);
1540extern journal_t * jbd2_journal_init_inode (struct inode *);
1541extern int jbd2_journal_update_format (journal_t *);
1542extern int jbd2_journal_check_used_features
1543 (journal_t *, unsigned long, unsigned long, unsigned long);
1544extern int jbd2_journal_check_available_features
1545 (journal_t *, unsigned long, unsigned long, unsigned long);
1546extern int jbd2_journal_set_features
1547 (journal_t *, unsigned long, unsigned long, unsigned long);
1548extern void jbd2_journal_clear_features
1549 (journal_t *, unsigned long, unsigned long, unsigned long);
1550extern int jbd2_journal_load (journal_t *journal);
1551extern int jbd2_journal_destroy (journal_t *);
1552extern int jbd2_journal_recover (journal_t *journal);
1553extern int jbd2_journal_wipe (journal_t *, int);
1554extern int jbd2_journal_skip_recovery (journal_t *);
1555extern void jbd2_journal_update_sb_errno(journal_t *);
1556extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t,
1557 unsigned long, blk_opf_t);
1558extern void jbd2_journal_abort (journal_t *, int);
1559extern int jbd2_journal_errno (journal_t *);
1560extern void jbd2_journal_ack_err (journal_t *);
1561extern int jbd2_journal_clear_err (journal_t *);
1562extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1563extern int jbd2_journal_force_commit(journal_t *);
1564extern int jbd2_journal_force_commit_nested(journal_t *);
1565extern int jbd2_journal_inode_ranged_write(handle_t *handle,
1566 struct jbd2_inode *inode, loff_t start_byte,
1567 loff_t length);
1568extern int jbd2_journal_inode_ranged_wait(handle_t *handle,
1569 struct jbd2_inode *inode, loff_t start_byte,
1570 loff_t length);
1571extern int jbd2_journal_finish_inode_data_buffers(
1572 struct jbd2_inode *jinode);
1573extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
1574 struct jbd2_inode *inode, loff_t new_size);
1575extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1576extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1577
1578/*
1579 * journal_head management
1580 */
1581struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1582struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1583void jbd2_journal_put_journal_head(struct journal_head *jh);
1584
1585/*
1586 * handle management
1587 */
1588extern struct kmem_cache *jbd2_handle_cache;
1589
1590static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1591{
1592 return kmem_cache_zalloc(k: jbd2_handle_cache, flags: gfp_flags);
1593}
1594
1595static inline void jbd2_free_handle(handle_t *handle)
1596{
1597 kmem_cache_free(s: jbd2_handle_cache, objp: handle);
1598}
1599
1600/*
1601 * jbd2_inode management (optional, for those file systems that want to use
1602 * dynamically allocated jbd2_inode structures)
1603 */
1604extern struct kmem_cache *jbd2_inode_cache;
1605
1606static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1607{
1608 return kmem_cache_alloc(cachep: jbd2_inode_cache, flags: gfp_flags);
1609}
1610
1611static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1612{
1613 kmem_cache_free(s: jbd2_inode_cache, objp: jinode);
1614}
1615
1616/* Primary revoke support */
1617#define JOURNAL_REVOKE_DEFAULT_HASH 256
1618extern int jbd2_journal_init_revoke(journal_t *, int);
1619extern void jbd2_journal_destroy_revoke_record_cache(void);
1620extern void jbd2_journal_destroy_revoke_table_cache(void);
1621extern int __init jbd2_journal_init_revoke_record_cache(void);
1622extern int __init jbd2_journal_init_revoke_table_cache(void);
1623
1624extern void jbd2_journal_destroy_revoke(journal_t *);
1625extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1626extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1627extern void jbd2_journal_write_revoke_records(transaction_t *transaction,
1628 struct list_head *log_bufs);
1629
1630/* Recovery revoke support */
1631extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1632extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1633extern void jbd2_journal_clear_revoke(journal_t *);
1634extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1635extern void jbd2_clear_buffer_revoked_flags(journal_t *journal);
1636
1637/*
1638 * The log thread user interface:
1639 *
1640 * Request space in the current transaction, and force transaction commit
1641 * transitions on demand.
1642 */
1643
1644int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1645int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1646int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1647int jbd2_transaction_committed(journal_t *journal, tid_t tid);
1648int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1649int jbd2_log_do_checkpoint(journal_t *journal);
1650int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1651
1652void __jbd2_log_wait_for_space(journal_t *journal);
1653extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1654extern int jbd2_cleanup_journal_tail(journal_t *);
1655
1656/* Fast commit related APIs */
1657int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
1658int jbd2_fc_end_commit(journal_t *journal);
1659int jbd2_fc_end_commit_fallback(journal_t *journal);
1660int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
1661int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1662int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1663int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
1664int jbd2_fc_release_bufs(journal_t *journal);
1665
1666static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal)
1667{
1668 return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
1669}
1670
1671/*
1672 * is_journal_abort
1673 *
1674 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1675 * bit, when set, indicates that we have had a fatal error somewhere,
1676 * either inside the journaling layer or indicated to us by the client
1677 * (eg. ext3), and that we and should not commit any further
1678 * transactions.
1679 */
1680
1681static inline int is_journal_aborted(journal_t *journal)
1682{
1683 return journal->j_flags & JBD2_ABORT;
1684}
1685
1686static inline int is_handle_aborted(handle_t *handle)
1687{
1688 if (handle->h_aborted || !handle->h_transaction)
1689 return 1;
1690 return is_journal_aborted(journal: handle->h_transaction->t_journal);
1691}
1692
1693static inline void jbd2_journal_abort_handle(handle_t *handle)
1694{
1695 handle->h_aborted = 1;
1696}
1697
1698#endif /* __KERNEL__ */
1699
1700/* Comparison functions for transaction IDs: perform comparisons using
1701 * modulo arithmetic so that they work over sequence number wraps. */
1702
1703static inline int tid_gt(tid_t x, tid_t y)
1704{
1705 int difference = (x - y);
1706 return (difference > 0);
1707}
1708
1709static inline int tid_geq(tid_t x, tid_t y)
1710{
1711 int difference = (x - y);
1712 return (difference >= 0);
1713}
1714
1715extern int jbd2_journal_blocks_per_page(struct inode *inode);
1716extern size_t journal_tag_bytes(journal_t *journal);
1717
1718static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
1719{
1720 return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j);
1721}
1722
1723static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1724{
1725 WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) &&
1726 journal->j_chksum_driver == NULL);
1727
1728 return journal->j_chksum_driver != NULL;
1729}
1730
1731static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb)
1732{
1733 int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks);
1734
1735 return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS;
1736}
1737
1738/*
1739 * Return number of free blocks in the log. Must be called under j_state_lock.
1740 */
1741static inline unsigned long jbd2_log_space_left(journal_t *journal)
1742{
1743 /* Allow for rounding errors */
1744 long free = journal->j_free - 32;
1745
1746 if (journal->j_committing_transaction) {
1747 free -= atomic_read(v: &journal->
1748 j_committing_transaction->t_outstanding_credits);
1749 }
1750 return max_t(long, free, 0);
1751}
1752
1753/*
1754 * Definitions which augment the buffer_head layer
1755 */
1756
1757/* journaling buffer types */
1758#define BJ_None 0 /* Not journaled */
1759#define BJ_Metadata 1 /* Normal journaled metadata */
1760#define BJ_Forget 2 /* Buffer superseded by this transaction */
1761#define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1762#define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1763#define BJ_Types 5
1764
1765/* JBD uses a CRC32 checksum */
1766#define JBD_MAX_CHECKSUM_SIZE 4
1767
1768static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
1769 const void *address, unsigned int length)
1770{
1771 struct {
1772 struct shash_desc shash;
1773 char ctx[JBD_MAX_CHECKSUM_SIZE];
1774 } desc;
1775 int err;
1776
1777 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
1778 JBD_MAX_CHECKSUM_SIZE);
1779
1780 desc.shash.tfm = journal->j_chksum_driver;
1781 *(u32 *)desc.ctx = crc;
1782
1783 err = crypto_shash_update(desc: &desc.shash, data: address, len: length);
1784 BUG_ON(err);
1785
1786 return *(u32 *)desc.ctx;
1787}
1788
1789/* Return most recent uncommitted transaction */
1790static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
1791{
1792 tid_t tid;
1793
1794 read_lock(&journal->j_state_lock);
1795 tid = journal->j_commit_request;
1796 if (journal->j_running_transaction)
1797 tid = journal->j_running_transaction->t_tid;
1798 read_unlock(&journal->j_state_lock);
1799 return tid;
1800}
1801
1802static inline int jbd2_handle_buffer_credits(handle_t *handle)
1803{
1804 journal_t *journal;
1805
1806 if (!handle->h_reserved)
1807 journal = handle->h_transaction->t_journal;
1808 else
1809 journal = handle->h_journal;
1810
1811 return handle->h_total_credits -
1812 DIV_ROUND_UP(handle->h_revoke_credits_requested,
1813 journal->j_revoke_records_per_block);
1814}
1815
1816#ifdef __KERNEL__
1817
1818#define buffer_trace_init(bh) do {} while (0)
1819#define print_buffer_fields(bh) do {} while (0)
1820#define print_buffer_trace(bh) do {} while (0)
1821#define BUFFER_TRACE(bh, info) do {} while (0)
1822#define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1823#define JBUFFER_TRACE(jh, info) do {} while (0)
1824
1825#endif /* __KERNEL__ */
1826
1827#define EFSBADCRC EBADMSG /* Bad CRC detected */
1828#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
1829
1830#endif /* _LINUX_JBD2_H */
1831

source code of linux/include/linux/jbd2.h