Line data Source code
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
57 : void __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 :
66 : extern void *jbd2_alloc(size_t size, gfp_t flags);
67 : extern 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 : **/
91 : typedef 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 : **/
105 : typedef 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 : */
131 : typedef 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 : */
167 : struct 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 : */
185 : typedef 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 :
193 : typedef 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 */
202 : struct 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 : */
210 : typedef 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 : */
226 : typedef 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 :
305 : enum 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 :
319 0 : BUFFER_FNS(JBD, jbd)
320 0 : BUFFER_FNS(JWrite, jwrite)
321 0 : BUFFER_FNS(JBDDirty, jbddirty)
322 0 : TAS_BUFFER_FNS(JBDDirty, jbddirty)
323 0 : BUFFER_FNS(Revoked, revoked)
324 0 : TAS_BUFFER_FNS(Revoked, revoked)
325 0 : BUFFER_FNS(RevokeValid, revokevalid)
326 0 : TAS_BUFFER_FNS(RevokeValid, revokevalid)
327 0 : BUFFER_FNS(Freed, freed)
328 0 : BUFFER_FNS(Shadow, shadow)
329 2 : BUFFER_FNS(Verified, verified)
330 :
331 : static inline struct buffer_head *jh2bh(struct journal_head *jh)
332 : {
333 0 : return jh->b_bh;
334 : }
335 :
336 : static inline struct journal_head *bh2jh(struct buffer_head *bh)
337 : {
338 0 : return bh->b_private;
339 : }
340 :
341 : static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
342 : {
343 0 : bit_spin_lock(BH_JournalHead, &bh->b_state);
344 : }
345 :
346 : static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
347 : {
348 0 : bit_spin_unlock(BH_JournalHead, &bh->b_state);
349 0 : }
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 : */
397 : struct 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 :
448 : struct 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 :
477 : struct 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 : */
510 : struct 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 :
551 : struct 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 : * Protects info related to handles
635 : */
636 : spinlock_t t_handle_lock;
637 :
638 : /*
639 : * Longest time some handle had to wait for running transaction
640 : */
641 : unsigned long t_max_wait;
642 :
643 : /*
644 : * When transaction started
645 : */
646 : unsigned long t_start;
647 :
648 : /*
649 : * When commit was requested [j_state_lock]
650 : */
651 : unsigned long t_requested;
652 :
653 : /*
654 : * Checkpointing stats [j_list_lock]
655 : */
656 : struct transaction_chp_stats_s t_chp_stats;
657 :
658 : /*
659 : * Number of outstanding updates running on this transaction
660 : * [none]
661 : */
662 : atomic_t t_updates;
663 :
664 : /*
665 : * Number of blocks reserved for this transaction in the journal.
666 : * This is including all credits reserved when starting transaction
667 : * handles as well as all journal descriptor blocks needed for this
668 : * transaction. [none]
669 : */
670 : atomic_t t_outstanding_credits;
671 :
672 : /*
673 : * Number of revoke records for this transaction added by already
674 : * stopped handles. [none]
675 : */
676 : atomic_t t_outstanding_revokes;
677 :
678 : /*
679 : * How many handles used this transaction? [none]
680 : */
681 : atomic_t t_handle_count;
682 :
683 : /*
684 : * Forward and backward links for the circular list of all transactions
685 : * awaiting checkpoint. [j_list_lock]
686 : */
687 : transaction_t *t_cpnext, *t_cpprev;
688 :
689 : /*
690 : * When will the transaction expire (become due for commit), in jiffies?
691 : * [no locking]
692 : */
693 : unsigned long t_expires;
694 :
695 : /*
696 : * When this transaction started, in nanoseconds [no locking]
697 : */
698 : ktime_t t_start_time;
699 :
700 : /*
701 : * This transaction is being forced and some process is
702 : * waiting for it to finish.
703 : */
704 : unsigned int t_synchronous_commit:1;
705 :
706 : /* Disk flush needs to be sent to fs partition [no locking] */
707 : int t_need_data_flush;
708 :
709 : /*
710 : * For use by the filesystem to store fs-specific data
711 : * structures associated with the transaction
712 : */
713 : struct list_head t_private_list;
714 : };
715 :
716 : struct transaction_run_stats_s {
717 : unsigned long rs_wait;
718 : unsigned long rs_request_delay;
719 : unsigned long rs_running;
720 : unsigned long rs_locked;
721 : unsigned long rs_flushing;
722 : unsigned long rs_logging;
723 :
724 : __u32 rs_handle_count;
725 : __u32 rs_blocks;
726 : __u32 rs_blocks_logged;
727 : };
728 :
729 : struct transaction_stats_s {
730 : unsigned long ts_tid;
731 : unsigned long ts_requested;
732 : struct transaction_run_stats_s run;
733 : };
734 :
735 : static inline unsigned long
736 : jbd2_time_diff(unsigned long start, unsigned long end)
737 : {
738 0 : if (end >= start)
739 0 : return end - start;
740 :
741 0 : return end + (MAX_JIFFY_OFFSET - start);
742 : }
743 :
744 : #define JBD2_NR_BATCH 64
745 :
746 : enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
747 :
748 : #define JBD2_FC_REPLAY_STOP 0
749 : #define JBD2_FC_REPLAY_CONTINUE 1
750 :
751 : /**
752 : * struct journal_s - The journal_s type is the concrete type associated with
753 : * journal_t.
754 : */
755 : struct journal_s
756 : {
757 : /**
758 : * @j_flags: General journaling state flags [j_state_lock,
759 : * no lock for quick racy checks]
760 : */
761 : unsigned long j_flags;
762 :
763 : /**
764 : * @j_atomic_flags: Atomic journaling state flags.
765 : */
766 : unsigned long j_atomic_flags;
767 :
768 : /**
769 : * @j_errno:
770 : *
771 : * Is there an outstanding uncleared error on the journal (from a prior
772 : * abort)? [j_state_lock]
773 : */
774 : int j_errno;
775 :
776 : /**
777 : * @j_abort_mutex: Lock the whole aborting procedure.
778 : */
779 : struct mutex j_abort_mutex;
780 :
781 : /**
782 : * @j_sb_buffer: The first part of the superblock buffer.
783 : */
784 : struct buffer_head *j_sb_buffer;
785 :
786 : /**
787 : * @j_superblock: The second part of the superblock buffer.
788 : */
789 : journal_superblock_t *j_superblock;
790 :
791 : /**
792 : * @j_state_lock: Protect the various scalars in the journal.
793 : */
794 : rwlock_t j_state_lock;
795 :
796 : /**
797 : * @j_barrier_count:
798 : *
799 : * Number of processes waiting to create a barrier lock [j_state_lock,
800 : * no lock for quick racy checks]
801 : */
802 : int j_barrier_count;
803 :
804 : /**
805 : * @j_barrier: The barrier lock itself.
806 : */
807 : struct mutex j_barrier;
808 :
809 : /**
810 : * @j_running_transaction:
811 : *
812 : * Transactions: The current running transaction...
813 : * [j_state_lock, no lock for quick racy checks] [caller holding
814 : * open handle]
815 : */
816 : transaction_t *j_running_transaction;
817 :
818 : /**
819 : * @j_committing_transaction:
820 : *
821 : * the transaction we are pushing to disk
822 : * [j_state_lock] [caller holding open handle]
823 : */
824 : transaction_t *j_committing_transaction;
825 :
826 : /**
827 : * @j_checkpoint_transactions:
828 : *
829 : * ... and a linked circular list of all transactions waiting for
830 : * checkpointing. [j_list_lock]
831 : */
832 : transaction_t *j_checkpoint_transactions;
833 :
834 : /**
835 : * @j_wait_transaction_locked:
836 : *
837 : * Wait queue for waiting for a locked transaction to start committing,
838 : * or for a barrier lock to be released.
839 : */
840 : wait_queue_head_t j_wait_transaction_locked;
841 :
842 : /**
843 : * @j_wait_done_commit: Wait queue for waiting for commit to complete.
844 : */
845 : wait_queue_head_t j_wait_done_commit;
846 :
847 : /**
848 : * @j_wait_commit: Wait queue to trigger commit.
849 : */
850 : wait_queue_head_t j_wait_commit;
851 :
852 : /**
853 : * @j_wait_updates: Wait queue to wait for updates to complete.
854 : */
855 : wait_queue_head_t j_wait_updates;
856 :
857 : /**
858 : * @j_wait_reserved:
859 : *
860 : * Wait queue to wait for reserved buffer credits to drop.
861 : */
862 : wait_queue_head_t j_wait_reserved;
863 :
864 : /**
865 : * @j_fc_wait:
866 : *
867 : * Wait queue to wait for completion of async fast commits.
868 : */
869 : wait_queue_head_t j_fc_wait;
870 :
871 : /**
872 : * @j_checkpoint_mutex:
873 : *
874 : * Semaphore for locking against concurrent checkpoints.
875 : */
876 : struct mutex j_checkpoint_mutex;
877 :
878 : /**
879 : * @j_chkpt_bhs:
880 : *
881 : * List of buffer heads used by the checkpoint routine. This
882 : * was moved from jbd2_log_do_checkpoint() to reduce stack
883 : * usage. Access to this array is controlled by the
884 : * @j_checkpoint_mutex. [j_checkpoint_mutex]
885 : */
886 : struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
887 :
888 : /**
889 : * @j_shrinker:
890 : *
891 : * Journal head shrinker, reclaim buffer's journal head which
892 : * has been written back.
893 : */
894 : struct shrinker j_shrinker;
895 :
896 : /**
897 : * @j_checkpoint_jh_count:
898 : *
899 : * Number of journal buffers on the checkpoint list. [j_list_lock]
900 : */
901 : struct percpu_counter j_checkpoint_jh_count;
902 :
903 : /**
904 : * @j_shrink_transaction:
905 : *
906 : * Record next transaction will shrink on the checkpoint list.
907 : * [j_list_lock]
908 : */
909 : transaction_t *j_shrink_transaction;
910 :
911 : /**
912 : * @j_head:
913 : *
914 : * Journal head: identifies the first unused block in the journal.
915 : * [j_state_lock]
916 : */
917 : unsigned long j_head;
918 :
919 : /**
920 : * @j_tail:
921 : *
922 : * Journal tail: identifies the oldest still-used block in the journal.
923 : * [j_state_lock]
924 : */
925 : unsigned long j_tail;
926 :
927 : /**
928 : * @j_free:
929 : *
930 : * Journal free: how many free blocks are there in the journal?
931 : * [j_state_lock]
932 : */
933 : unsigned long j_free;
934 :
935 : /**
936 : * @j_first:
937 : *
938 : * The block number of the first usable block in the journal
939 : * [j_state_lock].
940 : */
941 : unsigned long j_first;
942 :
943 : /**
944 : * @j_last:
945 : *
946 : * The block number one beyond the last usable block in the journal
947 : * [j_state_lock].
948 : */
949 : unsigned long j_last;
950 :
951 : /**
952 : * @j_fc_first:
953 : *
954 : * The block number of the first fast commit block in the journal
955 : * [j_state_lock].
956 : */
957 : unsigned long j_fc_first;
958 :
959 : /**
960 : * @j_fc_off:
961 : *
962 : * Number of fast commit blocks currently allocated. Accessed only
963 : * during fast commit. Currently only process can do fast commit, so
964 : * this field is not protected by any lock.
965 : */
966 : unsigned long j_fc_off;
967 :
968 : /**
969 : * @j_fc_last:
970 : *
971 : * The block number one beyond the last fast commit block in the journal
972 : * [j_state_lock].
973 : */
974 : unsigned long j_fc_last;
975 :
976 : /**
977 : * @j_dev: Device where we store the journal.
978 : */
979 : struct block_device *j_dev;
980 :
981 : /**
982 : * @j_blocksize: Block size for the location where we store the journal.
983 : */
984 : int j_blocksize;
985 :
986 : /**
987 : * @j_blk_offset:
988 : *
989 : * Starting block offset into the device where we store the journal.
990 : */
991 : unsigned long long j_blk_offset;
992 :
993 : /**
994 : * @j_devname: Journal device name.
995 : */
996 : char j_devname[BDEVNAME_SIZE+24];
997 :
998 : /**
999 : * @j_fs_dev:
1000 : *
1001 : * Device which holds the client fs. For internal journal this will be
1002 : * equal to j_dev.
1003 : */
1004 : struct block_device *j_fs_dev;
1005 :
1006 : /**
1007 : * @j_total_len: Total maximum capacity of the journal region on disk.
1008 : */
1009 : unsigned int j_total_len;
1010 :
1011 : /**
1012 : * @j_reserved_credits:
1013 : *
1014 : * Number of buffers reserved from the running transaction.
1015 : */
1016 : atomic_t j_reserved_credits;
1017 :
1018 : /**
1019 : * @j_list_lock: Protects the buffer lists and internal buffer state.
1020 : */
1021 : spinlock_t j_list_lock;
1022 :
1023 : /**
1024 : * @j_inode:
1025 : *
1026 : * Optional inode where we store the journal. If present, all
1027 : * journal block numbers are mapped into this inode via bmap().
1028 : */
1029 : struct inode *j_inode;
1030 :
1031 : /**
1032 : * @j_tail_sequence:
1033 : *
1034 : * Sequence number of the oldest transaction in the log [j_state_lock]
1035 : */
1036 : tid_t j_tail_sequence;
1037 :
1038 : /**
1039 : * @j_transaction_sequence:
1040 : *
1041 : * Sequence number of the next transaction to grant [j_state_lock]
1042 : */
1043 : tid_t j_transaction_sequence;
1044 :
1045 : /**
1046 : * @j_commit_sequence:
1047 : *
1048 : * Sequence number of the most recently committed transaction
1049 : * [j_state_lock, no lock for quick racy checks]
1050 : */
1051 : tid_t j_commit_sequence;
1052 :
1053 : /**
1054 : * @j_commit_request:
1055 : *
1056 : * Sequence number of the most recent transaction wanting commit
1057 : * [j_state_lock, no lock for quick racy checks]
1058 : */
1059 : tid_t j_commit_request;
1060 :
1061 : /**
1062 : * @j_uuid:
1063 : *
1064 : * Journal uuid: identifies the object (filesystem, LVM volume etc)
1065 : * backed by this journal. This will eventually be replaced by an array
1066 : * of uuids, allowing us to index multiple devices within a single
1067 : * journal and to perform atomic updates across them.
1068 : */
1069 : __u8 j_uuid[16];
1070 :
1071 : /**
1072 : * @j_task: Pointer to the current commit thread for this journal.
1073 : */
1074 : struct task_struct *j_task;
1075 :
1076 : /**
1077 : * @j_max_transaction_buffers:
1078 : *
1079 : * Maximum number of metadata buffers to allow in a single compound
1080 : * commit transaction.
1081 : */
1082 : int j_max_transaction_buffers;
1083 :
1084 : /**
1085 : * @j_revoke_records_per_block:
1086 : *
1087 : * Number of revoke records that fit in one descriptor block.
1088 : */
1089 : int j_revoke_records_per_block;
1090 :
1091 : /**
1092 : * @j_commit_interval:
1093 : *
1094 : * What is the maximum transaction lifetime before we begin a commit?
1095 : */
1096 : unsigned long j_commit_interval;
1097 :
1098 : /**
1099 : * @j_commit_timer: The timer used to wakeup the commit thread.
1100 : */
1101 : struct timer_list j_commit_timer;
1102 :
1103 : /**
1104 : * @j_revoke_lock: Protect the revoke table.
1105 : */
1106 : spinlock_t j_revoke_lock;
1107 :
1108 : /**
1109 : * @j_revoke:
1110 : *
1111 : * The revoke table - maintains the list of revoked blocks in the
1112 : * current transaction.
1113 : */
1114 : struct jbd2_revoke_table_s *j_revoke;
1115 :
1116 : /**
1117 : * @j_revoke_table: Alternate revoke tables for j_revoke.
1118 : */
1119 : struct jbd2_revoke_table_s *j_revoke_table[2];
1120 :
1121 : /**
1122 : * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
1123 : */
1124 : struct buffer_head **j_wbuf;
1125 :
1126 : /**
1127 : * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
1128 : * during a fast commit. Currently only process can do fast commit, so
1129 : * this field is not protected by any lock.
1130 : */
1131 : struct buffer_head **j_fc_wbuf;
1132 :
1133 : /**
1134 : * @j_wbufsize:
1135 : *
1136 : * Size of @j_wbuf array.
1137 : */
1138 : int j_wbufsize;
1139 :
1140 : /**
1141 : * @j_fc_wbufsize:
1142 : *
1143 : * Size of @j_fc_wbuf array.
1144 : */
1145 : int j_fc_wbufsize;
1146 :
1147 : /**
1148 : * @j_last_sync_writer:
1149 : *
1150 : * The pid of the last person to run a synchronous operation
1151 : * through the journal.
1152 : */
1153 : pid_t j_last_sync_writer;
1154 :
1155 : /**
1156 : * @j_average_commit_time:
1157 : *
1158 : * The average amount of time in nanoseconds it takes to commit a
1159 : * transaction to disk. [j_state_lock]
1160 : */
1161 : u64 j_average_commit_time;
1162 :
1163 : /**
1164 : * @j_min_batch_time:
1165 : *
1166 : * Minimum time that we should wait for additional filesystem operations
1167 : * to get batched into a synchronous handle in microseconds.
1168 : */
1169 : u32 j_min_batch_time;
1170 :
1171 : /**
1172 : * @j_max_batch_time:
1173 : *
1174 : * Maximum time that we should wait for additional filesystem operations
1175 : * to get batched into a synchronous handle in microseconds.
1176 : */
1177 : u32 j_max_batch_time;
1178 :
1179 : /**
1180 : * @j_commit_callback:
1181 : *
1182 : * This function is called when a transaction is closed.
1183 : */
1184 : void (*j_commit_callback)(journal_t *,
1185 : transaction_t *);
1186 :
1187 : /**
1188 : * @j_submit_inode_data_buffers:
1189 : *
1190 : * This function is called for all inodes associated with the
1191 : * committing transaction marked with JI_WRITE_DATA flag
1192 : * before we start to write out the transaction to the journal.
1193 : */
1194 : int (*j_submit_inode_data_buffers)
1195 : (struct jbd2_inode *);
1196 :
1197 : /**
1198 : * @j_finish_inode_data_buffers:
1199 : *
1200 : * This function is called for all inodes associated with the
1201 : * committing transaction marked with JI_WAIT_DATA flag
1202 : * after we have written the transaction to the journal
1203 : * but before we write out the commit block.
1204 : */
1205 : int (*j_finish_inode_data_buffers)
1206 : (struct jbd2_inode *);
1207 :
1208 : /*
1209 : * Journal statistics
1210 : */
1211 :
1212 : /**
1213 : * @j_history_lock: Protect the transactions statistics history.
1214 : */
1215 : spinlock_t j_history_lock;
1216 :
1217 : /**
1218 : * @j_proc_entry: procfs entry for the jbd statistics directory.
1219 : */
1220 : struct proc_dir_entry *j_proc_entry;
1221 :
1222 : /**
1223 : * @j_stats: Overall statistics.
1224 : */
1225 : struct transaction_stats_s j_stats;
1226 :
1227 : /**
1228 : * @j_failed_commit: Failed journal commit ID.
1229 : */
1230 : unsigned int j_failed_commit;
1231 :
1232 : /**
1233 : * @j_private:
1234 : *
1235 : * An opaque pointer to fs-private information. ext3 puts its
1236 : * superblock pointer here.
1237 : */
1238 : void *j_private;
1239 :
1240 : /**
1241 : * @j_chksum_driver:
1242 : *
1243 : * Reference to checksum algorithm driver via cryptoapi.
1244 : */
1245 : struct crypto_shash *j_chksum_driver;
1246 :
1247 : /**
1248 : * @j_csum_seed:
1249 : *
1250 : * Precomputed journal UUID checksum for seeding other checksums.
1251 : */
1252 : __u32 j_csum_seed;
1253 :
1254 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
1255 : /**
1256 : * @j_trans_commit_map:
1257 : *
1258 : * Lockdep entity to track transaction commit dependencies. Handles
1259 : * hold this "lock" for read, when we wait for commit, we acquire the
1260 : * "lock" for writing. This matches the properties of jbd2 journalling
1261 : * where the running transaction has to wait for all handles to be
1262 : * dropped to commit that transaction and also acquiring a handle may
1263 : * require transaction commit to finish.
1264 : */
1265 : struct lockdep_map j_trans_commit_map;
1266 : #endif
1267 :
1268 : /**
1269 : * @j_fc_cleanup_callback:
1270 : *
1271 : * Clean-up after fast commit or full commit. JBD2 calls this function
1272 : * after every commit operation.
1273 : */
1274 : void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
1275 :
1276 : /**
1277 : * @j_fc_replay_callback:
1278 : *
1279 : * File-system specific function that performs replay of a fast
1280 : * commit. JBD2 calls this function for each fast commit block found in
1281 : * the journal. This function should return JBD2_FC_REPLAY_CONTINUE
1282 : * to indicate that the block was processed correctly and more fast
1283 : * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP
1284 : * indicates the end of replay (no more blocks remaining). A negative
1285 : * return value indicates error.
1286 : */
1287 : int (*j_fc_replay_callback)(struct journal_s *journal,
1288 : struct buffer_head *bh,
1289 : enum passtype pass, int off,
1290 : tid_t expected_commit_id);
1291 :
1292 : /**
1293 : * @j_bmap:
1294 : *
1295 : * Bmap function that should be used instead of the generic
1296 : * VFS bmap function.
1297 : */
1298 : int (*j_bmap)(struct journal_s *journal, sector_t *block);
1299 : };
1300 :
1301 : #define jbd2_might_wait_for_commit(j) \
1302 : do { \
1303 : rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
1304 : rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
1305 : } while (0)
1306 :
1307 : /*
1308 : * We can support any known requested features iff the
1309 : * superblock is not in version 1. Otherwise we fail to support any
1310 : * extended sb features.
1311 : */
1312 : static inline bool jbd2_format_support_feature(journal_t *j)
1313 : {
1314 0 : return j->j_superblock->s_header.h_blocktype !=
1315 : cpu_to_be32(JBD2_SUPERBLOCK_V1);
1316 : }
1317 :
1318 : /* journal feature predicate functions */
1319 : #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1320 : static inline bool jbd2_has_feature_##name(journal_t *j) \
1321 : { \
1322 : return (jbd2_format_support_feature(j) && \
1323 : ((j)->j_superblock->s_feature_compat & \
1324 : cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1325 : } \
1326 : static inline void jbd2_set_feature_##name(journal_t *j) \
1327 : { \
1328 : (j)->j_superblock->s_feature_compat |= \
1329 : cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1330 : } \
1331 : static inline void jbd2_clear_feature_##name(journal_t *j) \
1332 : { \
1333 : (j)->j_superblock->s_feature_compat &= \
1334 : ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1335 : }
1336 :
1337 : #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1338 : static inline bool jbd2_has_feature_##name(journal_t *j) \
1339 : { \
1340 : return (jbd2_format_support_feature(j) && \
1341 : ((j)->j_superblock->s_feature_ro_compat & \
1342 : cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1343 : } \
1344 : static inline void jbd2_set_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 : static inline void jbd2_clear_feature_##name(journal_t *j) \
1350 : { \
1351 : (j)->j_superblock->s_feature_ro_compat &= \
1352 : ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1353 : }
1354 :
1355 : #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1356 : static inline bool jbd2_has_feature_##name(journal_t *j) \
1357 : { \
1358 : return (jbd2_format_support_feature(j) && \
1359 : ((j)->j_superblock->s_feature_incompat & \
1360 : cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1361 : } \
1362 : static inline void jbd2_set_feature_##name(journal_t *j) \
1363 : { \
1364 : (j)->j_superblock->s_feature_incompat |= \
1365 : cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1366 : } \
1367 : static inline void jbd2_clear_feature_##name(journal_t *j) \
1368 : { \
1369 : (j)->j_superblock->s_feature_incompat &= \
1370 : ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1371 : }
1372 :
1373 0 : JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
1374 :
1375 : JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
1376 0 : JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
1377 0 : JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
1378 0 : JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
1379 0 : JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
1380 0 : JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT)
1381 :
1382 : /*
1383 : * Journal flag definitions
1384 : */
1385 : #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1386 : #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1387 : #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1388 : #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1389 : #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1390 : #define JBD2_BARRIER 0x020 /* Use IDE barriers */
1391 : #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
1392 : * data write error in ordered
1393 : * mode */
1394 : #define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on
1395 : * clean and empty filesystem
1396 : * logging area */
1397 : #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */
1398 : #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
1399 : #define JBD2_JOURNAL_FLUSH_DISCARD 0x0001
1400 : #define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002
1401 : #define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \
1402 : JBD2_JOURNAL_FLUSH_ZEROOUT)
1403 :
1404 : /*
1405 : * Journal atomic flag definitions
1406 : */
1407 : #define JBD2_CHECKPOINT_IO_ERROR 0x001 /* Detect io error while writing
1408 : * buffer back to disk */
1409 :
1410 : /*
1411 : * Function declarations for the journaling transaction and buffer
1412 : * management
1413 : */
1414 :
1415 : /* Filing buffers */
1416 : extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
1417 : extern bool __jbd2_journal_refile_buffer(struct journal_head *);
1418 : extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1419 : extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1420 : extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1421 : static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1422 : {
1423 0 : list_add_tail(&bh->b_assoc_buffers, head);
1424 0 : }
1425 : static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1426 : {
1427 0 : list_del_init(&bh->b_assoc_buffers);
1428 : }
1429 :
1430 : /* Log buffer allocation */
1431 : struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
1432 : void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
1433 : int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1434 : int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1435 : unsigned long *block);
1436 : int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1437 : void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1438 :
1439 : /* Commit management */
1440 : extern void jbd2_journal_commit_transaction(journal_t *);
1441 :
1442 : /* Checkpoint list management */
1443 : void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
1444 : unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
1445 : int __jbd2_journal_remove_checkpoint(struct journal_head *);
1446 : int jbd2_journal_try_remove_checkpoint(struct journal_head *jh);
1447 : void jbd2_journal_destroy_checkpoint(journal_t *journal);
1448 : void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1449 :
1450 :
1451 : /*
1452 : * Triggers
1453 : */
1454 :
1455 : struct jbd2_buffer_trigger_type {
1456 : /*
1457 : * Fired a the moment data to write to the journal are known to be
1458 : * stable - so either at the moment b_frozen_data is created or just
1459 : * before a buffer is written to the journal. mapped_data is a mapped
1460 : * buffer that is the frozen data for commit.
1461 : */
1462 : void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1463 : struct buffer_head *bh, void *mapped_data,
1464 : size_t size);
1465 :
1466 : /*
1467 : * Fired during journal abort for dirty buffers that will not be
1468 : * committed.
1469 : */
1470 : void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1471 : struct buffer_head *bh);
1472 : };
1473 :
1474 : extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1475 : void *mapped_data,
1476 : struct jbd2_buffer_trigger_type *triggers);
1477 : extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1478 : struct jbd2_buffer_trigger_type *triggers);
1479 :
1480 : /* Buffer IO */
1481 : extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1482 : struct journal_head *jh_in,
1483 : struct buffer_head **bh_out,
1484 : sector_t blocknr);
1485 :
1486 : /* Transaction cache support */
1487 : extern void jbd2_journal_destroy_transaction_cache(void);
1488 : extern int __init jbd2_journal_init_transaction_cache(void);
1489 : extern void jbd2_journal_free_transaction(transaction_t *);
1490 :
1491 : /*
1492 : * Journal locking.
1493 : *
1494 : * We need to lock the journal during transaction state changes so that nobody
1495 : * ever tries to take a handle on the running transaction while we are in the
1496 : * middle of moving it to the commit phase. j_state_lock does this.
1497 : *
1498 : * Note that the locking is completely interrupt unsafe. We never touch
1499 : * journal structures from interrupts.
1500 : */
1501 :
1502 : static inline handle_t *journal_current_handle(void)
1503 : {
1504 0 : return current->journal_info;
1505 : }
1506 :
1507 : /* The journaling code user interface:
1508 : *
1509 : * Create and destroy handles
1510 : * Register buffer modifications against the current transaction.
1511 : */
1512 :
1513 : extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1514 : extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1515 : int revoke_records, gfp_t gfp_mask,
1516 : unsigned int type, unsigned int line_no);
1517 : extern int jbd2_journal_restart(handle_t *, int nblocks);
1518 : extern int jbd2__journal_restart(handle_t *, int nblocks,
1519 : int revoke_records, gfp_t gfp_mask);
1520 : extern int jbd2_journal_start_reserved(handle_t *handle,
1521 : unsigned int type, unsigned int line_no);
1522 : extern void jbd2_journal_free_reserved(handle_t *handle);
1523 : extern int jbd2_journal_extend(handle_t *handle, int nblocks,
1524 : int revoke_records);
1525 : extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1526 : extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1527 : extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1528 : void jbd2_journal_set_triggers(struct buffer_head *,
1529 : struct jbd2_buffer_trigger_type *type);
1530 : extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1531 : extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1532 : int jbd2_journal_invalidate_folio(journal_t *, struct folio *,
1533 : size_t offset, size_t length);
1534 : bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio);
1535 : extern int jbd2_journal_stop(handle_t *);
1536 : extern int jbd2_journal_flush(journal_t *journal, unsigned int flags);
1537 : extern void jbd2_journal_lock_updates (journal_t *);
1538 : extern void jbd2_journal_unlock_updates (journal_t *);
1539 :
1540 : void jbd2_journal_wait_updates(journal_t *);
1541 :
1542 : extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1543 : struct block_device *fs_dev,
1544 : unsigned long long start, int len, int bsize);
1545 : extern journal_t * jbd2_journal_init_inode (struct inode *);
1546 : extern int jbd2_journal_update_format (journal_t *);
1547 : extern int jbd2_journal_check_used_features
1548 : (journal_t *, unsigned long, unsigned long, unsigned long);
1549 : extern int jbd2_journal_check_available_features
1550 : (journal_t *, unsigned long, unsigned long, unsigned long);
1551 : extern int jbd2_journal_set_features
1552 : (journal_t *, unsigned long, unsigned long, unsigned long);
1553 : extern void jbd2_journal_clear_features
1554 : (journal_t *, unsigned long, unsigned long, unsigned long);
1555 : extern int jbd2_journal_load (journal_t *journal);
1556 : extern int jbd2_journal_destroy (journal_t *);
1557 : extern int jbd2_journal_recover (journal_t *journal);
1558 : extern int jbd2_journal_wipe (journal_t *, int);
1559 : extern int jbd2_journal_skip_recovery (journal_t *);
1560 : extern void jbd2_journal_update_sb_errno(journal_t *);
1561 : extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t,
1562 : unsigned long, blk_opf_t);
1563 : extern void jbd2_journal_abort (journal_t *, int);
1564 : extern int jbd2_journal_errno (journal_t *);
1565 : extern void jbd2_journal_ack_err (journal_t *);
1566 : extern int jbd2_journal_clear_err (journal_t *);
1567 : extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1568 : extern int jbd2_journal_force_commit(journal_t *);
1569 : extern int jbd2_journal_force_commit_nested(journal_t *);
1570 : extern int jbd2_journal_inode_ranged_write(handle_t *handle,
1571 : struct jbd2_inode *inode, loff_t start_byte,
1572 : loff_t length);
1573 : extern int jbd2_journal_inode_ranged_wait(handle_t *handle,
1574 : struct jbd2_inode *inode, loff_t start_byte,
1575 : loff_t length);
1576 : extern int jbd2_journal_finish_inode_data_buffers(
1577 : struct jbd2_inode *jinode);
1578 : extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
1579 : struct jbd2_inode *inode, loff_t new_size);
1580 : extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1581 : extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1582 :
1583 : /*
1584 : * journal_head management
1585 : */
1586 : struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1587 : struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1588 : void jbd2_journal_put_journal_head(struct journal_head *jh);
1589 :
1590 : /*
1591 : * handle management
1592 : */
1593 : extern struct kmem_cache *jbd2_handle_cache;
1594 :
1595 : static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1596 : {
1597 0 : return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags);
1598 : }
1599 :
1600 : static inline void jbd2_free_handle(handle_t *handle)
1601 : {
1602 0 : kmem_cache_free(jbd2_handle_cache, handle);
1603 0 : }
1604 :
1605 : /*
1606 : * jbd2_inode management (optional, for those file systems that want to use
1607 : * dynamically allocated jbd2_inode structures)
1608 : */
1609 : extern struct kmem_cache *jbd2_inode_cache;
1610 :
1611 : static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1612 : {
1613 0 : return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
1614 : }
1615 :
1616 : static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1617 : {
1618 0 : kmem_cache_free(jbd2_inode_cache, jinode);
1619 0 : }
1620 :
1621 : /* Primary revoke support */
1622 : #define JOURNAL_REVOKE_DEFAULT_HASH 256
1623 : extern int jbd2_journal_init_revoke(journal_t *, int);
1624 : extern void jbd2_journal_destroy_revoke_record_cache(void);
1625 : extern void jbd2_journal_destroy_revoke_table_cache(void);
1626 : extern int __init jbd2_journal_init_revoke_record_cache(void);
1627 : extern int __init jbd2_journal_init_revoke_table_cache(void);
1628 :
1629 : extern void jbd2_journal_destroy_revoke(journal_t *);
1630 : extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1631 : extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1632 : extern void jbd2_journal_write_revoke_records(transaction_t *transaction,
1633 : struct list_head *log_bufs);
1634 :
1635 : /* Recovery revoke support */
1636 : extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1637 : extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1638 : extern void jbd2_journal_clear_revoke(journal_t *);
1639 : extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1640 : extern void jbd2_clear_buffer_revoked_flags(journal_t *journal);
1641 :
1642 : /*
1643 : * The log thread user interface:
1644 : *
1645 : * Request space in the current transaction, and force transaction commit
1646 : * transitions on demand.
1647 : */
1648 :
1649 : int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1650 : int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1651 : int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1652 : int jbd2_transaction_committed(journal_t *journal, tid_t tid);
1653 : int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1654 : int jbd2_log_do_checkpoint(journal_t *journal);
1655 : int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1656 :
1657 : void __jbd2_log_wait_for_space(journal_t *journal);
1658 : extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1659 : extern int jbd2_cleanup_journal_tail(journal_t *);
1660 :
1661 : /* Fast commit related APIs */
1662 : int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
1663 : int jbd2_fc_end_commit(journal_t *journal);
1664 : int jbd2_fc_end_commit_fallback(journal_t *journal);
1665 : int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
1666 : int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1667 : int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1668 : int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
1669 : int jbd2_fc_release_bufs(journal_t *journal);
1670 :
1671 : static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal)
1672 : {
1673 0 : return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
1674 : }
1675 :
1676 : /*
1677 : * is_journal_abort
1678 : *
1679 : * Simple test wrapper function to test the JBD2_ABORT state flag. This
1680 : * bit, when set, indicates that we have had a fatal error somewhere,
1681 : * either inside the journaling layer or indicated to us by the client
1682 : * (eg. ext3), and that we and should not commit any further
1683 : * transactions.
1684 : */
1685 :
1686 : static inline int is_journal_aborted(journal_t *journal)
1687 : {
1688 0 : return journal->j_flags & JBD2_ABORT;
1689 : }
1690 :
1691 : static inline int is_handle_aborted(handle_t *handle)
1692 : {
1693 0 : if (handle->h_aborted || !handle->h_transaction)
1694 : return 1;
1695 0 : return is_journal_aborted(handle->h_transaction->t_journal);
1696 : }
1697 :
1698 : static inline void jbd2_journal_abort_handle(handle_t *handle)
1699 : {
1700 0 : handle->h_aborted = 1;
1701 : }
1702 :
1703 : #endif /* __KERNEL__ */
1704 :
1705 : /* Comparison functions for transaction IDs: perform comparisons using
1706 : * modulo arithmetic so that they work over sequence number wraps. */
1707 :
1708 : static inline int tid_gt(tid_t x, tid_t y)
1709 : {
1710 0 : int difference = (x - y);
1711 0 : return (difference > 0);
1712 : }
1713 :
1714 : static inline int tid_geq(tid_t x, tid_t y)
1715 : {
1716 0 : int difference = (x - y);
1717 0 : return (difference >= 0);
1718 : }
1719 :
1720 : extern int jbd2_journal_blocks_per_page(struct inode *inode);
1721 : extern size_t journal_tag_bytes(journal_t *journal);
1722 :
1723 0 : static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
1724 : {
1725 0 : return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j);
1726 : }
1727 :
1728 0 : static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1729 : {
1730 0 : WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) &&
1731 : journal->j_chksum_driver == NULL);
1732 :
1733 0 : return journal->j_chksum_driver != NULL;
1734 : }
1735 :
1736 0 : static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb)
1737 : {
1738 0 : int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks);
1739 :
1740 0 : return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS;
1741 : }
1742 :
1743 : /*
1744 : * Return number of free blocks in the log. Must be called under j_state_lock.
1745 : */
1746 : static inline unsigned long jbd2_log_space_left(journal_t *journal)
1747 : {
1748 : /* Allow for rounding errors */
1749 0 : long free = journal->j_free - 32;
1750 :
1751 0 : if (journal->j_committing_transaction) {
1752 0 : free -= atomic_read(&journal->
1753 : j_committing_transaction->t_outstanding_credits);
1754 : }
1755 0 : return max_t(long, free, 0);
1756 : }
1757 :
1758 : /*
1759 : * Definitions which augment the buffer_head layer
1760 : */
1761 :
1762 : /* journaling buffer types */
1763 : #define BJ_None 0 /* Not journaled */
1764 : #define BJ_Metadata 1 /* Normal journaled metadata */
1765 : #define BJ_Forget 2 /* Buffer superseded by this transaction */
1766 : #define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1767 : #define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1768 : #define BJ_Types 5
1769 :
1770 : /* JBD uses a CRC32 checksum */
1771 : #define JBD_MAX_CHECKSUM_SIZE 4
1772 :
1773 0 : static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
1774 : const void *address, unsigned int length)
1775 : {
1776 0 : struct {
1777 : struct shash_desc shash;
1778 : char ctx[JBD_MAX_CHECKSUM_SIZE];
1779 : } desc;
1780 0 : int err;
1781 :
1782 0 : BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
1783 : JBD_MAX_CHECKSUM_SIZE);
1784 :
1785 0 : desc.shash.tfm = journal->j_chksum_driver;
1786 0 : *(u32 *)desc.ctx = crc;
1787 :
1788 0 : err = crypto_shash_update(&desc.shash, address, length);
1789 0 : BUG_ON(err);
1790 :
1791 0 : return *(u32 *)desc.ctx;
1792 : }
1793 :
1794 : /* Return most recent uncommitted transaction */
1795 0 : static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
1796 : {
1797 0 : tid_t tid;
1798 :
1799 0 : read_lock(&journal->j_state_lock);
1800 0 : tid = journal->j_commit_request;
1801 0 : if (journal->j_running_transaction)
1802 0 : tid = journal->j_running_transaction->t_tid;
1803 0 : read_unlock(&journal->j_state_lock);
1804 0 : return tid;
1805 : }
1806 :
1807 0 : static inline int jbd2_handle_buffer_credits(handle_t *handle)
1808 : {
1809 0 : journal_t *journal;
1810 :
1811 0 : if (!handle->h_reserved)
1812 0 : journal = handle->h_transaction->t_journal;
1813 : else
1814 0 : journal = handle->h_journal;
1815 :
1816 0 : return handle->h_total_credits -
1817 0 : DIV_ROUND_UP(handle->h_revoke_credits_requested,
1818 : journal->j_revoke_records_per_block);
1819 : }
1820 :
1821 : #ifdef __KERNEL__
1822 :
1823 : #define buffer_trace_init(bh) do {} while (0)
1824 : #define print_buffer_fields(bh) do {} while (0)
1825 : #define print_buffer_trace(bh) do {} while (0)
1826 : #define BUFFER_TRACE(bh, info) do {} while (0)
1827 : #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1828 : #define JBUFFER_TRACE(jh, info) do {} while (0)
1829 :
1830 : #endif /* __KERNEL__ */
1831 :
1832 : #define EFSBADCRC EBADMSG /* Bad CRC detected */
1833 : #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
1834 :
1835 : #endif /* _LINUX_JBD2_H */
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