1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * linux/include/linux/jbd2.h
5 * Written by Stephen C. Tweedie <sct@redhat.com>
7 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
9 * Definitions for transaction data structures for the buffer cache
10 * filesystem journaling support.
16 /* Allow this file to be included directly into e2fsprogs */
18 #include "jfs_compat.h"
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>
34 #define journal_oom_retry 1
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.
43 #undef JBD2_PARANOID_IOFAIL
46 * The default maximum commit age, in seconds.
48 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
50 #ifdef CONFIG_JBD2_DEBUG
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.
56 #define JBD2_EXPENSIVE_CHECKING
57 void __jbd2_debug(int level, const char *file, const char *func,
58 unsigned int line, const char *fmt, ...);
60 #define jbd2_debug(n, fmt, a...) \
61 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
63 #define jbd2_debug(n, fmt, a...) no_printk(fmt, ##a)
66 extern void *jbd2_alloc(size_t size, gfp_t flags);
67 extern void jbd2_free(void *ptr, size_t size);
69 #define JBD2_MIN_JOURNAL_BLOCKS 1024
70 #define JBD2_DEFAULT_FAST_COMMIT_BLOCKS 256
75 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
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.
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.
89 * This is an opaque datatype.
91 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */
95 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
97 * journal_t is linked to from the fs superblock structure.
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
103 * This is an opaque datatype.
105 typedef struct journal_s journal_t; /* Journal control structure */
109 * Internal structures used by the logging mechanism:
112 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
119 * Descriptor block types:
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
129 * Standard header for all descriptor blocks:
131 typedef struct journal_header_s
141 #define JBD2_CRC32_CHKSUM 1
142 #define JBD2_MD5_CHKSUM 2
143 #define JBD2_SHA1_CHKSUM 3
144 #define JBD2_CRC32C_CHKSUM 4
146 #define JBD2_CRC32_CHKSUM_SIZE 4
148 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
150 * Commit block header for storing transactional checksums:
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.
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
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
165 * Checksum v1, v2, and v3 are mutually exclusive features.
167 struct commit_header {
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];
176 __be32 h_commit_nsec;
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.
185 typedef struct journal_block_tag3_s
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;
193 typedef struct journal_block_tag_s
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;
201 /* Tail of descriptor or revoke block, for checksumming */
202 struct jbd2_journal_block_tail {
203 __be32 t_checksum; /* crc32c(uuid+descr_block) */
207 * The revoke descriptor: used on disk to describe a series of blocks to
208 * be revoked from the log
210 typedef struct jbd2_journal_revoke_header_s
212 journal_header_t r_header;
213 __be32 r_count; /* Count of bytes used in the block */
214 } jbd2_journal_revoke_header_t;
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 */
224 * The journal superblock. All fields are in big-endian byte order.
226 typedef struct journal_superblock_s
229 journal_header_t s_header;
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 */
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 */
243 /* Error value, as set by jbd2_journal_abort(). */
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 */
252 __u8 s_uuid[16]; /* 128-bit uuid for journal */
255 __be32 s_nr_users; /* Nr of filesystems sharing log */
257 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
260 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
261 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
264 __u8 s_checksum_type; /* checksum type */
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 */
272 __be32 s_checksum; /* crc32c(superblock) */
275 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
277 } journal_superblock_t;
279 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001
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
288 /* See "journal feature predicate functions" below */
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)
302 #include <linux/fs.h>
303 #include <linux/sched.h>
305 enum jbd_state_bits {
306 BH_JBD /* Has an attached ext3 journal_head */
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 */
320 BUFFER_FNS(JWrite, jwrite)
321 BUFFER_FNS(JBDDirty, jbddirty)
322 TAS_BUFFER_FNS(JBDDirty, jbddirty)
323 BUFFER_FNS(Revoked, revoked)
324 TAS_BUFFER_FNS(Revoked, revoked)
325 BUFFER_FNS(RevokeValid, revokevalid)
326 TAS_BUFFER_FNS(RevokeValid, revokevalid)
327 BUFFER_FNS(Freed, freed)
328 BUFFER_FNS(Shadow, shadow)
329 BUFFER_FNS(Verified, verified)
331 static inline struct buffer_head *jh2bh(struct journal_head *jh)
336 static inline struct journal_head *bh2jh(struct buffer_head *bh)
338 return bh->b_private;
341 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
343 bit_spin_lock(BH_JournalHead, &bh->b_state);
346 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
348 bit_spin_unlock(BH_JournalHead, &bh->b_state);
351 #define J_ASSERT(assert) BUG_ON(!(assert))
353 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
354 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
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)
361 #define __journal_expect(expr, why...) \
366 "JBD2 unexpected failure: %s: %s;\n", \
368 printk(KERN_ERR why "\n"); \
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)
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
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
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)
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.
401 * Which transaction does this inode belong to? Either the running
402 * transaction or the committing one. [j_list_lock]
404 transaction_t *i_transaction;
407 * @i_next_transaction:
409 * Pointer to the running transaction modifying inode's data in case
410 * there is already a committing transaction touching it. [j_list_lock]
412 transaction_t *i_next_transaction;
415 * @i_list: List of inodes in the i_transaction [j_list_lock]
417 struct list_head i_list;
422 * VFS inode this inode belongs to [constant for lifetime of structure]
424 struct inode *i_vfs_inode;
427 * @i_flags: Flags of inode [j_list_lock]
429 unsigned long i_flags;
434 * Offset in bytes where the dirty range for this inode starts.
437 loff_t i_dirty_start;
442 * Inclusive offset in bytes where the dirty range for this inode
443 * ends. [j_list_lock]
448 struct jbd2_revoke_table_s;
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.
473 /* Docbook can't yet cope with the bit fields, but will leave the documentation
474 * in so it can be fixed later.
477 struct jbd2_journal_handle
480 transaction_t *h_transaction;
481 /* Which journal handle belongs to - used iff h_reserved set */
482 journal_t *h_journal;
485 handle_t *h_rsv_handle;
487 int h_revoke_credits;
488 int h_revoke_credits_requested;
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;
500 unsigned long h_start_jiffies;
501 unsigned int h_requested_credits;
503 unsigned int saved_alloc_context;
508 * Some stats for checkpoint phase
510 struct transaction_chp_stats_s {
511 unsigned long cs_chp_time;
512 __u32 cs_forced_to_close;
517 /* The transaction_t type is the guts of the journaling mechanism. It
518 * tracks a compound transaction through its various states:
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.
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)
538 * ->jbd_lock_bh_journal_head() (This is "innermost")
547 * ->j_list_lock (journal_unmap_buffer)
553 /* Pointer to the journal for this transaction. [no locking] */
554 journal_t *t_journal;
556 /* Sequence number for this transaction [no locking] */
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]
580 * Where in the log does this transaction's commit start? [no locking]
582 unsigned long t_log_start;
585 * Number of buffers on the t_buffers list [j_list_lock, no locks
586 * needed for jbd2 thread]
591 * Doubly-linked circular list of all buffers reserved but not yet
592 * modified by this transaction [j_list_lock, no locks needed fo
595 struct journal_head *t_reserved_list;
598 * Doubly-linked circular list of all metadata buffers owned by this
599 * transaction [j_list_lock, no locks needed for jbd2 thread]
601 struct journal_head *t_buffers;
604 * Doubly-linked circular list of all forget buffers (superseded
605 * buffers which we can un-checkpoint once this transaction commits)
608 struct journal_head *t_forget;
611 * Doubly-linked circular list of all buffers still to be flushed before
612 * this transaction can be checkpointed. [j_list_lock]
614 struct journal_head *t_checkpoint_list;
617 * Doubly-linked circular list of all buffers submitted for IO while
618 * checkpointing. [j_list_lock]
620 struct journal_head *t_checkpoint_io_list;
623 * Doubly-linked circular list of metadata buffers being
624 * shadowed by log IO. The IO buffers on the iobuf list and
625 * the shadow buffers on this list match each other one for
626 * one at all times. [j_list_lock, no locks needed for jbd2
629 struct journal_head *t_shadow_list;
632 * List of inodes associated with the transaction; e.g., ext4 uses
633 * this to track inodes in data=ordered and data=journal mode that
634 * need special handling on transaction commit; also used by ocfs2.
637 struct list_head t_inode_list;
640 * Protects info related to handles
642 spinlock_t t_handle_lock;
645 * Longest time some handle had to wait for running transaction
647 unsigned long t_max_wait;
650 * When transaction started
652 unsigned long t_start;
655 * When commit was requested [j_state_lock]
657 unsigned long t_requested;
660 * Checkpointing stats [j_list_lock]
662 struct transaction_chp_stats_s t_chp_stats;
665 * Number of outstanding updates running on this transaction
671 * Number of blocks reserved for this transaction in the journal.
672 * This is including all credits reserved when starting transaction
673 * handles as well as all journal descriptor blocks needed for this
674 * transaction. [none]
676 atomic_t t_outstanding_credits;
679 * Number of revoke records for this transaction added by already
680 * stopped handles. [none]
682 atomic_t t_outstanding_revokes;
685 * How many handles used this transaction? [none]
687 atomic_t t_handle_count;
690 * Forward and backward links for the circular list of all transactions
691 * awaiting checkpoint. [j_list_lock]
693 transaction_t *t_cpnext, *t_cpprev;
696 * When will the transaction expire (become due for commit), in jiffies?
699 unsigned long t_expires;
702 * When this transaction started, in nanoseconds [no locking]
704 ktime_t t_start_time;
707 * This transaction is being forced and some process is
708 * waiting for it to finish.
710 unsigned int t_synchronous_commit:1;
712 /* Disk flush needs to be sent to fs partition [no locking] */
713 int t_need_data_flush;
716 * For use by the filesystem to store fs-specific data
717 * structures associated with the transaction
719 struct list_head t_private_list;
722 struct transaction_run_stats_s {
723 unsigned long rs_wait;
724 unsigned long rs_request_delay;
725 unsigned long rs_running;
726 unsigned long rs_locked;
727 unsigned long rs_flushing;
728 unsigned long rs_logging;
730 __u32 rs_handle_count;
732 __u32 rs_blocks_logged;
735 struct transaction_stats_s {
736 unsigned long ts_tid;
737 unsigned long ts_requested;
738 struct transaction_run_stats_s run;
741 static inline unsigned long
742 jbd2_time_diff(unsigned long start, unsigned long end)
747 return end + (MAX_JIFFY_OFFSET - start);
750 #define JBD2_NR_BATCH 64
752 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
754 #define JBD2_FC_REPLAY_STOP 0
755 #define JBD2_FC_REPLAY_CONTINUE 1
758 * struct journal_s - The journal_s type is the concrete type associated with
764 * @j_flags: General journaling state flags [j_state_lock,
765 * no lock for quick racy checks]
767 unsigned long j_flags;
770 * @j_atomic_flags: Atomic journaling state flags.
772 unsigned long j_atomic_flags;
777 * Is there an outstanding uncleared error on the journal (from a prior
778 * abort)? [j_state_lock]
783 * @j_abort_mutex: Lock the whole aborting procedure.
785 struct mutex j_abort_mutex;
788 * @j_sb_buffer: The first part of the superblock buffer.
790 struct buffer_head *j_sb_buffer;
793 * @j_superblock: The second part of the superblock buffer.
795 journal_superblock_t *j_superblock;
798 * @j_state_lock: Protect the various scalars in the journal.
800 rwlock_t j_state_lock;
805 * Number of processes waiting to create a barrier lock [j_state_lock,
806 * no lock for quick racy checks]
811 * @j_barrier: The barrier lock itself.
813 struct mutex j_barrier;
816 * @j_running_transaction:
818 * Transactions: The current running transaction...
819 * [j_state_lock, no lock for quick racy checks] [caller holding
822 transaction_t *j_running_transaction;
825 * @j_committing_transaction:
827 * the transaction we are pushing to disk
828 * [j_state_lock] [caller holding open handle]
830 transaction_t *j_committing_transaction;
833 * @j_checkpoint_transactions:
835 * ... and a linked circular list of all transactions waiting for
836 * checkpointing. [j_list_lock]
838 transaction_t *j_checkpoint_transactions;
841 * @j_wait_transaction_locked:
843 * Wait queue for waiting for a locked transaction to start committing,
844 * or for a barrier lock to be released.
846 wait_queue_head_t j_wait_transaction_locked;
849 * @j_wait_done_commit: Wait queue for waiting for commit to complete.
851 wait_queue_head_t j_wait_done_commit;
854 * @j_wait_commit: Wait queue to trigger commit.
856 wait_queue_head_t j_wait_commit;
859 * @j_wait_updates: Wait queue to wait for updates to complete.
861 wait_queue_head_t j_wait_updates;
866 * Wait queue to wait for reserved buffer credits to drop.
868 wait_queue_head_t j_wait_reserved;
873 * Wait queue to wait for completion of async fast commits.
875 wait_queue_head_t j_fc_wait;
878 * @j_checkpoint_mutex:
880 * Semaphore for locking against concurrent checkpoints.
882 struct mutex j_checkpoint_mutex;
887 * List of buffer heads used by the checkpoint routine. This
888 * was moved from jbd2_log_do_checkpoint() to reduce stack
889 * usage. Access to this array is controlled by the
890 * @j_checkpoint_mutex. [j_checkpoint_mutex]
892 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
897 * Journal head shrinker, reclaim buffer's journal head which
898 * has been written back.
900 struct shrinker j_shrinker;
903 * @j_checkpoint_jh_count:
905 * Number of journal buffers on the checkpoint list. [j_list_lock]
907 struct percpu_counter j_checkpoint_jh_count;
910 * @j_shrink_transaction:
912 * Record next transaction will shrink on the checkpoint list.
915 transaction_t *j_shrink_transaction;
920 * Journal head: identifies the first unused block in the journal.
923 unsigned long j_head;
928 * Journal tail: identifies the oldest still-used block in the journal.
931 unsigned long j_tail;
936 * Journal free: how many free blocks are there in the journal?
939 unsigned long j_free;
944 * The block number of the first usable block in the journal
947 unsigned long j_first;
952 * The block number one beyond the last usable block in the journal
955 unsigned long j_last;
960 * The block number of the first fast commit block in the journal
963 unsigned long j_fc_first;
968 * Number of fast commit blocks currently allocated. Accessed only
969 * during fast commit. Currently only process can do fast commit, so
970 * this field is not protected by any lock.
972 unsigned long j_fc_off;
977 * The block number one beyond the last fast commit block in the journal
980 unsigned long j_fc_last;
983 * @j_dev: Device where we store the journal.
985 struct block_device *j_dev;
988 * @j_blocksize: Block size for the location where we store the journal.
995 * Starting block offset into the device where we store the journal.
997 unsigned long long j_blk_offset;
1000 * @j_devname: Journal device name.
1002 char j_devname[BDEVNAME_SIZE+24];
1007 * Device which holds the client fs. For internal journal this will be
1010 struct block_device *j_fs_dev;
1013 * @j_total_len: Total maximum capacity of the journal region on disk.
1015 unsigned int j_total_len;
1018 * @j_reserved_credits:
1020 * Number of buffers reserved from the running transaction.
1022 atomic_t j_reserved_credits;
1025 * @j_list_lock: Protects the buffer lists and internal buffer state.
1027 spinlock_t j_list_lock;
1032 * Optional inode where we store the journal. If present, all
1033 * journal block numbers are mapped into this inode via bmap().
1035 struct inode *j_inode;
1040 * Sequence number of the oldest transaction in the log [j_state_lock]
1042 tid_t j_tail_sequence;
1045 * @j_transaction_sequence:
1047 * Sequence number of the next transaction to grant [j_state_lock]
1049 tid_t j_transaction_sequence;
1052 * @j_commit_sequence:
1054 * Sequence number of the most recently committed transaction
1055 * [j_state_lock, no lock for quick racy checks]
1057 tid_t j_commit_sequence;
1060 * @j_commit_request:
1062 * Sequence number of the most recent transaction wanting commit
1063 * [j_state_lock, no lock for quick racy checks]
1065 tid_t j_commit_request;
1070 * Journal uuid: identifies the object (filesystem, LVM volume etc)
1071 * backed by this journal. This will eventually be replaced by an array
1072 * of uuids, allowing us to index multiple devices within a single
1073 * journal and to perform atomic updates across them.
1078 * @j_task: Pointer to the current commit thread for this journal.
1080 struct task_struct *j_task;
1083 * @j_max_transaction_buffers:
1085 * Maximum number of metadata buffers to allow in a single compound
1086 * commit transaction.
1088 int j_max_transaction_buffers;
1091 * @j_revoke_records_per_block:
1093 * Number of revoke records that fit in one descriptor block.
1095 int j_revoke_records_per_block;
1098 * @j_commit_interval:
1100 * What is the maximum transaction lifetime before we begin a commit?
1102 unsigned long j_commit_interval;
1105 * @j_commit_timer: The timer used to wakeup the commit thread.
1107 struct timer_list j_commit_timer;
1110 * @j_revoke_lock: Protect the revoke table.
1112 spinlock_t j_revoke_lock;
1117 * The revoke table - maintains the list of revoked blocks in the
1118 * current transaction.
1120 struct jbd2_revoke_table_s *j_revoke;
1123 * @j_revoke_table: Alternate revoke tables for j_revoke.
1125 struct jbd2_revoke_table_s *j_revoke_table[2];
1128 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
1130 struct buffer_head **j_wbuf;
1133 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
1134 * during a fast commit. Currently only process can do fast commit, so
1135 * this field is not protected by any lock.
1137 struct buffer_head **j_fc_wbuf;
1142 * Size of @j_wbuf array.
1149 * Size of @j_fc_wbuf array.
1154 * @j_last_sync_writer:
1156 * The pid of the last person to run a synchronous operation
1157 * through the journal.
1159 pid_t j_last_sync_writer;
1162 * @j_average_commit_time:
1164 * The average amount of time in nanoseconds it takes to commit a
1165 * transaction to disk. [j_state_lock]
1167 u64 j_average_commit_time;
1170 * @j_min_batch_time:
1172 * Minimum time that we should wait for additional filesystem operations
1173 * to get batched into a synchronous handle in microseconds.
1175 u32 j_min_batch_time;
1178 * @j_max_batch_time:
1180 * Maximum time that we should wait for additional filesystem operations
1181 * to get batched into a synchronous handle in microseconds.
1183 u32 j_max_batch_time;
1186 * @j_commit_callback:
1188 * This function is called when a transaction is closed.
1190 void (*j_commit_callback)(journal_t *,
1194 * @j_submit_inode_data_buffers:
1196 * This function is called for all inodes associated with the
1197 * committing transaction marked with JI_WRITE_DATA flag
1198 * before we start to write out the transaction to the journal.
1200 int (*j_submit_inode_data_buffers)
1201 (struct jbd2_inode *);
1204 * @j_finish_inode_data_buffers:
1206 * This function is called for all inodes associated with the
1207 * committing transaction marked with JI_WAIT_DATA flag
1208 * after we have written the transaction to the journal
1209 * but before we write out the commit block.
1211 int (*j_finish_inode_data_buffers)
1212 (struct jbd2_inode *);
1215 * Journal statistics
1219 * @j_history_lock: Protect the transactions statistics history.
1221 spinlock_t j_history_lock;
1224 * @j_proc_entry: procfs entry for the jbd statistics directory.
1226 struct proc_dir_entry *j_proc_entry;
1229 * @j_stats: Overall statistics.
1231 struct transaction_stats_s j_stats;
1234 * @j_failed_commit: Failed journal commit ID.
1236 unsigned int j_failed_commit;
1241 * An opaque pointer to fs-private information. ext3 puts its
1242 * superblock pointer here.
1249 * Reference to checksum algorithm driver via cryptoapi.
1251 struct crypto_shash *j_chksum_driver;
1256 * Precomputed journal UUID checksum for seeding other checksums.
1260 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1262 * @j_trans_commit_map:
1264 * Lockdep entity to track transaction commit dependencies. Handles
1265 * hold this "lock" for read, when we wait for commit, we acquire the
1266 * "lock" for writing. This matches the properties of jbd2 journalling
1267 * where the running transaction has to wait for all handles to be
1268 * dropped to commit that transaction and also acquiring a handle may
1269 * require transaction commit to finish.
1271 struct lockdep_map j_trans_commit_map;
1275 * @j_fc_cleanup_callback:
1277 * Clean-up after fast commit or full commit. JBD2 calls this function
1278 * after every commit operation.
1280 void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
1283 * @j_fc_replay_callback:
1285 * File-system specific function that performs replay of a fast
1286 * commit. JBD2 calls this function for each fast commit block found in
1287 * the journal. This function should return JBD2_FC_REPLAY_CONTINUE
1288 * to indicate that the block was processed correctly and more fast
1289 * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP
1290 * indicates the end of replay (no more blocks remaining). A negative
1291 * return value indicates error.
1293 int (*j_fc_replay_callback)(struct journal_s *journal,
1294 struct buffer_head *bh,
1295 enum passtype pass, int off,
1296 tid_t expected_commit_id);
1301 * Bmap function that should be used instead of the generic
1302 * VFS bmap function.
1304 int (*j_bmap)(struct journal_s *journal, sector_t *block);
1307 #define jbd2_might_wait_for_commit(j) \
1309 rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
1310 rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
1314 * We can support any known requested features iff the
1315 * superblock is not in version 1. Otherwise we fail to support any
1316 * extended sb features.
1318 static inline bool jbd2_format_support_feature(journal_t *j)
1320 return j->j_superblock->s_header.h_blocktype !=
1321 cpu_to_be32(JBD2_SUPERBLOCK_V1);
1324 /* journal feature predicate functions */
1325 #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1326 static inline bool jbd2_has_feature_##name(journal_t *j) \
1328 return (jbd2_format_support_feature(j) && \
1329 ((j)->j_superblock->s_feature_compat & \
1330 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1332 static inline void jbd2_set_feature_##name(journal_t *j) \
1334 (j)->j_superblock->s_feature_compat |= \
1335 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1337 static inline void jbd2_clear_feature_##name(journal_t *j) \
1339 (j)->j_superblock->s_feature_compat &= \
1340 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1343 #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1344 static inline bool jbd2_has_feature_##name(journal_t *j) \
1346 return (jbd2_format_support_feature(j) && \
1347 ((j)->j_superblock->s_feature_ro_compat & \
1348 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1350 static inline void jbd2_set_feature_##name(journal_t *j) \
1352 (j)->j_superblock->s_feature_ro_compat |= \
1353 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1355 static inline void jbd2_clear_feature_##name(journal_t *j) \
1357 (j)->j_superblock->s_feature_ro_compat &= \
1358 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1361 #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1362 static inline bool jbd2_has_feature_##name(journal_t *j) \
1364 return (jbd2_format_support_feature(j) && \
1365 ((j)->j_superblock->s_feature_incompat & \
1366 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1368 static inline void jbd2_set_feature_##name(journal_t *j) \
1370 (j)->j_superblock->s_feature_incompat |= \
1371 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1373 static inline void jbd2_clear_feature_##name(journal_t *j) \
1375 (j)->j_superblock->s_feature_incompat &= \
1376 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1379 JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
1381 JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
1382 JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
1383 JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
1384 JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
1385 JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
1386 JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT)
1389 * Journal flag definitions
1391 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1392 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1393 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1394 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1395 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1396 #define JBD2_BARRIER 0x020 /* Use IDE barriers */
1397 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
1398 * data write error in ordered
1400 #define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on
1401 * clean and empty filesystem
1403 #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */
1404 #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */
1405 #define JBD2_JOURNAL_FLUSH_DISCARD 0x0001
1406 #define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002
1407 #define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \
1408 JBD2_JOURNAL_FLUSH_ZEROOUT)
1411 * Journal atomic flag definitions
1413 #define JBD2_CHECKPOINT_IO_ERROR 0x001 /* Detect io error while writing
1414 * buffer back to disk */
1417 * Function declarations for the journaling transaction and buffer
1421 /* Filing buffers */
1422 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
1423 extern bool __jbd2_journal_refile_buffer(struct journal_head *);
1424 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1425 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1426 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1427 static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1429 list_add_tail(&bh->b_assoc_buffers, head);
1431 static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1433 list_del_init(&bh->b_assoc_buffers);
1436 /* Log buffer allocation */
1437 struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
1438 void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
1439 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1440 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1441 unsigned long *block);
1442 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1443 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1445 /* Commit management */
1446 extern void jbd2_journal_commit_transaction(journal_t *);
1448 /* Checkpoint list management */
1449 void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
1450 unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
1451 int __jbd2_journal_remove_checkpoint(struct journal_head *);
1452 void jbd2_journal_destroy_checkpoint(journal_t *journal);
1453 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1460 struct jbd2_buffer_trigger_type {
1462 * Fired a the moment data to write to the journal are known to be
1463 * stable - so either at the moment b_frozen_data is created or just
1464 * before a buffer is written to the journal. mapped_data is a mapped
1465 * buffer that is the frozen data for commit.
1467 void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1468 struct buffer_head *bh, void *mapped_data,
1472 * Fired during journal abort for dirty buffers that will not be
1475 void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1476 struct buffer_head *bh);
1479 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1481 struct jbd2_buffer_trigger_type *triggers);
1482 extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1483 struct jbd2_buffer_trigger_type *triggers);
1486 extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1487 struct journal_head *jh_in,
1488 struct buffer_head **bh_out,
1491 /* Transaction cache support */
1492 extern void jbd2_journal_destroy_transaction_cache(void);
1493 extern int __init jbd2_journal_init_transaction_cache(void);
1494 extern void jbd2_journal_free_transaction(transaction_t *);
1499 * We need to lock the journal during transaction state changes so that nobody
1500 * ever tries to take a handle on the running transaction while we are in the
1501 * middle of moving it to the commit phase. j_state_lock does this.
1503 * Note that the locking is completely interrupt unsafe. We never touch
1504 * journal structures from interrupts.
1507 static inline handle_t *journal_current_handle(void)
1509 return current->journal_info;
1512 /* The journaling code user interface:
1514 * Create and destroy handles
1515 * Register buffer modifications against the current transaction.
1518 extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1519 extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1520 int revoke_records, gfp_t gfp_mask,
1521 unsigned int type, unsigned int line_no);
1522 extern int jbd2_journal_restart(handle_t *, int nblocks);
1523 extern int jbd2__journal_restart(handle_t *, int nblocks,
1524 int revoke_records, gfp_t gfp_mask);
1525 extern int jbd2_journal_start_reserved(handle_t *handle,
1526 unsigned int type, unsigned int line_no);
1527 extern void jbd2_journal_free_reserved(handle_t *handle);
1528 extern int jbd2_journal_extend(handle_t *handle, int nblocks,
1529 int revoke_records);
1530 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1531 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1532 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1533 void jbd2_journal_set_triggers(struct buffer_head *,
1534 struct jbd2_buffer_trigger_type *type);
1535 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1536 extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1537 int jbd2_journal_invalidate_folio(journal_t *, struct folio *,
1538 size_t offset, size_t length);
1539 bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio);
1540 extern int jbd2_journal_stop(handle_t *);
1541 extern int jbd2_journal_flush(journal_t *journal, unsigned int flags);
1542 extern void jbd2_journal_lock_updates (journal_t *);
1543 extern void jbd2_journal_unlock_updates (journal_t *);
1545 void jbd2_journal_wait_updates(journal_t *);
1547 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1548 struct block_device *fs_dev,
1549 unsigned long long start, int len, int bsize);
1550 extern journal_t * jbd2_journal_init_inode (struct inode *);
1551 extern int jbd2_journal_update_format (journal_t *);
1552 extern int jbd2_journal_check_used_features
1553 (journal_t *, unsigned long, unsigned long, unsigned long);
1554 extern int jbd2_journal_check_available_features
1555 (journal_t *, unsigned long, unsigned long, unsigned long);
1556 extern int jbd2_journal_set_features
1557 (journal_t *, unsigned long, unsigned long, unsigned long);
1558 extern void jbd2_journal_clear_features
1559 (journal_t *, unsigned long, unsigned long, unsigned long);
1560 extern int jbd2_journal_load (journal_t *journal);
1561 extern int jbd2_journal_destroy (journal_t *);
1562 extern int jbd2_journal_recover (journal_t *journal);
1563 extern int jbd2_journal_wipe (journal_t *, int);
1564 extern int jbd2_journal_skip_recovery (journal_t *);
1565 extern void jbd2_journal_update_sb_errno(journal_t *);
1566 extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t,
1567 unsigned long, blk_opf_t);
1568 extern void jbd2_journal_abort (journal_t *, int);
1569 extern int jbd2_journal_errno (journal_t *);
1570 extern void jbd2_journal_ack_err (journal_t *);
1571 extern int jbd2_journal_clear_err (journal_t *);
1572 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1573 extern int jbd2_journal_force_commit(journal_t *);
1574 extern int jbd2_journal_force_commit_nested(journal_t *);
1575 extern int jbd2_journal_inode_ranged_write(handle_t *handle,
1576 struct jbd2_inode *inode, loff_t start_byte,
1578 extern int jbd2_journal_inode_ranged_wait(handle_t *handle,
1579 struct jbd2_inode *inode, loff_t start_byte,
1581 extern int jbd2_journal_finish_inode_data_buffers(
1582 struct jbd2_inode *jinode);
1583 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
1584 struct jbd2_inode *inode, loff_t new_size);
1585 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1586 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1589 * journal_head management
1591 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1592 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1593 void jbd2_journal_put_journal_head(struct journal_head *jh);
1598 extern struct kmem_cache *jbd2_handle_cache;
1600 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1602 return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags);
1605 static inline void jbd2_free_handle(handle_t *handle)
1607 kmem_cache_free(jbd2_handle_cache, handle);
1611 * jbd2_inode management (optional, for those file systems that want to use
1612 * dynamically allocated jbd2_inode structures)
1614 extern struct kmem_cache *jbd2_inode_cache;
1616 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1618 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
1621 static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1623 kmem_cache_free(jbd2_inode_cache, jinode);
1626 /* Primary revoke support */
1627 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1628 extern int jbd2_journal_init_revoke(journal_t *, int);
1629 extern void jbd2_journal_destroy_revoke_record_cache(void);
1630 extern void jbd2_journal_destroy_revoke_table_cache(void);
1631 extern int __init jbd2_journal_init_revoke_record_cache(void);
1632 extern int __init jbd2_journal_init_revoke_table_cache(void);
1634 extern void jbd2_journal_destroy_revoke(journal_t *);
1635 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1636 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1637 extern void jbd2_journal_write_revoke_records(transaction_t *transaction,
1638 struct list_head *log_bufs);
1640 /* Recovery revoke support */
1641 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1642 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1643 extern void jbd2_journal_clear_revoke(journal_t *);
1644 extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1645 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal);
1648 * The log thread user interface:
1650 * Request space in the current transaction, and force transaction commit
1651 * transitions on demand.
1654 int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1655 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1656 int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1657 int jbd2_transaction_committed(journal_t *journal, tid_t tid);
1658 int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1659 int jbd2_log_do_checkpoint(journal_t *journal);
1660 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1662 void __jbd2_log_wait_for_space(journal_t *journal);
1663 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1664 extern int jbd2_cleanup_journal_tail(journal_t *);
1666 /* Fast commit related APIs */
1667 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
1668 int jbd2_fc_end_commit(journal_t *journal);
1669 int jbd2_fc_end_commit_fallback(journal_t *journal);
1670 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
1671 int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1672 int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1673 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
1674 int jbd2_fc_release_bufs(journal_t *journal);
1676 static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal)
1678 return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
1684 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1685 * bit, when set, indicates that we have had a fatal error somewhere,
1686 * either inside the journaling layer or indicated to us by the client
1687 * (eg. ext3), and that we and should not commit any further
1691 static inline int is_journal_aborted(journal_t *journal)
1693 return journal->j_flags & JBD2_ABORT;
1696 static inline int is_handle_aborted(handle_t *handle)
1698 if (handle->h_aborted || !handle->h_transaction)
1700 return is_journal_aborted(handle->h_transaction->t_journal);
1703 static inline void jbd2_journal_abort_handle(handle_t *handle)
1705 handle->h_aborted = 1;
1708 #endif /* __KERNEL__ */
1710 /* Comparison functions for transaction IDs: perform comparisons using
1711 * modulo arithmetic so that they work over sequence number wraps. */
1713 static inline int tid_gt(tid_t x, tid_t y)
1715 int difference = (x - y);
1716 return (difference > 0);
1719 static inline int tid_geq(tid_t x, tid_t y)
1721 int difference = (x - y);
1722 return (difference >= 0);
1725 extern int jbd2_journal_blocks_per_page(struct inode *inode);
1726 extern size_t journal_tag_bytes(journal_t *journal);
1728 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
1730 return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j);
1733 static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1735 WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) &&
1736 journal->j_chksum_driver == NULL);
1738 return journal->j_chksum_driver != NULL;
1741 static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb)
1743 int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks);
1745 return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS;
1749 * Return number of free blocks in the log. Must be called under j_state_lock.
1751 static inline unsigned long jbd2_log_space_left(journal_t *journal)
1753 /* Allow for rounding errors */
1754 long free = journal->j_free - 32;
1756 if (journal->j_committing_transaction) {
1757 free -= atomic_read(&journal->
1758 j_committing_transaction->t_outstanding_credits);
1760 return max_t(long, free, 0);
1764 * Definitions which augment the buffer_head layer
1767 /* journaling buffer types */
1768 #define BJ_None 0 /* Not journaled */
1769 #define BJ_Metadata 1 /* Normal journaled metadata */
1770 #define BJ_Forget 2 /* Buffer superseded by this transaction */
1771 #define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1772 #define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1775 /* JBD uses a CRC32 checksum */
1776 #define JBD_MAX_CHECKSUM_SIZE 4
1778 static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
1779 const void *address, unsigned int length)
1782 struct shash_desc shash;
1783 char ctx[JBD_MAX_CHECKSUM_SIZE];
1787 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
1788 JBD_MAX_CHECKSUM_SIZE);
1790 desc.shash.tfm = journal->j_chksum_driver;
1791 *(u32 *)desc.ctx = crc;
1793 err = crypto_shash_update(&desc.shash, address, length);
1796 return *(u32 *)desc.ctx;
1799 /* Return most recent uncommitted transaction */
1800 static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
1804 read_lock(&journal->j_state_lock);
1805 tid = journal->j_commit_request;
1806 if (journal->j_running_transaction)
1807 tid = journal->j_running_transaction->t_tid;
1808 read_unlock(&journal->j_state_lock);
1812 static inline int jbd2_handle_buffer_credits(handle_t *handle)
1816 if (!handle->h_reserved)
1817 journal = handle->h_transaction->t_journal;
1819 journal = handle->h_journal;
1821 return handle->h_total_credits -
1822 DIV_ROUND_UP(handle->h_revoke_credits_requested,
1823 journal->j_revoke_records_per_block);
1828 #define buffer_trace_init(bh) do {} while (0)
1829 #define print_buffer_fields(bh) do {} while (0)
1830 #define print_buffer_trace(bh) do {} while (0)
1831 #define BUFFER_TRACE(bh, info) do {} while (0)
1832 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1833 #define JBUFFER_TRACE(jh, info) do {} while (0)
1835 #endif /* __KERNEL__ */
1837 #define EFSBADCRC EBADMSG /* Bad CRC detected */
1838 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
1840 #endif /* _LINUX_JBD2_H */