2 * linux/include/linux/jbd2.h
4 * Written by Stephen C. Tweedie <sct@redhat.com>
6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
12 * Definitions for transaction data structures for the buffer cache
13 * filesystem journaling support.
19 /* Allow this file to be included directly into e2fsprogs */
21 #include "jfs_compat.h"
25 #include <linux/types.h>
26 #include <linux/buffer_head.h>
27 #include <linux/journal-head.h>
28 #include <linux/stddef.h>
29 #include <linux/mutex.h>
30 #include <linux/timer.h>
31 #include <linux/slab.h>
32 #include <linux/bit_spinlock.h>
33 #include <crypto/hash.h>
36 #define journal_oom_retry 1
39 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
40 * certain classes of error which can occur due to failed IOs. Under
41 * normal use we want ext4 to continue after such errors, because
42 * hardware _can_ fail, but for debugging purposes when running tests on
43 * known-good hardware we may want to trap these errors.
45 #undef JBD2_PARANOID_IOFAIL
48 * The default maximum commit age, in seconds.
50 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
52 #ifdef CONFIG_JBD2_DEBUG
54 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
55 * consistency checks. By default we don't do this unless
56 * CONFIG_JBD2_DEBUG is on.
58 #define JBD2_EXPENSIVE_CHECKING
59 extern ushort jbd2_journal_enable_debug;
60 void __jbd2_debug(int level, const char *file, const char *func,
61 unsigned int line, const char *fmt, ...);
63 #define jbd_debug(n, fmt, a...) \
64 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
66 #define jbd_debug(n, fmt, a...) /**/
69 extern void *jbd2_alloc(size_t size, gfp_t flags);
70 extern void jbd2_free(void *ptr, size_t size);
72 #define JBD2_MIN_JOURNAL_BLOCKS 1024
77 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
79 * All filesystem modifications made by the process go
80 * through this handle. Recursive operations (such as quota operations)
81 * are gathered into a single update.
83 * The buffer credits field is used to account for journaled buffers
84 * being modified by the running process. To ensure that there is
85 * enough log space for all outstanding operations, we need to limit the
86 * number of outstanding buffers possible at any time. When the
87 * operation completes, any buffer credits not used are credited back to
88 * the transaction, so that at all times we know how many buffers the
89 * outstanding updates on a transaction might possibly touch.
91 * This is an opaque datatype.
93 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */
97 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
99 * journal_t is linked to from the fs superblock structure.
101 * We use the journal_t to keep track of all outstanding transaction
102 * activity on the filesystem, and to manage the state of the log
105 * This is an opaque datatype.
107 typedef struct journal_s journal_t; /* Journal control structure */
111 * Internal structures used by the logging mechanism:
114 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
121 * Descriptor block types:
124 #define JBD2_DESCRIPTOR_BLOCK 1
125 #define JBD2_COMMIT_BLOCK 2
126 #define JBD2_SUPERBLOCK_V1 3
127 #define JBD2_SUPERBLOCK_V2 4
128 #define JBD2_REVOKE_BLOCK 5
131 * Standard header for all descriptor blocks:
133 typedef struct journal_header_s
143 #define JBD2_CRC32_CHKSUM 1
144 #define JBD2_MD5_CHKSUM 2
145 #define JBD2_SHA1_CHKSUM 3
146 #define JBD2_CRC32C_CHKSUM 4
148 #define JBD2_CRC32_CHKSUM_SIZE 4
150 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
152 * Commit block header for storing transactional checksums:
154 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
155 * fields are used to store a checksum of the descriptor and data blocks.
157 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
158 * field is used to store crc32c(uuid+commit_block). Each journal metadata
159 * block gets its own checksum, and data block checksums are stored in
160 * journal_block_tag (in the descriptor). The other h_chksum* fields are
163 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
164 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
167 * Checksum v1, v2, and v3 are mutually exclusive features.
169 struct commit_header {
173 unsigned char h_chksum_type;
174 unsigned char h_chksum_size;
175 unsigned char h_padding[2];
176 __be32 h_chksum[JBD2_CHECKSUM_BYTES];
178 __be32 h_commit_nsec;
182 * The block tag: used to describe a single buffer in the journal.
183 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
184 * raw struct shouldn't be used for pointer math or sizeof() - use
185 * journal_tag_bytes(journal) instead to compute this.
187 typedef struct journal_block_tag3_s
189 __be32 t_blocknr; /* The on-disk block number */
190 __be32 t_flags; /* See below */
191 __be32 t_blocknr_high; /* most-significant high 32bits. */
192 __be32 t_checksum; /* crc32c(uuid+seq+block) */
193 } journal_block_tag3_t;
195 typedef struct journal_block_tag_s
197 __be32 t_blocknr; /* The on-disk block number */
198 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */
199 __be16 t_flags; /* See below */
200 __be32 t_blocknr_high; /* most-significant high 32bits. */
201 } journal_block_tag_t;
203 /* Tail of descriptor block, for checksumming */
204 struct jbd2_journal_block_tail {
205 __be32 t_checksum; /* crc32c(uuid+descr_block) */
209 * The revoke descriptor: used on disk to describe a series of blocks to
210 * be revoked from the log
212 typedef struct jbd2_journal_revoke_header_s
214 journal_header_t r_header;
215 __be32 r_count; /* Count of bytes used in the block */
216 } jbd2_journal_revoke_header_t;
218 /* Tail of revoke block, for checksumming */
219 struct jbd2_journal_revoke_tail {
220 __be32 r_checksum; /* crc32c(uuid+revoke_block) */
223 /* Definitions for the journal tag flags word: */
224 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */
225 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */
226 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */
227 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
231 * The journal superblock. All fields are in big-endian byte order.
233 typedef struct journal_superblock_s
236 journal_header_t s_header;
239 /* Static information describing the journal */
240 __be32 s_blocksize; /* journal device blocksize */
241 __be32 s_maxlen; /* total blocks in journal file */
242 __be32 s_first; /* first block of log information */
245 /* Dynamic information describing the current state of the log */
246 __be32 s_sequence; /* first commit ID expected in log */
247 __be32 s_start; /* blocknr of start of log */
250 /* Error value, as set by jbd2_journal_abort(). */
254 /* Remaining fields are only valid in a version-2 superblock */
255 __be32 s_feature_compat; /* compatible feature set */
256 __be32 s_feature_incompat; /* incompatible feature set */
257 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
259 __u8 s_uuid[16]; /* 128-bit uuid for journal */
262 __be32 s_nr_users; /* Nr of filesystems sharing log */
264 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
267 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
268 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
271 __u8 s_checksum_type; /* checksum type */
274 __be32 s_checksum; /* crc32c(superblock) */
277 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
279 } journal_superblock_t;
281 /* Use the jbd2_{has,set,clear}_feature_* helpers; these will be removed */
282 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \
283 ((j)->j_format_version >= 2 && \
284 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
285 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \
286 ((j)->j_format_version >= 2 && \
287 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
288 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \
289 ((j)->j_format_version >= 2 && \
290 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
292 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001
294 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001
295 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002
296 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
297 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008
298 #define JBD2_FEATURE_INCOMPAT_CSUM_V3 0x00000010
300 /* See "journal feature predicate functions" below */
302 /* Features known to this kernel version: */
303 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM
304 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0
305 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \
306 JBD2_FEATURE_INCOMPAT_64BIT | \
307 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
308 JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
309 JBD2_FEATURE_INCOMPAT_CSUM_V3)
313 #include <linux/fs.h>
314 #include <linux/sched.h>
316 enum jbd_state_bits {
317 BH_JBD /* Has an attached ext3 journal_head */
319 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
320 BH_Freed, /* Has been freed (truncated) */
321 BH_Revoked, /* Has been revoked from the log */
322 BH_RevokeValid, /* Revoked flag is valid */
323 BH_JBDDirty, /* Is dirty but journaled */
324 BH_State, /* Pins most journal_head state */
325 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
326 BH_Shadow, /* IO on shadow buffer is running */
327 BH_Verified, /* Metadata block has been verified ok */
328 BH_JBDPrivateStart, /* First bit available for private use by FS */
332 BUFFER_FNS(JWrite, jwrite)
333 BUFFER_FNS(JBDDirty, jbddirty)
334 TAS_BUFFER_FNS(JBDDirty, jbddirty)
335 BUFFER_FNS(Revoked, revoked)
336 TAS_BUFFER_FNS(Revoked, revoked)
337 BUFFER_FNS(RevokeValid, revokevalid)
338 TAS_BUFFER_FNS(RevokeValid, revokevalid)
339 BUFFER_FNS(Freed, freed)
340 BUFFER_FNS(Shadow, shadow)
341 BUFFER_FNS(Verified, verified)
343 static inline struct buffer_head *jh2bh(struct journal_head *jh)
348 static inline struct journal_head *bh2jh(struct buffer_head *bh)
350 return bh->b_private;
353 static inline void jbd_lock_bh_state(struct buffer_head *bh)
355 #ifndef CONFIG_PREEMPT_RT_BASE
356 bit_spin_lock(BH_State, &bh->b_state);
358 spin_lock(&bh->b_state_lock);
362 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
364 #ifndef CONFIG_PREEMPT_RT_BASE
365 return bit_spin_trylock(BH_State, &bh->b_state);
367 return spin_trylock(&bh->b_state_lock);
371 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
373 #ifndef CONFIG_PREEMPT_RT_BASE
374 return bit_spin_is_locked(BH_State, &bh->b_state);
376 return spin_is_locked(&bh->b_state_lock);
380 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
382 #ifndef CONFIG_PREEMPT_RT_BASE
383 bit_spin_unlock(BH_State, &bh->b_state);
385 spin_unlock(&bh->b_state_lock);
389 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
391 #ifndef CONFIG_PREEMPT_RT_BASE
392 bit_spin_lock(BH_JournalHead, &bh->b_state);
394 spin_lock(&bh->b_journal_head_lock);
398 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
400 #ifndef CONFIG_PREEMPT_RT_BASE
401 bit_spin_unlock(BH_JournalHead, &bh->b_state);
403 spin_unlock(&bh->b_journal_head_lock);
407 #define J_ASSERT(assert) BUG_ON(!(assert))
409 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
410 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
412 #if defined(JBD2_PARANOID_IOFAIL)
413 #define J_EXPECT(expr, why...) J_ASSERT(expr)
414 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
415 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
417 #define __journal_expect(expr, why...) \
422 "JBD2 unexpected failure: %s: %s;\n", \
424 printk(KERN_ERR why "\n"); \
428 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
429 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
430 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
433 /* Flags in jbd_inode->i_flags */
434 #define __JI_COMMIT_RUNNING 0
435 /* Commit of the inode data in progress. We use this flag to protect us from
436 * concurrent deletion of inode. We cannot use reference to inode for this
437 * since we cannot afford doing last iput() on behalf of kjournald
439 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
442 * struct jbd_inode is the structure linking inodes in ordered mode
443 * present in a transaction so that we can sync them during commit.
446 /* Which transaction does this inode belong to? Either the running
447 * transaction or the committing one. [j_list_lock] */
448 transaction_t *i_transaction;
450 /* Pointer to the running transaction modifying inode's data in case
451 * there is already a committing transaction touching it. [j_list_lock] */
452 transaction_t *i_next_transaction;
454 /* List of inodes in the i_transaction [j_list_lock] */
455 struct list_head i_list;
457 /* VFS inode this inode belongs to [constant during the lifetime
458 * of the structure] */
459 struct inode *i_vfs_inode;
461 /* Flags of inode [j_list_lock] */
462 unsigned long i_flags;
465 struct jbd2_revoke_table_s;
468 * struct handle_s - The handle_s type is the concrete type associated with
470 * @h_transaction: Which compound transaction is this update a part of?
471 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
472 * @h_ref: Reference count on this handle
473 * @h_err: Field for caller's use to track errors through large fs operations
474 * @h_sync: flag for sync-on-close
475 * @h_jdata: flag to force data journaling
476 * @h_aborted: flag indicating fatal error on handle
479 /* Docbook can't yet cope with the bit fields, but will leave the documentation
480 * in so it can be fixed later.
483 struct jbd2_journal_handle
486 /* Which compound transaction is this update a part of? */
487 transaction_t *h_transaction;
488 /* Which journal handle belongs to - used iff h_reserved set */
489 journal_t *h_journal;
492 /* Handle reserved for finishing the logical operation */
493 handle_t *h_rsv_handle;
495 /* Number of remaining buffers we are allowed to dirty: */
496 int h_buffer_credits;
498 /* Reference count on this handle */
501 /* Field for caller's use to track errors through large fs */
505 /* Flags [no locking] */
506 unsigned int h_sync: 1; /* sync-on-close */
507 unsigned int h_jdata: 1; /* force data journaling */
508 unsigned int h_reserved: 1; /* handle with reserved credits */
509 unsigned int h_aborted: 1; /* fatal error on handle */
510 unsigned int h_type: 8; /* for handle statistics */
511 unsigned int h_line_no: 16; /* for handle statistics */
513 unsigned long h_start_jiffies;
514 unsigned int h_requested_credits;
516 #ifdef CONFIG_DEBUG_LOCK_ALLOC
517 struct lockdep_map h_lockdep_map;
523 * Some stats for checkpoint phase
525 struct transaction_chp_stats_s {
526 unsigned long cs_chp_time;
527 __u32 cs_forced_to_close;
532 /* The transaction_t type is the guts of the journaling mechanism. It
533 * tracks a compound transaction through its various states:
535 * RUNNING: accepting new updates
536 * LOCKED: Updates still running but we don't accept new ones
537 * RUNDOWN: Updates are tidying up but have finished requesting
538 * new buffers to modify (state not used for now)
539 * FLUSH: All updates complete, but we are still writing to disk
540 * COMMIT: All data on disk, writing commit record
541 * FINISHED: We still have to keep the transaction for checkpointing.
543 * The transaction keeps track of all of the buffers modified by a
544 * running transaction, and all of the buffers committed but not yet
545 * flushed to home for finished transactions.
552 * ->jbd_lock_bh_journal_head() (This is "innermost")
555 * ->jbd_lock_bh_state()
557 * jbd_lock_bh_state()
564 * ->j_list_lock (journal_unmap_buffer)
570 /* Pointer to the journal for this transaction. [no locking] */
571 journal_t *t_journal;
573 /* Sequence number for this transaction [no locking] */
577 * Transaction's current state
578 * [no locking - only kjournald2 alters this]
579 * [j_list_lock] guards transition of a transaction into T_FINISHED
580 * state and subsequent call of __jbd2_journal_drop_transaction()
581 * FIXME: needs barriers
582 * KLUDGE: [use j_state_lock]
596 * Where in the log does this transaction's commit start? [no locking]
598 unsigned long t_log_start;
600 /* Number of buffers on the t_buffers list [j_list_lock] */
604 * Doubly-linked circular list of all buffers reserved but not yet
605 * modified by this transaction [j_list_lock]
607 struct journal_head *t_reserved_list;
610 * Doubly-linked circular list of all metadata buffers owned by this
611 * transaction [j_list_lock]
613 struct journal_head *t_buffers;
616 * Doubly-linked circular list of all forget buffers (superseded
617 * buffers which we can un-checkpoint once this transaction commits)
620 struct journal_head *t_forget;
623 * Doubly-linked circular list of all buffers still to be flushed before
624 * this transaction can be checkpointed. [j_list_lock]
626 struct journal_head *t_checkpoint_list;
629 * Doubly-linked circular list of all buffers submitted for IO while
630 * checkpointing. [j_list_lock]
632 struct journal_head *t_checkpoint_io_list;
635 * Doubly-linked circular list of metadata buffers being shadowed by log
636 * IO. The IO buffers on the iobuf list and the shadow buffers on this
637 * list match each other one for one at all times. [j_list_lock]
639 struct journal_head *t_shadow_list;
642 * List of inodes whose data we've modified in data=ordered mode.
645 struct list_head t_inode_list;
648 * Protects info related to handles
650 spinlock_t t_handle_lock;
653 * Longest time some handle had to wait for running transaction
655 unsigned long t_max_wait;
658 * When transaction started
660 unsigned long t_start;
663 * When commit was requested
665 unsigned long t_requested;
668 * Checkpointing stats [j_checkpoint_sem]
670 struct transaction_chp_stats_s t_chp_stats;
673 * Number of outstanding updates running on this transaction
679 * Number of buffers reserved for use by all handles in this transaction
680 * handle but not yet modified. [t_handle_lock]
682 atomic_t t_outstanding_credits;
685 * Forward and backward links for the circular list of all transactions
686 * awaiting checkpoint. [j_list_lock]
688 transaction_t *t_cpnext, *t_cpprev;
691 * When will the transaction expire (become due for commit), in jiffies?
694 unsigned long t_expires;
697 * When this transaction started, in nanoseconds [no locking]
699 ktime_t t_start_time;
702 * How many handles used this transaction? [t_handle_lock]
704 atomic_t t_handle_count;
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
753 * struct journal_s - The journal_s type is the concrete type associated with
755 * @j_flags: General journaling state flags
756 * @j_errno: Is there an outstanding uncleared error on the journal (from a
758 * @j_sb_buffer: First part of superblock buffer
759 * @j_superblock: Second part of superblock buffer
760 * @j_format_version: Version of the superblock format
761 * @j_state_lock: Protect the various scalars in the journal
762 * @j_barrier_count: Number of processes waiting to create a barrier lock
763 * @j_barrier: The barrier lock itself
764 * @j_running_transaction: The current running transaction..
765 * @j_committing_transaction: the transaction we are pushing to disk
766 * @j_checkpoint_transactions: a linked circular list of all transactions
767 * waiting for checkpointing
768 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
769 * to start committing, or for a barrier lock to be released
770 * @j_wait_done_commit: Wait queue for waiting for commit to complete
771 * @j_wait_commit: Wait queue to trigger commit
772 * @j_wait_updates: Wait queue to wait for updates to complete
773 * @j_wait_reserved: Wait queue to wait for reserved buffer credits to drop
774 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
775 * @j_head: Journal head - identifies the first unused block in the journal
776 * @j_tail: Journal tail - identifies the oldest still-used block in the
778 * @j_free: Journal free - how many free blocks are there in the journal?
779 * @j_first: The block number of the first usable block
780 * @j_last: The block number one beyond the last usable block
781 * @j_dev: Device where we store the journal
782 * @j_blocksize: blocksize for the location where we store the journal.
783 * @j_blk_offset: starting block offset for into the device where we store the
785 * @j_fs_dev: Device which holds the client fs. For internal journal this will
787 * @j_reserved_credits: Number of buffers reserved from the running transaction
788 * @j_maxlen: Total maximum capacity of the journal region on disk.
789 * @j_list_lock: Protects the buffer lists and internal buffer state.
790 * @j_inode: Optional inode where we store the journal. If present, all journal
791 * block numbers are mapped into this inode via bmap().
792 * @j_tail_sequence: Sequence number of the oldest transaction in the log
793 * @j_transaction_sequence: Sequence number of the next transaction to grant
794 * @j_commit_sequence: Sequence number of the most recently committed
796 * @j_commit_request: Sequence number of the most recent transaction wanting
798 * @j_uuid: Uuid of client object.
799 * @j_task: Pointer to the current commit thread for this journal
800 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
801 * single compound commit transaction
802 * @j_commit_interval: What is the maximum transaction lifetime before we begin
804 * @j_commit_timer: The timer used to wakeup the commit thread
805 * @j_revoke_lock: Protect the revoke table
806 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
807 * current transaction.
808 * @j_revoke_table: alternate revoke tables for j_revoke
809 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction
810 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
811 * number that will fit in j_blocksize
812 * @j_last_sync_writer: most recent pid which did a synchronous write
813 * @j_history: Buffer storing the transactions statistics history
814 * @j_history_max: Maximum number of transactions in the statistics history
815 * @j_history_cur: Current number of transactions in the statistics history
816 * @j_history_lock: Protect the transactions statistics history
817 * @j_proc_entry: procfs entry for the jbd statistics directory
818 * @j_stats: Overall statistics
819 * @j_private: An opaque pointer to fs-private information.
824 /* General journaling state flags [j_state_lock] */
825 unsigned long j_flags;
828 * Is there an outstanding uncleared error on the journal (from a prior
829 * abort)? [j_state_lock]
833 /* The superblock buffer */
834 struct buffer_head *j_sb_buffer;
835 journal_superblock_t *j_superblock;
837 /* Version of the superblock format */
838 int j_format_version;
841 * Protect the various scalars in the journal
843 rwlock_t j_state_lock;
846 * Number of processes waiting to create a barrier lock [j_state_lock]
850 /* The barrier lock itself */
851 struct mutex j_barrier;
854 * Transactions: The current running transaction...
855 * [j_state_lock] [caller holding open handle]
857 transaction_t *j_running_transaction;
860 * the transaction we are pushing to disk
861 * [j_state_lock] [caller holding open handle]
863 transaction_t *j_committing_transaction;
866 * ... and a linked circular list of all transactions waiting for
867 * checkpointing. [j_list_lock]
869 transaction_t *j_checkpoint_transactions;
872 * Wait queue for waiting for a locked transaction to start committing,
873 * or for a barrier lock to be released
875 wait_queue_head_t j_wait_transaction_locked;
877 /* Wait queue for waiting for commit to complete */
878 wait_queue_head_t j_wait_done_commit;
880 /* Wait queue to trigger commit */
881 wait_queue_head_t j_wait_commit;
883 /* Wait queue to wait for updates to complete */
884 wait_queue_head_t j_wait_updates;
886 /* Wait queue to wait for reserved buffer credits to drop */
887 wait_queue_head_t j_wait_reserved;
889 /* Semaphore for locking against concurrent checkpoints */
890 struct mutex j_checkpoint_mutex;
893 * List of buffer heads used by the checkpoint routine. This
894 * was moved from jbd2_log_do_checkpoint() to reduce stack
895 * usage. Access to this array is controlled by the
896 * j_checkpoint_mutex. [j_checkpoint_mutex]
898 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
901 * Journal head: identifies the first unused block in the journal.
904 unsigned long j_head;
907 * Journal tail: identifies the oldest still-used block in the journal.
910 unsigned long j_tail;
913 * Journal free: how many free blocks are there in the journal?
916 unsigned long j_free;
919 * Journal start and end: the block numbers of the first usable block
920 * and one beyond the last usable block in the journal. [j_state_lock]
922 unsigned long j_first;
923 unsigned long j_last;
926 * Device, blocksize and starting block offset for the location where we
929 struct block_device *j_dev;
931 unsigned long long j_blk_offset;
932 char j_devname[BDEVNAME_SIZE+24];
935 * Device which holds the client fs. For internal journal this will be
938 struct block_device *j_fs_dev;
940 /* Total maximum capacity of the journal region on disk. */
941 unsigned int j_maxlen;
943 /* Number of buffers reserved from the running transaction */
944 atomic_t j_reserved_credits;
947 * Protects the buffer lists and internal buffer state.
949 spinlock_t j_list_lock;
951 /* Optional inode where we store the journal. If present, all */
952 /* journal block numbers are mapped into this inode via */
954 struct inode *j_inode;
957 * Sequence number of the oldest transaction in the log [j_state_lock]
959 tid_t j_tail_sequence;
962 * Sequence number of the next transaction to grant [j_state_lock]
964 tid_t j_transaction_sequence;
967 * Sequence number of the most recently committed transaction
970 tid_t j_commit_sequence;
973 * Sequence number of the most recent transaction wanting commit
976 tid_t j_commit_request;
979 * Journal uuid: identifies the object (filesystem, LVM volume etc)
980 * backed by this journal. This will eventually be replaced by an array
981 * of uuids, allowing us to index multiple devices within a single
982 * journal and to perform atomic updates across them.
986 /* Pointer to the current commit thread for this journal */
987 struct task_struct *j_task;
990 * Maximum number of metadata buffers to allow in a single compound
993 int j_max_transaction_buffers;
996 * What is the maximum transaction lifetime before we begin a commit?
998 unsigned long j_commit_interval;
1000 /* The timer used to wakeup the commit thread: */
1001 struct timer_list j_commit_timer;
1004 * The revoke table: maintains the list of revoked blocks in the
1005 * current transaction. [j_revoke_lock]
1007 spinlock_t j_revoke_lock;
1008 struct jbd2_revoke_table_s *j_revoke;
1009 struct jbd2_revoke_table_s *j_revoke_table[2];
1012 * array of bhs for jbd2_journal_commit_transaction
1014 struct buffer_head **j_wbuf;
1018 * this is the pid of hte last person to run a synchronous operation
1019 * through the journal
1021 pid_t j_last_sync_writer;
1024 * the average amount of time in nanoseconds it takes to commit a
1025 * transaction to disk. [j_state_lock]
1027 u64 j_average_commit_time;
1030 * minimum and maximum times that we should wait for
1031 * additional filesystem operations to get batched into a
1032 * synchronous handle in microseconds
1034 u32 j_min_batch_time;
1035 u32 j_max_batch_time;
1037 /* This function is called when a transaction is closed */
1038 void (*j_commit_callback)(journal_t *,
1042 * Journal statistics
1044 spinlock_t j_history_lock;
1045 struct proc_dir_entry *j_proc_entry;
1046 struct transaction_stats_s j_stats;
1048 /* Failed journal commit ID */
1049 unsigned int j_failed_commit;
1052 * An opaque pointer to fs-private information. ext3 puts its
1053 * superblock pointer here
1057 /* Reference to checksum algorithm driver via cryptoapi */
1058 struct crypto_shash *j_chksum_driver;
1060 /* Precomputed journal UUID checksum for seeding other checksums */
1064 /* journal feature predicate functions */
1065 #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1066 static inline bool jbd2_has_feature_##name(journal_t *j) \
1068 return ((j)->j_format_version >= 2 && \
1069 ((j)->j_superblock->s_feature_compat & \
1070 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1072 static inline void jbd2_set_feature_##name(journal_t *j) \
1074 (j)->j_superblock->s_feature_compat |= \
1075 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1077 static inline void jbd2_clear_feature_##name(journal_t *j) \
1079 (j)->j_superblock->s_feature_compat &= \
1080 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1083 #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1084 static inline bool jbd2_has_feature_##name(journal_t *j) \
1086 return ((j)->j_format_version >= 2 && \
1087 ((j)->j_superblock->s_feature_ro_compat & \
1088 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1090 static inline void jbd2_set_feature_##name(journal_t *j) \
1092 (j)->j_superblock->s_feature_ro_compat |= \
1093 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1095 static inline void jbd2_clear_feature_##name(journal_t *j) \
1097 (j)->j_superblock->s_feature_ro_compat &= \
1098 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1101 #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1102 static inline bool jbd2_has_feature_##name(journal_t *j) \
1104 return ((j)->j_format_version >= 2 && \
1105 ((j)->j_superblock->s_feature_incompat & \
1106 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1108 static inline void jbd2_set_feature_##name(journal_t *j) \
1110 (j)->j_superblock->s_feature_incompat |= \
1111 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1113 static inline void jbd2_clear_feature_##name(journal_t *j) \
1115 (j)->j_superblock->s_feature_incompat &= \
1116 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1119 JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM)
1121 JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE)
1122 JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT)
1123 JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT)
1124 JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2)
1125 JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3)
1128 * Journal flag definitions
1130 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1131 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1132 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1133 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1134 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1135 #define JBD2_BARRIER 0x020 /* Use IDE barriers */
1136 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
1137 * data write error in ordered
1139 #define JBD2_REC_ERR 0x080 /* The errno in the sb has been recorded */
1142 * Function declarations for the journaling transaction and buffer
1146 /* Filing buffers */
1147 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
1148 extern void __jbd2_journal_refile_buffer(struct journal_head *);
1149 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1150 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1151 extern void __journal_free_buffer(struct journal_head *bh);
1152 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1153 extern void __journal_clean_data_list(transaction_t *transaction);
1154 static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1156 list_add_tail(&bh->b_assoc_buffers, head);
1158 static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1160 list_del_init(&bh->b_assoc_buffers);
1163 /* Log buffer allocation */
1164 struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal);
1165 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1166 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1167 unsigned long *block);
1168 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1169 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1171 /* Commit management */
1172 extern void jbd2_journal_commit_transaction(journal_t *);
1174 /* Checkpoint list management */
1175 void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
1176 int __jbd2_journal_remove_checkpoint(struct journal_head *);
1177 void jbd2_journal_destroy_checkpoint(journal_t *journal);
1178 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1185 struct jbd2_buffer_trigger_type {
1187 * Fired a the moment data to write to the journal are known to be
1188 * stable - so either at the moment b_frozen_data is created or just
1189 * before a buffer is written to the journal. mapped_data is a mapped
1190 * buffer that is the frozen data for commit.
1192 void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1193 struct buffer_head *bh, void *mapped_data,
1197 * Fired during journal abort for dirty buffers that will not be
1200 void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1201 struct buffer_head *bh);
1204 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1206 struct jbd2_buffer_trigger_type *triggers);
1207 extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1208 struct jbd2_buffer_trigger_type *triggers);
1211 extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1212 struct journal_head *jh_in,
1213 struct buffer_head **bh_out,
1216 /* Transaction locking */
1217 extern void __wait_on_journal (journal_t *);
1219 /* Transaction cache support */
1220 extern void jbd2_journal_destroy_transaction_cache(void);
1221 extern int jbd2_journal_init_transaction_cache(void);
1222 extern void jbd2_journal_free_transaction(transaction_t *);
1227 * We need to lock the journal during transaction state changes so that nobody
1228 * ever tries to take a handle on the running transaction while we are in the
1229 * middle of moving it to the commit phase. j_state_lock does this.
1231 * Note that the locking is completely interrupt unsafe. We never touch
1232 * journal structures from interrupts.
1235 static inline handle_t *journal_current_handle(void)
1237 return current->journal_info;
1240 /* The journaling code user interface:
1242 * Create and destroy handles
1243 * Register buffer modifications against the current transaction.
1246 extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1247 extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1248 gfp_t gfp_mask, unsigned int type,
1249 unsigned int line_no);
1250 extern int jbd2_journal_restart(handle_t *, int nblocks);
1251 extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask);
1252 extern int jbd2_journal_start_reserved(handle_t *handle,
1253 unsigned int type, unsigned int line_no);
1254 extern void jbd2_journal_free_reserved(handle_t *handle);
1255 extern int jbd2_journal_extend (handle_t *, int nblocks);
1256 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1257 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1258 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1259 void jbd2_journal_set_triggers(struct buffer_head *,
1260 struct jbd2_buffer_trigger_type *type);
1261 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1262 extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1263 extern void journal_sync_buffer (struct buffer_head *);
1264 extern int jbd2_journal_invalidatepage(journal_t *,
1265 struct page *, unsigned int, unsigned int);
1266 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
1267 extern int jbd2_journal_stop(handle_t *);
1268 extern int jbd2_journal_flush (journal_t *);
1269 extern void jbd2_journal_lock_updates (journal_t *);
1270 extern void jbd2_journal_unlock_updates (journal_t *);
1272 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1273 struct block_device *fs_dev,
1274 unsigned long long start, int len, int bsize);
1275 extern journal_t * jbd2_journal_init_inode (struct inode *);
1276 extern int jbd2_journal_update_format (journal_t *);
1277 extern int jbd2_journal_check_used_features
1278 (journal_t *, unsigned long, unsigned long, unsigned long);
1279 extern int jbd2_journal_check_available_features
1280 (journal_t *, unsigned long, unsigned long, unsigned long);
1281 extern int jbd2_journal_set_features
1282 (journal_t *, unsigned long, unsigned long, unsigned long);
1283 extern void jbd2_journal_clear_features
1284 (journal_t *, unsigned long, unsigned long, unsigned long);
1285 extern int jbd2_journal_load (journal_t *journal);
1286 extern int jbd2_journal_destroy (journal_t *);
1287 extern int jbd2_journal_recover (journal_t *journal);
1288 extern int jbd2_journal_wipe (journal_t *, int);
1289 extern int jbd2_journal_skip_recovery (journal_t *);
1290 extern void jbd2_journal_update_sb_errno(journal_t *);
1291 extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t,
1292 unsigned long, int);
1293 extern void __jbd2_journal_abort_hard (journal_t *);
1294 extern void jbd2_journal_abort (journal_t *, int);
1295 extern int jbd2_journal_errno (journal_t *);
1296 extern void jbd2_journal_ack_err (journal_t *);
1297 extern int jbd2_journal_clear_err (journal_t *);
1298 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1299 extern int jbd2_journal_force_commit(journal_t *);
1300 extern int jbd2_journal_force_commit_nested(journal_t *);
1301 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode);
1302 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal,
1303 struct jbd2_inode *inode, loff_t new_size);
1304 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1305 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1308 * journal_head management
1310 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1311 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1312 void jbd2_journal_put_journal_head(struct journal_head *jh);
1317 extern struct kmem_cache *jbd2_handle_cache;
1319 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1321 return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags);
1324 static inline void jbd2_free_handle(handle_t *handle)
1326 kmem_cache_free(jbd2_handle_cache, handle);
1330 * jbd2_inode management (optional, for those file systems that want to use
1331 * dynamically allocated jbd2_inode structures)
1333 extern struct kmem_cache *jbd2_inode_cache;
1335 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1337 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
1340 static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1342 kmem_cache_free(jbd2_inode_cache, jinode);
1345 /* Primary revoke support */
1346 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1347 extern int jbd2_journal_init_revoke(journal_t *, int);
1348 extern void jbd2_journal_destroy_revoke_caches(void);
1349 extern int jbd2_journal_init_revoke_caches(void);
1351 extern void jbd2_journal_destroy_revoke(journal_t *);
1352 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1353 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1354 extern void jbd2_journal_write_revoke_records(journal_t *journal,
1355 transaction_t *transaction,
1356 struct list_head *log_bufs,
1359 /* Recovery revoke support */
1360 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1361 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1362 extern void jbd2_journal_clear_revoke(journal_t *);
1363 extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1364 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal);
1367 * The log thread user interface:
1369 * Request space in the current transaction, and force transaction commit
1370 * transitions on demand.
1373 int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1374 int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
1375 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1376 int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1377 int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1378 int jbd2_log_do_checkpoint(journal_t *journal);
1379 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1381 void __jbd2_log_wait_for_space(journal_t *journal);
1382 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1383 extern int jbd2_cleanup_journal_tail(journal_t *);
1388 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1389 * bit, when set, indicates that we have had a fatal error somewhere,
1390 * either inside the journaling layer or indicated to us by the client
1391 * (eg. ext3), and that we and should not commit any further
1395 static inline int is_journal_aborted(journal_t *journal)
1397 return journal->j_flags & JBD2_ABORT;
1400 static inline int is_handle_aborted(handle_t *handle)
1402 if (handle->h_aborted || !handle->h_transaction)
1404 return is_journal_aborted(handle->h_transaction->t_journal);
1407 static inline void jbd2_journal_abort_handle(handle_t *handle)
1409 handle->h_aborted = 1;
1412 #endif /* __KERNEL__ */
1414 /* Comparison functions for transaction IDs: perform comparisons using
1415 * modulo arithmetic so that they work over sequence number wraps. */
1417 static inline int tid_gt(tid_t x, tid_t y)
1419 int difference = (x - y);
1420 return (difference > 0);
1423 static inline int tid_geq(tid_t x, tid_t y)
1425 int difference = (x - y);
1426 return (difference >= 0);
1429 extern int jbd2_journal_blocks_per_page(struct inode *inode);
1430 extern size_t journal_tag_bytes(journal_t *journal);
1432 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
1434 return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j);
1437 static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1439 WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) &&
1440 journal->j_chksum_driver == NULL);
1442 return journal->j_chksum_driver != NULL;
1446 * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for
1447 * transaction control blocks.
1449 #define JBD2_CONTROL_BLOCKS_SHIFT 5
1452 * Return the minimum number of blocks which must be free in the journal
1453 * before a new transaction may be started. Must be called under j_state_lock.
1455 static inline int jbd2_space_needed(journal_t *journal)
1457 int nblocks = journal->j_max_transaction_buffers;
1458 return nblocks + (nblocks >> JBD2_CONTROL_BLOCKS_SHIFT);
1462 * Return number of free blocks in the log. Must be called under j_state_lock.
1464 static inline unsigned long jbd2_log_space_left(journal_t *journal)
1466 /* Allow for rounding errors */
1467 unsigned long free = journal->j_free - 32;
1469 if (journal->j_committing_transaction) {
1470 unsigned long committing = atomic_read(&journal->
1471 j_committing_transaction->t_outstanding_credits);
1473 /* Transaction + control blocks */
1474 free -= committing + (committing >> JBD2_CONTROL_BLOCKS_SHIFT);
1480 * Definitions which augment the buffer_head layer
1483 /* journaling buffer types */
1484 #define BJ_None 0 /* Not journaled */
1485 #define BJ_Metadata 1 /* Normal journaled metadata */
1486 #define BJ_Forget 2 /* Buffer superseded by this transaction */
1487 #define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1488 #define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1491 extern int jbd_blocks_per_page(struct inode *inode);
1493 /* JBD uses a CRC32 checksum */
1494 #define JBD_MAX_CHECKSUM_SIZE 4
1496 static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
1497 const void *address, unsigned int length)
1500 struct shash_desc shash;
1501 char ctx[JBD_MAX_CHECKSUM_SIZE];
1505 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
1506 JBD_MAX_CHECKSUM_SIZE);
1508 desc.shash.tfm = journal->j_chksum_driver;
1509 desc.shash.flags = 0;
1510 *(u32 *)desc.ctx = crc;
1512 err = crypto_shash_update(&desc.shash, address, length);
1515 return *(u32 *)desc.ctx;
1518 /* Return most recent uncommitted transaction */
1519 static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
1523 read_lock(&journal->j_state_lock);
1524 tid = journal->j_commit_request;
1525 if (journal->j_running_transaction)
1526 tid = journal->j_running_transaction->t_tid;
1527 read_unlock(&journal->j_state_lock);
1533 #define buffer_trace_init(bh) do {} while (0)
1534 #define print_buffer_fields(bh) do {} while (0)
1535 #define print_buffer_trace(bh) do {} while (0)
1536 #define BUFFER_TRACE(bh, info) do {} while (0)
1537 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1538 #define JBUFFER_TRACE(jh, info) do {} while (0)
1540 #endif /* __KERNEL__ */
1542 #define EFSBADCRC EBADMSG /* Bad CRC detected */
1543 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
1545 #endif /* _LINUX_JBD2_H */