2 * linux/include/linux/jbd.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 #if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__)
21 /* Allow this file to be included directly into e2fsprogs */
23 #include "jfs_compat.h"
25 #define jfs_debug jbd_debug
28 #include <linux/journal-head.h>
29 #include <linux/stddef.h>
30 #include <asm/semaphore.h>
34 #define __FUNCTION__ ""
37 #define journal_oom_retry 1
40 #ifdef CONFIG_JBD_DEBUG
42 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
43 * consistency checks. By default we don't do this unless
44 * CONFIG_JBD_DEBUG is on.
46 #define JBD_EXPENSIVE_CHECKING
47 extern int journal_enable_debug;
49 #define jbd_debug(n, f, a...) \
51 if ((n) <= journal_enable_debug) { \
52 printk (KERN_DEBUG "(%s, %d): %s: ", \
53 __FILE__, __LINE__, __FUNCTION__); \
59 #define jbd_debug(f, a...) /**/
61 #define jbd_debug(f, ...) /**/
65 #define jbd_debug(x) /* AIX doesn't do STDC */
68 extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry);
69 #define jbd_kmalloc(size, flags) \
70 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
71 #define jbd_rep_kmalloc(size, flags) \
72 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
74 #define JFS_MIN_JOURNAL_BLOCKS 1024
77 typedef struct handle_s handle_t; /* Atomic operation type */
78 typedef struct journal_s journal_t; /* Journal control structure */
82 * Internal structures used by the logging mechanism:
85 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
92 * Descriptor block types:
95 #define JFS_DESCRIPTOR_BLOCK 1
96 #define JFS_COMMIT_BLOCK 2
97 #define JFS_SUPERBLOCK_V1 3
98 #define JFS_SUPERBLOCK_V2 4
99 #define JFS_REVOKE_BLOCK 5
102 * Standard header for all descriptor blocks:
104 typedef struct journal_header_s
114 #define JBD2_CRC32_CHKSUM 1
115 #define JBD2_MD5_CHKSUM 2
116 #define JBD2_SHA1_CHKSUM 3
117 #define JBD2_CRC32C_CHKSUM 4
119 #define JBD2_CRC32_CHKSUM_SIZE 4
121 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
123 * Commit block header for storing transactional checksums:
125 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
126 * fields are used to store a checksum of the descriptor and data blocks.
128 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
129 * field is used to store crc32c(uuid+commit_block). Each journal metadata
130 * block gets its own checksum, and data block checksums are stored in
131 * journal_block_tag (in the descriptor). The other h_chksum* fields are
134 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
135 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
138 * Checksum v1, v2, and v3 are mutually exclusive features.
140 struct commit_header {
144 unsigned char h_chksum_type;
145 unsigned char h_chksum_size;
146 unsigned char h_padding[2];
147 __u32 h_chksum[JBD2_CHECKSUM_BYTES];
153 * The block tag: used to describe a single buffer in the journal
155 typedef struct journal_block_tag3_s
157 __u32 t_blocknr; /* The on-disk block number */
158 __u32 t_flags; /* See below */
159 __u32 t_blocknr_high; /* most-significant high 32bits. */
160 __u32 t_checksum; /* crc32c(uuid+seq+block) */
161 } journal_block_tag3_t;
163 typedef struct journal_block_tag_s
165 __u32 t_blocknr; /* The on-disk block number */
166 __u16 t_checksum; /* truncated crc32c(uuid+seq+block) */
167 __u16 t_flags; /* See below */
168 __u32 t_blocknr_high; /* most-significant high 32bits. */
169 } journal_block_tag_t;
171 /* Tail of descriptor block, for checksumming */
172 struct journal_block_tail {
177 * The revoke descriptor: used on disk to describe a series of blocks to
178 * be revoked from the log
180 typedef struct journal_revoke_header_s
182 journal_header_t r_header;
183 int r_count; /* Count of bytes used in the block */
184 } journal_revoke_header_t;
186 /* Tail of revoke block, for checksumming */
187 struct journal_revoke_tail {
191 /* Definitions for the journal tag flags word: */
192 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
193 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
194 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
195 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
199 #define JFS_USERS_MAX 48
200 #define JFS_USERS_SIZE (UUID_SIZE * JFS_USERS_MAX)
202 * The journal superblock. All fields are in big-endian byte order.
204 typedef struct journal_superblock_s
207 journal_header_t s_header;
210 /* Static information describing the journal */
211 __u32 s_blocksize; /* journal device blocksize */
212 __u32 s_maxlen; /* total blocks in journal file */
213 __u32 s_first; /* first block of log information */
216 /* Dynamic information describing the current state of the log */
217 __u32 s_sequence; /* first commit ID expected in log */
218 __u32 s_start; /* blocknr of start of log */
221 /* Error value, as set by journal_abort(). */
225 /* Remaining fields are only valid in a version-2 superblock */
226 __u32 s_feature_compat; /* compatible feature set */
227 __u32 s_feature_incompat; /* incompatible feature set */
228 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
230 __u8 s_uuid[16]; /* 128-bit uuid for journal */
233 __u32 s_nr_users; /* Nr of filesystems sharing log */
235 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
238 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
239 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
242 __u8 s_checksum_type; /* checksum type */
245 __u32 s_checksum; /* crc32c(superblock) */
248 __u8 s_users[JFS_USERS_SIZE]; /* ids of all fs'es sharing the log */
251 } journal_superblock_t;
253 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
254 ((j)->j_format_version >= 2 && \
255 ((j)->j_superblock->s_feature_compat & ext2fs_cpu_to_be32((mask))))
256 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
257 ((j)->j_format_version >= 2 && \
258 ((j)->j_superblock->s_feature_ro_compat & ext2fs_cpu_to_be32((mask))))
259 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
260 ((j)->j_format_version >= 2 && \
261 ((j)->j_superblock->s_feature_incompat & ext2fs_cpu_to_be32((mask))))
263 #define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001
265 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
266 #define JFS_FEATURE_INCOMPAT_64BIT 0x00000002
267 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
268 #define JFS_FEATURE_INCOMPAT_CSUM_V2 0x00000008
269 #define JFS_FEATURE_INCOMPAT_CSUM_V3 0x00000010
271 /* Features known to this kernel version: */
272 #define JFS_KNOWN_COMPAT_FEATURES 0
273 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
274 #define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE|\
275 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT|\
276 JFS_FEATURE_INCOMPAT_64BIT|\
277 JFS_FEATURE_INCOMPAT_CSUM_V2|\
278 JFS_FEATURE_INCOMPAT_CSUM_V3)
280 #if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
281 #ifdef E2FSCK_INCLUDE_INLINE_FUNCS
282 #if (__STDC_VERSION__ >= 199901L)
283 #define _INLINE_ extern inline
285 #define _INLINE_ inline
287 #else /* !E2FSCK_INCLUDE_INLINE FUNCS */
288 #if (__STDC_VERSION__ >= 199901L)
289 #define _INLINE_ inline
292 #define _INLINE_ extern __inline__
293 #else /* For Watcom C */
294 #define _INLINE_ extern inline
295 #endif /* __GNUC__ */
296 #endif /* __STDC_VERSION__ >= 199901L */
297 #endif /* INCLUDE_INLINE_FUNCS */
300 * helper functions to deal with 32 or 64bit block numbers.
302 _INLINE_ size_t journal_tag_bytes(journal_t *journal)
306 if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V3))
307 return sizeof(journal_block_tag3_t);
309 sz = sizeof(journal_block_tag_t);
311 if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
314 if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
317 return sz - sizeof(__u32);
320 _INLINE_ int journal_has_csum_v2or3(journal_t *journal)
322 if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2) ||
323 JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V3))
333 #include <linux/fs.h>
334 #include <linux/sched.h>
336 #define JBD_ASSERTIONS
337 #ifdef JBD_ASSERTIONS
338 #define J_ASSERT(assert) \
342 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
343 __FUNCTION__, __FILE__, __LINE__, # assert); \
348 #if defined(CONFIG_BUFFER_DEBUG)
349 void buffer_assertion_failure(struct buffer_head *bh);
350 #define J_ASSERT_BH(bh, expr) \
353 buffer_assertion_failure(bh); \
356 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
358 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
359 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
363 #define J_ASSERT(assert)
364 #endif /* JBD_ASSERTIONS */
366 enum jbd_state_bits {
368 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
369 BH_Freed, /* 1 if buffer has been freed (truncated) */
370 BH_Revoked, /* 1 if buffer has been revoked from the log */
371 BH_RevokeValid, /* 1 if buffer revoked flag is valid */
372 BH_JBDDirty, /* 1 if buffer is dirty but journaled */
375 /* Return true if the buffer is one which JBD is managing */
376 static inline int buffer_jbd(struct buffer_head *bh)
378 return __buffer_state(bh, JBD);
381 static inline struct buffer_head *jh2bh(struct journal_head *jh)
386 static inline struct journal_head *bh2jh(struct buffer_head *bh)
388 return bh->b_private;
391 struct jbd_revoke_table_s;
392 struct jbd2_revoke_table_s;
394 /* The handle_t type represents a single atomic update being performed
395 * by some process. All filesystem modifications made by the process go
396 * through this handle. Recursive operations (such as quota operations)
397 * are gathered into a single update.
399 * The buffer credits field is used to account for journaled buffers
400 * being modified by the running process. To ensure that there is
401 * enough log space for all outstanding operations, we need to limit the
402 * number of outstanding buffers possible at any time. When the
403 * operation completes, any buffer credits not used are credited back to
404 * the transaction, so that at all times we know how many buffers the
405 * outstanding updates on a transaction might possibly touch. */
409 /* Which compound transaction is this update a part of? */
410 transaction_t * h_transaction;
412 /* Number of remaining buffers we are allowed to dirty: */
413 int h_buffer_credits;
415 /* Reference count on this handle */
418 /* Field for caller's use to track errors through large fs
423 unsigned int h_sync: 1; /* sync-on-close */
424 unsigned int h_jdata: 1; /* force data journaling */
425 unsigned int h_aborted: 1; /* fatal error on handle */
429 /* The transaction_t type is the guts of the journaling mechanism. It
430 * tracks a compound transaction through its various states:
432 * RUNNING: accepting new updates
433 * LOCKED: Updates still running but we don't accept new ones
434 * RUNDOWN: Updates are tidying up but have finished requesting
435 * new buffers to modify (state not used for now)
436 * FLUSH: All updates complete, but we are still writing to disk
437 * COMMIT: All data on disk, writing commit record
438 * FINISHED: We still have to keep the transaction for checkpointing.
440 * The transaction keeps track of all of the buffers modified by a
441 * running transaction, and all of the buffers committed but not yet
442 * flushed to home for finished transactions.
447 /* Pointer to the journal for this transaction. */
448 journal_t * t_journal;
450 /* Sequence number for this transaction */
453 /* Transaction's current state */
463 /* Where in the log does this transaction's commit start? */
464 unsigned long t_log_start;
466 /* Doubly-linked circular list of all inodes owned by this
467 transaction */ /* AKPM: unused */
468 struct inode * t_ilist;
470 /* Number of buffers on the t_buffers list */
473 /* Doubly-linked circular list of all buffers reserved but not
474 yet modified by this transaction */
475 struct journal_head * t_reserved_list;
477 /* Doubly-linked circular list of all metadata buffers owned by this
479 struct journal_head * t_buffers;
482 * Doubly-linked circular list of all data buffers still to be
483 * flushed before this transaction can be committed.
484 * Protected by journal_datalist_lock.
486 struct journal_head * t_sync_datalist;
489 * Doubly-linked circular list of all writepage data buffers
490 * still to be written before this transaction can be committed.
491 * Protected by journal_datalist_lock.
493 struct journal_head * t_async_datalist;
495 /* Doubly-linked circular list of all forget buffers (superceded
496 buffers which we can un-checkpoint once this transaction
498 struct journal_head * t_forget;
501 * Doubly-linked circular list of all buffers still to be
502 * flushed before this transaction can be checkpointed.
504 /* Protected by journal_datalist_lock */
505 struct journal_head * t_checkpoint_list;
507 /* Doubly-linked circular list of temporary buffers currently
508 undergoing IO in the log */
509 struct journal_head * t_iobuf_list;
511 /* Doubly-linked circular list of metadata buffers being
512 shadowed by log IO. The IO buffers on the iobuf list and the
513 shadow buffers on this list match each other one for one at
515 struct journal_head * t_shadow_list;
517 /* Doubly-linked circular list of control buffers being written
519 struct journal_head * t_log_list;
521 /* Number of outstanding updates running on this transaction */
524 /* Number of buffers reserved for use by all handles in this
525 * transaction handle but not yet modified. */
526 int t_outstanding_credits;
529 * Forward and backward links for the circular list of all
530 * transactions awaiting checkpoint.
532 /* Protected by journal_datalist_lock */
533 transaction_t *t_cpnext, *t_cpprev;
535 /* When will the transaction expire (become due for commit), in
537 unsigned long t_expires;
539 /* How many handles used this transaction? */
544 /* The journal_t maintains all of the journaling state information for a
545 * single filesystem. It is linked to from the fs superblock structure.
547 * We use the journal_t to keep track of all outstanding transaction
548 * activity on the filesystem, and to manage the state of the log
549 * writing process. */
553 /* General journaling state flags */
554 unsigned long j_flags;
556 /* Is there an outstanding uncleared error on the journal (from
560 /* The superblock buffer */
561 struct buffer_head * j_sb_buffer;
562 journal_superblock_t * j_superblock;
564 /* Version of the superblock format */
565 int j_format_version;
567 /* Number of processes waiting to create a barrier lock */
570 /* The barrier lock itself */
571 struct semaphore j_barrier;
573 /* Transactions: The current running transaction... */
574 transaction_t * j_running_transaction;
576 /* ... the transaction we are pushing to disk ... */
577 transaction_t * j_committing_transaction;
579 /* ... and a linked circular list of all transactions waiting
580 * for checkpointing. */
581 /* Protected by journal_datalist_lock */
582 transaction_t * j_checkpoint_transactions;
584 /* Wait queue for waiting for a locked transaction to start
585 committing, or for a barrier lock to be released */
586 wait_queue_head_t j_wait_transaction_locked;
588 /* Wait queue for waiting for checkpointing to complete */
589 wait_queue_head_t j_wait_logspace;
591 /* Wait queue for waiting for commit to complete */
592 wait_queue_head_t j_wait_done_commit;
594 /* Wait queue to trigger checkpointing */
595 wait_queue_head_t j_wait_checkpoint;
597 /* Wait queue to trigger commit */
598 wait_queue_head_t j_wait_commit;
600 /* Wait queue to wait for updates to complete */
601 wait_queue_head_t j_wait_updates;
603 /* Semaphore for locking against concurrent checkpoints */
604 struct semaphore j_checkpoint_sem;
606 /* The main journal lock, used by lock_journal() */
607 struct semaphore j_sem;
609 /* Journal head: identifies the first unused block in the journal. */
610 unsigned long j_head;
612 /* Journal tail: identifies the oldest still-used block in the
614 unsigned long j_tail;
616 /* Journal free: how many free blocks are there in the journal? */
617 unsigned long j_free;
619 /* Journal start and end: the block numbers of the first usable
620 * block and one beyond the last usable block in the journal. */
621 unsigned long j_first, j_last;
623 /* Device, blocksize and starting block offset for the location
624 * where we store the journal. */
627 unsigned int j_blk_offset;
629 /* Device which holds the client fs. For internal journal this
630 * will be equal to j_dev. */
633 /* Total maximum capacity of the journal region on disk. */
634 unsigned int j_maxlen;
636 /* Optional inode where we store the journal. If present, all
637 * journal block numbers are mapped into this inode via
639 struct inode * j_inode;
641 /* Sequence number of the oldest transaction in the log */
642 tid_t j_tail_sequence;
643 /* Sequence number of the next transaction to grant */
644 tid_t j_transaction_sequence;
645 /* Sequence number of the most recently committed transaction */
646 tid_t j_commit_sequence;
647 /* Sequence number of the most recent transaction wanting commit */
648 tid_t j_commit_request;
650 /* Journal uuid: identifies the object (filesystem, LVM volume
651 * etc) backed by this journal. This will eventually be
652 * replaced by an array of uuids, allowing us to index multiple
653 * devices within a single journal and to perform atomic updates
658 /* Pointer to the current commit thread for this journal */
659 struct task_struct * j_task;
661 /* Maximum number of metadata buffers to allow in a single
662 * compound commit transaction */
663 int j_max_transaction_buffers;
665 /* What is the maximum transaction lifetime before we begin a
667 unsigned long j_commit_interval;
669 /* The timer used to wakeup the commit thread: */
670 struct timer_list * j_commit_timer;
671 int j_commit_timer_active;
673 /* Link all journals together - system-wide */
674 struct list_head j_all_journals;
676 /* The revoke table: maintains the list of revoked blocks in the
677 current transaction. */
678 struct jbd_revoke_table_s *j_revoke;
680 /* Failed journal commit ID */
681 unsigned int j_failed_commit;
685 * Journal flag definitions
687 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
688 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
689 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
690 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
691 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
694 * Function declarations for the journaling transaction and buffer
699 extern void __journal_unfile_buffer(struct journal_head *);
700 extern void journal_unfile_buffer(struct journal_head *);
701 extern void __journal_refile_buffer(struct journal_head *);
702 extern void journal_refile_buffer(struct journal_head *);
703 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
704 extern void __journal_free_buffer(struct journal_head *bh);
705 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
706 extern void __journal_clean_data_list(transaction_t *transaction);
708 /* Log buffer allocation */
709 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
710 extern unsigned long journal_next_log_block(journal_t *);
712 /* Commit management */
713 extern void journal_commit_transaction(journal_t *);
715 /* Checkpoint list management */
716 int __journal_clean_checkpoint_list(journal_t *journal);
717 extern void journal_remove_checkpoint(struct journal_head *);
718 extern void __journal_remove_checkpoint(struct journal_head *);
719 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
720 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
724 journal_write_metadata_buffer(transaction_t *transaction,
725 struct journal_head *jh_in,
726 struct journal_head **jh_out,
729 /* Transaction locking */
730 extern void __wait_on_journal (journal_t *);
735 * We need to lock the journal during transaction state changes so that
736 * nobody ever tries to take a handle on the running transaction while
737 * we are in the middle of moving it to the commit phase.
739 * Note that the locking is completely interrupt unsafe. We never touch
740 * journal structures from interrupts.
742 * In 2.2, the BKL was required for lock_journal. This is no longer
746 static inline void lock_journal(journal_t *journal)
748 down(&journal->j_sem);
751 /* This returns zero if we acquired the semaphore */
752 static inline int try_lock_journal(journal_t * journal)
754 return down_trylock(&journal->j_sem);
757 static inline void unlock_journal(journal_t * journal)
763 static inline handle_t *journal_current_handle(void)
765 return current->journal_info;
768 /* The journaling code user interface:
770 * Create and destroy handles
771 * Register buffer modifications against the current transaction.
774 extern handle_t *journal_start(journal_t *, int nblocks);
775 extern handle_t *journal_try_start(journal_t *, int nblocks);
776 extern int journal_restart (handle_t *, int nblocks);
777 extern int journal_extend (handle_t *, int nblocks);
778 extern int journal_get_write_access (handle_t *, struct buffer_head *);
779 extern int journal_get_create_access (handle_t *, struct buffer_head *);
780 extern int journal_get_undo_access (handle_t *, struct buffer_head *);
781 extern int journal_dirty_data (handle_t *,
782 struct buffer_head *, int async);
783 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
784 extern void journal_release_buffer (handle_t *, struct buffer_head *);
785 extern void journal_forget (handle_t *, struct buffer_head *);
786 extern void journal_sync_buffer (struct buffer_head *);
787 extern int journal_flushpage(journal_t *, struct page *, unsigned long);
788 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
789 extern int journal_stop(handle_t *);
790 extern int journal_flush (journal_t *);
792 extern void journal_lock_updates (journal_t *);
793 extern void journal_unlock_updates (journal_t *);
795 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
796 int start, int len, int bsize);
797 extern journal_t * journal_init_inode (struct inode *);
798 extern int journal_update_format (journal_t *);
799 extern int journal_check_used_features
800 (journal_t *, unsigned long, unsigned long, unsigned long);
801 extern int journal_check_available_features
802 (journal_t *, unsigned long, unsigned long, unsigned long);
803 extern int journal_set_features
804 (journal_t *, unsigned long, unsigned long, unsigned long);
805 extern int journal_create (journal_t *);
806 extern int journal_load (journal_t *journal);
807 extern void journal_destroy (journal_t *);
808 extern int journal_recover (journal_t *journal);
809 extern int journal_wipe (journal_t *, int);
810 extern int journal_skip_recovery (journal_t *);
811 extern void journal_update_superblock (journal_t *, int);
812 extern void __journal_abort (journal_t *);
813 extern void journal_abort (journal_t *, int);
814 extern int journal_errno (journal_t *);
815 extern void journal_ack_err (journal_t *);
816 extern int journal_clear_err (journal_t *);
817 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
818 extern int journal_force_commit(journal_t *journal);
821 * journal_head management
823 extern struct journal_head
824 *journal_add_journal_head(struct buffer_head *bh);
825 extern void journal_remove_journal_head(struct buffer_head *bh);
826 extern void __journal_remove_journal_head(struct buffer_head *bh);
827 extern void journal_unlock_journal_head(struct journal_head *jh);
829 /* Primary revoke support */
830 #define JOURNAL_REVOKE_DEFAULT_HASH 256
831 extern int journal_init_revoke(journal_t *, int);
832 extern void journal_destroy_revoke_caches(void);
833 extern int journal_init_revoke_caches(void);
835 extern void journal_destroy_revoke(journal_t *);
836 extern int journal_revoke (handle_t *,
837 unsigned long, struct buffer_head *);
838 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
839 extern void journal_write_revoke_records(journal_t *, transaction_t *);
841 /* Recovery revoke support */
842 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
843 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
844 extern void journal_clear_revoke(journal_t *);
845 extern void journal_brelse_array(struct buffer_head *b[], int n);
847 /* The log thread user interface:
849 * Request space in the current transaction, and force transaction commit
850 * transitions on demand.
853 extern int log_space_left (journal_t *); /* Called with journal locked */
854 extern tid_t log_start_commit (journal_t *, transaction_t *);
855 extern void log_wait_commit (journal_t *, tid_t);
856 extern int log_do_checkpoint (journal_t *, int);
858 extern void log_wait_for_space(journal_t *, int nblocks);
859 extern void __journal_drop_transaction(journal_t *, transaction_t *);
860 extern int cleanup_journal_tail(journal_t *);
862 /* Reduce journal memory usage by flushing */
863 extern void shrink_journal_memory(void);
865 /* Debugging code only: */
867 #define jbd_ENOSYS() \
869 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
870 current->state = TASK_UNINTERRUPTIBLE; \
877 * Simple test wrapper function to test the JFS_ABORT state flag. This
878 * bit, when set, indicates that we have had a fatal error somewhere,
879 * either inside the journaling layer or indicated to us by the client
880 * (eg. ext3), and that we and should not commit any further
884 static inline int is_journal_aborted(journal_t *journal)
886 return journal->j_flags & JFS_ABORT;
889 static inline int is_handle_aborted(handle_t *handle)
891 if (handle->h_aborted)
893 return is_journal_aborted(handle->h_transaction->t_journal);
896 static inline void journal_abort_handle(handle_t *handle)
898 handle->h_aborted = 1;
901 /* Not all architectures define BUG() */
904 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
905 * ((char *) 0) = 0; \
911 extern int journal_recover (journal_t *journal);
912 extern int journal_skip_recovery (journal_t *);
914 /* Primary revoke support */
915 extern int journal_init_revoke(journal_t *, int);
916 extern void journal_destroy_revoke_caches(void);
917 extern int journal_init_revoke_caches(void);
919 /* Recovery revoke support */
920 extern int journal_set_revoke(journal_t *, unsigned long long, tid_t);
921 extern int journal_test_revoke(journal_t *, unsigned long long, tid_t);
922 extern void journal_clear_revoke(journal_t *);
923 extern void journal_brelse_array(struct buffer_head *b[], int n);
925 extern void journal_destroy_revoke(journal_t *);
926 #endif /* __KERNEL__ */
928 static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused));
929 static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused));
931 /* Comparison functions for transaction IDs: perform comparisons using
932 * modulo arithmetic so that they work over sequence number wraps. */
934 static inline int tid_gt(tid_t x, tid_t y)
936 int difference = (x - y);
937 return (difference > 0);
940 static inline int tid_geq(tid_t x, tid_t y)
942 int difference = (x - y);
943 return (difference >= 0);
946 extern int journal_blocks_per_page(struct inode *inode);
949 * Definitions which augment the buffer_head layer
952 /* journaling buffer types */
953 #define BJ_None 0 /* Not journaled */
954 #define BJ_SyncData 1 /* Normal data: flush before commit */
955 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
956 #define BJ_Metadata 3 /* Normal journaled metadata */
957 #define BJ_Forget 4 /* Buffer superceded by this transaction */
958 #define BJ_IO 5 /* Buffer is for temporary IO use */
959 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
960 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
961 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
964 extern int jbd_blocks_per_page(struct inode *inode);
968 extern spinlock_t jh_splice_lock;
970 * Once `expr1' has been found true, take jh_splice_lock
971 * and then reevaluate everything.
973 #define SPLICE_LOCK(expr1, expr2) \
977 spin_lock(&jh_splice_lock); \
978 ret = (expr1) && (expr2); \
979 spin_unlock(&jh_splice_lock); \
985 * A number of buffer state predicates. They test for
986 * buffer_jbd() because they are used in core kernel code.
988 * These will be racy on SMP unless we're *sure* that the
989 * buffer won't be detached from the journalling system
993 /* Return true if the buffer is on journal list `list' */
994 static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
996 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
999 /* Return true if this bufer is dirty wrt the journal */
1000 static inline int buffer_jdirty(struct buffer_head *bh)
1002 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
1005 /* Return true if it's a data buffer which journalling is managing */
1006 static inline int buffer_jbd_data(struct buffer_head *bh)
1008 return SPLICE_LOCK(buffer_jbd(bh),
1009 bh2jh(bh)->b_jlist == BJ_SyncData ||
1010 bh2jh(bh)->b_jlist == BJ_AsyncData);
1014 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
1016 #define assert_spin_locked(lock) do {} while(0)
1019 #define buffer_trace_init(bh) do {} while (0)
1020 #define print_buffer_fields(bh) do {} while (0)
1021 #define print_buffer_trace(bh) do {} while (0)
1022 #define BUFFER_TRACE(bh, info) do {} while (0)
1023 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1024 #define JBUFFER_TRACE(jh, info) do {} while (0)
1026 #endif /* __KERNEL__ */
1028 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
1031 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
1035 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
1037 #define J_ASSERT(expr) do {} while (0)
1038 #define J_ASSERT_BH(bh, expr) do {} while (0)
1039 #define buffer_jbd(bh) 0
1040 #define buffer_jlist_eq(bh, val) 0
1041 #define journal_buffer_journal_lru(bh) 0
1043 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
1044 #endif /* _LINUX_JBD_H */