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
118 #define JBD2_CRC32_CHKSUM_SIZE 4
120 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
122 * Commit block header for storing transactional checksums:
124 struct commit_header {
128 unsigned char h_chksum_type;
129 unsigned char h_chksum_size;
130 unsigned char h_padding[2];
131 __u32 h_chksum[JBD2_CHECKSUM_BYTES];
137 * The block tag: used to describe a single buffer in the journal
139 typedef struct journal_block_tag_s
141 __u32 t_blocknr; /* The on-disk block number */
142 __u32 t_flags; /* See below */
143 __u32 t_blocknr_high; /* most-significant high 32bits. */
144 } journal_block_tag_t;
146 #define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
147 #define JBD_TAG_SIZE32 (8)
150 * The revoke descriptor: used on disk to describe a series of blocks to
151 * be revoked from the log
153 typedef struct journal_revoke_header_s
155 journal_header_t r_header;
156 int r_count; /* Count of bytes used in the block */
157 } journal_revoke_header_t;
160 /* Definitions for the journal tag flags word: */
161 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
162 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
163 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
164 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
168 * The journal superblock. All fields are in big-endian byte order.
170 typedef struct journal_superblock_s
173 journal_header_t s_header;
176 /* Static information describing the journal */
177 __u32 s_blocksize; /* journal device blocksize */
178 __u32 s_maxlen; /* total blocks in journal file */
179 __u32 s_first; /* first block of log information */
182 /* Dynamic information describing the current state of the log */
183 __u32 s_sequence; /* first commit ID expected in log */
184 __u32 s_start; /* blocknr of start of log */
187 /* Error value, as set by journal_abort(). */
191 /* Remaining fields are only valid in a version-2 superblock */
192 __u32 s_feature_compat; /* compatible feature set */
193 __u32 s_feature_incompat; /* incompatible feature set */
194 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
196 __u8 s_uuid[16]; /* 128-bit uuid for journal */
199 __u32 s_nr_users; /* Nr of filesystems sharing log */
201 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
204 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
205 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
211 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
213 } journal_superblock_t;
215 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
216 ((j)->j_format_version >= 2 && \
217 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
218 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
219 ((j)->j_format_version >= 2 && \
220 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
221 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
222 ((j)->j_format_version >= 2 && \
223 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
225 #define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001
227 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
229 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
230 #define JFS_FEATURE_INCOMPAT_64BIT 0x00000002
231 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
233 /* Features known to this kernel version: */
234 #define JFS_KNOWN_COMPAT_FEATURES 0
235 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
236 #define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE|\
237 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT)
241 #include <linux/fs.h>
242 #include <linux/sched.h>
244 #define JBD_ASSERTIONS
245 #ifdef JBD_ASSERTIONS
246 #define J_ASSERT(assert) \
250 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
251 __FUNCTION__, __FILE__, __LINE__, # assert); \
256 #if defined(CONFIG_BUFFER_DEBUG)
257 void buffer_assertion_failure(struct buffer_head *bh);
258 #define J_ASSERT_BH(bh, expr) \
261 buffer_assertion_failure(bh); \
264 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
266 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
267 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
271 #define J_ASSERT(assert)
272 #endif /* JBD_ASSERTIONS */
274 enum jbd_state_bits {
276 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
277 BH_Freed, /* 1 if buffer has been freed (truncated) */
278 BH_Revoked, /* 1 if buffer has been revoked from the log */
279 BH_RevokeValid, /* 1 if buffer revoked flag is valid */
280 BH_JBDDirty, /* 1 if buffer is dirty but journaled */
283 /* Return true if the buffer is one which JBD is managing */
284 static inline int buffer_jbd(struct buffer_head *bh)
286 return __buffer_state(bh, JBD);
289 static inline struct buffer_head *jh2bh(struct journal_head *jh)
294 static inline struct journal_head *bh2jh(struct buffer_head *bh)
296 return bh->b_private;
299 struct jbd_revoke_table_s;
301 /* The handle_t type represents a single atomic update being performed
302 * by some process. All filesystem modifications made by the process go
303 * through this handle. Recursive operations (such as quota operations)
304 * are gathered into a single update.
306 * The buffer credits field is used to account for journaled buffers
307 * being modified by the running process. To ensure that there is
308 * enough log space for all outstanding operations, we need to limit the
309 * number of outstanding buffers possible at any time. When the
310 * operation completes, any buffer credits not used are credited back to
311 * the transaction, so that at all times we know how many buffers the
312 * outstanding updates on a transaction might possibly touch. */
316 /* Which compound transaction is this update a part of? */
317 transaction_t * h_transaction;
319 /* Number of remaining buffers we are allowed to dirty: */
320 int h_buffer_credits;
322 /* Reference count on this handle */
325 /* Field for caller's use to track errors through large fs
330 unsigned int h_sync: 1; /* sync-on-close */
331 unsigned int h_jdata: 1; /* force data journaling */
332 unsigned int h_aborted: 1; /* fatal error on handle */
336 /* The transaction_t type is the guts of the journaling mechanism. It
337 * tracks a compound transaction through its various states:
339 * RUNNING: accepting new updates
340 * LOCKED: Updates still running but we don't accept new ones
341 * RUNDOWN: Updates are tidying up but have finished requesting
342 * new buffers to modify (state not used for now)
343 * FLUSH: All updates complete, but we are still writing to disk
344 * COMMIT: All data on disk, writing commit record
345 * FINISHED: We still have to keep the transaction for checkpointing.
347 * The transaction keeps track of all of the buffers modified by a
348 * running transaction, and all of the buffers committed but not yet
349 * flushed to home for finished transactions.
354 /* Pointer to the journal for this transaction. */
355 journal_t * t_journal;
357 /* Sequence number for this transaction */
360 /* Transaction's current state */
370 /* Where in the log does this transaction's commit start? */
371 unsigned long t_log_start;
373 /* Doubly-linked circular list of all inodes owned by this
374 transaction */ /* AKPM: unused */
375 struct inode * t_ilist;
377 /* Number of buffers on the t_buffers list */
380 /* Doubly-linked circular list of all buffers reserved but not
381 yet modified by this transaction */
382 struct journal_head * t_reserved_list;
384 /* Doubly-linked circular list of all metadata buffers owned by this
386 struct journal_head * t_buffers;
389 * Doubly-linked circular list of all data buffers still to be
390 * flushed before this transaction can be committed.
391 * Protected by journal_datalist_lock.
393 struct journal_head * t_sync_datalist;
396 * Doubly-linked circular list of all writepage data buffers
397 * still to be written before this transaction can be committed.
398 * Protected by journal_datalist_lock.
400 struct journal_head * t_async_datalist;
402 /* Doubly-linked circular list of all forget buffers (superceded
403 buffers which we can un-checkpoint once this transaction
405 struct journal_head * t_forget;
408 * Doubly-linked circular list of all buffers still to be
409 * flushed before this transaction can be checkpointed.
411 /* Protected by journal_datalist_lock */
412 struct journal_head * t_checkpoint_list;
414 /* Doubly-linked circular list of temporary buffers currently
415 undergoing IO in the log */
416 struct journal_head * t_iobuf_list;
418 /* Doubly-linked circular list of metadata buffers being
419 shadowed by log IO. The IO buffers on the iobuf list and the
420 shadow buffers on this list match each other one for one at
422 struct journal_head * t_shadow_list;
424 /* Doubly-linked circular list of control buffers being written
426 struct journal_head * t_log_list;
428 /* Number of outstanding updates running on this transaction */
431 /* Number of buffers reserved for use by all handles in this
432 * transaction handle but not yet modified. */
433 int t_outstanding_credits;
436 * Forward and backward links for the circular list of all
437 * transactions awaiting checkpoint.
439 /* Protected by journal_datalist_lock */
440 transaction_t *t_cpnext, *t_cpprev;
442 /* When will the transaction expire (become due for commit), in
444 unsigned long t_expires;
446 /* How many handles used this transaction? */
451 /* The journal_t maintains all of the journaling state information for a
452 * single filesystem. It is linked to from the fs superblock structure.
454 * We use the journal_t to keep track of all outstanding transaction
455 * activity on the filesystem, and to manage the state of the log
456 * writing process. */
460 /* General journaling state flags */
461 unsigned long j_flags;
463 /* Is there an outstanding uncleared error on the journal (from
467 /* The superblock buffer */
468 struct buffer_head * j_sb_buffer;
469 journal_superblock_t * j_superblock;
471 /* Version of the superblock format */
472 int j_format_version;
474 /* Number of processes waiting to create a barrier lock */
477 /* The barrier lock itself */
478 struct semaphore j_barrier;
480 /* Transactions: The current running transaction... */
481 transaction_t * j_running_transaction;
483 /* ... the transaction we are pushing to disk ... */
484 transaction_t * j_committing_transaction;
486 /* ... and a linked circular list of all transactions waiting
487 * for checkpointing. */
488 /* Protected by journal_datalist_lock */
489 transaction_t * j_checkpoint_transactions;
491 /* Wait queue for waiting for a locked transaction to start
492 committing, or for a barrier lock to be released */
493 wait_queue_head_t j_wait_transaction_locked;
495 /* Wait queue for waiting for checkpointing to complete */
496 wait_queue_head_t j_wait_logspace;
498 /* Wait queue for waiting for commit to complete */
499 wait_queue_head_t j_wait_done_commit;
501 /* Wait queue to trigger checkpointing */
502 wait_queue_head_t j_wait_checkpoint;
504 /* Wait queue to trigger commit */
505 wait_queue_head_t j_wait_commit;
507 /* Wait queue to wait for updates to complete */
508 wait_queue_head_t j_wait_updates;
510 /* Semaphore for locking against concurrent checkpoints */
511 struct semaphore j_checkpoint_sem;
513 /* The main journal lock, used by lock_journal() */
514 struct semaphore j_sem;
516 /* Journal head: identifies the first unused block in the journal. */
517 unsigned long j_head;
519 /* Journal tail: identifies the oldest still-used block in the
521 unsigned long j_tail;
523 /* Journal free: how many free blocks are there in the journal? */
524 unsigned long j_free;
526 /* Journal start and end: the block numbers of the first usable
527 * block and one beyond the last usable block in the journal. */
528 unsigned long j_first, j_last;
530 /* Device, blocksize and starting block offset for the location
531 * where we store the journal. */
534 unsigned int j_blk_offset;
536 /* Device which holds the client fs. For internal journal this
537 * will be equal to j_dev. */
540 /* Total maximum capacity of the journal region on disk. */
541 unsigned int j_maxlen;
543 /* Optional inode where we store the journal. If present, all
544 * journal block numbers are mapped into this inode via
546 struct inode * j_inode;
548 /* Sequence number of the oldest transaction in the log */
549 tid_t j_tail_sequence;
550 /* Sequence number of the next transaction to grant */
551 tid_t j_transaction_sequence;
552 /* Sequence number of the most recently committed transaction */
553 tid_t j_commit_sequence;
554 /* Sequence number of the most recent transaction wanting commit */
555 tid_t j_commit_request;
557 /* Journal uuid: identifies the object (filesystem, LVM volume
558 * etc) backed by this journal. This will eventually be
559 * replaced by an array of uuids, allowing us to index multiple
560 * devices within a single journal and to perform atomic updates
565 /* Pointer to the current commit thread for this journal */
566 struct task_struct * j_task;
568 /* Maximum number of metadata buffers to allow in a single
569 * compound commit transaction */
570 int j_max_transaction_buffers;
572 /* What is the maximum transaction lifetime before we begin a
574 unsigned long j_commit_interval;
576 /* The timer used to wakeup the commit thread: */
577 struct timer_list * j_commit_timer;
578 int j_commit_timer_active;
580 /* Link all journals together - system-wide */
581 struct list_head j_all_journals;
583 /* The revoke table: maintains the list of revoked blocks in the
584 current transaction. */
585 struct jbd_revoke_table_s *j_revoke;
587 /* Failed journal commit ID */
588 unsigned int j_failed_commit;
592 * Journal flag definitions
594 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
595 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
596 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
597 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
598 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
601 * Function declarations for the journaling transaction and buffer
606 extern void __journal_unfile_buffer(struct journal_head *);
607 extern void journal_unfile_buffer(struct journal_head *);
608 extern void __journal_refile_buffer(struct journal_head *);
609 extern void journal_refile_buffer(struct journal_head *);
610 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
611 extern void __journal_free_buffer(struct journal_head *bh);
612 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
613 extern void __journal_clean_data_list(transaction_t *transaction);
615 /* Log buffer allocation */
616 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
617 extern unsigned long journal_next_log_block(journal_t *);
619 /* Commit management */
620 extern void journal_commit_transaction(journal_t *);
622 /* Checkpoint list management */
623 int __journal_clean_checkpoint_list(journal_t *journal);
624 extern void journal_remove_checkpoint(struct journal_head *);
625 extern void __journal_remove_checkpoint(struct journal_head *);
626 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
627 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
631 journal_write_metadata_buffer(transaction_t *transaction,
632 struct journal_head *jh_in,
633 struct journal_head **jh_out,
636 /* Transaction locking */
637 extern void __wait_on_journal (journal_t *);
642 * We need to lock the journal during transaction state changes so that
643 * nobody ever tries to take a handle on the running transaction while
644 * we are in the middle of moving it to the commit phase.
646 * Note that the locking is completely interrupt unsafe. We never touch
647 * journal structures from interrupts.
649 * In 2.2, the BKL was required for lock_journal. This is no longer
653 static inline void lock_journal(journal_t *journal)
655 down(&journal->j_sem);
658 /* This returns zero if we acquired the semaphore */
659 static inline int try_lock_journal(journal_t * journal)
661 return down_trylock(&journal->j_sem);
664 static inline void unlock_journal(journal_t * journal)
670 static inline handle_t *journal_current_handle(void)
672 return current->journal_info;
675 /* The journaling code user interface:
677 * Create and destroy handles
678 * Register buffer modifications against the current transaction.
681 extern handle_t *journal_start(journal_t *, int nblocks);
682 extern handle_t *journal_try_start(journal_t *, int nblocks);
683 extern int journal_restart (handle_t *, int nblocks);
684 extern int journal_extend (handle_t *, int nblocks);
685 extern int journal_get_write_access (handle_t *, struct buffer_head *);
686 extern int journal_get_create_access (handle_t *, struct buffer_head *);
687 extern int journal_get_undo_access (handle_t *, struct buffer_head *);
688 extern int journal_dirty_data (handle_t *,
689 struct buffer_head *, int async);
690 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
691 extern void journal_release_buffer (handle_t *, struct buffer_head *);
692 extern void journal_forget (handle_t *, struct buffer_head *);
693 extern void journal_sync_buffer (struct buffer_head *);
694 extern int journal_flushpage(journal_t *, struct page *, unsigned long);
695 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
696 extern int journal_stop(handle_t *);
697 extern int journal_flush (journal_t *);
699 extern void journal_lock_updates (journal_t *);
700 extern void journal_unlock_updates (journal_t *);
702 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
703 int start, int len, int bsize);
704 extern journal_t * journal_init_inode (struct inode *);
705 extern int journal_update_format (journal_t *);
706 extern int journal_check_used_features
707 (journal_t *, unsigned long, unsigned long, unsigned long);
708 extern int journal_check_available_features
709 (journal_t *, unsigned long, unsigned long, unsigned long);
710 extern int journal_set_features
711 (journal_t *, unsigned long, unsigned long, unsigned long);
712 extern int journal_create (journal_t *);
713 extern int journal_load (journal_t *journal);
714 extern void journal_destroy (journal_t *);
715 extern int journal_recover (journal_t *journal);
716 extern int journal_wipe (journal_t *, int);
717 extern int journal_skip_recovery (journal_t *);
718 extern void journal_update_superblock (journal_t *, int);
719 extern void __journal_abort (journal_t *);
720 extern void journal_abort (journal_t *, int);
721 extern int journal_errno (journal_t *);
722 extern void journal_ack_err (journal_t *);
723 extern int journal_clear_err (journal_t *);
724 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
725 extern int journal_force_commit(journal_t *journal);
728 * journal_head management
730 extern struct journal_head
731 *journal_add_journal_head(struct buffer_head *bh);
732 extern void journal_remove_journal_head(struct buffer_head *bh);
733 extern void __journal_remove_journal_head(struct buffer_head *bh);
734 extern void journal_unlock_journal_head(struct journal_head *jh);
736 /* Primary revoke support */
737 #define JOURNAL_REVOKE_DEFAULT_HASH 256
738 extern int journal_init_revoke(journal_t *, int);
739 extern void journal_destroy_revoke_caches(void);
740 extern int journal_init_revoke_caches(void);
742 extern void journal_destroy_revoke(journal_t *);
743 extern int journal_revoke (handle_t *,
744 unsigned long, struct buffer_head *);
745 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
746 extern void journal_write_revoke_records(journal_t *, transaction_t *);
748 /* Recovery revoke support */
749 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
750 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
751 extern void journal_clear_revoke(journal_t *);
752 extern void journal_brelse_array(struct buffer_head *b[], int n);
754 /* The log thread user interface:
756 * Request space in the current transaction, and force transaction commit
757 * transitions on demand.
760 extern int log_space_left (journal_t *); /* Called with journal locked */
761 extern tid_t log_start_commit (journal_t *, transaction_t *);
762 extern void log_wait_commit (journal_t *, tid_t);
763 extern int log_do_checkpoint (journal_t *, int);
765 extern void log_wait_for_space(journal_t *, int nblocks);
766 extern void __journal_drop_transaction(journal_t *, transaction_t *);
767 extern int cleanup_journal_tail(journal_t *);
769 /* Reduce journal memory usage by flushing */
770 extern void shrink_journal_memory(void);
772 /* Debugging code only: */
774 #define jbd_ENOSYS() \
776 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
777 current->state = TASK_UNINTERRUPTIBLE; \
784 * Simple test wrapper function to test the JFS_ABORT state flag. This
785 * bit, when set, indicates that we have had a fatal error somewhere,
786 * either inside the journaling layer or indicated to us by the client
787 * (eg. ext3), and that we and should not commit any further
791 static inline int is_journal_aborted(journal_t *journal)
793 return journal->j_flags & JFS_ABORT;
796 static inline int is_handle_aborted(handle_t *handle)
798 if (handle->h_aborted)
800 return is_journal_aborted(handle->h_transaction->t_journal);
803 static inline void journal_abort_handle(handle_t *handle)
805 handle->h_aborted = 1;
808 /* Not all architectures define BUG() */
811 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
812 * ((char *) 0) = 0; \
818 extern int journal_recover (journal_t *journal);
819 extern int journal_skip_recovery (journal_t *);
821 /* Primary revoke support */
822 extern int journal_init_revoke(journal_t *, int);
823 extern void journal_destroy_revoke_caches(void);
824 extern int journal_init_revoke_caches(void);
826 /* Recovery revoke support */
827 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
828 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
829 extern void journal_clear_revoke(journal_t *);
830 extern void journal_brelse_array(struct buffer_head *b[], int n);
832 extern void journal_destroy_revoke(journal_t *);
833 #endif /* __KERNEL__ */
835 static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused));
836 static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused));
838 /* Comparison functions for transaction IDs: perform comparisons using
839 * modulo arithmetic so that they work over sequence number wraps. */
841 static inline int tid_gt(tid_t x, tid_t y)
843 int difference = (x - y);
844 return (difference > 0);
847 static inline int tid_geq(tid_t x, tid_t y)
849 int difference = (x - y);
850 return (difference >= 0);
853 extern int journal_blocks_per_page(struct inode *inode);
856 * Definitions which augment the buffer_head layer
859 /* journaling buffer types */
860 #define BJ_None 0 /* Not journaled */
861 #define BJ_SyncData 1 /* Normal data: flush before commit */
862 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
863 #define BJ_Metadata 3 /* Normal journaled metadata */
864 #define BJ_Forget 4 /* Buffer superceded by this transaction */
865 #define BJ_IO 5 /* Buffer is for temporary IO use */
866 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
867 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
868 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
871 extern int jbd_blocks_per_page(struct inode *inode);
875 extern spinlock_t jh_splice_lock;
877 * Once `expr1' has been found true, take jh_splice_lock
878 * and then reevaluate everything.
880 #define SPLICE_LOCK(expr1, expr2) \
884 spin_lock(&jh_splice_lock); \
885 ret = (expr1) && (expr2); \
886 spin_unlock(&jh_splice_lock); \
892 * A number of buffer state predicates. They test for
893 * buffer_jbd() because they are used in core kernel code.
895 * These will be racy on SMP unless we're *sure* that the
896 * buffer won't be detached from the journalling system
900 /* Return true if the buffer is on journal list `list' */
901 static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
903 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
906 /* Return true if this bufer is dirty wrt the journal */
907 static inline int buffer_jdirty(struct buffer_head *bh)
909 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
912 /* Return true if it's a data buffer which journalling is managing */
913 static inline int buffer_jbd_data(struct buffer_head *bh)
915 return SPLICE_LOCK(buffer_jbd(bh),
916 bh2jh(bh)->b_jlist == BJ_SyncData ||
917 bh2jh(bh)->b_jlist == BJ_AsyncData);
921 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
923 #define assert_spin_locked(lock) do {} while(0)
926 #define buffer_trace_init(bh) do {} while (0)
927 #define print_buffer_fields(bh) do {} while (0)
928 #define print_buffer_trace(bh) do {} while (0)
929 #define BUFFER_TRACE(bh, info) do {} while (0)
930 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
931 #define JBUFFER_TRACE(jh, info) do {} while (0)
933 #endif /* __KERNEL__ */
935 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
938 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
942 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
944 #define J_ASSERT(expr) do {} while (0)
945 #define J_ASSERT_BH(bh, expr) do {} while (0)
946 #define buffer_jbd(bh) 0
947 #define buffer_jlist_eq(bh, val) 0
948 #define journal_buffer_journal_lru(bh) 0
950 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
951 #endif /* _LINUX_JBD_H */