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
113 * The block tag: used to describe a single buffer in the journal
115 typedef struct journal_block_tag_s
117 __u32 t_blocknr; /* The on-disk block number */
118 __u32 t_flags; /* See below */
119 } journal_block_tag_t;
122 * The revoke descriptor: used on disk to describe a series of blocks to
123 * be revoked from the log
125 typedef struct journal_revoke_header_s
127 journal_header_t r_header;
128 int r_count; /* Count of bytes used in the block */
129 } journal_revoke_header_t;
132 /* Definitions for the journal tag flags word: */
133 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
134 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
135 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
136 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
140 * The journal superblock. All fields are in big-endian byte order.
142 typedef struct journal_superblock_s
145 journal_header_t s_header;
148 /* Static information describing the journal */
149 __u32 s_blocksize; /* journal device blocksize */
150 __u32 s_maxlen; /* total blocks in journal file */
151 __u32 s_first; /* first block of log information */
154 /* Dynamic information describing the current state of the log */
155 __u32 s_sequence; /* first commit ID expected in log */
156 __u32 s_start; /* blocknr of start of log */
159 /* Error value, as set by journal_abort(). */
163 /* Remaining fields are only valid in a version-2 superblock */
164 __u32 s_feature_compat; /* compatible feature set */
165 __u32 s_feature_incompat; /* incompatible feature set */
166 __u32 s_feature_ro_compat; /* readonly-compatible feature set */
168 __u8 s_uuid[16]; /* 128-bit uuid for journal */
171 __u32 s_nr_users; /* Nr of filesystems sharing log */
173 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
176 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/
177 __u32 s_max_trans_data; /* Limit of data blocks per trans. */
183 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
185 } journal_superblock_t;
187 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
188 ((j)->j_format_version >= 2 && \
189 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
190 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
191 ((j)->j_format_version >= 2 && \
192 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
193 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
194 ((j)->j_format_version >= 2 && \
195 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
197 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
199 /* Features known to this kernel version: */
200 #define JFS_KNOWN_COMPAT_FEATURES 0
201 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
202 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
206 #include <linux/fs.h>
207 #include <linux/sched.h>
209 #define JBD_ASSERTIONS
210 #ifdef JBD_ASSERTIONS
211 #define J_ASSERT(assert) \
215 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
216 __FUNCTION__, __FILE__, __LINE__, # assert); \
221 #if defined(CONFIG_BUFFER_DEBUG)
222 void buffer_assertion_failure(struct buffer_head *bh);
223 #define J_ASSERT_BH(bh, expr) \
226 buffer_assertion_failure(bh); \
229 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
231 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
232 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
236 #define J_ASSERT(assert)
237 #endif /* JBD_ASSERTIONS */
239 enum jbd_state_bits {
241 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
242 BH_Freed, /* 1 if buffer has been freed (truncated) */
243 BH_Revoked, /* 1 if buffer has been revoked from the log */
244 BH_RevokeValid, /* 1 if buffer revoked flag is valid */
245 BH_JBDDirty, /* 1 if buffer is dirty but journaled */
248 /* Return true if the buffer is one which JBD is managing */
249 static inline int buffer_jbd(struct buffer_head *bh)
251 return __buffer_state(bh, JBD);
254 static inline struct buffer_head *jh2bh(struct journal_head *jh)
259 static inline struct journal_head *bh2jh(struct buffer_head *bh)
261 return bh->b_private;
264 struct jbd_revoke_table_s;
266 /* The handle_t type represents a single atomic update being performed
267 * by some process. All filesystem modifications made by the process go
268 * through this handle. Recursive operations (such as quota operations)
269 * are gathered into a single update.
271 * The buffer credits field is used to account for journaled buffers
272 * being modified by the running process. To ensure that there is
273 * enough log space for all outstanding operations, we need to limit the
274 * number of outstanding buffers possible at any time. When the
275 * operation completes, any buffer credits not used are credited back to
276 * the transaction, so that at all times we know how many buffers the
277 * outstanding updates on a transaction might possibly touch. */
281 /* Which compound transaction is this update a part of? */
282 transaction_t * h_transaction;
284 /* Number of remaining buffers we are allowed to dirty: */
285 int h_buffer_credits;
287 /* Reference count on this handle */
290 /* Field for caller's use to track errors through large fs
295 unsigned int h_sync: 1; /* sync-on-close */
296 unsigned int h_jdata: 1; /* force data journaling */
297 unsigned int h_aborted: 1; /* fatal error on handle */
301 /* The transaction_t type is the guts of the journaling mechanism. It
302 * tracks a compound transaction through its various states:
304 * RUNNING: accepting new updates
305 * LOCKED: Updates still running but we don't accept new ones
306 * RUNDOWN: Updates are tidying up but have finished requesting
307 * new buffers to modify (state not used for now)
308 * FLUSH: All updates complete, but we are still writing to disk
309 * COMMIT: All data on disk, writing commit record
310 * FINISHED: We still have to keep the transaction for checkpointing.
312 * The transaction keeps track of all of the buffers modified by a
313 * running transaction, and all of the buffers committed but not yet
314 * flushed to home for finished transactions.
319 /* Pointer to the journal for this transaction. */
320 journal_t * t_journal;
322 /* Sequence number for this transaction */
325 /* Transaction's current state */
335 /* Where in the log does this transaction's commit start? */
336 unsigned long t_log_start;
338 /* Doubly-linked circular list of all inodes owned by this
339 transaction */ /* AKPM: unused */
340 struct inode * t_ilist;
342 /* Number of buffers on the t_buffers list */
345 /* Doubly-linked circular list of all buffers reserved but not
346 yet modified by this transaction */
347 struct journal_head * t_reserved_list;
349 /* Doubly-linked circular list of all metadata buffers owned by this
351 struct journal_head * t_buffers;
354 * Doubly-linked circular list of all data buffers still to be
355 * flushed before this transaction can be committed.
356 * Protected by journal_datalist_lock.
358 struct journal_head * t_sync_datalist;
361 * Doubly-linked circular list of all writepage data buffers
362 * still to be written before this transaction can be committed.
363 * Protected by journal_datalist_lock.
365 struct journal_head * t_async_datalist;
367 /* Doubly-linked circular list of all forget buffers (superceded
368 buffers which we can un-checkpoint once this transaction
370 struct journal_head * t_forget;
373 * Doubly-linked circular list of all buffers still to be
374 * flushed before this transaction can be checkpointed.
376 /* Protected by journal_datalist_lock */
377 struct journal_head * t_checkpoint_list;
379 /* Doubly-linked circular list of temporary buffers currently
380 undergoing IO in the log */
381 struct journal_head * t_iobuf_list;
383 /* Doubly-linked circular list of metadata buffers being
384 shadowed by log IO. The IO buffers on the iobuf list and the
385 shadow buffers on this list match each other one for one at
387 struct journal_head * t_shadow_list;
389 /* Doubly-linked circular list of control buffers being written
391 struct journal_head * t_log_list;
393 /* Number of outstanding updates running on this transaction */
396 /* Number of buffers reserved for use by all handles in this
397 * transaction handle but not yet modified. */
398 int t_outstanding_credits;
401 * Forward and backward links for the circular list of all
402 * transactions awaiting checkpoint.
404 /* Protected by journal_datalist_lock */
405 transaction_t *t_cpnext, *t_cpprev;
407 /* When will the transaction expire (become due for commit), in
409 unsigned long t_expires;
411 /* How many handles used this transaction? */
416 /* The journal_t maintains all of the journaling state information for a
417 * single filesystem. It is linked to from the fs superblock structure.
419 * We use the journal_t to keep track of all outstanding transaction
420 * activity on the filesystem, and to manage the state of the log
421 * writing process. */
425 /* General journaling state flags */
426 unsigned long j_flags;
428 /* Is there an outstanding uncleared error on the journal (from
432 /* The superblock buffer */
433 struct buffer_head * j_sb_buffer;
434 journal_superblock_t * j_superblock;
436 /* Version of the superblock format */
437 int j_format_version;
439 /* Number of processes waiting to create a barrier lock */
442 /* The barrier lock itself */
443 struct semaphore j_barrier;
445 /* Transactions: The current running transaction... */
446 transaction_t * j_running_transaction;
448 /* ... the transaction we are pushing to disk ... */
449 transaction_t * j_committing_transaction;
451 /* ... and a linked circular list of all transactions waiting
452 * for checkpointing. */
453 /* Protected by journal_datalist_lock */
454 transaction_t * j_checkpoint_transactions;
456 /* Wait queue for waiting for a locked transaction to start
457 committing, or for a barrier lock to be released */
458 wait_queue_head_t j_wait_transaction_locked;
460 /* Wait queue for waiting for checkpointing to complete */
461 wait_queue_head_t j_wait_logspace;
463 /* Wait queue for waiting for commit to complete */
464 wait_queue_head_t j_wait_done_commit;
466 /* Wait queue to trigger checkpointing */
467 wait_queue_head_t j_wait_checkpoint;
469 /* Wait queue to trigger commit */
470 wait_queue_head_t j_wait_commit;
472 /* Wait queue to wait for updates to complete */
473 wait_queue_head_t j_wait_updates;
475 /* Semaphore for locking against concurrent checkpoints */
476 struct semaphore j_checkpoint_sem;
478 /* The main journal lock, used by lock_journal() */
479 struct semaphore j_sem;
481 /* Journal head: identifies the first unused block in the journal. */
482 unsigned long j_head;
484 /* Journal tail: identifies the oldest still-used block in the
486 unsigned long j_tail;
488 /* Journal free: how many free blocks are there in the journal? */
489 unsigned long j_free;
491 /* Journal start and end: the block numbers of the first usable
492 * block and one beyond the last usable block in the journal. */
493 unsigned long j_first, j_last;
495 /* Device, blocksize and starting block offset for the location
496 * where we store the journal. */
499 unsigned int j_blk_offset;
501 /* Device which holds the client fs. For internal journal this
502 * will be equal to j_dev. */
505 /* Total maximum capacity of the journal region on disk. */
506 unsigned int j_maxlen;
508 /* Optional inode where we store the journal. If present, all
509 * journal block numbers are mapped into this inode via
511 struct inode * j_inode;
513 /* Sequence number of the oldest transaction in the log */
514 tid_t j_tail_sequence;
515 /* Sequence number of the next transaction to grant */
516 tid_t j_transaction_sequence;
517 /* Sequence number of the most recently committed transaction */
518 tid_t j_commit_sequence;
519 /* Sequence number of the most recent transaction wanting commit */
520 tid_t j_commit_request;
522 /* Journal uuid: identifies the object (filesystem, LVM volume
523 * etc) backed by this journal. This will eventually be
524 * replaced by an array of uuids, allowing us to index multiple
525 * devices within a single journal and to perform atomic updates
530 /* Pointer to the current commit thread for this journal */
531 struct task_struct * j_task;
533 /* Maximum number of metadata buffers to allow in a single
534 * compound commit transaction */
535 int j_max_transaction_buffers;
537 /* What is the maximum transaction lifetime before we begin a
539 unsigned long j_commit_interval;
541 /* The timer used to wakeup the commit thread: */
542 struct timer_list * j_commit_timer;
543 int j_commit_timer_active;
545 /* Link all journals together - system-wide */
546 struct list_head j_all_journals;
548 /* The revoke table: maintains the list of revoked blocks in the
549 current transaction. */
550 struct jbd_revoke_table_s *j_revoke;
554 * Journal flag definitions
556 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
557 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
558 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
559 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
560 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
563 * Function declarations for the journaling transaction and buffer
568 extern void __journal_unfile_buffer(struct journal_head *);
569 extern void journal_unfile_buffer(struct journal_head *);
570 extern void __journal_refile_buffer(struct journal_head *);
571 extern void journal_refile_buffer(struct journal_head *);
572 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
573 extern void __journal_free_buffer(struct journal_head *bh);
574 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
575 extern void __journal_clean_data_list(transaction_t *transaction);
577 /* Log buffer allocation */
578 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
579 extern unsigned long journal_next_log_block(journal_t *);
581 /* Commit management */
582 extern void journal_commit_transaction(journal_t *);
584 /* Checkpoint list management */
585 int __journal_clean_checkpoint_list(journal_t *journal);
586 extern void journal_remove_checkpoint(struct journal_head *);
587 extern void __journal_remove_checkpoint(struct journal_head *);
588 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
589 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
593 journal_write_metadata_buffer(transaction_t *transaction,
594 struct journal_head *jh_in,
595 struct journal_head **jh_out,
598 /* Transaction locking */
599 extern void __wait_on_journal (journal_t *);
604 * We need to lock the journal during transaction state changes so that
605 * nobody ever tries to take a handle on the running transaction while
606 * we are in the middle of moving it to the commit phase.
608 * Note that the locking is completely interrupt unsafe. We never touch
609 * journal structures from interrupts.
611 * In 2.2, the BKL was required for lock_journal. This is no longer
615 static inline void lock_journal(journal_t *journal)
617 down(&journal->j_sem);
620 /* This returns zero if we acquired the semaphore */
621 static inline int try_lock_journal(journal_t * journal)
623 return down_trylock(&journal->j_sem);
626 static inline void unlock_journal(journal_t * journal)
632 static inline handle_t *journal_current_handle(void)
634 return current->journal_info;
637 /* The journaling code user interface:
639 * Create and destroy handles
640 * Register buffer modifications against the current transaction.
643 extern handle_t *journal_start(journal_t *, int nblocks);
644 extern handle_t *journal_try_start(journal_t *, int nblocks);
645 extern int journal_restart (handle_t *, int nblocks);
646 extern int journal_extend (handle_t *, int nblocks);
647 extern int journal_get_write_access (handle_t *, struct buffer_head *);
648 extern int journal_get_create_access (handle_t *, struct buffer_head *);
649 extern int journal_get_undo_access (handle_t *, struct buffer_head *);
650 extern int journal_dirty_data (handle_t *,
651 struct buffer_head *, int async);
652 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
653 extern void journal_release_buffer (handle_t *, struct buffer_head *);
654 extern void journal_forget (handle_t *, struct buffer_head *);
655 extern void journal_sync_buffer (struct buffer_head *);
656 extern int journal_flushpage(journal_t *, struct page *, unsigned long);
657 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
658 extern int journal_stop(handle_t *);
659 extern int journal_flush (journal_t *);
661 extern void journal_lock_updates (journal_t *);
662 extern void journal_unlock_updates (journal_t *);
664 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
665 int start, int len, int bsize);
666 extern journal_t * journal_init_inode (struct inode *);
667 extern int journal_update_format (journal_t *);
668 extern int journal_check_used_features
669 (journal_t *, unsigned long, unsigned long, unsigned long);
670 extern int journal_check_available_features
671 (journal_t *, unsigned long, unsigned long, unsigned long);
672 extern int journal_set_features
673 (journal_t *, unsigned long, unsigned long, unsigned long);
674 extern int journal_create (journal_t *);
675 extern int journal_load (journal_t *journal);
676 extern void journal_destroy (journal_t *);
677 extern int journal_recover (journal_t *journal);
678 extern int journal_wipe (journal_t *, int);
679 extern int journal_skip_recovery (journal_t *);
680 extern void journal_update_superblock (journal_t *, int);
681 extern void __journal_abort (journal_t *);
682 extern void journal_abort (journal_t *, int);
683 extern int journal_errno (journal_t *);
684 extern void journal_ack_err (journal_t *);
685 extern int journal_clear_err (journal_t *);
686 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
687 extern int journal_force_commit(journal_t *journal);
690 * journal_head management
692 extern struct journal_head
693 *journal_add_journal_head(struct buffer_head *bh);
694 extern void journal_remove_journal_head(struct buffer_head *bh);
695 extern void __journal_remove_journal_head(struct buffer_head *bh);
696 extern void journal_unlock_journal_head(struct journal_head *jh);
698 /* Primary revoke support */
699 #define JOURNAL_REVOKE_DEFAULT_HASH 256
700 extern int journal_init_revoke(journal_t *, int);
701 extern void journal_destroy_revoke_caches(void);
702 extern int journal_init_revoke_caches(void);
704 extern void journal_destroy_revoke(journal_t *);
705 extern int journal_revoke (handle_t *,
706 unsigned long, struct buffer_head *);
707 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
708 extern void journal_write_revoke_records(journal_t *, transaction_t *);
710 /* Recovery revoke support */
711 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
712 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
713 extern void journal_clear_revoke(journal_t *);
714 extern void journal_brelse_array(struct buffer_head *b[], int n);
716 /* The log thread user interface:
718 * Request space in the current transaction, and force transaction commit
719 * transitions on demand.
722 extern int log_space_left (journal_t *); /* Called with journal locked */
723 extern tid_t log_start_commit (journal_t *, transaction_t *);
724 extern void log_wait_commit (journal_t *, tid_t);
725 extern int log_do_checkpoint (journal_t *, int);
727 extern void log_wait_for_space(journal_t *, int nblocks);
728 extern void __journal_drop_transaction(journal_t *, transaction_t *);
729 extern int cleanup_journal_tail(journal_t *);
731 /* Reduce journal memory usage by flushing */
732 extern void shrink_journal_memory(void);
734 /* Debugging code only: */
736 #define jbd_ENOSYS() \
738 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
739 current->state = TASK_UNINTERRUPTIBLE; \
746 * Simple test wrapper function to test the JFS_ABORT state flag. This
747 * bit, when set, indicates that we have had a fatal error somewhere,
748 * either inside the journaling layer or indicated to us by the client
749 * (eg. ext3), and that we and should not commit any further
753 static inline int is_journal_aborted(journal_t *journal)
755 return journal->j_flags & JFS_ABORT;
758 static inline int is_handle_aborted(handle_t *handle)
760 if (handle->h_aborted)
762 return is_journal_aborted(handle->h_transaction->t_journal);
765 static inline void journal_abort_handle(handle_t *handle)
767 handle->h_aborted = 1;
770 /* Not all architectures define BUG() */
773 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
774 * ((char *) 0) = 0; \
780 extern int journal_recover (journal_t *journal);
781 extern int journal_skip_recovery (journal_t *);
783 /* Primary revoke support */
784 extern int journal_init_revoke(journal_t *, int);
785 extern void journal_destroy_revoke_caches(void);
786 extern int journal_init_revoke_caches(void);
788 /* Recovery revoke support */
789 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
790 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
791 extern void journal_clear_revoke(journal_t *);
792 extern void journal_brelse_array(struct buffer_head *b[], int n);
794 extern void journal_destroy_revoke(journal_t *);
795 #endif /* __KERNEL__ */
797 /* Comparison functions for transaction IDs: perform comparisons using
798 * modulo arithmetic so that they work over sequence number wraps. */
800 static inline int tid_gt(tid_t x, tid_t y)
802 int difference = (x - y);
803 return (difference > 0);
806 static inline int tid_geq(tid_t x, tid_t y)
808 int difference = (x - y);
809 return (difference >= 0);
812 extern int journal_blocks_per_page(struct inode *inode);
815 * Definitions which augment the buffer_head layer
818 /* journaling buffer types */
819 #define BJ_None 0 /* Not journaled */
820 #define BJ_SyncData 1 /* Normal data: flush before commit */
821 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */
822 #define BJ_Metadata 3 /* Normal journaled metadata */
823 #define BJ_Forget 4 /* Buffer superceded by this transaction */
824 #define BJ_IO 5 /* Buffer is for temporary IO use */
825 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
826 #define BJ_LogCtl 7 /* Buffer contains log descriptors */
827 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */
830 extern int jbd_blocks_per_page(struct inode *inode);
834 extern spinlock_t jh_splice_lock;
836 * Once `expr1' has been found true, take jh_splice_lock
837 * and then reevaluate everything.
839 #define SPLICE_LOCK(expr1, expr2) \
843 spin_lock(&jh_splice_lock); \
844 ret = (expr1) && (expr2); \
845 spin_unlock(&jh_splice_lock); \
851 * A number of buffer state predicates. They test for
852 * buffer_jbd() because they are used in core kernel code.
854 * These will be racy on SMP unless we're *sure* that the
855 * buffer won't be detached from the journalling system
859 /* Return true if the buffer is on journal list `list' */
860 static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
862 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
865 /* Return true if this bufer is dirty wrt the journal */
866 static inline int buffer_jdirty(struct buffer_head *bh)
868 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
871 /* Return true if it's a data buffer which journalling is managing */
872 static inline int buffer_jbd_data(struct buffer_head *bh)
874 return SPLICE_LOCK(buffer_jbd(bh),
875 bh2jh(bh)->b_jlist == BJ_SyncData ||
876 bh2jh(bh)->b_jlist == BJ_AsyncData);
880 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
882 #define assert_spin_locked(lock) do {} while(0)
885 #define buffer_trace_init(bh) do {} while (0)
886 #define print_buffer_fields(bh) do {} while (0)
887 #define print_buffer_trace(bh) do {} while (0)
888 #define BUFFER_TRACE(bh, info) do {} while (0)
889 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
890 #define JBUFFER_TRACE(jh, info) do {} while (0)
892 #endif /* __KERNEL__ */
894 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
897 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
901 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
903 #define J_ASSERT(expr) do {} while (0)
904 #define J_ASSERT_BH(bh, expr) do {} while (0)
905 #define buffer_jbd(bh) 0
906 #define buffer_jlist_eq(bh, val) 0
907 #define journal_buffer_journal_lru(bh) 0
909 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
910 #endif /* _LINUX_JBD_H */