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 /* Allow this file to be included directly into e2fsprogs */
21 #include "jfs_compat.h"
23 #define jfs_debug jbd_debug
26 #include <linux/types.h>
27 #include <linux/buffer_head.h>
28 #include <linux/journal-head.h>
29 #include <linux/stddef.h>
30 #include <linux/bit_spinlock.h>
31 #include <linux/mutex.h>
32 #include <linux/timer.h>
33 #include <linux/lockdep.h>
35 #include <asm/semaphore.h>
38 #define journal_oom_retry 1
41 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
42 * certain classes of error which can occur due to failed IOs. Under
43 * normal use we want ext3 to continue after such errors, because
44 * hardware _can_ fail, but for debugging purposes when running tests on
45 * known-good hardware we may want to trap these errors.
47 #undef JBD_PARANOID_IOFAIL
50 * The default maximum commit age, in seconds.
52 #define JBD_DEFAULT_MAX_COMMIT_AGE 5
54 #ifdef CONFIG_JBD_DEBUG
56 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
57 * consistency checks. By default we don't do this unless
58 * CONFIG_JBD_DEBUG is on.
60 #define JBD_EXPENSIVE_CHECKING
61 extern int journal_enable_debug;
63 #define jbd_debug(n, f, a...) \
65 if ((n) <= journal_enable_debug) { \
66 printk (KERN_DEBUG "(%s, %d): %s: ", \
67 __FILE__, __LINE__, __FUNCTION__); \
72 #define jbd_debug(f, a...) /**/
75 extern void * __jbd_kmalloc (const char *where, size_t size, gfp_t flags, int retry);
76 #define jbd_kmalloc(size, flags) \
77 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
78 #define jbd_rep_kmalloc(size, flags) \
79 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
81 static inline void *jbd_alloc(size_t size, gfp_t flags)
83 return (void *)__get_free_pages(flags, get_order(size));
86 static inline void jbd_free(void *ptr, size_t size)
88 free_pages((unsigned long)ptr, get_order(size));
91 #define JFS_MIN_JOURNAL_BLOCKS 1024
96 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
98 * All filesystem modifications made by the process go
99 * through this handle. Recursive operations (such as quota operations)
100 * are gathered into a single update.
102 * The buffer credits field is used to account for journaled buffers
103 * being modified by the running process. To ensure that there is
104 * enough log space for all outstanding operations, we need to limit the
105 * number of outstanding buffers possible at any time. When the
106 * operation completes, any buffer credits not used are credited back to
107 * the transaction, so that at all times we know how many buffers the
108 * outstanding updates on a transaction might possibly touch.
110 * This is an opaque datatype.
112 typedef struct handle_s handle_t; /* Atomic operation type */
116 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
118 * journal_t is linked to from the fs superblock structure.
120 * We use the journal_t to keep track of all outstanding transaction
121 * activity on the filesystem, and to manage the state of the log
124 * This is an opaque datatype.
126 typedef struct journal_s journal_t; /* Journal control structure */
130 * Internal structures used by the logging mechanism:
133 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
140 * Descriptor block types:
143 #define JFS_DESCRIPTOR_BLOCK 1
144 #define JFS_COMMIT_BLOCK 2
145 #define JFS_SUPERBLOCK_V1 3
146 #define JFS_SUPERBLOCK_V2 4
147 #define JFS_REVOKE_BLOCK 5
150 * Standard header for all descriptor blocks:
152 typedef struct journal_header_s
161 * The block tag: used to describe a single buffer in the journal
163 typedef struct journal_block_tag_s
165 __be32 t_blocknr; /* The on-disk block number */
166 __be32 t_flags; /* See below */
167 } journal_block_tag_t;
170 * The revoke descriptor: used on disk to describe a series of blocks to
171 * be revoked from the log
173 typedef struct journal_revoke_header_s
175 journal_header_t r_header;
176 __be32 r_count; /* Count of bytes used in the block */
177 } journal_revoke_header_t;
180 /* Definitions for the journal tag flags word: */
181 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
182 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
183 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
184 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
188 * The journal superblock. All fields are in big-endian byte order.
190 typedef struct journal_superblock_s
193 journal_header_t s_header;
196 /* Static information describing the journal */
197 __be32 s_blocksize; /* journal device blocksize */
198 __be32 s_maxlen; /* total blocks in journal file */
199 __be32 s_first; /* first block of log information */
202 /* Dynamic information describing the current state of the log */
203 __be32 s_sequence; /* first commit ID expected in log */
204 __be32 s_start; /* blocknr of start of log */
207 /* Error value, as set by journal_abort(). */
211 /* Remaining fields are only valid in a version-2 superblock */
212 __be32 s_feature_compat; /* compatible feature set */
213 __be32 s_feature_incompat; /* incompatible feature set */
214 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
216 __u8 s_uuid[16]; /* 128-bit uuid for journal */
219 __be32 s_nr_users; /* Nr of filesystems sharing log */
221 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
224 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
225 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
231 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
233 } journal_superblock_t;
235 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
236 ((j)->j_format_version >= 2 && \
237 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
238 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
239 ((j)->j_format_version >= 2 && \
240 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
241 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
242 ((j)->j_format_version >= 2 && \
243 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
245 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
247 /* Features known to this kernel version: */
248 #define JFS_KNOWN_COMPAT_FEATURES 0
249 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
250 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
254 #include <linux/fs.h>
255 #include <linux/sched.h>
257 #define JBD_ASSERTIONS
258 #ifdef JBD_ASSERTIONS
259 #define J_ASSERT(assert) \
263 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
264 __FUNCTION__, __FILE__, __LINE__, # assert); \
269 #if defined(CONFIG_BUFFER_DEBUG)
270 void buffer_assertion_failure(struct buffer_head *bh);
271 #define J_ASSERT_BH(bh, expr) \
274 buffer_assertion_failure(bh); \
277 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
279 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
280 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
284 #define J_ASSERT(assert) do { } while (0)
285 #endif /* JBD_ASSERTIONS */
287 #if defined(JBD_PARANOID_IOFAIL)
288 #define J_EXPECT(expr, why...) J_ASSERT(expr)
289 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
290 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
292 #define __journal_expect(expr, why...) \
297 "EXT3-fs unexpected failure: %s;\n",# expr); \
298 printk(KERN_ERR why "\n"); \
302 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
303 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
304 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
307 enum jbd_state_bits {
308 BH_JBD /* Has an attached ext3 journal_head */
310 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
311 BH_Freed, /* Has been freed (truncated) */
312 BH_Revoked, /* Has been revoked from the log */
313 BH_RevokeValid, /* Revoked flag is valid */
314 BH_JBDDirty, /* Is dirty but journaled */
315 BH_State, /* Pins most journal_head state */
316 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
317 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
321 BUFFER_FNS(JWrite, jwrite)
322 BUFFER_FNS(JBDDirty, jbddirty)
323 TAS_BUFFER_FNS(JBDDirty, jbddirty)
324 BUFFER_FNS(Revoked, revoked)
325 TAS_BUFFER_FNS(Revoked, revoked)
326 BUFFER_FNS(RevokeValid, revokevalid)
327 TAS_BUFFER_FNS(RevokeValid, revokevalid)
328 BUFFER_FNS(Freed, freed)
330 static inline struct buffer_head *jh2bh(struct journal_head *jh)
335 static inline struct journal_head *bh2jh(struct buffer_head *bh)
337 return bh->b_private;
340 static inline void jbd_lock_bh_state(struct buffer_head *bh)
342 bit_spin_lock(BH_State, &bh->b_state);
345 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
347 return bit_spin_trylock(BH_State, &bh->b_state);
350 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
352 return bit_spin_is_locked(BH_State, &bh->b_state);
355 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
357 bit_spin_unlock(BH_State, &bh->b_state);
360 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
362 bit_spin_lock(BH_JournalHead, &bh->b_state);
365 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
367 bit_spin_unlock(BH_JournalHead, &bh->b_state);
370 struct jbd_revoke_table_s;
373 * struct handle_s - The handle_s type is the concrete type associated with
375 * @h_transaction: Which compound transaction is this update a part of?
376 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
377 * @h_ref: Reference count on this handle
378 * @h_err: Field for caller's use to track errors through large fs operations
379 * @h_sync: flag for sync-on-close
380 * @h_jdata: flag to force data journaling
381 * @h_aborted: flag indicating fatal error on handle
382 * @h_lockdep_map: lockdep info for debugging lock problems
385 /* Docbook can't yet cope with the bit fields, but will leave the documentation
386 * in so it can be fixed later.
391 /* Which compound transaction is this update a part of? */
392 transaction_t *h_transaction;
394 /* Number of remaining buffers we are allowed to dirty: */
395 int h_buffer_credits;
397 /* Reference count on this handle */
400 /* Field for caller's use to track errors through large fs */
404 /* Flags [no locking] */
405 unsigned int h_sync: 1; /* sync-on-close */
406 unsigned int h_jdata: 1; /* force data journaling */
407 unsigned int h_aborted: 1; /* fatal error on handle */
409 #ifdef CONFIG_DEBUG_LOCK_ALLOC
410 struct lockdep_map h_lockdep_map;
415 /* The transaction_t type is the guts of the journaling mechanism. It
416 * tracks a compound transaction through its various states:
418 * RUNNING: accepting new updates
419 * LOCKED: Updates still running but we don't accept new ones
420 * RUNDOWN: Updates are tidying up but have finished requesting
421 * new buffers to modify (state not used for now)
422 * FLUSH: All updates complete, but we are still writing to disk
423 * COMMIT: All data on disk, writing commit record
424 * FINISHED: We still have to keep the transaction for checkpointing.
426 * The transaction keeps track of all of the buffers modified by a
427 * running transaction, and all of the buffers committed but not yet
428 * flushed to home for finished transactions.
435 * ->jbd_lock_bh_journal_head() (This is "innermost")
438 * ->jbd_lock_bh_state()
440 * jbd_lock_bh_state()
447 * ->j_list_lock (journal_unmap_buffer)
453 /* Pointer to the journal for this transaction. [no locking] */
454 journal_t *t_journal;
456 /* Sequence number for this transaction [no locking] */
460 * Transaction's current state
461 * [no locking - only kjournald alters this]
462 * FIXME: needs barriers
463 * KLUDGE: [use j_state_lock]
475 * Where in the log does this transaction's commit start? [no locking]
477 unsigned long t_log_start;
479 /* Number of buffers on the t_buffers list [j_list_lock] */
483 * Doubly-linked circular list of all buffers reserved but not yet
484 * modified by this transaction [j_list_lock]
486 struct journal_head *t_reserved_list;
489 * Doubly-linked circular list of all buffers under writeout during
490 * commit [j_list_lock]
492 struct journal_head *t_locked_list;
495 * Doubly-linked circular list of all metadata buffers owned by this
496 * transaction [j_list_lock]
498 struct journal_head *t_buffers;
501 * Doubly-linked circular list of all data buffers still to be
502 * flushed before this transaction can be committed [j_list_lock]
504 struct journal_head *t_sync_datalist;
507 * Doubly-linked circular list of all forget buffers (superseded
508 * buffers which we can un-checkpoint once this transaction commits)
511 struct journal_head *t_forget;
514 * Doubly-linked circular list of all buffers still to be flushed before
515 * this transaction can be checkpointed. [j_list_lock]
517 struct journal_head *t_checkpoint_list;
520 * Doubly-linked circular list of all buffers submitted for IO while
521 * checkpointing. [j_list_lock]
523 struct journal_head *t_checkpoint_io_list;
526 * Doubly-linked circular list of temporary buffers currently undergoing
527 * IO in the log [j_list_lock]
529 struct journal_head *t_iobuf_list;
532 * Doubly-linked circular list of metadata buffers being shadowed by log
533 * IO. The IO buffers on the iobuf list and the shadow buffers on this
534 * list match each other one for one at all times. [j_list_lock]
536 struct journal_head *t_shadow_list;
539 * Doubly-linked circular list of control buffers being written to the
542 struct journal_head *t_log_list;
545 * Protects info related to handles
547 spinlock_t t_handle_lock;
550 * Number of outstanding updates running on this transaction
556 * Number of buffers reserved for use by all handles in this transaction
557 * handle but not yet modified. [t_handle_lock]
559 int t_outstanding_credits;
562 * Forward and backward links for the circular list of all transactions
563 * awaiting checkpoint. [j_list_lock]
565 transaction_t *t_cpnext, *t_cpprev;
568 * When will the transaction expire (become due for commit), in jiffies?
571 unsigned long t_expires;
574 * How many handles used this transaction? [t_handle_lock]
581 * struct journal_s - The journal_s type is the concrete type associated with
583 * @j_flags: General journaling state flags
584 * @j_errno: Is there an outstanding uncleared error on the journal (from a
586 * @j_sb_buffer: First part of superblock buffer
587 * @j_superblock: Second part of superblock buffer
588 * @j_format_version: Version of the superblock format
589 * @j_state_lock: Protect the various scalars in the journal
590 * @j_barrier_count: Number of processes waiting to create a barrier lock
591 * @j_barrier: The barrier lock itself
592 * @j_running_transaction: The current running transaction..
593 * @j_committing_transaction: the transaction we are pushing to disk
594 * @j_checkpoint_transactions: a linked circular list of all transactions
595 * waiting for checkpointing
596 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
597 * to start committing, or for a barrier lock to be released
598 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
599 * @j_wait_done_commit: Wait queue for waiting for commit to complete
600 * @j_wait_checkpoint: Wait queue to trigger checkpointing
601 * @j_wait_commit: Wait queue to trigger commit
602 * @j_wait_updates: Wait queue to wait for updates to complete
603 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
604 * @j_head: Journal head - identifies the first unused block in the journal
605 * @j_tail: Journal tail - identifies the oldest still-used block in the
607 * @j_free: Journal free - how many free blocks are there in the journal?
608 * @j_first: The block number of the first usable block
609 * @j_last: The block number one beyond the last usable block
610 * @j_dev: Device where we store the journal
611 * @j_blocksize: blocksize for the location where we store the journal.
612 * @j_blk_offset: starting block offset for into the device where we store the
614 * @j_fs_dev: Device which holds the client fs. For internal journal this will
616 * @j_maxlen: Total maximum capacity of the journal region on disk.
617 * @j_list_lock: Protects the buffer lists and internal buffer state.
618 * @j_inode: Optional inode where we store the journal. If present, all journal
619 * block numbers are mapped into this inode via bmap().
620 * @j_tail_sequence: Sequence number of the oldest transaction in the log
621 * @j_transaction_sequence: Sequence number of the next transaction to grant
622 * @j_commit_sequence: Sequence number of the most recently committed
624 * @j_commit_request: Sequence number of the most recent transaction wanting
626 * @j_uuid: Uuid of client object.
627 * @j_task: Pointer to the current commit thread for this journal
628 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
629 * single compound commit transaction
630 * @j_commit_interval: What is the maximum transaction lifetime before we begin
632 * @j_commit_timer: The timer used to wakeup the commit thread
633 * @j_revoke_lock: Protect the revoke table
634 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
635 * current transaction.
636 * @j_revoke_table: alternate revoke tables for j_revoke
637 * @j_wbuf: array of buffer_heads for journal_commit_transaction
638 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
639 * number that will fit in j_blocksize
640 * @j_last_sync_writer: most recent pid which did a synchronous write
641 * @j_private: An opaque pointer to fs-private information.
646 /* General journaling state flags [j_state_lock] */
647 unsigned long j_flags;
650 * Is there an outstanding uncleared error on the journal (from a prior
651 * abort)? [j_state_lock]
655 /* The superblock buffer */
656 struct buffer_head *j_sb_buffer;
657 journal_superblock_t *j_superblock;
659 /* Version of the superblock format */
660 int j_format_version;
663 * Protect the various scalars in the journal
665 spinlock_t j_state_lock;
668 * Number of processes waiting to create a barrier lock [j_state_lock]
672 /* The barrier lock itself */
673 struct mutex j_barrier;
676 * Transactions: The current running transaction...
677 * [j_state_lock] [caller holding open handle]
679 transaction_t *j_running_transaction;
682 * the transaction we are pushing to disk
683 * [j_state_lock] [caller holding open handle]
685 transaction_t *j_committing_transaction;
688 * ... and a linked circular list of all transactions waiting for
689 * checkpointing. [j_list_lock]
691 transaction_t *j_checkpoint_transactions;
694 * Wait queue for waiting for a locked transaction to start committing,
695 * or for a barrier lock to be released
697 wait_queue_head_t j_wait_transaction_locked;
699 /* Wait queue for waiting for checkpointing to complete */
700 wait_queue_head_t j_wait_logspace;
702 /* Wait queue for waiting for commit to complete */
703 wait_queue_head_t j_wait_done_commit;
705 /* Wait queue to trigger checkpointing */
706 wait_queue_head_t j_wait_checkpoint;
708 /* Wait queue to trigger commit */
709 wait_queue_head_t j_wait_commit;
711 /* Wait queue to wait for updates to complete */
712 wait_queue_head_t j_wait_updates;
714 /* Semaphore for locking against concurrent checkpoints */
715 struct mutex j_checkpoint_mutex;
718 * Journal head: identifies the first unused block in the journal.
721 unsigned long j_head;
724 * Journal tail: identifies the oldest still-used block in the journal.
727 unsigned long j_tail;
730 * Journal free: how many free blocks are there in the journal?
733 unsigned long j_free;
736 * Journal start and end: the block numbers of the first usable block
737 * and one beyond the last usable block in the journal. [j_state_lock]
739 unsigned long j_first;
740 unsigned long j_last;
743 * Device, blocksize and starting block offset for the location where we
746 struct block_device *j_dev;
748 unsigned long j_blk_offset;
751 * Device which holds the client fs. For internal journal this will be
754 struct block_device *j_fs_dev;
756 /* Total maximum capacity of the journal region on disk. */
757 unsigned int j_maxlen;
760 * Protects the buffer lists and internal buffer state.
762 spinlock_t j_list_lock;
764 /* Optional inode where we store the journal. If present, all */
765 /* journal block numbers are mapped into this inode via */
767 struct inode *j_inode;
770 * Sequence number of the oldest transaction in the log [j_state_lock]
772 tid_t j_tail_sequence;
775 * Sequence number of the next transaction to grant [j_state_lock]
777 tid_t j_transaction_sequence;
780 * Sequence number of the most recently committed transaction
783 tid_t j_commit_sequence;
786 * Sequence number of the most recent transaction wanting commit
789 tid_t j_commit_request;
792 * Journal uuid: identifies the object (filesystem, LVM volume etc)
793 * backed by this journal. This will eventually be replaced by an array
794 * of uuids, allowing us to index multiple devices within a single
795 * journal and to perform atomic updates across them.
799 /* Pointer to the current commit thread for this journal */
800 struct task_struct *j_task;
803 * Maximum number of metadata buffers to allow in a single compound
806 int j_max_transaction_buffers;
809 * What is the maximum transaction lifetime before we begin a commit?
811 unsigned long j_commit_interval;
813 /* The timer used to wakeup the commit thread: */
814 struct timer_list j_commit_timer;
817 * The revoke table: maintains the list of revoked blocks in the
818 * current transaction. [j_revoke_lock]
820 spinlock_t j_revoke_lock;
821 struct jbd_revoke_table_s *j_revoke;
822 struct jbd_revoke_table_s *j_revoke_table[2];
825 * array of bhs for journal_commit_transaction
827 struct buffer_head **j_wbuf;
830 pid_t j_last_sync_writer;
833 * An opaque pointer to fs-private information. ext3 puts its
834 * superblock pointer here
840 * Journal flag definitions
842 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
843 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
844 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
845 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
846 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
847 #define JFS_BARRIER 0x020 /* Use IDE barriers */
850 * Function declarations for the journaling transaction and buffer
855 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
856 extern void __journal_unfile_buffer(struct journal_head *);
857 extern void __journal_refile_buffer(struct journal_head *);
858 extern void journal_refile_buffer(journal_t *, struct journal_head *);
859 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
860 extern void __journal_free_buffer(struct journal_head *bh);
861 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
862 extern void __journal_clean_data_list(transaction_t *transaction);
864 /* Log buffer allocation */
865 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
866 int journal_next_log_block(journal_t *, unsigned long *);
868 /* Commit management */
869 extern void journal_commit_transaction(journal_t *);
871 /* Checkpoint list management */
872 int __journal_clean_checkpoint_list(journal_t *journal);
873 int __journal_remove_checkpoint(struct journal_head *);
874 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
878 journal_write_metadata_buffer(transaction_t *transaction,
879 struct journal_head *jh_in,
880 struct journal_head **jh_out,
881 unsigned long blocknr);
883 /* Transaction locking */
884 extern void __wait_on_journal (journal_t *);
889 * We need to lock the journal during transaction state changes so that nobody
890 * ever tries to take a handle on the running transaction while we are in the
891 * middle of moving it to the commit phase. j_state_lock does this.
893 * Note that the locking is completely interrupt unsafe. We never touch
894 * journal structures from interrupts.
897 static inline handle_t *journal_current_handle(void)
899 return current->journal_info;
902 /* The journaling code user interface:
904 * Create and destroy handles
905 * Register buffer modifications against the current transaction.
908 extern handle_t *journal_start(journal_t *, int nblocks);
909 extern int journal_restart (handle_t *, int nblocks);
910 extern int journal_extend (handle_t *, int nblocks);
911 extern int journal_get_write_access(handle_t *, struct buffer_head *);
912 extern int journal_get_create_access (handle_t *, struct buffer_head *);
913 extern int journal_get_undo_access(handle_t *, struct buffer_head *);
914 extern int journal_dirty_data (handle_t *, struct buffer_head *);
915 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
916 extern void journal_release_buffer (handle_t *, struct buffer_head *);
917 extern int journal_forget (handle_t *, struct buffer_head *);
918 extern void journal_sync_buffer (struct buffer_head *);
919 extern void journal_invalidatepage(journal_t *,
920 struct page *, unsigned long);
921 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
922 extern int journal_stop(handle_t *);
923 extern int journal_flush (journal_t *);
924 extern void journal_lock_updates (journal_t *);
925 extern void journal_unlock_updates (journal_t *);
927 extern journal_t * journal_init_dev(struct block_device *bdev,
928 struct block_device *fs_dev,
929 int start, int len, int bsize);
930 extern journal_t * journal_init_inode (struct inode *);
931 extern int journal_update_format (journal_t *);
932 extern int journal_check_used_features
933 (journal_t *, unsigned long, unsigned long, unsigned long);
934 extern int journal_check_available_features
935 (journal_t *, unsigned long, unsigned long, unsigned long);
936 extern int journal_set_features
937 (journal_t *, unsigned long, unsigned long, unsigned long);
938 extern int journal_create (journal_t *);
939 extern int journal_load (journal_t *journal);
940 extern void journal_destroy (journal_t *);
941 extern int journal_recover (journal_t *journal);
942 extern int journal_wipe (journal_t *, int);
943 extern int journal_skip_recovery (journal_t *);
944 extern void journal_update_superblock (journal_t *, int);
945 extern void __journal_abort_hard (journal_t *);
946 extern void journal_abort (journal_t *, int);
947 extern int journal_errno (journal_t *);
948 extern void journal_ack_err (journal_t *);
949 extern int journal_clear_err (journal_t *);
950 extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
951 extern int journal_force_commit(journal_t *);
954 * journal_head management
956 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
957 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
958 void journal_remove_journal_head(struct buffer_head *bh);
959 void journal_put_journal_head(struct journal_head *jh);
964 extern struct kmem_cache *jbd_handle_cache;
966 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
968 return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
971 static inline void jbd_free_handle(handle_t *handle)
973 kmem_cache_free(jbd_handle_cache, handle);
976 /* Primary revoke support */
977 #define JOURNAL_REVOKE_DEFAULT_HASH 256
978 extern int journal_init_revoke(journal_t *, int);
979 extern void journal_destroy_revoke_caches(void);
980 extern int journal_init_revoke_caches(void);
982 extern void journal_destroy_revoke(journal_t *);
983 extern int journal_revoke (handle_t *,
984 unsigned long, struct buffer_head *);
985 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
986 extern void journal_write_revoke_records(journal_t *, transaction_t *);
988 /* Recovery revoke support */
989 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
990 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
991 extern void journal_clear_revoke(journal_t *);
992 extern void journal_switch_revoke_table(journal_t *journal);
995 * The log thread user interface:
997 * Request space in the current transaction, and force transaction commit
998 * transitions on demand.
1001 int __log_space_left(journal_t *); /* Called with journal locked */
1002 int log_start_commit(journal_t *journal, tid_t tid);
1003 int __log_start_commit(journal_t *journal, tid_t tid);
1004 int journal_start_commit(journal_t *journal, tid_t *tid);
1005 int journal_force_commit_nested(journal_t *journal);
1006 int log_wait_commit(journal_t *journal, tid_t tid);
1007 int log_do_checkpoint(journal_t *journal);
1009 void __log_wait_for_space(journal_t *journal);
1010 extern void __journal_drop_transaction(journal_t *, transaction_t *);
1011 extern int cleanup_journal_tail(journal_t *);
1013 /* Debugging code only: */
1015 #define jbd_ENOSYS() \
1017 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1018 current->state = TASK_UNINTERRUPTIBLE; \
1025 * Simple test wrapper function to test the JFS_ABORT state flag. This
1026 * bit, when set, indicates that we have had a fatal error somewhere,
1027 * either inside the journaling layer or indicated to us by the client
1028 * (eg. ext3), and that we and should not commit any further
1032 static inline int is_journal_aborted(journal_t *journal)
1034 return journal->j_flags & JFS_ABORT;
1037 static inline int is_handle_aborted(handle_t *handle)
1039 if (handle->h_aborted)
1041 return is_journal_aborted(handle->h_transaction->t_journal);
1044 static inline void journal_abort_handle(handle_t *handle)
1046 handle->h_aborted = 1;
1049 #endif /* __KERNEL__ */
1051 /* Comparison functions for transaction IDs: perform comparisons using
1052 * modulo arithmetic so that they work over sequence number wraps. */
1054 static inline int tid_gt(tid_t x, tid_t y)
1056 int difference = (x - y);
1057 return (difference > 0);
1060 static inline int tid_geq(tid_t x, tid_t y)
1062 int difference = (x - y);
1063 return (difference >= 0);
1066 extern int journal_blocks_per_page(struct inode *inode);
1069 * Return the minimum number of blocks which must be free in the journal
1070 * before a new transaction may be started. Must be called under j_state_lock.
1072 static inline int jbd_space_needed(journal_t *journal)
1074 int nblocks = journal->j_max_transaction_buffers;
1075 if (journal->j_committing_transaction)
1076 nblocks += journal->j_committing_transaction->
1077 t_outstanding_credits;
1082 * Definitions which augment the buffer_head layer
1085 /* journaling buffer types */
1086 #define BJ_None 0 /* Not journaled */
1087 #define BJ_SyncData 1 /* Normal data: flush before commit */
1088 #define BJ_Metadata 2 /* Normal journaled metadata */
1089 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1090 #define BJ_IO 4 /* Buffer is for temporary IO use */
1091 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1092 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1093 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1094 #define BJ_Locked 8 /* Locked for I/O during commit */
1097 extern int jbd_blocks_per_page(struct inode *inode);
1101 #define buffer_trace_init(bh) do {} while (0)
1102 #define print_buffer_fields(bh) do {} while (0)
1103 #define print_buffer_trace(bh) do {} while (0)
1104 #define BUFFER_TRACE(bh, info) do {} while (0)
1105 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1106 #define JBUFFER_TRACE(jh, info) do {} while (0)
1108 #endif /* __KERNEL__ */
1110 #endif /* _LINUX_JBD_H */