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 static inline void *jbd_alloc(size_t size, gfp_t flags)
77 return (void *)__get_free_pages(flags, get_order(size));
80 static inline void jbd_free(void *ptr, size_t size)
82 free_pages((unsigned long)ptr, get_order(size));
85 #define JFS_MIN_JOURNAL_BLOCKS 1024
90 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
92 * All filesystem modifications made by the process go
93 * through this handle. Recursive operations (such as quota operations)
94 * are gathered into a single update.
96 * The buffer credits field is used to account for journaled buffers
97 * being modified by the running process. To ensure that there is
98 * enough log space for all outstanding operations, we need to limit the
99 * number of outstanding buffers possible at any time. When the
100 * operation completes, any buffer credits not used are credited back to
101 * the transaction, so that at all times we know how many buffers the
102 * outstanding updates on a transaction might possibly touch.
104 * This is an opaque datatype.
106 typedef struct handle_s handle_t; /* Atomic operation type */
110 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
112 * journal_t is linked to from the fs superblock structure.
114 * We use the journal_t to keep track of all outstanding transaction
115 * activity on the filesystem, and to manage the state of the log
118 * This is an opaque datatype.
120 typedef struct journal_s journal_t; /* Journal control structure */
124 * Internal structures used by the logging mechanism:
127 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
134 * Descriptor block types:
137 #define JFS_DESCRIPTOR_BLOCK 1
138 #define JFS_COMMIT_BLOCK 2
139 #define JFS_SUPERBLOCK_V1 3
140 #define JFS_SUPERBLOCK_V2 4
141 #define JFS_REVOKE_BLOCK 5
144 * Standard header for all descriptor blocks:
146 typedef struct journal_header_s
155 * The block tag: used to describe a single buffer in the journal
157 typedef struct journal_block_tag_s
159 __be32 t_blocknr; /* The on-disk block number */
160 __be32 t_flags; /* See below */
161 } journal_block_tag_t;
164 * The revoke descriptor: used on disk to describe a series of blocks to
165 * be revoked from the log
167 typedef struct journal_revoke_header_s
169 journal_header_t r_header;
170 __be32 r_count; /* Count of bytes used in the block */
171 } journal_revoke_header_t;
174 /* Definitions for the journal tag flags word: */
175 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
176 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
177 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
178 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
182 * The journal superblock. All fields are in big-endian byte order.
184 typedef struct journal_superblock_s
187 journal_header_t s_header;
190 /* Static information describing the journal */
191 __be32 s_blocksize; /* journal device blocksize */
192 __be32 s_maxlen; /* total blocks in journal file */
193 __be32 s_first; /* first block of log information */
196 /* Dynamic information describing the current state of the log */
197 __be32 s_sequence; /* first commit ID expected in log */
198 __be32 s_start; /* blocknr of start of log */
201 /* Error value, as set by journal_abort(). */
205 /* Remaining fields are only valid in a version-2 superblock */
206 __be32 s_feature_compat; /* compatible feature set */
207 __be32 s_feature_incompat; /* incompatible feature set */
208 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
210 __u8 s_uuid[16]; /* 128-bit uuid for journal */
213 __be32 s_nr_users; /* Nr of filesystems sharing log */
215 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
218 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
219 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
225 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
227 } journal_superblock_t;
229 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
230 ((j)->j_format_version >= 2 && \
231 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
232 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
233 ((j)->j_format_version >= 2 && \
234 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
235 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
236 ((j)->j_format_version >= 2 && \
237 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
239 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
241 /* Features known to this kernel version: */
242 #define JFS_KNOWN_COMPAT_FEATURES 0
243 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
244 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
248 #include <linux/fs.h>
249 #include <linux/sched.h>
251 #define JBD_ASSERTIONS
252 #ifdef JBD_ASSERTIONS
253 #define J_ASSERT(assert) \
257 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
258 __FUNCTION__, __FILE__, __LINE__, # assert); \
263 #if defined(CONFIG_BUFFER_DEBUG)
264 void buffer_assertion_failure(struct buffer_head *bh);
265 #define J_ASSERT_BH(bh, expr) \
268 buffer_assertion_failure(bh); \
271 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
273 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
274 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
278 #define J_ASSERT(assert) do { } while (0)
279 #endif /* JBD_ASSERTIONS */
281 #if defined(JBD_PARANOID_IOFAIL)
282 #define J_EXPECT(expr, why...) J_ASSERT(expr)
283 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
284 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
286 #define __journal_expect(expr, why...) \
291 "EXT3-fs unexpected failure: %s;\n",# expr); \
292 printk(KERN_ERR why "\n"); \
296 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
297 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
298 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
301 enum jbd_state_bits {
302 BH_JBD /* Has an attached ext3 journal_head */
304 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
305 BH_Freed, /* Has been freed (truncated) */
306 BH_Revoked, /* Has been revoked from the log */
307 BH_RevokeValid, /* Revoked flag is valid */
308 BH_JBDDirty, /* Is dirty but journaled */
309 BH_State, /* Pins most journal_head state */
310 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
311 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
315 BUFFER_FNS(JWrite, jwrite)
316 BUFFER_FNS(JBDDirty, jbddirty)
317 TAS_BUFFER_FNS(JBDDirty, jbddirty)
318 BUFFER_FNS(Revoked, revoked)
319 TAS_BUFFER_FNS(Revoked, revoked)
320 BUFFER_FNS(RevokeValid, revokevalid)
321 TAS_BUFFER_FNS(RevokeValid, revokevalid)
322 BUFFER_FNS(Freed, freed)
324 static inline struct buffer_head *jh2bh(struct journal_head *jh)
329 static inline struct journal_head *bh2jh(struct buffer_head *bh)
331 return bh->b_private;
334 static inline void jbd_lock_bh_state(struct buffer_head *bh)
336 bit_spin_lock(BH_State, &bh->b_state);
339 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
341 return bit_spin_trylock(BH_State, &bh->b_state);
344 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
346 return bit_spin_is_locked(BH_State, &bh->b_state);
349 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
351 bit_spin_unlock(BH_State, &bh->b_state);
354 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
356 bit_spin_lock(BH_JournalHead, &bh->b_state);
359 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
361 bit_spin_unlock(BH_JournalHead, &bh->b_state);
364 struct jbd_revoke_table_s;
367 * struct handle_s - The handle_s type is the concrete type associated with
369 * @h_transaction: Which compound transaction is this update a part of?
370 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
371 * @h_ref: Reference count on this handle
372 * @h_err: Field for caller's use to track errors through large fs operations
373 * @h_sync: flag for sync-on-close
374 * @h_jdata: flag to force data journaling
375 * @h_aborted: flag indicating fatal error on handle
376 * @h_lockdep_map: lockdep info for debugging lock problems
379 /* Docbook can't yet cope with the bit fields, but will leave the documentation
380 * in so it can be fixed later.
385 /* Which compound transaction is this update a part of? */
386 transaction_t *h_transaction;
388 /* Number of remaining buffers we are allowed to dirty: */
389 int h_buffer_credits;
391 /* Reference count on this handle */
394 /* Field for caller's use to track errors through large fs */
398 /* Flags [no locking] */
399 unsigned int h_sync: 1; /* sync-on-close */
400 unsigned int h_jdata: 1; /* force data journaling */
401 unsigned int h_aborted: 1; /* fatal error on handle */
403 #ifdef CONFIG_DEBUG_LOCK_ALLOC
404 struct lockdep_map h_lockdep_map;
409 /* The transaction_t type is the guts of the journaling mechanism. It
410 * tracks a compound transaction through its various states:
412 * RUNNING: accepting new updates
413 * LOCKED: Updates still running but we don't accept new ones
414 * RUNDOWN: Updates are tidying up but have finished requesting
415 * new buffers to modify (state not used for now)
416 * FLUSH: All updates complete, but we are still writing to disk
417 * COMMIT: All data on disk, writing commit record
418 * FINISHED: We still have to keep the transaction for checkpointing.
420 * The transaction keeps track of all of the buffers modified by a
421 * running transaction, and all of the buffers committed but not yet
422 * flushed to home for finished transactions.
429 * ->jbd_lock_bh_journal_head() (This is "innermost")
432 * ->jbd_lock_bh_state()
434 * jbd_lock_bh_state()
441 * ->j_list_lock (journal_unmap_buffer)
447 /* Pointer to the journal for this transaction. [no locking] */
448 journal_t *t_journal;
450 /* Sequence number for this transaction [no locking] */
454 * Transaction's current state
455 * [no locking - only kjournald alters this]
456 * FIXME: needs barriers
457 * KLUDGE: [use j_state_lock]
469 * Where in the log does this transaction's commit start? [no locking]
471 unsigned long t_log_start;
473 /* Number of buffers on the t_buffers list [j_list_lock] */
477 * Doubly-linked circular list of all buffers reserved but not yet
478 * modified by this transaction [j_list_lock]
480 struct journal_head *t_reserved_list;
483 * Doubly-linked circular list of all buffers under writeout during
484 * commit [j_list_lock]
486 struct journal_head *t_locked_list;
489 * Doubly-linked circular list of all metadata buffers owned by this
490 * transaction [j_list_lock]
492 struct journal_head *t_buffers;
495 * Doubly-linked circular list of all data buffers still to be
496 * flushed before this transaction can be committed [j_list_lock]
498 struct journal_head *t_sync_datalist;
501 * Doubly-linked circular list of all forget buffers (superseded
502 * buffers which we can un-checkpoint once this transaction commits)
505 struct journal_head *t_forget;
508 * Doubly-linked circular list of all buffers still to be flushed before
509 * this transaction can be checkpointed. [j_list_lock]
511 struct journal_head *t_checkpoint_list;
514 * Doubly-linked circular list of all buffers submitted for IO while
515 * checkpointing. [j_list_lock]
517 struct journal_head *t_checkpoint_io_list;
520 * Doubly-linked circular list of temporary buffers currently undergoing
521 * IO in the log [j_list_lock]
523 struct journal_head *t_iobuf_list;
526 * Doubly-linked circular list of metadata buffers being shadowed by log
527 * IO. The IO buffers on the iobuf list and the shadow buffers on this
528 * list match each other one for one at all times. [j_list_lock]
530 struct journal_head *t_shadow_list;
533 * Doubly-linked circular list of control buffers being written to the
536 struct journal_head *t_log_list;
539 * Protects info related to handles
541 spinlock_t t_handle_lock;
544 * Number of outstanding updates running on this transaction
550 * Number of buffers reserved for use by all handles in this transaction
551 * handle but not yet modified. [t_handle_lock]
553 int t_outstanding_credits;
556 * Forward and backward links for the circular list of all transactions
557 * awaiting checkpoint. [j_list_lock]
559 transaction_t *t_cpnext, *t_cpprev;
562 * When will the transaction expire (become due for commit), in jiffies?
565 unsigned long t_expires;
568 * How many handles used this transaction? [t_handle_lock]
575 * struct journal_s - The journal_s type is the concrete type associated with
577 * @j_flags: General journaling state flags
578 * @j_errno: Is there an outstanding uncleared error on the journal (from a
580 * @j_sb_buffer: First part of superblock buffer
581 * @j_superblock: Second part of superblock buffer
582 * @j_format_version: Version of the superblock format
583 * @j_state_lock: Protect the various scalars in the journal
584 * @j_barrier_count: Number of processes waiting to create a barrier lock
585 * @j_barrier: The barrier lock itself
586 * @j_running_transaction: The current running transaction..
587 * @j_committing_transaction: the transaction we are pushing to disk
588 * @j_checkpoint_transactions: a linked circular list of all transactions
589 * waiting for checkpointing
590 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
591 * to start committing, or for a barrier lock to be released
592 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
593 * @j_wait_done_commit: Wait queue for waiting for commit to complete
594 * @j_wait_checkpoint: Wait queue to trigger checkpointing
595 * @j_wait_commit: Wait queue to trigger commit
596 * @j_wait_updates: Wait queue to wait for updates to complete
597 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
598 * @j_head: Journal head - identifies the first unused block in the journal
599 * @j_tail: Journal tail - identifies the oldest still-used block in the
601 * @j_free: Journal free - how many free blocks are there in the journal?
602 * @j_first: The block number of the first usable block
603 * @j_last: The block number one beyond the last usable block
604 * @j_dev: Device where we store the journal
605 * @j_blocksize: blocksize for the location where we store the journal.
606 * @j_blk_offset: starting block offset for into the device where we store the
608 * @j_fs_dev: Device which holds the client fs. For internal journal this will
610 * @j_maxlen: Total maximum capacity of the journal region on disk.
611 * @j_list_lock: Protects the buffer lists and internal buffer state.
612 * @j_inode: Optional inode where we store the journal. If present, all journal
613 * block numbers are mapped into this inode via bmap().
614 * @j_tail_sequence: Sequence number of the oldest transaction in the log
615 * @j_transaction_sequence: Sequence number of the next transaction to grant
616 * @j_commit_sequence: Sequence number of the most recently committed
618 * @j_commit_request: Sequence number of the most recent transaction wanting
620 * @j_uuid: Uuid of client object.
621 * @j_task: Pointer to the current commit thread for this journal
622 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
623 * single compound commit transaction
624 * @j_commit_interval: What is the maximum transaction lifetime before we begin
626 * @j_commit_timer: The timer used to wakeup the commit thread
627 * @j_revoke_lock: Protect the revoke table
628 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
629 * current transaction.
630 * @j_revoke_table: alternate revoke tables for j_revoke
631 * @j_wbuf: array of buffer_heads for journal_commit_transaction
632 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
633 * number that will fit in j_blocksize
634 * @j_last_sync_writer: most recent pid which did a synchronous write
635 * @j_private: An opaque pointer to fs-private information.
640 /* General journaling state flags [j_state_lock] */
641 unsigned long j_flags;
644 * Is there an outstanding uncleared error on the journal (from a prior
645 * abort)? [j_state_lock]
649 /* The superblock buffer */
650 struct buffer_head *j_sb_buffer;
651 journal_superblock_t *j_superblock;
653 /* Version of the superblock format */
654 int j_format_version;
657 * Protect the various scalars in the journal
659 spinlock_t j_state_lock;
662 * Number of processes waiting to create a barrier lock [j_state_lock]
666 /* The barrier lock itself */
667 struct mutex j_barrier;
670 * Transactions: The current running transaction...
671 * [j_state_lock] [caller holding open handle]
673 transaction_t *j_running_transaction;
676 * the transaction we are pushing to disk
677 * [j_state_lock] [caller holding open handle]
679 transaction_t *j_committing_transaction;
682 * ... and a linked circular list of all transactions waiting for
683 * checkpointing. [j_list_lock]
685 transaction_t *j_checkpoint_transactions;
688 * Wait queue for waiting for a locked transaction to start committing,
689 * or for a barrier lock to be released
691 wait_queue_head_t j_wait_transaction_locked;
693 /* Wait queue for waiting for checkpointing to complete */
694 wait_queue_head_t j_wait_logspace;
696 /* Wait queue for waiting for commit to complete */
697 wait_queue_head_t j_wait_done_commit;
699 /* Wait queue to trigger checkpointing */
700 wait_queue_head_t j_wait_checkpoint;
702 /* Wait queue to trigger commit */
703 wait_queue_head_t j_wait_commit;
705 /* Wait queue to wait for updates to complete */
706 wait_queue_head_t j_wait_updates;
708 /* Semaphore for locking against concurrent checkpoints */
709 struct mutex j_checkpoint_mutex;
712 * Journal head: identifies the first unused block in the journal.
715 unsigned long j_head;
718 * Journal tail: identifies the oldest still-used block in the journal.
721 unsigned long j_tail;
724 * Journal free: how many free blocks are there in the journal?
727 unsigned long j_free;
730 * Journal start and end: the block numbers of the first usable block
731 * and one beyond the last usable block in the journal. [j_state_lock]
733 unsigned long j_first;
734 unsigned long j_last;
737 * Device, blocksize and starting block offset for the location where we
740 struct block_device *j_dev;
742 unsigned long j_blk_offset;
745 * Device which holds the client fs. For internal journal this will be
748 struct block_device *j_fs_dev;
750 /* Total maximum capacity of the journal region on disk. */
751 unsigned int j_maxlen;
754 * Protects the buffer lists and internal buffer state.
756 spinlock_t j_list_lock;
758 /* Optional inode where we store the journal. If present, all */
759 /* journal block numbers are mapped into this inode via */
761 struct inode *j_inode;
764 * Sequence number of the oldest transaction in the log [j_state_lock]
766 tid_t j_tail_sequence;
769 * Sequence number of the next transaction to grant [j_state_lock]
771 tid_t j_transaction_sequence;
774 * Sequence number of the most recently committed transaction
777 tid_t j_commit_sequence;
780 * Sequence number of the most recent transaction wanting commit
783 tid_t j_commit_request;
786 * Journal uuid: identifies the object (filesystem, LVM volume etc)
787 * backed by this journal. This will eventually be replaced by an array
788 * of uuids, allowing us to index multiple devices within a single
789 * journal and to perform atomic updates across them.
793 /* Pointer to the current commit thread for this journal */
794 struct task_struct *j_task;
797 * Maximum number of metadata buffers to allow in a single compound
800 int j_max_transaction_buffers;
803 * What is the maximum transaction lifetime before we begin a commit?
805 unsigned long j_commit_interval;
807 /* The timer used to wakeup the commit thread: */
808 struct timer_list j_commit_timer;
811 * The revoke table: maintains the list of revoked blocks in the
812 * current transaction. [j_revoke_lock]
814 spinlock_t j_revoke_lock;
815 struct jbd_revoke_table_s *j_revoke;
816 struct jbd_revoke_table_s *j_revoke_table[2];
819 * array of bhs for journal_commit_transaction
821 struct buffer_head **j_wbuf;
824 pid_t j_last_sync_writer;
827 * An opaque pointer to fs-private information. ext3 puts its
828 * superblock pointer here
834 * Journal flag definitions
836 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
837 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
838 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
839 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
840 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
841 #define JFS_BARRIER 0x020 /* Use IDE barriers */
844 * Function declarations for the journaling transaction and buffer
849 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
850 extern void __journal_unfile_buffer(struct journal_head *);
851 extern void __journal_refile_buffer(struct journal_head *);
852 extern void journal_refile_buffer(journal_t *, struct journal_head *);
853 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
854 extern void __journal_free_buffer(struct journal_head *bh);
855 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
856 extern void __journal_clean_data_list(transaction_t *transaction);
858 /* Log buffer allocation */
859 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
860 int journal_next_log_block(journal_t *, unsigned long *);
862 /* Commit management */
863 extern void journal_commit_transaction(journal_t *);
865 /* Checkpoint list management */
866 int __journal_clean_checkpoint_list(journal_t *journal);
867 int __journal_remove_checkpoint(struct journal_head *);
868 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
872 journal_write_metadata_buffer(transaction_t *transaction,
873 struct journal_head *jh_in,
874 struct journal_head **jh_out,
875 unsigned long blocknr);
877 /* Transaction locking */
878 extern void __wait_on_journal (journal_t *);
883 * We need to lock the journal during transaction state changes so that nobody
884 * ever tries to take a handle on the running transaction while we are in the
885 * middle of moving it to the commit phase. j_state_lock does this.
887 * Note that the locking is completely interrupt unsafe. We never touch
888 * journal structures from interrupts.
891 static inline handle_t *journal_current_handle(void)
893 return current->journal_info;
896 /* The journaling code user interface:
898 * Create and destroy handles
899 * Register buffer modifications against the current transaction.
902 extern handle_t *journal_start(journal_t *, int nblocks);
903 extern int journal_restart (handle_t *, int nblocks);
904 extern int journal_extend (handle_t *, int nblocks);
905 extern int journal_get_write_access(handle_t *, struct buffer_head *);
906 extern int journal_get_create_access (handle_t *, struct buffer_head *);
907 extern int journal_get_undo_access(handle_t *, struct buffer_head *);
908 extern int journal_dirty_data (handle_t *, struct buffer_head *);
909 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
910 extern void journal_release_buffer (handle_t *, struct buffer_head *);
911 extern int journal_forget (handle_t *, struct buffer_head *);
912 extern void journal_sync_buffer (struct buffer_head *);
913 extern void journal_invalidatepage(journal_t *,
914 struct page *, unsigned long);
915 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
916 extern int journal_stop(handle_t *);
917 extern int journal_flush (journal_t *);
918 extern void journal_lock_updates (journal_t *);
919 extern void journal_unlock_updates (journal_t *);
921 extern journal_t * journal_init_dev(struct block_device *bdev,
922 struct block_device *fs_dev,
923 int start, int len, int bsize);
924 extern journal_t * journal_init_inode (struct inode *);
925 extern int journal_update_format (journal_t *);
926 extern int journal_check_used_features
927 (journal_t *, unsigned long, unsigned long, unsigned long);
928 extern int journal_check_available_features
929 (journal_t *, unsigned long, unsigned long, unsigned long);
930 extern int journal_set_features
931 (journal_t *, unsigned long, unsigned long, unsigned long);
932 extern int journal_create (journal_t *);
933 extern int journal_load (journal_t *journal);
934 extern void journal_destroy (journal_t *);
935 extern int journal_recover (journal_t *journal);
936 extern int journal_wipe (journal_t *, int);
937 extern int journal_skip_recovery (journal_t *);
938 extern void journal_update_superblock (journal_t *, int);
939 extern void __journal_abort_hard (journal_t *);
940 extern void journal_abort (journal_t *, int);
941 extern int journal_errno (journal_t *);
942 extern void journal_ack_err (journal_t *);
943 extern int journal_clear_err (journal_t *);
944 extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
945 extern int journal_force_commit(journal_t *);
948 * journal_head management
950 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
951 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
952 void journal_remove_journal_head(struct buffer_head *bh);
953 void journal_put_journal_head(struct journal_head *jh);
958 extern struct kmem_cache *jbd_handle_cache;
960 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
962 return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
965 static inline void jbd_free_handle(handle_t *handle)
967 kmem_cache_free(jbd_handle_cache, handle);
970 /* Primary revoke support */
971 #define JOURNAL_REVOKE_DEFAULT_HASH 256
972 extern int journal_init_revoke(journal_t *, int);
973 extern void journal_destroy_revoke_caches(void);
974 extern int journal_init_revoke_caches(void);
976 extern void journal_destroy_revoke(journal_t *);
977 extern int journal_revoke (handle_t *,
978 unsigned long, struct buffer_head *);
979 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
980 extern void journal_write_revoke_records(journal_t *, transaction_t *);
982 /* Recovery revoke support */
983 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
984 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
985 extern void journal_clear_revoke(journal_t *);
986 extern void journal_switch_revoke_table(journal_t *journal);
989 * The log thread user interface:
991 * Request space in the current transaction, and force transaction commit
992 * transitions on demand.
995 int __log_space_left(journal_t *); /* Called with journal locked */
996 int log_start_commit(journal_t *journal, tid_t tid);
997 int __log_start_commit(journal_t *journal, tid_t tid);
998 int journal_start_commit(journal_t *journal, tid_t *tid);
999 int journal_force_commit_nested(journal_t *journal);
1000 int log_wait_commit(journal_t *journal, tid_t tid);
1001 int log_do_checkpoint(journal_t *journal);
1003 void __log_wait_for_space(journal_t *journal);
1004 extern void __journal_drop_transaction(journal_t *, transaction_t *);
1005 extern int cleanup_journal_tail(journal_t *);
1007 /* Debugging code only: */
1009 #define jbd_ENOSYS() \
1011 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1012 current->state = TASK_UNINTERRUPTIBLE; \
1019 * Simple test wrapper function to test the JFS_ABORT state flag. This
1020 * bit, when set, indicates that we have had a fatal error somewhere,
1021 * either inside the journaling layer or indicated to us by the client
1022 * (eg. ext3), and that we and should not commit any further
1026 static inline int is_journal_aborted(journal_t *journal)
1028 return journal->j_flags & JFS_ABORT;
1031 static inline int is_handle_aborted(handle_t *handle)
1033 if (handle->h_aborted)
1035 return is_journal_aborted(handle->h_transaction->t_journal);
1038 static inline void journal_abort_handle(handle_t *handle)
1040 handle->h_aborted = 1;
1043 #endif /* __KERNEL__ */
1045 /* Comparison functions for transaction IDs: perform comparisons using
1046 * modulo arithmetic so that they work over sequence number wraps. */
1048 static inline int tid_gt(tid_t x, tid_t y)
1050 int difference = (x - y);
1051 return (difference > 0);
1054 static inline int tid_geq(tid_t x, tid_t y)
1056 int difference = (x - y);
1057 return (difference >= 0);
1060 extern int journal_blocks_per_page(struct inode *inode);
1063 * Return the minimum number of blocks which must be free in the journal
1064 * before a new transaction may be started. Must be called under j_state_lock.
1066 static inline int jbd_space_needed(journal_t *journal)
1068 int nblocks = journal->j_max_transaction_buffers;
1069 if (journal->j_committing_transaction)
1070 nblocks += journal->j_committing_transaction->
1071 t_outstanding_credits;
1076 * Definitions which augment the buffer_head layer
1079 /* journaling buffer types */
1080 #define BJ_None 0 /* Not journaled */
1081 #define BJ_SyncData 1 /* Normal data: flush before commit */
1082 #define BJ_Metadata 2 /* Normal journaled metadata */
1083 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1084 #define BJ_IO 4 /* Buffer is for temporary IO use */
1085 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1086 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1087 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1088 #define BJ_Locked 8 /* Locked for I/O during commit */
1091 extern int jbd_blocks_per_page(struct inode *inode);
1095 #define buffer_trace_init(bh) do {} while (0)
1096 #define print_buffer_fields(bh) do {} while (0)
1097 #define print_buffer_trace(bh) do {} while (0)
1098 #define BUFFER_TRACE(bh, info) do {} while (0)
1099 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1100 #define JBUFFER_TRACE(jh, info) do {} while (0)
1102 #endif /* __KERNEL__ */
1104 #endif /* _LINUX_JBD_H */