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 #define journal_oom_retry 1
38 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
39 * certain classes of error which can occur due to failed IOs. Under
40 * normal use we want ext3 to continue after such errors, because
41 * hardware _can_ fail, but for debugging purposes when running tests on
42 * known-good hardware we may want to trap these errors.
44 #undef JBD_PARANOID_IOFAIL
47 * The default maximum commit age, in seconds.
49 #define JBD_DEFAULT_MAX_COMMIT_AGE 5
51 #ifdef CONFIG_JBD_DEBUG
53 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
54 * consistency checks. By default we don't do this unless
55 * CONFIG_JBD_DEBUG is on.
57 #define JBD_EXPENSIVE_CHECKING
58 extern u8 journal_enable_debug;
60 #define jbd_debug(n, f, a...) \
62 if ((n) <= journal_enable_debug) { \
63 printk (KERN_DEBUG "(%s, %d): %s: ", \
64 __FILE__, __LINE__, __func__); \
69 #define jbd_debug(f, a...) /**/
72 static inline void *jbd_alloc(size_t size, gfp_t flags)
74 return (void *)__get_free_pages(flags, get_order(size));
77 static inline void jbd_free(void *ptr, size_t size)
79 free_pages((unsigned long)ptr, get_order(size));
82 #define JFS_MIN_JOURNAL_BLOCKS 1024
86 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
88 * All filesystem modifications made by the process go
89 * through this handle. Recursive operations (such as quota operations)
90 * are gathered into a single update.
92 * The buffer credits field is used to account for journaled buffers
93 * being modified by the running process. To ensure that there is
94 * enough log space for all outstanding operations, we need to limit the
95 * number of outstanding buffers possible at any time. When the
96 * operation completes, any buffer credits not used are credited back to
97 * the transaction, so that at all times we know how many buffers the
98 * outstanding updates on a transaction might possibly touch.
100 * This is an opaque datatype.
102 typedef struct handle_s handle_t; /* Atomic operation type */
106 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
108 * journal_t is linked to from the fs superblock structure.
110 * We use the journal_t to keep track of all outstanding transaction
111 * activity on the filesystem, and to manage the state of the log
114 * This is an opaque datatype.
116 typedef struct journal_s journal_t; /* Journal control structure */
120 * Internal structures used by the logging mechanism:
123 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
130 * Descriptor block types:
133 #define JFS_DESCRIPTOR_BLOCK 1
134 #define JFS_COMMIT_BLOCK 2
135 #define JFS_SUPERBLOCK_V1 3
136 #define JFS_SUPERBLOCK_V2 4
137 #define JFS_REVOKE_BLOCK 5
140 * Standard header for all descriptor blocks:
142 typedef struct journal_header_s
151 * The block tag: used to describe a single buffer in the journal
153 typedef struct journal_block_tag_s
155 __be32 t_blocknr; /* The on-disk block number */
156 __be32 t_flags; /* See below */
157 } journal_block_tag_t;
160 * The revoke descriptor: used on disk to describe a series of blocks to
161 * be revoked from the log
163 typedef struct journal_revoke_header_s
165 journal_header_t r_header;
166 __be32 r_count; /* Count of bytes used in the block */
167 } journal_revoke_header_t;
170 /* Definitions for the journal tag flags word: */
171 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
172 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
173 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
174 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
178 * The journal superblock. All fields are in big-endian byte order.
180 typedef struct journal_superblock_s
183 journal_header_t s_header;
186 /* Static information describing the journal */
187 __be32 s_blocksize; /* journal device blocksize */
188 __be32 s_maxlen; /* total blocks in journal file */
189 __be32 s_first; /* first block of log information */
192 /* Dynamic information describing the current state of the log */
193 __be32 s_sequence; /* first commit ID expected in log */
194 __be32 s_start; /* blocknr of start of log */
197 /* Error value, as set by journal_abort(). */
201 /* Remaining fields are only valid in a version-2 superblock */
202 __be32 s_feature_compat; /* compatible feature set */
203 __be32 s_feature_incompat; /* incompatible feature set */
204 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
206 __u8 s_uuid[16]; /* 128-bit uuid for journal */
209 __be32 s_nr_users; /* Nr of filesystems sharing log */
211 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
214 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
215 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
221 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
223 } journal_superblock_t;
225 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
226 ((j)->j_format_version >= 2 && \
227 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
228 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
229 ((j)->j_format_version >= 2 && \
230 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
231 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
232 ((j)->j_format_version >= 2 && \
233 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
235 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
237 /* Features known to this kernel version: */
238 #define JFS_KNOWN_COMPAT_FEATURES 0
239 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
240 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
244 #include <linux/fs.h>
245 #include <linux/sched.h>
247 #define J_ASSERT(assert) BUG_ON(!(assert))
249 #if defined(CONFIG_BUFFER_DEBUG)
250 void buffer_assertion_failure(struct buffer_head *bh);
251 #define J_ASSERT_BH(bh, expr) \
254 buffer_assertion_failure(bh); \
257 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
259 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
260 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
263 #if defined(JBD_PARANOID_IOFAIL)
264 #define J_EXPECT(expr, why...) J_ASSERT(expr)
265 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
266 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
268 #define __journal_expect(expr, why...) \
273 "EXT3-fs unexpected failure: %s;\n",# expr); \
274 printk(KERN_ERR why "\n"); \
278 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
279 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
280 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
283 enum jbd_state_bits {
284 BH_JBD /* Has an attached ext3 journal_head */
286 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
287 BH_Freed, /* Has been freed (truncated) */
288 BH_Revoked, /* Has been revoked from the log */
289 BH_RevokeValid, /* Revoked flag is valid */
290 BH_JBDDirty, /* Is dirty but journaled */
291 BH_State, /* Pins most journal_head state */
292 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
293 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
297 BUFFER_FNS(JWrite, jwrite)
298 BUFFER_FNS(JBDDirty, jbddirty)
299 TAS_BUFFER_FNS(JBDDirty, jbddirty)
300 BUFFER_FNS(Revoked, revoked)
301 TAS_BUFFER_FNS(Revoked, revoked)
302 BUFFER_FNS(RevokeValid, revokevalid)
303 TAS_BUFFER_FNS(RevokeValid, revokevalid)
304 BUFFER_FNS(Freed, freed)
306 static inline struct buffer_head *jh2bh(struct journal_head *jh)
311 static inline struct journal_head *bh2jh(struct buffer_head *bh)
313 return bh->b_private;
316 static inline void jbd_lock_bh_state(struct buffer_head *bh)
318 bit_spin_lock(BH_State, &bh->b_state);
321 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
323 return bit_spin_trylock(BH_State, &bh->b_state);
326 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
328 return bit_spin_is_locked(BH_State, &bh->b_state);
331 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
333 bit_spin_unlock(BH_State, &bh->b_state);
336 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
338 bit_spin_lock(BH_JournalHead, &bh->b_state);
341 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
343 bit_spin_unlock(BH_JournalHead, &bh->b_state);
346 struct jbd_revoke_table_s;
349 * struct handle_s - this is the concrete type associated with handle_t.
350 * @h_transaction: Which compound transaction is this update a part of?
351 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
352 * @h_ref: Reference count on this handle
353 * @h_err: Field for caller's use to track errors through large fs operations
354 * @h_sync: flag for sync-on-close
355 * @h_jdata: flag to force data journaling
356 * @h_aborted: flag indicating fatal error on handle
357 * @h_lockdep_map: lockdep info for debugging lock problems
361 /* Which compound transaction is this update a part of? */
362 transaction_t *h_transaction;
364 /* Number of remaining buffers we are allowed to dirty: */
365 int h_buffer_credits;
367 /* Reference count on this handle */
370 /* Field for caller's use to track errors through large fs */
374 /* Flags [no locking] */
375 unsigned int h_sync: 1; /* sync-on-close */
376 unsigned int h_jdata: 1; /* force data journaling */
377 unsigned int h_aborted: 1; /* fatal error on handle */
379 #ifdef CONFIG_DEBUG_LOCK_ALLOC
380 struct lockdep_map h_lockdep_map;
385 /* The transaction_t type is the guts of the journaling mechanism. It
386 * tracks a compound transaction through its various states:
388 * RUNNING: accepting new updates
389 * LOCKED: Updates still running but we don't accept new ones
390 * RUNDOWN: Updates are tidying up but have finished requesting
391 * new buffers to modify (state not used for now)
392 * FLUSH: All updates complete, but we are still writing to disk
393 * COMMIT: All data on disk, writing commit record
394 * FINISHED: We still have to keep the transaction for checkpointing.
396 * The transaction keeps track of all of the buffers modified by a
397 * running transaction, and all of the buffers committed but not yet
398 * flushed to home for finished transactions.
405 * ->jbd_lock_bh_journal_head() (This is "innermost")
408 * ->jbd_lock_bh_state()
410 * jbd_lock_bh_state()
417 * ->j_list_lock (journal_unmap_buffer)
423 /* Pointer to the journal for this transaction. [no locking] */
424 journal_t *t_journal;
426 /* Sequence number for this transaction [no locking] */
430 * Transaction's current state
431 * [no locking - only kjournald alters this]
432 * [j_list_lock] guards transition of a transaction into T_FINISHED
433 * state and subsequent call of __journal_drop_transaction()
434 * FIXME: needs barriers
435 * KLUDGE: [use j_state_lock]
447 * Where in the log does this transaction's commit start? [no locking]
449 unsigned long t_log_start;
451 /* Number of buffers on the t_buffers list [j_list_lock] */
455 * Doubly-linked circular list of all buffers reserved but not yet
456 * modified by this transaction [j_list_lock]
458 struct journal_head *t_reserved_list;
461 * Doubly-linked circular list of all buffers under writeout during
462 * commit [j_list_lock]
464 struct journal_head *t_locked_list;
467 * Doubly-linked circular list of all metadata buffers owned by this
468 * transaction [j_list_lock]
470 struct journal_head *t_buffers;
473 * Doubly-linked circular list of all data buffers still to be
474 * flushed before this transaction can be committed [j_list_lock]
476 struct journal_head *t_sync_datalist;
479 * Doubly-linked circular list of all forget buffers (superseded
480 * buffers which we can un-checkpoint once this transaction commits)
483 struct journal_head *t_forget;
486 * Doubly-linked circular list of all buffers still to be flushed before
487 * this transaction can be checkpointed. [j_list_lock]
489 struct journal_head *t_checkpoint_list;
492 * Doubly-linked circular list of all buffers submitted for IO while
493 * checkpointing. [j_list_lock]
495 struct journal_head *t_checkpoint_io_list;
498 * Doubly-linked circular list of temporary buffers currently undergoing
499 * IO in the log [j_list_lock]
501 struct journal_head *t_iobuf_list;
504 * Doubly-linked circular list of metadata buffers being shadowed by log
505 * IO. The IO buffers on the iobuf list and the shadow buffers on this
506 * list match each other one for one at all times. [j_list_lock]
508 struct journal_head *t_shadow_list;
511 * Doubly-linked circular list of control buffers being written to the
514 struct journal_head *t_log_list;
517 * Protects info related to handles
519 spinlock_t t_handle_lock;
522 * Number of outstanding updates running on this transaction
528 * Number of buffers reserved for use by all handles in this transaction
529 * handle but not yet modified. [t_handle_lock]
531 int t_outstanding_credits;
534 * Forward and backward links for the circular list of all transactions
535 * awaiting checkpoint. [j_list_lock]
537 transaction_t *t_cpnext, *t_cpprev;
540 * When will the transaction expire (become due for commit), in jiffies?
543 unsigned long t_expires;
546 * When this transaction started, in nanoseconds [no locking]
548 ktime_t t_start_time;
551 * How many handles used this transaction? [t_handle_lock]
558 * struct journal_s - this is the concrete type associated with journal_t.
559 * @j_flags: General journaling state flags
560 * @j_errno: Is there an outstanding uncleared error on the journal (from a
562 * @j_sb_buffer: First part of superblock buffer
563 * @j_superblock: Second part of superblock buffer
564 * @j_format_version: Version of the superblock format
565 * @j_state_lock: Protect the various scalars in the journal
566 * @j_barrier_count: Number of processes waiting to create a barrier lock
567 * @j_barrier: The barrier lock itself
568 * @j_running_transaction: The current running transaction..
569 * @j_committing_transaction: the transaction we are pushing to disk
570 * @j_checkpoint_transactions: a linked circular list of all transactions
571 * waiting for checkpointing
572 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
573 * to start committing, or for a barrier lock to be released
574 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
575 * @j_wait_done_commit: Wait queue for waiting for commit to complete
576 * @j_wait_checkpoint: Wait queue to trigger checkpointing
577 * @j_wait_commit: Wait queue to trigger commit
578 * @j_wait_updates: Wait queue to wait for updates to complete
579 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
580 * @j_head: Journal head - identifies the first unused block in the journal
581 * @j_tail: Journal tail - identifies the oldest still-used block in the
583 * @j_free: Journal free - how many free blocks are there in the journal?
584 * @j_first: The block number of the first usable block
585 * @j_last: The block number one beyond the last usable block
586 * @j_dev: Device where we store the journal
587 * @j_blocksize: blocksize for the location where we store the journal.
588 * @j_blk_offset: starting block offset for into the device where we store the
590 * @j_fs_dev: Device which holds the client fs. For internal journal this will
592 * @j_maxlen: Total maximum capacity of the journal region on disk.
593 * @j_list_lock: Protects the buffer lists and internal buffer state.
594 * @j_inode: Optional inode where we store the journal. If present, all journal
595 * block numbers are mapped into this inode via bmap().
596 * @j_tail_sequence: Sequence number of the oldest transaction in the log
597 * @j_transaction_sequence: Sequence number of the next transaction to grant
598 * @j_commit_sequence: Sequence number of the most recently committed
600 * @j_commit_request: Sequence number of the most recent transaction wanting
602 * @j_uuid: Uuid of client object.
603 * @j_task: Pointer to the current commit thread for this journal
604 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
605 * single compound commit transaction
606 * @j_commit_interval: What is the maximum transaction lifetime before we begin
608 * @j_commit_timer: The timer used to wakeup the commit thread
609 * @j_revoke_lock: Protect the revoke table
610 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
611 * current transaction.
612 * @j_revoke_table: alternate revoke tables for j_revoke
613 * @j_wbuf: array of buffer_heads for journal_commit_transaction
614 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
615 * number that will fit in j_blocksize
616 * @j_last_sync_writer: most recent pid which did a synchronous write
617 * @j_average_commit_time: the average amount of time in nanoseconds it
618 * takes to commit a transaction to the disk.
619 * @j_private: An opaque pointer to fs-private information.
624 /* General journaling state flags [j_state_lock] */
625 unsigned long j_flags;
628 * Is there an outstanding uncleared error on the journal (from a prior
629 * abort)? [j_state_lock]
633 /* The superblock buffer */
634 struct buffer_head *j_sb_buffer;
635 journal_superblock_t *j_superblock;
637 /* Version of the superblock format */
638 int j_format_version;
641 * Protect the various scalars in the journal
643 spinlock_t j_state_lock;
646 * Number of processes waiting to create a barrier lock [j_state_lock]
650 /* The barrier lock itself */
651 struct mutex j_barrier;
654 * Transactions: The current running transaction...
655 * [j_state_lock] [caller holding open handle]
657 transaction_t *j_running_transaction;
660 * the transaction we are pushing to disk
661 * [j_state_lock] [caller holding open handle]
663 transaction_t *j_committing_transaction;
666 * ... and a linked circular list of all transactions waiting for
667 * checkpointing. [j_list_lock]
669 transaction_t *j_checkpoint_transactions;
672 * Wait queue for waiting for a locked transaction to start committing,
673 * or for a barrier lock to be released
675 wait_queue_head_t j_wait_transaction_locked;
677 /* Wait queue for waiting for checkpointing to complete */
678 wait_queue_head_t j_wait_logspace;
680 /* Wait queue for waiting for commit to complete */
681 wait_queue_head_t j_wait_done_commit;
683 /* Wait queue to trigger checkpointing */
684 wait_queue_head_t j_wait_checkpoint;
686 /* Wait queue to trigger commit */
687 wait_queue_head_t j_wait_commit;
689 /* Wait queue to wait for updates to complete */
690 wait_queue_head_t j_wait_updates;
692 /* Semaphore for locking against concurrent checkpoints */
693 struct mutex j_checkpoint_mutex;
696 * Journal head: identifies the first unused block in the journal.
699 unsigned long j_head;
702 * Journal tail: identifies the oldest still-used block in the journal.
705 unsigned long j_tail;
708 * Journal free: how many free blocks are there in the journal?
711 unsigned long j_free;
714 * Journal start and end: the block numbers of the first usable block
715 * and one beyond the last usable block in the journal. [j_state_lock]
717 unsigned long j_first;
718 unsigned long j_last;
721 * Device, blocksize and starting block offset for the location where we
724 struct block_device *j_dev;
726 unsigned long j_blk_offset;
729 * Device which holds the client fs. For internal journal this will be
732 struct block_device *j_fs_dev;
734 /* Total maximum capacity of the journal region on disk. */
735 unsigned int j_maxlen;
738 * Protects the buffer lists and internal buffer state.
740 spinlock_t j_list_lock;
742 /* Optional inode where we store the journal. If present, all */
743 /* journal block numbers are mapped into this inode via */
745 struct inode *j_inode;
748 * Sequence number of the oldest transaction in the log [j_state_lock]
750 tid_t j_tail_sequence;
753 * Sequence number of the next transaction to grant [j_state_lock]
755 tid_t j_transaction_sequence;
758 * Sequence number of the most recently committed transaction
761 tid_t j_commit_sequence;
764 * Sequence number of the most recent transaction wanting commit
767 tid_t j_commit_request;
770 * Journal uuid: identifies the object (filesystem, LVM volume etc)
771 * backed by this journal. This will eventually be replaced by an array
772 * of uuids, allowing us to index multiple devices within a single
773 * journal and to perform atomic updates across them.
777 /* Pointer to the current commit thread for this journal */
778 struct task_struct *j_task;
781 * Maximum number of metadata buffers to allow in a single compound
784 int j_max_transaction_buffers;
787 * What is the maximum transaction lifetime before we begin a commit?
789 unsigned long j_commit_interval;
791 /* The timer used to wakeup the commit thread: */
792 struct timer_list j_commit_timer;
795 * The revoke table: maintains the list of revoked blocks in the
796 * current transaction. [j_revoke_lock]
798 spinlock_t j_revoke_lock;
799 struct jbd_revoke_table_s *j_revoke;
800 struct jbd_revoke_table_s *j_revoke_table[2];
803 * array of bhs for journal_commit_transaction
805 struct buffer_head **j_wbuf;
809 * this is the pid of the last person to run a synchronous operation
810 * through the journal.
812 pid_t j_last_sync_writer;
815 * the average amount of time in nanoseconds it takes to commit a
816 * transaction to the disk. [j_state_lock]
818 u64 j_average_commit_time;
821 * An opaque pointer to fs-private information. ext3 puts its
822 * superblock pointer here
828 * Journal flag definitions
830 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
831 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
832 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
833 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
834 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
835 #define JFS_BARRIER 0x020 /* Use IDE barriers */
836 #define JFS_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
837 * data write error in ordered
841 * Function declarations for the journaling transaction and buffer
846 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
847 extern void __journal_unfile_buffer(struct journal_head *);
848 extern void __journal_refile_buffer(struct journal_head *);
849 extern void journal_refile_buffer(journal_t *, struct journal_head *);
850 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
851 extern void __journal_free_buffer(struct journal_head *bh);
852 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
853 extern void __journal_clean_data_list(transaction_t *transaction);
855 /* Log buffer allocation */
856 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
857 int journal_next_log_block(journal_t *, unsigned long *);
859 /* Commit management */
860 extern void journal_commit_transaction(journal_t *);
862 /* Checkpoint list management */
863 int __journal_clean_checkpoint_list(journal_t *journal);
864 int __journal_remove_checkpoint(struct journal_head *);
865 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
869 journal_write_metadata_buffer(transaction_t *transaction,
870 struct journal_head *jh_in,
871 struct journal_head **jh_out,
872 unsigned long blocknr);
874 /* Transaction locking */
875 extern void __wait_on_journal (journal_t *);
880 * We need to lock the journal during transaction state changes so that nobody
881 * ever tries to take a handle on the running transaction while we are in the
882 * middle of moving it to the commit phase. j_state_lock does this.
884 * Note that the locking is completely interrupt unsafe. We never touch
885 * journal structures from interrupts.
888 static inline handle_t *journal_current_handle(void)
890 return current->journal_info;
893 /* The journaling code user interface:
895 * Create and destroy handles
896 * Register buffer modifications against the current transaction.
899 extern handle_t *journal_start(journal_t *, int nblocks);
900 extern int journal_restart (handle_t *, int nblocks);
901 extern int journal_extend (handle_t *, int nblocks);
902 extern int journal_get_write_access(handle_t *, struct buffer_head *);
903 extern int journal_get_create_access (handle_t *, struct buffer_head *);
904 extern int journal_get_undo_access(handle_t *, struct buffer_head *);
905 extern int journal_dirty_data (handle_t *, struct buffer_head *);
906 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
907 extern void journal_release_buffer (handle_t *, struct buffer_head *);
908 extern int journal_forget (handle_t *, struct buffer_head *);
909 extern void journal_sync_buffer (struct buffer_head *);
910 extern void journal_invalidatepage(journal_t *,
911 struct page *, unsigned long);
912 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
913 extern int journal_stop(handle_t *);
914 extern int journal_flush (journal_t *);
915 extern void journal_lock_updates (journal_t *);
916 extern void journal_unlock_updates (journal_t *);
918 extern journal_t * journal_init_dev(struct block_device *bdev,
919 struct block_device *fs_dev,
920 int start, int len, int bsize);
921 extern journal_t * journal_init_inode (struct inode *);
922 extern int journal_update_format (journal_t *);
923 extern int journal_check_used_features
924 (journal_t *, unsigned long, unsigned long, unsigned long);
925 extern int journal_check_available_features
926 (journal_t *, unsigned long, unsigned long, unsigned long);
927 extern int journal_set_features
928 (journal_t *, unsigned long, unsigned long, unsigned long);
929 extern int journal_create (journal_t *);
930 extern int journal_load (journal_t *journal);
931 extern int journal_destroy (journal_t *);
932 extern int journal_recover (journal_t *journal);
933 extern int journal_wipe (journal_t *, int);
934 extern int journal_skip_recovery (journal_t *);
935 extern void journal_update_superblock (journal_t *, int);
936 extern void journal_abort (journal_t *, int);
937 extern int journal_errno (journal_t *);
938 extern void journal_ack_err (journal_t *);
939 extern int journal_clear_err (journal_t *);
940 extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
941 extern int journal_force_commit(journal_t *);
944 * journal_head management
946 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
947 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
948 void journal_remove_journal_head(struct buffer_head *bh);
949 void journal_put_journal_head(struct journal_head *jh);
954 extern struct kmem_cache *jbd_handle_cache;
956 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
958 return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
961 static inline void jbd_free_handle(handle_t *handle)
963 kmem_cache_free(jbd_handle_cache, handle);
966 /* Primary revoke support */
967 #define JOURNAL_REVOKE_DEFAULT_HASH 256
968 extern int journal_init_revoke(journal_t *, int);
969 extern void journal_destroy_revoke_caches(void);
970 extern int journal_init_revoke_caches(void);
972 extern void journal_destroy_revoke(journal_t *);
973 extern int journal_revoke (handle_t *,
974 unsigned long, struct buffer_head *);
975 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
976 extern void journal_write_revoke_records(journal_t *, transaction_t *);
978 /* Recovery revoke support */
979 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
980 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
981 extern void journal_clear_revoke(journal_t *);
982 extern void journal_switch_revoke_table(journal_t *journal);
985 * The log thread user interface:
987 * Request space in the current transaction, and force transaction commit
988 * transitions on demand.
991 int __log_space_left(journal_t *); /* Called with journal locked */
992 int log_start_commit(journal_t *journal, tid_t tid);
993 int __log_start_commit(journal_t *journal, tid_t tid);
994 int journal_start_commit(journal_t *journal, tid_t *tid);
995 int journal_force_commit_nested(journal_t *journal);
996 int log_wait_commit(journal_t *journal, tid_t tid);
997 int log_do_checkpoint(journal_t *journal);
999 void __log_wait_for_space(journal_t *journal);
1000 extern void __journal_drop_transaction(journal_t *, transaction_t *);
1001 extern int cleanup_journal_tail(journal_t *);
1003 /* Debugging code only: */
1005 #define jbd_ENOSYS() \
1007 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \
1008 current->state = TASK_UNINTERRUPTIBLE; \
1015 * Simple test wrapper function to test the JFS_ABORT state flag. This
1016 * bit, when set, indicates that we have had a fatal error somewhere,
1017 * either inside the journaling layer or indicated to us by the client
1018 * (eg. ext3), and that we and should not commit any further
1022 static inline int is_journal_aborted(journal_t *journal)
1024 return journal->j_flags & JFS_ABORT;
1027 static inline int is_handle_aborted(handle_t *handle)
1029 if (handle->h_aborted)
1031 return is_journal_aborted(handle->h_transaction->t_journal);
1034 static inline void journal_abort_handle(handle_t *handle)
1036 handle->h_aborted = 1;
1039 #endif /* __KERNEL__ */
1041 /* Comparison functions for transaction IDs: perform comparisons using
1042 * modulo arithmetic so that they work over sequence number wraps. */
1044 static inline int tid_gt(tid_t x, tid_t y)
1046 int difference = (x - y);
1047 return (difference > 0);
1050 static inline int tid_geq(tid_t x, tid_t y)
1052 int difference = (x - y);
1053 return (difference >= 0);
1056 extern int journal_blocks_per_page(struct inode *inode);
1059 * Return the minimum number of blocks which must be free in the journal
1060 * before a new transaction may be started. Must be called under j_state_lock.
1062 static inline int jbd_space_needed(journal_t *journal)
1064 int nblocks = journal->j_max_transaction_buffers;
1065 if (journal->j_committing_transaction)
1066 nblocks += journal->j_committing_transaction->
1067 t_outstanding_credits;
1072 * Definitions which augment the buffer_head layer
1075 /* journaling buffer types */
1076 #define BJ_None 0 /* Not journaled */
1077 #define BJ_SyncData 1 /* Normal data: flush before commit */
1078 #define BJ_Metadata 2 /* Normal journaled metadata */
1079 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1080 #define BJ_IO 4 /* Buffer is for temporary IO use */
1081 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1082 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1083 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1084 #define BJ_Locked 8 /* Locked for I/O during commit */
1087 extern int jbd_blocks_per_page(struct inode *inode);
1091 #define buffer_trace_init(bh) do {} while (0)
1092 #define print_buffer_fields(bh) do {} while (0)
1093 #define print_buffer_trace(bh) do {} while (0)
1094 #define BUFFER_TRACE(bh, info) do {} while (0)
1095 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1096 #define JBUFFER_TRACE(jh, info) do {} while (0)
1098 #endif /* __KERNEL__ */
1100 #endif /* _LINUX_JBD_H */