2 * linux/include/linux/jbd.h
4 * Written by Stephen C. Tweedie <sct@redhat.com>
6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
12 * Definitions for transaction data structures for the buffer cache
13 * filesystem journaling support.
19 #if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__)
21 /* Allow this file to be included directly into e2fsprogs */
23 #include "jfs_compat.h"
25 #define jfs_debug jbd_debug
28 #include <linux/buffer_head.h>
29 #include <linux/journal-head.h>
30 #include <linux/stddef.h>
31 #include <asm/semaphore.h>
34 #define journal_oom_retry 1
37 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
38 * certain classes of error which can occur due to failed IOs. Under
39 * normal use we want ext3 to continue after such errors, because
40 * hardware _can_ fail, but for debugging purposes when running tests on
41 * known-good hardware we may want to trap these errors.
43 #undef JBD_PARANOID_IOFAIL
46 * The default maximum commit age, in seconds.
48 #define JBD_DEFAULT_MAX_COMMIT_AGE 5
50 #ifdef CONFIG_JBD_DEBUG
52 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
53 * consistency checks. By default we don't do this unless
54 * CONFIG_JBD_DEBUG is on.
56 #define JBD_EXPENSIVE_CHECKING
57 extern int journal_enable_debug;
59 #define jbd_debug(n, f, a...) \
61 if ((n) <= journal_enable_debug) { \
62 printk (KERN_DEBUG "(%s, %d): %s: ", \
63 __FILE__, __LINE__, __FUNCTION__); \
68 #define jbd_debug(f, a...) /**/
71 extern void * __jbd_kmalloc (const char *where, size_t size, int flags, int retry);
72 #define jbd_kmalloc(size, flags) \
73 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
74 #define jbd_rep_kmalloc(size, flags) \
75 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
77 #define JFS_MIN_JOURNAL_BLOCKS 1024
82 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
84 * All filesystem modifications made by the process go
85 * through this handle. Recursive operations (such as quota operations)
86 * are gathered into a single update.
88 * The buffer credits field is used to account for journaled buffers
89 * being modified by the running process. To ensure that there is
90 * enough log space for all outstanding operations, we need to limit the
91 * number of outstanding buffers possible at any time. When the
92 * operation completes, any buffer credits not used are credited back to
93 * the transaction, so that at all times we know how many buffers the
94 * outstanding updates on a transaction might possibly touch.
96 * This is an opaque datatype.
98 typedef struct handle_s handle_t; /* Atomic operation type */
102 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
104 * journal_t is linked to from the fs superblock structure.
106 * We use the journal_t to keep track of all outstanding transaction
107 * activity on the filesystem, and to manage the state of the log
110 * This is an opaque datatype.
112 typedef struct journal_s journal_t; /* Journal control structure */
116 * Internal structures used by the logging mechanism:
119 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
126 * Descriptor block types:
129 #define JFS_DESCRIPTOR_BLOCK 1
130 #define JFS_COMMIT_BLOCK 2
131 #define JFS_SUPERBLOCK_V1 3
132 #define JFS_SUPERBLOCK_V2 4
133 #define JFS_REVOKE_BLOCK 5
136 * Standard header for all descriptor blocks:
138 typedef struct journal_header_s
147 * The block tag: used to describe a single buffer in the journal
149 typedef struct journal_block_tag_s
151 __be32 t_blocknr; /* The on-disk block number */
152 __be32 t_flags; /* See below */
153 } journal_block_tag_t;
156 * The revoke descriptor: used on disk to describe a series of blocks to
157 * be revoked from the log
159 typedef struct journal_revoke_header_s
161 journal_header_t r_header;
162 __be32 r_count; /* Count of bytes used in the block */
163 } journal_revoke_header_t;
166 /* Definitions for the journal tag flags word: */
167 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
168 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
169 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
170 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
174 * The journal superblock. All fields are in big-endian byte order.
176 typedef struct journal_superblock_s
179 journal_header_t s_header;
182 /* Static information describing the journal */
183 __be32 s_blocksize; /* journal device blocksize */
184 __be32 s_maxlen; /* total blocks in journal file */
185 __be32 s_first; /* first block of log information */
188 /* Dynamic information describing the current state of the log */
189 __be32 s_sequence; /* first commit ID expected in log */
190 __be32 s_start; /* blocknr of start of log */
193 /* Error value, as set by journal_abort(). */
197 /* Remaining fields are only valid in a version-2 superblock */
198 __be32 s_feature_compat; /* compatible feature set */
199 __be32 s_feature_incompat; /* incompatible feature set */
200 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
202 __u8 s_uuid[16]; /* 128-bit uuid for journal */
205 __be32 s_nr_users; /* Nr of filesystems sharing log */
207 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
210 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
211 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
217 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
219 } journal_superblock_t;
221 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
222 ((j)->j_format_version >= 2 && \
223 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
224 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
225 ((j)->j_format_version >= 2 && \
226 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
227 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
228 ((j)->j_format_version >= 2 && \
229 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
231 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
233 /* Features known to this kernel version: */
234 #define JFS_KNOWN_COMPAT_FEATURES 0
235 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
236 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
240 #include <linux/fs.h>
241 #include <linux/sched.h>
244 #define JBD_ASSERTIONS
245 #ifdef JBD_ASSERTIONS
246 #define J_ASSERT(assert) \
250 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
251 __FUNCTION__, __FILE__, __LINE__, # assert); \
256 #if defined(CONFIG_BUFFER_DEBUG)
257 void buffer_assertion_failure(struct buffer_head *bh);
258 #define J_ASSERT_BH(bh, expr) \
261 buffer_assertion_failure(bh); \
264 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
266 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
267 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
271 #define J_ASSERT(assert) do { } while (0)
272 #endif /* JBD_ASSERTIONS */
274 #if defined(JBD_PARANOID_IOFAIL)
275 #define J_EXPECT(expr, why...) J_ASSERT(expr)
276 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
277 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
279 #define __journal_expect(expr, why...) \
284 "EXT3-fs unexpected failure: %s;\n",# expr); \
285 printk(KERN_ERR why "\n"); \
289 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
290 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
291 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
294 enum jbd_state_bits {
295 BH_JBD /* Has an attached ext3 journal_head */
297 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
298 BH_Freed, /* Has been freed (truncated) */
299 BH_Revoked, /* Has been revoked from the log */
300 BH_RevokeValid, /* Revoked flag is valid */
301 BH_JBDDirty, /* Is dirty but journaled */
302 BH_State, /* Pins most journal_head state */
303 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
307 BUFFER_FNS(JWrite, jwrite)
308 BUFFER_FNS(JBDDirty, jbddirty)
309 TAS_BUFFER_FNS(JBDDirty, jbddirty)
310 BUFFER_FNS(Revoked, revoked)
311 TAS_BUFFER_FNS(Revoked, revoked)
312 BUFFER_FNS(RevokeValid, revokevalid)
313 TAS_BUFFER_FNS(RevokeValid, revokevalid)
314 BUFFER_FNS(Freed, freed)
316 static inline struct buffer_head *jh2bh(struct journal_head *jh)
321 static inline struct journal_head *bh2jh(struct buffer_head *bh)
323 return bh->b_private;
326 static inline void jbd_lock_bh_state(struct buffer_head *bh)
328 bit_spin_lock(BH_State, &bh->b_state);
331 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
333 return bit_spin_trylock(BH_State, &bh->b_state);
336 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
338 return bit_spin_is_locked(BH_State, &bh->b_state);
341 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
343 bit_spin_unlock(BH_State, &bh->b_state);
346 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
348 bit_spin_lock(BH_JournalHead, &bh->b_state);
351 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
353 bit_spin_unlock(BH_JournalHead, &bh->b_state);
356 #define HAVE_JOURNAL_CALLBACK_STATUS
358 * struct journal_callback - Base structure for callback information.
359 * @jcb_list: list information for other callbacks attached to the same handle.
360 * @jcb_func: Function to call with this callback structure.
362 * This struct is a 'seed' structure for a using with your own callback
363 * structs. If you are using callbacks you must allocate one of these
364 * or another struct of your own definition which has this struct
365 * as it's first element and pass it to journal_callback_set().
367 * This is used internally by jbd to maintain callback information.
369 * See journal_callback_set for more information.
371 struct journal_callback {
372 struct list_head jcb_list; /* t_jcb_lock */
373 void (*jcb_func)(struct journal_callback *jcb, int error);
374 /* user data goes here */
377 struct jbd_revoke_table_s;
380 * struct handle_s - The handle_s type is the concrete type associated with
382 * @h_transaction: Which compound transaction is this update a part of?
383 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
384 * @h_ref: Reference count on this handle
385 * @h_jcb: List of application registered callbacks for this handle.
386 * @h_err: Field for caller's use to track errors through large fs operations
387 * @h_sync: flag for sync-on-close
388 * @h_jdata: flag to force data journaling
389 * @h_aborted: flag indicating fatal error on handle
392 /* Docbook can't yet cope with the bit fields, but will leave the documentation
393 * in so it can be fixed later.
398 /* Which compound transaction is this update a part of? */
399 transaction_t *h_transaction;
401 /* Number of remaining buffers we are allowed to dirty: */
402 int h_buffer_credits;
404 /* Reference count on this handle */
407 /* Field for caller's use to track errors through large fs */
412 * List of application registered callbacks for this handle. The
413 * function(s) will be called after the transaction that this handle is
414 * part of has been committed to disk. [t_jcb_lock]
416 struct list_head h_jcb;
418 /* Flags [no locking] */
419 unsigned int h_sync: 1; /* sync-on-close */
420 unsigned int h_jdata: 1; /* force data journaling */
421 unsigned int h_aborted: 1; /* fatal error on handle */
425 /* The transaction_t type is the guts of the journaling mechanism. It
426 * tracks a compound transaction through its various states:
428 * RUNNING: accepting new updates
429 * LOCKED: Updates still running but we don't accept new ones
430 * RUNDOWN: Updates are tidying up but have finished requesting
431 * new buffers to modify (state not used for now)
432 * FLUSH: All updates complete, but we are still writing to disk
433 * COMMIT: All data on disk, writing commit record
434 * FINISHED: We still have to keep the transaction for checkpointing.
436 * The transaction keeps track of all of the buffers modified by a
437 * running transaction, and all of the buffers committed but not yet
438 * flushed to home for finished transactions.
445 * ->jbd_lock_bh_journal_head() (This is "innermost")
448 * ->jbd_lock_bh_state()
450 * jbd_lock_bh_state()
457 * ->j_list_lock (journal_unmap_buffer)
465 /* Pointer to the journal for this transaction. [no locking] */
466 journal_t *t_journal;
468 /* Sequence number for this transaction [no locking] */
472 * Transaction's current state
473 * [no locking - only kjournald alters this]
474 * FIXME: needs barriers
475 * KLUDGE: [use j_state_lock]
487 * Where in the log does this transaction's commit start? [no locking]
489 unsigned long t_log_start;
491 /* Number of buffers on the t_buffers list [j_list_lock] */
495 * Doubly-linked circular list of all buffers reserved but not yet
496 * modified by this transaction [j_list_lock]
498 struct journal_head *t_reserved_list;
501 * Doubly-linked circular list of all buffers under writeout during
502 * commit [j_list_lock]
504 struct journal_head *t_locked_list;
507 * Doubly-linked circular list of all metadata buffers owned by this
508 * transaction [j_list_lock]
510 struct journal_head *t_buffers;
513 * Doubly-linked circular list of all data buffers still to be
514 * flushed before this transaction can be committed [j_list_lock]
516 struct journal_head *t_sync_datalist;
519 * Doubly-linked circular list of all forget buffers (superseded
520 * buffers which we can un-checkpoint once this transaction commits)
523 struct journal_head *t_forget;
526 * Doubly-linked circular list of all buffers still to be flushed before
527 * this transaction can be checkpointed. [j_list_lock]
529 struct journal_head *t_checkpoint_list;
532 * Doubly-linked circular list of temporary buffers currently undergoing
533 * IO in the log [j_list_lock]
535 struct journal_head *t_iobuf_list;
538 * Doubly-linked circular list of metadata buffers being shadowed by log
539 * IO. The IO buffers on the iobuf list and the shadow buffers on this
540 * list match each other one for one at all times. [j_list_lock]
542 struct journal_head *t_shadow_list;
545 * Doubly-linked circular list of control buffers being written to the
548 struct journal_head *t_log_list;
551 * Protects info related to handles
553 spinlock_t t_handle_lock;
556 * Number of outstanding updates running on this transaction
562 * Number of buffers reserved for use by all handles in this transaction
563 * handle but not yet modified. [t_handle_lock]
565 int t_outstanding_credits;
568 * Forward and backward links for the circular list of all transactions
569 * awaiting checkpoint. [j_list_lock]
571 transaction_t *t_cpnext, *t_cpprev;
574 * When will the transaction expire (become due for commit), in jiffies?
577 unsigned long t_expires;
580 * How many handles used this transaction? [t_handle_lock]
585 * Protects the callback list
587 spinlock_t t_jcb_lock;
589 * List of registered callback functions for this transaction.
590 * Called when the transaction is committed. [t_jcb_lock]
592 struct list_head t_jcb;
596 * struct journal_s - The journal_s type is the concrete type associated with
598 * @j_flags: General journaling state flags
599 * @j_errno: Is there an outstanding uncleared error on the journal (from a
601 * @j_sb_buffer: First part of superblock buffer
602 * @j_superblock: Second part of superblock buffer
603 * @j_format_version: Version of the superblock format
604 * @j_barrier_count: Number of processes waiting to create a barrier lock
605 * @j_barrier: The barrier lock itself
606 * @j_running_transaction: The current running transaction..
607 * @j_committing_transaction: the transaction we are pushing to disk
608 * @j_checkpoint_transactions: a linked circular list of all transactions
609 * waiting for checkpointing
610 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
611 * to start committing, or for a barrier lock to be released
612 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
613 * @j_wait_done_commit: Wait queue for waiting for commit to complete
614 * @j_wait_checkpoint: Wait queue to trigger checkpointing
615 * @j_wait_commit: Wait queue to trigger commit
616 * @j_wait_updates: Wait queue to wait for updates to complete
617 * @j_checkpoint_sem: Semaphore for locking against concurrent checkpoints
618 * @j_head: Journal head - identifies the first unused block in the journal
619 * @j_tail: Journal tail - identifies the oldest still-used block in the
621 * @j_free: Journal free - how many free blocks are there in the journal?
622 * @j_first: The block number of the first usable block
623 * @j_last: The block number one beyond the last usable block
624 * @j_dev: Device where we store the journal
625 * @j_blocksize: blocksize for the location where we store the journal.
626 * @j_blk_offset: starting block offset for into the device where we store the
628 * @j_fs_dev: Device which holds the client fs. For internal journal this will
630 * @j_maxlen: Total maximum capacity of the journal region on disk.
631 * @j_inode: Optional inode where we store the journal. If present, all journal
632 * block numbers are mapped into this inode via bmap().
633 * @j_tail_sequence: Sequence number of the oldest transaction in the log
634 * @j_transaction_sequence: Sequence number of the next transaction to grant
635 * @j_commit_sequence: Sequence number of the most recently committed
637 * @j_commit_request: Sequence number of the most recent transaction wanting
639 * @j_uuid: Uuid of client object.
640 * @j_task: Pointer to the current commit thread for this journal
641 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
642 * single compound commit transaction
643 * @j_commit_interval: What is the maximum transaction lifetime before we begin
645 * @j_commit_timer: The timer used to wakeup the commit thread
646 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
647 * current transaction.
652 /* General journaling state flags [j_state_lock] */
653 unsigned long j_flags;
656 * Is there an outstanding uncleared error on the journal (from a prior
657 * abort)? [j_state_lock]
661 /* The superblock buffer */
662 struct buffer_head *j_sb_buffer;
663 journal_superblock_t *j_superblock;
665 /* Version of the superblock format */
666 int j_format_version;
669 * Protect the various scalars in the journal
671 spinlock_t j_state_lock;
674 * Number of processes waiting to create a barrier lock [j_state_lock]
678 /* The barrier lock itself */
679 struct semaphore j_barrier;
682 * Transactions: The current running transaction...
683 * [j_state_lock] [caller holding open handle]
685 transaction_t *j_running_transaction;
688 * the transaction we are pushing to disk
689 * [j_state_lock] [caller holding open handle]
691 transaction_t *j_committing_transaction;
694 * ... and a linked circular list of all transactions waiting for
695 * checkpointing. [j_list_lock]
697 transaction_t *j_checkpoint_transactions;
700 * Wait queue for waiting for a locked transaction to start committing,
701 * or for a barrier lock to be released
703 wait_queue_head_t j_wait_transaction_locked;
705 /* Wait queue for waiting for checkpointing to complete */
706 wait_queue_head_t j_wait_logspace;
708 /* Wait queue for waiting for commit to complete */
709 wait_queue_head_t j_wait_done_commit;
711 /* Wait queue to trigger checkpointing */
712 wait_queue_head_t j_wait_checkpoint;
714 /* Wait queue to trigger commit */
715 wait_queue_head_t j_wait_commit;
717 /* Wait queue to wait for updates to complete */
718 wait_queue_head_t j_wait_updates;
720 /* Semaphore for locking against concurrent checkpoints */
721 struct semaphore j_checkpoint_sem;
724 * Journal head: identifies the first unused block in the journal.
727 unsigned long j_head;
730 * Journal tail: identifies the oldest still-used block in the journal.
733 unsigned long j_tail;
736 * Journal free: how many free blocks are there in the journal?
739 unsigned long j_free;
742 * Journal start and end: the block numbers of the first usable block
743 * and one beyond the last usable block in the journal. [j_state_lock]
745 unsigned long j_first;
746 unsigned long j_last;
749 * Device, blocksize and starting block offset for the location where we
752 struct block_device *j_dev;
754 unsigned int j_blk_offset;
757 * Device which holds the client fs. For internal journal this will be
760 struct block_device *j_fs_dev;
762 /* Total maximum capacity of the journal region on disk. */
763 unsigned int j_maxlen;
766 * Protects the buffer lists and internal buffer state.
768 spinlock_t j_list_lock;
770 /* Optional inode where we store the journal. If present, all */
771 /* journal block numbers are mapped into this inode via */
773 struct inode *j_inode;
776 * Sequence number of the oldest transaction in the log [j_state_lock]
778 tid_t j_tail_sequence;
781 * Sequence number of the next transaction to grant [j_state_lock]
783 tid_t j_transaction_sequence;
786 * Sequence number of the most recently committed transaction
789 tid_t j_commit_sequence;
792 * Sequence number of the most recent transaction wanting commit
795 tid_t j_commit_request;
798 * Journal uuid: identifies the object (filesystem, LVM volume etc)
799 * backed by this journal. This will eventually be replaced by an array
800 * of uuids, allowing us to index multiple devices within a single
801 * journal and to perform atomic updates across them.
805 /* Pointer to the current commit thread for this journal */
806 struct task_struct *j_task;
809 * Maximum number of metadata buffers to allow in a single compound
812 int j_max_transaction_buffers;
815 * What is the maximum transaction lifetime before we begin a commit?
817 unsigned long j_commit_interval;
819 /* The timer used to wakeup the commit thread: */
820 struct timer_list *j_commit_timer;
823 * The revoke table: maintains the list of revoked blocks in the
824 * current transaction. [j_revoke_lock]
826 spinlock_t j_revoke_lock;
827 struct jbd_revoke_table_s *j_revoke;
828 struct jbd_revoke_table_s *j_revoke_table[2];
831 * An opaque pointer to fs-private information. ext3 puts its
832 * superblock pointer here
838 * Journal flag definitions
840 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
841 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
842 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
843 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
844 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
845 #define JFS_BARRIER 0x020 /* Use IDE barriers */
848 * Function declarations for the journaling transaction and buffer
853 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
854 extern void __journal_unfile_buffer(struct journal_head *);
855 extern void __journal_refile_buffer(struct journal_head *);
856 extern void journal_refile_buffer(journal_t *, struct journal_head *);
857 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
858 extern void __journal_free_buffer(struct journal_head *bh);
859 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
860 extern void __journal_clean_data_list(transaction_t *transaction);
862 /* Log buffer allocation */
863 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
864 int journal_next_log_block(journal_t *, unsigned long *);
866 /* Commit management */
867 extern void journal_commit_transaction(journal_t *);
869 /* Checkpoint list management */
870 int __journal_clean_checkpoint_list(journal_t *journal);
871 void __journal_remove_checkpoint(struct journal_head *);
872 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
876 journal_write_metadata_buffer(transaction_t *transaction,
877 struct journal_head *jh_in,
878 struct journal_head **jh_out,
881 /* Transaction locking */
882 extern void __wait_on_journal (journal_t *);
887 * We need to lock the journal during transaction state changes so that nobody
888 * ever tries to take a handle on the running transaction while we are in the
889 * middle of moving it to the commit phase. j_state_lock does this.
891 * Note that the locking is completely interrupt unsafe. We never touch
892 * journal structures from interrupts.
895 static inline handle_t *journal_current_handle(void)
897 return current->journal_info;
900 /* The journaling code user interface:
902 * Create and destroy handles
903 * Register buffer modifications against the current transaction.
906 extern handle_t *journal_start(journal_t *, int nblocks);
907 extern int journal_restart (handle_t *, int nblocks);
908 extern int journal_extend (handle_t *, int nblocks);
909 extern int journal_get_write_access(handle_t *, struct buffer_head *,
911 extern int journal_get_create_access (handle_t *, struct buffer_head *);
912 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 *,
918 extern int journal_forget (handle_t *, struct buffer_head *);
919 extern void journal_sync_buffer (struct buffer_head *);
920 extern int journal_invalidatepage(journal_t *,
921 struct page *, unsigned long);
922 extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
923 extern int journal_stop(handle_t *);
924 extern int journal_flush (journal_t *);
925 extern void journal_callback_set(handle_t *handle,
926 void (*fn)(struct journal_callback *,int),
927 struct journal_callback *jcb);
929 extern void journal_lock_updates (journal_t *);
930 extern void journal_unlock_updates (journal_t *);
932 extern journal_t * journal_init_dev(struct block_device *bdev,
933 struct block_device *fs_dev,
934 int start, int len, int bsize);
935 extern journal_t * journal_init_inode (struct inode *);
936 extern int journal_update_format (journal_t *);
937 extern int journal_check_used_features
938 (journal_t *, unsigned long, unsigned long, unsigned long);
939 extern int journal_check_available_features
940 (journal_t *, unsigned long, unsigned long, unsigned long);
941 extern int journal_set_features
942 (journal_t *, unsigned long, unsigned long, unsigned long);
943 extern int journal_create (journal_t *);
944 extern int journal_load (journal_t *journal);
945 extern void journal_destroy (journal_t *);
946 extern int journal_recover (journal_t *journal);
947 extern int journal_wipe (journal_t *, int);
948 extern int journal_skip_recovery (journal_t *);
949 extern void journal_update_superblock (journal_t *, int);
950 extern void __journal_abort_hard (journal_t *);
951 extern void __journal_abort_soft (journal_t *, int);
952 extern void journal_abort (journal_t *, int);
953 extern int journal_errno (journal_t *);
954 extern void journal_ack_err (journal_t *);
955 extern int journal_clear_err (journal_t *);
956 extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
957 extern int journal_force_commit(journal_t *);
960 * journal_head management
962 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
963 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
964 void journal_remove_journal_head(struct buffer_head *bh);
965 void journal_put_journal_head(struct journal_head *jh);
970 extern kmem_cache_t *jbd_handle_cache;
972 static inline handle_t *jbd_alloc_handle(int gfp_flags)
974 return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
977 static inline void jbd_free_handle(handle_t *handle)
979 kmem_cache_free(jbd_handle_cache, handle);
982 /* Primary revoke support */
983 #define JOURNAL_REVOKE_DEFAULT_HASH 256
984 extern int journal_init_revoke(journal_t *, int);
985 extern void journal_destroy_revoke_caches(void);
986 extern int journal_init_revoke_caches(void);
988 extern void journal_destroy_revoke(journal_t *);
989 extern int journal_revoke (handle_t *,
990 unsigned long, struct buffer_head *);
991 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
992 extern void journal_write_revoke_records(journal_t *, transaction_t *);
994 /* Recovery revoke support */
995 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
996 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
997 extern void journal_clear_revoke(journal_t *);
998 extern void journal_brelse_array(struct buffer_head *b[], int n);
999 extern void journal_switch_revoke_table(journal_t *journal);
1002 * The log thread user interface:
1004 * Request space in the current transaction, and force transaction commit
1005 * transitions on demand.
1008 int __log_space_left(journal_t *); /* Called with journal locked */
1009 int log_start_commit(journal_t *journal, tid_t tid);
1010 int __log_start_commit(journal_t *journal, tid_t tid);
1011 int journal_start_commit(journal_t *journal, tid_t *tid);
1012 int journal_force_commit_nested(journal_t *journal);
1013 int log_wait_commit(journal_t *journal, tid_t tid);
1014 int log_do_checkpoint(journal_t *journal);
1016 void __log_wait_for_space(journal_t *journal);
1017 extern void __journal_drop_transaction(journal_t *, transaction_t *);
1018 extern int cleanup_journal_tail(journal_t *);
1020 /* Debugging code only: */
1022 #define jbd_ENOSYS() \
1024 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1025 current->state = TASK_UNINTERRUPTIBLE; \
1032 * Simple test wrapper function to test the JFS_ABORT state flag. This
1033 * bit, when set, indicates that we have had a fatal error somewhere,
1034 * either inside the journaling layer or indicated to us by the client
1035 * (eg. ext3), and that we and should not commit any further
1039 static inline int is_journal_aborted(journal_t *journal)
1041 return journal->j_flags & JFS_ABORT;
1044 static inline int is_handle_aborted(handle_t *handle)
1046 if (handle->h_aborted)
1048 return is_journal_aborted(handle->h_transaction->t_journal);
1051 static inline void journal_abort_handle(handle_t *handle)
1053 handle->h_aborted = 1;
1056 #endif /* __KERNEL__ */
1058 /* Comparison functions for transaction IDs: perform comparisons using
1059 * modulo arithmetic so that they work over sequence number wraps. */
1061 static inline int tid_gt(tid_t x, tid_t y)
1063 int difference = (x - y);
1064 return (difference > 0);
1067 static inline int tid_geq(tid_t x, tid_t y)
1069 int difference = (x - y);
1070 return (difference >= 0);
1073 extern int journal_blocks_per_page(struct inode *inode);
1076 * Return the minimum number of blocks which must be free in the journal
1077 * before a new transaction may be started. Must be called under j_state_lock.
1079 static inline int jbd_space_needed(journal_t *journal)
1081 int nblocks = journal->j_max_transaction_buffers;
1082 if (journal->j_committing_transaction)
1083 nblocks += journal->j_committing_transaction->
1084 t_outstanding_credits;
1089 * Definitions which augment the buffer_head layer
1092 /* journaling buffer types */
1093 #define BJ_None 0 /* Not journaled */
1094 #define BJ_SyncData 1 /* Normal data: flush before commit */
1095 #define BJ_Metadata 2 /* Normal journaled metadata */
1096 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1097 #define BJ_IO 4 /* Buffer is for temporary IO use */
1098 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1099 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1100 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1101 #define BJ_Locked 8 /* Locked for I/O during commit */
1104 extern int jbd_blocks_per_page(struct inode *inode);
1109 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
1111 #define assert_spin_locked(lock) do {} while(0)
1114 #define buffer_trace_init(bh) do {} while (0)
1115 #define print_buffer_fields(bh) do {} while (0)
1116 #define print_buffer_trace(bh) do {} while (0)
1117 #define BUFFER_TRACE(bh, info) do {} while (0)
1118 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1119 #define JBUFFER_TRACE(jh, info) do {} while (0)
1121 #endif /* __KERNEL__ */
1123 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
1126 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
1130 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
1132 #define J_ASSERT(expr) do {} while (0)
1133 #define J_ASSERT_BH(bh, expr) do {} while (0)
1134 #define buffer_jbd(bh) 0
1135 #define journal_buffer_journal_lru(bh) 0
1137 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
1138 #endif /* _LINUX_JBD_H */