[JFFS2] Correct parameter names of jffs2_compress() in comments
[linux-2.6/mini2440.git] / include / linux / jbd2.h
blob3dd2090070989863af4e87f9cc25b21900578bd9
1 /*
2 * linux/include/linux/jbd2.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.
16 #ifndef _LINUX_JBD2_H
17 #define _LINUX_JBD2_H
19 /* Allow this file to be included directly into e2fsprogs */
20 #ifndef __KERNEL__
21 #include "jfs_compat.h"
22 #define JBD2_DEBUG
23 #define jfs_debug jbd_debug
24 #else
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 #endif
35 #define journal_oom_retry 1
38 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
39 * certain classes of error which can occur due to failed IOs. Under
40 * normal use we want ext4 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 JBD2_PARANOID_IOFAIL
47 * The default maximum commit age, in seconds.
49 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
51 #ifdef CONFIG_JBD2_DEBUG
53 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
54 * consistency checks. By default we don't do this unless
55 * CONFIG_JBD2_DEBUG is on.
57 #define JBD2_EXPENSIVE_CHECKING
58 extern u8 jbd2_journal_enable_debug;
60 #define jbd_debug(n, f, a...) \
61 do { \
62 if ((n) <= jbd2_journal_enable_debug) { \
63 printk (KERN_DEBUG "(%s, %d): %s: ", \
64 __FILE__, __LINE__, __FUNCTION__); \
65 printk (f, ## a); \
66 } \
67 } while (0)
68 #else
69 #define jbd_debug(f, a...) /**/
70 #endif
72 static inline void *jbd2_alloc(size_t size, gfp_t flags)
74 return (void *)__get_free_pages(flags, get_order(size));
77 static inline void jbd2_free(void *ptr, size_t size)
79 free_pages((unsigned long)ptr, get_order(size));
82 #define JBD2_MIN_JOURNAL_BLOCKS 1024
84 #ifdef __KERNEL__
86 /**
87 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
89 * All filesystem modifications made by the process go
90 * through this handle. Recursive operations (such as quota operations)
91 * are gathered into a single update.
93 * The buffer credits field is used to account for journaled buffers
94 * being modified by the running process. To ensure that there is
95 * enough log space for all outstanding operations, we need to limit the
96 * number of outstanding buffers possible at any time. When the
97 * operation completes, any buffer credits not used are credited back to
98 * the transaction, so that at all times we know how many buffers the
99 * outstanding updates on a transaction might possibly touch.
101 * This is an opaque datatype.
103 typedef struct handle_s handle_t; /* Atomic operation type */
107 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
109 * journal_t is linked to from the fs superblock structure.
111 * We use the journal_t to keep track of all outstanding transaction
112 * activity on the filesystem, and to manage the state of the log
113 * writing process.
115 * This is an opaque datatype.
117 typedef struct journal_s journal_t; /* Journal control structure */
118 #endif
121 * Internal structures used by the logging mechanism:
124 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
127 * On-disk structures
131 * Descriptor block types:
134 #define JBD2_DESCRIPTOR_BLOCK 1
135 #define JBD2_COMMIT_BLOCK 2
136 #define JBD2_SUPERBLOCK_V1 3
137 #define JBD2_SUPERBLOCK_V2 4
138 #define JBD2_REVOKE_BLOCK 5
141 * Standard header for all descriptor blocks:
143 typedef struct journal_header_s
145 __be32 h_magic;
146 __be32 h_blocktype;
147 __be32 h_sequence;
148 } journal_header_t;
151 * Checksum types.
153 #define JBD2_CRC32_CHKSUM 1
154 #define JBD2_MD5_CHKSUM 2
155 #define JBD2_SHA1_CHKSUM 3
157 #define JBD2_CRC32_CHKSUM_SIZE 4
159 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
161 * Commit block header for storing transactional checksums:
163 struct commit_header {
164 __be32 h_magic;
165 __be32 h_blocktype;
166 __be32 h_sequence;
167 unsigned char h_chksum_type;
168 unsigned char h_chksum_size;
169 unsigned char h_padding[2];
170 __be32 h_chksum[JBD2_CHECKSUM_BYTES];
171 __be64 h_commit_sec;
172 __be32 h_commit_nsec;
176 * The block tag: used to describe a single buffer in the journal.
177 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
178 * raw struct shouldn't be used for pointer math or sizeof() - use
179 * journal_tag_bytes(journal) instead to compute this.
181 typedef struct journal_block_tag_s
183 __be32 t_blocknr; /* The on-disk block number */
184 __be32 t_flags; /* See below */
185 __be32 t_blocknr_high; /* most-significant high 32bits. */
186 } journal_block_tag_t;
188 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high))
189 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t))
192 * The revoke descriptor: used on disk to describe a series of blocks to
193 * be revoked from the log
195 typedef struct jbd2_journal_revoke_header_s
197 journal_header_t r_header;
198 __be32 r_count; /* Count of bytes used in the block */
199 } jbd2_journal_revoke_header_t;
202 /* Definitions for the journal tag flags word: */
203 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */
204 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */
205 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */
206 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
210 * The journal superblock. All fields are in big-endian byte order.
212 typedef struct journal_superblock_s
214 /* 0x0000 */
215 journal_header_t s_header;
217 /* 0x000C */
218 /* Static information describing the journal */
219 __be32 s_blocksize; /* journal device blocksize */
220 __be32 s_maxlen; /* total blocks in journal file */
221 __be32 s_first; /* first block of log information */
223 /* 0x0018 */
224 /* Dynamic information describing the current state of the log */
225 __be32 s_sequence; /* first commit ID expected in log */
226 __be32 s_start; /* blocknr of start of log */
228 /* 0x0020 */
229 /* Error value, as set by jbd2_journal_abort(). */
230 __be32 s_errno;
232 /* 0x0024 */
233 /* Remaining fields are only valid in a version-2 superblock */
234 __be32 s_feature_compat; /* compatible feature set */
235 __be32 s_feature_incompat; /* incompatible feature set */
236 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
237 /* 0x0030 */
238 __u8 s_uuid[16]; /* 128-bit uuid for journal */
240 /* 0x0040 */
241 __be32 s_nr_users; /* Nr of filesystems sharing log */
243 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
245 /* 0x0048 */
246 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
247 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
249 /* 0x0050 */
250 __u32 s_padding[44];
252 /* 0x0100 */
253 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
254 /* 0x0400 */
255 } journal_superblock_t;
257 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \
258 ((j)->j_format_version >= 2 && \
259 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
260 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \
261 ((j)->j_format_version >= 2 && \
262 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
263 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \
264 ((j)->j_format_version >= 2 && \
265 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
267 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001
269 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001
270 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002
271 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
273 /* Features known to this kernel version: */
274 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM
275 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0
276 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \
277 JBD2_FEATURE_INCOMPAT_64BIT | \
278 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)
280 #ifdef __KERNEL__
282 #include <linux/fs.h>
283 #include <linux/sched.h>
285 #define J_ASSERT(assert) BUG_ON(!(assert))
287 #if defined(CONFIG_BUFFER_DEBUG)
288 void buffer_assertion_failure(struct buffer_head *bh);
289 #define J_ASSERT_BH(bh, expr) \
290 do { \
291 if (!(expr)) \
292 buffer_assertion_failure(bh); \
293 J_ASSERT(expr); \
294 } while (0)
295 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
296 #else
297 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
298 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
299 #endif
301 #if defined(JBD2_PARANOID_IOFAIL)
302 #define J_EXPECT(expr, why...) J_ASSERT(expr)
303 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
304 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
305 #else
306 #define __journal_expect(expr, why...) \
307 ({ \
308 int val = (expr); \
309 if (!val) { \
310 printk(KERN_ERR \
311 "EXT3-fs unexpected failure: %s;\n",# expr); \
312 printk(KERN_ERR why "\n"); \
314 val; \
316 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
317 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
318 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
319 #endif
321 enum jbd_state_bits {
322 BH_JBD /* Has an attached ext3 journal_head */
323 = BH_PrivateStart,
324 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
325 BH_Freed, /* Has been freed (truncated) */
326 BH_Revoked, /* Has been revoked from the log */
327 BH_RevokeValid, /* Revoked flag is valid */
328 BH_JBDDirty, /* Is dirty but journaled */
329 BH_State, /* Pins most journal_head state */
330 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
331 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
334 BUFFER_FNS(JBD, jbd)
335 BUFFER_FNS(JWrite, jwrite)
336 BUFFER_FNS(JBDDirty, jbddirty)
337 TAS_BUFFER_FNS(JBDDirty, jbddirty)
338 BUFFER_FNS(Revoked, revoked)
339 TAS_BUFFER_FNS(Revoked, revoked)
340 BUFFER_FNS(RevokeValid, revokevalid)
341 TAS_BUFFER_FNS(RevokeValid, revokevalid)
342 BUFFER_FNS(Freed, freed)
344 static inline struct buffer_head *jh2bh(struct journal_head *jh)
346 return jh->b_bh;
349 static inline struct journal_head *bh2jh(struct buffer_head *bh)
351 return bh->b_private;
354 static inline void jbd_lock_bh_state(struct buffer_head *bh)
356 bit_spin_lock(BH_State, &bh->b_state);
359 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
361 return bit_spin_trylock(BH_State, &bh->b_state);
364 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
366 return bit_spin_is_locked(BH_State, &bh->b_state);
369 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
371 bit_spin_unlock(BH_State, &bh->b_state);
374 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
376 bit_spin_lock(BH_JournalHead, &bh->b_state);
379 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
381 bit_spin_unlock(BH_JournalHead, &bh->b_state);
384 /* Flags in jbd_inode->i_flags */
385 #define __JI_COMMIT_RUNNING 0
386 /* Commit of the inode data in progress. We use this flag to protect us from
387 * concurrent deletion of inode. We cannot use reference to inode for this
388 * since we cannot afford doing last iput() on behalf of kjournald
390 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
393 * struct jbd_inode is the structure linking inodes in ordered mode
394 * present in a transaction so that we can sync them during commit.
396 struct jbd2_inode {
397 /* Which transaction does this inode belong to? Either the running
398 * transaction or the committing one. [j_list_lock] */
399 transaction_t *i_transaction;
401 /* Pointer to the running transaction modifying inode's data in case
402 * there is already a committing transaction touching it. [j_list_lock] */
403 transaction_t *i_next_transaction;
405 /* List of inodes in the i_transaction [j_list_lock] */
406 struct list_head i_list;
408 /* VFS inode this inode belongs to [constant during the lifetime
409 * of the structure] */
410 struct inode *i_vfs_inode;
412 /* Flags of inode [j_list_lock] */
413 unsigned int i_flags;
416 struct jbd2_revoke_table_s;
419 * struct handle_s - The handle_s type is the concrete type associated with
420 * handle_t.
421 * @h_transaction: Which compound transaction is this update a part of?
422 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
423 * @h_ref: Reference count on this handle
424 * @h_err: Field for caller's use to track errors through large fs operations
425 * @h_sync: flag for sync-on-close
426 * @h_jdata: flag to force data journaling
427 * @h_aborted: flag indicating fatal error on handle
430 /* Docbook can't yet cope with the bit fields, but will leave the documentation
431 * in so it can be fixed later.
434 struct handle_s
436 /* Which compound transaction is this update a part of? */
437 transaction_t *h_transaction;
439 /* Number of remaining buffers we are allowed to dirty: */
440 int h_buffer_credits;
442 /* Reference count on this handle */
443 int h_ref;
445 /* Field for caller's use to track errors through large fs */
446 /* operations */
447 int h_err;
449 /* Flags [no locking] */
450 unsigned int h_sync: 1; /* sync-on-close */
451 unsigned int h_jdata: 1; /* force data journaling */
452 unsigned int h_aborted: 1; /* fatal error on handle */
454 #ifdef CONFIG_DEBUG_LOCK_ALLOC
455 struct lockdep_map h_lockdep_map;
456 #endif
461 * Some stats for checkpoint phase
463 struct transaction_chp_stats_s {
464 unsigned long cs_chp_time;
465 unsigned long cs_forced_to_close;
466 unsigned long cs_written;
467 unsigned long cs_dropped;
470 /* The transaction_t type is the guts of the journaling mechanism. It
471 * tracks a compound transaction through its various states:
473 * RUNNING: accepting new updates
474 * LOCKED: Updates still running but we don't accept new ones
475 * RUNDOWN: Updates are tidying up but have finished requesting
476 * new buffers to modify (state not used for now)
477 * FLUSH: All updates complete, but we are still writing to disk
478 * COMMIT: All data on disk, writing commit record
479 * FINISHED: We still have to keep the transaction for checkpointing.
481 * The transaction keeps track of all of the buffers modified by a
482 * running transaction, and all of the buffers committed but not yet
483 * flushed to home for finished transactions.
487 * Lock ranking:
489 * j_list_lock
490 * ->jbd_lock_bh_journal_head() (This is "innermost")
492 * j_state_lock
493 * ->jbd_lock_bh_state()
495 * jbd_lock_bh_state()
496 * ->j_list_lock
498 * j_state_lock
499 * ->t_handle_lock
501 * j_state_lock
502 * ->j_list_lock (journal_unmap_buffer)
506 struct transaction_s
508 /* Pointer to the journal for this transaction. [no locking] */
509 journal_t *t_journal;
511 /* Sequence number for this transaction [no locking] */
512 tid_t t_tid;
515 * Transaction's current state
516 * [no locking - only kjournald2 alters this]
517 * [j_list_lock] guards transition of a transaction into T_FINISHED
518 * state and subsequent call of __jbd2_journal_drop_transaction()
519 * FIXME: needs barriers
520 * KLUDGE: [use j_state_lock]
522 enum {
523 T_RUNNING,
524 T_LOCKED,
525 T_RUNDOWN,
526 T_FLUSH,
527 T_COMMIT,
528 T_FINISHED
529 } t_state;
532 * Where in the log does this transaction's commit start? [no locking]
534 unsigned long t_log_start;
536 /* Number of buffers on the t_buffers list [j_list_lock] */
537 int t_nr_buffers;
540 * Doubly-linked circular list of all buffers reserved but not yet
541 * modified by this transaction [j_list_lock]
543 struct journal_head *t_reserved_list;
546 * Doubly-linked circular list of all metadata buffers owned by this
547 * transaction [j_list_lock]
549 struct journal_head *t_buffers;
552 * Doubly-linked circular list of all forget buffers (superseded
553 * buffers which we can un-checkpoint once this transaction commits)
554 * [j_list_lock]
556 struct journal_head *t_forget;
559 * Doubly-linked circular list of all buffers still to be flushed before
560 * this transaction can be checkpointed. [j_list_lock]
562 struct journal_head *t_checkpoint_list;
565 * Doubly-linked circular list of all buffers submitted for IO while
566 * checkpointing. [j_list_lock]
568 struct journal_head *t_checkpoint_io_list;
571 * Doubly-linked circular list of temporary buffers currently undergoing
572 * IO in the log [j_list_lock]
574 struct journal_head *t_iobuf_list;
577 * Doubly-linked circular list of metadata buffers being shadowed by log
578 * IO. The IO buffers on the iobuf list and the shadow buffers on this
579 * list match each other one for one at all times. [j_list_lock]
581 struct journal_head *t_shadow_list;
584 * Doubly-linked circular list of control buffers being written to the
585 * log. [j_list_lock]
587 struct journal_head *t_log_list;
590 * List of inodes whose data we've modified in data=ordered mode.
591 * [j_list_lock]
593 struct list_head t_inode_list;
596 * Protects info related to handles
598 spinlock_t t_handle_lock;
601 * Longest time some handle had to wait for running transaction
603 unsigned long t_max_wait;
606 * When transaction started
608 unsigned long t_start;
611 * Checkpointing stats [j_checkpoint_sem]
613 struct transaction_chp_stats_s t_chp_stats;
616 * Number of outstanding updates running on this transaction
617 * [t_handle_lock]
619 int t_updates;
622 * Number of buffers reserved for use by all handles in this transaction
623 * handle but not yet modified. [t_handle_lock]
625 int t_outstanding_credits;
628 * Forward and backward links for the circular list of all transactions
629 * awaiting checkpoint. [j_list_lock]
631 transaction_t *t_cpnext, *t_cpprev;
634 * When will the transaction expire (become due for commit), in jiffies?
635 * [no locking]
637 unsigned long t_expires;
640 * How many handles used this transaction? [t_handle_lock]
642 int t_handle_count;
646 struct transaction_run_stats_s {
647 unsigned long rs_wait;
648 unsigned long rs_running;
649 unsigned long rs_locked;
650 unsigned long rs_flushing;
651 unsigned long rs_logging;
653 unsigned long rs_handle_count;
654 unsigned long rs_blocks;
655 unsigned long rs_blocks_logged;
658 struct transaction_stats_s {
659 int ts_type;
660 unsigned long ts_tid;
661 union {
662 struct transaction_run_stats_s run;
663 struct transaction_chp_stats_s chp;
664 } u;
667 #define JBD2_STATS_RUN 1
668 #define JBD2_STATS_CHECKPOINT 2
670 static inline unsigned long
671 jbd2_time_diff(unsigned long start, unsigned long end)
673 if (end >= start)
674 return end - start;
676 return end + (MAX_JIFFY_OFFSET - start);
680 * struct journal_s - The journal_s type is the concrete type associated with
681 * journal_t.
682 * @j_flags: General journaling state flags
683 * @j_errno: Is there an outstanding uncleared error on the journal (from a
684 * prior abort)?
685 * @j_sb_buffer: First part of superblock buffer
686 * @j_superblock: Second part of superblock buffer
687 * @j_format_version: Version of the superblock format
688 * @j_state_lock: Protect the various scalars in the journal
689 * @j_barrier_count: Number of processes waiting to create a barrier lock
690 * @j_barrier: The barrier lock itself
691 * @j_running_transaction: The current running transaction..
692 * @j_committing_transaction: the transaction we are pushing to disk
693 * @j_checkpoint_transactions: a linked circular list of all transactions
694 * waiting for checkpointing
695 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
696 * to start committing, or for a barrier lock to be released
697 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
698 * @j_wait_done_commit: Wait queue for waiting for commit to complete
699 * @j_wait_checkpoint: Wait queue to trigger checkpointing
700 * @j_wait_commit: Wait queue to trigger commit
701 * @j_wait_updates: Wait queue to wait for updates to complete
702 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
703 * @j_head: Journal head - identifies the first unused block in the journal
704 * @j_tail: Journal tail - identifies the oldest still-used block in the
705 * journal.
706 * @j_free: Journal free - how many free blocks are there in the journal?
707 * @j_first: The block number of the first usable block
708 * @j_last: The block number one beyond the last usable block
709 * @j_dev: Device where we store the journal
710 * @j_blocksize: blocksize for the location where we store the journal.
711 * @j_blk_offset: starting block offset for into the device where we store the
712 * journal
713 * @j_fs_dev: Device which holds the client fs. For internal journal this will
714 * be equal to j_dev
715 * @j_maxlen: Total maximum capacity of the journal region on disk.
716 * @j_list_lock: Protects the buffer lists and internal buffer state.
717 * @j_inode: Optional inode where we store the journal. If present, all journal
718 * block numbers are mapped into this inode via bmap().
719 * @j_tail_sequence: Sequence number of the oldest transaction in the log
720 * @j_transaction_sequence: Sequence number of the next transaction to grant
721 * @j_commit_sequence: Sequence number of the most recently committed
722 * transaction
723 * @j_commit_request: Sequence number of the most recent transaction wanting
724 * commit
725 * @j_uuid: Uuid of client object.
726 * @j_task: Pointer to the current commit thread for this journal
727 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
728 * single compound commit transaction
729 * @j_commit_interval: What is the maximum transaction lifetime before we begin
730 * a commit?
731 * @j_commit_timer: The timer used to wakeup the commit thread
732 * @j_revoke_lock: Protect the revoke table
733 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
734 * current transaction.
735 * @j_revoke_table: alternate revoke tables for j_revoke
736 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction
737 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
738 * number that will fit in j_blocksize
739 * @j_last_sync_writer: most recent pid which did a synchronous write
740 * @j_history: Buffer storing the transactions statistics history
741 * @j_history_max: Maximum number of transactions in the statistics history
742 * @j_history_cur: Current number of transactions in the statistics history
743 * @j_history_lock: Protect the transactions statistics history
744 * @j_proc_entry: procfs entry for the jbd statistics directory
745 * @j_stats: Overall statistics
746 * @j_private: An opaque pointer to fs-private information.
749 struct journal_s
751 /* General journaling state flags [j_state_lock] */
752 unsigned long j_flags;
755 * Is there an outstanding uncleared error on the journal (from a prior
756 * abort)? [j_state_lock]
758 int j_errno;
760 /* The superblock buffer */
761 struct buffer_head *j_sb_buffer;
762 journal_superblock_t *j_superblock;
764 /* Version of the superblock format */
765 int j_format_version;
768 * Protect the various scalars in the journal
770 spinlock_t j_state_lock;
773 * Number of processes waiting to create a barrier lock [j_state_lock]
775 int j_barrier_count;
777 /* The barrier lock itself */
778 struct mutex j_barrier;
781 * Transactions: The current running transaction...
782 * [j_state_lock] [caller holding open handle]
784 transaction_t *j_running_transaction;
787 * the transaction we are pushing to disk
788 * [j_state_lock] [caller holding open handle]
790 transaction_t *j_committing_transaction;
793 * ... and a linked circular list of all transactions waiting for
794 * checkpointing. [j_list_lock]
796 transaction_t *j_checkpoint_transactions;
799 * Wait queue for waiting for a locked transaction to start committing,
800 * or for a barrier lock to be released
802 wait_queue_head_t j_wait_transaction_locked;
804 /* Wait queue for waiting for checkpointing to complete */
805 wait_queue_head_t j_wait_logspace;
807 /* Wait queue for waiting for commit to complete */
808 wait_queue_head_t j_wait_done_commit;
810 /* Wait queue to trigger checkpointing */
811 wait_queue_head_t j_wait_checkpoint;
813 /* Wait queue to trigger commit */
814 wait_queue_head_t j_wait_commit;
816 /* Wait queue to wait for updates to complete */
817 wait_queue_head_t j_wait_updates;
819 /* Semaphore for locking against concurrent checkpoints */
820 struct mutex j_checkpoint_mutex;
823 * Journal head: identifies the first unused block in the journal.
824 * [j_state_lock]
826 unsigned long j_head;
829 * Journal tail: identifies the oldest still-used block in the journal.
830 * [j_state_lock]
832 unsigned long j_tail;
835 * Journal free: how many free blocks are there in the journal?
836 * [j_state_lock]
838 unsigned long j_free;
841 * Journal start and end: the block numbers of the first usable block
842 * and one beyond the last usable block in the journal. [j_state_lock]
844 unsigned long j_first;
845 unsigned long j_last;
848 * Device, blocksize and starting block offset for the location where we
849 * store the journal.
851 struct block_device *j_dev;
852 int j_blocksize;
853 unsigned long long j_blk_offset;
856 * Device which holds the client fs. For internal journal this will be
857 * equal to j_dev.
859 struct block_device *j_fs_dev;
861 /* Total maximum capacity of the journal region on disk. */
862 unsigned int j_maxlen;
865 * Protects the buffer lists and internal buffer state.
867 spinlock_t j_list_lock;
869 /* Optional inode where we store the journal. If present, all */
870 /* journal block numbers are mapped into this inode via */
871 /* bmap(). */
872 struct inode *j_inode;
875 * Sequence number of the oldest transaction in the log [j_state_lock]
877 tid_t j_tail_sequence;
880 * Sequence number of the next transaction to grant [j_state_lock]
882 tid_t j_transaction_sequence;
885 * Sequence number of the most recently committed transaction
886 * [j_state_lock].
888 tid_t j_commit_sequence;
891 * Sequence number of the most recent transaction wanting commit
892 * [j_state_lock]
894 tid_t j_commit_request;
897 * Journal uuid: identifies the object (filesystem, LVM volume etc)
898 * backed by this journal. This will eventually be replaced by an array
899 * of uuids, allowing us to index multiple devices within a single
900 * journal and to perform atomic updates across them.
902 __u8 j_uuid[16];
904 /* Pointer to the current commit thread for this journal */
905 struct task_struct *j_task;
908 * Maximum number of metadata buffers to allow in a single compound
909 * commit transaction
911 int j_max_transaction_buffers;
914 * What is the maximum transaction lifetime before we begin a commit?
916 unsigned long j_commit_interval;
918 /* The timer used to wakeup the commit thread: */
919 struct timer_list j_commit_timer;
922 * The revoke table: maintains the list of revoked blocks in the
923 * current transaction. [j_revoke_lock]
925 spinlock_t j_revoke_lock;
926 struct jbd2_revoke_table_s *j_revoke;
927 struct jbd2_revoke_table_s *j_revoke_table[2];
930 * array of bhs for jbd2_journal_commit_transaction
932 struct buffer_head **j_wbuf;
933 int j_wbufsize;
935 pid_t j_last_sync_writer;
938 * Journal statistics
940 struct transaction_stats_s *j_history;
941 int j_history_max;
942 int j_history_cur;
944 * Protect the transactions statistics history
946 spinlock_t j_history_lock;
947 struct proc_dir_entry *j_proc_entry;
948 struct transaction_stats_s j_stats;
950 /* Failed journal commit ID */
951 unsigned int j_failed_commit;
954 * An opaque pointer to fs-private information. ext3 puts its
955 * superblock pointer here
957 void *j_private;
961 * Journal flag definitions
963 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
964 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
965 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
966 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
967 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
968 #define JBD2_BARRIER 0x020 /* Use IDE barriers */
971 * Function declarations for the journaling transaction and buffer
972 * management
975 /* Filing buffers */
976 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
977 extern void __jbd2_journal_unfile_buffer(struct journal_head *);
978 extern void __jbd2_journal_refile_buffer(struct journal_head *);
979 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
980 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
981 extern void __journal_free_buffer(struct journal_head *bh);
982 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
983 extern void __journal_clean_data_list(transaction_t *transaction);
985 /* Log buffer allocation */
986 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *);
987 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
989 /* Commit management */
990 extern void jbd2_journal_commit_transaction(journal_t *);
992 /* Checkpoint list management */
993 int __jbd2_journal_clean_checkpoint_list(journal_t *journal);
994 int __jbd2_journal_remove_checkpoint(struct journal_head *);
995 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
997 /* Buffer IO */
998 extern int
999 jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1000 struct journal_head *jh_in,
1001 struct journal_head **jh_out,
1002 unsigned long long blocknr);
1004 /* Transaction locking */
1005 extern void __wait_on_journal (journal_t *);
1008 * Journal locking.
1010 * We need to lock the journal during transaction state changes so that nobody
1011 * ever tries to take a handle on the running transaction while we are in the
1012 * middle of moving it to the commit phase. j_state_lock does this.
1014 * Note that the locking is completely interrupt unsafe. We never touch
1015 * journal structures from interrupts.
1018 static inline handle_t *journal_current_handle(void)
1020 return current->journal_info;
1023 /* The journaling code user interface:
1025 * Create and destroy handles
1026 * Register buffer modifications against the current transaction.
1029 extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1030 extern int jbd2_journal_restart (handle_t *, int nblocks);
1031 extern int jbd2_journal_extend (handle_t *, int nblocks);
1032 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1033 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1034 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1035 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1036 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *);
1037 extern int jbd2_journal_forget (handle_t *, struct buffer_head *);
1038 extern void journal_sync_buffer (struct buffer_head *);
1039 extern void jbd2_journal_invalidatepage(journal_t *,
1040 struct page *, unsigned long);
1041 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
1042 extern int jbd2_journal_stop(handle_t *);
1043 extern int jbd2_journal_flush (journal_t *);
1044 extern void jbd2_journal_lock_updates (journal_t *);
1045 extern void jbd2_journal_unlock_updates (journal_t *);
1047 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1048 struct block_device *fs_dev,
1049 unsigned long long start, int len, int bsize);
1050 extern journal_t * jbd2_journal_init_inode (struct inode *);
1051 extern int jbd2_journal_update_format (journal_t *);
1052 extern int jbd2_journal_check_used_features
1053 (journal_t *, unsigned long, unsigned long, unsigned long);
1054 extern int jbd2_journal_check_available_features
1055 (journal_t *, unsigned long, unsigned long, unsigned long);
1056 extern int jbd2_journal_set_features
1057 (journal_t *, unsigned long, unsigned long, unsigned long);
1058 extern void jbd2_journal_clear_features
1059 (journal_t *, unsigned long, unsigned long, unsigned long);
1060 extern int jbd2_journal_create (journal_t *);
1061 extern int jbd2_journal_load (journal_t *journal);
1062 extern void jbd2_journal_destroy (journal_t *);
1063 extern int jbd2_journal_recover (journal_t *journal);
1064 extern int jbd2_journal_wipe (journal_t *, int);
1065 extern int jbd2_journal_skip_recovery (journal_t *);
1066 extern void jbd2_journal_update_superblock (journal_t *, int);
1067 extern void __jbd2_journal_abort_hard (journal_t *);
1068 extern void jbd2_journal_abort (journal_t *, int);
1069 extern int jbd2_journal_errno (journal_t *);
1070 extern void jbd2_journal_ack_err (journal_t *);
1071 extern int jbd2_journal_clear_err (journal_t *);
1072 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1073 extern int jbd2_journal_force_commit(journal_t *);
1074 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode);
1075 extern int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode, loff_t new_size);
1076 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1077 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1080 * journal_head management
1082 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1083 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1084 void jbd2_journal_remove_journal_head(struct buffer_head *bh);
1085 void jbd2_journal_put_journal_head(struct journal_head *jh);
1088 * handle management
1090 extern struct kmem_cache *jbd2_handle_cache;
1092 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1094 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags);
1097 static inline void jbd2_free_handle(handle_t *handle)
1099 kmem_cache_free(jbd2_handle_cache, handle);
1102 /* Primary revoke support */
1103 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1104 extern int jbd2_journal_init_revoke(journal_t *, int);
1105 extern void jbd2_journal_destroy_revoke_caches(void);
1106 extern int jbd2_journal_init_revoke_caches(void);
1108 extern void jbd2_journal_destroy_revoke(journal_t *);
1109 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1110 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1111 extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *);
1113 /* Recovery revoke support */
1114 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1115 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1116 extern void jbd2_journal_clear_revoke(journal_t *);
1117 extern void jbd2_journal_switch_revoke_table(journal_t *journal);
1120 * The log thread user interface:
1122 * Request space in the current transaction, and force transaction commit
1123 * transitions on demand.
1126 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */
1127 int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1128 int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
1129 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1130 int jbd2_journal_force_commit_nested(journal_t *journal);
1131 int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1132 int jbd2_log_do_checkpoint(journal_t *journal);
1134 void __jbd2_log_wait_for_space(journal_t *journal);
1135 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1136 extern int jbd2_cleanup_journal_tail(journal_t *);
1138 /* Debugging code only: */
1140 #define jbd_ENOSYS() \
1141 do { \
1142 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1143 current->state = TASK_UNINTERRUPTIBLE; \
1144 schedule(); \
1145 } while (1)
1148 * is_journal_abort
1150 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1151 * bit, when set, indicates that we have had a fatal error somewhere,
1152 * either inside the journaling layer or indicated to us by the client
1153 * (eg. ext3), and that we and should not commit any further
1154 * transactions.
1157 static inline int is_journal_aborted(journal_t *journal)
1159 return journal->j_flags & JBD2_ABORT;
1162 static inline int is_handle_aborted(handle_t *handle)
1164 if (handle->h_aborted)
1165 return 1;
1166 return is_journal_aborted(handle->h_transaction->t_journal);
1169 static inline void jbd2_journal_abort_handle(handle_t *handle)
1171 handle->h_aborted = 1;
1174 #endif /* __KERNEL__ */
1176 /* Comparison functions for transaction IDs: perform comparisons using
1177 * modulo arithmetic so that they work over sequence number wraps. */
1179 static inline int tid_gt(tid_t x, tid_t y)
1181 int difference = (x - y);
1182 return (difference > 0);
1185 static inline int tid_geq(tid_t x, tid_t y)
1187 int difference = (x - y);
1188 return (difference >= 0);
1191 extern int jbd2_journal_blocks_per_page(struct inode *inode);
1192 extern size_t journal_tag_bytes(journal_t *journal);
1195 * Return the minimum number of blocks which must be free in the journal
1196 * before a new transaction may be started. Must be called under j_state_lock.
1198 static inline int jbd_space_needed(journal_t *journal)
1200 int nblocks = journal->j_max_transaction_buffers;
1201 if (journal->j_committing_transaction)
1202 nblocks += journal->j_committing_transaction->
1203 t_outstanding_credits;
1204 return nblocks;
1208 * Definitions which augment the buffer_head layer
1211 /* journaling buffer types */
1212 #define BJ_None 0 /* Not journaled */
1213 #define BJ_Metadata 1 /* Normal journaled metadata */
1214 #define BJ_Forget 2 /* Buffer superseded by this transaction */
1215 #define BJ_IO 3 /* Buffer is for temporary IO use */
1216 #define BJ_Shadow 4 /* Buffer contents being shadowed to the log */
1217 #define BJ_LogCtl 5 /* Buffer contains log descriptors */
1218 #define BJ_Reserved 6 /* Buffer is reserved for access by journal */
1219 #define BJ_Types 7
1221 extern int jbd_blocks_per_page(struct inode *inode);
1223 #ifdef __KERNEL__
1225 #define buffer_trace_init(bh) do {} while (0)
1226 #define print_buffer_fields(bh) do {} while (0)
1227 #define print_buffer_trace(bh) do {} while (0)
1228 #define BUFFER_TRACE(bh, info) do {} while (0)
1229 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1230 #define JBUFFER_TRACE(jh, info) do {} while (0)
1232 #endif /* __KERNEL__ */
1234 #endif /* _LINUX_JBD2_H */