1 /*
2 * linux/include/linux/jbd.h
3 *
4 * Written by Stephen C. Tweedie <sct@redhat.com>
5 *
6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
7 *
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.
11 *
12 * Definitions for transaction data structures for the buffer cache
13 * filesystem journaling support.
14 */
15
16 #ifndef _LINUX_JBD_H
17 #define _LINUX_JBD_H
18
19 /* Allow this file to be included directly into e2fsprogs */
20 #ifndef __KERNEL__
21 #include "jfs_compat.h"
22 #define JFS_DEBUG
23 #define jfs_debug jbd_debug
24 #else
25
26 #include <linux/module.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>
34
35 #include <asm/semaphore.h>
36
37 #define journal_oom_retry 1
38
39 #define jbdlock_t FAST_MUTEX
40
jbd_lock_init(jbdlock_t * lock)41 static inline void jbd_lock_init(jbdlock_t *lock)
42 {
43 ExInitializeFastMutex(lock);
44 }
45
jbd_lock(jbdlock_t * lock)46 static inline void jbd_lock(jbdlock_t *lock)
47 {
48 ExAcquireFastMutex(lock);
49 }
50
jbd_unlock(jbdlock_t * lock)51 static inline void jbd_unlock(jbdlock_t *lock)
52 {
53 ExReleaseFastMutex(lock);
54 }
55
assert_jbd_locked(jbdlock_t * lock)56 static inline int assert_jbd_locked(jbdlock_t *lock)
57 {
58 int rc = 1;
59
60 if (ExTryToAcquireFastMutex(lock)) {
61 ExReleaseFastMutex(lock);
62 rc = 0;
63 }
64
65 return rc;
66 }
67
68
69 /*
70 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
71 * certain classes of error which can occur due to failed IOs. Under
72 * normal use we want ext3 to continue after such errors, because
73 * hardware _can_ fail, but for debugging purposes when running tests on
74 * known-good hardware we may want to trap these errors.
75 */
76 #undef JBD_PARANOID_IOFAIL
77
78 /*
79 * The default maximum commit age, in seconds.
80 */
81 #define JBD_DEFAULT_MAX_COMMIT_AGE 5
82
83 #ifdef CONFIG_JBD_DEBUG
84 /*
85 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
86 * consistency checks. By default we don't do this unless
87 * CONFIG_JBD_DEBUG is on.
88 */
89 #define JBD_EXPENSIVE_CHECKING
90 extern u8 journal_enable_debug;
91
92 #define jbd_debug(n, f, a...) \
93 do { \
94 if ((n) <= journal_enable_debug) { \
95 printk (KERN_DEBUG "(%s, %d): %s: ", \
96 __FILE__, __LINE__, __FUNCTION__); \
97 printk (f, ## a); \
98 } \
99 } while (0)
100 #else
101 #define jbd_debug
102 #endif
103
jbd_alloc(size_t size,gfp_t flags)104 static inline void *jbd_alloc(size_t size, gfp_t flags)
105 {
106 return kmalloc(size, flags);
107 /*__get_free_pages(flags, get_order(size));*/
108 }
109
jbd_free(void * ptr,size_t size)110 static inline void jbd_free(void *ptr, size_t size)
111 {
112 if (ptr) {
113 kfree(ptr);
114 }
115 /* free_pages((unsigned long)ptr, get_order(size)); */
116 };
117
118 #define JFS_MIN_JOURNAL_BLOCKS 1024
119
120
121 /**
122 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
123 *
124 * All filesystem modifications made by the process go
125 * through this handle. Recursive operations (such as quota operations)
126 * are gathered into a single update.
127 *
128 * The buffer credits field is used to account for journaled buffers
129 * being modified by the running process. To ensure that there is
130 * enough log space for all outstanding operations, we need to limit the
131 * number of outstanding buffers possible at any time. When the
132 * operation completes, any buffer credits not used are credited back to
133 * the transaction, so that at all times we know how many buffers the
134 * outstanding updates on a transaction might possibly touch.
135 *
136 * This is an opaque datatype.
137 **/
138 typedef struct handle_s handle_t; /* Atomic operation type */
139
140
141 /**
142 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
143 *
144 * journal_t is linked to from the fs superblock structure.
145 *
146 * We use the journal_t to keep track of all outstanding transaction
147 * activity on the filesystem, and to manage the state of the log
148 * writing process.
149 *
150 * This is an opaque datatype.
151 **/
152 typedef struct journal_s journal_t; /* Journal control structure */
153 #endif
154
155 /*
156 * Internal structures used by the logging mechanism:
157 */
158
159 #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
160
161 /*
162 * On-disk structures
163 */
164
165 /*
166 * Descriptor block types:
167 */
168
169 #define JFS_DESCRIPTOR_BLOCK 1
170 #define JFS_COMMIT_BLOCK 2
171 #define JFS_SUPERBLOCK_V1 3
172 #define JFS_SUPERBLOCK_V2 4
173 #define JFS_REVOKE_BLOCK 5
174
175 /*
176 * Standard header for all descriptor blocks:
177 */
178 typedef struct journal_header_s
179 {
180 __be32 h_magic;
181 __be32 h_blocktype;
182 __be32 h_sequence;
183 } journal_header_t;
184
185
186 /*
187 * The block tag: used to describe a single buffer in the journal
188 */
189 typedef struct journal_block_tag_s
190 {
191 __be32 t_blocknr; /* The on-disk block number */
192 __be32 t_flags; /* See below */
193 } journal_block_tag_t;
194
195 /*
196 * The revoke descriptor: used on disk to describe a series of blocks to
197 * be revoked from the log
198 */
199 typedef struct journal_revoke_header_s
200 {
201 journal_header_t r_header;
202 __be32 r_count; /* Count of bytes used in the block */
203 } journal_revoke_header_t;
204
205
206 /* Definitions for the journal tag flags word: */
207 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
208 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
209 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
210 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
211
212
213 /*
214 * The journal superblock. All fields are in big-endian byte order.
215 */
216 typedef struct journal_superblock_s
217 {
218 /* 0x0000 */
219 journal_header_t s_header;
220
221 /* 0x000C */
222 /* Static information describing the journal */
223 __be32 s_blocksize; /* journal device blocksize */
224 __be32 s_maxlen; /* total blocks in journal file */
225 __be32 s_first; /* first block of log information */
226
227 /* 0x0018 */
228 /* Dynamic information describing the current state of the log */
229 __be32 s_sequence; /* first commit ID expected in log */
230 __be32 s_start; /* blocknr of start of log */
231
232 /* 0x0020 */
233 /* Error value, as set by journal_abort(). */
234 __be32 s_errno;
235
236 /* 0x0024 */
237 /* Remaining fields are only valid in a version-2 superblock */
238 __be32 s_feature_compat; /* compatible feature set */
239 __be32 s_feature_incompat; /* incompatible feature set */
240 __be32 s_feature_ro_compat; /* readonly-compatible feature set */
241 /* 0x0030 */
242 __u8 s_uuid[16]; /* 128-bit uuid for journal */
243
244 /* 0x0040 */
245 __be32 s_nr_users; /* Nr of filesystems sharing log */
246
247 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
248
249 /* 0x0048 */
250 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
251 __be32 s_max_trans_data; /* Limit of data blocks per trans. */
252
253 /* 0x0050 */
254 __u32 s_padding[44];
255
256 /* 0x0100 */
257 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
258 /* 0x0400 */
259 } journal_superblock_t;
260
261 #define JFS_HAS_COMPAT_FEATURE(j,mask) \
262 ((j)->j_format_version >= 2 && \
263 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
264 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
265 ((j)->j_format_version >= 2 && \
266 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
267 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
268 ((j)->j_format_version >= 2 && \
269 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
270
271 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
272
273 /* Features known to this kernel version: */
274 #define JFS_KNOWN_COMPAT_FEATURES 0
275 #define JFS_KNOWN_ROCOMPAT_FEATURES 0
276 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
277
278 #ifdef __KERNEL__
279
280 #include <linux/fs.h>
281 #include <linux/sched.h>
282
283 #define J_ASSERT ASSERT
284
285 #if defined(CONFIG_BUFFER_DEBUG)
286 void buffer_assertion_failure(struct buffer_head *bh);
287 #define J_ASSERT_BH(bh, expr) \
288 do { \
289 if (!(expr)) \
290 buffer_assertion_failure(bh); \
291 J_ASSERT(expr); \
292 } while (0)
293 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
294 #else
295 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
296 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
297 #endif
298
299 #if defined(JBD_PARANOID_IOFAIL)
300 #define J_EXPECT(expr, why...) J_ASSERT(expr)
301 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
302 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
303 #else
304 #if 0
305 #define __journal_expect(expr, why...) \
306 ({ \
307 int val = (expr); \
308 if (!val) { \
309 printk(KERN_ERR \
310 "EXT3-fs unexpected failure: %s;\n",# expr); \
311 printk(KERN_ERR why "\n"); \
312 } \
313 val; \
314 })
315 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
316 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
317 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
318 #endif
319 #define __journal_expect
320
321 #define J_EXPECT
322 #define J_EXPECT_BH
323 #define J_EXPECT_JH
324
325 #endif
326
327 enum jbd_state_bits {
328 BH_JBD /* Has an attached ext3 journal_head */
329 = BH_PrivateStart,
330 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
331 BH_Freed, /* Has been freed (truncated) */
332 BH_Revoked, /* Has been revoked from the log */
333 BH_RevokeValid, /* Revoked flag is valid */
334 BH_JBDDirty, /* Is dirty but journaled */
335 BH_State, /* Pins most journal_head state */
336 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
337 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
338 };
339
BUFFER_FNS(JBD,jbd)340 BUFFER_FNS(JBD, jbd)
341 BUFFER_FNS(JWrite, jwrite)
342 BUFFER_FNS(JBDDirty, jbddirty)
343 TAS_BUFFER_FNS(JBDDirty, jbddirty)
344 BUFFER_FNS(Revoked, revoked)
345 TAS_BUFFER_FNS(Revoked, revoked)
346 BUFFER_FNS(RevokeValid, revokevalid)
347 TAS_BUFFER_FNS(RevokeValid, revokevalid)
348 BUFFER_FNS(Freed, freed)
349
350 static inline struct buffer_head *jh2bh(struct journal_head *jh)
351 {
352 return jh->b_bh;
353 }
354
bh2jh(struct buffer_head * bh)355 static inline struct journal_head *bh2jh(struct buffer_head *bh)
356 {
357 return bh->b_private;
358 }
359
jbd_lock_bh_state(struct buffer_head * bh)360 static inline void jbd_lock_bh_state(struct buffer_head *bh)
361 {
362 bit_spin_lock(BH_State, &bh->b_state);
363 }
364
jbd_trylock_bh_state(struct buffer_head * bh)365 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
366 {
367 return bit_spin_trylock(BH_State, &bh->b_state);
368 }
369
jbd_is_locked_bh_state(struct buffer_head * bh)370 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
371 {
372 return bit_spin_is_locked(BH_State, &bh->b_state);
373 }
374
jbd_unlock_bh_state(struct buffer_head * bh)375 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
376 {
377 bit_spin_unlock(BH_State, &bh->b_state);
378 }
379
jbd_lock_bh_journal_head(struct buffer_head * bh)380 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
381 {
382 bit_spin_lock(BH_JournalHead, &bh->b_state);
383 }
384
jbd_unlock_bh_journal_head(struct buffer_head * bh)385 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
386 {
387 bit_spin_unlock(BH_JournalHead, &bh->b_state);
388 }
389
390 struct jbd_revoke_table_s;
391
392 /**
393 * struct handle_s - The handle_s type is the concrete type associated with
394 * handle_t.
395 * @h_transaction: Which compound transaction is this update a part of?
396 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
397 * @h_ref: Reference count on this handle
398 * @h_err: Field for caller's use to track errors through large fs operations
399 * @h_sync: flag for sync-on-close
400 * @h_jdata: flag to force data journaling
401 * @h_aborted: flag indicating fatal error on handle
402 * @h_lockdep_map: lockdep info for debugging lock problems
403 **/
404
405 /* Docbook can't yet cope with the bit fields, but will leave the documentation
406 * in so it can be fixed later.
407 */
408
409 struct handle_s
410 {
411 /* Which compound transaction is this update a part of? */
412 transaction_t *h_transaction;
413
414 /* Number of remaining buffers we are allowed to dirty: */
415 int h_buffer_credits;
416
417 /* Reference count on this handle */
418 int h_ref;
419
420 /* Field for caller's use to track errors through large fs */
421 /* operations */
422 int h_err;
423
424 /* Flags [no locking] */
425 unsigned int h_sync:
426 1; /* sync-on-close */
427 unsigned int h_jdata:
428 1; /* force data journaling */
429 unsigned int h_aborted:
430 1; /* fatal error on handle */
431
432 #ifdef CONFIG_DEBUG_LOCK_ALLOC
433 struct lockdep_map h_lockdep_map;
434 #endif
435 };
436
437
438 /* The transaction_t type is the guts of the journaling mechanism. It
439 * tracks a compound transaction through its various states:
440 *
441 * RUNNING: accepting new updates
442 * LOCKED: Updates still running but we don't accept new ones
443 * RUNDOWN: Updates are tidying up but have finished requesting
444 * new buffers to modify (state not used for now)
445 * FLUSH: All updates complete, but we are still writing to disk
446 * COMMIT: All data on disk, writing commit record
447 * FINISHED: We still have to keep the transaction for checkpointing.
448 *
449 * The transaction keeps track of all of the buffers modified by a
450 * running transaction, and all of the buffers committed but not yet
451 * flushed to home for finished transactions.
452 */
453
454 /*
455 * Lock ranking:
456 *
457 * j_list_lock
458 * ->jbd_lock_bh_journal_head() (This is "innermost")
459 *
460 * j_state_lock
461 * ->jbd_lock_bh_state()
462 *
463 * jbd_lock_bh_state()
464 * ->j_list_lock
465 *
466 * j_state_lock
467 * ->t_handle_lock
468 *
469 * j_state_lock
470 * ->j_list_lock (journal_unmap_buffer)
471 *
472 */
473
474 struct transaction_s
475 {
476 /* Pointer to the journal for this transaction. [no locking] */
477 journal_t *t_journal;
478
479 /* Sequence number for this transaction [no locking] */
480 tid_t t_tid;
481
482 /*
483 * Transaction's current state
484 * [no locking - only kjournald alters this]
485 * [j_list_lock] guards transition of a transaction into T_FINISHED
486 * state and subsequent call of __journal_drop_transaction()
487 * FIXME: needs barriers
488 * KLUDGE: [use j_state_lock]
489 */
490 enum {
491 T_RUNNING,
492 T_LOCKED,
493 T_RUNDOWN,
494 T_FLUSH,
495 T_COMMIT,
496 T_FINISHED
497 } t_state;
498
499 /*
500 * Where in the log does this transaction's commit start? [no locking]
501 */
502 unsigned long t_log_start;
503
504 /* Number of buffers on the t_buffers list [j_list_lock] */
505 int t_nr_buffers;
506
507 /*
508 * Doubly-linked circular list of all buffers reserved but not yet
509 * modified by this transaction [j_list_lock]
510 */
511 struct journal_head *t_reserved_list;
512
513 /*
514 * Doubly-linked circular list of all buffers under writeout during
515 * commit [j_list_lock]
516 */
517 struct journal_head *t_locked_list;
518
519 /*
520 * Doubly-linked circular list of all metadata buffers owned by this
521 * transaction [j_list_lock]
522 */
523 struct journal_head *t_buffers;
524
525 /*
526 * Doubly-linked circular list of all data buffers still to be
527 * flushed before this transaction can be committed [j_list_lock]
528 */
529 struct journal_head *t_sync_datalist;
530
531 /*
532 * Doubly-linked circular list of all forget buffers (superseded
533 * buffers which we can un-checkpoint once this transaction commits)
534 * [j_list_lock]
535 */
536 struct journal_head *t_forget;
537
538 /*
539 * Doubly-linked circular list of all buffers still to be flushed before
540 * this transaction can be checkpointed. [j_list_lock]
541 */
542 struct journal_head *t_checkpoint_list;
543
544 /*
545 * Doubly-linked circular list of all buffers submitted for IO while
546 * checkpointing. [j_list_lock]
547 */
548 struct journal_head *t_checkpoint_io_list;
549
550 /*
551 * Doubly-linked circular list of temporary buffers currently undergoing
552 * IO in the log [j_list_lock]
553 */
554 struct journal_head *t_iobuf_list;
555
556 /*
557 * Doubly-linked circular list of metadata buffers being shadowed by log
558 * IO. The IO buffers on the iobuf list and the shadow buffers on this
559 * list match each other one for one at all times. [j_list_lock]
560 */
561 struct journal_head *t_shadow_list;
562
563 /*
564 * Doubly-linked circular list of control buffers being written to the
565 * log. [j_list_lock]
566 */
567 struct journal_head *t_log_list;
568
569 /*
570 * Protects info related to handles
571 */
572 jbdlock_t t_handle_lock;
573
574 /*
575 * Number of outstanding updates running on this transaction
576 * [t_handle_lock]
577 */
578 int t_updates;
579
580 /*
581 * Number of buffers reserved for use by all handles in this transaction
582 * handle but not yet modified. [t_handle_lock]
583 */
584 int t_outstanding_credits;
585
586 /*
587 * Forward and backward links for the circular list of all transactions
588 * awaiting checkpoint. [j_list_lock]
589 */
590 transaction_t *t_cpnext, *t_cpprev;
591
592 /*
593 * When will the transaction expire (become due for commit), in jiffies?
594 * [no locking]
595 */
596 unsigned long t_expires;
597
598 /*
599 * How many handles used this transaction? [t_handle_lock]
600 */
601 int t_handle_count;
602
603 };
604
605 /**
606 * struct journal_s - The journal_s type is the concrete type associated with
607 * journal_t.
608 * @j_flags: General journaling state flags
609 * @j_errno: Is there an outstanding uncleared error on the journal (from a
610 * prior abort)?
611 * @j_sb_buffer: First part of superblock buffer
612 * @j_superblock: Second part of superblock buffer
613 * @j_format_version: Version of the superblock format
614 * @j_state_lock: Protect the various scalars in the journal
615 * @j_barrier_count: Number of processes waiting to create a barrier lock
616 * @j_barrier: The barrier lock itself
617 * @j_running_transaction: The current running transaction..
618 * @j_committing_transaction: the transaction we are pushing to disk
619 * @j_checkpoint_transactions: a linked circular list of all transactions
620 * waiting for checkpointing
621 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
622 * to start committing, or for a barrier lock to be released
623 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
624 * @j_wait_done_commit: Wait queue for waiting for commit to complete
625 * @j_wait_checkpoint: Wait queue to trigger checkpointing
626 * @j_wait_commit: Wait queue to trigger commit
627 * @j_wait_updates: Wait queue to wait for updates to complete
628 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
629 * @j_head: Journal head - identifies the first unused block in the journal
630 * @j_tail: Journal tail - identifies the oldest still-used block in the
631 * journal.
632 * @j_free: Journal free - how many free blocks are there in the journal?
633 * @j_first: The block number of the first usable block
634 * @j_last: The block number one beyond the last usable block
635 * @j_dev: Device where we store the journal
636 * @j_blocksize: blocksize for the location where we store the journal.
637 * @j_blk_offset: starting block offset for into the device where we store the
638 * journal
639 * @j_fs_dev: Device which holds the client fs. For internal journal this will
640 * be equal to j_dev
641 * @j_maxlen: Total maximum capacity of the journal region on disk.
642 * @j_list_lock: Protects the buffer lists and internal buffer state.
643 * @j_inode: Optional inode where we store the journal. If present, all journal
644 * block numbers are mapped into this inode via bmap().
645 * @j_tail_sequence: Sequence number of the oldest transaction in the log
646 * @j_transaction_sequence: Sequence number of the next transaction to grant
647 * @j_commit_sequence: Sequence number of the most recently committed
648 * transaction
649 * @j_commit_request: Sequence number of the most recent transaction wanting
650 * commit
651 * @j_uuid: Uuid of client object.
652 * @j_task: Pointer to the current commit thread for this journal
653 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
654 * single compound commit transaction
655 * @j_commit_interval: What is the maximum transaction lifetime before we begin
656 * a commit?
657 * @j_commit_timer: The timer used to wakeup the commit thread
658 * @j_revoke_lock: Protect the revoke table
659 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
660 * current transaction.
661 * @j_revoke_table: alternate revoke tables for j_revoke
662 * @j_wbuf: array of buffer_heads for journal_commit_transaction
663 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
664 * number that will fit in j_blocksize
665 * @j_last_sync_writer: most recent pid which did a synchronous write
666 * @j_private: An opaque pointer to fs-private information.
667 */
668
669 struct journal_s
670 {
671 /* General journaling state flags [j_state_lock] */
672 unsigned long j_flags;
673
674 /*
675 * Is there an outstanding uncleared error on the journal (from a prior
676 * abort)? [j_state_lock]
677 */
678 int j_errno;
679
680 /* The superblock buffer */
681 struct buffer_head *j_sb_buffer;
682 journal_superblock_t *j_superblock;
683
684 /* Version of the superblock format */
685 int j_format_version;
686
687 /*
688 * Protect the various scalars in the journal
689 */
690 jbdlock_t j_state_lock;
691
692 /*
693 * Number of processes waiting to create a barrier lock [j_state_lock]
694 */
695 int j_barrier_count;
696
697 /* The barrier lock itself */
698 struct mutex j_barrier;
699
700 /*
701 * Transactions: The current running transaction...
702 * [j_state_lock] [caller holding open handle]
703 */
704 transaction_t *j_running_transaction;
705
706 /*
707 * the transaction we are pushing to disk
708 * [j_state_lock] [caller holding open handle]
709 */
710 transaction_t *j_committing_transaction;
711
712 /*
713 * ... and a linked circular list of all transactions waiting for
714 * checkpointing. [j_list_lock]
715 */
716 transaction_t *j_checkpoint_transactions;
717
718 /*
719 * Wait queue for waiting for a locked transaction to start committing,
720 * or for a barrier lock to be released
721 */
722 wait_queue_head_t j_wait_transaction_locked;
723
724 /* Wait queue for waiting for checkpointing to complete */
725 wait_queue_head_t j_wait_logspace;
726
727 /* Wait queue for waiting for commit to complete */
728 wait_queue_head_t j_wait_done_commit;
729
730 /* Wait queue to trigger checkpointing */
731 wait_queue_head_t j_wait_checkpoint;
732
733 /* Wait queue to trigger commit */
734 wait_queue_head_t j_wait_commit;
735
736 /* Wait queue to wait for updates to complete */
737 wait_queue_head_t j_wait_updates;
738
739 /* Semaphore for locking against concurrent checkpoints */
740 struct mutex j_checkpoint_mutex;
741
742 /*
743 * Journal head: identifies the first unused block in the journal.
744 * [j_state_lock]
745 */
746 unsigned long j_head;
747
748 /*
749 * Journal tail: identifies the oldest still-used block in the journal.
750 * [j_state_lock]
751 */
752 unsigned long j_tail;
753
754 /*
755 * Journal free: how many free blocks are there in the journal?
756 * [j_state_lock]
757 */
758 unsigned long j_free;
759
760 /*
761 * Journal start and end: the block numbers of the first usable block
762 * and one beyond the last usable block in the journal. [j_state_lock]
763 */
764 unsigned long j_first;
765 unsigned long j_last;
766
767 /*
768 * Device, blocksize and starting block offset for the location where we
769 * store the journal.
770 */
771 struct block_device *j_dev;
772 int j_blocksize;
773 unsigned long j_blk_offset;
774
775 /*
776 * Device which holds the client fs. For internal journal this will be
777 * equal to j_dev.
778 */
779 struct block_device *j_fs_dev;
780
781 /* Total maximum capacity of the journal region on disk. */
782 unsigned int j_maxlen;
783
784 /*
785 * Protects the buffer lists and internal buffer state.
786 */
787 jbdlock_t j_list_lock;
788
789 /* Optional inode where we store the journal. If present, all */
790 /* journal block numbers are mapped into this inode via */
791 /* bmap(). */
792 struct inode *j_inode;
793
794 /*
795 * Sequence number of the oldest transaction in the log [j_state_lock]
796 */
797 tid_t j_tail_sequence;
798
799 /*
800 * Sequence number of the next transaction to grant [j_state_lock]
801 */
802 tid_t j_transaction_sequence;
803
804 /*
805 * Sequence number of the most recently committed transaction
806 * [j_state_lock].
807 */
808 tid_t j_commit_sequence;
809
810 /*
811 * Sequence number of the most recent transaction wanting commit
812 * [j_state_lock]
813 */
814 tid_t j_commit_request;
815
816 /*
817 * Journal uuid: identifies the object (filesystem, LVM volume etc)
818 * backed by this journal. This will eventually be replaced by an array
819 * of uuids, allowing us to index multiple devices within a single
820 * journal and to perform atomic updates across them.
821 */
822 __u8 j_uuid[16];
823
824 /* Pointer to the current commit thread for this journal */
825 struct task_struct *j_task;
826
827 /*
828 * Maximum number of metadata buffers to allow in a single compound
829 * commit transaction
830 */
831 int j_max_transaction_buffers;
832
833 /*
834 * What is the maximum transaction lifetime before we begin a commit?
835 */
836 unsigned long j_commit_interval;
837
838 /* The timer used to wakeup the commit thread: */
839 struct timer_list j_commit_timer;
840
841 /*
842 * The revoke table: maintains the list of revoked blocks in the
843 * current transaction. [j_revoke_lock]
844 */
845 jbdlock_t j_revoke_lock;
846 struct jbd_revoke_table_s *j_revoke;
847 struct jbd_revoke_table_s *j_revoke_table[2];
848
849 /*
850 * array of bhs for journal_commit_transaction
851 */
852 struct buffer_head **j_wbuf;
853 int j_wbufsize;
854
855 pid_t j_last_sync_writer;
856
857 /*
858 * An opaque pointer to fs-private information. ext3 puts its
859 * superblock pointer here
860 */
861 void *j_private;
862 };
863
864 /*
865 * Journal flag definitions
866 */
867 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
868 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
869 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
870 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
871 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
872 #define JFS_BARRIER 0x020 /* Use IDE barriers */
873
874 /*
875 * Function declarations for the journaling transaction and buffer
876 * management
877 */
878
879 /* Filing buffers */
880 extern void journal_unfile_buffer(journal_t *, struct journal_head *);
881 extern void __journal_unfile_buffer(struct journal_head *);
882 extern void __journal_refile_buffer(struct journal_head *);
883 extern void journal_refile_buffer(journal_t *, struct journal_head *);
884 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
885 extern void __journal_free_buffer(struct journal_head *bh);
886 extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
887 extern void __journal_clean_data_list(transaction_t *transaction);
888
889 /* Log buffer allocation */
890 extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
891 int journal_next_log_block(journal_t *, unsigned long *);
892
893 /* Commit management */
894 extern void journal_commit_transaction(journal_t *);
895
896 /* Checkpoint list management */
897 int __journal_clean_checkpoint_list(journal_t *journal);
898 int __journal_remove_checkpoint(struct journal_head *);
899 void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
900
901 /* Buffer IO */
902 extern int
903 journal_write_metadata_buffer(transaction_t *transaction,
904 struct journal_head *jh_in,
905 struct journal_head **jh_out,
906 unsigned long blocknr);
907
908 /* Transaction locking */
909 extern void __wait_on_journal (journal_t *);
910
911 /*
912 * Journal locking.
913 *
914 * We need to lock the journal during transaction state changes so that nobody
915 * ever tries to take a handle on the running transaction while we are in the
916 * middle of moving it to the commit phase. j_state_lock does this.
917 *
918 * Note that the locking is completely interrupt unsafe. We never touch
919 * journal structures from interrupts.
920 */
921
journal_current_handle(void)922 static inline handle_t *journal_current_handle(void)
923 {
924 return NULL;
925 /* return current->journal_info; */
926 #ifdef _MSC_VER
927 #pragma message("WARNINGS: journal_current_handle NOT implemented")
928 #endif
929 }
930
931 /* The journaling code user interface:
932 *
933 * Create and destroy handles
934 * Register buffer modifications against the current transaction.
935 */
936
937 extern handle_t *journal_start(journal_t *, int nblocks);
938 extern int journal_restart (handle_t *, int nblocks);
939 extern int journal_extend (handle_t *, int nblocks);
940 extern int journal_get_write_access(handle_t *, struct buffer_head *);
941 extern int journal_get_create_access (handle_t *, struct buffer_head *);
942 extern int journal_get_undo_access(handle_t *, struct buffer_head *);
943 extern int journal_dirty_data (handle_t *, struct buffer_head *);
944 extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
945 extern void journal_release_buffer (handle_t *, struct buffer_head *);
946 extern int journal_forget (handle_t *, struct buffer_head *);
947 extern void journal_sync_buffer (struct buffer_head *);
948 extern void journal_invalidatepage(journal_t *,
949 struct page *, unsigned long);
950 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
951 extern int journal_stop(handle_t *);
952 extern int journal_flush (journal_t *);
953 extern void journal_lock_updates (journal_t *);
954 extern void journal_unlock_updates (journal_t *);
955
956 extern journal_t * journal_init_dev(struct block_device *bdev,
957 struct block_device *fs_dev,
958 int start, int len, int bsize);
959 extern journal_t * journal_init_inode (struct inode *);
960 extern int journal_update_format (journal_t *);
961 extern int journal_check_used_features
962 (journal_t *, unsigned long, unsigned long, unsigned long);
963 extern int journal_check_available_features
964 (journal_t *, unsigned long, unsigned long, unsigned long);
965 extern int journal_set_features
966 (journal_t *, unsigned long, unsigned long, unsigned long);
967 extern int journal_create (journal_t *);
968 extern int journal_load (journal_t *journal);
969 extern void journal_destroy (journal_t *);
970 extern int journal_recover (journal_t *journal);
971 extern int journal_wipe (journal_t *, int);
972 extern int journal_skip_recovery (journal_t *);
973 extern void journal_update_superblock (journal_t *, int);
974 void journal_abort (journal_t *, int);
975 extern int journal_errno (journal_t *);
976 extern void journal_ack_err (journal_t *);
977 extern int journal_clear_err (journal_t *);
978 extern int journal_bmap(journal_t *, unsigned long, unsigned long *);
979 extern int journal_force_commit(journal_t *);
980
981 /* added by matt */
982 void journal_wipe_recovery(journal_t *journal);
983
984 /*
985 * journal_head management
986 */
987 struct journal_head *journal_add_journal_head(struct buffer_head *bh);
988 struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
989 void journal_remove_journal_head(struct buffer_head *bh);
990 void journal_put_journal_head(struct journal_head *jh);
991
992 /*
993 * handle management
994 */
995 extern struct kmem_cache *jbd_handle_cache;
996
jbd_alloc_handle(gfp_t gfp_flags)997 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
998 {
999 return (handle_t *)kmem_cache_alloc(jbd_handle_cache, gfp_flags);
1000 }
1001
jbd_free_handle(handle_t * handle)1002 static inline void jbd_free_handle(handle_t *handle)
1003 {
1004 kmem_cache_free(jbd_handle_cache, handle);
1005 }
1006
1007 /* Primary revoke support */
1008 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1009 extern int journal_init_revoke(journal_t *, int);
1010 extern void journal_destroy_revoke_caches(void);
1011 extern int journal_init_revoke_caches(void);
1012
1013 extern void journal_destroy_revoke(journal_t *);
1014 extern int journal_revoke (handle_t *,
1015 unsigned long, struct buffer_head *);
1016 extern int journal_cancel_revoke(handle_t *, struct journal_head *);
1017 extern void journal_write_revoke_records(journal_t *, transaction_t *);
1018
1019 /* Recovery revoke support */
1020 extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
1021 extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
1022 extern void journal_clear_revoke(journal_t *);
1023 extern void journal_switch_revoke_table(journal_t *journal);
1024
1025 /*
1026 * The log thread user interface:
1027 *
1028 * Request space in the current transaction, and force transaction commit
1029 * transitions on demand.
1030 */
1031
1032 int __log_space_left(journal_t *); /* Called with journal locked */
1033 int log_start_commit(journal_t *journal, tid_t tid);
1034 int __log_start_commit(journal_t *journal, tid_t tid);
1035 int journal_start_commit(journal_t *journal, tid_t *tid);
1036 int journal_force_commit_nested(journal_t *journal);
1037 int log_wait_commit(journal_t *journal, tid_t tid);
1038 int log_do_checkpoint(journal_t *journal);
1039
1040 void __log_wait_for_space(journal_t *journal);
1041 extern void __journal_drop_transaction(journal_t *, transaction_t *);
1042 extern int cleanup_journal_tail(journal_t *);
1043
1044 /* Debugging code only: */
1045
1046 #define jbd_ENOSYS() \
1047 do { \
1048 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1049 current->state = TASK_UNINTERRUPTIBLE; \
1050 schedule(); \
1051 } while (1)
1052
1053 /*
1054 * is_journal_abort
1055 *
1056 * Simple test wrapper function to test the JFS_ABORT state flag. This
1057 * bit, when set, indicates that we have had a fatal error somewhere,
1058 * either inside the journaling layer or indicated to us by the client
1059 * (eg. ext3), and that we and should not commit any further
1060 * transactions.
1061 */
1062
is_journal_aborted(journal_t * journal)1063 static inline int is_journal_aborted(journal_t *journal)
1064 {
1065 return journal->j_flags & JFS_ABORT;
1066 }
1067
is_handle_aborted(handle_t * handle)1068 static inline int is_handle_aborted(handle_t *handle)
1069 {
1070 if (handle->h_aborted)
1071 return 1;
1072 return is_journal_aborted(handle->h_transaction->t_journal);
1073 }
1074
journal_abort_handle(handle_t * handle)1075 static inline void journal_abort_handle(handle_t *handle)
1076 {
1077 handle->h_aborted = 1;
1078 }
1079
1080 #endif /* __KERNEL__ */
1081
1082 /* Comparison functions for transaction IDs: perform comparisons using
1083 * modulo arithmetic so that they work over sequence number wraps. */
1084
tid_gt(tid_t x,tid_t y)1085 static inline int tid_gt(tid_t x, tid_t y)
1086 {
1087 int difference = (x - y);
1088 return (difference > 0);
1089 }
1090
tid_geq(tid_t x,tid_t y)1091 static inline int tid_geq(tid_t x, tid_t y)
1092 {
1093 int difference = (x - y);
1094 return (difference >= 0);
1095 }
1096
1097 extern int journal_blocks_per_page(struct inode *inode);
1098
1099 /*
1100 * Return the minimum number of blocks which must be free in the journal
1101 * before a new transaction may be started. Must be called under j_state_lock.
1102 */
jbd_space_needed(journal_t * journal)1103 static inline int jbd_space_needed(journal_t *journal)
1104 {
1105 int nblocks = journal->j_max_transaction_buffers;
1106 if (journal->j_committing_transaction)
1107 nblocks += journal->j_committing_transaction->
1108 t_outstanding_credits;
1109 return nblocks;
1110 }
1111
1112 /*
1113 * Definitions which augment the buffer_head layer
1114 */
1115
1116 /* journaling buffer types */
1117 #define BJ_None 0 /* Not journaled */
1118 #define BJ_SyncData 1 /* Normal data: flush before commit */
1119 #define BJ_Metadata 2 /* Normal journaled metadata */
1120 #define BJ_Forget 3 /* Buffer superseded by this transaction */
1121 #define BJ_IO 4 /* Buffer is for temporary IO use */
1122 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1123 #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1124 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1125 #define BJ_Locked 8 /* Locked for I/O during commit */
1126 #define BJ_Types 9
1127
1128 extern int jbd_blocks_per_page(struct inode *inode);
1129
1130 #ifdef __KERNEL__
1131
1132 #define buffer_trace_init(bh) do {} while (0)
1133 #define print_buffer_fields(bh) do {} while (0)
1134 #define print_buffer_trace(bh) do {} while (0)
1135 #define BUFFER_TRACE(bh, info) do {} while (0)
1136 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1137 #define JBUFFER_TRACE(jh, info) do {} while (0)
1138
1139 #endif /* __KERNEL__ */
1140
1141 #endif /* _LINUX_JBD_H */
1142