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[/] [test_project/] [trunk/] [linux_sd_driver/] [include/] [linux/] [jbd.h] - Blame information for rev 62

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1 62 marcus.erl
/*
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/types.h>
27
#include <linux/buffer_head.h>
28
#include <linux/journal-head.h>
29
#include <linux/stddef.h>
30
#include <linux/bit_spinlock.h>
31
#include <linux/mutex.h>
32
#include <linux/timer.h>
33
#include <linux/lockdep.h>
34
 
35
#include <asm/semaphore.h>
36
#endif
37
 
38
#define journal_oom_retry 1
39
 
40
/*
41
 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds
42
 * certain classes of error which can occur due to failed IOs.  Under
43
 * normal use we want ext3 to continue after such errors, because
44
 * hardware _can_ fail, but for debugging purposes when running tests on
45
 * known-good hardware we may want to trap these errors.
46
 */
47
#undef JBD_PARANOID_IOFAIL
48
 
49
/*
50
 * The default maximum commit age, in seconds.
51
 */
52
#define JBD_DEFAULT_MAX_COMMIT_AGE 5
53
 
54
#ifdef CONFIG_JBD_DEBUG
55
/*
56
 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
57
 * consistency checks.  By default we don't do this unless
58
 * CONFIG_JBD_DEBUG is on.
59
 */
60
#define JBD_EXPENSIVE_CHECKING
61
extern u8 journal_enable_debug;
62
 
63
#define jbd_debug(n, f, a...)                                           \
64
        do {                                                            \
65
                if ((n) <= journal_enable_debug) {                      \
66
                        printk (KERN_DEBUG "(%s, %d): %s: ",            \
67
                                __FILE__, __LINE__, __FUNCTION__);      \
68
                        printk (f, ## a);                               \
69
                }                                                       \
70
        } while (0)
71
#else
72
#define jbd_debug(f, a...)      /**/
73
#endif
74
 
75
static inline void *jbd_alloc(size_t size, gfp_t flags)
76
{
77
        return (void *)__get_free_pages(flags, get_order(size));
78
}
79
 
80
static inline void jbd_free(void *ptr, size_t size)
81
{
82
        free_pages((unsigned long)ptr, get_order(size));
83
};
84
 
85
#define JFS_MIN_JOURNAL_BLOCKS 1024
86
 
87
#ifdef __KERNEL__
88
 
89
/**
90
 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
91
 *
92
 * All filesystem modifications made by the process go
93
 * through this handle.  Recursive operations (such as quota operations)
94
 * are gathered into a single update.
95
 *
96
 * The buffer credits field is used to account for journaled buffers
97
 * being modified by the running process.  To ensure that there is
98
 * enough log space for all outstanding operations, we need to limit the
99
 * number of outstanding buffers possible at any time.  When the
100
 * operation completes, any buffer credits not used are credited back to
101
 * the transaction, so that at all times we know how many buffers the
102
 * outstanding updates on a transaction might possibly touch.
103
 *
104
 * This is an opaque datatype.
105
 **/
106
typedef struct handle_s         handle_t;       /* Atomic operation type */
107
 
108
 
109
/**
110
 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
111
 *
112
 * journal_t is linked to from the fs superblock structure.
113
 *
114
 * We use the journal_t to keep track of all outstanding transaction
115
 * activity on the filesystem, and to manage the state of the log
116
 * writing process.
117
 *
118
 * This is an opaque datatype.
119
 **/
120
typedef struct journal_s        journal_t;      /* Journal control structure */
121
#endif
122
 
123
/*
124
 * Internal structures used by the logging mechanism:
125
 */
126
 
127
#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
128
 
129
/*
130
 * On-disk structures
131
 */
132
 
133
/*
134
 * Descriptor block types:
135
 */
136
 
137
#define JFS_DESCRIPTOR_BLOCK    1
138
#define JFS_COMMIT_BLOCK        2
139
#define JFS_SUPERBLOCK_V1       3
140
#define JFS_SUPERBLOCK_V2       4
141
#define JFS_REVOKE_BLOCK        5
142
 
143
/*
144
 * Standard header for all descriptor blocks:
145
 */
146
typedef struct journal_header_s
147
{
148
        __be32          h_magic;
149
        __be32          h_blocktype;
150
        __be32          h_sequence;
151
} journal_header_t;
152
 
153
 
154
/*
155
 * The block tag: used to describe a single buffer in the journal
156
 */
157
typedef struct journal_block_tag_s
158
{
159
        __be32          t_blocknr;      /* The on-disk block number */
160
        __be32          t_flags;        /* See below */
161
} journal_block_tag_t;
162
 
163
/*
164
 * The revoke descriptor: used on disk to describe a series of blocks to
165
 * be revoked from the log
166
 */
167
typedef struct journal_revoke_header_s
168
{
169
        journal_header_t r_header;
170
        __be32           r_count;       /* Count of bytes used in the block */
171
} journal_revoke_header_t;
172
 
173
 
174
/* Definitions for the journal tag flags word: */
175
#define JFS_FLAG_ESCAPE         1       /* on-disk block is escaped */
176
#define JFS_FLAG_SAME_UUID      2       /* block has same uuid as previous */
177
#define JFS_FLAG_DELETED        4       /* block deleted by this transaction */
178
#define JFS_FLAG_LAST_TAG       8       /* last tag in this descriptor block */
179
 
180
 
181
/*
182
 * The journal superblock.  All fields are in big-endian byte order.
183
 */
184
typedef struct journal_superblock_s
185
{
186
/* 0x0000 */
187
        journal_header_t s_header;
188
 
189
/* 0x000C */
190
        /* Static information describing the journal */
191
        __be32  s_blocksize;            /* journal device blocksize */
192
        __be32  s_maxlen;               /* total blocks in journal file */
193
        __be32  s_first;                /* first block of log information */
194
 
195
/* 0x0018 */
196
        /* Dynamic information describing the current state of the log */
197
        __be32  s_sequence;             /* first commit ID expected in log */
198
        __be32  s_start;                /* blocknr of start of log */
199
 
200
/* 0x0020 */
201
        /* Error value, as set by journal_abort(). */
202
        __be32  s_errno;
203
 
204
/* 0x0024 */
205
        /* Remaining fields are only valid in a version-2 superblock */
206
        __be32  s_feature_compat;       /* compatible feature set */
207
        __be32  s_feature_incompat;     /* incompatible feature set */
208
        __be32  s_feature_ro_compat;    /* readonly-compatible feature set */
209
/* 0x0030 */
210
        __u8    s_uuid[16];             /* 128-bit uuid for journal */
211
 
212
/* 0x0040 */
213
        __be32  s_nr_users;             /* Nr of filesystems sharing log */
214
 
215
        __be32  s_dynsuper;             /* Blocknr of dynamic superblock copy*/
216
 
217
/* 0x0048 */
218
        __be32  s_max_transaction;      /* Limit of journal blocks per trans.*/
219
        __be32  s_max_trans_data;       /* Limit of data blocks per trans. */
220
 
221
/* 0x0050 */
222
        __u32   s_padding[44];
223
 
224
/* 0x0100 */
225
        __u8    s_users[16*48];         /* ids of all fs'es sharing the log */
226
/* 0x0400 */
227
} journal_superblock_t;
228
 
229
#define JFS_HAS_COMPAT_FEATURE(j,mask)                                  \
230
        ((j)->j_format_version >= 2 &&                                  \
231
         ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
232
#define JFS_HAS_RO_COMPAT_FEATURE(j,mask)                               \
233
        ((j)->j_format_version >= 2 &&                                  \
234
         ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
235
#define JFS_HAS_INCOMPAT_FEATURE(j,mask)                                \
236
        ((j)->j_format_version >= 2 &&                                  \
237
         ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
238
 
239
#define JFS_FEATURE_INCOMPAT_REVOKE     0x00000001
240
 
241
/* Features known to this kernel version: */
242
#define JFS_KNOWN_COMPAT_FEATURES       0
243
#define JFS_KNOWN_ROCOMPAT_FEATURES     0
244
#define JFS_KNOWN_INCOMPAT_FEATURES     JFS_FEATURE_INCOMPAT_REVOKE
245
 
246
#ifdef __KERNEL__
247
 
248
#include <linux/fs.h>
249
#include <linux/sched.h>
250
 
251
#define J_ASSERT(assert)        BUG_ON(!(assert))
252
 
253
#if defined(CONFIG_BUFFER_DEBUG)
254
void buffer_assertion_failure(struct buffer_head *bh);
255
#define J_ASSERT_BH(bh, expr)                                           \
256
        do {                                                            \
257
                if (!(expr))                                            \
258
                        buffer_assertion_failure(bh);                   \
259
                J_ASSERT(expr);                                         \
260
        } while (0)
261
#define J_ASSERT_JH(jh, expr)   J_ASSERT_BH(jh2bh(jh), expr)
262
#else
263
#define J_ASSERT_BH(bh, expr)   J_ASSERT(expr)
264
#define J_ASSERT_JH(jh, expr)   J_ASSERT(expr)
265
#endif
266
 
267
#if defined(JBD_PARANOID_IOFAIL)
268
#define J_EXPECT(expr, why...)          J_ASSERT(expr)
269
#define J_EXPECT_BH(bh, expr, why...)   J_ASSERT_BH(bh, expr)
270
#define J_EXPECT_JH(jh, expr, why...)   J_ASSERT_JH(jh, expr)
271
#else
272
#define __journal_expect(expr, why...)                                       \
273
        ({                                                                   \
274
                int val = (expr);                                            \
275
                if (!val) {                                                  \
276
                        printk(KERN_ERR                                      \
277
                                "EXT3-fs unexpected failure: %s;\n",# expr); \
278
                        printk(KERN_ERR why "\n");                           \
279
                }                                                            \
280
                val;                                                         \
281
        })
282
#define J_EXPECT(expr, why...)          __journal_expect(expr, ## why)
283
#define J_EXPECT_BH(bh, expr, why...)   __journal_expect(expr, ## why)
284
#define J_EXPECT_JH(jh, expr, why...)   __journal_expect(expr, ## why)
285
#endif
286
 
287
enum jbd_state_bits {
288
        BH_JBD                  /* Has an attached ext3 journal_head */
289
          = BH_PrivateStart,
290
        BH_JWrite,              /* Being written to log (@@@ DEBUGGING) */
291
        BH_Freed,               /* Has been freed (truncated) */
292
        BH_Revoked,             /* Has been revoked from the log */
293
        BH_RevokeValid,         /* Revoked flag is valid */
294
        BH_JBDDirty,            /* Is dirty but journaled */
295
        BH_State,               /* Pins most journal_head state */
296
        BH_JournalHead,         /* Pins bh->b_private and jh->b_bh */
297
        BH_Unshadow,            /* Dummy bit, for BJ_Shadow wakeup filtering */
298
};
299
 
300
BUFFER_FNS(JBD, jbd)
301
BUFFER_FNS(JWrite, jwrite)
302
BUFFER_FNS(JBDDirty, jbddirty)
303
TAS_BUFFER_FNS(JBDDirty, jbddirty)
304
BUFFER_FNS(Revoked, revoked)
305
TAS_BUFFER_FNS(Revoked, revoked)
306
BUFFER_FNS(RevokeValid, revokevalid)
307
TAS_BUFFER_FNS(RevokeValid, revokevalid)
308
BUFFER_FNS(Freed, freed)
309
 
310
static inline struct buffer_head *jh2bh(struct journal_head *jh)
311
{
312
        return jh->b_bh;
313
}
314
 
315
static inline struct journal_head *bh2jh(struct buffer_head *bh)
316
{
317
        return bh->b_private;
318
}
319
 
320
static inline void jbd_lock_bh_state(struct buffer_head *bh)
321
{
322
        bit_spin_lock(BH_State, &bh->b_state);
323
}
324
 
325
static inline int jbd_trylock_bh_state(struct buffer_head *bh)
326
{
327
        return bit_spin_trylock(BH_State, &bh->b_state);
328
}
329
 
330
static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
331
{
332
        return bit_spin_is_locked(BH_State, &bh->b_state);
333
}
334
 
335
static inline void jbd_unlock_bh_state(struct buffer_head *bh)
336
{
337
        bit_spin_unlock(BH_State, &bh->b_state);
338
}
339
 
340
static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
341
{
342
        bit_spin_lock(BH_JournalHead, &bh->b_state);
343
}
344
 
345
static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
346
{
347
        bit_spin_unlock(BH_JournalHead, &bh->b_state);
348
}
349
 
350
struct jbd_revoke_table_s;
351
 
352
/**
353
 * struct handle_s - The handle_s type is the concrete type associated with
354
 *     handle_t.
355
 * @h_transaction: Which compound transaction is this update a part of?
356
 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
357
 * @h_ref: Reference count on this handle
358
 * @h_err: Field for caller's use to track errors through large fs operations
359
 * @h_sync: flag for sync-on-close
360
 * @h_jdata: flag to force data journaling
361
 * @h_aborted: flag indicating fatal error on handle
362
 * @h_lockdep_map: lockdep info for debugging lock problems
363
 **/
364
 
365
/* Docbook can't yet cope with the bit fields, but will leave the documentation
366
 * in so it can be fixed later.
367
 */
368
 
369
struct handle_s
370
{
371
        /* Which compound transaction is this update a part of? */
372
        transaction_t           *h_transaction;
373
 
374
        /* Number of remaining buffers we are allowed to dirty: */
375
        int                     h_buffer_credits;
376
 
377
        /* Reference count on this handle */
378
        int                     h_ref;
379
 
380
        /* Field for caller's use to track errors through large fs */
381
        /* operations */
382
        int                     h_err;
383
 
384
        /* Flags [no locking] */
385
        unsigned int    h_sync:         1;      /* sync-on-close */
386
        unsigned int    h_jdata:        1;      /* force data journaling */
387
        unsigned int    h_aborted:      1;      /* fatal error on handle */
388
 
389
#ifdef CONFIG_DEBUG_LOCK_ALLOC
390
        struct lockdep_map      h_lockdep_map;
391
#endif
392
};
393
 
394
 
395
/* The transaction_t type is the guts of the journaling mechanism.  It
396
 * tracks a compound transaction through its various states:
397
 *
398
 * RUNNING:     accepting new updates
399
 * LOCKED:      Updates still running but we don't accept new ones
400
 * RUNDOWN:     Updates are tidying up but have finished requesting
401
 *              new buffers to modify (state not used for now)
402
 * FLUSH:       All updates complete, but we are still writing to disk
403
 * COMMIT:      All data on disk, writing commit record
404
 * FINISHED:    We still have to keep the transaction for checkpointing.
405
 *
406
 * The transaction keeps track of all of the buffers modified by a
407
 * running transaction, and all of the buffers committed but not yet
408
 * flushed to home for finished transactions.
409
 */
410
 
411
/*
412
 * Lock ranking:
413
 *
414
 *    j_list_lock
415
 *      ->jbd_lock_bh_journal_head()    (This is "innermost")
416
 *
417
 *    j_state_lock
418
 *    ->jbd_lock_bh_state()
419
 *
420
 *    jbd_lock_bh_state()
421
 *    ->j_list_lock
422
 *
423
 *    j_state_lock
424
 *    ->t_handle_lock
425
 *
426
 *    j_state_lock
427
 *    ->j_list_lock                     (journal_unmap_buffer)
428
 *
429
 */
430
 
431
struct transaction_s
432
{
433
        /* Pointer to the journal for this transaction. [no locking] */
434
        journal_t               *t_journal;
435
 
436
        /* Sequence number for this transaction [no locking] */
437
        tid_t                   t_tid;
438
 
439
        /*
440
         * Transaction's current state
441
         * [no locking - only kjournald alters this]
442
         * [j_list_lock] guards transition of a transaction into T_FINISHED
443
         * state and subsequent call of __journal_drop_transaction()
444
         * FIXME: needs barriers
445
         * KLUDGE: [use j_state_lock]
446
         */
447
        enum {
448
                T_RUNNING,
449
                T_LOCKED,
450
                T_RUNDOWN,
451
                T_FLUSH,
452
                T_COMMIT,
453
                T_FINISHED
454
        }                       t_state;
455
 
456
        /*
457
         * Where in the log does this transaction's commit start? [no locking]
458
         */
459
        unsigned long           t_log_start;
460
 
461
        /* Number of buffers on the t_buffers list [j_list_lock] */
462
        int                     t_nr_buffers;
463
 
464
        /*
465
         * Doubly-linked circular list of all buffers reserved but not yet
466
         * modified by this transaction [j_list_lock]
467
         */
468
        struct journal_head     *t_reserved_list;
469
 
470
        /*
471
         * Doubly-linked circular list of all buffers under writeout during
472
         * commit [j_list_lock]
473
         */
474
        struct journal_head     *t_locked_list;
475
 
476
        /*
477
         * Doubly-linked circular list of all metadata buffers owned by this
478
         * transaction [j_list_lock]
479
         */
480
        struct journal_head     *t_buffers;
481
 
482
        /*
483
         * Doubly-linked circular list of all data buffers still to be
484
         * flushed before this transaction can be committed [j_list_lock]
485
         */
486
        struct journal_head     *t_sync_datalist;
487
 
488
        /*
489
         * Doubly-linked circular list of all forget buffers (superseded
490
         * buffers which we can un-checkpoint once this transaction commits)
491
         * [j_list_lock]
492
         */
493
        struct journal_head     *t_forget;
494
 
495
        /*
496
         * Doubly-linked circular list of all buffers still to be flushed before
497
         * this transaction can be checkpointed. [j_list_lock]
498
         */
499
        struct journal_head     *t_checkpoint_list;
500
 
501
        /*
502
         * Doubly-linked circular list of all buffers submitted for IO while
503
         * checkpointing. [j_list_lock]
504
         */
505
        struct journal_head     *t_checkpoint_io_list;
506
 
507
        /*
508
         * Doubly-linked circular list of temporary buffers currently undergoing
509
         * IO in the log [j_list_lock]
510
         */
511
        struct journal_head     *t_iobuf_list;
512
 
513
        /*
514
         * Doubly-linked circular list of metadata buffers being shadowed by log
515
         * IO.  The IO buffers on the iobuf list and the shadow buffers on this
516
         * list match each other one for one at all times. [j_list_lock]
517
         */
518
        struct journal_head     *t_shadow_list;
519
 
520
        /*
521
         * Doubly-linked circular list of control buffers being written to the
522
         * log. [j_list_lock]
523
         */
524
        struct journal_head     *t_log_list;
525
 
526
        /*
527
         * Protects info related to handles
528
         */
529
        spinlock_t              t_handle_lock;
530
 
531
        /*
532
         * Number of outstanding updates running on this transaction
533
         * [t_handle_lock]
534
         */
535
        int                     t_updates;
536
 
537
        /*
538
         * Number of buffers reserved for use by all handles in this transaction
539
         * handle but not yet modified. [t_handle_lock]
540
         */
541
        int                     t_outstanding_credits;
542
 
543
        /*
544
         * Forward and backward links for the circular list of all transactions
545
         * awaiting checkpoint. [j_list_lock]
546
         */
547
        transaction_t           *t_cpnext, *t_cpprev;
548
 
549
        /*
550
         * When will the transaction expire (become due for commit), in jiffies?
551
         * [no locking]
552
         */
553
        unsigned long           t_expires;
554
 
555
        /*
556
         * How many handles used this transaction? [t_handle_lock]
557
         */
558
        int t_handle_count;
559
 
560
};
561
 
562
/**
563
 * struct journal_s - The journal_s type is the concrete type associated with
564
 *     journal_t.
565
 * @j_flags:  General journaling state flags
566
 * @j_errno:  Is there an outstanding uncleared error on the journal (from a
567
 *     prior abort)?
568
 * @j_sb_buffer: First part of superblock buffer
569
 * @j_superblock: Second part of superblock buffer
570
 * @j_format_version: Version of the superblock format
571
 * @j_state_lock: Protect the various scalars in the journal
572
 * @j_barrier_count:  Number of processes waiting to create a barrier lock
573
 * @j_barrier: The barrier lock itself
574
 * @j_running_transaction: The current running transaction..
575
 * @j_committing_transaction: the transaction we are pushing to disk
576
 * @j_checkpoint_transactions: a linked circular list of all transactions
577
 *  waiting for checkpointing
578
 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
579
 *  to start committing, or for a barrier lock to be released
580
 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
581
 * @j_wait_done_commit: Wait queue for waiting for commit to complete
582
 * @j_wait_checkpoint:  Wait queue to trigger checkpointing
583
 * @j_wait_commit: Wait queue to trigger commit
584
 * @j_wait_updates: Wait queue to wait for updates to complete
585
 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
586
 * @j_head: Journal head - identifies the first unused block in the journal
587
 * @j_tail: Journal tail - identifies the oldest still-used block in the
588
 *  journal.
589
 * @j_free: Journal free - how many free blocks are there in the journal?
590
 * @j_first: The block number of the first usable block
591
 * @j_last: The block number one beyond the last usable block
592
 * @j_dev: Device where we store the journal
593
 * @j_blocksize: blocksize for the location where we store the journal.
594
 * @j_blk_offset: starting block offset for into the device where we store the
595
 *     journal
596
 * @j_fs_dev: Device which holds the client fs.  For internal journal this will
597
 *     be equal to j_dev
598
 * @j_maxlen: Total maximum capacity of the journal region on disk.
599
 * @j_list_lock: Protects the buffer lists and internal buffer state.
600
 * @j_inode: Optional inode where we store the journal.  If present, all journal
601
 *     block numbers are mapped into this inode via bmap().
602
 * @j_tail_sequence:  Sequence number of the oldest transaction in the log
603
 * @j_transaction_sequence: Sequence number of the next transaction to grant
604
 * @j_commit_sequence: Sequence number of the most recently committed
605
 *  transaction
606
 * @j_commit_request: Sequence number of the most recent transaction wanting
607
 *     commit
608
 * @j_uuid: Uuid of client object.
609
 * @j_task: Pointer to the current commit thread for this journal
610
 * @j_max_transaction_buffers:  Maximum number of metadata buffers to allow in a
611
 *     single compound commit transaction
612
 * @j_commit_interval: What is the maximum transaction lifetime before we begin
613
 *  a commit?
614
 * @j_commit_timer:  The timer used to wakeup the commit thread
615
 * @j_revoke_lock: Protect the revoke table
616
 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
617
 *     current transaction.
618
 * @j_revoke_table: alternate revoke tables for j_revoke
619
 * @j_wbuf: array of buffer_heads for journal_commit_transaction
620
 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
621
 *      number that will fit in j_blocksize
622
 * @j_last_sync_writer: most recent pid which did a synchronous write
623
 * @j_private: An opaque pointer to fs-private information.
624
 */
625
 
626
struct journal_s
627
{
628
        /* General journaling state flags [j_state_lock] */
629
        unsigned long           j_flags;
630
 
631
        /*
632
         * Is there an outstanding uncleared error on the journal (from a prior
633
         * abort)? [j_state_lock]
634
         */
635
        int                     j_errno;
636
 
637
        /* The superblock buffer */
638
        struct buffer_head      *j_sb_buffer;
639
        journal_superblock_t    *j_superblock;
640
 
641
        /* Version of the superblock format */
642
        int                     j_format_version;
643
 
644
        /*
645
         * Protect the various scalars in the journal
646
         */
647
        spinlock_t              j_state_lock;
648
 
649
        /*
650
         * Number of processes waiting to create a barrier lock [j_state_lock]
651
         */
652
        int                     j_barrier_count;
653
 
654
        /* The barrier lock itself */
655
        struct mutex            j_barrier;
656
 
657
        /*
658
         * Transactions: The current running transaction...
659
         * [j_state_lock] [caller holding open handle]
660
         */
661
        transaction_t           *j_running_transaction;
662
 
663
        /*
664
         * the transaction we are pushing to disk
665
         * [j_state_lock] [caller holding open handle]
666
         */
667
        transaction_t           *j_committing_transaction;
668
 
669
        /*
670
         * ... and a linked circular list of all transactions waiting for
671
         * checkpointing. [j_list_lock]
672
         */
673
        transaction_t           *j_checkpoint_transactions;
674
 
675
        /*
676
         * Wait queue for waiting for a locked transaction to start committing,
677
         * or for a barrier lock to be released
678
         */
679
        wait_queue_head_t       j_wait_transaction_locked;
680
 
681
        /* Wait queue for waiting for checkpointing to complete */
682
        wait_queue_head_t       j_wait_logspace;
683
 
684
        /* Wait queue for waiting for commit to complete */
685
        wait_queue_head_t       j_wait_done_commit;
686
 
687
        /* Wait queue to trigger checkpointing */
688
        wait_queue_head_t       j_wait_checkpoint;
689
 
690
        /* Wait queue to trigger commit */
691
        wait_queue_head_t       j_wait_commit;
692
 
693
        /* Wait queue to wait for updates to complete */
694
        wait_queue_head_t       j_wait_updates;
695
 
696
        /* Semaphore for locking against concurrent checkpoints */
697
        struct mutex            j_checkpoint_mutex;
698
 
699
        /*
700
         * Journal head: identifies the first unused block in the journal.
701
         * [j_state_lock]
702
         */
703
        unsigned long           j_head;
704
 
705
        /*
706
         * Journal tail: identifies the oldest still-used block in the journal.
707
         * [j_state_lock]
708
         */
709
        unsigned long           j_tail;
710
 
711
        /*
712
         * Journal free: how many free blocks are there in the journal?
713
         * [j_state_lock]
714
         */
715
        unsigned long           j_free;
716
 
717
        /*
718
         * Journal start and end: the block numbers of the first usable block
719
         * and one beyond the last usable block in the journal. [j_state_lock]
720
         */
721
        unsigned long           j_first;
722
        unsigned long           j_last;
723
 
724
        /*
725
         * Device, blocksize and starting block offset for the location where we
726
         * store the journal.
727
         */
728
        struct block_device     *j_dev;
729
        int                     j_blocksize;
730
        unsigned long           j_blk_offset;
731
 
732
        /*
733
         * Device which holds the client fs.  For internal journal this will be
734
         * equal to j_dev.
735
         */
736
        struct block_device     *j_fs_dev;
737
 
738
        /* Total maximum capacity of the journal region on disk. */
739
        unsigned int            j_maxlen;
740
 
741
        /*
742
         * Protects the buffer lists and internal buffer state.
743
         */
744
        spinlock_t              j_list_lock;
745
 
746
        /* Optional inode where we store the journal.  If present, all */
747
        /* journal block numbers are mapped into this inode via */
748
        /* bmap(). */
749
        struct inode            *j_inode;
750
 
751
        /*
752
         * Sequence number of the oldest transaction in the log [j_state_lock]
753
         */
754
        tid_t                   j_tail_sequence;
755
 
756
        /*
757
         * Sequence number of the next transaction to grant [j_state_lock]
758
         */
759
        tid_t                   j_transaction_sequence;
760
 
761
        /*
762
         * Sequence number of the most recently committed transaction
763
         * [j_state_lock].
764
         */
765
        tid_t                   j_commit_sequence;
766
 
767
        /*
768
         * Sequence number of the most recent transaction wanting commit
769
         * [j_state_lock]
770
         */
771
        tid_t                   j_commit_request;
772
 
773
        /*
774
         * Journal uuid: identifies the object (filesystem, LVM volume etc)
775
         * backed by this journal.  This will eventually be replaced by an array
776
         * of uuids, allowing us to index multiple devices within a single
777
         * journal and to perform atomic updates across them.
778
         */
779
        __u8                    j_uuid[16];
780
 
781
        /* Pointer to the current commit thread for this journal */
782
        struct task_struct      *j_task;
783
 
784
        /*
785
         * Maximum number of metadata buffers to allow in a single compound
786
         * commit transaction
787
         */
788
        int                     j_max_transaction_buffers;
789
 
790
        /*
791
         * What is the maximum transaction lifetime before we begin a commit?
792
         */
793
        unsigned long           j_commit_interval;
794
 
795
        /* The timer used to wakeup the commit thread: */
796
        struct timer_list       j_commit_timer;
797
 
798
        /*
799
         * The revoke table: maintains the list of revoked blocks in the
800
         * current transaction.  [j_revoke_lock]
801
         */
802
        spinlock_t              j_revoke_lock;
803
        struct jbd_revoke_table_s *j_revoke;
804
        struct jbd_revoke_table_s *j_revoke_table[2];
805
 
806
        /*
807
         * array of bhs for journal_commit_transaction
808
         */
809
        struct buffer_head      **j_wbuf;
810
        int                     j_wbufsize;
811
 
812
        pid_t                   j_last_sync_writer;
813
 
814
        /*
815
         * An opaque pointer to fs-private information.  ext3 puts its
816
         * superblock pointer here
817
         */
818
        void *j_private;
819
};
820
 
821
/*
822
 * Journal flag definitions
823
 */
824
#define JFS_UNMOUNT     0x001   /* Journal thread is being destroyed */
825
#define JFS_ABORT       0x002   /* Journaling has been aborted for errors. */
826
#define JFS_ACK_ERR     0x004   /* The errno in the sb has been acked */
827
#define JFS_FLUSHED     0x008   /* The journal superblock has been flushed */
828
#define JFS_LOADED      0x010   /* The journal superblock has been loaded */
829
#define JFS_BARRIER     0x020   /* Use IDE barriers */
830
 
831
/*
832
 * Function declarations for the journaling transaction and buffer
833
 * management
834
 */
835
 
836
/* Filing buffers */
837
extern void journal_unfile_buffer(journal_t *, struct journal_head *);
838
extern void __journal_unfile_buffer(struct journal_head *);
839
extern void __journal_refile_buffer(struct journal_head *);
840
extern void journal_refile_buffer(journal_t *, struct journal_head *);
841
extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
842
extern void __journal_free_buffer(struct journal_head *bh);
843
extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
844
extern void __journal_clean_data_list(transaction_t *transaction);
845
 
846
/* Log buffer allocation */
847
extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
848
int journal_next_log_block(journal_t *, unsigned long *);
849
 
850
/* Commit management */
851
extern void journal_commit_transaction(journal_t *);
852
 
853
/* Checkpoint list management */
854
int __journal_clean_checkpoint_list(journal_t *journal);
855
int __journal_remove_checkpoint(struct journal_head *);
856
void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
857
 
858
/* Buffer IO */
859
extern int
860
journal_write_metadata_buffer(transaction_t       *transaction,
861
                              struct journal_head  *jh_in,
862
                              struct journal_head **jh_out,
863
                              unsigned long        blocknr);
864
 
865
/* Transaction locking */
866
extern void             __wait_on_journal (journal_t *);
867
 
868
/*
869
 * Journal locking.
870
 *
871
 * We need to lock the journal during transaction state changes so that nobody
872
 * ever tries to take a handle on the running transaction while we are in the
873
 * middle of moving it to the commit phase.  j_state_lock does this.
874
 *
875
 * Note that the locking is completely interrupt unsafe.  We never touch
876
 * journal structures from interrupts.
877
 */
878
 
879
static inline handle_t *journal_current_handle(void)
880
{
881
        return current->journal_info;
882
}
883
 
884
/* The journaling code user interface:
885
 *
886
 * Create and destroy handles
887
 * Register buffer modifications against the current transaction.
888
 */
889
 
890
extern handle_t *journal_start(journal_t *, int nblocks);
891
extern int       journal_restart (handle_t *, int nblocks);
892
extern int       journal_extend (handle_t *, int nblocks);
893
extern int       journal_get_write_access(handle_t *, struct buffer_head *);
894
extern int       journal_get_create_access (handle_t *, struct buffer_head *);
895
extern int       journal_get_undo_access(handle_t *, struct buffer_head *);
896
extern int       journal_dirty_data (handle_t *, struct buffer_head *);
897
extern int       journal_dirty_metadata (handle_t *, struct buffer_head *);
898
extern void      journal_release_buffer (handle_t *, struct buffer_head *);
899
extern int       journal_forget (handle_t *, struct buffer_head *);
900
extern void      journal_sync_buffer (struct buffer_head *);
901
extern void      journal_invalidatepage(journal_t *,
902
                                struct page *, unsigned long);
903
extern int       journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
904
extern int       journal_stop(handle_t *);
905
extern int       journal_flush (journal_t *);
906
extern void      journal_lock_updates (journal_t *);
907
extern void      journal_unlock_updates (journal_t *);
908
 
909
extern journal_t * journal_init_dev(struct block_device *bdev,
910
                                struct block_device *fs_dev,
911
                                int start, int len, int bsize);
912
extern journal_t * journal_init_inode (struct inode *);
913
extern int         journal_update_format (journal_t *);
914
extern int         journal_check_used_features
915
                   (journal_t *, unsigned long, unsigned long, unsigned long);
916
extern int         journal_check_available_features
917
                   (journal_t *, unsigned long, unsigned long, unsigned long);
918
extern int         journal_set_features
919
                   (journal_t *, unsigned long, unsigned long, unsigned long);
920
extern int         journal_create     (journal_t *);
921
extern int         journal_load       (journal_t *journal);
922
extern void        journal_destroy    (journal_t *);
923
extern int         journal_recover    (journal_t *journal);
924
extern int         journal_wipe       (journal_t *, int);
925
extern int         journal_skip_recovery        (journal_t *);
926
extern void        journal_update_superblock    (journal_t *, int);
927
extern void        __journal_abort_hard (journal_t *);
928
extern void        journal_abort      (journal_t *, int);
929
extern int         journal_errno      (journal_t *);
930
extern void        journal_ack_err    (journal_t *);
931
extern int         journal_clear_err  (journal_t *);
932
extern int         journal_bmap(journal_t *, unsigned long, unsigned long *);
933
extern int         journal_force_commit(journal_t *);
934
 
935
/*
936
 * journal_head management
937
 */
938
struct journal_head *journal_add_journal_head(struct buffer_head *bh);
939
struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
940
void journal_remove_journal_head(struct buffer_head *bh);
941
void journal_put_journal_head(struct journal_head *jh);
942
 
943
/*
944
 * handle management
945
 */
946
extern struct kmem_cache *jbd_handle_cache;
947
 
948
static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
949
{
950
        return kmem_cache_alloc(jbd_handle_cache, gfp_flags);
951
}
952
 
953
static inline void jbd_free_handle(handle_t *handle)
954
{
955
        kmem_cache_free(jbd_handle_cache, handle);
956
}
957
 
958
/* Primary revoke support */
959
#define JOURNAL_REVOKE_DEFAULT_HASH 256
960
extern int         journal_init_revoke(journal_t *, int);
961
extern void        journal_destroy_revoke_caches(void);
962
extern int         journal_init_revoke_caches(void);
963
 
964
extern void        journal_destroy_revoke(journal_t *);
965
extern int         journal_revoke (handle_t *,
966
                                unsigned long, struct buffer_head *);
967
extern int         journal_cancel_revoke(handle_t *, struct journal_head *);
968
extern void        journal_write_revoke_records(journal_t *, transaction_t *);
969
 
970
/* Recovery revoke support */
971
extern int      journal_set_revoke(journal_t *, unsigned long, tid_t);
972
extern int      journal_test_revoke(journal_t *, unsigned long, tid_t);
973
extern void     journal_clear_revoke(journal_t *);
974
extern void     journal_switch_revoke_table(journal_t *journal);
975
 
976
/*
977
 * The log thread user interface:
978
 *
979
 * Request space in the current transaction, and force transaction commit
980
 * transitions on demand.
981
 */
982
 
983
int __log_space_left(journal_t *); /* Called with journal locked */
984
int log_start_commit(journal_t *journal, tid_t tid);
985
int __log_start_commit(journal_t *journal, tid_t tid);
986
int journal_start_commit(journal_t *journal, tid_t *tid);
987
int journal_force_commit_nested(journal_t *journal);
988
int log_wait_commit(journal_t *journal, tid_t tid);
989
int log_do_checkpoint(journal_t *journal);
990
 
991
void __log_wait_for_space(journal_t *journal);
992
extern void     __journal_drop_transaction(journal_t *, transaction_t *);
993
extern int      cleanup_journal_tail(journal_t *);
994
 
995
/* Debugging code only: */
996
 
997
#define jbd_ENOSYS() \
998
do {                                                                       \
999
        printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \
1000
        current->state = TASK_UNINTERRUPTIBLE;                             \
1001
        schedule();                                                        \
1002
} while (1)
1003
 
1004
/*
1005
 * is_journal_abort
1006
 *
1007
 * Simple test wrapper function to test the JFS_ABORT state flag.  This
1008
 * bit, when set, indicates that we have had a fatal error somewhere,
1009
 * either inside the journaling layer or indicated to us by the client
1010
 * (eg. ext3), and that we and should not commit any further
1011
 * transactions.
1012
 */
1013
 
1014
static inline int is_journal_aborted(journal_t *journal)
1015
{
1016
        return journal->j_flags & JFS_ABORT;
1017
}
1018
 
1019
static inline int is_handle_aborted(handle_t *handle)
1020
{
1021
        if (handle->h_aborted)
1022
                return 1;
1023
        return is_journal_aborted(handle->h_transaction->t_journal);
1024
}
1025
 
1026
static inline void journal_abort_handle(handle_t *handle)
1027
{
1028
        handle->h_aborted = 1;
1029
}
1030
 
1031
#endif /* __KERNEL__   */
1032
 
1033
/* Comparison functions for transaction IDs: perform comparisons using
1034
 * modulo arithmetic so that they work over sequence number wraps. */
1035
 
1036
static inline int tid_gt(tid_t x, tid_t y)
1037
{
1038
        int difference = (x - y);
1039
        return (difference > 0);
1040
}
1041
 
1042
static inline int tid_geq(tid_t x, tid_t y)
1043
{
1044
        int difference = (x - y);
1045
        return (difference >= 0);
1046
}
1047
 
1048
extern int journal_blocks_per_page(struct inode *inode);
1049
 
1050
/*
1051
 * Return the minimum number of blocks which must be free in the journal
1052
 * before a new transaction may be started.  Must be called under j_state_lock.
1053
 */
1054
static inline int jbd_space_needed(journal_t *journal)
1055
{
1056
        int nblocks = journal->j_max_transaction_buffers;
1057
        if (journal->j_committing_transaction)
1058
                nblocks += journal->j_committing_transaction->
1059
                                        t_outstanding_credits;
1060
        return nblocks;
1061
}
1062
 
1063
/*
1064
 * Definitions which augment the buffer_head layer
1065
 */
1066
 
1067
/* journaling buffer types */
1068
#define BJ_None         0        /* Not journaled */
1069
#define BJ_SyncData     1       /* Normal data: flush before commit */
1070
#define BJ_Metadata     2       /* Normal journaled metadata */
1071
#define BJ_Forget       3       /* Buffer superseded by this transaction */
1072
#define BJ_IO           4       /* Buffer is for temporary IO use */
1073
#define BJ_Shadow       5       /* Buffer contents being shadowed to the log */
1074
#define BJ_LogCtl       6       /* Buffer contains log descriptors */
1075
#define BJ_Reserved     7       /* Buffer is reserved for access by journal */
1076
#define BJ_Locked       8       /* Locked for I/O during commit */
1077
#define BJ_Types        9
1078
 
1079
extern int jbd_blocks_per_page(struct inode *inode);
1080
 
1081
#ifdef __KERNEL__
1082
 
1083
#define buffer_trace_init(bh)   do {} while (0)
1084
#define print_buffer_fields(bh) do {} while (0)
1085
#define print_buffer_trace(bh)  do {} while (0)
1086
#define BUFFER_TRACE(bh, info)  do {} while (0)
1087
#define BUFFER_TRACE2(bh, bh2, info)    do {} while (0)
1088
#define JBUFFER_TRACE(jh, info) do {} while (0)
1089
 
1090
#endif  /* __KERNEL__ */
1091
 
1092
#endif  /* _LINUX_JBD_H */

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