Branch data Line data Source code
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/types.h>
27 : : #include <linux/buffer_head.h>
28 : : #include <linux/journal-head.h>
29 : : #include <linux/stddef.h>
30 : : #include <linux/mutex.h>
31 : : #include <linux/timer.h>
32 : : #include <linux/lockdep.h>
33 : : #include <linux/slab.h>
34 : :
35 : : #define journal_oom_retry 1
36 : :
37 : : /*
38 : : * Define JBD_PARANOID_IOFAIL to cause a kernel BUG() if ext3 finds
39 : : * certain classes of error which can occur due to failed IOs. Under
40 : : * normal use we want ext3 to continue after such errors, because
41 : : * hardware _can_ fail, but for debugging purposes when running tests on
42 : : * known-good hardware we may want to trap these errors.
43 : : */
44 : : #undef JBD_PARANOID_IOFAIL
45 : :
46 : : /*
47 : : * The default maximum commit age, in seconds.
48 : : */
49 : : #define JBD_DEFAULT_MAX_COMMIT_AGE 5
50 : :
51 : : #ifdef CONFIG_JBD_DEBUG
52 : : /*
53 : : * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
54 : : * consistency checks. By default we don't do this unless
55 : : * CONFIG_JBD_DEBUG is on.
56 : : */
57 : : #define JBD_EXPENSIVE_CHECKING
58 : : extern u8 journal_enable_debug;
59 : :
60 : : void __jbd_debug(int level, const char *file, const char *func,
61 : : unsigned int line, const char *fmt, ...);
62 : :
63 : : #define jbd_debug(n, fmt, a...) \
64 : : __jbd_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
65 : : #else
66 : : #define jbd_debug(n, fmt, a...) /**/
67 : : #endif
68 : :
69 : : static inline void *jbd_alloc(size_t size, gfp_t flags)
70 : : {
71 [ # # ][ # # ]: 0 : return (void *)__get_free_pages(flags, get_order(size));
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72 : : }
73 : :
74 : : static inline void jbd_free(void *ptr, size_t size)
75 : : {
76 [ # # ][ # # ]: 0 : free_pages((unsigned long)ptr, get_order(size));
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77 : : }
78 : :
79 : : #define JFS_MIN_JOURNAL_BLOCKS 1024
80 : :
81 : :
82 : : /**
83 : : * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
84 : : *
85 : : * All filesystem modifications made by the process go
86 : : * through this handle. Recursive operations (such as quota operations)
87 : : * are gathered into a single update.
88 : : *
89 : : * The buffer credits field is used to account for journaled buffers
90 : : * being modified by the running process. To ensure that there is
91 : : * enough log space for all outstanding operations, we need to limit the
92 : : * number of outstanding buffers possible at any time. When the
93 : : * operation completes, any buffer credits not used are credited back to
94 : : * the transaction, so that at all times we know how many buffers the
95 : : * outstanding updates on a transaction might possibly touch.
96 : : *
97 : : * This is an opaque datatype.
98 : : **/
99 : : typedef struct handle_s handle_t; /* Atomic operation type */
100 : :
101 : :
102 : : /**
103 : : * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
104 : : *
105 : : * journal_t is linked to from the fs superblock structure.
106 : : *
107 : : * We use the journal_t to keep track of all outstanding transaction
108 : : * activity on the filesystem, and to manage the state of the log
109 : : * writing process.
110 : : *
111 : : * This is an opaque datatype.
112 : : **/
113 : : typedef struct journal_s journal_t; /* Journal control structure */
114 : : #endif
115 : :
116 : : /*
117 : : * Internal structures used by the logging mechanism:
118 : : */
119 : :
120 : : #define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
121 : :
122 : : /*
123 : : * On-disk structures
124 : : */
125 : :
126 : : /*
127 : : * Descriptor block types:
128 : : */
129 : :
130 : : #define JFS_DESCRIPTOR_BLOCK 1
131 : : #define JFS_COMMIT_BLOCK 2
132 : : #define JFS_SUPERBLOCK_V1 3
133 : : #define JFS_SUPERBLOCK_V2 4
134 : : #define JFS_REVOKE_BLOCK 5
135 : :
136 : : /*
137 : : * Standard header for all descriptor blocks:
138 : : */
139 : : typedef struct journal_header_s
140 : : {
141 : : __be32 h_magic;
142 : : __be32 h_blocktype;
143 : : __be32 h_sequence;
144 : : } journal_header_t;
145 : :
146 : :
147 : : /*
148 : : * The block tag: used to describe a single buffer in the journal
149 : : */
150 : : typedef struct journal_block_tag_s
151 : : {
152 : : __be32 t_blocknr; /* The on-disk block number */
153 : : __be32 t_flags; /* See below */
154 : : } journal_block_tag_t;
155 : :
156 : : /*
157 : : * The revoke descriptor: used on disk to describe a series of blocks to
158 : : * be revoked from the log
159 : : */
160 : : typedef struct journal_revoke_header_s
161 : : {
162 : : journal_header_t r_header;
163 : : __be32 r_count; /* Count of bytes used in the block */
164 : : } journal_revoke_header_t;
165 : :
166 : :
167 : : /* Definitions for the journal tag flags word: */
168 : : #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
169 : : #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
170 : : #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
171 : : #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
172 : :
173 : :
174 : : /*
175 : : * The journal superblock. All fields are in big-endian byte order.
176 : : */
177 : : typedef struct journal_superblock_s
178 : : {
179 : : /* 0x0000 */
180 : : journal_header_t s_header;
181 : :
182 : : /* 0x000C */
183 : : /* Static information describing the journal */
184 : : __be32 s_blocksize; /* journal device blocksize */
185 : : __be32 s_maxlen; /* total blocks in journal file */
186 : : __be32 s_first; /* first block of log information */
187 : :
188 : : /* 0x0018 */
189 : : /* Dynamic information describing the current state of the log */
190 : : __be32 s_sequence; /* first commit ID expected in log */
191 : : __be32 s_start; /* blocknr of start of log */
192 : :
193 : : /* 0x0020 */
194 : : /* Error value, as set by journal_abort(). */
195 : : __be32 s_errno;
196 : :
197 : : /* 0x0024 */
198 : : /* Remaining fields are only valid in a version-2 superblock */
199 : : __be32 s_feature_compat; /* compatible feature set */
200 : : __be32 s_feature_incompat; /* incompatible feature set */
201 : : __be32 s_feature_ro_compat; /* readonly-compatible feature set */
202 : : /* 0x0030 */
203 : : __u8 s_uuid[16]; /* 128-bit uuid for journal */
204 : :
205 : : /* 0x0040 */
206 : : __be32 s_nr_users; /* Nr of filesystems sharing log */
207 : :
208 : : __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
209 : :
210 : : /* 0x0048 */
211 : : __be32 s_max_transaction; /* Limit of journal blocks per trans.*/
212 : : __be32 s_max_trans_data; /* Limit of data blocks per trans. */
213 : :
214 : : /* 0x0050 */
215 : : __u32 s_padding[44];
216 : :
217 : : /* 0x0100 */
218 : : __u8 s_users[16*48]; /* ids of all fs'es sharing the log */
219 : : /* 0x0400 */
220 : : } journal_superblock_t;
221 : :
222 : : #define JFS_HAS_COMPAT_FEATURE(j,mask) \
223 : : ((j)->j_format_version >= 2 && \
224 : : ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
225 : : #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
226 : : ((j)->j_format_version >= 2 && \
227 : : ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
228 : : #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
229 : : ((j)->j_format_version >= 2 && \
230 : : ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
231 : :
232 : : #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
233 : :
234 : : /* Features known to this kernel version: */
235 : : #define JFS_KNOWN_COMPAT_FEATURES 0
236 : : #define JFS_KNOWN_ROCOMPAT_FEATURES 0
237 : : #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
238 : :
239 : : #ifdef __KERNEL__
240 : :
241 : : #include <linux/fs.h>
242 : : #include <linux/sched.h>
243 : :
244 : : enum jbd_state_bits {
245 : : BH_JBD /* Has an attached ext3 journal_head */
246 : : = BH_PrivateStart,
247 : : BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
248 : : BH_Freed, /* Has been freed (truncated) */
249 : : BH_Revoked, /* Has been revoked from the log */
250 : : BH_RevokeValid, /* Revoked flag is valid */
251 : : BH_JBDDirty, /* Is dirty but journaled */
252 : : BH_State, /* Pins most journal_head state */
253 : : BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
254 : : BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */
255 : : BH_JBDPrivateStart, /* First bit available for private use by FS */
256 : : };
257 : :
258 : 0 : BUFFER_FNS(JBD, jbd)
259 : 0 : BUFFER_FNS(JWrite, jwrite)
260 : 0 : BUFFER_FNS(JBDDirty, jbddirty)
261 : 0 : TAS_BUFFER_FNS(JBDDirty, jbddirty)
262 : 0 : BUFFER_FNS(Revoked, revoked)
263 : 0 : TAS_BUFFER_FNS(Revoked, revoked)
264 : 0 : BUFFER_FNS(RevokeValid, revokevalid)
265 : 0 : TAS_BUFFER_FNS(RevokeValid, revokevalid)
266 : 0 : BUFFER_FNS(Freed, freed)
267 : :
268 : : #include <linux/jbd_common.h>
269 : :
270 : : #define J_ASSERT(assert) BUG_ON(!(assert))
271 : :
272 : : #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
273 : : #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
274 : :
275 : : #if defined(JBD_PARANOID_IOFAIL)
276 : : #define J_EXPECT(expr, why...) J_ASSERT(expr)
277 : : #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
278 : : #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
279 : : #else
280 : : #define __journal_expect(expr, why...) \
281 : : ({ \
282 : : int val = (expr); \
283 : : if (!val) { \
284 : : printk(KERN_ERR \
285 : : "EXT3-fs unexpected failure: %s;\n",# expr); \
286 : : printk(KERN_ERR why "\n"); \
287 : : } \
288 : : val; \
289 : : })
290 : : #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
291 : : #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
292 : : #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
293 : : #endif
294 : :
295 : : struct jbd_revoke_table_s;
296 : :
297 : : /**
298 : : * struct handle_s - this is the concrete type associated with handle_t.
299 : : * @h_transaction: Which compound transaction is this update a part of?
300 : : * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
301 : : * @h_ref: Reference count on this handle
302 : : * @h_err: Field for caller's use to track errors through large fs operations
303 : : * @h_sync: flag for sync-on-close
304 : : * @h_jdata: flag to force data journaling
305 : : * @h_aborted: flag indicating fatal error on handle
306 : : * @h_lockdep_map: lockdep info for debugging lock problems
307 : : */
308 : : struct handle_s
309 : : {
310 : : /* Which compound transaction is this update a part of? */
311 : : transaction_t *h_transaction;
312 : :
313 : : /* Number of remaining buffers we are allowed to dirty: */
314 : : int h_buffer_credits;
315 : :
316 : : /* Reference count on this handle */
317 : : int h_ref;
318 : :
319 : : /* Field for caller's use to track errors through large fs */
320 : : /* operations */
321 : : int h_err;
322 : :
323 : : /* Flags [no locking] */
324 : : unsigned int h_sync: 1; /* sync-on-close */
325 : : unsigned int h_jdata: 1; /* force data journaling */
326 : : unsigned int h_aborted: 1; /* fatal error on handle */
327 : :
328 : : #ifdef CONFIG_DEBUG_LOCK_ALLOC
329 : : struct lockdep_map h_lockdep_map;
330 : : #endif
331 : : };
332 : :
333 : :
334 : : /* The transaction_t type is the guts of the journaling mechanism. It
335 : : * tracks a compound transaction through its various states:
336 : : *
337 : : * RUNNING: accepting new updates
338 : : * LOCKED: Updates still running but we don't accept new ones
339 : : * RUNDOWN: Updates are tidying up but have finished requesting
340 : : * new buffers to modify (state not used for now)
341 : : * FLUSH: All updates complete, but we are still writing to disk
342 : : * COMMIT: All data on disk, writing commit record
343 : : * FINISHED: We still have to keep the transaction for checkpointing.
344 : : *
345 : : * The transaction keeps track of all of the buffers modified by a
346 : : * running transaction, and all of the buffers committed but not yet
347 : : * flushed to home for finished transactions.
348 : : */
349 : :
350 : : /*
351 : : * Lock ranking:
352 : : *
353 : : * j_list_lock
354 : : * ->jbd_lock_bh_journal_head() (This is "innermost")
355 : : *
356 : : * j_state_lock
357 : : * ->jbd_lock_bh_state()
358 : : *
359 : : * jbd_lock_bh_state()
360 : : * ->j_list_lock
361 : : *
362 : : * j_state_lock
363 : : * ->t_handle_lock
364 : : *
365 : : * j_state_lock
366 : : * ->j_list_lock (journal_unmap_buffer)
367 : : *
368 : : */
369 : :
370 : : struct transaction_s
371 : : {
372 : : /* Pointer to the journal for this transaction. [no locking] */
373 : : journal_t *t_journal;
374 : :
375 : : /* Sequence number for this transaction [no locking] */
376 : : tid_t t_tid;
377 : :
378 : : /*
379 : : * Transaction's current state
380 : : * [no locking - only kjournald alters this]
381 : : * [j_list_lock] guards transition of a transaction into T_FINISHED
382 : : * state and subsequent call of __journal_drop_transaction()
383 : : * FIXME: needs barriers
384 : : * KLUDGE: [use j_state_lock]
385 : : */
386 : : enum {
387 : : T_RUNNING,
388 : : T_LOCKED,
389 : : T_FLUSH,
390 : : T_COMMIT,
391 : : T_COMMIT_RECORD,
392 : : T_FINISHED
393 : : } t_state;
394 : :
395 : : /*
396 : : * Where in the log does this transaction's commit start? [no locking]
397 : : */
398 : : unsigned int t_log_start;
399 : :
400 : : /* Number of buffers on the t_buffers list [j_list_lock] */
401 : : int t_nr_buffers;
402 : :
403 : : /*
404 : : * Doubly-linked circular list of all buffers reserved but not yet
405 : : * modified by this transaction [j_list_lock]
406 : : */
407 : : struct journal_head *t_reserved_list;
408 : :
409 : : /*
410 : : * Doubly-linked circular list of all buffers under writeout during
411 : : * commit [j_list_lock]
412 : : */
413 : : struct journal_head *t_locked_list;
414 : :
415 : : /*
416 : : * Doubly-linked circular list of all metadata buffers owned by this
417 : : * transaction [j_list_lock]
418 : : */
419 : : struct journal_head *t_buffers;
420 : :
421 : : /*
422 : : * Doubly-linked circular list of all data buffers still to be
423 : : * flushed before this transaction can be committed [j_list_lock]
424 : : */
425 : : struct journal_head *t_sync_datalist;
426 : :
427 : : /*
428 : : * Doubly-linked circular list of all forget buffers (superseded
429 : : * buffers which we can un-checkpoint once this transaction commits)
430 : : * [j_list_lock]
431 : : */
432 : : struct journal_head *t_forget;
433 : :
434 : : /*
435 : : * Doubly-linked circular list of all buffers still to be flushed before
436 : : * this transaction can be checkpointed. [j_list_lock]
437 : : */
438 : : struct journal_head *t_checkpoint_list;
439 : :
440 : : /*
441 : : * Doubly-linked circular list of all buffers submitted for IO while
442 : : * checkpointing. [j_list_lock]
443 : : */
444 : : struct journal_head *t_checkpoint_io_list;
445 : :
446 : : /*
447 : : * Doubly-linked circular list of temporary buffers currently undergoing
448 : : * IO in the log [j_list_lock]
449 : : */
450 : : struct journal_head *t_iobuf_list;
451 : :
452 : : /*
453 : : * Doubly-linked circular list of metadata buffers being shadowed by log
454 : : * IO. The IO buffers on the iobuf list and the shadow buffers on this
455 : : * list match each other one for one at all times. [j_list_lock]
456 : : */
457 : : struct journal_head *t_shadow_list;
458 : :
459 : : /*
460 : : * Doubly-linked circular list of control buffers being written to the
461 : : * log. [j_list_lock]
462 : : */
463 : : struct journal_head *t_log_list;
464 : :
465 : : /*
466 : : * Protects info related to handles
467 : : */
468 : : spinlock_t t_handle_lock;
469 : :
470 : : /*
471 : : * Number of outstanding updates running on this transaction
472 : : * [t_handle_lock]
473 : : */
474 : : int t_updates;
475 : :
476 : : /*
477 : : * Number of buffers reserved for use by all handles in this transaction
478 : : * handle but not yet modified. [t_handle_lock]
479 : : */
480 : : int t_outstanding_credits;
481 : :
482 : : /*
483 : : * Forward and backward links for the circular list of all transactions
484 : : * awaiting checkpoint. [j_list_lock]
485 : : */
486 : : transaction_t *t_cpnext, *t_cpprev;
487 : :
488 : : /*
489 : : * When will the transaction expire (become due for commit), in jiffies?
490 : : * [no locking]
491 : : */
492 : : unsigned long t_expires;
493 : :
494 : : /*
495 : : * When this transaction started, in nanoseconds [no locking]
496 : : */
497 : : ktime_t t_start_time;
498 : :
499 : : /*
500 : : * How many handles used this transaction? [t_handle_lock]
501 : : */
502 : : int t_handle_count;
503 : : };
504 : :
505 : : /**
506 : : * struct journal_s - this is the concrete type associated with journal_t.
507 : : * @j_flags: General journaling state flags
508 : : * @j_errno: Is there an outstanding uncleared error on the journal (from a
509 : : * prior abort)?
510 : : * @j_sb_buffer: First part of superblock buffer
511 : : * @j_superblock: Second part of superblock buffer
512 : : * @j_format_version: Version of the superblock format
513 : : * @j_state_lock: Protect the various scalars in the journal
514 : : * @j_barrier_count: Number of processes waiting to create a barrier lock
515 : : * @j_running_transaction: The current running transaction..
516 : : * @j_committing_transaction: the transaction we are pushing to disk
517 : : * @j_checkpoint_transactions: a linked circular list of all transactions
518 : : * waiting for checkpointing
519 : : * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
520 : : * to start committing, or for a barrier lock to be released
521 : : * @j_wait_logspace: Wait queue for waiting for checkpointing to complete
522 : : * @j_wait_done_commit: Wait queue for waiting for commit to complete
523 : : * @j_wait_checkpoint: Wait queue to trigger checkpointing
524 : : * @j_wait_commit: Wait queue to trigger commit
525 : : * @j_wait_updates: Wait queue to wait for updates to complete
526 : : * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
527 : : * @j_head: Journal head - identifies the first unused block in the journal
528 : : * @j_tail: Journal tail - identifies the oldest still-used block in the
529 : : * journal.
530 : : * @j_free: Journal free - how many free blocks are there in the journal?
531 : : * @j_first: The block number of the first usable block
532 : : * @j_last: The block number one beyond the last usable block
533 : : * @j_dev: Device where we store the journal
534 : : * @j_blocksize: blocksize for the location where we store the journal.
535 : : * @j_blk_offset: starting block offset for into the device where we store the
536 : : * journal
537 : : * @j_fs_dev: Device which holds the client fs. For internal journal this will
538 : : * be equal to j_dev
539 : : * @j_maxlen: Total maximum capacity of the journal region on disk.
540 : : * @j_list_lock: Protects the buffer lists and internal buffer state.
541 : : * @j_inode: Optional inode where we store the journal. If present, all journal
542 : : * block numbers are mapped into this inode via bmap().
543 : : * @j_tail_sequence: Sequence number of the oldest transaction in the log
544 : : * @j_transaction_sequence: Sequence number of the next transaction to grant
545 : : * @j_commit_sequence: Sequence number of the most recently committed
546 : : * transaction
547 : : * @j_commit_request: Sequence number of the most recent transaction wanting
548 : : * commit
549 : : * @j_commit_waited: Sequence number of the most recent transaction someone
550 : : * is waiting for to commit.
551 : : * @j_uuid: Uuid of client object.
552 : : * @j_task: Pointer to the current commit thread for this journal
553 : : * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
554 : : * single compound commit transaction
555 : : * @j_commit_interval: What is the maximum transaction lifetime before we begin
556 : : * a commit?
557 : : * @j_commit_timer: The timer used to wakeup the commit thread
558 : : * @j_revoke_lock: Protect the revoke table
559 : : * @j_revoke: The revoke table - maintains the list of revoked blocks in the
560 : : * current transaction.
561 : : * @j_revoke_table: alternate revoke tables for j_revoke
562 : : * @j_wbuf: array of buffer_heads for journal_commit_transaction
563 : : * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
564 : : * number that will fit in j_blocksize
565 : : * @j_last_sync_writer: most recent pid which did a synchronous write
566 : : * @j_average_commit_time: the average amount of time in nanoseconds it
567 : : * takes to commit a transaction to the disk.
568 : : * @j_private: An opaque pointer to fs-private information.
569 : : */
570 : :
571 : : struct journal_s
572 : : {
573 : : /* General journaling state flags [j_state_lock] */
574 : : unsigned long j_flags;
575 : :
576 : : /*
577 : : * Is there an outstanding uncleared error on the journal (from a prior
578 : : * abort)? [j_state_lock]
579 : : */
580 : : int j_errno;
581 : :
582 : : /* The superblock buffer */
583 : : struct buffer_head *j_sb_buffer;
584 : : journal_superblock_t *j_superblock;
585 : :
586 : : /* Version of the superblock format */
587 : : int j_format_version;
588 : :
589 : : /*
590 : : * Protect the various scalars in the journal
591 : : */
592 : : spinlock_t j_state_lock;
593 : :
594 : : /*
595 : : * Number of processes waiting to create a barrier lock [j_state_lock]
596 : : */
597 : : int j_barrier_count;
598 : :
599 : : /*
600 : : * Transactions: The current running transaction...
601 : : * [j_state_lock] [caller holding open handle]
602 : : */
603 : : transaction_t *j_running_transaction;
604 : :
605 : : /*
606 : : * the transaction we are pushing to disk
607 : : * [j_state_lock] [caller holding open handle]
608 : : */
609 : : transaction_t *j_committing_transaction;
610 : :
611 : : /*
612 : : * ... and a linked circular list of all transactions waiting for
613 : : * checkpointing. [j_list_lock]
614 : : */
615 : : transaction_t *j_checkpoint_transactions;
616 : :
617 : : /*
618 : : * Wait queue for waiting for a locked transaction to start committing,
619 : : * or for a barrier lock to be released
620 : : */
621 : : wait_queue_head_t j_wait_transaction_locked;
622 : :
623 : : /* Wait queue for waiting for checkpointing to complete */
624 : : wait_queue_head_t j_wait_logspace;
625 : :
626 : : /* Wait queue for waiting for commit to complete */
627 : : wait_queue_head_t j_wait_done_commit;
628 : :
629 : : /* Wait queue to trigger checkpointing */
630 : : wait_queue_head_t j_wait_checkpoint;
631 : :
632 : : /* Wait queue to trigger commit */
633 : : wait_queue_head_t j_wait_commit;
634 : :
635 : : /* Wait queue to wait for updates to complete */
636 : : wait_queue_head_t j_wait_updates;
637 : :
638 : : /* Semaphore for locking against concurrent checkpoints */
639 : : struct mutex j_checkpoint_mutex;
640 : :
641 : : /*
642 : : * Journal head: identifies the first unused block in the journal.
643 : : * [j_state_lock]
644 : : */
645 : : unsigned int j_head;
646 : :
647 : : /*
648 : : * Journal tail: identifies the oldest still-used block in the journal.
649 : : * [j_state_lock]
650 : : */
651 : : unsigned int j_tail;
652 : :
653 : : /*
654 : : * Journal free: how many free blocks are there in the journal?
655 : : * [j_state_lock]
656 : : */
657 : : unsigned int j_free;
658 : :
659 : : /*
660 : : * Journal start and end: the block numbers of the first usable block
661 : : * and one beyond the last usable block in the journal. [j_state_lock]
662 : : */
663 : : unsigned int j_first;
664 : : unsigned int j_last;
665 : :
666 : : /*
667 : : * Device, blocksize and starting block offset for the location where we
668 : : * store the journal.
669 : : */
670 : : struct block_device *j_dev;
671 : : int j_blocksize;
672 : : unsigned int j_blk_offset;
673 : :
674 : : /*
675 : : * Device which holds the client fs. For internal journal this will be
676 : : * equal to j_dev.
677 : : */
678 : : struct block_device *j_fs_dev;
679 : :
680 : : /* Total maximum capacity of the journal region on disk. */
681 : : unsigned int j_maxlen;
682 : :
683 : : /*
684 : : * Protects the buffer lists and internal buffer state.
685 : : */
686 : : spinlock_t j_list_lock;
687 : :
688 : : /* Optional inode where we store the journal. If present, all */
689 : : /* journal block numbers are mapped into this inode via */
690 : : /* bmap(). */
691 : : struct inode *j_inode;
692 : :
693 : : /*
694 : : * Sequence number of the oldest transaction in the log [j_state_lock]
695 : : */
696 : : tid_t j_tail_sequence;
697 : :
698 : : /*
699 : : * Sequence number of the next transaction to grant [j_state_lock]
700 : : */
701 : : tid_t j_transaction_sequence;
702 : :
703 : : /*
704 : : * Sequence number of the most recently committed transaction
705 : : * [j_state_lock].
706 : : */
707 : : tid_t j_commit_sequence;
708 : :
709 : : /*
710 : : * Sequence number of the most recent transaction wanting commit
711 : : * [j_state_lock]
712 : : */
713 : : tid_t j_commit_request;
714 : :
715 : : /*
716 : : * Sequence number of the most recent transaction someone is waiting
717 : : * for to commit.
718 : : * [j_state_lock]
719 : : */
720 : : tid_t j_commit_waited;
721 : :
722 : : /*
723 : : * Journal uuid: identifies the object (filesystem, LVM volume etc)
724 : : * backed by this journal. This will eventually be replaced by an array
725 : : * of uuids, allowing us to index multiple devices within a single
726 : : * journal and to perform atomic updates across them.
727 : : */
728 : : __u8 j_uuid[16];
729 : :
730 : : /* Pointer to the current commit thread for this journal */
731 : : struct task_struct *j_task;
732 : :
733 : : /*
734 : : * Maximum number of metadata buffers to allow in a single compound
735 : : * commit transaction
736 : : */
737 : : int j_max_transaction_buffers;
738 : :
739 : : /*
740 : : * What is the maximum transaction lifetime before we begin a commit?
741 : : */
742 : : unsigned long j_commit_interval;
743 : :
744 : : /* The timer used to wakeup the commit thread: */
745 : : struct timer_list j_commit_timer;
746 : :
747 : : /*
748 : : * The revoke table: maintains the list of revoked blocks in the
749 : : * current transaction. [j_revoke_lock]
750 : : */
751 : : spinlock_t j_revoke_lock;
752 : : struct jbd_revoke_table_s *j_revoke;
753 : : struct jbd_revoke_table_s *j_revoke_table[2];
754 : :
755 : : /*
756 : : * array of bhs for journal_commit_transaction
757 : : */
758 : : struct buffer_head **j_wbuf;
759 : : int j_wbufsize;
760 : :
761 : : /*
762 : : * this is the pid of the last person to run a synchronous operation
763 : : * through the journal.
764 : : */
765 : : pid_t j_last_sync_writer;
766 : :
767 : : /*
768 : : * the average amount of time in nanoseconds it takes to commit a
769 : : * transaction to the disk. [j_state_lock]
770 : : */
771 : : u64 j_average_commit_time;
772 : :
773 : : /*
774 : : * An opaque pointer to fs-private information. ext3 puts its
775 : : * superblock pointer here
776 : : */
777 : : void *j_private;
778 : : };
779 : :
780 : : /*
781 : : * Journal flag definitions
782 : : */
783 : : #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
784 : : #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
785 : : #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
786 : : #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
787 : : #define JFS_LOADED 0x010 /* The journal superblock has been loaded */
788 : : #define JFS_BARRIER 0x020 /* Use IDE barriers */
789 : : #define JFS_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
790 : : * data write error in ordered
791 : : * mode */
792 : :
793 : : /*
794 : : * Function declarations for the journaling transaction and buffer
795 : : * management
796 : : */
797 : :
798 : : /* Filing buffers */
799 : : extern void journal_unfile_buffer(journal_t *, struct journal_head *);
800 : : extern void __journal_unfile_buffer(struct journal_head *);
801 : : extern void __journal_refile_buffer(struct journal_head *);
802 : : extern void journal_refile_buffer(journal_t *, struct journal_head *);
803 : : extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
804 : : extern void __journal_free_buffer(struct journal_head *bh);
805 : : extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
806 : : extern void __journal_clean_data_list(transaction_t *transaction);
807 : :
808 : : /* Log buffer allocation */
809 : : extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
810 : : int journal_next_log_block(journal_t *, unsigned int *);
811 : :
812 : : /* Commit management */
813 : : extern void journal_commit_transaction(journal_t *);
814 : :
815 : : /* Checkpoint list management */
816 : : int __journal_clean_checkpoint_list(journal_t *journal);
817 : : int __journal_remove_checkpoint(struct journal_head *);
818 : : void __journal_insert_checkpoint(struct journal_head *, transaction_t *);
819 : :
820 : : /* Buffer IO */
821 : : extern int
822 : : journal_write_metadata_buffer(transaction_t *transaction,
823 : : struct journal_head *jh_in,
824 : : struct journal_head **jh_out,
825 : : unsigned int blocknr);
826 : :
827 : : /* Transaction locking */
828 : : extern void __wait_on_journal (journal_t *);
829 : :
830 : : /*
831 : : * Journal locking.
832 : : *
833 : : * We need to lock the journal during transaction state changes so that nobody
834 : : * ever tries to take a handle on the running transaction while we are in the
835 : : * middle of moving it to the commit phase. j_state_lock does this.
836 : : *
837 : : * Note that the locking is completely interrupt unsafe. We never touch
838 : : * journal structures from interrupts.
839 : : */
840 : :
841 : : static inline handle_t *journal_current_handle(void)
842 : : {
843 : 0 : return current->journal_info;
844 : : }
845 : :
846 : : /* The journaling code user interface:
847 : : *
848 : : * Create and destroy handles
849 : : * Register buffer modifications against the current transaction.
850 : : */
851 : :
852 : : extern handle_t *journal_start(journal_t *, int nblocks);
853 : : extern int journal_restart (handle_t *, int nblocks);
854 : : extern int journal_extend (handle_t *, int nblocks);
855 : : extern int journal_get_write_access(handle_t *, struct buffer_head *);
856 : : extern int journal_get_create_access (handle_t *, struct buffer_head *);
857 : : extern int journal_get_undo_access(handle_t *, struct buffer_head *);
858 : : extern int journal_dirty_data (handle_t *, struct buffer_head *);
859 : : extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
860 : : extern void journal_release_buffer (handle_t *, struct buffer_head *);
861 : : extern int journal_forget (handle_t *, struct buffer_head *);
862 : : extern void journal_sync_buffer (struct buffer_head *);
863 : : extern void journal_invalidatepage(journal_t *,
864 : : struct page *, unsigned int, unsigned int);
865 : : extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
866 : : extern int journal_stop(handle_t *);
867 : : extern int journal_flush (journal_t *);
868 : : extern void journal_lock_updates (journal_t *);
869 : : extern void journal_unlock_updates (journal_t *);
870 : :
871 : : extern journal_t * journal_init_dev(struct block_device *bdev,
872 : : struct block_device *fs_dev,
873 : : int start, int len, int bsize);
874 : : extern journal_t * journal_init_inode (struct inode *);
875 : : extern int journal_update_format (journal_t *);
876 : : extern int journal_check_used_features
877 : : (journal_t *, unsigned long, unsigned long, unsigned long);
878 : : extern int journal_check_available_features
879 : : (journal_t *, unsigned long, unsigned long, unsigned long);
880 : : extern int journal_set_features
881 : : (journal_t *, unsigned long, unsigned long, unsigned long);
882 : : extern int journal_create (journal_t *);
883 : : extern int journal_load (journal_t *journal);
884 : : extern int journal_destroy (journal_t *);
885 : : extern int journal_recover (journal_t *journal);
886 : : extern int journal_wipe (journal_t *, int);
887 : : extern int journal_skip_recovery (journal_t *);
888 : : extern void journal_update_sb_log_tail (journal_t *, tid_t, unsigned int,
889 : : int);
890 : : extern void journal_abort (journal_t *, int);
891 : : extern int journal_errno (journal_t *);
892 : : extern void journal_ack_err (journal_t *);
893 : : extern int journal_clear_err (journal_t *);
894 : : extern int journal_bmap(journal_t *, unsigned int, unsigned int *);
895 : : extern int journal_force_commit(journal_t *);
896 : :
897 : : /*
898 : : * journal_head management
899 : : */
900 : : struct journal_head *journal_add_journal_head(struct buffer_head *bh);
901 : : struct journal_head *journal_grab_journal_head(struct buffer_head *bh);
902 : : void journal_put_journal_head(struct journal_head *jh);
903 : :
904 : : /*
905 : : * handle management
906 : : */
907 : : extern struct kmem_cache *jbd_handle_cache;
908 : :
909 : : static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
910 : : {
911 : 0 : return kmem_cache_zalloc(jbd_handle_cache, gfp_flags);
912 : : }
913 : :
914 : : static inline void jbd_free_handle(handle_t *handle)
915 : : {
916 : 0 : kmem_cache_free(jbd_handle_cache, handle);
917 : : }
918 : :
919 : : /* Primary revoke support */
920 : : #define JOURNAL_REVOKE_DEFAULT_HASH 256
921 : : extern int journal_init_revoke(journal_t *, int);
922 : : extern void journal_destroy_revoke_caches(void);
923 : : extern int journal_init_revoke_caches(void);
924 : :
925 : : extern void journal_destroy_revoke(journal_t *);
926 : : extern int journal_revoke (handle_t *,
927 : : unsigned int, struct buffer_head *);
928 : : extern int journal_cancel_revoke(handle_t *, struct journal_head *);
929 : : extern void journal_write_revoke_records(journal_t *,
930 : : transaction_t *, int);
931 : :
932 : : /* Recovery revoke support */
933 : : extern int journal_set_revoke(journal_t *, unsigned int, tid_t);
934 : : extern int journal_test_revoke(journal_t *, unsigned int, tid_t);
935 : : extern void journal_clear_revoke(journal_t *);
936 : : extern void journal_switch_revoke_table(journal_t *journal);
937 : : extern void journal_clear_buffer_revoked_flags(journal_t *journal);
938 : :
939 : : /*
940 : : * The log thread user interface:
941 : : *
942 : : * Request space in the current transaction, and force transaction commit
943 : : * transitions on demand.
944 : : */
945 : :
946 : : int __log_space_left(journal_t *); /* Called with journal locked */
947 : : int log_start_commit(journal_t *journal, tid_t tid);
948 : : int __log_start_commit(journal_t *journal, tid_t tid);
949 : : int journal_start_commit(journal_t *journal, tid_t *tid);
950 : : int journal_force_commit_nested(journal_t *journal);
951 : : int log_wait_commit(journal_t *journal, tid_t tid);
952 : : int log_do_checkpoint(journal_t *journal);
953 : : int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
954 : :
955 : : void __log_wait_for_space(journal_t *journal);
956 : : extern void __journal_drop_transaction(journal_t *, transaction_t *);
957 : : extern int cleanup_journal_tail(journal_t *);
958 : :
959 : : /* Debugging code only: */
960 : :
961 : : #define jbd_ENOSYS() \
962 : : do { \
963 : : printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \
964 : : current->state = TASK_UNINTERRUPTIBLE; \
965 : : schedule(); \
966 : : } while (1)
967 : :
968 : : /*
969 : : * is_journal_abort
970 : : *
971 : : * Simple test wrapper function to test the JFS_ABORT state flag. This
972 : : * bit, when set, indicates that we have had a fatal error somewhere,
973 : : * either inside the journaling layer or indicated to us by the client
974 : : * (eg. ext3), and that we and should not commit any further
975 : : * transactions.
976 : : */
977 : :
978 : : static inline int is_journal_aborted(journal_t *journal)
979 : : {
980 : 0 : return journal->j_flags & JFS_ABORT;
981 : : }
982 : :
983 : : static inline int is_handle_aborted(handle_t *handle)
984 : : {
985 [ # # ][ # # ]: 0 : if (handle->h_aborted)
[ # # # # ]
[ # # # # ]
[ # # ][ # # ]
[ # # ]
986 : : return 1;
987 : 0 : return is_journal_aborted(handle->h_transaction->t_journal);
988 : : }
989 : :
990 : : static inline void journal_abort_handle(handle_t *handle)
991 : : {
992 : 0 : handle->h_aborted = 1;
993 : : }
994 : :
995 : : #endif /* __KERNEL__ */
996 : :
997 : : /* Comparison functions for transaction IDs: perform comparisons using
998 : : * modulo arithmetic so that they work over sequence number wraps. */
999 : :
1000 : : static inline int tid_gt(tid_t x, tid_t y)
1001 : : {
1002 : 0 : int difference = (x - y);
1003 : : return (difference > 0);
1004 : : }
1005 : :
1006 : : static inline int tid_geq(tid_t x, tid_t y)
1007 : : {
1008 : 0 : int difference = (x - y);
1009 : : return (difference >= 0);
1010 : : }
1011 : :
1012 : : extern int journal_blocks_per_page(struct inode *inode);
1013 : :
1014 : : /*
1015 : : * Return the minimum number of blocks which must be free in the journal
1016 : : * before a new transaction may be started. Must be called under j_state_lock.
1017 : : */
1018 : : static inline int jbd_space_needed(journal_t *journal)
1019 : : {
1020 : : int nblocks = journal->j_max_transaction_buffers;
1021 [ # # ]: 0 : if (journal->j_committing_transaction)
[ # # # # ]
1022 : 0 : nblocks += journal->j_committing_transaction->
1023 : : t_outstanding_credits;
1024 : : return nblocks;
1025 : : }
1026 : :
1027 : : /*
1028 : : * Definitions which augment the buffer_head layer
1029 : : */
1030 : :
1031 : : /* journaling buffer types */
1032 : : #define BJ_None 0 /* Not journaled */
1033 : : #define BJ_SyncData 1 /* Normal data: flush before commit */
1034 : : #define BJ_Metadata 2 /* Normal journaled metadata */
1035 : : #define BJ_Forget 3 /* Buffer superseded by this transaction */
1036 : : #define BJ_IO 4 /* Buffer is for temporary IO use */
1037 : : #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */
1038 : : #define BJ_LogCtl 6 /* Buffer contains log descriptors */
1039 : : #define BJ_Reserved 7 /* Buffer is reserved for access by journal */
1040 : : #define BJ_Locked 8 /* Locked for I/O during commit */
1041 : : #define BJ_Types 9
1042 : :
1043 : : extern int jbd_blocks_per_page(struct inode *inode);
1044 : :
1045 : : #ifdef __KERNEL__
1046 : :
1047 : : #define buffer_trace_init(bh) do {} while (0)
1048 : : #define print_buffer_fields(bh) do {} while (0)
1049 : : #define print_buffer_trace(bh) do {} while (0)
1050 : : #define BUFFER_TRACE(bh, info) do {} while (0)
1051 : : #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1052 : : #define JBUFFER_TRACE(jh, info) do {} while (0)
1053 : :
1054 : : #endif /* __KERNEL__ */
1055 : :
1056 : : #endif /* _LINUX_JBD_H */
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