kernel-jbd.h revision dec5cd13fff821d1d3f6a922fbd986b3a86abb77
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#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__) 20 21/* Allow this file to be included directly into e2fsprogs */ 22#ifndef __KERNEL__ 23#include "jfs_compat.h" 24#define JFS_DEBUG 25#define jfs_debug jbd_debug 26#else 27 28#include <linux/journal-head.h> 29#include <linux/stddef.h> 30#include <asm/semaphore.h> 31#endif 32 33#ifndef __GNUC__ 34#define __FUNCTION__ "" 35#endif 36 37#define journal_oom_retry 1 38 39#ifdef __STDC__ 40#ifdef CONFIG_JBD_DEBUG 41/* 42 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal 43 * consistency checks. By default we don't do this unless 44 * CONFIG_JBD_DEBUG is on. 45 */ 46#define JBD_EXPENSIVE_CHECKING 47extern int journal_enable_debug; 48 49#define jbd_debug(n, f, a...) \ 50 do { \ 51 if ((n) <= journal_enable_debug) { \ 52 printk (KERN_DEBUG "(%s, %d): %s: ", \ 53 __FILE__, __LINE__, __FUNCTION__); \ 54 printk (f, ## a); \ 55 } \ 56 } while (0) 57#else 58#ifdef __GNUC__ 59#define jbd_debug(f, a...) /**/ 60#else 61#define jbd_debug(f, ...) /**/ 62#endif 63#endif 64#else 65#define jbd_debug(x) /* AIX doesn't do STDC */ 66#endif 67 68extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry); 69#define jbd_kmalloc(size, flags) \ 70 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry) 71#define jbd_rep_kmalloc(size, flags) \ 72 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1) 73 74#define JFS_MIN_JOURNAL_BLOCKS 1024 75 76#ifdef __KERNEL__ 77typedef struct handle_s handle_t; /* Atomic operation type */ 78typedef struct journal_s journal_t; /* Journal control structure */ 79#endif 80 81/* 82 * Internal structures used by the logging mechanism: 83 */ 84 85#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 86 87/* 88 * On-disk structures 89 */ 90 91/* 92 * Descriptor block types: 93 */ 94 95#define JFS_DESCRIPTOR_BLOCK 1 96#define JFS_COMMIT_BLOCK 2 97#define JFS_SUPERBLOCK_V1 3 98#define JFS_SUPERBLOCK_V2 4 99#define JFS_REVOKE_BLOCK 5 100 101/* 102 * Standard header for all descriptor blocks: 103 */ 104typedef struct journal_header_s 105{ 106 __u32 h_magic; 107 __u32 h_blocktype; 108 __u32 h_sequence; 109} journal_header_t; 110 111 112/* 113 * The block tag: used to describe a single buffer in the journal 114 */ 115typedef struct journal_block_tag_s 116{ 117 __u32 t_blocknr; /* The on-disk block number */ 118 __u32 t_flags; /* See below */ 119} journal_block_tag_t; 120 121/* 122 * The revoke descriptor: used on disk to describe a series of blocks to 123 * be revoked from the log 124 */ 125typedef struct journal_revoke_header_s 126{ 127 journal_header_t r_header; 128 int r_count; /* Count of bytes used in the block */ 129} journal_revoke_header_t; 130 131 132/* Definitions for the journal tag flags word: */ 133#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 134#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 135#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 136#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 137 138 139/* 140 * The journal superblock. All fields are in big-endian byte order. 141 */ 142typedef struct journal_superblock_s 143{ 144/* 0x0000 */ 145 journal_header_t s_header; 146 147/* 0x000C */ 148 /* Static information describing the journal */ 149 __u32 s_blocksize; /* journal device blocksize */ 150 __u32 s_maxlen; /* total blocks in journal file */ 151 __u32 s_first; /* first block of log information */ 152 153/* 0x0018 */ 154 /* Dynamic information describing the current state of the log */ 155 __u32 s_sequence; /* first commit ID expected in log */ 156 __u32 s_start; /* blocknr of start of log */ 157 158/* 0x0020 */ 159 /* Error value, as set by journal_abort(). */ 160 __s32 s_errno; 161 162/* 0x0024 */ 163 /* Remaining fields are only valid in a version-2 superblock */ 164 __u32 s_feature_compat; /* compatible feature set */ 165 __u32 s_feature_incompat; /* incompatible feature set */ 166 __u32 s_feature_ro_compat; /* readonly-compatible feature set */ 167/* 0x0030 */ 168 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 169 170/* 0x0040 */ 171 __u32 s_nr_users; /* Nr of filesystems sharing log */ 172 173 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 174 175/* 0x0048 */ 176 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/ 177 __u32 s_max_trans_data; /* Limit of data blocks per trans. */ 178 179/* 0x0050 */ 180 __u32 s_padding[44]; 181 182/* 0x0100 */ 183 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 184/* 0x0400 */ 185} journal_superblock_t; 186 187#define JFS_HAS_COMPAT_FEATURE(j,mask) \ 188 ((j)->j_format_version >= 2 && \ 189 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 190#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 191 ((j)->j_format_version >= 2 && \ 192 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 193#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 194 ((j)->j_format_version >= 2 && \ 195 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 196 197#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 198 199/* Features known to this kernel version: */ 200#define JFS_KNOWN_COMPAT_FEATURES 0 201#define JFS_KNOWN_ROCOMPAT_FEATURES 0 202#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE 203 204#ifdef __KERNEL__ 205 206#include <linux/fs.h> 207#include <linux/sched.h> 208 209#define JBD_ASSERTIONS 210#ifdef JBD_ASSERTIONS 211#define J_ASSERT(assert) \ 212do { \ 213 if (!(assert)) { \ 214 printk (KERN_EMERG \ 215 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 216 __FUNCTION__, __FILE__, __LINE__, # assert); \ 217 BUG(); \ 218 } \ 219} while (0) 220 221#if defined(CONFIG_BUFFER_DEBUG) 222void buffer_assertion_failure(struct buffer_head *bh); 223#define J_ASSERT_BH(bh, expr) \ 224 do { \ 225 if (!(expr)) \ 226 buffer_assertion_failure(bh); \ 227 J_ASSERT(expr); \ 228 } while (0) 229#define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 230#else 231#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 232#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 233#endif 234 235#else 236#define J_ASSERT(assert) 237#endif /* JBD_ASSERTIONS */ 238 239enum jbd_state_bits { 240 BH_JWrite 241 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */ 242 BH_Freed, /* 1 if buffer has been freed (truncated) */ 243 BH_Revoked, /* 1 if buffer has been revoked from the log */ 244 BH_RevokeValid, /* 1 if buffer revoked flag is valid */ 245 BH_JBDDirty, /* 1 if buffer is dirty but journaled */ 246}; 247 248/* Return true if the buffer is one which JBD is managing */ 249static inline int buffer_jbd(struct buffer_head *bh) 250{ 251 return __buffer_state(bh, JBD); 252} 253 254static inline struct buffer_head *jh2bh(struct journal_head *jh) 255{ 256 return jh->b_bh; 257} 258 259static inline struct journal_head *bh2jh(struct buffer_head *bh) 260{ 261 return bh->b_private; 262} 263 264struct jbd_revoke_table_s; 265 266/* The handle_t type represents a single atomic update being performed 267 * by some process. All filesystem modifications made by the process go 268 * through this handle. Recursive operations (such as quota operations) 269 * are gathered into a single update. 270 * 271 * The buffer credits field is used to account for journaled buffers 272 * being modified by the running process. To ensure that there is 273 * enough log space for all outstanding operations, we need to limit the 274 * number of outstanding buffers possible at any time. When the 275 * operation completes, any buffer credits not used are credited back to 276 * the transaction, so that at all times we know how many buffers the 277 * outstanding updates on a transaction might possibly touch. */ 278 279struct handle_s 280{ 281 /* Which compound transaction is this update a part of? */ 282 transaction_t * h_transaction; 283 284 /* Number of remaining buffers we are allowed to dirty: */ 285 int h_buffer_credits; 286 287 /* Reference count on this handle */ 288 int h_ref; 289 290 /* Field for caller's use to track errors through large fs 291 operations */ 292 int h_err; 293 294 /* Flags */ 295 unsigned int h_sync: 1; /* sync-on-close */ 296 unsigned int h_jdata: 1; /* force data journaling */ 297 unsigned int h_aborted: 1; /* fatal error on handle */ 298}; 299 300 301/* The transaction_t type is the guts of the journaling mechanism. It 302 * tracks a compound transaction through its various states: 303 * 304 * RUNNING: accepting new updates 305 * LOCKED: Updates still running but we don't accept new ones 306 * RUNDOWN: Updates are tidying up but have finished requesting 307 * new buffers to modify (state not used for now) 308 * FLUSH: All updates complete, but we are still writing to disk 309 * COMMIT: All data on disk, writing commit record 310 * FINISHED: We still have to keep the transaction for checkpointing. 311 * 312 * The transaction keeps track of all of the buffers modified by a 313 * running transaction, and all of the buffers committed but not yet 314 * flushed to home for finished transactions. 315 */ 316 317struct transaction_s 318{ 319 /* Pointer to the journal for this transaction. */ 320 journal_t * t_journal; 321 322 /* Sequence number for this transaction */ 323 tid_t t_tid; 324 325 /* Transaction's current state */ 326 enum { 327 T_RUNNING, 328 T_LOCKED, 329 T_RUNDOWN, 330 T_FLUSH, 331 T_COMMIT, 332 T_FINISHED 333 } t_state; 334 335 /* Where in the log does this transaction's commit start? */ 336 unsigned long t_log_start; 337 338 /* Doubly-linked circular list of all inodes owned by this 339 transaction */ /* AKPM: unused */ 340 struct inode * t_ilist; 341 342 /* Number of buffers on the t_buffers list */ 343 int t_nr_buffers; 344 345 /* Doubly-linked circular list of all buffers reserved but not 346 yet modified by this transaction */ 347 struct journal_head * t_reserved_list; 348 349 /* Doubly-linked circular list of all metadata buffers owned by this 350 transaction */ 351 struct journal_head * t_buffers; 352 353 /* 354 * Doubly-linked circular list of all data buffers still to be 355 * flushed before this transaction can be committed. 356 * Protected by journal_datalist_lock. 357 */ 358 struct journal_head * t_sync_datalist; 359 360 /* 361 * Doubly-linked circular list of all writepage data buffers 362 * still to be written before this transaction can be committed. 363 * Protected by journal_datalist_lock. 364 */ 365 struct journal_head * t_async_datalist; 366 367 /* Doubly-linked circular list of all forget buffers (superceded 368 buffers which we can un-checkpoint once this transaction 369 commits) */ 370 struct journal_head * t_forget; 371 372 /* 373 * Doubly-linked circular list of all buffers still to be 374 * flushed before this transaction can be checkpointed. 375 */ 376 /* Protected by journal_datalist_lock */ 377 struct journal_head * t_checkpoint_list; 378 379 /* Doubly-linked circular list of temporary buffers currently 380 undergoing IO in the log */ 381 struct journal_head * t_iobuf_list; 382 383 /* Doubly-linked circular list of metadata buffers being 384 shadowed by log IO. The IO buffers on the iobuf list and the 385 shadow buffers on this list match each other one for one at 386 all times. */ 387 struct journal_head * t_shadow_list; 388 389 /* Doubly-linked circular list of control buffers being written 390 to the log. */ 391 struct journal_head * t_log_list; 392 393 /* Number of outstanding updates running on this transaction */ 394 int t_updates; 395 396 /* Number of buffers reserved for use by all handles in this 397 * transaction handle but not yet modified. */ 398 int t_outstanding_credits; 399 400 /* 401 * Forward and backward links for the circular list of all 402 * transactions awaiting checkpoint. 403 */ 404 /* Protected by journal_datalist_lock */ 405 transaction_t *t_cpnext, *t_cpprev; 406 407 /* When will the transaction expire (become due for commit), in 408 * jiffies ? */ 409 unsigned long t_expires; 410 411 /* How many handles used this transaction? */ 412 int t_handle_count; 413}; 414 415 416/* The journal_t maintains all of the journaling state information for a 417 * single filesystem. It is linked to from the fs superblock structure. 418 * 419 * We use the journal_t to keep track of all outstanding transaction 420 * activity on the filesystem, and to manage the state of the log 421 * writing process. */ 422 423struct journal_s 424{ 425 /* General journaling state flags */ 426 unsigned long j_flags; 427 428 /* Is there an outstanding uncleared error on the journal (from 429 * a prior abort)? */ 430 int j_errno; 431 432 /* The superblock buffer */ 433 struct buffer_head * j_sb_buffer; 434 journal_superblock_t * j_superblock; 435 436 /* Version of the superblock format */ 437 int j_format_version; 438 439 /* Number of processes waiting to create a barrier lock */ 440 int j_barrier_count; 441 442 /* The barrier lock itself */ 443 struct semaphore j_barrier; 444 445 /* Transactions: The current running transaction... */ 446 transaction_t * j_running_transaction; 447 448 /* ... the transaction we are pushing to disk ... */ 449 transaction_t * j_committing_transaction; 450 451 /* ... and a linked circular list of all transactions waiting 452 * for checkpointing. */ 453 /* Protected by journal_datalist_lock */ 454 transaction_t * j_checkpoint_transactions; 455 456 /* Wait queue for waiting for a locked transaction to start 457 committing, or for a barrier lock to be released */ 458 wait_queue_head_t j_wait_transaction_locked; 459 460 /* Wait queue for waiting for checkpointing to complete */ 461 wait_queue_head_t j_wait_logspace; 462 463 /* Wait queue for waiting for commit to complete */ 464 wait_queue_head_t j_wait_done_commit; 465 466 /* Wait queue to trigger checkpointing */ 467 wait_queue_head_t j_wait_checkpoint; 468 469 /* Wait queue to trigger commit */ 470 wait_queue_head_t j_wait_commit; 471 472 /* Wait queue to wait for updates to complete */ 473 wait_queue_head_t j_wait_updates; 474 475 /* Semaphore for locking against concurrent checkpoints */ 476 struct semaphore j_checkpoint_sem; 477 478 /* The main journal lock, used by lock_journal() */ 479 struct semaphore j_sem; 480 481 /* Journal head: identifies the first unused block in the journal. */ 482 unsigned long j_head; 483 484 /* Journal tail: identifies the oldest still-used block in the 485 * journal. */ 486 unsigned long j_tail; 487 488 /* Journal free: how many free blocks are there in the journal? */ 489 unsigned long j_free; 490 491 /* Journal start and end: the block numbers of the first usable 492 * block and one beyond the last usable block in the journal. */ 493 unsigned long j_first, j_last; 494 495 /* Device, blocksize and starting block offset for the location 496 * where we store the journal. */ 497 kdev_t j_dev; 498 int j_blocksize; 499 unsigned int j_blk_offset; 500 501 /* Device which holds the client fs. For internal journal this 502 * will be equal to j_dev. */ 503 kdev_t j_fs_dev; 504 505 /* Total maximum capacity of the journal region on disk. */ 506 unsigned int j_maxlen; 507 508 /* Optional inode where we store the journal. If present, all 509 * journal block numbers are mapped into this inode via 510 * bmap(). */ 511 struct inode * j_inode; 512 513 /* Sequence number of the oldest transaction in the log */ 514 tid_t j_tail_sequence; 515 /* Sequence number of the next transaction to grant */ 516 tid_t j_transaction_sequence; 517 /* Sequence number of the most recently committed transaction */ 518 tid_t j_commit_sequence; 519 /* Sequence number of the most recent transaction wanting commit */ 520 tid_t j_commit_request; 521 522 /* Journal uuid: identifies the object (filesystem, LVM volume 523 * etc) backed by this journal. This will eventually be 524 * replaced by an array of uuids, allowing us to index multiple 525 * devices within a single journal and to perform atomic updates 526 * across them. */ 527 528 __u8 j_uuid[16]; 529 530 /* Pointer to the current commit thread for this journal */ 531 struct task_struct * j_task; 532 533 /* Maximum number of metadata buffers to allow in a single 534 * compound commit transaction */ 535 int j_max_transaction_buffers; 536 537 /* What is the maximum transaction lifetime before we begin a 538 * commit? */ 539 unsigned long j_commit_interval; 540 541 /* The timer used to wakeup the commit thread: */ 542 struct timer_list * j_commit_timer; 543 int j_commit_timer_active; 544 545 /* Link all journals together - system-wide */ 546 struct list_head j_all_journals; 547 548 /* The revoke table: maintains the list of revoked blocks in the 549 current transaction. */ 550 struct jbd_revoke_table_s *j_revoke; 551}; 552 553/* 554 * Journal flag definitions 555 */ 556#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 557#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 558#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 559#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 560#define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 561 562/* 563 * Function declarations for the journaling transaction and buffer 564 * management 565 */ 566 567/* Filing buffers */ 568extern void __journal_unfile_buffer(struct journal_head *); 569extern void journal_unfile_buffer(struct journal_head *); 570extern void __journal_refile_buffer(struct journal_head *); 571extern void journal_refile_buffer(struct journal_head *); 572extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 573extern void __journal_free_buffer(struct journal_head *bh); 574extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 575extern void __journal_clean_data_list(transaction_t *transaction); 576 577/* Log buffer allocation */ 578extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 579extern unsigned long journal_next_log_block(journal_t *); 580 581/* Commit management */ 582extern void journal_commit_transaction(journal_t *); 583 584/* Checkpoint list management */ 585int __journal_clean_checkpoint_list(journal_t *journal); 586extern void journal_remove_checkpoint(struct journal_head *); 587extern void __journal_remove_checkpoint(struct journal_head *); 588extern void journal_insert_checkpoint(struct journal_head *, transaction_t *); 589extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *); 590 591/* Buffer IO */ 592extern int 593journal_write_metadata_buffer(transaction_t *transaction, 594 struct journal_head *jh_in, 595 struct journal_head **jh_out, 596 int blocknr); 597 598/* Transaction locking */ 599extern void __wait_on_journal (journal_t *); 600 601/* 602 * Journal locking. 603 * 604 * We need to lock the journal during transaction state changes so that 605 * nobody ever tries to take a handle on the running transaction while 606 * we are in the middle of moving it to the commit phase. 607 * 608 * Note that the locking is completely interrupt unsafe. We never touch 609 * journal structures from interrupts. 610 * 611 * In 2.2, the BKL was required for lock_journal. This is no longer 612 * the case. 613 */ 614 615static inline void lock_journal(journal_t *journal) 616{ 617 down(&journal->j_sem); 618} 619 620/* This returns zero if we acquired the semaphore */ 621static inline int try_lock_journal(journal_t * journal) 622{ 623 return down_trylock(&journal->j_sem); 624} 625 626static inline void unlock_journal(journal_t * journal) 627{ 628 up(&journal->j_sem); 629} 630 631 632static inline handle_t *journal_current_handle(void) 633{ 634 return current->journal_info; 635} 636 637/* The journaling code user interface: 638 * 639 * Create and destroy handles 640 * Register buffer modifications against the current transaction. 641 */ 642 643extern handle_t *journal_start(journal_t *, int nblocks); 644extern handle_t *journal_try_start(journal_t *, int nblocks); 645extern int journal_restart (handle_t *, int nblocks); 646extern int journal_extend (handle_t *, int nblocks); 647extern int journal_get_write_access (handle_t *, struct buffer_head *); 648extern int journal_get_create_access (handle_t *, struct buffer_head *); 649extern int journal_get_undo_access (handle_t *, struct buffer_head *); 650extern int journal_dirty_data (handle_t *, 651 struct buffer_head *, int async); 652extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 653extern void journal_release_buffer (handle_t *, struct buffer_head *); 654extern void journal_forget (handle_t *, struct buffer_head *); 655extern void journal_sync_buffer (struct buffer_head *); 656extern int journal_flushpage(journal_t *, struct page *, unsigned long); 657extern int journal_try_to_free_buffers(journal_t *, struct page *, int); 658extern int journal_stop(handle_t *); 659extern int journal_flush (journal_t *); 660 661extern void journal_lock_updates (journal_t *); 662extern void journal_unlock_updates (journal_t *); 663 664extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev, 665 int start, int len, int bsize); 666extern journal_t * journal_init_inode (struct inode *); 667extern int journal_update_format (journal_t *); 668extern int journal_check_used_features 669 (journal_t *, unsigned long, unsigned long, unsigned long); 670extern int journal_check_available_features 671 (journal_t *, unsigned long, unsigned long, unsigned long); 672extern int journal_set_features 673 (journal_t *, unsigned long, unsigned long, unsigned long); 674extern int journal_create (journal_t *); 675extern int journal_load (journal_t *journal); 676extern void journal_destroy (journal_t *); 677extern int journal_recover (journal_t *journal); 678extern int journal_wipe (journal_t *, int); 679extern int journal_skip_recovery (journal_t *); 680extern void journal_update_superblock (journal_t *, int); 681extern void __journal_abort (journal_t *); 682extern void journal_abort (journal_t *, int); 683extern int journal_errno (journal_t *); 684extern void journal_ack_err (journal_t *); 685extern int journal_clear_err (journal_t *); 686extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr); 687extern int journal_force_commit(journal_t *journal); 688 689/* 690 * journal_head management 691 */ 692extern struct journal_head 693 *journal_add_journal_head(struct buffer_head *bh); 694extern void journal_remove_journal_head(struct buffer_head *bh); 695extern void __journal_remove_journal_head(struct buffer_head *bh); 696extern void journal_unlock_journal_head(struct journal_head *jh); 697 698/* Primary revoke support */ 699#define JOURNAL_REVOKE_DEFAULT_HASH 256 700extern int journal_init_revoke(journal_t *, int); 701extern void journal_destroy_revoke_caches(void); 702extern int journal_init_revoke_caches(void); 703 704extern void journal_destroy_revoke(journal_t *); 705extern int journal_revoke (handle_t *, 706 unsigned long, struct buffer_head *); 707extern int journal_cancel_revoke(handle_t *, struct journal_head *); 708extern void journal_write_revoke_records(journal_t *, transaction_t *); 709 710/* Recovery revoke support */ 711extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 712extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 713extern void journal_clear_revoke(journal_t *); 714extern void journal_brelse_array(struct buffer_head *b[], int n); 715 716/* The log thread user interface: 717 * 718 * Request space in the current transaction, and force transaction commit 719 * transitions on demand. 720 */ 721 722extern int log_space_left (journal_t *); /* Called with journal locked */ 723extern tid_t log_start_commit (journal_t *, transaction_t *); 724extern void log_wait_commit (journal_t *, tid_t); 725extern int log_do_checkpoint (journal_t *, int); 726 727extern void log_wait_for_space(journal_t *, int nblocks); 728extern void __journal_drop_transaction(journal_t *, transaction_t *); 729extern int cleanup_journal_tail(journal_t *); 730 731/* Reduce journal memory usage by flushing */ 732extern void shrink_journal_memory(void); 733 734/* Debugging code only: */ 735 736#define jbd_ENOSYS() \ 737do { \ 738 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \ 739 current->state = TASK_UNINTERRUPTIBLE; \ 740 schedule(); \ 741} while (1) 742 743/* 744 * is_journal_abort 745 * 746 * Simple test wrapper function to test the JFS_ABORT state flag. This 747 * bit, when set, indicates that we have had a fatal error somewhere, 748 * either inside the journaling layer or indicated to us by the client 749 * (eg. ext3), and that we and should not commit any further 750 * transactions. 751 */ 752 753static inline int is_journal_aborted(journal_t *journal) 754{ 755 return journal->j_flags & JFS_ABORT; 756} 757 758static inline int is_handle_aborted(handle_t *handle) 759{ 760 if (handle->h_aborted) 761 return 1; 762 return is_journal_aborted(handle->h_transaction->t_journal); 763} 764 765static inline void journal_abort_handle(handle_t *handle) 766{ 767 handle->h_aborted = 1; 768} 769 770/* Not all architectures define BUG() */ 771#ifndef BUG 772#define BUG() do { \ 773 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \ 774 * ((char *) 0) = 0; \ 775 } while (0) 776#endif /* BUG */ 777 778#else 779 780extern int journal_recover (journal_t *journal); 781extern int journal_skip_recovery (journal_t *); 782 783/* Primary revoke support */ 784extern int journal_init_revoke(journal_t *, int); 785extern void journal_destroy_revoke_caches(void); 786extern int journal_init_revoke_caches(void); 787 788/* Recovery revoke support */ 789extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 790extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 791extern void journal_clear_revoke(journal_t *); 792extern void journal_brelse_array(struct buffer_head *b[], int n); 793 794extern void journal_destroy_revoke(journal_t *); 795#endif /* __KERNEL__ */ 796 797static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 798static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 799 800/* Comparison functions for transaction IDs: perform comparisons using 801 * modulo arithmetic so that they work over sequence number wraps. */ 802 803static inline int tid_gt(tid_t x, tid_t y) 804{ 805 int difference = (x - y); 806 return (difference > 0); 807} 808 809static inline int tid_geq(tid_t x, tid_t y) 810{ 811 int difference = (x - y); 812 return (difference >= 0); 813} 814 815extern int journal_blocks_per_page(struct inode *inode); 816 817/* 818 * Definitions which augment the buffer_head layer 819 */ 820 821/* journaling buffer types */ 822#define BJ_None 0 /* Not journaled */ 823#define BJ_SyncData 1 /* Normal data: flush before commit */ 824#define BJ_AsyncData 2 /* writepage data: wait on it before commit */ 825#define BJ_Metadata 3 /* Normal journaled metadata */ 826#define BJ_Forget 4 /* Buffer superceded by this transaction */ 827#define BJ_IO 5 /* Buffer is for temporary IO use */ 828#define BJ_Shadow 6 /* Buffer contents being shadowed to the log */ 829#define BJ_LogCtl 7 /* Buffer contains log descriptors */ 830#define BJ_Reserved 8 /* Buffer is reserved for access by journal */ 831#define BJ_Types 9 832 833extern int jbd_blocks_per_page(struct inode *inode); 834 835#ifdef __KERNEL__ 836 837extern spinlock_t jh_splice_lock; 838/* 839 * Once `expr1' has been found true, take jh_splice_lock 840 * and then reevaluate everything. 841 */ 842#define SPLICE_LOCK(expr1, expr2) \ 843 ({ \ 844 int ret = (expr1); \ 845 if (ret) { \ 846 spin_lock(&jh_splice_lock); \ 847 ret = (expr1) && (expr2); \ 848 spin_unlock(&jh_splice_lock); \ 849 } \ 850 ret; \ 851 }) 852 853/* 854 * A number of buffer state predicates. They test for 855 * buffer_jbd() because they are used in core kernel code. 856 * 857 * These will be racy on SMP unless we're *sure* that the 858 * buffer won't be detached from the journalling system 859 * in parallel. 860 */ 861 862/* Return true if the buffer is on journal list `list' */ 863static inline int buffer_jlist_eq(struct buffer_head *bh, int list) 864{ 865 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list); 866} 867 868/* Return true if this bufer is dirty wrt the journal */ 869static inline int buffer_jdirty(struct buffer_head *bh) 870{ 871 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty); 872} 873 874/* Return true if it's a data buffer which journalling is managing */ 875static inline int buffer_jbd_data(struct buffer_head *bh) 876{ 877 return SPLICE_LOCK(buffer_jbd(bh), 878 bh2jh(bh)->b_jlist == BJ_SyncData || 879 bh2jh(bh)->b_jlist == BJ_AsyncData); 880} 881 882#ifdef CONFIG_SMP 883#define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock)) 884#else 885#define assert_spin_locked(lock) do {} while(0) 886#endif 887 888#define buffer_trace_init(bh) do {} while (0) 889#define print_buffer_fields(bh) do {} while (0) 890#define print_buffer_trace(bh) do {} while (0) 891#define BUFFER_TRACE(bh, info) do {} while (0) 892#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 893#define JBUFFER_TRACE(jh, info) do {} while (0) 894 895#endif /* __KERNEL__ */ 896 897#endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */ 898 899/* 900 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD 901 * go here. 902 */ 903 904#if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE)) 905 906#define J_ASSERT(expr) do {} while (0) 907#define J_ASSERT_BH(bh, expr) do {} while (0) 908#define buffer_jbd(bh) 0 909#define buffer_jlist_eq(bh, val) 0 910#define journal_buffer_journal_lru(bh) 0 911 912#endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */ 913#endif /* _LINUX_JBD_H */ 914