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 * Checksum types. 113 */ 114#define JBD2_CRC32_CHKSUM 1 115#define JBD2_MD5_CHKSUM 2 116#define JBD2_SHA1_CHKSUM 3 117 118#define JBD2_CRC32_CHKSUM_SIZE 4 119 120#define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32)) 121/* 122 * Commit block header for storing transactional checksums: 123 */ 124struct commit_header { 125 __u32 h_magic; 126 __u32 h_blocktype; 127 __u32 h_sequence; 128 unsigned char h_chksum_type; 129 unsigned char h_chksum_size; 130 unsigned char h_padding[2]; 131 __u32 h_chksum[JBD2_CHECKSUM_BYTES]; 132 __u64 h_commit_sec; 133 __u32 h_commit_nsec; 134}; 135 136/* 137 * The block tag: used to describe a single buffer in the journal 138 */ 139typedef struct journal_block_tag_s 140{ 141 __u32 t_blocknr; /* The on-disk block number */ 142 __u32 t_flags; /* See below */ 143 __u32 t_blocknr_high; /* most-significant high 32bits. */ 144} journal_block_tag_t; 145 146#define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t)) 147#define JBD_TAG_SIZE32 (8) 148 149/* 150 * The revoke descriptor: used on disk to describe a series of blocks to 151 * be revoked from the log 152 */ 153typedef struct journal_revoke_header_s 154{ 155 journal_header_t r_header; 156 int r_count; /* Count of bytes used in the block */ 157} journal_revoke_header_t; 158 159 160/* Definitions for the journal tag flags word: */ 161#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 162#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 163#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 164#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 165 166 167/* 168 * The journal superblock. All fields are in big-endian byte order. 169 */ 170typedef struct journal_superblock_s 171{ 172/* 0x0000 */ 173 journal_header_t s_header; 174 175/* 0x000C */ 176 /* Static information describing the journal */ 177 __u32 s_blocksize; /* journal device blocksize */ 178 __u32 s_maxlen; /* total blocks in journal file */ 179 __u32 s_first; /* first block of log information */ 180 181/* 0x0018 */ 182 /* Dynamic information describing the current state of the log */ 183 __u32 s_sequence; /* first commit ID expected in log */ 184 __u32 s_start; /* blocknr of start of log */ 185 186/* 0x0020 */ 187 /* Error value, as set by journal_abort(). */ 188 __s32 s_errno; 189 190/* 0x0024 */ 191 /* Remaining fields are only valid in a version-2 superblock */ 192 __u32 s_feature_compat; /* compatible feature set */ 193 __u32 s_feature_incompat; /* incompatible feature set */ 194 __u32 s_feature_ro_compat; /* readonly-compatible feature set */ 195/* 0x0030 */ 196 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 197 198/* 0x0040 */ 199 __u32 s_nr_users; /* Nr of filesystems sharing log */ 200 201 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 202 203/* 0x0048 */ 204 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/ 205 __u32 s_max_trans_data; /* Limit of data blocks per trans. */ 206 207/* 0x0050 */ 208 __u32 s_padding[44]; 209 210/* 0x0100 */ 211 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 212/* 0x0400 */ 213} journal_superblock_t; 214 215#define JFS_HAS_COMPAT_FEATURE(j,mask) \ 216 ((j)->j_format_version >= 2 && \ 217 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 218#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 219 ((j)->j_format_version >= 2 && \ 220 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 221#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 222 ((j)->j_format_version >= 2 && \ 223 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 224 225#define JFS_FEATURE_COMPAT_CHECKSUM 0x00000001 226 227#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 228 229#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 230#define JFS_FEATURE_INCOMPAT_64BIT 0x00000002 231#define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 232 233/* Features known to this kernel version: */ 234#define JFS_KNOWN_COMPAT_FEATURES 0 235#define JFS_KNOWN_ROCOMPAT_FEATURES 0 236#define JFS_KNOWN_INCOMPAT_FEATURES (JFS_FEATURE_INCOMPAT_REVOKE|\ 237 JFS_FEATURE_INCOMPAT_ASYNC_COMMIT) 238 239#ifdef __KERNEL__ 240 241#include <linux/fs.h> 242#include <linux/sched.h> 243 244#define JBD_ASSERTIONS 245#ifdef JBD_ASSERTIONS 246#define J_ASSERT(assert) \ 247do { \ 248 if (!(assert)) { \ 249 printk (KERN_EMERG \ 250 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 251 __FUNCTION__, __FILE__, __LINE__, # assert); \ 252 BUG(); \ 253 } \ 254} while (0) 255 256#if defined(CONFIG_BUFFER_DEBUG) 257void buffer_assertion_failure(struct buffer_head *bh); 258#define J_ASSERT_BH(bh, expr) \ 259 do { \ 260 if (!(expr)) \ 261 buffer_assertion_failure(bh); \ 262 J_ASSERT(expr); \ 263 } while (0) 264#define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 265#else 266#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 267#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 268#endif 269 270#else 271#define J_ASSERT(assert) 272#endif /* JBD_ASSERTIONS */ 273 274enum jbd_state_bits { 275 BH_JWrite 276 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */ 277 BH_Freed, /* 1 if buffer has been freed (truncated) */ 278 BH_Revoked, /* 1 if buffer has been revoked from the log */ 279 BH_RevokeValid, /* 1 if buffer revoked flag is valid */ 280 BH_JBDDirty, /* 1 if buffer is dirty but journaled */ 281}; 282 283/* Return true if the buffer is one which JBD is managing */ 284static inline int buffer_jbd(struct buffer_head *bh) 285{ 286 return __buffer_state(bh, JBD); 287} 288 289static inline struct buffer_head *jh2bh(struct journal_head *jh) 290{ 291 return jh->b_bh; 292} 293 294static inline struct journal_head *bh2jh(struct buffer_head *bh) 295{ 296 return bh->b_private; 297} 298 299struct jbd_revoke_table_s; 300 301/* The handle_t type represents a single atomic update being performed 302 * by some process. All filesystem modifications made by the process go 303 * through this handle. Recursive operations (such as quota operations) 304 * are gathered into a single update. 305 * 306 * The buffer credits field is used to account for journaled buffers 307 * being modified by the running process. To ensure that there is 308 * enough log space for all outstanding operations, we need to limit the 309 * number of outstanding buffers possible at any time. When the 310 * operation completes, any buffer credits not used are credited back to 311 * the transaction, so that at all times we know how many buffers the 312 * outstanding updates on a transaction might possibly touch. */ 313 314struct handle_s 315{ 316 /* Which compound transaction is this update a part of? */ 317 transaction_t * h_transaction; 318 319 /* Number of remaining buffers we are allowed to dirty: */ 320 int h_buffer_credits; 321 322 /* Reference count on this handle */ 323 int h_ref; 324 325 /* Field for caller's use to track errors through large fs 326 operations */ 327 int h_err; 328 329 /* Flags */ 330 unsigned int h_sync: 1; /* sync-on-close */ 331 unsigned int h_jdata: 1; /* force data journaling */ 332 unsigned int h_aborted: 1; /* fatal error on handle */ 333}; 334 335 336/* The transaction_t type is the guts of the journaling mechanism. It 337 * tracks a compound transaction through its various states: 338 * 339 * RUNNING: accepting new updates 340 * LOCKED: Updates still running but we don't accept new ones 341 * RUNDOWN: Updates are tidying up but have finished requesting 342 * new buffers to modify (state not used for now) 343 * FLUSH: All updates complete, but we are still writing to disk 344 * COMMIT: All data on disk, writing commit record 345 * FINISHED: We still have to keep the transaction for checkpointing. 346 * 347 * The transaction keeps track of all of the buffers modified by a 348 * running transaction, and all of the buffers committed but not yet 349 * flushed to home for finished transactions. 350 */ 351 352struct transaction_s 353{ 354 /* Pointer to the journal for this transaction. */ 355 journal_t * t_journal; 356 357 /* Sequence number for this transaction */ 358 tid_t t_tid; 359 360 /* Transaction's current state */ 361 enum { 362 T_RUNNING, 363 T_LOCKED, 364 T_RUNDOWN, 365 T_FLUSH, 366 T_COMMIT, 367 T_FINISHED 368 } t_state; 369 370 /* Where in the log does this transaction's commit start? */ 371 unsigned long t_log_start; 372 373 /* Doubly-linked circular list of all inodes owned by this 374 transaction */ /* AKPM: unused */ 375 struct inode * t_ilist; 376 377 /* Number of buffers on the t_buffers list */ 378 int t_nr_buffers; 379 380 /* Doubly-linked circular list of all buffers reserved but not 381 yet modified by this transaction */ 382 struct journal_head * t_reserved_list; 383 384 /* Doubly-linked circular list of all metadata buffers owned by this 385 transaction */ 386 struct journal_head * t_buffers; 387 388 /* 389 * Doubly-linked circular list of all data buffers still to be 390 * flushed before this transaction can be committed. 391 * Protected by journal_datalist_lock. 392 */ 393 struct journal_head * t_sync_datalist; 394 395 /* 396 * Doubly-linked circular list of all writepage data buffers 397 * still to be written before this transaction can be committed. 398 * Protected by journal_datalist_lock. 399 */ 400 struct journal_head * t_async_datalist; 401 402 /* Doubly-linked circular list of all forget buffers (superceded 403 buffers which we can un-checkpoint once this transaction 404 commits) */ 405 struct journal_head * t_forget; 406 407 /* 408 * Doubly-linked circular list of all buffers still to be 409 * flushed before this transaction can be checkpointed. 410 */ 411 /* Protected by journal_datalist_lock */ 412 struct journal_head * t_checkpoint_list; 413 414 /* Doubly-linked circular list of temporary buffers currently 415 undergoing IO in the log */ 416 struct journal_head * t_iobuf_list; 417 418 /* Doubly-linked circular list of metadata buffers being 419 shadowed by log IO. The IO buffers on the iobuf list and the 420 shadow buffers on this list match each other one for one at 421 all times. */ 422 struct journal_head * t_shadow_list; 423 424 /* Doubly-linked circular list of control buffers being written 425 to the log. */ 426 struct journal_head * t_log_list; 427 428 /* Number of outstanding updates running on this transaction */ 429 int t_updates; 430 431 /* Number of buffers reserved for use by all handles in this 432 * transaction handle but not yet modified. */ 433 int t_outstanding_credits; 434 435 /* 436 * Forward and backward links for the circular list of all 437 * transactions awaiting checkpoint. 438 */ 439 /* Protected by journal_datalist_lock */ 440 transaction_t *t_cpnext, *t_cpprev; 441 442 /* When will the transaction expire (become due for commit), in 443 * jiffies ? */ 444 unsigned long t_expires; 445 446 /* How many handles used this transaction? */ 447 int t_handle_count; 448}; 449 450 451/* The journal_t maintains all of the journaling state information for a 452 * single filesystem. It is linked to from the fs superblock structure. 453 * 454 * We use the journal_t to keep track of all outstanding transaction 455 * activity on the filesystem, and to manage the state of the log 456 * writing process. */ 457 458struct journal_s 459{ 460 /* General journaling state flags */ 461 unsigned long j_flags; 462 463 /* Is there an outstanding uncleared error on the journal (from 464 * a prior abort)? */ 465 int j_errno; 466 467 /* The superblock buffer */ 468 struct buffer_head * j_sb_buffer; 469 journal_superblock_t * j_superblock; 470 471 /* Version of the superblock format */ 472 int j_format_version; 473 474 /* Number of processes waiting to create a barrier lock */ 475 int j_barrier_count; 476 477 /* The barrier lock itself */ 478 struct semaphore j_barrier; 479 480 /* Transactions: The current running transaction... */ 481 transaction_t * j_running_transaction; 482 483 /* ... the transaction we are pushing to disk ... */ 484 transaction_t * j_committing_transaction; 485 486 /* ... and a linked circular list of all transactions waiting 487 * for checkpointing. */ 488 /* Protected by journal_datalist_lock */ 489 transaction_t * j_checkpoint_transactions; 490 491 /* Wait queue for waiting for a locked transaction to start 492 committing, or for a barrier lock to be released */ 493 wait_queue_head_t j_wait_transaction_locked; 494 495 /* Wait queue for waiting for checkpointing to complete */ 496 wait_queue_head_t j_wait_logspace; 497 498 /* Wait queue for waiting for commit to complete */ 499 wait_queue_head_t j_wait_done_commit; 500 501 /* Wait queue to trigger checkpointing */ 502 wait_queue_head_t j_wait_checkpoint; 503 504 /* Wait queue to trigger commit */ 505 wait_queue_head_t j_wait_commit; 506 507 /* Wait queue to wait for updates to complete */ 508 wait_queue_head_t j_wait_updates; 509 510 /* Semaphore for locking against concurrent checkpoints */ 511 struct semaphore j_checkpoint_sem; 512 513 /* The main journal lock, used by lock_journal() */ 514 struct semaphore j_sem; 515 516 /* Journal head: identifies the first unused block in the journal. */ 517 unsigned long j_head; 518 519 /* Journal tail: identifies the oldest still-used block in the 520 * journal. */ 521 unsigned long j_tail; 522 523 /* Journal free: how many free blocks are there in the journal? */ 524 unsigned long j_free; 525 526 /* Journal start and end: the block numbers of the first usable 527 * block and one beyond the last usable block in the journal. */ 528 unsigned long j_first, j_last; 529 530 /* Device, blocksize and starting block offset for the location 531 * where we store the journal. */ 532 kdev_t j_dev; 533 int j_blocksize; 534 unsigned int j_blk_offset; 535 536 /* Device which holds the client fs. For internal journal this 537 * will be equal to j_dev. */ 538 kdev_t j_fs_dev; 539 540 /* Total maximum capacity of the journal region on disk. */ 541 unsigned int j_maxlen; 542 543 /* Optional inode where we store the journal. If present, all 544 * journal block numbers are mapped into this inode via 545 * bmap(). */ 546 struct inode * j_inode; 547 548 /* Sequence number of the oldest transaction in the log */ 549 tid_t j_tail_sequence; 550 /* Sequence number of the next transaction to grant */ 551 tid_t j_transaction_sequence; 552 /* Sequence number of the most recently committed transaction */ 553 tid_t j_commit_sequence; 554 /* Sequence number of the most recent transaction wanting commit */ 555 tid_t j_commit_request; 556 557 /* Journal uuid: identifies the object (filesystem, LVM volume 558 * etc) backed by this journal. This will eventually be 559 * replaced by an array of uuids, allowing us to index multiple 560 * devices within a single journal and to perform atomic updates 561 * across them. */ 562 563 __u8 j_uuid[16]; 564 565 /* Pointer to the current commit thread for this journal */ 566 struct task_struct * j_task; 567 568 /* Maximum number of metadata buffers to allow in a single 569 * compound commit transaction */ 570 int j_max_transaction_buffers; 571 572 /* What is the maximum transaction lifetime before we begin a 573 * commit? */ 574 unsigned long j_commit_interval; 575 576 /* The timer used to wakeup the commit thread: */ 577 struct timer_list * j_commit_timer; 578 int j_commit_timer_active; 579 580 /* Link all journals together - system-wide */ 581 struct list_head j_all_journals; 582 583 /* The revoke table: maintains the list of revoked blocks in the 584 current transaction. */ 585 struct jbd_revoke_table_s *j_revoke; 586 587 /* Failed journal commit ID */ 588 unsigned int j_failed_commit; 589}; 590 591/* 592 * Journal flag definitions 593 */ 594#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 595#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 596#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 597#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 598#define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 599 600/* 601 * Function declarations for the journaling transaction and buffer 602 * management 603 */ 604 605/* Filing buffers */ 606extern void __journal_unfile_buffer(struct journal_head *); 607extern void journal_unfile_buffer(struct journal_head *); 608extern void __journal_refile_buffer(struct journal_head *); 609extern void journal_refile_buffer(struct journal_head *); 610extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 611extern void __journal_free_buffer(struct journal_head *bh); 612extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 613extern void __journal_clean_data_list(transaction_t *transaction); 614 615/* Log buffer allocation */ 616extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 617extern unsigned long journal_next_log_block(journal_t *); 618 619/* Commit management */ 620extern void journal_commit_transaction(journal_t *); 621 622/* Checkpoint list management */ 623int __journal_clean_checkpoint_list(journal_t *journal); 624extern void journal_remove_checkpoint(struct journal_head *); 625extern void __journal_remove_checkpoint(struct journal_head *); 626extern void journal_insert_checkpoint(struct journal_head *, transaction_t *); 627extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *); 628 629/* Buffer IO */ 630extern int 631journal_write_metadata_buffer(transaction_t *transaction, 632 struct journal_head *jh_in, 633 struct journal_head **jh_out, 634 int blocknr); 635 636/* Transaction locking */ 637extern void __wait_on_journal (journal_t *); 638 639/* 640 * Journal locking. 641 * 642 * We need to lock the journal during transaction state changes so that 643 * nobody ever tries to take a handle on the running transaction while 644 * we are in the middle of moving it to the commit phase. 645 * 646 * Note that the locking is completely interrupt unsafe. We never touch 647 * journal structures from interrupts. 648 * 649 * In 2.2, the BKL was required for lock_journal. This is no longer 650 * the case. 651 */ 652 653static inline void lock_journal(journal_t *journal) 654{ 655 down(&journal->j_sem); 656} 657 658/* This returns zero if we acquired the semaphore */ 659static inline int try_lock_journal(journal_t * journal) 660{ 661 return down_trylock(&journal->j_sem); 662} 663 664static inline void unlock_journal(journal_t * journal) 665{ 666 up(&journal->j_sem); 667} 668 669 670static inline handle_t *journal_current_handle(void) 671{ 672 return current->journal_info; 673} 674 675/* The journaling code user interface: 676 * 677 * Create and destroy handles 678 * Register buffer modifications against the current transaction. 679 */ 680 681extern handle_t *journal_start(journal_t *, int nblocks); 682extern handle_t *journal_try_start(journal_t *, int nblocks); 683extern int journal_restart (handle_t *, int nblocks); 684extern int journal_extend (handle_t *, int nblocks); 685extern int journal_get_write_access (handle_t *, struct buffer_head *); 686extern int journal_get_create_access (handle_t *, struct buffer_head *); 687extern int journal_get_undo_access (handle_t *, struct buffer_head *); 688extern int journal_dirty_data (handle_t *, 689 struct buffer_head *, int async); 690extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 691extern void journal_release_buffer (handle_t *, struct buffer_head *); 692extern void journal_forget (handle_t *, struct buffer_head *); 693extern void journal_sync_buffer (struct buffer_head *); 694extern int journal_flushpage(journal_t *, struct page *, unsigned long); 695extern int journal_try_to_free_buffers(journal_t *, struct page *, int); 696extern int journal_stop(handle_t *); 697extern int journal_flush (journal_t *); 698 699extern void journal_lock_updates (journal_t *); 700extern void journal_unlock_updates (journal_t *); 701 702extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev, 703 int start, int len, int bsize); 704extern journal_t * journal_init_inode (struct inode *); 705extern int journal_update_format (journal_t *); 706extern int journal_check_used_features 707 (journal_t *, unsigned long, unsigned long, unsigned long); 708extern int journal_check_available_features 709 (journal_t *, unsigned long, unsigned long, unsigned long); 710extern int journal_set_features 711 (journal_t *, unsigned long, unsigned long, unsigned long); 712extern int journal_create (journal_t *); 713extern int journal_load (journal_t *journal); 714extern void journal_destroy (journal_t *); 715extern int journal_recover (journal_t *journal); 716extern int journal_wipe (journal_t *, int); 717extern int journal_skip_recovery (journal_t *); 718extern void journal_update_superblock (journal_t *, int); 719extern void __journal_abort (journal_t *); 720extern void journal_abort (journal_t *, int); 721extern int journal_errno (journal_t *); 722extern void journal_ack_err (journal_t *); 723extern int journal_clear_err (journal_t *); 724extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr); 725extern int journal_force_commit(journal_t *journal); 726 727/* 728 * journal_head management 729 */ 730extern struct journal_head 731 *journal_add_journal_head(struct buffer_head *bh); 732extern void journal_remove_journal_head(struct buffer_head *bh); 733extern void __journal_remove_journal_head(struct buffer_head *bh); 734extern void journal_unlock_journal_head(struct journal_head *jh); 735 736/* Primary revoke support */ 737#define JOURNAL_REVOKE_DEFAULT_HASH 256 738extern int journal_init_revoke(journal_t *, int); 739extern void journal_destroy_revoke_caches(void); 740extern int journal_init_revoke_caches(void); 741 742extern void journal_destroy_revoke(journal_t *); 743extern int journal_revoke (handle_t *, 744 unsigned long, struct buffer_head *); 745extern int journal_cancel_revoke(handle_t *, struct journal_head *); 746extern void journal_write_revoke_records(journal_t *, transaction_t *); 747 748/* Recovery revoke support */ 749extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 750extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 751extern void journal_clear_revoke(journal_t *); 752extern void journal_brelse_array(struct buffer_head *b[], int n); 753 754/* The log thread user interface: 755 * 756 * Request space in the current transaction, and force transaction commit 757 * transitions on demand. 758 */ 759 760extern int log_space_left (journal_t *); /* Called with journal locked */ 761extern tid_t log_start_commit (journal_t *, transaction_t *); 762extern void log_wait_commit (journal_t *, tid_t); 763extern int log_do_checkpoint (journal_t *, int); 764 765extern void log_wait_for_space(journal_t *, int nblocks); 766extern void __journal_drop_transaction(journal_t *, transaction_t *); 767extern int cleanup_journal_tail(journal_t *); 768 769/* Reduce journal memory usage by flushing */ 770extern void shrink_journal_memory(void); 771 772/* Debugging code only: */ 773 774#define jbd_ENOSYS() \ 775do { \ 776 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \ 777 current->state = TASK_UNINTERRUPTIBLE; \ 778 schedule(); \ 779} while (1) 780 781/* 782 * is_journal_abort 783 * 784 * Simple test wrapper function to test the JFS_ABORT state flag. This 785 * bit, when set, indicates that we have had a fatal error somewhere, 786 * either inside the journaling layer or indicated to us by the client 787 * (eg. ext3), and that we and should not commit any further 788 * transactions. 789 */ 790 791static inline int is_journal_aborted(journal_t *journal) 792{ 793 return journal->j_flags & JFS_ABORT; 794} 795 796static inline int is_handle_aborted(handle_t *handle) 797{ 798 if (handle->h_aborted) 799 return 1; 800 return is_journal_aborted(handle->h_transaction->t_journal); 801} 802 803static inline void journal_abort_handle(handle_t *handle) 804{ 805 handle->h_aborted = 1; 806} 807 808/* Not all architectures define BUG() */ 809#ifndef BUG 810#define BUG() do { \ 811 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \ 812 * ((char *) 0) = 0; \ 813 } while (0) 814#endif /* BUG */ 815 816#else 817 818extern int journal_recover (journal_t *journal); 819extern int journal_skip_recovery (journal_t *); 820 821/* Primary revoke support */ 822extern int journal_init_revoke(journal_t *, int); 823extern void journal_destroy_revoke_caches(void); 824extern int journal_init_revoke_caches(void); 825 826/* Recovery revoke support */ 827extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 828extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 829extern void journal_clear_revoke(journal_t *); 830extern void journal_brelse_array(struct buffer_head *b[], int n); 831 832extern void journal_destroy_revoke(journal_t *); 833#endif /* __KERNEL__ */ 834 835static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 836static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 837 838/* Comparison functions for transaction IDs: perform comparisons using 839 * modulo arithmetic so that they work over sequence number wraps. */ 840 841static inline int tid_gt(tid_t x, tid_t y) 842{ 843 int difference = (x - y); 844 return (difference > 0); 845} 846 847static inline int tid_geq(tid_t x, tid_t y) 848{ 849 int difference = (x - y); 850 return (difference >= 0); 851} 852 853extern int journal_blocks_per_page(struct inode *inode); 854 855/* 856 * Definitions which augment the buffer_head layer 857 */ 858 859/* journaling buffer types */ 860#define BJ_None 0 /* Not journaled */ 861#define BJ_SyncData 1 /* Normal data: flush before commit */ 862#define BJ_AsyncData 2 /* writepage data: wait on it before commit */ 863#define BJ_Metadata 3 /* Normal journaled metadata */ 864#define BJ_Forget 4 /* Buffer superceded by this transaction */ 865#define BJ_IO 5 /* Buffer is for temporary IO use */ 866#define BJ_Shadow 6 /* Buffer contents being shadowed to the log */ 867#define BJ_LogCtl 7 /* Buffer contains log descriptors */ 868#define BJ_Reserved 8 /* Buffer is reserved for access by journal */ 869#define BJ_Types 9 870 871extern int jbd_blocks_per_page(struct inode *inode); 872 873#ifdef __KERNEL__ 874 875extern spinlock_t jh_splice_lock; 876/* 877 * Once `expr1' has been found true, take jh_splice_lock 878 * and then reevaluate everything. 879 */ 880#define SPLICE_LOCK(expr1, expr2) \ 881 ({ \ 882 int ret = (expr1); \ 883 if (ret) { \ 884 spin_lock(&jh_splice_lock); \ 885 ret = (expr1) && (expr2); \ 886 spin_unlock(&jh_splice_lock); \ 887 } \ 888 ret; \ 889 }) 890 891/* 892 * A number of buffer state predicates. They test for 893 * buffer_jbd() because they are used in core kernel code. 894 * 895 * These will be racy on SMP unless we're *sure* that the 896 * buffer won't be detached from the journalling system 897 * in parallel. 898 */ 899 900/* Return true if the buffer is on journal list `list' */ 901static inline int buffer_jlist_eq(struct buffer_head *bh, int list) 902{ 903 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list); 904} 905 906/* Return true if this bufer is dirty wrt the journal */ 907static inline int buffer_jdirty(struct buffer_head *bh) 908{ 909 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty); 910} 911 912/* Return true if it's a data buffer which journalling is managing */ 913static inline int buffer_jbd_data(struct buffer_head *bh) 914{ 915 return SPLICE_LOCK(buffer_jbd(bh), 916 bh2jh(bh)->b_jlist == BJ_SyncData || 917 bh2jh(bh)->b_jlist == BJ_AsyncData); 918} 919 920#ifdef CONFIG_SMP 921#define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock)) 922#else 923#define assert_spin_locked(lock) do {} while(0) 924#endif 925 926#define buffer_trace_init(bh) do {} while (0) 927#define print_buffer_fields(bh) do {} while (0) 928#define print_buffer_trace(bh) do {} while (0) 929#define BUFFER_TRACE(bh, info) do {} while (0) 930#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 931#define JBUFFER_TRACE(jh, info) do {} while (0) 932 933#endif /* __KERNEL__ */ 934 935#endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */ 936 937/* 938 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD 939 * go here. 940 */ 941 942#if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE)) 943 944#define J_ASSERT(expr) do {} while (0) 945#define J_ASSERT_BH(bh, expr) do {} while (0) 946#define buffer_jbd(bh) 0 947#define buffer_jlist_eq(bh, val) 0 948#define journal_buffer_journal_lru(bh) 0 949 950#endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */ 951#endif /* _LINUX_JBD_H */ 952