1 /* 2 * linux/include/linux/jbd.h 3 * 4 * Written by Stephen C. Tweedie <sct (at) 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 47 extern 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 68 extern 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__ 77 typedef struct handle_s handle_t; /* Atomic operation type */ 78 typedef 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 */ 104 typedef 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 */ 124 struct 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 */ 139 typedef 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 */ 153 typedef 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 */ 170 typedef 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 & ext2fs_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 & ext2fs_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 & ext2fs_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 JFS_FEATURE_INCOMPAT_64BIT) 239 240 #ifdef __KERNEL__ 241 242 #include <linux/fs.h> 243 #include <linux/sched.h> 244 245 #define JBD_ASSERTIONS 246 #ifdef JBD_ASSERTIONS 247 #define J_ASSERT(assert) \ 248 do { \ 249 if (!(assert)) { \ 250 printk (KERN_EMERG \ 251 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 252 __FUNCTION__, __FILE__, __LINE__, # assert); \ 253 BUG(); \ 254 } \ 255 } while (0) 256 257 #if defined(CONFIG_BUFFER_DEBUG) 258 void buffer_assertion_failure(struct buffer_head *bh); 259 #define J_ASSERT_BH(bh, expr) \ 260 do { \ 261 if (!(expr)) \ 262 buffer_assertion_failure(bh); \ 263 J_ASSERT(expr); \ 264 } while (0) 265 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 266 #else 267 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 268 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 269 #endif 270 271 #else 272 #define J_ASSERT(assert) 273 #endif /* JBD_ASSERTIONS */ 274 275 enum jbd_state_bits { 276 BH_JWrite 277 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */ 278 BH_Freed, /* 1 if buffer has been freed (truncated) */ 279 BH_Revoked, /* 1 if buffer has been revoked from the log */ 280 BH_RevokeValid, /* 1 if buffer revoked flag is valid */ 281 BH_JBDDirty, /* 1 if buffer is dirty but journaled */ 282 }; 283 284 /* Return true if the buffer is one which JBD is managing */ 285 static inline int buffer_jbd(struct buffer_head *bh) 286 { 287 return __buffer_state(bh, JBD); 288 } 289 290 static inline struct buffer_head *jh2bh(struct journal_head *jh) 291 { 292 return jh->b_bh; 293 } 294 295 static inline struct journal_head *bh2jh(struct buffer_head *bh) 296 { 297 return bh->b_private; 298 } 299 300 struct jbd_revoke_table_s; 301 302 /* The handle_t type represents a single atomic update being performed 303 * by some process. All filesystem modifications made by the process go 304 * through this handle. Recursive operations (such as quota operations) 305 * are gathered into a single update. 306 * 307 * The buffer credits field is used to account for journaled buffers 308 * being modified by the running process. To ensure that there is 309 * enough log space for all outstanding operations, we need to limit the 310 * number of outstanding buffers possible at any time. When the 311 * operation completes, any buffer credits not used are credited back to 312 * the transaction, so that at all times we know how many buffers the 313 * outstanding updates on a transaction might possibly touch. */ 314 315 struct handle_s 316 { 317 /* Which compound transaction is this update a part of? */ 318 transaction_t * h_transaction; 319 320 /* Number of remaining buffers we are allowed to dirty: */ 321 int h_buffer_credits; 322 323 /* Reference count on this handle */ 324 int h_ref; 325 326 /* Field for caller's use to track errors through large fs 327 operations */ 328 int h_err; 329 330 /* Flags */ 331 unsigned int h_sync: 1; /* sync-on-close */ 332 unsigned int h_jdata: 1; /* force data journaling */ 333 unsigned int h_aborted: 1; /* fatal error on handle */ 334 }; 335 336 337 /* The transaction_t type is the guts of the journaling mechanism. It 338 * tracks a compound transaction through its various states: 339 * 340 * RUNNING: accepting new updates 341 * LOCKED: Updates still running but we don't accept new ones 342 * RUNDOWN: Updates are tidying up but have finished requesting 343 * new buffers to modify (state not used for now) 344 * FLUSH: All updates complete, but we are still writing to disk 345 * COMMIT: All data on disk, writing commit record 346 * FINISHED: We still have to keep the transaction for checkpointing. 347 * 348 * The transaction keeps track of all of the buffers modified by a 349 * running transaction, and all of the buffers committed but not yet 350 * flushed to home for finished transactions. 351 */ 352 353 struct transaction_s 354 { 355 /* Pointer to the journal for this transaction. */ 356 journal_t * t_journal; 357 358 /* Sequence number for this transaction */ 359 tid_t t_tid; 360 361 /* Transaction's current state */ 362 enum { 363 T_RUNNING, 364 T_LOCKED, 365 T_RUNDOWN, 366 T_FLUSH, 367 T_COMMIT, 368 T_FINISHED 369 } t_state; 370 371 /* Where in the log does this transaction's commit start? */ 372 unsigned long t_log_start; 373 374 /* Doubly-linked circular list of all inodes owned by this 375 transaction */ /* AKPM: unused */ 376 struct inode * t_ilist; 377 378 /* Number of buffers on the t_buffers list */ 379 int t_nr_buffers; 380 381 /* Doubly-linked circular list of all buffers reserved but not 382 yet modified by this transaction */ 383 struct journal_head * t_reserved_list; 384 385 /* Doubly-linked circular list of all metadata buffers owned by this 386 transaction */ 387 struct journal_head * t_buffers; 388 389 /* 390 * Doubly-linked circular list of all data buffers still to be 391 * flushed before this transaction can be committed. 392 * Protected by journal_datalist_lock. 393 */ 394 struct journal_head * t_sync_datalist; 395 396 /* 397 * Doubly-linked circular list of all writepage data buffers 398 * still to be written before this transaction can be committed. 399 * Protected by journal_datalist_lock. 400 */ 401 struct journal_head * t_async_datalist; 402 403 /* Doubly-linked circular list of all forget buffers (superceded 404 buffers which we can un-checkpoint once this transaction 405 commits) */ 406 struct journal_head * t_forget; 407 408 /* 409 * Doubly-linked circular list of all buffers still to be 410 * flushed before this transaction can be checkpointed. 411 */ 412 /* Protected by journal_datalist_lock */ 413 struct journal_head * t_checkpoint_list; 414 415 /* Doubly-linked circular list of temporary buffers currently 416 undergoing IO in the log */ 417 struct journal_head * t_iobuf_list; 418 419 /* Doubly-linked circular list of metadata buffers being 420 shadowed by log IO. The IO buffers on the iobuf list and the 421 shadow buffers on this list match each other one for one at 422 all times. */ 423 struct journal_head * t_shadow_list; 424 425 /* Doubly-linked circular list of control buffers being written 426 to the log. */ 427 struct journal_head * t_log_list; 428 429 /* Number of outstanding updates running on this transaction */ 430 int t_updates; 431 432 /* Number of buffers reserved for use by all handles in this 433 * transaction handle but not yet modified. */ 434 int t_outstanding_credits; 435 436 /* 437 * Forward and backward links for the circular list of all 438 * transactions awaiting checkpoint. 439 */ 440 /* Protected by journal_datalist_lock */ 441 transaction_t *t_cpnext, *t_cpprev; 442 443 /* When will the transaction expire (become due for commit), in 444 * jiffies ? */ 445 unsigned long t_expires; 446 447 /* How many handles used this transaction? */ 448 int t_handle_count; 449 }; 450 451 452 /* The journal_t maintains all of the journaling state information for a 453 * single filesystem. It is linked to from the fs superblock structure. 454 * 455 * We use the journal_t to keep track of all outstanding transaction 456 * activity on the filesystem, and to manage the state of the log 457 * writing process. */ 458 459 struct journal_s 460 { 461 /* General journaling state flags */ 462 unsigned long j_flags; 463 464 /* Is there an outstanding uncleared error on the journal (from 465 * a prior abort)? */ 466 int j_errno; 467 468 /* The superblock buffer */ 469 struct buffer_head * j_sb_buffer; 470 journal_superblock_t * j_superblock; 471 472 /* Version of the superblock format */ 473 int j_format_version; 474 475 /* Number of processes waiting to create a barrier lock */ 476 int j_barrier_count; 477 478 /* The barrier lock itself */ 479 struct semaphore j_barrier; 480 481 /* Transactions: The current running transaction... */ 482 transaction_t * j_running_transaction; 483 484 /* ... the transaction we are pushing to disk ... */ 485 transaction_t * j_committing_transaction; 486 487 /* ... and a linked circular list of all transactions waiting 488 * for checkpointing. */ 489 /* Protected by journal_datalist_lock */ 490 transaction_t * j_checkpoint_transactions; 491 492 /* Wait queue for waiting for a locked transaction to start 493 committing, or for a barrier lock to be released */ 494 wait_queue_head_t j_wait_transaction_locked; 495 496 /* Wait queue for waiting for checkpointing to complete */ 497 wait_queue_head_t j_wait_logspace; 498 499 /* Wait queue for waiting for commit to complete */ 500 wait_queue_head_t j_wait_done_commit; 501 502 /* Wait queue to trigger checkpointing */ 503 wait_queue_head_t j_wait_checkpoint; 504 505 /* Wait queue to trigger commit */ 506 wait_queue_head_t j_wait_commit; 507 508 /* Wait queue to wait for updates to complete */ 509 wait_queue_head_t j_wait_updates; 510 511 /* Semaphore for locking against concurrent checkpoints */ 512 struct semaphore j_checkpoint_sem; 513 514 /* The main journal lock, used by lock_journal() */ 515 struct semaphore j_sem; 516 517 /* Journal head: identifies the first unused block in the journal. */ 518 unsigned long j_head; 519 520 /* Journal tail: identifies the oldest still-used block in the 521 * journal. */ 522 unsigned long j_tail; 523 524 /* Journal free: how many free blocks are there in the journal? */ 525 unsigned long j_free; 526 527 /* Journal start and end: the block numbers of the first usable 528 * block and one beyond the last usable block in the journal. */ 529 unsigned long j_first, j_last; 530 531 /* Device, blocksize and starting block offset for the location 532 * where we store the journal. */ 533 kdev_t j_dev; 534 int j_blocksize; 535 unsigned int j_blk_offset; 536 537 /* Device which holds the client fs. For internal journal this 538 * will be equal to j_dev. */ 539 kdev_t j_fs_dev; 540 541 /* Total maximum capacity of the journal region on disk. */ 542 unsigned int j_maxlen; 543 544 /* Optional inode where we store the journal. If present, all 545 * journal block numbers are mapped into this inode via 546 * bmap(). */ 547 struct inode * j_inode; 548 549 /* Sequence number of the oldest transaction in the log */ 550 tid_t j_tail_sequence; 551 /* Sequence number of the next transaction to grant */ 552 tid_t j_transaction_sequence; 553 /* Sequence number of the most recently committed transaction */ 554 tid_t j_commit_sequence; 555 /* Sequence number of the most recent transaction wanting commit */ 556 tid_t j_commit_request; 557 558 /* Journal uuid: identifies the object (filesystem, LVM volume 559 * etc) backed by this journal. This will eventually be 560 * replaced by an array of uuids, allowing us to index multiple 561 * devices within a single journal and to perform atomic updates 562 * across them. */ 563 564 __u8 j_uuid[16]; 565 566 /* Pointer to the current commit thread for this journal */ 567 struct task_struct * j_task; 568 569 /* Maximum number of metadata buffers to allow in a single 570 * compound commit transaction */ 571 int j_max_transaction_buffers; 572 573 /* What is the maximum transaction lifetime before we begin a 574 * commit? */ 575 unsigned long j_commit_interval; 576 577 /* The timer used to wakeup the commit thread: */ 578 struct timer_list * j_commit_timer; 579 int j_commit_timer_active; 580 581 /* Link all journals together - system-wide */ 582 struct list_head j_all_journals; 583 584 /* The revoke table: maintains the list of revoked blocks in the 585 current transaction. */ 586 struct jbd_revoke_table_s *j_revoke; 587 588 /* Failed journal commit ID */ 589 unsigned int j_failed_commit; 590 }; 591 592 /* 593 * Journal flag definitions 594 */ 595 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 596 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 597 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 598 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 599 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 600 601 /* 602 * Function declarations for the journaling transaction and buffer 603 * management 604 */ 605 606 /* Filing buffers */ 607 extern void __journal_unfile_buffer(struct journal_head *); 608 extern void journal_unfile_buffer(struct journal_head *); 609 extern void __journal_refile_buffer(struct journal_head *); 610 extern void journal_refile_buffer(struct journal_head *); 611 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 612 extern void __journal_free_buffer(struct journal_head *bh); 613 extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 614 extern void __journal_clean_data_list(transaction_t *transaction); 615 616 /* Log buffer allocation */ 617 extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 618 extern unsigned long journal_next_log_block(journal_t *); 619 620 /* Commit management */ 621 extern void journal_commit_transaction(journal_t *); 622 623 /* Checkpoint list management */ 624 int __journal_clean_checkpoint_list(journal_t *journal); 625 extern void journal_remove_checkpoint(struct journal_head *); 626 extern void __journal_remove_checkpoint(struct journal_head *); 627 extern void journal_insert_checkpoint(struct journal_head *, transaction_t *); 628 extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *); 629 630 /* Buffer IO */ 631 extern int 632 journal_write_metadata_buffer(transaction_t *transaction, 633 struct journal_head *jh_in, 634 struct journal_head **jh_out, 635 int blocknr); 636 637 /* Transaction locking */ 638 extern void __wait_on_journal (journal_t *); 639 640 /* 641 * Journal locking. 642 * 643 * We need to lock the journal during transaction state changes so that 644 * nobody ever tries to take a handle on the running transaction while 645 * we are in the middle of moving it to the commit phase. 646 * 647 * Note that the locking is completely interrupt unsafe. We never touch 648 * journal structures from interrupts. 649 * 650 * In 2.2, the BKL was required for lock_journal. This is no longer 651 * the case. 652 */ 653 654 static inline void lock_journal(journal_t *journal) 655 { 656 down(&journal->j_sem); 657 } 658 659 /* This returns zero if we acquired the semaphore */ 660 static inline int try_lock_journal(journal_t * journal) 661 { 662 return down_trylock(&journal->j_sem); 663 } 664 665 static inline void unlock_journal(journal_t * journal) 666 { 667 up(&journal->j_sem); 668 } 669 670 671 static inline handle_t *journal_current_handle(void) 672 { 673 return current->journal_info; 674 } 675 676 /* The journaling code user interface: 677 * 678 * Create and destroy handles 679 * Register buffer modifications against the current transaction. 680 */ 681 682 extern handle_t *journal_start(journal_t *, int nblocks); 683 extern handle_t *journal_try_start(journal_t *, int nblocks); 684 extern int journal_restart (handle_t *, int nblocks); 685 extern int journal_extend (handle_t *, int nblocks); 686 extern int journal_get_write_access (handle_t *, struct buffer_head *); 687 extern int journal_get_create_access (handle_t *, struct buffer_head *); 688 extern int journal_get_undo_access (handle_t *, struct buffer_head *); 689 extern int journal_dirty_data (handle_t *, 690 struct buffer_head *, int async); 691 extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 692 extern void journal_release_buffer (handle_t *, struct buffer_head *); 693 extern void journal_forget (handle_t *, struct buffer_head *); 694 extern void journal_sync_buffer (struct buffer_head *); 695 extern int journal_flushpage(journal_t *, struct page *, unsigned long); 696 extern int journal_try_to_free_buffers(journal_t *, struct page *, int); 697 extern int journal_stop(handle_t *); 698 extern int journal_flush (journal_t *); 699 700 extern void journal_lock_updates (journal_t *); 701 extern void journal_unlock_updates (journal_t *); 702 703 extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev, 704 int start, int len, int bsize); 705 extern journal_t * journal_init_inode (struct inode *); 706 extern int journal_update_format (journal_t *); 707 extern int journal_check_used_features 708 (journal_t *, unsigned long, unsigned long, unsigned long); 709 extern int journal_check_available_features 710 (journal_t *, unsigned long, unsigned long, unsigned long); 711 extern int journal_set_features 712 (journal_t *, unsigned long, unsigned long, unsigned long); 713 extern int journal_create (journal_t *); 714 extern int journal_load (journal_t *journal); 715 extern void journal_destroy (journal_t *); 716 extern int journal_recover (journal_t *journal); 717 extern int journal_wipe (journal_t *, int); 718 extern int journal_skip_recovery (journal_t *); 719 extern void journal_update_superblock (journal_t *, int); 720 extern void __journal_abort (journal_t *); 721 extern void journal_abort (journal_t *, int); 722 extern int journal_errno (journal_t *); 723 extern void journal_ack_err (journal_t *); 724 extern int journal_clear_err (journal_t *); 725 extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr); 726 extern int journal_force_commit(journal_t *journal); 727 728 /* 729 * journal_head management 730 */ 731 extern struct journal_head 732 *journal_add_journal_head(struct buffer_head *bh); 733 extern void journal_remove_journal_head(struct buffer_head *bh); 734 extern void __journal_remove_journal_head(struct buffer_head *bh); 735 extern void journal_unlock_journal_head(struct journal_head *jh); 736 737 /* Primary revoke support */ 738 #define JOURNAL_REVOKE_DEFAULT_HASH 256 739 extern int journal_init_revoke(journal_t *, int); 740 extern void journal_destroy_revoke_caches(void); 741 extern int journal_init_revoke_caches(void); 742 743 extern void journal_destroy_revoke(journal_t *); 744 extern int journal_revoke (handle_t *, 745 unsigned long, struct buffer_head *); 746 extern int journal_cancel_revoke(handle_t *, struct journal_head *); 747 extern void journal_write_revoke_records(journal_t *, transaction_t *); 748 749 /* Recovery revoke support */ 750 extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 751 extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 752 extern void journal_clear_revoke(journal_t *); 753 extern void journal_brelse_array(struct buffer_head *b[], int n); 754 755 /* The log thread user interface: 756 * 757 * Request space in the current transaction, and force transaction commit 758 * transitions on demand. 759 */ 760 761 extern int log_space_left (journal_t *); /* Called with journal locked */ 762 extern tid_t log_start_commit (journal_t *, transaction_t *); 763 extern void log_wait_commit (journal_t *, tid_t); 764 extern int log_do_checkpoint (journal_t *, int); 765 766 extern void log_wait_for_space(journal_t *, int nblocks); 767 extern void __journal_drop_transaction(journal_t *, transaction_t *); 768 extern int cleanup_journal_tail(journal_t *); 769 770 /* Reduce journal memory usage by flushing */ 771 extern void shrink_journal_memory(void); 772 773 /* Debugging code only: */ 774 775 #define jbd_ENOSYS() \ 776 do { \ 777 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \ 778 current->state = TASK_UNINTERRUPTIBLE; \ 779 schedule(); \ 780 } while (1) 781 782 /* 783 * is_journal_abort 784 * 785 * Simple test wrapper function to test the JFS_ABORT state flag. This 786 * bit, when set, indicates that we have had a fatal error somewhere, 787 * either inside the journaling layer or indicated to us by the client 788 * (eg. ext3), and that we and should not commit any further 789 * transactions. 790 */ 791 792 static inline int is_journal_aborted(journal_t *journal) 793 { 794 return journal->j_flags & JFS_ABORT; 795 } 796 797 static inline int is_handle_aborted(handle_t *handle) 798 { 799 if (handle->h_aborted) 800 return 1; 801 return is_journal_aborted(handle->h_transaction->t_journal); 802 } 803 804 static inline void journal_abort_handle(handle_t *handle) 805 { 806 handle->h_aborted = 1; 807 } 808 809 /* Not all architectures define BUG() */ 810 #ifndef BUG 811 #define BUG() do { \ 812 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \ 813 * ((char *) 0) = 0; \ 814 } while (0) 815 #endif /* BUG */ 816 817 #else 818 819 extern int journal_recover (journal_t *journal); 820 extern int journal_skip_recovery (journal_t *); 821 822 /* Primary revoke support */ 823 extern int journal_init_revoke(journal_t *, int); 824 extern void journal_destroy_revoke_caches(void); 825 extern int journal_init_revoke_caches(void); 826 827 /* Recovery revoke support */ 828 extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 829 extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 830 extern void journal_clear_revoke(journal_t *); 831 extern void journal_brelse_array(struct buffer_head *b[], int n); 832 833 extern void journal_destroy_revoke(journal_t *); 834 #endif /* __KERNEL__ */ 835 836 static inline int tid_gt(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 837 static inline int tid_geq(tid_t x, tid_t y) EXT2FS_ATTR((unused)); 838 839 /* Comparison functions for transaction IDs: perform comparisons using 840 * modulo arithmetic so that they work over sequence number wraps. */ 841 842 static inline int tid_gt(tid_t x, tid_t y) 843 { 844 int difference = (x - y); 845 return (difference > 0); 846 } 847 848 static inline int tid_geq(tid_t x, tid_t y) 849 { 850 int difference = (x - y); 851 return (difference >= 0); 852 } 853 854 extern int journal_blocks_per_page(struct inode *inode); 855 856 /* 857 * Definitions which augment the buffer_head layer 858 */ 859 860 /* journaling buffer types */ 861 #define BJ_None 0 /* Not journaled */ 862 #define BJ_SyncData 1 /* Normal data: flush before commit */ 863 #define BJ_AsyncData 2 /* writepage data: wait on it before commit */ 864 #define BJ_Metadata 3 /* Normal journaled metadata */ 865 #define BJ_Forget 4 /* Buffer superceded by this transaction */ 866 #define BJ_IO 5 /* Buffer is for temporary IO use */ 867 #define BJ_Shadow 6 /* Buffer contents being shadowed to the log */ 868 #define BJ_LogCtl 7 /* Buffer contains log descriptors */ 869 #define BJ_Reserved 8 /* Buffer is reserved for access by journal */ 870 #define BJ_Types 9 871 872 extern int jbd_blocks_per_page(struct inode *inode); 873 874 #ifdef __KERNEL__ 875 876 extern spinlock_t jh_splice_lock; 877 /* 878 * Once `expr1' has been found true, take jh_splice_lock 879 * and then reevaluate everything. 880 */ 881 #define SPLICE_LOCK(expr1, expr2) \ 882 ({ \ 883 int ret = (expr1); \ 884 if (ret) { \ 885 spin_lock(&jh_splice_lock); \ 886 ret = (expr1) && (expr2); \ 887 spin_unlock(&jh_splice_lock); \ 888 } \ 889 ret; \ 890 }) 891 892 /* 893 * A number of buffer state predicates. They test for 894 * buffer_jbd() because they are used in core kernel code. 895 * 896 * These will be racy on SMP unless we're *sure* that the 897 * buffer won't be detached from the journalling system 898 * in parallel. 899 */ 900 901 /* Return true if the buffer is on journal list `list' */ 902 static inline int buffer_jlist_eq(struct buffer_head *bh, int list) 903 { 904 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list); 905 } 906 907 /* Return true if this bufer is dirty wrt the journal */ 908 static inline int buffer_jdirty(struct buffer_head *bh) 909 { 910 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty); 911 } 912 913 /* Return true if it's a data buffer which journalling is managing */ 914 static inline int buffer_jbd_data(struct buffer_head *bh) 915 { 916 return SPLICE_LOCK(buffer_jbd(bh), 917 bh2jh(bh)->b_jlist == BJ_SyncData || 918 bh2jh(bh)->b_jlist == BJ_AsyncData); 919 } 920 921 #ifdef CONFIG_SMP 922 #define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock)) 923 #else 924 #define assert_spin_locked(lock) do {} while(0) 925 #endif 926 927 #define buffer_trace_init(bh) do {} while (0) 928 #define print_buffer_fields(bh) do {} while (0) 929 #define print_buffer_trace(bh) do {} while (0) 930 #define BUFFER_TRACE(bh, info) do {} while (0) 931 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 932 #define JBUFFER_TRACE(jh, info) do {} while (0) 933 934 #endif /* __KERNEL__ */ 935 936 #endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */ 937 938 /* 939 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD 940 * go here. 941 */ 942 943 #if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE)) 944 945 #define J_ASSERT(expr) do {} while (0) 946 #define J_ASSERT_BH(bh, expr) do {} while (0) 947 #define buffer_jbd(bh) 0 948 #define buffer_jlist_eq(bh, val) 0 949 #define journal_buffer_journal_lru(bh) 0 950 951 #endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */ 952 #endif /* _LINUX_JBD_H */ 953
