1/* 2 * linux/include/linux/jbd.h 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16#ifndef _LINUX_JBD_H 17#define _LINUX_JBD_H 18 19/* Allow this file to be included directly into e2fsprogs */ 20#ifndef __KERNEL__ 21#include "jfs_compat.h" 22#define JFS_DEBUG 23#define jfs_debug jbd_debug 24#else 25 26#include <linux/types.h> 27#include <linux/buffer_head.h> 28#include <linux/journal-head.h> 29#include <linux/stddef.h> 30#include <linux/mutex.h> 31#include <linux/timer.h> 32#include <linux/lockdep.h> 33#include <linux/slab.h> 34 35#define journal_oom_retry 1 36 37/* 38 * Define JBD_PARANOID_IOFAIL to cause a kernel BUG() if ext3 finds 39 * certain classes of error which can occur due to failed IOs. Under 40 * normal use we want ext3 to continue after such errors, because 41 * hardware _can_ fail, but for debugging purposes when running tests on 42 * known-good hardware we may want to trap these errors. 43 */ 44#undef JBD_PARANOID_IOFAIL 45 46/* 47 * The default maximum commit age, in seconds. 48 */ 49#define JBD_DEFAULT_MAX_COMMIT_AGE 5 50 51#ifdef CONFIG_JBD_DEBUG 52/* 53 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal 54 * consistency checks. By default we don't do this unless 55 * CONFIG_JBD_DEBUG is on. 56 */ 57#define JBD_EXPENSIVE_CHECKING 58extern u8 journal_enable_debug; 59 60void __jbd_debug(int level, const char *file, const char *func, 61 unsigned int line, const char *fmt, ...); 62 63#define jbd_debug(n, fmt, a...) \ 64 __jbd_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a) 65#else 66#define jbd_debug(n, fmt, a...) /**/ 67#endif 68 69static inline void *jbd_alloc(size_t size, gfp_t flags) 70{ 71 return (void *)__get_free_pages(flags, get_order(size)); 72} 73 74static inline void jbd_free(void *ptr, size_t size) 75{ 76 free_pages((unsigned long)ptr, get_order(size)); 77} 78 79#define JFS_MIN_JOURNAL_BLOCKS 1024 80 81 82/** 83 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 84 * 85 * All filesystem modifications made by the process go 86 * through this handle. Recursive operations (such as quota operations) 87 * are gathered into a single update. 88 * 89 * The buffer credits field is used to account for journaled buffers 90 * being modified by the running process. To ensure that there is 91 * enough log space for all outstanding operations, we need to limit the 92 * number of outstanding buffers possible at any time. When the 93 * operation completes, any buffer credits not used are credited back to 94 * the transaction, so that at all times we know how many buffers the 95 * outstanding updates on a transaction might possibly touch. 96 * 97 * This is an opaque datatype. 98 **/ 99typedef struct handle_s handle_t; /* Atomic operation type */ 100 101 102/** 103 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 104 * 105 * journal_t is linked to from the fs superblock structure. 106 * 107 * We use the journal_t to keep track of all outstanding transaction 108 * activity on the filesystem, and to manage the state of the log 109 * writing process. 110 * 111 * This is an opaque datatype. 112 **/ 113typedef struct journal_s journal_t; /* Journal control structure */ 114#endif 115 116/* 117 * Internal structures used by the logging mechanism: 118 */ 119 120#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 121 122/* 123 * On-disk structures 124 */ 125 126/* 127 * Descriptor block types: 128 */ 129 130#define JFS_DESCRIPTOR_BLOCK 1 131#define JFS_COMMIT_BLOCK 2 132#define JFS_SUPERBLOCK_V1 3 133#define JFS_SUPERBLOCK_V2 4 134#define JFS_REVOKE_BLOCK 5 135 136/* 137 * Standard header for all descriptor blocks: 138 */ 139typedef struct journal_header_s 140{ 141 __be32 h_magic; 142 __be32 h_blocktype; 143 __be32 h_sequence; 144} journal_header_t; 145 146 147/* 148 * The block tag: used to describe a single buffer in the journal 149 */ 150typedef struct journal_block_tag_s 151{ 152 __be32 t_blocknr; /* The on-disk block number */ 153 __be32 t_flags; /* See below */ 154} journal_block_tag_t; 155 156/* 157 * The revoke descriptor: used on disk to describe a series of blocks to 158 * be revoked from the log 159 */ 160typedef struct journal_revoke_header_s 161{ 162 journal_header_t r_header; 163 __be32 r_count; /* Count of bytes used in the block */ 164} journal_revoke_header_t; 165 166 167/* Definitions for the journal tag flags word: */ 168#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 169#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 170#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 171#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 172 173 174/* 175 * The journal superblock. All fields are in big-endian byte order. 176 */ 177typedef struct journal_superblock_s 178{ 179/* 0x0000 */ 180 journal_header_t s_header; 181 182/* 0x000C */ 183 /* Static information describing the journal */ 184 __be32 s_blocksize; /* journal device blocksize */ 185 __be32 s_maxlen; /* total blocks in journal file */ 186 __be32 s_first; /* first block of log information */ 187 188/* 0x0018 */ 189 /* Dynamic information describing the current state of the log */ 190 __be32 s_sequence; /* first commit ID expected in log */ 191 __be32 s_start; /* blocknr of start of log */ 192 193/* 0x0020 */ 194 /* Error value, as set by journal_abort(). */ 195 __be32 s_errno; 196 197/* 0x0024 */ 198 /* Remaining fields are only valid in a version-2 superblock */ 199 __be32 s_feature_compat; /* compatible feature set */ 200 __be32 s_feature_incompat; /* incompatible feature set */ 201 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 202/* 0x0030 */ 203 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 204 205/* 0x0040 */ 206 __be32 s_nr_users; /* Nr of filesystems sharing log */ 207 208 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 209 210/* 0x0048 */ 211 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 212 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 213 214/* 0x0050 */ 215 __u32 s_padding[44]; 216 217/* 0x0100 */ 218 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 219/* 0x0400 */ 220} journal_superblock_t; 221 222#define JFS_HAS_COMPAT_FEATURE(j,mask) \ 223 ((j)->j_format_version >= 2 && \ 224 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 225#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 226 ((j)->j_format_version >= 2 && \ 227 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 228#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 229 ((j)->j_format_version >= 2 && \ 230 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 231 232#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 233 234/* Features known to this kernel version: */ 235#define JFS_KNOWN_COMPAT_FEATURES 0 236#define JFS_KNOWN_ROCOMPAT_FEATURES 0 237#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE 238 239#ifdef __KERNEL__ 240 241#include <linux/fs.h> 242#include <linux/sched.h> 243 244enum jbd_state_bits { 245 BH_JBD /* Has an attached ext3 journal_head */ 246 = BH_PrivateStart, 247 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 248 BH_Freed, /* Has been freed (truncated) */ 249 BH_Revoked, /* Has been revoked from the log */ 250 BH_RevokeValid, /* Revoked flag is valid */ 251 BH_JBDDirty, /* Is dirty but journaled */ 252 BH_State, /* Pins most journal_head state */ 253 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 254 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 255 BH_JBDPrivateStart, /* First bit available for private use by FS */ 256}; 257 258BUFFER_FNS(JBD, jbd) 259BUFFER_FNS(JWrite, jwrite) 260BUFFER_FNS(JBDDirty, jbddirty) 261TAS_BUFFER_FNS(JBDDirty, jbddirty) 262BUFFER_FNS(Revoked, revoked) 263TAS_BUFFER_FNS(Revoked, revoked) 264BUFFER_FNS(RevokeValid, revokevalid) 265TAS_BUFFER_FNS(RevokeValid, revokevalid) 266BUFFER_FNS(Freed, freed) 267 268#include <linux/jbd_common.h> 269 270#define J_ASSERT(assert) BUG_ON(!(assert)) 271 272#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 273#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 274 275#if defined(JBD_PARANOID_IOFAIL) 276#define J_EXPECT(expr, why...) J_ASSERT(expr) 277#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 278#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 279#else 280#define __journal_expect(expr, why...) \ 281 ({ \ 282 int val = (expr); \ 283 if (!val) { \ 284 printk(KERN_ERR \ 285 "EXT3-fs unexpected failure: %s;\n",# expr); \ 286 printk(KERN_ERR why "\n"); \ 287 } \ 288 val; \ 289 }) 290#define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 291#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 292#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 293#endif 294 295struct jbd_revoke_table_s; 296 297/** 298 * struct handle_s - this is the concrete type associated with handle_t. 299 * @h_transaction: Which compound transaction is this update a part of? 300 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 301 * @h_ref: Reference count on this handle 302 * @h_err: Field for caller's use to track errors through large fs operations 303 * @h_sync: flag for sync-on-close 304 * @h_jdata: flag to force data journaling 305 * @h_aborted: flag indicating fatal error on handle 306 * @h_lockdep_map: lockdep info for debugging lock problems 307 */ 308struct handle_s 309{ 310 /* Which compound transaction is this update a part of? */ 311 transaction_t *h_transaction; 312 313 /* Number of remaining buffers we are allowed to dirty: */ 314 int h_buffer_credits; 315 316 /* Reference count on this handle */ 317 int h_ref; 318 319 /* Field for caller's use to track errors through large fs */ 320 /* operations */ 321 int h_err; 322 323 /* Flags [no locking] */ 324 unsigned int h_sync: 1; /* sync-on-close */ 325 unsigned int h_jdata: 1; /* force data journaling */ 326 unsigned int h_aborted: 1; /* fatal error on handle */ 327 328#ifdef CONFIG_DEBUG_LOCK_ALLOC 329 struct lockdep_map h_lockdep_map; 330#endif 331}; 332 333 334/* The transaction_t type is the guts of the journaling mechanism. It 335 * tracks a compound transaction through its various states: 336 * 337 * RUNNING: accepting new updates 338 * LOCKED: Updates still running but we don't accept new ones 339 * RUNDOWN: Updates are tidying up but have finished requesting 340 * new buffers to modify (state not used for now) 341 * FLUSH: All updates complete, but we are still writing to disk 342 * COMMIT: All data on disk, writing commit record 343 * FINISHED: We still have to keep the transaction for checkpointing. 344 * 345 * The transaction keeps track of all of the buffers modified by a 346 * running transaction, and all of the buffers committed but not yet 347 * flushed to home for finished transactions. 348 */ 349 350/* 351 * Lock ranking: 352 * 353 * j_list_lock 354 * ->jbd_lock_bh_journal_head() (This is "innermost") 355 * 356 * j_state_lock 357 * ->jbd_lock_bh_state() 358 * 359 * jbd_lock_bh_state() 360 * ->j_list_lock 361 * 362 * j_state_lock 363 * ->t_handle_lock 364 * 365 * j_state_lock 366 * ->j_list_lock (journal_unmap_buffer) 367 * 368 */ 369 370struct transaction_s 371{ 372 /* Pointer to the journal for this transaction. [no locking] */ 373 journal_t *t_journal; 374 375 /* Sequence number for this transaction [no locking] */ 376 tid_t t_tid; 377 378 /* 379 * Transaction's current state 380 * [no locking - only kjournald alters this] 381 * [j_list_lock] guards transition of a transaction into T_FINISHED 382 * state and subsequent call of __journal_drop_transaction() 383 * FIXME: needs barriers 384 * KLUDGE: [use j_state_lock] 385 */ 386 enum { 387 T_RUNNING, 388 T_LOCKED, 389 T_FLUSH, 390 T_COMMIT, 391 T_COMMIT_RECORD, 392 T_FINISHED 393 } t_state; 394 395 /* 396 * Where in the log does this transaction's commit start? [no locking] 397 */ 398 unsigned int t_log_start; 399 400 /* Number of buffers on the t_buffers list [j_list_lock] */ 401 int t_nr_buffers; 402 403 /* 404 * Doubly-linked circular list of all buffers reserved but not yet 405 * modified by this transaction [j_list_lock] 406 */ 407 struct journal_head *t_reserved_list; 408 409 /* 410 * Doubly-linked circular list of all buffers under writeout during 411 * commit [j_list_lock] 412 */ 413 struct journal_head *t_locked_list; 414 415 /* 416 * Doubly-linked circular list of all metadata buffers owned by this 417 * transaction [j_list_lock] 418 */ 419 struct journal_head *t_buffers; 420 421 /* 422 * Doubly-linked circular list of all data buffers still to be 423 * flushed before this transaction can be committed [j_list_lock] 424 */ 425 struct journal_head *t_sync_datalist; 426 427 /* 428 * Doubly-linked circular list of all forget buffers (superseded 429 * buffers which we can un-checkpoint once this transaction commits) 430 * [j_list_lock] 431 */ 432 struct journal_head *t_forget; 433 434 /* 435 * Doubly-linked circular list of all buffers still to be flushed before 436 * this transaction can be checkpointed. [j_list_lock] 437 */ 438 struct journal_head *t_checkpoint_list; 439 440 /* 441 * Doubly-linked circular list of all buffers submitted for IO while 442 * checkpointing. [j_list_lock] 443 */ 444 struct journal_head *t_checkpoint_io_list; 445 446 /* 447 * Doubly-linked circular list of temporary buffers currently undergoing 448 * IO in the log [j_list_lock] 449 */ 450 struct journal_head *t_iobuf_list; 451 452 /* 453 * Doubly-linked circular list of metadata buffers being shadowed by log 454 * IO. The IO buffers on the iobuf list and the shadow buffers on this 455 * list match each other one for one at all times. [j_list_lock] 456 */ 457 struct journal_head *t_shadow_list; 458 459 /* 460 * Doubly-linked circular list of control buffers being written to the 461 * log. [j_list_lock] 462 */ 463 struct journal_head *t_log_list; 464 465 /* 466 * Protects info related to handles 467 */ 468 spinlock_t t_handle_lock; 469 470 /* 471 * Number of outstanding updates running on this transaction 472 * [t_handle_lock] 473 */ 474 int t_updates; 475 476 /* 477 * Number of buffers reserved for use by all handles in this transaction 478 * handle but not yet modified. [t_handle_lock] 479 */ 480 int t_outstanding_credits; 481 482 /* 483 * Forward and backward links for the circular list of all transactions 484 * awaiting checkpoint. [j_list_lock] 485 */ 486 transaction_t *t_cpnext, *t_cpprev; 487 488 /* 489 * When will the transaction expire (become due for commit), in jiffies? 490 * [no locking] 491 */ 492 unsigned long t_expires; 493 494 /* 495 * When this transaction started, in nanoseconds [no locking] 496 */ 497 ktime_t t_start_time; 498 499 /* 500 * How many handles used this transaction? [t_handle_lock] 501 */ 502 int t_handle_count; 503}; 504 505/** 506 * struct journal_s - this is the concrete type associated with journal_t. 507 * @j_flags: General journaling state flags 508 * @j_errno: Is there an outstanding uncleared error on the journal (from a 509 * prior abort)? 510 * @j_sb_buffer: First part of superblock buffer 511 * @j_superblock: Second part of superblock buffer 512 * @j_format_version: Version of the superblock format 513 * @j_state_lock: Protect the various scalars in the journal 514 * @j_barrier_count: Number of processes waiting to create a barrier lock 515 * @j_running_transaction: The current running transaction.. 516 * @j_committing_transaction: the transaction we are pushing to disk 517 * @j_checkpoint_transactions: a linked circular list of all transactions 518 * waiting for checkpointing 519 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 520 * to start committing, or for a barrier lock to be released 521 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 522 * @j_wait_done_commit: Wait queue for waiting for commit to complete 523 * @j_wait_checkpoint: Wait queue to trigger checkpointing 524 * @j_wait_commit: Wait queue to trigger commit 525 * @j_wait_updates: Wait queue to wait for updates to complete 526 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 527 * @j_head: Journal head - identifies the first unused block in the journal 528 * @j_tail: Journal tail - identifies the oldest still-used block in the 529 * journal. 530 * @j_free: Journal free - how many free blocks are there in the journal? 531 * @j_first: The block number of the first usable block 532 * @j_last: The block number one beyond the last usable block 533 * @j_dev: Device where we store the journal 534 * @j_blocksize: blocksize for the location where we store the journal. 535 * @j_blk_offset: starting block offset for into the device where we store the 536 * journal 537 * @j_fs_dev: Device which holds the client fs. For internal journal this will 538 * be equal to j_dev 539 * @j_maxlen: Total maximum capacity of the journal region on disk. 540 * @j_list_lock: Protects the buffer lists and internal buffer state. 541 * @j_inode: Optional inode where we store the journal. If present, all journal 542 * block numbers are mapped into this inode via bmap(). 543 * @j_tail_sequence: Sequence number of the oldest transaction in the log 544 * @j_transaction_sequence: Sequence number of the next transaction to grant 545 * @j_commit_sequence: Sequence number of the most recently committed 546 * transaction 547 * @j_commit_request: Sequence number of the most recent transaction wanting 548 * commit 549 * @j_commit_waited: Sequence number of the most recent transaction someone 550 * is waiting for to commit. 551 * @j_uuid: Uuid of client object. 552 * @j_task: Pointer to the current commit thread for this journal 553 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 554 * single compound commit transaction 555 * @j_commit_interval: What is the maximum transaction lifetime before we begin 556 * a commit? 557 * @j_commit_timer: The timer used to wakeup the commit thread 558 * @j_revoke_lock: Protect the revoke table 559 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 560 * current transaction. 561 * @j_revoke_table: alternate revoke tables for j_revoke 562 * @j_wbuf: array of buffer_heads for journal_commit_transaction 563 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 564 * number that will fit in j_blocksize 565 * @j_last_sync_writer: most recent pid which did a synchronous write 566 * @j_average_commit_time: the average amount of time in nanoseconds it 567 * takes to commit a transaction to the disk. 568 * @j_private: An opaque pointer to fs-private information. 569 */ 570 571struct journal_s 572{ 573 /* General journaling state flags [j_state_lock] */ 574 unsigned long j_flags; 575 576 /* 577 * Is there an outstanding uncleared error on the journal (from a prior 578 * abort)? [j_state_lock] 579 */ 580 int j_errno; 581 582 /* The superblock buffer */ 583 struct buffer_head *j_sb_buffer; 584 journal_superblock_t *j_superblock; 585 586 /* Version of the superblock format */ 587 int j_format_version; 588 589 /* 590 * Protect the various scalars in the journal 591 */ 592 spinlock_t j_state_lock; 593 594 /* 595 * Number of processes waiting to create a barrier lock [j_state_lock] 596 */ 597 int j_barrier_count; 598 599 /* 600 * Transactions: The current running transaction... 601 * [j_state_lock] [caller holding open handle] 602 */ 603 transaction_t *j_running_transaction; 604 605 /* 606 * the transaction we are pushing to disk 607 * [j_state_lock] [caller holding open handle] 608 */ 609 transaction_t *j_committing_transaction; 610 611 /* 612 * ... and a linked circular list of all transactions waiting for 613 * checkpointing. [j_list_lock] 614 */ 615 transaction_t *j_checkpoint_transactions; 616 617 /* 618 * Wait queue for waiting for a locked transaction to start committing, 619 * or for a barrier lock to be released 620 */ 621 wait_queue_head_t j_wait_transaction_locked; 622 623 /* Wait queue for waiting for checkpointing to complete */ 624 wait_queue_head_t j_wait_logspace; 625 626 /* Wait queue for waiting for commit to complete */ 627 wait_queue_head_t j_wait_done_commit; 628 629 /* Wait queue to trigger checkpointing */ 630 wait_queue_head_t j_wait_checkpoint; 631 632 /* Wait queue to trigger commit */ 633 wait_queue_head_t j_wait_commit; 634 635 /* Wait queue to wait for updates to complete */ 636 wait_queue_head_t j_wait_updates; 637 638 /* Semaphore for locking against concurrent checkpoints */ 639 struct mutex j_checkpoint_mutex; 640 641 /* 642 * Journal head: identifies the first unused block in the journal. 643 * [j_state_lock] 644 */ 645 unsigned int j_head; 646 647 /* 648 * Journal tail: identifies the oldest still-used block in the journal. 649 * [j_state_lock] 650 */ 651 unsigned int j_tail; 652 653 /* 654 * Journal free: how many free blocks are there in the journal? 655 * [j_state_lock] 656 */ 657 unsigned int j_free; 658 659 /* 660 * Journal start and end: the block numbers of the first usable block 661 * and one beyond the last usable block in the journal. [j_state_lock] 662 */ 663 unsigned int j_first; 664 unsigned int j_last; 665 666 /* 667 * Device, blocksize and starting block offset for the location where we 668 * store the journal. 669 */ 670 struct block_device *j_dev; 671 int j_blocksize; 672 unsigned int j_blk_offset; 673 674 /* 675 * Device which holds the client fs. For internal journal this will be 676 * equal to j_dev. 677 */ 678 struct block_device *j_fs_dev; 679 680 /* Total maximum capacity of the journal region on disk. */ 681 unsigned int j_maxlen; 682 683 /* 684 * Protects the buffer lists and internal buffer state. 685 */ 686 spinlock_t j_list_lock; 687 688 /* Optional inode where we store the journal. If present, all */ 689 /* journal block numbers are mapped into this inode via */ 690 /* bmap(). */ 691 struct inode *j_inode; 692 693 /* 694 * Sequence number of the oldest transaction in the log [j_state_lock] 695 */ 696 tid_t j_tail_sequence; 697 698 /* 699 * Sequence number of the next transaction to grant [j_state_lock] 700 */ 701 tid_t j_transaction_sequence; 702 703 /* 704 * Sequence number of the most recently committed transaction 705 * [j_state_lock]. 706 */ 707 tid_t j_commit_sequence; 708 709 /* 710 * Sequence number of the most recent transaction wanting commit 711 * [j_state_lock] 712 */ 713 tid_t j_commit_request; 714 715 /* 716 * Sequence number of the most recent transaction someone is waiting 717 * for to commit. 718 * [j_state_lock] 719 */ 720 tid_t j_commit_waited; 721 722 /* 723 * Journal uuid: identifies the object (filesystem, LVM volume etc) 724 * backed by this journal. This will eventually be replaced by an array 725 * of uuids, allowing us to index multiple devices within a single 726 * journal and to perform atomic updates across them. 727 */ 728 __u8 j_uuid[16]; 729 730 /* Pointer to the current commit thread for this journal */ 731 struct task_struct *j_task; 732 733 /* 734 * Maximum number of metadata buffers to allow in a single compound 735 * commit transaction 736 */ 737 int j_max_transaction_buffers; 738 739 /* 740 * What is the maximum transaction lifetime before we begin a commit? 741 */ 742 unsigned long j_commit_interval; 743 744 /* The timer used to wakeup the commit thread: */ 745 struct timer_list j_commit_timer; 746 747 /* 748 * The revoke table: maintains the list of revoked blocks in the 749 * current transaction. [j_revoke_lock] 750 */ 751 spinlock_t j_revoke_lock; 752 struct jbd_revoke_table_s *j_revoke; 753 struct jbd_revoke_table_s *j_revoke_table[2]; 754 755 /* 756 * array of bhs for journal_commit_transaction 757 */ 758 struct buffer_head **j_wbuf; 759 int j_wbufsize; 760 761 /* 762 * this is the pid of the last person to run a synchronous operation 763 * through the journal. 764 */ 765 pid_t j_last_sync_writer; 766 767 /* 768 * the average amount of time in nanoseconds it takes to commit a 769 * transaction to the disk. [j_state_lock] 770 */ 771 u64 j_average_commit_time; 772 773 /* 774 * An opaque pointer to fs-private information. ext3 puts its 775 * superblock pointer here 776 */ 777 void *j_private; 778}; 779 780/* 781 * Journal flag definitions 782 */ 783#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 784#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 785#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 786#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 787#define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 788#define JFS_BARRIER 0x020 /* Use IDE barriers */ 789#define JFS_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 790 * data write error in ordered 791 * mode */ 792 793/* 794 * Function declarations for the journaling transaction and buffer 795 * management 796 */ 797 798/* Filing buffers */ 799extern void journal_unfile_buffer(journal_t *, struct journal_head *); 800extern void __journal_unfile_buffer(struct journal_head *); 801extern void __journal_refile_buffer(struct journal_head *); 802extern void journal_refile_buffer(journal_t *, struct journal_head *); 803extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 804extern void __journal_free_buffer(struct journal_head *bh); 805extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 806extern void __journal_clean_data_list(transaction_t *transaction); 807 808/* Log buffer allocation */ 809extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 810int journal_next_log_block(journal_t *, unsigned int *); 811 812/* Commit management */ 813extern void journal_commit_transaction(journal_t *); 814 815/* Checkpoint list management */ 816int __journal_clean_checkpoint_list(journal_t *journal); 817int __journal_remove_checkpoint(struct journal_head *); 818void __journal_insert_checkpoint(struct journal_head *, transaction_t *); 819 820/* Buffer IO */ 821extern int 822journal_write_metadata_buffer(transaction_t *transaction, 823 struct journal_head *jh_in, 824 struct journal_head **jh_out, 825 unsigned int blocknr); 826 827/* Transaction locking */ 828extern void __wait_on_journal (journal_t *); 829 830/* 831 * Journal locking. 832 * 833 * We need to lock the journal during transaction state changes so that nobody 834 * ever tries to take a handle on the running transaction while we are in the 835 * middle of moving it to the commit phase. j_state_lock does this. 836 * 837 * Note that the locking is completely interrupt unsafe. We never touch 838 * journal structures from interrupts. 839 */ 840 841static inline handle_t *journal_current_handle(void) 842{ 843 return current->journal_info; 844} 845 846/* The journaling code user interface: 847 * 848 * Create and destroy handles 849 * Register buffer modifications against the current transaction. 850 */ 851 852extern handle_t *journal_start(journal_t *, int nblocks); 853extern int journal_restart (handle_t *, int nblocks); 854extern int journal_extend (handle_t *, int nblocks); 855extern int journal_get_write_access(handle_t *, struct buffer_head *); 856extern int journal_get_create_access (handle_t *, struct buffer_head *); 857extern int journal_get_undo_access(handle_t *, struct buffer_head *); 858extern int journal_dirty_data (handle_t *, struct buffer_head *); 859extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 860extern void journal_release_buffer (handle_t *, struct buffer_head *); 861extern int journal_forget (handle_t *, struct buffer_head *); 862extern void journal_sync_buffer (struct buffer_head *); 863extern void journal_invalidatepage(journal_t *, 864 struct page *, unsigned int, unsigned int); 865extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 866extern int journal_stop(handle_t *); 867extern int journal_flush (journal_t *); 868extern void journal_lock_updates (journal_t *); 869extern void journal_unlock_updates (journal_t *); 870 871extern journal_t * journal_init_dev(struct block_device *bdev, 872 struct block_device *fs_dev, 873 int start, int len, int bsize); 874extern journal_t * journal_init_inode (struct inode *); 875extern int journal_update_format (journal_t *); 876extern int journal_check_used_features 877 (journal_t *, unsigned long, unsigned long, unsigned long); 878extern int journal_check_available_features 879 (journal_t *, unsigned long, unsigned long, unsigned long); 880extern int journal_set_features 881 (journal_t *, unsigned long, unsigned long, unsigned long); 882extern int journal_create (journal_t *); 883extern int journal_load (journal_t *journal); 884extern int journal_destroy (journal_t *); 885extern int journal_recover (journal_t *journal); 886extern int journal_wipe (journal_t *, int); 887extern int journal_skip_recovery (journal_t *); 888extern void journal_update_sb_log_tail (journal_t *, tid_t, unsigned int, 889 int); 890extern void journal_abort (journal_t *, int); 891extern int journal_errno (journal_t *); 892extern void journal_ack_err (journal_t *); 893extern int journal_clear_err (journal_t *); 894extern int journal_bmap(journal_t *, unsigned int, unsigned int *); 895extern int journal_force_commit(journal_t *); 896 897/* 898 * journal_head management 899 */ 900struct journal_head *journal_add_journal_head(struct buffer_head *bh); 901struct journal_head *journal_grab_journal_head(struct buffer_head *bh); 902void journal_put_journal_head(struct journal_head *jh); 903 904/* 905 * handle management 906 */ 907extern struct kmem_cache *jbd_handle_cache; 908 909static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) 910{ 911 return kmem_cache_zalloc(jbd_handle_cache, gfp_flags); 912} 913 914static inline void jbd_free_handle(handle_t *handle) 915{ 916 kmem_cache_free(jbd_handle_cache, handle); 917} 918 919/* Primary revoke support */ 920#define JOURNAL_REVOKE_DEFAULT_HASH 256 921extern int journal_init_revoke(journal_t *, int); 922extern void journal_destroy_revoke_caches(void); 923extern int journal_init_revoke_caches(void); 924 925extern void journal_destroy_revoke(journal_t *); 926extern int journal_revoke (handle_t *, 927 unsigned int, struct buffer_head *); 928extern int journal_cancel_revoke(handle_t *, struct journal_head *); 929extern void journal_write_revoke_records(journal_t *, 930 transaction_t *, int); 931 932/* Recovery revoke support */ 933extern int journal_set_revoke(journal_t *, unsigned int, tid_t); 934extern int journal_test_revoke(journal_t *, unsigned int, tid_t); 935extern void journal_clear_revoke(journal_t *); 936extern void journal_switch_revoke_table(journal_t *journal); 937extern void journal_clear_buffer_revoked_flags(journal_t *journal); 938 939/* 940 * The log thread user interface: 941 * 942 * Request space in the current transaction, and force transaction commit 943 * transitions on demand. 944 */ 945 946int __log_space_left(journal_t *); /* Called with journal locked */ 947int log_start_commit(journal_t *journal, tid_t tid); 948int __log_start_commit(journal_t *journal, tid_t tid); 949int journal_start_commit(journal_t *journal, tid_t *tid); 950int journal_force_commit_nested(journal_t *journal); 951int log_wait_commit(journal_t *journal, tid_t tid); 952int log_do_checkpoint(journal_t *journal); 953int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 954 955void __log_wait_for_space(journal_t *journal); 956extern void __journal_drop_transaction(journal_t *, transaction_t *); 957extern int cleanup_journal_tail(journal_t *); 958 959/* 960 * is_journal_abort 961 * 962 * Simple test wrapper function to test the JFS_ABORT state flag. This 963 * bit, when set, indicates that we have had a fatal error somewhere, 964 * either inside the journaling layer or indicated to us by the client 965 * (eg. ext3), and that we and should not commit any further 966 * transactions. 967 */ 968 969static inline int is_journal_aborted(journal_t *journal) 970{ 971 return journal->j_flags & JFS_ABORT; 972} 973 974static inline int is_handle_aborted(handle_t *handle) 975{ 976 if (handle->h_aborted) 977 return 1; 978 return is_journal_aborted(handle->h_transaction->t_journal); 979} 980 981static inline void journal_abort_handle(handle_t *handle) 982{ 983 handle->h_aborted = 1; 984} 985 986#endif /* __KERNEL__ */ 987 988/* Comparison functions for transaction IDs: perform comparisons using 989 * modulo arithmetic so that they work over sequence number wraps. */ 990 991static inline int tid_gt(tid_t x, tid_t y) 992{ 993 int difference = (x - y); 994 return (difference > 0); 995} 996 997static inline int tid_geq(tid_t x, tid_t y) 998{ 999 int difference = (x - y); 1000 return (difference >= 0); 1001} 1002 1003extern int journal_blocks_per_page(struct inode *inode); 1004 1005/* 1006 * Return the minimum number of blocks which must be free in the journal 1007 * before a new transaction may be started. Must be called under j_state_lock. 1008 */ 1009static inline int jbd_space_needed(journal_t *journal) 1010{ 1011 int nblocks = journal->j_max_transaction_buffers; 1012 if (journal->j_committing_transaction) 1013 nblocks += journal->j_committing_transaction-> 1014 t_outstanding_credits; 1015 return nblocks; 1016} 1017 1018/* 1019 * Definitions which augment the buffer_head layer 1020 */ 1021 1022/* journaling buffer types */ 1023#define BJ_None 0 /* Not journaled */ 1024#define BJ_SyncData 1 /* Normal data: flush before commit */ 1025#define BJ_Metadata 2 /* Normal journaled metadata */ 1026#define BJ_Forget 3 /* Buffer superseded by this transaction */ 1027#define BJ_IO 4 /* Buffer is for temporary IO use */ 1028#define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1029#define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1030#define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1031#define BJ_Locked 8 /* Locked for I/O during commit */ 1032#define BJ_Types 9 1033 1034extern int jbd_blocks_per_page(struct inode *inode); 1035 1036#ifdef __KERNEL__ 1037 1038#define buffer_trace_init(bh) do {} while (0) 1039#define print_buffer_fields(bh) do {} while (0) 1040#define print_buffer_trace(bh) do {} while (0) 1041#define BUFFER_TRACE(bh, info) do {} while (0) 1042#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1043#define JBUFFER_TRACE(jh, info) do {} while (0) 1044 1045#endif /* __KERNEL__ */ 1046 1047#endif /* _LINUX_JBD_H */ 1048