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 60#define jbd_debug(n, f, a...) \ 61 do { \ 62 if ((n) <= journal_enable_debug) { \ 63 printk (KERN_DEBUG "(%s, %d): %s: ", \ 64 __FILE__, __LINE__, __func__); \ 65 printk (f, ## a); \ 66 } \ 67 } while (0) 68#else 69#define jbd_debug(f, a...) /**/ 70#endif 71 72static inline void *jbd_alloc(size_t size, gfp_t flags) 73{ 74 return (void *)__get_free_pages(flags, get_order(size)); 75} 76 77static inline void jbd_free(void *ptr, size_t size) 78{ 79 free_pages((unsigned long)ptr, get_order(size)); 80}; 81 82#define JFS_MIN_JOURNAL_BLOCKS 1024 83 84 85/** 86 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 87 * 88 * All filesystem modifications made by the process go 89 * through this handle. Recursive operations (such as quota operations) 90 * are gathered into a single update. 91 * 92 * The buffer credits field is used to account for journaled buffers 93 * being modified by the running process. To ensure that there is 94 * enough log space for all outstanding operations, we need to limit the 95 * number of outstanding buffers possible at any time. When the 96 * operation completes, any buffer credits not used are credited back to 97 * the transaction, so that at all times we know how many buffers the 98 * outstanding updates on a transaction might possibly touch. 99 * 100 * This is an opaque datatype. 101 **/ 102typedef struct handle_s handle_t; /* Atomic operation type */ 103 104 105/** 106 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 107 * 108 * journal_t is linked to from the fs superblock structure. 109 * 110 * We use the journal_t to keep track of all outstanding transaction 111 * activity on the filesystem, and to manage the state of the log 112 * writing process. 113 * 114 * This is an opaque datatype. 115 **/ 116typedef struct journal_s journal_t; /* Journal control structure */ 117#endif 118 119/* 120 * Internal structures used by the logging mechanism: 121 */ 122 123#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 124 125/* 126 * On-disk structures 127 */ 128 129/* 130 * Descriptor block types: 131 */ 132 133#define JFS_DESCRIPTOR_BLOCK 1 134#define JFS_COMMIT_BLOCK 2 135#define JFS_SUPERBLOCK_V1 3 136#define JFS_SUPERBLOCK_V2 4 137#define JFS_REVOKE_BLOCK 5 138 139/* 140 * Standard header for all descriptor blocks: 141 */ 142typedef struct journal_header_s 143{ 144 __be32 h_magic; 145 __be32 h_blocktype; 146 __be32 h_sequence; 147} journal_header_t; 148 149 150/* 151 * The block tag: used to describe a single buffer in the journal 152 */ 153typedef struct journal_block_tag_s 154{ 155 __be32 t_blocknr; /* The on-disk block number */ 156 __be32 t_flags; /* See below */ 157} journal_block_tag_t; 158 159/* 160 * The revoke descriptor: used on disk to describe a series of blocks to 161 * be revoked from the log 162 */ 163typedef struct journal_revoke_header_s 164{ 165 journal_header_t r_header; 166 __be32 r_count; /* Count of bytes used in the block */ 167} journal_revoke_header_t; 168 169 170/* Definitions for the journal tag flags word: */ 171#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 172#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 173#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 174#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 175 176 177/* 178 * The journal superblock. All fields are in big-endian byte order. 179 */ 180typedef struct journal_superblock_s 181{ 182/* 0x0000 */ 183 journal_header_t s_header; 184 185/* 0x000C */ 186 /* Static information describing the journal */ 187 __be32 s_blocksize; /* journal device blocksize */ 188 __be32 s_maxlen; /* total blocks in journal file */ 189 __be32 s_first; /* first block of log information */ 190 191/* 0x0018 */ 192 /* Dynamic information describing the current state of the log */ 193 __be32 s_sequence; /* first commit ID expected in log */ 194 __be32 s_start; /* blocknr of start of log */ 195 196/* 0x0020 */ 197 /* Error value, as set by journal_abort(). */ 198 __be32 s_errno; 199 200/* 0x0024 */ 201 /* Remaining fields are only valid in a version-2 superblock */ 202 __be32 s_feature_compat; /* compatible feature set */ 203 __be32 s_feature_incompat; /* incompatible feature set */ 204 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 205/* 0x0030 */ 206 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 207 208/* 0x0040 */ 209 __be32 s_nr_users; /* Nr of filesystems sharing log */ 210 211 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 212 213/* 0x0048 */ 214 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 215 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 216 217/* 0x0050 */ 218 __u32 s_padding[44]; 219 220/* 0x0100 */ 221 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 222/* 0x0400 */ 223} journal_superblock_t; 224 225#define JFS_HAS_COMPAT_FEATURE(j,mask) \ 226 ((j)->j_format_version >= 2 && \ 227 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 228#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 229 ((j)->j_format_version >= 2 && \ 230 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 231#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 232 ((j)->j_format_version >= 2 && \ 233 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 234 235#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 236 237/* Features known to this kernel version: */ 238#define JFS_KNOWN_COMPAT_FEATURES 0 239#define JFS_KNOWN_ROCOMPAT_FEATURES 0 240#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE 241 242#ifdef __KERNEL__ 243 244#include <linux/fs.h> 245#include <linux/sched.h> 246 247enum jbd_state_bits { 248 BH_JBD /* Has an attached ext3 journal_head */ 249 = BH_PrivateStart, 250 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 251 BH_Freed, /* Has been freed (truncated) */ 252 BH_Revoked, /* Has been revoked from the log */ 253 BH_RevokeValid, /* Revoked flag is valid */ 254 BH_JBDDirty, /* Is dirty but journaled */ 255 BH_State, /* Pins most journal_head state */ 256 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 257 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 258 BH_JBDPrivateStart, /* First bit available for private use by FS */ 259}; 260 261BUFFER_FNS(JBD, jbd) 262BUFFER_FNS(JWrite, jwrite) 263BUFFER_FNS(JBDDirty, jbddirty) 264TAS_BUFFER_FNS(JBDDirty, jbddirty) 265BUFFER_FNS(Revoked, revoked) 266TAS_BUFFER_FNS(Revoked, revoked) 267BUFFER_FNS(RevokeValid, revokevalid) 268TAS_BUFFER_FNS(RevokeValid, revokevalid) 269BUFFER_FNS(Freed, freed) 270 271#include <linux/jbd_common.h> 272 273#define J_ASSERT(assert) BUG_ON(!(assert)) 274 275#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 276#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 277 278#if defined(JBD_PARANOID_IOFAIL) 279#define J_EXPECT(expr, why...) J_ASSERT(expr) 280#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 281#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 282#else 283#define __journal_expect(expr, why...) \ 284 ({ \ 285 int val = (expr); \ 286 if (!val) { \ 287 printk(KERN_ERR \ 288 "EXT3-fs unexpected failure: %s;\n",# expr); \ 289 printk(KERN_ERR why "\n"); \ 290 } \ 291 val; \ 292 }) 293#define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 294#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 295#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 296#endif 297 298struct jbd_revoke_table_s; 299 300/** 301 * struct handle_s - this is the concrete type associated with handle_t. 302 * @h_transaction: Which compound transaction is this update a part of? 303 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 304 * @h_ref: Reference count on this handle 305 * @h_err: Field for caller's use to track errors through large fs operations 306 * @h_sync: flag for sync-on-close 307 * @h_jdata: flag to force data journaling 308 * @h_aborted: flag indicating fatal error on handle 309 * @h_lockdep_map: lockdep info for debugging lock problems 310 */ 311struct handle_s 312{ 313 /* Which compound transaction is this update a part of? */ 314 transaction_t *h_transaction; 315 316 /* Number of remaining buffers we are allowed to dirty: */ 317 int h_buffer_credits; 318 319 /* Reference count on this handle */ 320 int h_ref; 321 322 /* Field for caller's use to track errors through large fs */ 323 /* operations */ 324 int h_err; 325 326 /* Flags [no locking] */ 327 unsigned int h_sync: 1; /* sync-on-close */ 328 unsigned int h_jdata: 1; /* force data journaling */ 329 unsigned int h_aborted: 1; /* fatal error on handle */ 330 331#ifdef CONFIG_DEBUG_LOCK_ALLOC 332 struct lockdep_map h_lockdep_map; 333#endif 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/* 354 * Lock ranking: 355 * 356 * j_list_lock 357 * ->jbd_lock_bh_journal_head() (This is "innermost") 358 * 359 * j_state_lock 360 * ->jbd_lock_bh_state() 361 * 362 * jbd_lock_bh_state() 363 * ->j_list_lock 364 * 365 * j_state_lock 366 * ->t_handle_lock 367 * 368 * j_state_lock 369 * ->j_list_lock (journal_unmap_buffer) 370 * 371 */ 372 373struct transaction_s 374{ 375 /* Pointer to the journal for this transaction. [no locking] */ 376 journal_t *t_journal; 377 378 /* Sequence number for this transaction [no locking] */ 379 tid_t t_tid; 380 381 /* 382 * Transaction's current state 383 * [no locking - only kjournald alters this] 384 * [j_list_lock] guards transition of a transaction into T_FINISHED 385 * state and subsequent call of __journal_drop_transaction() 386 * FIXME: needs barriers 387 * KLUDGE: [use j_state_lock] 388 */ 389 enum { 390 T_RUNNING, 391 T_LOCKED, 392 T_FLUSH, 393 T_COMMIT, 394 T_COMMIT_RECORD, 395 T_FINISHED 396 } t_state; 397 398 /* 399 * Where in the log does this transaction's commit start? [no locking] 400 */ 401 unsigned int t_log_start; 402 403 /* Number of buffers on the t_buffers list [j_list_lock] */ 404 int t_nr_buffers; 405 406 /* 407 * Doubly-linked circular list of all buffers reserved but not yet 408 * modified by this transaction [j_list_lock] 409 */ 410 struct journal_head *t_reserved_list; 411 412 /* 413 * Doubly-linked circular list of all buffers under writeout during 414 * commit [j_list_lock] 415 */ 416 struct journal_head *t_locked_list; 417 418 /* 419 * Doubly-linked circular list of all metadata buffers owned by this 420 * transaction [j_list_lock] 421 */ 422 struct journal_head *t_buffers; 423 424 /* 425 * Doubly-linked circular list of all data buffers still to be 426 * flushed before this transaction can be committed [j_list_lock] 427 */ 428 struct journal_head *t_sync_datalist; 429 430 /* 431 * Doubly-linked circular list of all forget buffers (superseded 432 * buffers which we can un-checkpoint once this transaction commits) 433 * [j_list_lock] 434 */ 435 struct journal_head *t_forget; 436 437 /* 438 * Doubly-linked circular list of all buffers still to be flushed before 439 * this transaction can be checkpointed. [j_list_lock] 440 */ 441 struct journal_head *t_checkpoint_list; 442 443 /* 444 * Doubly-linked circular list of all buffers submitted for IO while 445 * checkpointing. [j_list_lock] 446 */ 447 struct journal_head *t_checkpoint_io_list; 448 449 /* 450 * Doubly-linked circular list of temporary buffers currently undergoing 451 * IO in the log [j_list_lock] 452 */ 453 struct journal_head *t_iobuf_list; 454 455 /* 456 * Doubly-linked circular list of metadata buffers being shadowed by log 457 * IO. The IO buffers on the iobuf list and the shadow buffers on this 458 * list match each other one for one at all times. [j_list_lock] 459 */ 460 struct journal_head *t_shadow_list; 461 462 /* 463 * Doubly-linked circular list of control buffers being written to the 464 * log. [j_list_lock] 465 */ 466 struct journal_head *t_log_list; 467 468 /* 469 * Protects info related to handles 470 */ 471 spinlock_t t_handle_lock; 472 473 /* 474 * Number of outstanding updates running on this transaction 475 * [t_handle_lock] 476 */ 477 int t_updates; 478 479 /* 480 * Number of buffers reserved for use by all handles in this transaction 481 * handle but not yet modified. [t_handle_lock] 482 */ 483 int t_outstanding_credits; 484 485 /* 486 * Forward and backward links for the circular list of all transactions 487 * awaiting checkpoint. [j_list_lock] 488 */ 489 transaction_t *t_cpnext, *t_cpprev; 490 491 /* 492 * When will the transaction expire (become due for commit), in jiffies? 493 * [no locking] 494 */ 495 unsigned long t_expires; 496 497 /* 498 * When this transaction started, in nanoseconds [no locking] 499 */ 500 ktime_t t_start_time; 501 502 /* 503 * How many handles used this transaction? [t_handle_lock] 504 */ 505 int t_handle_count; 506}; 507 508/** 509 * struct journal_s - this is the concrete type associated with journal_t. 510 * @j_flags: General journaling state flags 511 * @j_errno: Is there an outstanding uncleared error on the journal (from a 512 * prior abort)? 513 * @j_sb_buffer: First part of superblock buffer 514 * @j_superblock: Second part of superblock buffer 515 * @j_format_version: Version of the superblock format 516 * @j_state_lock: Protect the various scalars in the journal 517 * @j_barrier_count: Number of processes waiting to create a barrier lock 518 * @j_running_transaction: The current running transaction.. 519 * @j_committing_transaction: the transaction we are pushing to disk 520 * @j_checkpoint_transactions: a linked circular list of all transactions 521 * waiting for checkpointing 522 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 523 * to start committing, or for a barrier lock to be released 524 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 525 * @j_wait_done_commit: Wait queue for waiting for commit to complete 526 * @j_wait_checkpoint: Wait queue to trigger checkpointing 527 * @j_wait_commit: Wait queue to trigger commit 528 * @j_wait_updates: Wait queue to wait for updates to complete 529 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 530 * @j_head: Journal head - identifies the first unused block in the journal 531 * @j_tail: Journal tail - identifies the oldest still-used block in the 532 * journal. 533 * @j_free: Journal free - how many free blocks are there in the journal? 534 * @j_first: The block number of the first usable block 535 * @j_last: The block number one beyond the last usable block 536 * @j_dev: Device where we store the journal 537 * @j_blocksize: blocksize for the location where we store the journal. 538 * @j_blk_offset: starting block offset for into the device where we store the 539 * journal 540 * @j_fs_dev: Device which holds the client fs. For internal journal this will 541 * be equal to j_dev 542 * @j_maxlen: Total maximum capacity of the journal region on disk. 543 * @j_list_lock: Protects the buffer lists and internal buffer state. 544 * @j_inode: Optional inode where we store the journal. If present, all journal 545 * block numbers are mapped into this inode via bmap(). 546 * @j_tail_sequence: Sequence number of the oldest transaction in the log 547 * @j_transaction_sequence: Sequence number of the next transaction to grant 548 * @j_commit_sequence: Sequence number of the most recently committed 549 * transaction 550 * @j_commit_request: Sequence number of the most recent transaction wanting 551 * commit 552 * @j_commit_waited: Sequence number of the most recent transaction someone 553 * is waiting for to commit. 554 * @j_uuid: Uuid of client object. 555 * @j_task: Pointer to the current commit thread for this journal 556 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 557 * single compound commit transaction 558 * @j_commit_interval: What is the maximum transaction lifetime before we begin 559 * a commit? 560 * @j_commit_timer: The timer used to wakeup the commit thread 561 * @j_revoke_lock: Protect the revoke table 562 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 563 * current transaction. 564 * @j_revoke_table: alternate revoke tables for j_revoke 565 * @j_wbuf: array of buffer_heads for journal_commit_transaction 566 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 567 * number that will fit in j_blocksize 568 * @j_last_sync_writer: most recent pid which did a synchronous write 569 * @j_average_commit_time: the average amount of time in nanoseconds it 570 * takes to commit a transaction to the disk. 571 * @j_private: An opaque pointer to fs-private information. 572 */ 573 574struct journal_s 575{ 576 /* General journaling state flags [j_state_lock] */ 577 unsigned long j_flags; 578 579 /* 580 * Is there an outstanding uncleared error on the journal (from a prior 581 * abort)? [j_state_lock] 582 */ 583 int j_errno; 584 585 /* The superblock buffer */ 586 struct buffer_head *j_sb_buffer; 587 journal_superblock_t *j_superblock; 588 589 /* Version of the superblock format */ 590 int j_format_version; 591 592 /* 593 * Protect the various scalars in the journal 594 */ 595 spinlock_t j_state_lock; 596 597 /* 598 * Number of processes waiting to create a barrier lock [j_state_lock] 599 */ 600 int j_barrier_count; 601 602 /* 603 * Transactions: The current running transaction... 604 * [j_state_lock] [caller holding open handle] 605 */ 606 transaction_t *j_running_transaction; 607 608 /* 609 * the transaction we are pushing to disk 610 * [j_state_lock] [caller holding open handle] 611 */ 612 transaction_t *j_committing_transaction; 613 614 /* 615 * ... and a linked circular list of all transactions waiting for 616 * checkpointing. [j_list_lock] 617 */ 618 transaction_t *j_checkpoint_transactions; 619 620 /* 621 * Wait queue for waiting for a locked transaction to start committing, 622 * or for a barrier lock to be released 623 */ 624 wait_queue_head_t j_wait_transaction_locked; 625 626 /* Wait queue for waiting for checkpointing to complete */ 627 wait_queue_head_t j_wait_logspace; 628 629 /* Wait queue for waiting for commit to complete */ 630 wait_queue_head_t j_wait_done_commit; 631 632 /* Wait queue to trigger checkpointing */ 633 wait_queue_head_t j_wait_checkpoint; 634 635 /* Wait queue to trigger commit */ 636 wait_queue_head_t j_wait_commit; 637 638 /* Wait queue to wait for updates to complete */ 639 wait_queue_head_t j_wait_updates; 640 641 /* Semaphore for locking against concurrent checkpoints */ 642 struct mutex j_checkpoint_mutex; 643 644 /* 645 * Journal head: identifies the first unused block in the journal. 646 * [j_state_lock] 647 */ 648 unsigned int j_head; 649 650 /* 651 * Journal tail: identifies the oldest still-used block in the journal. 652 * [j_state_lock] 653 */ 654 unsigned int j_tail; 655 656 /* 657 * Journal free: how many free blocks are there in the journal? 658 * [j_state_lock] 659 */ 660 unsigned int j_free; 661 662 /* 663 * Journal start and end: the block numbers of the first usable block 664 * and one beyond the last usable block in the journal. [j_state_lock] 665 */ 666 unsigned int j_first; 667 unsigned int j_last; 668 669 /* 670 * Device, blocksize and starting block offset for the location where we 671 * store the journal. 672 */ 673 struct block_device *j_dev; 674 int j_blocksize; 675 unsigned int j_blk_offset; 676 677 /* 678 * Device which holds the client fs. For internal journal this will be 679 * equal to j_dev. 680 */ 681 struct block_device *j_fs_dev; 682 683 /* Total maximum capacity of the journal region on disk. */ 684 unsigned int j_maxlen; 685 686 /* 687 * Protects the buffer lists and internal buffer state. 688 */ 689 spinlock_t j_list_lock; 690 691 /* Optional inode where we store the journal. If present, all */ 692 /* journal block numbers are mapped into this inode via */ 693 /* bmap(). */ 694 struct inode *j_inode; 695 696 /* 697 * Sequence number of the oldest transaction in the log [j_state_lock] 698 */ 699 tid_t j_tail_sequence; 700 701 /* 702 * Sequence number of the next transaction to grant [j_state_lock] 703 */ 704 tid_t j_transaction_sequence; 705 706 /* 707 * Sequence number of the most recently committed transaction 708 * [j_state_lock]. 709 */ 710 tid_t j_commit_sequence; 711 712 /* 713 * Sequence number of the most recent transaction wanting commit 714 * [j_state_lock] 715 */ 716 tid_t j_commit_request; 717 718 /* 719 * Sequence number of the most recent transaction someone is waiting 720 * for to commit. 721 * [j_state_lock] 722 */ 723 tid_t j_commit_waited; 724 725 /* 726 * Journal uuid: identifies the object (filesystem, LVM volume etc) 727 * backed by this journal. This will eventually be replaced by an array 728 * of uuids, allowing us to index multiple devices within a single 729 * journal and to perform atomic updates across them. 730 */ 731 __u8 j_uuid[16]; 732 733 /* Pointer to the current commit thread for this journal */ 734 struct task_struct *j_task; 735 736 /* 737 * Maximum number of metadata buffers to allow in a single compound 738 * commit transaction 739 */ 740 int j_max_transaction_buffers; 741 742 /* 743 * What is the maximum transaction lifetime before we begin a commit? 744 */ 745 unsigned long j_commit_interval; 746 747 /* The timer used to wakeup the commit thread: */ 748 struct timer_list j_commit_timer; 749 750 /* 751 * The revoke table: maintains the list of revoked blocks in the 752 * current transaction. [j_revoke_lock] 753 */ 754 spinlock_t j_revoke_lock; 755 struct jbd_revoke_table_s *j_revoke; 756 struct jbd_revoke_table_s *j_revoke_table[2]; 757 758 /* 759 * array of bhs for journal_commit_transaction 760 */ 761 struct buffer_head **j_wbuf; 762 int j_wbufsize; 763 764 /* 765 * this is the pid of the last person to run a synchronous operation 766 * through the journal. 767 */ 768 pid_t j_last_sync_writer; 769 770 /* 771 * the average amount of time in nanoseconds it takes to commit a 772 * transaction to the disk. [j_state_lock] 773 */ 774 u64 j_average_commit_time; 775 776 /* 777 * An opaque pointer to fs-private information. ext3 puts its 778 * superblock pointer here 779 */ 780 void *j_private; 781}; 782 783/* 784 * Journal flag definitions 785 */ 786#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 787#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 788#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 789#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 790#define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 791#define JFS_BARRIER 0x020 /* Use IDE barriers */ 792#define JFS_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 793 * data write error in ordered 794 * mode */ 795 796/* 797 * Function declarations for the journaling transaction and buffer 798 * management 799 */ 800 801/* Filing buffers */ 802extern void journal_unfile_buffer(journal_t *, struct journal_head *); 803extern void __journal_unfile_buffer(struct journal_head *); 804extern void __journal_refile_buffer(struct journal_head *); 805extern void journal_refile_buffer(journal_t *, struct journal_head *); 806extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 807extern void __journal_free_buffer(struct journal_head *bh); 808extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 809extern void __journal_clean_data_list(transaction_t *transaction); 810 811/* Log buffer allocation */ 812extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 813int journal_next_log_block(journal_t *, unsigned int *); 814 815/* Commit management */ 816extern void journal_commit_transaction(journal_t *); 817 818/* Checkpoint list management */ 819int __journal_clean_checkpoint_list(journal_t *journal); 820int __journal_remove_checkpoint(struct journal_head *); 821void __journal_insert_checkpoint(struct journal_head *, transaction_t *); 822 823/* Buffer IO */ 824extern int 825journal_write_metadata_buffer(transaction_t *transaction, 826 struct journal_head *jh_in, 827 struct journal_head **jh_out, 828 unsigned int blocknr); 829 830/* Transaction locking */ 831extern void __wait_on_journal (journal_t *); 832 833/* 834 * Journal locking. 835 * 836 * We need to lock the journal during transaction state changes so that nobody 837 * ever tries to take a handle on the running transaction while we are in the 838 * middle of moving it to the commit phase. j_state_lock does this. 839 * 840 * Note that the locking is completely interrupt unsafe. We never touch 841 * journal structures from interrupts. 842 */ 843 844static inline handle_t *journal_current_handle(void) 845{ 846 return current->journal_info; 847} 848 849/* The journaling code user interface: 850 * 851 * Create and destroy handles 852 * Register buffer modifications against the current transaction. 853 */ 854 855extern handle_t *journal_start(journal_t *, int nblocks); 856extern int journal_restart (handle_t *, int nblocks); 857extern int journal_extend (handle_t *, int nblocks); 858extern int journal_get_write_access(handle_t *, struct buffer_head *); 859extern int journal_get_create_access (handle_t *, struct buffer_head *); 860extern int journal_get_undo_access(handle_t *, struct buffer_head *); 861extern int journal_dirty_data (handle_t *, struct buffer_head *); 862extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 863extern void journal_release_buffer (handle_t *, struct buffer_head *); 864extern int journal_forget (handle_t *, struct buffer_head *); 865extern void journal_sync_buffer (struct buffer_head *); 866extern void journal_invalidatepage(journal_t *, 867 struct page *, unsigned int, unsigned int); 868extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 869extern int journal_stop(handle_t *); 870extern int journal_flush (journal_t *); 871extern void journal_lock_updates (journal_t *); 872extern void journal_unlock_updates (journal_t *); 873 874extern journal_t * journal_init_dev(struct block_device *bdev, 875 struct block_device *fs_dev, 876 int start, int len, int bsize); 877extern journal_t * journal_init_inode (struct inode *); 878extern int journal_update_format (journal_t *); 879extern int journal_check_used_features 880 (journal_t *, unsigned long, unsigned long, unsigned long); 881extern int journal_check_available_features 882 (journal_t *, unsigned long, unsigned long, unsigned long); 883extern int journal_set_features 884 (journal_t *, unsigned long, unsigned long, unsigned long); 885extern int journal_create (journal_t *); 886extern int journal_load (journal_t *journal); 887extern int journal_destroy (journal_t *); 888extern int journal_recover (journal_t *journal); 889extern int journal_wipe (journal_t *, int); 890extern int journal_skip_recovery (journal_t *); 891extern void journal_update_sb_log_tail (journal_t *, tid_t, unsigned int, 892 int); 893extern void journal_abort (journal_t *, int); 894extern int journal_errno (journal_t *); 895extern void journal_ack_err (journal_t *); 896extern int journal_clear_err (journal_t *); 897extern int journal_bmap(journal_t *, unsigned int, unsigned int *); 898extern int journal_force_commit(journal_t *); 899 900/* 901 * journal_head management 902 */ 903struct journal_head *journal_add_journal_head(struct buffer_head *bh); 904struct journal_head *journal_grab_journal_head(struct buffer_head *bh); 905void journal_put_journal_head(struct journal_head *jh); 906 907/* 908 * handle management 909 */ 910extern struct kmem_cache *jbd_handle_cache; 911 912static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) 913{ 914 return kmem_cache_zalloc(jbd_handle_cache, gfp_flags); 915} 916 917static inline void jbd_free_handle(handle_t *handle) 918{ 919 kmem_cache_free(jbd_handle_cache, handle); 920} 921 922/* Primary revoke support */ 923#define JOURNAL_REVOKE_DEFAULT_HASH 256 924extern int journal_init_revoke(journal_t *, int); 925extern void journal_destroy_revoke_caches(void); 926extern int journal_init_revoke_caches(void); 927 928extern void journal_destroy_revoke(journal_t *); 929extern int journal_revoke (handle_t *, 930 unsigned int, struct buffer_head *); 931extern int journal_cancel_revoke(handle_t *, struct journal_head *); 932extern void journal_write_revoke_records(journal_t *, 933 transaction_t *, int); 934 935/* Recovery revoke support */ 936extern int journal_set_revoke(journal_t *, unsigned int, tid_t); 937extern int journal_test_revoke(journal_t *, unsigned int, tid_t); 938extern void journal_clear_revoke(journal_t *); 939extern void journal_switch_revoke_table(journal_t *journal); 940extern void journal_clear_buffer_revoked_flags(journal_t *journal); 941 942/* 943 * The log thread user interface: 944 * 945 * Request space in the current transaction, and force transaction commit 946 * transitions on demand. 947 */ 948 949int __log_space_left(journal_t *); /* Called with journal locked */ 950int log_start_commit(journal_t *journal, tid_t tid); 951int __log_start_commit(journal_t *journal, tid_t tid); 952int journal_start_commit(journal_t *journal, tid_t *tid); 953int journal_force_commit_nested(journal_t *journal); 954int log_wait_commit(journal_t *journal, tid_t tid); 955int log_do_checkpoint(journal_t *journal); 956int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 957 958void __log_wait_for_space(journal_t *journal); 959extern void __journal_drop_transaction(journal_t *, transaction_t *); 960extern int cleanup_journal_tail(journal_t *); 961 962/* Debugging code only: */ 963 964#define jbd_ENOSYS() \ 965do { \ 966 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \ 967 current->state = TASK_UNINTERRUPTIBLE; \ 968 schedule(); \ 969} while (1) 970 971/* 972 * is_journal_abort 973 * 974 * Simple test wrapper function to test the JFS_ABORT state flag. This 975 * bit, when set, indicates that we have had a fatal error somewhere, 976 * either inside the journaling layer or indicated to us by the client 977 * (eg. ext3), and that we and should not commit any further 978 * transactions. 979 */ 980 981static inline int is_journal_aborted(journal_t *journal) 982{ 983 return journal->j_flags & JFS_ABORT; 984} 985 986static inline int is_handle_aborted(handle_t *handle) 987{ 988 if (handle->h_aborted) 989 return 1; 990 return is_journal_aborted(handle->h_transaction->t_journal); 991} 992 993static inline void journal_abort_handle(handle_t *handle) 994{ 995 handle->h_aborted = 1; 996} 997 998#endif /* __KERNEL__ */ 999 1000/* Comparison functions for transaction IDs: perform comparisons using
1001 * modulo arithmetic so that they work over sequence number wraps. */ 1002 1003static inline int tid_gt(tid_t x, tid_t y) 1004{ 1005 int difference = (x - y); 1006 return (difference > 0); 1007} 1008 1009static inline int tid_geq(tid_t x, tid_t y) 1010{ 1011 int difference = (x - y); 1012 return (difference >= 0); 1013} 1014 1015extern int journal_blocks_per_page(struct inode *inode); 1016 1017/* 1018 * Return the minimum number of blocks which must be free in the journal 1019 * before a new transaction may be started. Must be called under j_state_lock. 1020 */ 1021static inline int jbd_space_needed(journal_t *journal) 1022{ 1023 int nblocks = journal->j_max_transaction_buffers; 1024 if (journal->j_committing_transaction) 1025 nblocks += journal->j_committing_transaction-> 1026 t_outstanding_credits; 1027 return nblocks; 1028} 1029 1030/* 1031 * Definitions which augment the buffer_head layer 1032 */ 1033 1034/* journaling buffer types */ 1035#define BJ_None 0 /* Not journaled */ 1036#define BJ_SyncData 1 /* Normal data: flush before commit */ 1037#define BJ_Metadata 2 /* Normal journaled metadata */ 1038#define BJ_Forget 3 /* Buffer superseded by this transaction */ 1039#define BJ_IO 4 /* Buffer is for temporary IO use */ 1040#define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1041#define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1042#define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1043#define BJ_Locked 8 /* Locked for I/O during commit */ 1044#define BJ_Types 9 1045 1046extern int jbd_blocks_per_page(struct inode *inode); 1047 1048#ifdef __KERNEL__ 1049 1050#define buffer_trace_init(bh) do {} while (0) 1051#define print_buffer_fields(bh) do {} while (0) 1052#define print_buffer_trace(bh) do {} while (0) 1053#define BUFFER_TRACE(bh, info) do {} while (0) 1054#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1055#define JBUFFER_TRACE(jh, info) do {} while (0) 1056 1057#endif /* __KERNEL__ */ 1058 1059#endif /* _LINUX_JBD_H */ 1060