1/* 2 * linux/include/linux/jbd2.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 JBD2_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/bit_spinlock.h> 31#include <linux/mutex.h> 32#include <linux/timer.h> 33 34#include <asm/semaphore.h> 35#endif 36 37#define journal_oom_retry 1 38 39/* 40 * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds 41 * certain classes of error which can occur due to failed IOs. Under 42 * normal use we want ext3 to continue after such errors, because 43 * hardware _can_ fail, but for debugging purposes when running tests on 44 * known-good hardware we may want to trap these errors. 45 */ 46#undef JBD_PARANOID_IOFAIL 47 48/* 49 * The default maximum commit age, in seconds. 50 */ 51#define JBD_DEFAULT_MAX_COMMIT_AGE 5 52 53#ifdef CONFIG_JBD_DEBUG 54/* 55 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal 56 * consistency checks. By default we don't do this unless 57 * CONFIG_JBD_DEBUG is on. 58 */ 59#define JBD_EXPENSIVE_CHECKING 60extern int jbd2_journal_enable_debug; 61 62#define jbd_debug(n, f, a...) \ 63 do { \ 64 if ((n) <= jbd2_journal_enable_debug) { \ 65 printk (KERN_DEBUG "(%s, %d): %s: ", \ 66 __FILE__, __LINE__, __FUNCTION__); \ 67 printk (f, ## a); \ 68 } \ 69 } while (0) 70#else 71#define jbd_debug(f, a...) /**/ 72#endif 73 74extern void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry); 75extern void * jbd2_slab_alloc(size_t size, gfp_t flags); 76extern void jbd2_slab_free(void *ptr, size_t size); 77 78#define jbd_kmalloc(size, flags) \ 79 __jbd2_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry) 80#define jbd_rep_kmalloc(size, flags) \ 81 __jbd2_kmalloc(__FUNCTION__, (size), (flags), 1) 82 83#define JBD2_MIN_JOURNAL_BLOCKS 1024 84 85#ifdef __KERNEL__ 86 87/** 88 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 89 * 90 * All filesystem modifications made by the process go 91 * through this handle. Recursive operations (such as quota operations) 92 * are gathered into a single update. 93 * 94 * The buffer credits field is used to account for journaled buffers 95 * being modified by the running process. To ensure that there is 96 * enough log space for all outstanding operations, we need to limit the 97 * number of outstanding buffers possible at any time. When the 98 * operation completes, any buffer credits not used are credited back to 99 * the transaction, so that at all times we know how many buffers the 100 * outstanding updates on a transaction might possibly touch. 101 * 102 * This is an opaque datatype. 103 **/ 104typedef struct handle_s handle_t; /* Atomic operation type */ 105 106 107/** 108 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 109 * 110 * journal_t is linked to from the fs superblock structure. 111 * 112 * We use the journal_t to keep track of all outstanding transaction 113 * activity on the filesystem, and to manage the state of the log 114 * writing process. 115 * 116 * This is an opaque datatype. 117 **/ 118typedef struct journal_s journal_t; /* Journal control structure */ 119#endif 120 121/* 122 * Internal structures used by the logging mechanism: 123 */ 124 125#define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 126 127/* 128 * On-disk structures 129 */ 130 131/* 132 * Descriptor block types: 133 */ 134 135#define JBD2_DESCRIPTOR_BLOCK 1 136#define JBD2_COMMIT_BLOCK 2 137#define JBD2_SUPERBLOCK_V1 3 138#define JBD2_SUPERBLOCK_V2 4 139#define JBD2_REVOKE_BLOCK 5 140 141/* 142 * Standard header for all descriptor blocks: 143 */ 144typedef struct journal_header_s 145{ 146 __be32 h_magic; 147 __be32 h_blocktype; 148 __be32 h_sequence; 149} journal_header_t; 150 151 152/* 153 * The block tag: used to describe a single buffer in the journal. 154 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 155 * raw struct shouldn't be used for pointer math or sizeof() - use 156 * journal_tag_bytes(journal) instead to compute this. 157 */ 158typedef struct journal_block_tag_s 159{ 160 __be32 t_blocknr; /* The on-disk block number */ 161 __be32 t_flags; /* See below */ 162 __be32 t_blocknr_high; /* most-significant high 32bits. */ 163} journal_block_tag_t; 164 165#define JBD_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 166#define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t)) 167 168/* 169 * The revoke descriptor: used on disk to describe a series of blocks to 170 * be revoked from the log 171 */ 172typedef struct jbd2_journal_revoke_header_s 173{ 174 journal_header_t r_header; 175 __be32 r_count; /* Count of bytes used in the block */ 176} jbd2_journal_revoke_header_t; 177 178 179/* Definitions for the journal tag flags word: */ 180#define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 181#define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 182#define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 183#define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 184 185 186/* 187 * The journal superblock. All fields are in big-endian byte order. 188 */ 189typedef struct journal_superblock_s 190{ 191/* 0x0000 */ 192 journal_header_t s_header; 193 194/* 0x000C */ 195 /* Static information describing the journal */ 196 __be32 s_blocksize; /* journal device blocksize */ 197 __be32 s_maxlen; /* total blocks in journal file */ 198 __be32 s_first; /* first block of log information */ 199 200/* 0x0018 */ 201 /* Dynamic information describing the current state of the log */ 202 __be32 s_sequence; /* first commit ID expected in log */ 203 __be32 s_start; /* blocknr of start of log */ 204 205/* 0x0020 */ 206 /* Error value, as set by jbd2_journal_abort(). */ 207 __be32 s_errno; 208 209/* 0x0024 */ 210 /* Remaining fields are only valid in a version-2 superblock */ 211 __be32 s_feature_compat; /* compatible feature set */ 212 __be32 s_feature_incompat; /* incompatible feature set */ 213 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 214/* 0x0030 */ 215 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 216 217/* 0x0040 */ 218 __be32 s_nr_users; /* Nr of filesystems sharing log */ 219 220 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 221 222/* 0x0048 */ 223 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 224 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 225 226/* 0x0050 */ 227 __u32 s_padding[44]; 228 229/* 0x0100 */ 230 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 231/* 0x0400 */ 232} journal_superblock_t; 233 234#define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 235 ((j)->j_format_version >= 2 && \ 236 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 237#define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 238 ((j)->j_format_version >= 2 && \ 239 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 240#define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 241 ((j)->j_format_version >= 2 && \ 242 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 243 244#define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 245#define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 246 247/* Features known to this kernel version: */ 248#define JBD2_KNOWN_COMPAT_FEATURES 0 249#define JBD2_KNOWN_ROCOMPAT_FEATURES 0 250#define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 251 JBD2_FEATURE_INCOMPAT_64BIT) 252 253#ifdef __KERNEL__ 254 255#include <linux/fs.h> 256#include <linux/sched.h> 257 258#define JBD_ASSERTIONS 259#ifdef JBD_ASSERTIONS 260#define J_ASSERT(assert) \ 261do { \ 262 if (!(assert)) { \ 263 printk (KERN_EMERG \ 264 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 265 __FUNCTION__, __FILE__, __LINE__, # assert); \ 266 BUG(); \ 267 } \ 268} while (0) 269 270#if defined(CONFIG_BUFFER_DEBUG) 271void buffer_assertion_failure(struct buffer_head *bh); 272#define J_ASSERT_BH(bh, expr) \ 273 do { \ 274 if (!(expr)) \ 275 buffer_assertion_failure(bh); \ 276 J_ASSERT(expr); \ 277 } while (0) 278#define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 279#else 280#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 281#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 282#endif 283 284#else 285#define J_ASSERT(assert) do { } while (0) 286#endif /* JBD_ASSERTIONS */ 287 288#if defined(JBD_PARANOID_IOFAIL) 289#define J_EXPECT(expr, why...) J_ASSERT(expr) 290#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 291#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 292#else 293#define __journal_expect(expr, why...) \ 294 ({ \ 295 int val = (expr); \ 296 if (!val) { \ 297 printk(KERN_ERR \ 298 "EXT3-fs unexpected failure: %s;\n",# expr); \ 299 printk(KERN_ERR why "\n"); \ 300 } \ 301 val; \ 302 }) 303#define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 304#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 305#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 306#endif 307 308enum jbd_state_bits { 309 BH_JBD /* Has an attached ext3 journal_head */ 310 = BH_PrivateStart, 311 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 312 BH_Freed, /* Has been freed (truncated) */ 313 BH_Revoked, /* Has been revoked from the log */ 314 BH_RevokeValid, /* Revoked flag is valid */ 315 BH_JBDDirty, /* Is dirty but journaled */ 316 BH_State, /* Pins most journal_head state */ 317 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 318 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 319}; 320 321BUFFER_FNS(JBD, jbd) 322BUFFER_FNS(JWrite, jwrite) 323BUFFER_FNS(JBDDirty, jbddirty) 324TAS_BUFFER_FNS(JBDDirty, jbddirty) 325BUFFER_FNS(Revoked, revoked) 326TAS_BUFFER_FNS(Revoked, revoked) 327BUFFER_FNS(RevokeValid, revokevalid) 328TAS_BUFFER_FNS(RevokeValid, revokevalid) 329BUFFER_FNS(Freed, freed) 330 331static inline struct buffer_head *jh2bh(struct journal_head *jh) 332{ 333 return jh->b_bh; 334} 335 336static inline struct journal_head *bh2jh(struct buffer_head *bh) 337{ 338 return bh->b_private; 339} 340 341static inline void jbd_lock_bh_state(struct buffer_head *bh) 342{ 343 bit_spin_lock(BH_State, &bh->b_state); 344} 345 346static inline int jbd_trylock_bh_state(struct buffer_head *bh) 347{ 348 return bit_spin_trylock(BH_State, &bh->b_state); 349} 350 351static inline int jbd_is_locked_bh_state(struct buffer_head *bh) 352{ 353 return bit_spin_is_locked(BH_State, &bh->b_state); 354} 355 356static inline void jbd_unlock_bh_state(struct buffer_head *bh) 357{ 358 bit_spin_unlock(BH_State, &bh->b_state); 359} 360 361static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 362{ 363 bit_spin_lock(BH_JournalHead, &bh->b_state); 364} 365 366static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 367{ 368 bit_spin_unlock(BH_JournalHead, &bh->b_state); 369} 370 371struct jbd2_revoke_table_s; 372 373/** 374 * struct handle_s - The handle_s type is the concrete type associated with 375 * handle_t. 376 * @h_transaction: Which compound transaction is this update a part of? 377 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 378 * @h_ref: Reference count on this handle 379 * @h_err: Field for caller's use to track errors through large fs operations 380 * @h_sync: flag for sync-on-close 381 * @h_jdata: flag to force data journaling 382 * @h_aborted: flag indicating fatal error on handle 383 **/ 384 385/* Docbook can't yet cope with the bit fields, but will leave the documentation 386 * in so it can be fixed later. 387 */ 388 389struct handle_s 390{ 391 /* Which compound transaction is this update a part of? */ 392 transaction_t *h_transaction; 393 394 /* Number of remaining buffers we are allowed to dirty: */ 395 int h_buffer_credits; 396 397 /* Reference count on this handle */ 398 int h_ref; 399 400 /* Field for caller's use to track errors through large fs */ 401 /* operations */ 402 int h_err; 403 404 /* Flags [no locking] */ 405 unsigned int h_sync: 1; /* sync-on-close */ 406 unsigned int h_jdata: 1; /* force data journaling */ 407 unsigned int h_aborted: 1; /* fatal error on handle */ 408}; 409 410 411/* The transaction_t type is the guts of the journaling mechanism. It 412 * tracks a compound transaction through its various states: 413 * 414 * RUNNING: accepting new updates 415 * LOCKED: Updates still running but we don't accept new ones 416 * RUNDOWN: Updates are tidying up but have finished requesting 417 * new buffers to modify (state not used for now) 418 * FLUSH: All updates complete, but we are still writing to disk 419 * COMMIT: All data on disk, writing commit record 420 * FINISHED: We still have to keep the transaction for checkpointing. 421 * 422 * The transaction keeps track of all of the buffers modified by a 423 * running transaction, and all of the buffers committed but not yet 424 * flushed to home for finished transactions. 425 */ 426 427/* 428 * Lock ranking: 429 * 430 * j_list_lock 431 * ->jbd_lock_bh_journal_head() (This is "innermost") 432 * 433 * j_state_lock 434 * ->jbd_lock_bh_state() 435 * 436 * jbd_lock_bh_state() 437 * ->j_list_lock 438 * 439 * j_state_lock 440 * ->t_handle_lock 441 * 442 * j_state_lock 443 * ->j_list_lock (journal_unmap_buffer) 444 * 445 */ 446 447struct transaction_s 448{ 449 /* Pointer to the journal for this transaction. [no locking] */ 450 journal_t *t_journal; 451 452 /* Sequence number for this transaction [no locking] */ 453 tid_t t_tid; 454 455 enum { 456 T_RUNNING, 457 T_LOCKED, 458 T_RUNDOWN, 459 T_FLUSH, 460 T_COMMIT, 461 T_FINISHED 462 } t_state; 463 464 /* 465 * Where in the log does this transaction's commit start? [no locking] 466 */ 467 unsigned long t_log_start; 468 469 /* Number of buffers on the t_buffers list [j_list_lock] */ 470 int t_nr_buffers; 471 472 /* 473 * Doubly-linked circular list of all buffers reserved but not yet 474 * modified by this transaction [j_list_lock] 475 */ 476 struct journal_head *t_reserved_list; 477 478 /* 479 * Doubly-linked circular list of all buffers under writeout during 480 * commit [j_list_lock] 481 */ 482 struct journal_head *t_locked_list; 483 484 /* 485 * Doubly-linked circular list of all metadata buffers owned by this 486 * transaction [j_list_lock] 487 */ 488 struct journal_head *t_buffers; 489 490 /* 491 * Doubly-linked circular list of all data buffers still to be 492 * flushed before this transaction can be committed [j_list_lock] 493 */ 494 struct journal_head *t_sync_datalist; 495 496 /* 497 * Doubly-linked circular list of all forget buffers (superseded 498 * buffers which we can un-checkpoint once this transaction commits) 499 * [j_list_lock] 500 */ 501 struct journal_head *t_forget; 502 503 /* 504 * Doubly-linked circular list of all buffers still to be flushed before 505 * this transaction can be checkpointed. [j_list_lock] 506 */ 507 struct journal_head *t_checkpoint_list; 508 509 /* 510 * Doubly-linked circular list of all buffers submitted for IO while 511 * checkpointing. [j_list_lock] 512 */ 513 struct journal_head *t_checkpoint_io_list; 514 515 /* 516 * Doubly-linked circular list of temporary buffers currently undergoing 517 * IO in the log [j_list_lock] 518 */ 519 struct journal_head *t_iobuf_list; 520 521 /* 522 * Doubly-linked circular list of metadata buffers being shadowed by log 523 * IO. The IO buffers on the iobuf list and the shadow buffers on this 524 * list match each other one for one at all times. [j_list_lock] 525 */ 526 struct journal_head *t_shadow_list; 527 528 /* 529 * Doubly-linked circular list of control buffers being written to the 530 * log. [j_list_lock] 531 */ 532 struct journal_head *t_log_list; 533 534 /* 535 * Protects info related to handles 536 */ 537 spinlock_t t_handle_lock; 538 539 /* 540 * Number of outstanding updates running on this transaction 541 * [t_handle_lock] 542 */ 543 int t_updates; 544 545 /* 546 * Number of buffers reserved for use by all handles in this transaction 547 * handle but not yet modified. [t_handle_lock] 548 */ 549 int t_outstanding_credits; 550 551 /* 552 * Forward and backward links for the circular list of all transactions 553 * awaiting checkpoint. [j_list_lock] 554 */ 555 transaction_t *t_cpnext, *t_cpprev; 556 557 /* 558 * When will the transaction expire (become due for commit), in jiffies? 559 * [no locking] 560 */ 561 unsigned long t_expires; 562 563 /* 564 * How many handles used this transaction? [t_handle_lock] 565 */ 566 int t_handle_count; 567 568}; 569 570/** 571 * struct journal_s - The journal_s type is the concrete type associated with 572 * journal_t. 573 * @j_flags: General journaling state flags 574 * @j_errno: Is there an outstanding uncleared error on the journal (from a 575 * prior abort)? 576 * @j_sb_buffer: First part of superblock buffer 577 * @j_superblock: Second part of superblock buffer 578 * @j_format_version: Version of the superblock format 579 * @j_state_lock: Protect the various scalars in the journal 580 * @j_barrier_count: Number of processes waiting to create a barrier lock 581 * @j_barrier: The barrier lock itself 582 * @j_running_transaction: The current running transaction.. 583 * @j_committing_transaction: the transaction we are pushing to disk 584 * @j_checkpoint_transactions: a linked circular list of all transactions 585 * waiting for checkpointing 586 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 587 * to start committing, or for a barrier lock to be released 588 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 589 * @j_wait_done_commit: Wait queue for waiting for commit to complete 590 * @j_wait_checkpoint: Wait queue to trigger checkpointing 591 * @j_wait_commit: Wait queue to trigger commit 592 * @j_wait_updates: Wait queue to wait for updates to complete 593 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 594 * @j_head: Journal head - identifies the first unused block in the journal 595 * @j_tail: Journal tail - identifies the oldest still-used block in the 596 * journal. 597 * @j_free: Journal free - how many free blocks are there in the journal? 598 * @j_first: The block number of the first usable block 599 * @j_last: The block number one beyond the last usable block 600 * @j_dev: Device where we store the journal 601 * @j_blocksize: blocksize for the location where we store the journal. 602 * @j_blk_offset: starting block offset for into the device where we store the 603 * journal 604 * @j_fs_dev: Device which holds the client fs. For internal journal this will 605 * be equal to j_dev 606 * @j_maxlen: Total maximum capacity of the journal region on disk. 607 * @j_list_lock: Protects the buffer lists and internal buffer state. 608 * @j_inode: Optional inode where we store the journal. If present, all journal 609 * block numbers are mapped into this inode via bmap(). 610 * @j_tail_sequence: Sequence number of the oldest transaction in the log 611 * @j_transaction_sequence: Sequence number of the next transaction to grant 612 * @j_commit_sequence: Sequence number of the most recently committed 613 * transaction 614 * @j_commit_request: Sequence number of the most recent transaction wanting 615 * commit 616 * @j_uuid: Uuid of client object. 617 * @j_task: Pointer to the current commit thread for this journal 618 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 619 * single compound commit transaction 620 * @j_commit_interval: What is the maximum transaction lifetime before we begin 621 * a commit? 622 * @j_commit_timer: The timer used to wakeup the commit thread 623 * @j_revoke_lock: Protect the revoke table 624 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 625 * current transaction. 626 * @j_revoke_table: alternate revoke tables for j_revoke 627 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 628 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 629 * number that will fit in j_blocksize 630 * @j_last_sync_writer: most recent pid which did a synchronous write 631 * @j_private: An opaque pointer to fs-private information. 632 */ 633 634struct journal_s 635{ 636 /* General journaling state flags [j_state_lock] */ 637 unsigned long j_flags; 638 639 /* 640 * Is there an outstanding uncleared error on the journal (from a prior 641 * abort)? [j_state_lock] 642 */ 643 int j_errno; 644 645 /* The superblock buffer */ 646 struct buffer_head *j_sb_buffer; 647 journal_superblock_t *j_superblock; 648 649 /* Version of the superblock format */ 650 int j_format_version; 651 652 /* 653 * Protect the various scalars in the journal 654 */ 655 spinlock_t j_state_lock; 656 657 /* 658 * Number of processes waiting to create a barrier lock [j_state_lock] 659 */ 660 int j_barrier_count; 661 662 /* The barrier lock itself */ 663 struct mutex j_barrier; 664 665 /* 666 * Transactions: The current running transaction... 667 * [j_state_lock] [caller holding open handle] 668 */ 669 transaction_t *j_running_transaction; 670 671 /* 672 * the transaction we are pushing to disk 673 * [j_state_lock] [caller holding open handle] 674 */ 675 transaction_t *j_committing_transaction; 676 677 /* 678 * ... and a linked circular list of all transactions waiting for 679 * checkpointing. [j_list_lock] 680 */ 681 transaction_t *j_checkpoint_transactions; 682 683 /* 684 * Wait queue for waiting for a locked transaction to start committing, 685 * or for a barrier lock to be released 686 */ 687 wait_queue_head_t j_wait_transaction_locked; 688 689 /* Wait queue for waiting for checkpointing to complete */ 690 wait_queue_head_t j_wait_logspace; 691 692 /* Wait queue for waiting for commit to complete */ 693 wait_queue_head_t j_wait_done_commit; 694 695 /* Wait queue to trigger checkpointing */ 696 wait_queue_head_t j_wait_checkpoint; 697 698 /* Wait queue to trigger commit */ 699 wait_queue_head_t j_wait_commit; 700 701 /* Wait queue to wait for updates to complete */ 702 wait_queue_head_t j_wait_updates; 703 704 /* Semaphore for locking against concurrent checkpoints */ 705 struct mutex j_checkpoint_mutex; 706 707 /* 708 * Journal head: identifies the first unused block in the journal. 709 * [j_state_lock] 710 */ 711 unsigned long j_head; 712 713 /* 714 * Journal tail: identifies the oldest still-used block in the journal. 715 * [j_state_lock] 716 */ 717 unsigned long j_tail; 718 719 /* 720 * Journal free: how many free blocks are there in the journal? 721 * [j_state_lock] 722 */ 723 unsigned long j_free; 724 725 /* 726 * Journal start and end: the block numbers of the first usable block 727 * and one beyond the last usable block in the journal. [j_state_lock] 728 */ 729 unsigned long j_first; 730 unsigned long j_last; 731 732 /* 733 * Device, blocksize and starting block offset for the location where we 734 * store the journal. 735 */ 736 struct block_device *j_dev; 737 int j_blocksize; 738 unsigned long long j_blk_offset; 739 740 /* 741 * Device which holds the client fs. For internal journal this will be 742 * equal to j_dev. 743 */ 744 struct block_device *j_fs_dev; 745 746 /* Total maximum capacity of the journal region on disk. */ 747 unsigned int j_maxlen; 748 749 /* 750 * Protects the buffer lists and internal buffer state. 751 */ 752 spinlock_t j_list_lock; 753 754 /* Optional inode where we store the journal. If present, all */ 755 /* journal block numbers are mapped into this inode via */ 756 /* bmap(). */ 757 struct inode *j_inode; 758 759 /* 760 * Sequence number of the oldest transaction in the log [j_state_lock] 761 */ 762 tid_t j_tail_sequence; 763 764 /* 765 * Sequence number of the next transaction to grant [j_state_lock] 766 */ 767 tid_t j_transaction_sequence; 768 769 /* 770 * Sequence number of the most recently committed transaction 771 * [j_state_lock]. 772 */ 773 tid_t j_commit_sequence; 774 775 /* 776 * Sequence number of the most recent transaction wanting commit 777 * [j_state_lock] 778 */ 779 tid_t j_commit_request; 780 781 /* 782 * Journal uuid: identifies the object (filesystem, LVM volume etc) 783 * backed by this journal. This will eventually be replaced by an array 784 * of uuids, allowing us to index multiple devices within a single 785 * journal and to perform atomic updates across them. 786 */ 787 __u8 j_uuid[16]; 788 789 /* Pointer to the current commit thread for this journal */ 790 struct task_struct *j_task; 791 792 /* 793 * Maximum number of metadata buffers to allow in a single compound 794 * commit transaction 795 */ 796 int j_max_transaction_buffers; 797 798 /* 799 * What is the maximum transaction lifetime before we begin a commit? 800 */ 801 unsigned long j_commit_interval; 802 803 /* The timer used to wakeup the commit thread: */ 804 struct timer_list j_commit_timer; 805 806 /* 807 * The revoke table: maintains the list of revoked blocks in the 808 * current transaction. [j_revoke_lock] 809 */ 810 spinlock_t j_revoke_lock; 811 struct jbd2_revoke_table_s *j_revoke; 812 struct jbd2_revoke_table_s *j_revoke_table[2]; 813 814 /* 815 * array of bhs for jbd2_journal_commit_transaction 816 */ 817 struct buffer_head **j_wbuf; 818 int j_wbufsize; 819 820 pid_t j_last_sync_writer; 821 822 /* 823 * An opaque pointer to fs-private information. ext3 puts its 824 * superblock pointer here 825 */ 826 void *j_private; 827}; 828 829/* 830 * Journal flag definitions 831 */ 832#define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 833#define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 834#define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 835#define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 836#define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 837#define JBD2_BARRIER 0x020 /* Use IDE barriers */ 838 839/* 840 * Function declarations for the journaling transaction and buffer 841 * management 842 */ 843 844/* Filing buffers */ 845extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 846extern void __jbd2_journal_unfile_buffer(struct journal_head *); 847extern void __jbd2_journal_refile_buffer(struct journal_head *); 848extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 849extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 850extern void __journal_free_buffer(struct journal_head *bh); 851extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 852extern void __journal_clean_data_list(transaction_t *transaction); 853 854/* Log buffer allocation */ 855extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 856int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 857 858/* Commit management */ 859extern void jbd2_journal_commit_transaction(journal_t *); 860 861/* Checkpoint list management */ 862int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 863int __jbd2_journal_remove_checkpoint(struct journal_head *); 864void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 865 866/* Buffer IO */ 867extern int 868jbd2_journal_write_metadata_buffer(transaction_t *transaction, 869 struct journal_head *jh_in, 870 struct journal_head **jh_out, 871 unsigned long long blocknr); 872 873/* Transaction locking */ 874extern void __wait_on_journal (journal_t *); 875 876/* 877 * Journal locking. 878 * 879 * We need to lock the journal during transaction state changes so that nobody 880 * ever tries to take a handle on the running transaction while we are in the 881 * middle of moving it to the commit phase. j_state_lock does this. 882 * 883 * Note that the locking is completely interrupt unsafe. We never touch 884 * journal structures from interrupts. 885 */ 886 887static inline handle_t *journal_current_handle(void) 888{ 889 return current->journal_info; 890} 891 892/* The journaling code user interface: 893 * 894 * Create and destroy handles 895 * Register buffer modifications against the current transaction. 896 */ 897 898extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 899extern int jbd2_journal_restart (handle_t *, int nblocks); 900extern int jbd2_journal_extend (handle_t *, int nblocks); 901extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 902extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 903extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 904extern int jbd2_journal_dirty_data (handle_t *, struct buffer_head *); 905extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 906extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 907extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 908extern void journal_sync_buffer (struct buffer_head *); 909extern void jbd2_journal_invalidatepage(journal_t *, 910 struct page *, unsigned long); 911extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 912extern int jbd2_journal_stop(handle_t *); 913extern int jbd2_journal_flush (journal_t *); 914extern void jbd2_journal_lock_updates (journal_t *); 915extern void jbd2_journal_unlock_updates (journal_t *); 916 917extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 918 struct block_device *fs_dev, 919 unsigned long long start, int len, int bsize); 920extern journal_t * jbd2_journal_init_inode (struct inode *); 921extern int jbd2_journal_update_format (journal_t *); 922extern int jbd2_journal_check_used_features 923 (journal_t *, unsigned long, unsigned long, unsigned long); 924extern int jbd2_journal_check_available_features 925 (journal_t *, unsigned long, unsigned long, unsigned long); 926extern int jbd2_journal_set_features 927 (journal_t *, unsigned long, unsigned long, unsigned long); 928extern int jbd2_journal_create (journal_t *); 929extern int jbd2_journal_load (journal_t *journal); 930extern void jbd2_journal_destroy (journal_t *); 931extern int jbd2_journal_recover (journal_t *journal); 932extern int jbd2_journal_wipe (journal_t *, int); 933extern int jbd2_journal_skip_recovery (journal_t *); 934extern void jbd2_journal_update_superblock (journal_t *, int); 935extern void __jbd2_journal_abort_hard (journal_t *); 936extern void jbd2_journal_abort (journal_t *, int); 937extern int jbd2_journal_errno (journal_t *); 938extern void jbd2_journal_ack_err (journal_t *); 939extern int jbd2_journal_clear_err (journal_t *); 940extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 941extern int jbd2_journal_force_commit(journal_t *); 942 943/* 944 * journal_head management 945 */ 946struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 947struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 948void jbd2_journal_remove_journal_head(struct buffer_head *bh); 949void jbd2_journal_put_journal_head(struct journal_head *jh); 950 951/* 952 * handle management 953 */ 954extern struct kmem_cache *jbd2_handle_cache; 955 956static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) 957{ 958 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 959} 960 961static inline void jbd_free_handle(handle_t *handle) 962{ 963 kmem_cache_free(jbd2_handle_cache, handle); 964} 965 966/* Primary revoke support */ 967#define JOURNAL_REVOKE_DEFAULT_HASH 256 968extern int jbd2_journal_init_revoke(journal_t *, int); 969extern void jbd2_journal_destroy_revoke_caches(void); 970extern int jbd2_journal_init_revoke_caches(void); 971 972extern void jbd2_journal_destroy_revoke(journal_t *); 973extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 974extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 975extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *); 976 977/* Recovery revoke support */ 978extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 979extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 980extern void jbd2_journal_clear_revoke(journal_t *); 981extern void jbd2_journal_switch_revoke_table(journal_t *journal); 982 983/* 984 * The log thread user interface: 985 * 986 * Request space in the current transaction, and force transaction commit 987 * transitions on demand. 988 */ 989 990int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 991int jbd2_log_start_commit(journal_t *journal, tid_t tid); 992int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 993int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 994int jbd2_journal_force_commit_nested(journal_t *journal); 995int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 996int jbd2_log_do_checkpoint(journal_t *journal); 997 998void __jbd2_log_wait_for_space(journal_t *journal); 999extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1000extern int jbd2_cleanup_journal_tail(journal_t *); 1001 1002/* Debugging code only: */ 1003 1004#define jbd_ENOSYS() \ 1005do { \ 1006 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \ 1007 current->state = TASK_UNINTERRUPTIBLE; \ 1008 schedule(); \ 1009} while (1) 1010 1011/* 1012 * is_journal_abort 1013 * 1014 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1015 * bit, when set, indicates that we have had a fatal error somewhere, 1016 * either inside the journaling layer or indicated to us by the client 1017 * (eg. ext3), and that we and should not commit any further 1018 * transactions. 1019 */ 1020 1021static inline int is_journal_aborted(journal_t *journal) 1022{ 1023 return journal->j_flags & JBD2_ABORT; 1024} 1025 1026static inline int is_handle_aborted(handle_t *handle) 1027{ 1028 if (handle->h_aborted) 1029 return 1; 1030 return is_journal_aborted(handle->h_transaction->t_journal); 1031} 1032 1033static inline void jbd2_journal_abort_handle(handle_t *handle) 1034{ 1035 handle->h_aborted = 1; 1036} 1037 1038#endif /* __KERNEL__ */ 1039 1040/* Comparison functions for transaction IDs: perform comparisons using 1041 * modulo arithmetic so that they work over sequence number wraps. */ 1042 1043static inline int tid_gt(tid_t x, tid_t y) 1044{ 1045 int difference = (x - y); 1046 return (difference > 0); 1047} 1048 1049static inline int tid_geq(tid_t x, tid_t y) 1050{ 1051 int difference = (x - y); 1052 return (difference >= 0); 1053} 1054 1055extern int jbd2_journal_blocks_per_page(struct inode *inode); 1056extern size_t journal_tag_bytes(journal_t *journal); 1057 1058/* 1059 * Return the minimum number of blocks which must be free in the journal 1060 * before a new transaction may be started. Must be called under j_state_lock. 1061 */ 1062static inline int jbd_space_needed(journal_t *journal) 1063{ 1064 int nblocks = journal->j_max_transaction_buffers; 1065 if (journal->j_committing_transaction) 1066 nblocks += journal->j_committing_transaction-> 1067 t_outstanding_credits; 1068 return nblocks; 1069} 1070 1071/* 1072 * Definitions which augment the buffer_head layer 1073 */ 1074 1075/* journaling buffer types */ 1076#define BJ_None 0 /* Not journaled */ 1077#define BJ_SyncData 1 /* Normal data: flush before commit */ 1078#define BJ_Metadata 2 /* Normal journaled metadata */ 1079#define BJ_Forget 3 /* Buffer superseded by this transaction */ 1080#define BJ_IO 4 /* Buffer is for temporary IO use */ 1081#define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1082#define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1083#define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1084#define BJ_Locked 8 /* Locked for I/O during commit */ 1085#define BJ_Types 9 1086 1087extern int jbd_blocks_per_page(struct inode *inode); 1088 1089#ifdef __KERNEL__ 1090 1091#define buffer_trace_init(bh) do {} while (0) 1092#define print_buffer_fields(bh) do {} while (0) 1093#define print_buffer_trace(bh) do {} while (0) 1094#define BUFFER_TRACE(bh, info) do {} while (0) 1095#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1096#define JBUFFER_TRACE(jh, info) do {} while (0) 1097 1098#endif /* __KERNEL__ */ 1099 1100#endif /* _LINUX_JBD_H */ 1101