1 /* 2 * linux/include/linux/jbd.h 3 * 4 * Written by Stephen C. Tweedie <sct (at) redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16 #ifndef _LINUX_JBD_H 17 #define _LINUX_JBD_H 18 19 /* 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/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 60 extern int journal_enable_debug; 61 62 #define jbd_debug(n, f, a...) \ 63 do { \ 64 if ((n) <= 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 74 extern void * __jbd_kmalloc (const char *where, size_t size, gfp_t flags, int retry); 75 extern void * jbd_slab_alloc(size_t size, gfp_t flags); 76 extern void jbd_slab_free(void *ptr, size_t size); 77 78 #define jbd_kmalloc(size, flags) \ 79 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry) 80 #define jbd_rep_kmalloc(size, flags) \ 81 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1) 82 83 #define JFS_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 **/ 104 typedef 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 **/ 118 typedef struct journal_s journal_t; /* Journal control structure */ 119 #endif 120 121 /* 122 * Internal structures used by the logging mechanism: 123 */ 124 125 #define JFS_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 JFS_DESCRIPTOR_BLOCK 1 136 #define JFS_COMMIT_BLOCK 2 137 #define JFS_SUPERBLOCK_V1 3 138 #define JFS_SUPERBLOCK_V2 4 139 #define JFS_REVOKE_BLOCK 5 140 141 /* 142 * Standard header for all descriptor blocks: 143 */ 144 typedef 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 */ 155 typedef struct journal_block_tag_s 156 { 157 __be32 t_blocknr; /* The on-disk block number */ 158 __be32 t_flags; /* See below */ 159 } journal_block_tag_t; 160 161 /* 162 * The revoke descriptor: used on disk to describe a series of blocks to 163 * be revoked from the log 164 */ 165 typedef struct journal_revoke_header_s 166 { 167 journal_header_t r_header; 168 __be32 r_count; /* Count of bytes used in the block */ 169 } journal_revoke_header_t; 170 171 172 /* Definitions for the journal tag flags word: */ 173 #define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 174 #define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 175 #define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 176 #define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 177 178 179 /* 180 * The journal superblock. All fields are in big-endian byte order. 181 */ 182 typedef struct journal_superblock_s 183 { 184 /* 0x0000 */ 185 journal_header_t s_header; 186 187 /* 0x000C */ 188 /* Static information describing the journal */ 189 __be32 s_blocksize; /* journal device blocksize */ 190 __be32 s_maxlen; /* total blocks in journal file */ 191 __be32 s_first; /* first block of log information */ 192 193 /* 0x0018 */ 194 /* Dynamic information describing the current state of the log */ 195 __be32 s_sequence; /* first commit ID expected in log */ 196 __be32 s_start; /* blocknr of start of log */ 197 198 /* 0x0020 */ 199 /* Error value, as set by journal_abort(). */ 200 __be32 s_errno; 201 202 /* 0x0024 */ 203 /* Remaining fields are only valid in a version-2 superblock */ 204 __be32 s_feature_compat; /* compatible feature set */ 205 __be32 s_feature_incompat; /* incompatible feature set */ 206 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 207 /* 0x0030 */ 208 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 209 210 /* 0x0040 */ 211 __be32 s_nr_users; /* Nr of filesystems sharing log */ 212 213 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 214 215 /* 0x0048 */ 216 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 217 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 218 219 /* 0x0050 */ 220 __u32 s_padding[44]; 221 222 /* 0x0100 */ 223 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 224 /* 0x0400 */ 225 } journal_superblock_t; 226 227 #define JFS_HAS_COMPAT_FEATURE(j,mask) \ 228 ((j)->j_format_version >= 2 && \ 229 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 230 #define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 231 ((j)->j_format_version >= 2 && \ 232 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 233 #define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 234 ((j)->j_format_version >= 2 && \ 235 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 236 237 #define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 238 239 /* Features known to this kernel version: */ 240 #define JFS_KNOWN_COMPAT_FEATURES 0 241 #define JFS_KNOWN_ROCOMPAT_FEATURES 0 242 #define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE 243 244 #ifdef __KERNEL__ 245 246 #include <linux/fs.h> 247 #include <linux/sched.h> 248 249 #define JBD_ASSERTIONS 250 #ifdef JBD_ASSERTIONS 251 #define J_ASSERT(assert) \ 252 do { \ 253 if (!(assert)) { \ 254 printk (KERN_EMERG \ 255 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 256 __FUNCTION__, __FILE__, __LINE__, # assert); \ 257 BUG(); \ 258 } \ 259 } while (0) 260 261 #if defined(CONFIG_BUFFER_DEBUG) 262 void buffer_assertion_failure(struct buffer_head *bh); 263 #define J_ASSERT_BH(bh, expr) \ 264 do { \ 265 if (!(expr)) \ 266 buffer_assertion_failure(bh); \ 267 J_ASSERT(expr); \ 268 } while (0) 269 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 270 #else 271 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 272 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 273 #endif 274 275 #else 276 #define J_ASSERT(assert) do { } while (0) 277 #endif /* JBD_ASSERTIONS */ 278 279 #if defined(JBD_PARANOID_IOFAIL) 280 #define J_EXPECT(expr, why...) J_ASSERT(expr) 281 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 282 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 283 #else 284 #define __journal_expect(expr, why...) \ 285 ({ \ 286 int val = (expr); \ 287 if (!val) { \ 288 printk(KERN_ERR \ 289 "EXT3-fs unexpected failure: %s;\n",# expr); \ 290 printk(KERN_ERR why "\n"); \ 291 } \ 292 val; \ 293 }) 294 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 295 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 296 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 297 #endif 298 299 enum jbd_state_bits { 300 BH_JBD /* Has an attached ext3 journal_head */ 301 = BH_PrivateStart, 302 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 303 BH_Freed, /* Has been freed (truncated) */ 304 BH_Revoked, /* Has been revoked from the log */ 305 BH_RevokeValid, /* Revoked flag is valid */ 306 BH_JBDDirty, /* Is dirty but journaled */ 307 BH_State, /* Pins most journal_head state */ 308 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 309 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 310 }; 311 312 BUFFER_FNS(JBD, jbd) 313 BUFFER_FNS(JWrite, jwrite) 314 BUFFER_FNS(JBDDirty, jbddirty) 315 TAS_BUFFER_FNS(JBDDirty, jbddirty) 316 BUFFER_FNS(Revoked, revoked) 317 TAS_BUFFER_FNS(Revoked, revoked) 318 BUFFER_FNS(RevokeValid, revokevalid) 319 TAS_BUFFER_FNS(RevokeValid, revokevalid) 320 BUFFER_FNS(Freed, freed) 321 322 static inline struct buffer_head *jh2bh(struct journal_head *jh) 323 { 324 return jh->b_bh; 325 } 326 327 static inline struct journal_head *bh2jh(struct buffer_head *bh) 328 { 329 return bh->b_private; 330 } 331 332 static inline void jbd_lock_bh_state(struct buffer_head *bh) 333 { 334 bit_spin_lock(BH_State, &bh->b_state); 335 } 336 337 static inline int jbd_trylock_bh_state(struct buffer_head *bh) 338 { 339 return bit_spin_trylock(BH_State, &bh->b_state); 340 } 341 342 static inline int jbd_is_locked_bh_state(struct buffer_head *bh) 343 { 344 return bit_spin_is_locked(BH_State, &bh->b_state); 345 } 346 347 static inline void jbd_unlock_bh_state(struct buffer_head *bh) 348 { 349 bit_spin_unlock(BH_State, &bh->b_state); 350 } 351 352 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 353 { 354 bit_spin_lock(BH_JournalHead, &bh->b_state); 355 } 356 357 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 358 { 359 bit_spin_unlock(BH_JournalHead, &bh->b_state); 360 } 361 362 struct jbd_revoke_table_s; 363 364 /** 365 * struct handle_s - The handle_s type is the concrete type associated with 366 * handle_t. 367 * @h_transaction: Which compound transaction is this update a part of? 368 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 369 * @h_ref: Reference count on this handle 370 * @h_err: Field for caller's use to track errors through large fs operations 371 * @h_sync: flag for sync-on-close 372 * @h_jdata: flag to force data journaling 373 * @h_aborted: flag indicating fatal error on handle 374 **/ 375 376 /* Docbook can't yet cope with the bit fields, but will leave the documentation 377 * in so it can be fixed later. 378 */ 379 380 struct handle_s 381 { 382 /* Which compound transaction is this update a part of? */ 383 transaction_t *h_transaction; 384 385 /* Number of remaining buffers we are allowed to dirty: */ 386 int h_buffer_credits; 387 388 /* Reference count on this handle */ 389 int h_ref; 390 391 /* Field for caller's use to track errors through large fs */ 392 /* operations */ 393 int h_err; 394 395 /* Flags [no locking] */ 396 unsigned int h_sync: 1; /* sync-on-close */ 397 unsigned int h_jdata: 1; /* force data journaling */ 398 unsigned int h_aborted: 1; /* fatal error on handle */ 399 }; 400 401 402 /* The transaction_t type is the guts of the journaling mechanism. It 403 * tracks a compound transaction through its various states: 404 * 405 * RUNNING: accepting new updates 406 * LOCKED: Updates still running but we don't accept new ones 407 * RUNDOWN: Updates are tidying up but have finished requesting 408 * new buffers to modify (state not used for now) 409 * FLUSH: All updates complete, but we are still writing to disk 410 * COMMIT: All data on disk, writing commit record 411 * FINISHED: We still have to keep the transaction for checkpointing. 412 * 413 * The transaction keeps track of all of the buffers modified by a 414 * running transaction, and all of the buffers committed but not yet 415 * flushed to home for finished transactions. 416 */ 417 418 /* 419 * Lock ranking: 420 * 421 * j_list_lock 422 * ->jbd_lock_bh_journal_head() (This is "innermost") 423 * 424 * j_state_lock 425 * ->jbd_lock_bh_state() 426 * 427 * jbd_lock_bh_state() 428 * ->j_list_lock 429 * 430 * j_state_lock 431 * ->t_handle_lock 432 * 433 * j_state_lock 434 * ->j_list_lock (journal_unmap_buffer) 435 * 436 */ 437 438 struct transaction_s 439 { 440 /* Pointer to the journal for this transaction. [no locking] */ 441 journal_t *t_journal; 442 443 /* Sequence number for this transaction [no locking] */ 444 tid_t t_tid; 445 446 /* 447 * Transaction's current state 448 * [no locking - only kjournald alters this] 449 * FIXME: needs barriers 450 * KLUDGE: [use j_state_lock] 451 */ 452 enum { 453 T_RUNNING, 454 T_LOCKED, 455 T_RUNDOWN, 456 T_FLUSH, 457 T_COMMIT, 458 T_FINISHED 459 } t_state; 460 461 /* 462 * Where in the log does this transaction's commit start? [no locking] 463 */ 464 unsigned long t_log_start; 465 466 /* Number of buffers on the t_buffers list [j_list_lock] */ 467 int t_nr_buffers; 468 469 /* 470 * Doubly-linked circular list of all buffers reserved but not yet 471 * modified by this transaction [j_list_lock] 472 */ 473 struct journal_head *t_reserved_list; 474 475 /* 476 * Doubly-linked circular list of all buffers under writeout during 477 * commit [j_list_lock] 478 */ 479 struct journal_head *t_locked_list; 480 481 /* 482 * Doubly-linked circular list of all metadata buffers owned by this 483 * transaction [j_list_lock] 484 */ 485 struct journal_head *t_buffers; 486 487 /* 488 * Doubly-linked circular list of all data buffers still to be 489 * flushed before this transaction can be committed [j_list_lock] 490 */ 491 struct journal_head *t_sync_datalist; 492 493 /* 494 * Doubly-linked circular list of all forget buffers (superseded 495 * buffers which we can un-checkpoint once this transaction commits) 496 * [j_list_lock] 497 */ 498 struct journal_head *t_forget; 499 500 /* 501 * Doubly-linked circular list of all buffers still to be flushed before 502 * this transaction can be checkpointed. [j_list_lock] 503 */ 504 struct journal_head *t_checkpoint_list; 505 506 /* 507 * Doubly-linked circular list of all buffers submitted for IO while 508 * checkpointing. [j_list_lock] 509 */ 510 struct journal_head *t_checkpoint_io_list; 511 512 /* 513 * Doubly-linked circular list of temporary buffers currently undergoing 514 * IO in the log [j_list_lock] 515 */ 516 struct journal_head *t_iobuf_list; 517 518 /* 519 * Doubly-linked circular list of metadata buffers being shadowed by log 520 * IO. The IO buffers on the iobuf list and the shadow buffers on this 521 * list match each other one for one at all times. [j_list_lock] 522 */ 523 struct journal_head *t_shadow_list; 524 525 /* 526 * Doubly-linked circular list of control buffers being written to the 527 * log. [j_list_lock] 528 */ 529 struct journal_head *t_log_list; 530 531 /* 532 * Protects info related to handles 533 */ 534 spinlock_t t_handle_lock; 535 536 /* 537 * Number of outstanding updates running on this transaction 538 * [t_handle_lock] 539 */ 540 int t_updates; 541 542 /* 543 * Number of buffers reserved for use by all handles in this transaction 544 * handle but not yet modified. [t_handle_lock] 545 */ 546 int t_outstanding_credits; 547 548 /* 549 * Forward and backward links for the circular list of all transactions 550 * awaiting checkpoint. [j_list_lock] 551 */ 552 transaction_t *t_cpnext, *t_cpprev; 553 554 /* 555 * When will the transaction expire (become due for commit), in jiffies? 556 * [no locking] 557 */ 558 unsigned long t_expires; 559 560 /* 561 * How many handles used this transaction? [t_handle_lock] 562 */ 563 int t_handle_count; 564 565 }; 566 567 /** 568 * struct journal_s - The journal_s type is the concrete type associated with 569 * journal_t. 570 * @j_flags: General journaling state flags 571 * @j_errno: Is there an outstanding uncleared error on the journal (from a 572 * prior abort)? 573 * @j_sb_buffer: First part of superblock buffer 574 * @j_superblock: Second part of superblock buffer 575 * @j_format_version: Version of the superblock format 576 * @j_state_lock: Protect the various scalars in the journal 577 * @j_barrier_count: Number of processes waiting to create a barrier lock 578 * @j_barrier: The barrier lock itself 579 * @j_running_transaction: The current running transaction.. 580 * @j_committing_transaction: the transaction we are pushing to disk 581 * @j_checkpoint_transactions: a linked circular list of all transactions 582 * waiting for checkpointing 583 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 584 * to start committing, or for a barrier lock to be released 585 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 586 * @j_wait_done_commit: Wait queue for waiting for commit to complete 587 * @j_wait_checkpoint: Wait queue to trigger checkpointing 588 * @j_wait_commit: Wait queue to trigger commit 589 * @j_wait_updates: Wait queue to wait for updates to complete 590 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 591 * @j_head: Journal head - identifies the first unused block in the journal 592 * @j_tail: Journal tail - identifies the oldest still-used block in the 593 * journal. 594 * @j_free: Journal free - how many free blocks are there in the journal? 595 * @j_first: The block number of the first usable block 596 * @j_last: The block number one beyond the last usable block 597 * @j_dev: Device where we store the journal 598 * @j_blocksize: blocksize for the location where we store the journal. 599 * @j_blk_offset: starting block offset for into the device where we store the 600 * journal 601 * @j_fs_dev: Device which holds the client fs. For internal journal this will 602 * be equal to j_dev 603 * @j_maxlen: Total maximum capacity of the journal region on disk. 604 * @j_list_lock: Protects the buffer lists and internal buffer state. 605 * @j_inode: Optional inode where we store the journal. If present, all journal 606 * block numbers are mapped into this inode via bmap(). 607 * @j_tail_sequence: Sequence number of the oldest transaction in the log 608 * @j_transaction_sequence: Sequence number of the next transaction to grant 609 * @j_commit_sequence: Sequence number of the most recently committed 610 * transaction 611 * @j_commit_request: Sequence number of the most recent transaction wanting 612 * commit 613 * @j_uuid: Uuid of client object. 614 * @j_task: Pointer to the current commit thread for this journal 615 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 616 * single compound commit transaction 617 * @j_commit_interval: What is the maximum transaction lifetime before we begin 618 * a commit? 619 * @j_commit_timer: The timer used to wakeup the commit thread 620 * @j_revoke_lock: Protect the revoke table 621 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 622 * current transaction. 623 * @j_revoke_table: alternate revoke tables for j_revoke 624 * @j_wbuf: array of buffer_heads for journal_commit_transaction 625 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 626 * number that will fit in j_blocksize 627 * @j_last_sync_writer: most recent pid which did a synchronous write 628 * @j_private: An opaque pointer to fs-private information. 629 */ 630 631 struct journal_s 632 { 633 /* General journaling state flags [j_state_lock] */ 634 unsigned long j_flags; 635 636 /* 637 * Is there an outstanding uncleared error on the journal (from a prior 638 * abort)? [j_state_lock] 639 */ 640 int j_errno; 641 642 /* The superblock buffer */ 643 struct buffer_head *j_sb_buffer; 644 journal_superblock_t *j_superblock; 645 646 /* Version of the superblock format */ 647 int j_format_version; 648 649 /* 650 * Protect the various scalars in the journal 651 */ 652 spinlock_t j_state_lock; 653 654 /* 655 * Number of processes waiting to create a barrier lock [j_state_lock] 656 */ 657 int j_barrier_count; 658 659 /* The barrier lock itself */ 660 struct mutex j_barrier; 661 662 /* 663 * Transactions: The current running transaction... 664 * [j_state_lock] [caller holding open handle] 665 */ 666 transaction_t *j_running_transaction; 667 668 /* 669 * the transaction we are pushing to disk 670 * [j_state_lock] [caller holding open handle] 671 */ 672 transaction_t *j_committing_transaction; 673 674 /* 675 * ... and a linked circular list of all transactions waiting for 676 * checkpointing. [j_list_lock] 677 */ 678 transaction_t *j_checkpoint_transactions; 679 680 /* 681 * Wait queue for waiting for a locked transaction to start committing, 682 * or for a barrier lock to be released 683 */ 684 wait_queue_head_t j_wait_transaction_locked; 685 686 /* Wait queue for waiting for checkpointing to complete */ 687 wait_queue_head_t j_wait_logspace; 688 689 /* Wait queue for waiting for commit to complete */ 690 wait_queue_head_t j_wait_done_commit; 691 692 /* Wait queue to trigger checkpointing */ 693 wait_queue_head_t j_wait_checkpoint; 694 695 /* Wait queue to trigger commit */ 696 wait_queue_head_t j_wait_commit; 697 698 /* Wait queue to wait for updates to complete */ 699 wait_queue_head_t j_wait_updates; 700 701 /* Semaphore for locking against concurrent checkpoints */ 702 struct mutex j_checkpoint_mutex; 703 704 /* 705 * Journal head: identifies the first unused block in the journal. 706 * [j_state_lock] 707 */ 708 unsigned long j_head; 709 710 /* 711 * Journal tail: identifies the oldest still-used block in the journal. 712 * [j_state_lock] 713 */ 714 unsigned long j_tail; 715 716 /* 717 * Journal free: how many free blocks are there in the journal? 718 * [j_state_lock] 719 */ 720 unsigned long j_free; 721 722 /* 723 * Journal start and end: the block numbers of the first usable block 724 * and one beyond the last usable block in the journal. [j_state_lock] 725 */ 726 unsigned long j_first; 727 unsigned long j_last; 728 729 /* 730 * Device, blocksize and starting block offset for the location where we 731 * store the journal. 732 */ 733 struct block_device *j_dev; 734 int j_blocksize; 735 unsigned int j_blk_offset; 736 737 /* 738 * Device which holds the client fs. For internal journal this will be 739 * equal to j_dev. 740 */ 741 struct block_device *j_fs_dev; 742 743 /* Total maximum capacity of the journal region on disk. */ 744 unsigned int j_maxlen; 745 746 /* 747 * Protects the buffer lists and internal buffer state. 748 */ 749 spinlock_t j_list_lock; 750 751 /* Optional inode where we store the journal. If present, all */ 752 /* journal block numbers are mapped into this inode via */ 753 /* bmap(). */ 754 struct inode *j_inode; 755 756 /* 757 * Sequence number of the oldest transaction in the log [j_state_lock] 758 */ 759 tid_t j_tail_sequence; 760 761 /* 762 * Sequence number of the next transaction to grant [j_state_lock] 763 */ 764 tid_t j_transaction_sequence; 765 766 /* 767 * Sequence number of the most recently committed transaction 768 * [j_state_lock]. 769 */ 770 tid_t j_commit_sequence; 771 772 /* 773 * Sequence number of the most recent transaction wanting commit 774 * [j_state_lock] 775 */ 776 tid_t j_commit_request; 777 778 /* 779 * Journal uuid: identifies the object (filesystem, LVM volume etc) 780 * backed by this journal. This will eventually be replaced by an array 781 * of uuids, allowing us to index multiple devices within a single 782 * journal and to perform atomic updates across them. 783 */ 784 __u8 j_uuid[16]; 785 786 /* Pointer to the current commit thread for this journal */ 787 struct task_struct *j_task; 788 789 /* 790 * Maximum number of metadata buffers to allow in a single compound 791 * commit transaction 792 */ 793 int j_max_transaction_buffers; 794 795 /* 796 * What is the maximum transaction lifetime before we begin a commit? 797 */ 798 unsigned long j_commit_interval; 799 800 /* The timer used to wakeup the commit thread: */ 801 struct timer_list j_commit_timer; 802 803 /* 804 * The revoke table: maintains the list of revoked blocks in the 805 * current transaction. [j_revoke_lock] 806 */ 807 spinlock_t j_revoke_lock; 808 struct jbd_revoke_table_s *j_revoke; 809 struct jbd_revoke_table_s *j_revoke_table[2]; 810 811 /* 812 * array of bhs for journal_commit_transaction 813 */ 814 struct buffer_head **j_wbuf; 815 int j_wbufsize; 816 817 pid_t j_last_sync_writer; 818 819 /* 820 * An opaque pointer to fs-private information. ext3 puts its 821 * superblock pointer here 822 */ 823 void *j_private; 824 }; 825 826 /* 827 * Journal flag definitions 828 */ 829 #define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 830 #define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 831 #define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 832 #define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 833 #define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 834 #define JFS_BARRIER 0x020 /* Use IDE barriers */ 835 836 /* 837 * Function declarations for the journaling transaction and buffer 838 * management 839 */ 840 841 /* Filing buffers */ 842 extern void __journal_temp_unlink_buffer(struct journal_head *jh); 843 extern void journal_unfile_buffer(journal_t *, struct journal_head *); 844 extern void __journal_unfile_buffer(struct journal_head *); 845 extern void __journal_refile_buffer(struct journal_head *); 846 extern void journal_refile_buffer(journal_t *, struct journal_head *); 847 extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 848 extern void __journal_free_buffer(struct journal_head *bh); 849 extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 850 extern void __journal_clean_data_list(transaction_t *transaction); 851 852 /* Log buffer allocation */ 853 extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 854 int journal_next_log_block(journal_t *, unsigned long *); 855 856 /* Commit management */ 857 extern void journal_commit_transaction(journal_t *); 858 859 /* Checkpoint list management */ 860 int __journal_clean_checkpoint_list(journal_t *journal); 861 int __journal_remove_checkpoint(struct journal_head *); 862 void __journal_insert_checkpoint(struct journal_head *, transaction_t *); 863 864 /* Buffer IO */ 865 extern int 866 journal_write_metadata_buffer(transaction_t *transaction, 867 struct journal_head *jh_in, 868 struct journal_head **jh_out, 869 int blocknr); 870 871 /* Transaction locking */ 872 extern void __wait_on_journal (journal_t *); 873 874 /* 875 * Journal locking. 876 * 877 * We need to lock the journal during transaction state changes so that nobody 878 * ever tries to take a handle on the running transaction while we are in the 879 * middle of moving it to the commit phase. j_state_lock does this. 880 * 881 * Note that the locking is completely interrupt unsafe. We never touch 882 * journal structures from interrupts. 883 */ 884 885 static inline handle_t *journal_current_handle(void) 886 { 887 return current->journal_info; 888 } 889 890 /* The journaling code user interface: 891 * 892 * Create and destroy handles 893 * Register buffer modifications against the current transaction. 894 */ 895 896 extern handle_t *journal_start(journal_t *, int nblocks); 897 extern int journal_restart (handle_t *, int nblocks); 898 extern int journal_extend (handle_t *, int nblocks); 899 extern int journal_get_write_access(handle_t *, struct buffer_head *); 900 extern int journal_get_create_access (handle_t *, struct buffer_head *); 901 extern int journal_get_undo_access(handle_t *, struct buffer_head *); 902 extern int journal_dirty_data (handle_t *, struct buffer_head *); 903 extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 904 extern void journal_release_buffer (handle_t *, struct buffer_head *); 905 extern int journal_forget (handle_t *, struct buffer_head *); 906 extern void journal_sync_buffer (struct buffer_head *); 907 extern void journal_invalidatepage(journal_t *, 908 struct page *, unsigned long); 909 extern int journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 910 extern int journal_stop(handle_t *); 911 extern int journal_flush (journal_t *); 912 extern void journal_lock_updates (journal_t *); 913 extern void journal_unlock_updates (journal_t *); 914 915 extern journal_t * journal_init_dev(struct block_device *bdev, 916 struct block_device *fs_dev, 917 int start, int len, int bsize); 918 extern journal_t * journal_init_inode (struct inode *); 919 extern int journal_update_format (journal_t *); 920 extern int journal_check_used_features 921 (journal_t *, unsigned long, unsigned long, unsigned long); 922 extern int journal_check_available_features 923 (journal_t *, unsigned long, unsigned long, unsigned long); 924 extern int journal_set_features 925 (journal_t *, unsigned long, unsigned long, unsigned long); 926 extern int journal_create (journal_t *); 927 extern int journal_load (journal_t *journal); 928 extern void journal_destroy (journal_t *); 929 extern int journal_recover (journal_t *journal); 930 extern int journal_wipe (journal_t *, int); 931 extern int journal_skip_recovery (journal_t *); 932 extern void journal_update_superblock (journal_t *, int); 933 extern void __journal_abort_hard (journal_t *); 934 extern void journal_abort (journal_t *, int); 935 extern int journal_errno (journal_t *); 936 extern void journal_ack_err (journal_t *); 937 extern int journal_clear_err (journal_t *); 938 extern int journal_bmap(journal_t *, unsigned long, unsigned long *); 939 extern int journal_force_commit(journal_t *); 940 941 /* 942 * journal_head management 943 */ 944 struct journal_head *journal_add_journal_head(struct buffer_head *bh); 945 struct journal_head *journal_grab_journal_head(struct buffer_head *bh); 946 void journal_remove_journal_head(struct buffer_head *bh); 947 void journal_put_journal_head(struct journal_head *jh); 948 949 /* 950 * handle management 951 */ 952 extern kmem_cache_t *jbd_handle_cache; 953 954 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) 955 { 956 return kmem_cache_alloc(jbd_handle_cache, gfp_flags); 957 } 958 959 static inline void jbd_free_handle(handle_t *handle) 960 { 961 kmem_cache_free(jbd_handle_cache, handle); 962 } 963 964 /* Primary revoke support */ 965 #define JOURNAL_REVOKE_DEFAULT_HASH 256 966 extern int journal_init_revoke(journal_t *, int); 967 extern void journal_destroy_revoke_caches(void); 968 extern int journal_init_revoke_caches(void); 969 970 extern void journal_destroy_revoke(journal_t *); 971 extern int journal_revoke (handle_t *, 972 unsigned long, struct buffer_head *); 973 extern int journal_cancel_revoke(handle_t *, struct journal_head *); 974 extern void journal_write_revoke_records(journal_t *, transaction_t *); 975 976 /* Recovery revoke support */ 977 extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 978 extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 979 extern void journal_clear_revoke(journal_t *); 980 extern void journal_brelse_array(struct buffer_head *b[], int n); 981 extern void 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 */ 989 990 int __log_space_left(journal_t *); /* Called with journal locked */ 991 int log_start_commit(journal_t *journal, tid_t tid); 992 int __log_start_commit(journal_t *journal, tid_t tid); 993 int journal_start_commit(journal_t *journal, tid_t *tid); 994 int journal_force_commit_nested(journal_t *journal); 995 int log_wait_commit(journal_t *journal, tid_t tid); 996 int log_do_checkpoint(journal_t *journal); 997 998 void __log_wait_for_space(journal_t *journal); 999 extern void __journal_drop_transaction(journal_t *, transaction_t *); 1000 extern int cleanup_journal_tail(journal_t *); 1001 1002 /* Debugging code only: */ 1003 1004 #define jbd_ENOSYS() \ 1005 do { \ 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 JFS_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 1021 static inline int is_journal_aborted(journal_t *journal) 1022 { 1023 return journal->j_flags & JFS_ABORT; 1024 } 1025 1026 static 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 1033 static inline void 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 1043 static inline int tid_gt(tid_t x, tid_t y) 1044 { 1045 int difference = (x - y); 1046 return (difference > 0); 1047 } 1048 1049 static inline int tid_geq(tid_t x, tid_t y) 1050 { 1051 int difference = (x - y); 1052 return (difference >= 0); 1053 } 1054 1055 extern int journal_blocks_per_page(struct inode *inode); 1056 1057 /* 1058 * Return the minimum number of blocks which must be free in the journal 1059 * before a new transaction may be started. Must be called under j_state_lock. 1060 */ 1061 static inline int jbd_space_needed(journal_t *journal) 1062 { 1063 int nblocks = journal->j_max_transaction_buffers; 1064 if (journal->j_committing_transaction) 1065 nblocks += journal->j_committing_transaction-> 1066 t_outstanding_credits; 1067 return nblocks; 1068 } 1069 1070 /* 1071 * Definitions which augment the buffer_head layer 1072 */ 1073 1074 /* journaling buffer types */ 1075 #define BJ_None 0 /* Not journaled */ 1076 #define BJ_SyncData 1 /* Normal data: flush before commit */ 1077 #define BJ_Metadata 2 /* Normal journaled metadata */ 1078 #define BJ_Forget 3 /* Buffer superseded by this transaction */ 1079 #define BJ_IO 4 /* Buffer is for temporary IO use */ 1080 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1081 #define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1082 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1083 #define BJ_Locked 8 /* Locked for I/O during commit */ 1084 #define BJ_Types 9 1085 1086 extern int jbd_blocks_per_page(struct inode *inode); 1087 1088 #ifdef __KERNEL__ 1089 1090 #define buffer_trace_init(bh) do {} while (0) 1091 #define print_buffer_fields(bh) do {} while (0) 1092 #define print_buffer_trace(bh) do {} while (0) 1093 #define BUFFER_TRACE(bh, info) do {} while (0) 1094 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1095 #define JBUFFER_TRACE(jh, info) do {} while (0) 1096 1097 #endif /* __KERNEL__ */ 1098 1099 #endif /* _LINUX_JBD_H */ 1100
