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_JBD2_H 17 #define _LINUX_JBD2_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 JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 41 * certain classes of error which can occur due to failed IOs. Under 42 * normal use we want ext4 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 JBD2_PARANOID_IOFAIL 47 48 /* 49 * The default maximum commit age, in seconds. 50 */ 51 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 52 53 #ifdef CONFIG_JBD2_DEBUG 54 /* 55 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 56 * consistency checks. By default we don't do this unless 57 * CONFIG_JBD2_DEBUG is on. 58 */ 59 #define JBD2_EXPENSIVE_CHECKING 60 extern u8 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 74 static inline void *jbd2_alloc(size_t size, gfp_t flags) 75 { 76 return (void *)__get_free_pages(flags, get_order(size)); 77 } 78 79 static inline void jbd2_free(void *ptr, size_t size) 80 { 81 free_pages((unsigned long)ptr, get_order(size)); 82 }; 83 84 #define JBD2_MIN_JOURNAL_BLOCKS 1024 85 86 #ifdef __KERNEL__ 87 88 /** 89 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 90 * 91 * All filesystem modifications made by the process go 92 * through this handle. Recursive operations (such as quota operations) 93 * are gathered into a single update. 94 * 95 * The buffer credits field is used to account for journaled buffers 96 * being modified by the running process. To ensure that there is 97 * enough log space for all outstanding operations, we need to limit the 98 * number of outstanding buffers possible at any time. When the 99 * operation completes, any buffer credits not used are credited back to 100 * the transaction, so that at all times we know how many buffers the 101 * outstanding updates on a transaction might possibly touch. 102 * 103 * This is an opaque datatype. 104 **/ 105 typedef struct handle_s handle_t; /* Atomic operation type */ 106 107 108 /** 109 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 110 * 111 * journal_t is linked to from the fs superblock structure. 112 * 113 * We use the journal_t to keep track of all outstanding transaction 114 * activity on the filesystem, and to manage the state of the log 115 * writing process. 116 * 117 * This is an opaque datatype. 118 **/ 119 typedef struct journal_s journal_t; /* Journal control structure */ 120 #endif 121 122 /* 123 * Internal structures used by the logging mechanism: 124 */ 125 126 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 127 128 /* 129 * On-disk structures 130 */ 131 132 /* 133 * Descriptor block types: 134 */ 135 136 #define JBD2_DESCRIPTOR_BLOCK 1 137 #define JBD2_COMMIT_BLOCK 2 138 #define JBD2_SUPERBLOCK_V1 3 139 #define JBD2_SUPERBLOCK_V2 4 140 #define JBD2_REVOKE_BLOCK 5 141 142 /* 143 * Standard header for all descriptor blocks: 144 */ 145 typedef struct journal_header_s 146 { 147 __be32 h_magic; 148 __be32 h_blocktype; 149 __be32 h_sequence; 150 } journal_header_t; 151 152 153 /* 154 * The block tag: used to describe a single buffer in the journal. 155 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 156 * raw struct shouldn't be used for pointer math or sizeof() - use 157 * journal_tag_bytes(journal) instead to compute this. 158 */ 159 typedef struct journal_block_tag_s 160 { 161 __be32 t_blocknr; /* The on-disk block number */ 162 __be32 t_flags; /* See below */ 163 __be32 t_blocknr_high; /* most-significant high 32bits. */ 164 } journal_block_tag_t; 165 166 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 167 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 168 169 /* 170 * The revoke descriptor: used on disk to describe a series of blocks to 171 * be revoked from the log 172 */ 173 typedef struct jbd2_journal_revoke_header_s 174 { 175 journal_header_t r_header; 176 __be32 r_count; /* Count of bytes used in the block */ 177 } jbd2_journal_revoke_header_t; 178 179 180 /* Definitions for the journal tag flags word: */ 181 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 182 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 183 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 184 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 185 186 187 /* 188 * The journal superblock. All fields are in big-endian byte order. 189 */ 190 typedef struct journal_superblock_s 191 { 192 /* 0x0000 */ 193 journal_header_t s_header; 194 195 /* 0x000C */ 196 /* Static information describing the journal */ 197 __be32 s_blocksize; /* journal device blocksize */ 198 __be32 s_maxlen; /* total blocks in journal file */ 199 __be32 s_first; /* first block of log information */ 200 201 /* 0x0018 */ 202 /* Dynamic information describing the current state of the log */ 203 __be32 s_sequence; /* first commit ID expected in log */ 204 __be32 s_start; /* blocknr of start of log */ 205 206 /* 0x0020 */ 207 /* Error value, as set by jbd2_journal_abort(). */ 208 __be32 s_errno; 209 210 /* 0x0024 */ 211 /* Remaining fields are only valid in a version-2 superblock */ 212 __be32 s_feature_compat; /* compatible feature set */ 213 __be32 s_feature_incompat; /* incompatible feature set */ 214 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 215 /* 0x0030 */ 216 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 217 218 /* 0x0040 */ 219 __be32 s_nr_users; /* Nr of filesystems sharing log */ 220 221 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 222 223 /* 0x0048 */ 224 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 225 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 226 227 /* 0x0050 */ 228 __u32 s_padding[44]; 229 230 /* 0x0100 */ 231 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 232 /* 0x0400 */ 233 } journal_superblock_t; 234 235 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 236 ((j)->j_format_version >= 2 && \ 237 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 238 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 239 ((j)->j_format_version >= 2 && \ 240 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 241 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 242 ((j)->j_format_version >= 2 && \ 243 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 244 245 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 246 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 247 248 /* Features known to this kernel version: */ 249 #define JBD2_KNOWN_COMPAT_FEATURES 0 250 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 251 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 252 JBD2_FEATURE_INCOMPAT_64BIT) 253 254 #ifdef __KERNEL__ 255 256 #include <linux/fs.h> 257 #include <linux/sched.h> 258 259 #define JBD2_ASSERTIONS 260 #ifdef JBD2_ASSERTIONS 261 #define J_ASSERT(assert) \ 262 do { \ 263 if (!(assert)) { \ 264 printk (KERN_EMERG \ 265 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 266 __FUNCTION__, __FILE__, __LINE__, # assert); \ 267 BUG(); \ 268 } \ 269 } while (0) 270 271 #if defined(CONFIG_BUFFER_DEBUG) 272 void buffer_assertion_failure(struct buffer_head *bh); 273 #define J_ASSERT_BH(bh, expr) \ 274 do { \ 275 if (!(expr)) \ 276 buffer_assertion_failure(bh); \ 277 J_ASSERT(expr); \ 278 } while (0) 279 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 280 #else 281 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 282 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 283 #endif 284 285 #else 286 #define J_ASSERT(assert) do { } while (0) 287 #endif /* JBD2_ASSERTIONS */ 288 289 #if defined(JBD2_PARANOID_IOFAIL) 290 #define J_EXPECT(expr, why...) J_ASSERT(expr) 291 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 292 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 293 #else 294 #define __journal_expect(expr, why...) \ 295 ({ \ 296 int val = (expr); \ 297 if (!val) { \ 298 printk(KERN_ERR \ 299 "EXT3-fs unexpected failure: %s;\n",# expr); \ 300 printk(KERN_ERR why "\n"); \ 301 } \ 302 val; \ 303 }) 304 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 305 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 306 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 307 #endif 308 309 enum jbd_state_bits { 310 BH_JBD /* Has an attached ext3 journal_head */ 311 = BH_PrivateStart, 312 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 313 BH_Freed, /* Has been freed (truncated) */ 314 BH_Revoked, /* Has been revoked from the log */ 315 BH_RevokeValid, /* Revoked flag is valid */ 316 BH_JBDDirty, /* Is dirty but journaled */ 317 BH_State, /* Pins most journal_head state */ 318 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 319 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 320 }; 321 322 BUFFER_FNS(JBD, jbd) 323 BUFFER_FNS(JWrite, jwrite) 324 BUFFER_FNS(JBDDirty, jbddirty) 325 TAS_BUFFER_FNS(JBDDirty, jbddirty) 326 BUFFER_FNS(Revoked, revoked) 327 TAS_BUFFER_FNS(Revoked, revoked) 328 BUFFER_FNS(RevokeValid, revokevalid) 329 TAS_BUFFER_FNS(RevokeValid, revokevalid) 330 BUFFER_FNS(Freed, freed) 331 332 static inline struct buffer_head *jh2bh(struct journal_head *jh) 333 { 334 return jh->b_bh; 335 } 336 337 static inline struct journal_head *bh2jh(struct buffer_head *bh) 338 { 339 return bh->b_private; 340 } 341 342 static inline void jbd_lock_bh_state(struct buffer_head *bh) 343 { 344 bit_spin_lock(BH_State, &bh->b_state); 345 } 346 347 static inline int jbd_trylock_bh_state(struct buffer_head *bh) 348 { 349 return bit_spin_trylock(BH_State, &bh->b_state); 350 } 351 352 static inline int jbd_is_locked_bh_state(struct buffer_head *bh) 353 { 354 return bit_spin_is_locked(BH_State, &bh->b_state); 355 } 356 357 static inline void jbd_unlock_bh_state(struct buffer_head *bh) 358 { 359 bit_spin_unlock(BH_State, &bh->b_state); 360 } 361 362 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 363 { 364 bit_spin_lock(BH_JournalHead, &bh->b_state); 365 } 366 367 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 368 { 369 bit_spin_unlock(BH_JournalHead, &bh->b_state); 370 } 371 372 struct jbd2_revoke_table_s; 373 374 /** 375 * struct handle_s - The handle_s type is the concrete type associated with 376 * handle_t. 377 * @h_transaction: Which compound transaction is this update a part of? 378 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 379 * @h_ref: Reference count on this handle 380 * @h_err: Field for caller's use to track errors through large fs operations 381 * @h_sync: flag for sync-on-close 382 * @h_jdata: flag to force data journaling 383 * @h_aborted: flag indicating fatal error on handle 384 **/ 385 386 /* Docbook can't yet cope with the bit fields, but will leave the documentation 387 * in so it can be fixed later. 388 */ 389 390 struct handle_s 391 { 392 /* Which compound transaction is this update a part of? */ 393 transaction_t *h_transaction; 394 395 /* Number of remaining buffers we are allowed to dirty: */ 396 int h_buffer_credits; 397 398 /* Reference count on this handle */ 399 int h_ref; 400 401 /* Field for caller's use to track errors through large fs */ 402 /* operations */ 403 int h_err; 404 405 /* Flags [no locking] */ 406 unsigned int h_sync: 1; /* sync-on-close */ 407 unsigned int h_jdata: 1; /* force data journaling */ 408 unsigned int h_aborted: 1; /* fatal error on handle */ 409 }; 410 411 412 /* The transaction_t type is the guts of the journaling mechanism. It 413 * tracks a compound transaction through its various states: 414 * 415 * RUNNING: accepting new updates 416 * LOCKED: Updates still running but we don't accept new ones 417 * RUNDOWN: Updates are tidying up but have finished requesting 418 * new buffers to modify (state not used for now) 419 * FLUSH: All updates complete, but we are still writing to disk 420 * COMMIT: All data on disk, writing commit record 421 * FINISHED: We still have to keep the transaction for checkpointing. 422 * 423 * The transaction keeps track of all of the buffers modified by a 424 * running transaction, and all of the buffers committed but not yet 425 * flushed to home for finished transactions. 426 */ 427 428 /* 429 * Lock ranking: 430 * 431 * j_list_lock 432 * ->jbd_lock_bh_journal_head() (This is "innermost") 433 * 434 * j_state_lock 435 * ->jbd_lock_bh_state() 436 * 437 * jbd_lock_bh_state() 438 * ->j_list_lock 439 * 440 * j_state_lock 441 * ->t_handle_lock 442 * 443 * j_state_lock 444 * ->j_list_lock (journal_unmap_buffer) 445 * 446 */ 447 448 struct transaction_s 449 { 450 /* Pointer to the journal for this transaction. [no locking] */ 451 journal_t *t_journal; 452 453 /* Sequence number for this transaction [no locking] */ 454 tid_t t_tid; 455 456 /* 457 * Transaction's current state 458 * [no locking - only kjournald2 alters this] 459 * FIXME: needs barriers 460 * KLUDGE: [use j_state_lock] 461 */ 462 enum { 463 T_RUNNING, 464 T_LOCKED, 465 T_RUNDOWN, 466 T_FLUSH, 467 T_COMMIT, 468 T_FINISHED 469 } t_state; 470 471 /* 472 * Where in the log does this transaction's commit start? [no locking] 473 */ 474 unsigned long t_log_start; 475 476 /* Number of buffers on the t_buffers list [j_list_lock] */ 477 int t_nr_buffers; 478 479 /* 480 * Doubly-linked circular list of all buffers reserved but not yet 481 * modified by this transaction [j_list_lock] 482 */ 483 struct journal_head *t_reserved_list; 484 485 /* 486 * Doubly-linked circular list of all buffers under writeout during 487 * commit [j_list_lock] 488 */ 489 struct journal_head *t_locked_list; 490 491 /* 492 * Doubly-linked circular list of all metadata buffers owned by this 493 * transaction [j_list_lock] 494 */ 495 struct journal_head *t_buffers; 496 497 /* 498 * Doubly-linked circular list of all data buffers still to be 499 * flushed before this transaction can be committed [j_list_lock] 500 */ 501 struct journal_head *t_sync_datalist; 502 503 /* 504 * Doubly-linked circular list of all forget buffers (superseded 505 * buffers which we can un-checkpoint once this transaction commits) 506 * [j_list_lock] 507 */ 508 struct journal_head *t_forget; 509 510 /* 511 * Doubly-linked circular list of all buffers still to be flushed before 512 * this transaction can be checkpointed. [j_list_lock] 513 */ 514 struct journal_head *t_checkpoint_list; 515 516 /* 517 * Doubly-linked circular list of all buffers submitted for IO while 518 * checkpointing. [j_list_lock] 519 */ 520 struct journal_head *t_checkpoint_io_list; 521 522 /* 523 * Doubly-linked circular list of temporary buffers currently undergoing 524 * IO in the log [j_list_lock] 525 */ 526 struct journal_head *t_iobuf_list; 527 528 /* 529 * Doubly-linked circular list of metadata buffers being shadowed by log 530 * IO. The IO buffers on the iobuf list and the shadow buffers on this 531 * list match each other one for one at all times. [j_list_lock] 532 */ 533 struct journal_head *t_shadow_list; 534 535 /* 536 * Doubly-linked circular list of control buffers being written to the 537 * log. [j_list_lock] 538 */ 539 struct journal_head *t_log_list; 540 541 /* 542 * Protects info related to handles 543 */ 544 spinlock_t t_handle_lock; 545 546 /* 547 * Number of outstanding updates running on this transaction 548 * [t_handle_lock] 549 */ 550 int t_updates; 551 552 /* 553 * Number of buffers reserved for use by all handles in this transaction 554 * handle but not yet modified. [t_handle_lock] 555 */ 556 int t_outstanding_credits; 557 558 /* 559 * Forward and backward links for the circular list of all transactions 560 * awaiting checkpoint. [j_list_lock] 561 */ 562 transaction_t *t_cpnext, *t_cpprev; 563 564 /* 565 * When will the transaction expire (become due for commit), in jiffies? 566 * [no locking] 567 */ 568 unsigned long t_expires; 569 570 /* 571 * How many handles used this transaction? [t_handle_lock] 572 */ 573 int t_handle_count; 574 575 }; 576 577 /** 578 * struct journal_s - The journal_s type is the concrete type associated with 579 * journal_t. 580 * @j_flags: General journaling state flags 581 * @j_errno: Is there an outstanding uncleared error on the journal (from a 582 * prior abort)? 583 * @j_sb_buffer: First part of superblock buffer 584 * @j_superblock: Second part of superblock buffer 585 * @j_format_version: Version of the superblock format 586 * @j_state_lock: Protect the various scalars in the journal 587 * @j_barrier_count: Number of processes waiting to create a barrier lock 588 * @j_barrier: The barrier lock itself 589 * @j_running_transaction: The current running transaction.. 590 * @j_committing_transaction: the transaction we are pushing to disk 591 * @j_checkpoint_transactions: a linked circular list of all transactions 592 * waiting for checkpointing 593 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 594 * to start committing, or for a barrier lock to be released 595 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 596 * @j_wait_done_commit: Wait queue for waiting for commit to complete 597 * @j_wait_checkpoint: Wait queue to trigger checkpointing 598 * @j_wait_commit: Wait queue to trigger commit 599 * @j_wait_updates: Wait queue to wait for updates to complete 600 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 601 * @j_head: Journal head - identifies the first unused block in the journal 602 * @j_tail: Journal tail - identifies the oldest still-used block in the 603 * journal. 604 * @j_free: Journal free - how many free blocks are there in the journal? 605 * @j_first: The block number of the first usable block 606 * @j_last: The block number one beyond the last usable block 607 * @j_dev: Device where we store the journal 608 * @j_blocksize: blocksize for the location where we store the journal. 609 * @j_blk_offset: starting block offset for into the device where we store the 610 * journal 611 * @j_fs_dev: Device which holds the client fs. For internal journal this will 612 * be equal to j_dev 613 * @j_maxlen: Total maximum capacity of the journal region on disk. 614 * @j_list_lock: Protects the buffer lists and internal buffer state. 615 * @j_inode: Optional inode where we store the journal. If present, all journal 616 * block numbers are mapped into this inode via bmap(). 617 * @j_tail_sequence: Sequence number of the oldest transaction in the log 618 * @j_transaction_sequence: Sequence number of the next transaction to grant 619 * @j_commit_sequence: Sequence number of the most recently committed 620 * transaction 621 * @j_commit_request: Sequence number of the most recent transaction wanting 622 * commit 623 * @j_uuid: Uuid of client object. 624 * @j_task: Pointer to the current commit thread for this journal 625 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 626 * single compound commit transaction 627 * @j_commit_interval: What is the maximum transaction lifetime before we begin 628 * a commit? 629 * @j_commit_timer: The timer used to wakeup the commit thread 630 * @j_revoke_lock: Protect the revoke table 631 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 632 * current transaction. 633 * @j_revoke_table: alternate revoke tables for j_revoke 634 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 635 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 636 * number that will fit in j_blocksize 637 * @j_last_sync_writer: most recent pid which did a synchronous write 638 * @j_private: An opaque pointer to fs-private information. 639 */ 640 641 struct journal_s 642 { 643 /* General journaling state flags [j_state_lock] */ 644 unsigned long j_flags; 645 646 /* 647 * Is there an outstanding uncleared error on the journal (from a prior 648 * abort)? [j_state_lock] 649 */ 650 int j_errno; 651 652 /* The superblock buffer */ 653 struct buffer_head *j_sb_buffer; 654 journal_superblock_t *j_superblock; 655 656 /* Version of the superblock format */ 657 int j_format_version; 658 659 /* 660 * Protect the various scalars in the journal 661 */ 662 spinlock_t j_state_lock; 663 664 /* 665 * Number of processes waiting to create a barrier lock [j_state_lock] 666 */ 667 int j_barrier_count; 668 669 /* The barrier lock itself */ 670 struct mutex j_barrier; 671 672 /* 673 * Transactions: The current running transaction... 674 * [j_state_lock] [caller holding open handle] 675 */ 676 transaction_t *j_running_transaction; 677 678 /* 679 * the transaction we are pushing to disk 680 * [j_state_lock] [caller holding open handle] 681 */ 682 transaction_t *j_committing_transaction; 683 684 /* 685 * ... and a linked circular list of all transactions waiting for 686 * checkpointing. [j_list_lock] 687 */ 688 transaction_t *j_checkpoint_transactions; 689 690 /* 691 * Wait queue for waiting for a locked transaction to start committing, 692 * or for a barrier lock to be released 693 */ 694 wait_queue_head_t j_wait_transaction_locked; 695 696 /* Wait queue for waiting for checkpointing to complete */ 697 wait_queue_head_t j_wait_logspace; 698 699 /* Wait queue for waiting for commit to complete */ 700 wait_queue_head_t j_wait_done_commit; 701 702 /* Wait queue to trigger checkpointing */ 703 wait_queue_head_t j_wait_checkpoint; 704 705 /* Wait queue to trigger commit */ 706 wait_queue_head_t j_wait_commit; 707 708 /* Wait queue to wait for updates to complete */ 709 wait_queue_head_t j_wait_updates; 710 711 /* Semaphore for locking against concurrent checkpoints */ 712 struct mutex j_checkpoint_mutex; 713 714 /* 715 * Journal head: identifies the first unused block in the journal. 716 * [j_state_lock] 717 */ 718 unsigned long j_head; 719 720 /* 721 * Journal tail: identifies the oldest still-used block in the journal. 722 * [j_state_lock] 723 */ 724 unsigned long j_tail; 725 726 /* 727 * Journal free: how many free blocks are there in the journal? 728 * [j_state_lock] 729 */ 730 unsigned long j_free; 731 732 /* 733 * Journal start and end: the block numbers of the first usable block 734 * and one beyond the last usable block in the journal. [j_state_lock] 735 */ 736 unsigned long j_first; 737 unsigned long j_last; 738 739 /* 740 * Device, blocksize and starting block offset for the location where we 741 * store the journal. 742 */ 743 struct block_device *j_dev; 744 int j_blocksize; 745 unsigned long long j_blk_offset; 746 747 /* 748 * Device which holds the client fs. For internal journal this will be 749 * equal to j_dev. 750 */ 751 struct block_device *j_fs_dev; 752 753 /* Total maximum capacity of the journal region on disk. */ 754 unsigned int j_maxlen; 755 756 /* 757 * Protects the buffer lists and internal buffer state. 758 */ 759 spinlock_t j_list_lock; 760 761 /* Optional inode where we store the journal. If present, all */ 762 /* journal block numbers are mapped into this inode via */ 763 /* bmap(). */ 764 struct inode *j_inode; 765 766 /* 767 * Sequence number of the oldest transaction in the log [j_state_lock] 768 */ 769 tid_t j_tail_sequence; 770 771 /* 772 * Sequence number of the next transaction to grant [j_state_lock] 773 */ 774 tid_t j_transaction_sequence; 775 776 /* 777 * Sequence number of the most recently committed transaction 778 * [j_state_lock]. 779 */ 780 tid_t j_commit_sequence; 781 782 /* 783 * Sequence number of the most recent transaction wanting commit 784 * [j_state_lock] 785 */ 786 tid_t j_commit_request; 787 788 /* 789 * Journal uuid: identifies the object (filesystem, LVM volume etc) 790 * backed by this journal. This will eventually be replaced by an array 791 * of uuids, allowing us to index multiple devices within a single 792 * journal and to perform atomic updates across them. 793 */ 794 __u8 j_uuid[16]; 795 796 /* Pointer to the current commit thread for this journal */ 797 struct task_struct *j_task; 798 799 /* 800 * Maximum number of metadata buffers to allow in a single compound 801 * commit transaction 802 */ 803 int j_max_transaction_buffers; 804 805 /* 806 * What is the maximum transaction lifetime before we begin a commit? 807 */ 808 unsigned long j_commit_interval; 809 810 /* The timer used to wakeup the commit thread: */ 811 struct timer_list j_commit_timer; 812 813 /* 814 * The revoke table: maintains the list of revoked blocks in the 815 * current transaction. [j_revoke_lock] 816 */ 817 spinlock_t j_revoke_lock; 818 struct jbd2_revoke_table_s *j_revoke; 819 struct jbd2_revoke_table_s *j_revoke_table[2]; 820 821 /* 822 * array of bhs for jbd2_journal_commit_transaction 823 */ 824 struct buffer_head **j_wbuf; 825 int j_wbufsize; 826 827 pid_t j_last_sync_writer; 828 829 /* 830 * An opaque pointer to fs-private information. ext3 puts its 831 * superblock pointer here 832 */ 833 void *j_private; 834 }; 835 836 /* 837 * Journal flag definitions 838 */ 839 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 840 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 841 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 842 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 843 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 844 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 845 846 /* 847 * Function declarations for the journaling transaction and buffer 848 * management 849 */ 850 851 /* Filing buffers */ 852 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 853 extern void __jbd2_journal_unfile_buffer(struct journal_head *); 854 extern void __jbd2_journal_refile_buffer(struct journal_head *); 855 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 856 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 857 extern void __journal_free_buffer(struct journal_head *bh); 858 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 859 extern void __journal_clean_data_list(transaction_t *transaction); 860 861 /* Log buffer allocation */ 862 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 863 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 864 865 /* Commit management */ 866 extern void jbd2_journal_commit_transaction(journal_t *); 867 868 /* Checkpoint list management */ 869 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 870 int __jbd2_journal_remove_checkpoint(struct journal_head *); 871 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 872 873 /* Buffer IO */ 874 extern int 875 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 876 struct journal_head *jh_in, 877 struct journal_head **jh_out, 878 unsigned long long blocknr); 879 880 /* Transaction locking */ 881 extern void __wait_on_journal (journal_t *); 882 883 /* 884 * Journal locking. 885 * 886 * We need to lock the journal during transaction state changes so that nobody 887 * ever tries to take a handle on the running transaction while we are in the 888 * middle of moving it to the commit phase. j_state_lock does this. 889 * 890 * Note that the locking is completely interrupt unsafe. We never touch 891 * journal structures from interrupts. 892 */ 893 894 static inline handle_t *journal_current_handle(void) 895 { 896 return current->journal_info; 897 } 898 899 /* The journaling code user interface: 900 * 901 * Create and destroy handles 902 * Register buffer modifications against the current transaction. 903 */ 904 905 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 906 extern int jbd2_journal_restart (handle_t *, int nblocks); 907 extern int jbd2_journal_extend (handle_t *, int nblocks); 908 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 909 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 910 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 911 extern int jbd2_journal_dirty_data (handle_t *, struct buffer_head *); 912 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 913 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 914 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 915 extern void journal_sync_buffer (struct buffer_head *); 916 extern void jbd2_journal_invalidatepage(journal_t *, 917 struct page *, unsigned long); 918 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 919 extern int jbd2_journal_stop(handle_t *); 920 extern int jbd2_journal_flush (journal_t *); 921 extern void jbd2_journal_lock_updates (journal_t *); 922 extern void jbd2_journal_unlock_updates (journal_t *); 923 924 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 925 struct block_device *fs_dev, 926 unsigned long long start, int len, int bsize); 927 extern journal_t * jbd2_journal_init_inode (struct inode *); 928 extern int jbd2_journal_update_format (journal_t *); 929 extern int jbd2_journal_check_used_features 930 (journal_t *, unsigned long, unsigned long, unsigned long); 931 extern int jbd2_journal_check_available_features 932 (journal_t *, unsigned long, unsigned long, unsigned long); 933 extern int jbd2_journal_set_features 934 (journal_t *, unsigned long, unsigned long, unsigned long); 935 extern int jbd2_journal_create (journal_t *); 936 extern int jbd2_journal_load (journal_t *journal); 937 extern void jbd2_journal_destroy (journal_t *); 938 extern int jbd2_journal_recover (journal_t *journal); 939 extern int jbd2_journal_wipe (journal_t *, int); 940 extern int jbd2_journal_skip_recovery (journal_t *); 941 extern void jbd2_journal_update_superblock (journal_t *, int); 942 extern void __jbd2_journal_abort_hard (journal_t *); 943 extern void jbd2_journal_abort (journal_t *, int); 944 extern int jbd2_journal_errno (journal_t *); 945 extern void jbd2_journal_ack_err (journal_t *); 946 extern int jbd2_journal_clear_err (journal_t *); 947 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 948 extern int jbd2_journal_force_commit(journal_t *); 949 950 /* 951 * journal_head management 952 */ 953 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 954 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 955 void jbd2_journal_remove_journal_head(struct buffer_head *bh); 956 void jbd2_journal_put_journal_head(struct journal_head *jh); 957 958 /* 959 * handle management 960 */ 961 extern struct kmem_cache *jbd2_handle_cache; 962 963 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 964 { 965 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 966 } 967 968 static inline void jbd2_free_handle(handle_t *handle) 969 { 970 kmem_cache_free(jbd2_handle_cache, handle); 971 } 972 973 /* Primary revoke support */ 974 #define JOURNAL_REVOKE_DEFAULT_HASH 256 975 extern int jbd2_journal_init_revoke(journal_t *, int); 976 extern void jbd2_journal_destroy_revoke_caches(void); 977 extern int jbd2_journal_init_revoke_caches(void); 978 979 extern void jbd2_journal_destroy_revoke(journal_t *); 980 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 981 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 982 extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *); 983 984 /* Recovery revoke support */ 985 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 986 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 987 extern void jbd2_journal_clear_revoke(journal_t *); 988 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 989 990 /* 991 * The log thread user interface: 992 * 993 * Request space in the current transaction, and force transaction commit 994 * transitions on demand. 995 */ 996 997 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 998 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 999 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1000 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1001 int jbd2_journal_force_commit_nested(journal_t *journal); 1002 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1003 int jbd2_log_do_checkpoint(journal_t *journal); 1004 1005 void __jbd2_log_wait_for_space(journal_t *journal); 1006 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1007 extern int jbd2_cleanup_journal_tail(journal_t *); 1008 1009 /* Debugging code only: */ 1010 1011 #define jbd_ENOSYS() \ 1012 do { \ 1013 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \ 1014 current->state = TASK_UNINTERRUPTIBLE; \ 1015 schedule(); \ 1016 } while (1) 1017 1018 /* 1019 * is_journal_abort 1020 * 1021 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1022 * bit, when set, indicates that we have had a fatal error somewhere, 1023 * either inside the journaling layer or indicated to us by the client 1024 * (eg. ext3), and that we and should not commit any further 1025 * transactions. 1026 */ 1027 1028 static inline int is_journal_aborted(journal_t *journal) 1029 { 1030 return journal->j_flags & JBD2_ABORT; 1031 } 1032 1033 static inline int is_handle_aborted(handle_t *handle) 1034 { 1035 if (handle->h_aborted) 1036 return 1; 1037 return is_journal_aborted(handle->h_transaction->t_journal); 1038 } 1039 1040 static inline void jbd2_journal_abort_handle(handle_t *handle) 1041 { 1042 handle->h_aborted = 1; 1043 } 1044 1045 #endif /* __KERNEL__ */ 1046 1047 /* Comparison functions for transaction IDs: perform comparisons using 1048 * modulo arithmetic so that they work over sequence number wraps. */ 1049 1050 static inline int tid_gt(tid_t x, tid_t y) 1051 { 1052 int difference = (x - y); 1053 return (difference > 0); 1054 } 1055 1056 static inline int tid_geq(tid_t x, tid_t y) 1057 { 1058 int difference = (x - y); 1059 return (difference >= 0); 1060 } 1061 1062 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1063 extern size_t journal_tag_bytes(journal_t *journal); 1064 1065 /* 1066 * Return the minimum number of blocks which must be free in the journal 1067 * before a new transaction may be started. Must be called under j_state_lock. 1068 */ 1069 static inline int jbd_space_needed(journal_t *journal) 1070 { 1071 int nblocks = journal->j_max_transaction_buffers; 1072 if (journal->j_committing_transaction) 1073 nblocks += journal->j_committing_transaction-> 1074 t_outstanding_credits; 1075 return nblocks; 1076 } 1077 1078 /* 1079 * Definitions which augment the buffer_head layer 1080 */ 1081 1082 /* journaling buffer types */ 1083 #define BJ_None 0 /* Not journaled */ 1084 #define BJ_SyncData 1 /* Normal data: flush before commit */ 1085 #define BJ_Metadata 2 /* Normal journaled metadata */ 1086 #define BJ_Forget 3 /* Buffer superseded by this transaction */ 1087 #define BJ_IO 4 /* Buffer is for temporary IO use */ 1088 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1089 #define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1090 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1091 #define BJ_Locked 8 /* Locked for I/O during commit */ 1092 #define BJ_Types 9 1093 1094 extern int jbd_blocks_per_page(struct inode *inode); 1095 1096 #ifdef __KERNEL__ 1097 1098 #define buffer_trace_init(bh) do {} while (0) 1099 #define print_buffer_fields(bh) do {} while (0) 1100 #define print_buffer_trace(bh) do {} while (0) 1101 #define BUFFER_TRACE(bh, info) do {} while (0) 1102 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1103 #define JBUFFER_TRACE(jh, info) do {} while (0) 1104 1105 #endif /* __KERNEL__ */ 1106 1107 #endif /* _LINUX_JBD2_H */ 1108