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 60 extern 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 74 extern void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry); 75 extern void * jbd2_slab_alloc(size_t size, gfp_t flags); 76 extern 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 **/ 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 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 */ 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 * 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 */ 158 typedef 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 */ 172 typedef 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 */ 189 typedef 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) \ 261 do { \ 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) 271 void 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 307 308 enum 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 }; 320 321 BUFFER_FNS(JBD, jbd) 322 BUFFER_FNS(JWrite, jwrite) 323 BUFFER_FNS(JBDDirty, jbddirty) 324 TAS_BUFFER_FNS(JBDDirty, jbddirty) 325 BUFFER_FNS(Revoked, revoked) 326 TAS_BUFFER_FNS(Revoked, revoked) 327 BUFFER_FNS(RevokeValid, revokevalid) 328 TAS_BUFFER_FNS(RevokeValid, revokevalid) 329 BUFFER_FNS(Freed, freed) 330 331 static inline struct buffer_head *jh2bh(struct journal_head *jh) 332 { 333 return jh->b_bh; 334 } 335 336 static inline struct journal_head *bh2jh(struct buffer_head *bh) 337 { 338 return bh->b_private; 339 } 340 341 static inline void jbd_lock_bh_state(struct buffer_head *bh) 342 { 343 bit_spin_lock(BH_State, &bh->b_state); 344 } 345 346 static inline int jbd_trylock_bh_state(struct buffer_head *bh) 347 { 348 return bit_spin_trylock(BH_State, &bh->b_state); 349 } 350 351 static inline int jbd_is_locked_bh_state(struct buffer_head *bh) 352 { 353 return bit_spin_is_locked(BH_State, &bh->b_state); 354 } 355 356 static inline void jbd_unlock_bh_state(struct buffer_head *bh) 357 { 358 bit_spin_unlock(BH_State, &bh->b_state); 359 } 360 361 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 362 { 363 bit_spin_lock(BH_JournalHead, &bh->b_state); 364 } 365 366 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 367 { 368 bit_spin_unlock(BH_JournalHead, &bh->b_state); 369 } 370 371 struct 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 */ 388 389 struct 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 */ 446 447 struct 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 /* 456 * Transaction's current state 457 * [no locking - only kjournald2 alters this] 458 * FIXME: needs barriers 459 * KLUDGE: [use j_state_lock] 460 */ 461 enum { 462 T_RUNNING, 463 T_LOCKED, 464 T_RUNDOWN, 465 T_FLUSH, 466 T_COMMIT, 467 T_FINISHED 468 } t_state; 469 470 /* 471 * Where in the log does this transaction's commit start? [no locking] 472 */ 473 unsigned long t_log_start; 474 475 /* Number of buffers on the t_buffers list [j_list_lock] */ 476 int t_nr_buffers; 477 478 /* 479 * Doubly-linked circular list of all buffers reserved but not yet 480 * modified by this transaction [j_list_lock] 481 */ 482 struct journal_head *t_reserved_list; 483 484 /* 485 * Doubly-linked circular list of all buffers under writeout during 486 * commit [j_list_lock] 487 */ 488 struct journal_head *t_locked_list; 489 490 /* 491 * Doubly-linked circular list of all metadata buffers owned by this 492 * transaction [j_list_lock] 493 */ 494 struct journal_head *t_buffers; 495 496 /* 497 * Doubly-linked circular list of all data buffers still to be 498 * flushed before this transaction can be committed [j_list_lock] 499 */ 500 struct journal_head *t_sync_datalist; 501 502 /* 503 * Doubly-linked circular list of all forget buffers (superseded 504 * buffers which we can un-checkpoint once this transaction commits) 505 * [j_list_lock] 506 */ 507 struct journal_head *t_forget; 508 509 /* 510 * Doubly-linked circular list of all buffers still to be flushed before 511 * this transaction can be checkpointed. [j_list_lock] 512 */ 513 struct journal_head *t_checkpoint_list; 514 515 /* 516 * Doubly-linked circular list of all buffers submitted for IO while 517 * checkpointing. [j_list_lock] 518 */ 519 struct journal_head *t_checkpoint_io_list; 520 521 /* 522 * Doubly-linked circular list of temporary buffers currently undergoing 523 * IO in the log [j_list_lock] 524 */ 525 struct journal_head *t_iobuf_list; 526 527 /* 528 * Doubly-linked circular list of metadata buffers being shadowed by log 529 * IO. The IO buffers on the iobuf list and the shadow buffers on this 530 * list match each other one for one at all times. [j_list_lock] 531 */ 532 struct journal_head *t_shadow_list; 533 534 /* 535 * Doubly-linked circular list of control buffers being written to the 536 * log. [j_list_lock] 537 */ 538 struct journal_head *t_log_list; 539 540 /* 541 * Protects info related to handles 542 */ 543 spinlock_t t_handle_lock; 544 545 /* 546 * Number of outstanding updates running on this transaction 547 * [t_handle_lock] 548 */ 549 int t_updates; 550 551 /* 552 * Number of buffers reserved for use by all handles in this transaction 553 * handle but not yet modified. [t_handle_lock] 554 */ 555 int t_outstanding_credits; 556 557 /* 558 * Forward and backward links for the circular list of all transactions 559 * awaiting checkpoint. [j_list_lock] 560 */ 561 transaction_t *t_cpnext, *t_cpprev; 562 563 /* 564 * When will the transaction expire (become due for commit), in jiffies? 565 * [no locking] 566 */ 567 unsigned long t_expires; 568 569 /* 570 * How many handles used this transaction? [t_handle_lock] 571 */ 572 int t_handle_count; 573 574 }; 575 576 /** 577 * struct journal_s - The journal_s type is the concrete type associated with 578 * journal_t. 579 * @j_flags: General journaling state flags 580 * @j_errno: Is there an outstanding uncleared error on the journal (from a 581 * prior abort)? 582 * @j_sb_buffer: First part of superblock buffer 583 * @j_superblock: Second part of superblock buffer 584 * @j_format_version: Version of the superblock format 585 * @j_state_lock: Protect the various scalars in the journal 586 * @j_barrier_count: Number of processes waiting to create a barrier lock 587 * @j_barrier: The barrier lock itself 588 * @j_running_transaction: The current running transaction.. 589 * @j_committing_transaction: the transaction we are pushing to disk 590 * @j_checkpoint_transactions: a linked circular list of all transactions 591 * waiting for checkpointing 592 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 593 * to start committing, or for a barrier lock to be released 594 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 595 * @j_wait_done_commit: Wait queue for waiting for commit to complete 596 * @j_wait_checkpoint: Wait queue to trigger checkpointing 597 * @j_wait_commit: Wait queue to trigger commit 598 * @j_wait_updates: Wait queue to wait for updates to complete 599 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 600 * @j_head: Journal head - identifies the first unused block in the journal 601 * @j_tail: Journal tail - identifies the oldest still-used block in the 602 * journal. 603 * @j_free: Journal free - how many free blocks are there in the journal? 604 * @j_first: The block number of the first usable block 605 * @j_last: The block number one beyond the last usable block 606 * @j_dev: Device where we store the journal 607 * @j_blocksize: blocksize for the location where we store the journal. 608 * @j_blk_offset: starting block offset for into the device where we store the 609 * journal 610 * @j_fs_dev: Device which holds the client fs. For internal journal this will 611 * be equal to j_dev 612 * @j_maxlen: Total maximum capacity of the journal region on disk. 613 * @j_list_lock: Protects the buffer lists and internal buffer state. 614 * @j_inode: Optional inode where we store the journal. If present, all journal 615 * block numbers are mapped into this inode via bmap(). 616 * @j_tail_sequence: Sequence number of the oldest transaction in the log 617 * @j_transaction_sequence: Sequence number of the next transaction to grant 618 * @j_commit_sequence: Sequence number of the most recently committed 619 * transaction 620 * @j_commit_request: Sequence number of the most recent transaction wanting 621 * commit 622 * @j_uuid: Uuid of client object. 623 * @j_task: Pointer to the current commit thread for this journal 624 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 625 * single compound commit transaction 626 * @j_commit_interval: What is the maximum transaction lifetime before we begin 627 * a commit? 628 * @j_commit_timer: The timer used to wakeup the commit thread 629 * @j_revoke_lock: Protect the revoke table 630 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 631 * current transaction. 632 * @j_revoke_table: alternate revoke tables for j_revoke 633 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 634 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 635 * number that will fit in j_blocksize 636 * @j_last_sync_writer: most recent pid which did a synchronous write 637 * @j_private: An opaque pointer to fs-private information. 638 */ 639 640 struct journal_s 641 { 642 /* General journaling state flags [j_state_lock] */ 643 unsigned long j_flags; 644 645 /* 646 * Is there an outstanding uncleared error on the journal (from a prior 647 * abort)? [j_state_lock] 648 */ 649 int j_errno; 650 651 /* The superblock buffer */ 652 struct buffer_head *j_sb_buffer; 653 journal_superblock_t *j_superblock; 654 655 /* Version of the superblock format */ 656 int j_format_version; 657 658 /* 659 * Protect the various scalars in the journal 660 */ 661 spinlock_t j_state_lock; 662 663 /* 664 * Number of processes waiting to create a barrier lock [j_state_lock] 665 */ 666 int j_barrier_count; 667 668 /* The barrier lock itself */ 669 struct mutex j_barrier; 670 671 /* 672 * Transactions: The current running transaction... 673 * [j_state_lock] [caller holding open handle] 674 */ 675 transaction_t *j_running_transaction; 676 677 /* 678 * the transaction we are pushing to disk 679 * [j_state_lock] [caller holding open handle] 680 */ 681 transaction_t *j_committing_transaction; 682 683 /* 684 * ... and a linked circular list of all transactions waiting for 685 * checkpointing. [j_list_lock] 686 */ 687 transaction_t *j_checkpoint_transactions; 688 689 /* 690 * Wait queue for waiting for a locked transaction to start committing, 691 * or for a barrier lock to be released 692 */ 693 wait_queue_head_t j_wait_transaction_locked; 694 695 /* Wait queue for waiting for checkpointing to complete */ 696 wait_queue_head_t j_wait_logspace; 697 698 /* Wait queue for waiting for commit to complete */ 699 wait_queue_head_t j_wait_done_commit; 700 701 /* Wait queue to trigger checkpointing */ 702 wait_queue_head_t j_wait_checkpoint; 703 704 /* Wait queue to trigger commit */ 705 wait_queue_head_t j_wait_commit; 706 707 /* Wait queue to wait for updates to complete */ 708 wait_queue_head_t j_wait_updates; 709 710 /* Semaphore for locking against concurrent checkpoints */ 711 struct mutex j_checkpoint_mutex; 712 713 /* 714 * Journal head: identifies the first unused block in the journal. 715 * [j_state_lock] 716 */ 717 unsigned long j_head; 718 719 /* 720 * Journal tail: identifies the oldest still-used block in the journal. 721 * [j_state_lock] 722 */ 723 unsigned long j_tail; 724 725 /* 726 * Journal free: how many free blocks are there in the journal? 727 * [j_state_lock] 728 */ 729 unsigned long j_free; 730 731 /* 732 * Journal start and end: the block numbers of the first usable block 733 * and one beyond the last usable block in the journal. [j_state_lock] 734 */ 735 unsigned long j_first; 736 unsigned long j_last; 737 738 /* 739 * Device, blocksize and starting block offset for the location where we 740 * store the journal. 741 */ 742 struct block_device *j_dev; 743 int j_blocksize; 744 unsigned long long j_blk_offset; 745 746 /* 747 * Device which holds the client fs. For internal journal this will be 748 * equal to j_dev. 749 */ 750 struct block_device *j_fs_dev; 751 752 /* Total maximum capacity of the journal region on disk. */ 753 unsigned int j_maxlen; 754 755 /* 756 * Protects the buffer lists and internal buffer state. 757 */ 758 spinlock_t j_list_lock; 759 760 /* Optional inode where we store the journal. If present, all */ 761 /* journal block numbers are mapped into this inode via */ 762 /* bmap(). */ 763 struct inode *j_inode; 764 765 /* 766 * Sequence number of the oldest transaction in the log [j_state_lock] 767 */ 768 tid_t j_tail_sequence; 769 770 /* 771 * Sequence number of the next transaction to grant [j_state_lock] 772 */ 773 tid_t j_transaction_sequence; 774 775 /* 776 * Sequence number of the most recently committed transaction 777 * [j_state_lock]. 778 */ 779 tid_t j_commit_sequence; 780 781 /* 782 * Sequence number of the most recent transaction wanting commit 783 * [j_state_lock] 784 */ 785 tid_t j_commit_request; 786 787 /* 788 * Journal uuid: identifies the object (filesystem, LVM volume etc) 789 * backed by this journal. This will eventually be replaced by an array 790 * of uuids, allowing us to index multiple devices within a single 791 * journal and to perform atomic updates across them. 792 */ 793 __u8 j_uuid[16]; 794 795 /* Pointer to the current commit thread for this journal */ 796 struct task_struct *j_task; 797 798 /* 799 * Maximum number of metadata buffers to allow in a single compound 800 * commit transaction 801 */ 802 int j_max_transaction_buffers; 803 804 /* 805 * What is the maximum transaction lifetime before we begin a commit? 806 */ 807 unsigned long j_commit_interval; 808 809 /* The timer used to wakeup the commit thread: */ 810 struct timer_list j_commit_timer; 811 812 /* 813 * The revoke table: maintains the list of revoked blocks in the 814 * current transaction. [j_revoke_lock] 815 */ 816 spinlock_t j_revoke_lock; 817 struct jbd2_revoke_table_s *j_revoke; 818 struct jbd2_revoke_table_s *j_revoke_table[2]; 819 820 /* 821 * array of bhs for jbd2_journal_commit_transaction 822 */ 823 struct buffer_head **j_wbuf; 824 int j_wbufsize; 825 826 pid_t j_last_sync_writer; 827 828 /* 829 * An opaque pointer to fs-private information. ext3 puts its 830 * superblock pointer here 831 */ 832 void *j_private; 833 }; 834 835 /* 836 * Journal flag definitions 837 */ 838 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 839 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 840 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 841 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 842 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 843 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 844 845 /* 846 * Function declarations for the journaling transaction and buffer 847 * management 848 */ 849 850 /* Filing buffers */ 851 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 852 extern void __jbd2_journal_unfile_buffer(struct journal_head *); 853 extern void __jbd2_journal_refile_buffer(struct journal_head *); 854 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 855 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 856 extern void __journal_free_buffer(struct journal_head *bh); 857 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 858 extern void __journal_clean_data_list(transaction_t *transaction); 859 860 /* Log buffer allocation */ 861 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 862 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 863 864 /* Commit management */ 865 extern void jbd2_journal_commit_transaction(journal_t *); 866 867 /* Checkpoint list management */ 868 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 869 int __jbd2_journal_remove_checkpoint(struct journal_head *); 870 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 871 872 /* Buffer IO */ 873 extern int 874 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 875 struct journal_head *jh_in, 876 struct journal_head **jh_out, 877 unsigned long long blocknr); 878 879 /* Transaction locking */ 880 extern void __wait_on_journal (journal_t *); 881 882 /* 883 * Journal locking. 884 * 885 * We need to lock the journal during transaction state changes so that nobody 886 * ever tries to take a handle on the running transaction while we are in the 887 * middle of moving it to the commit phase. j_state_lock does this. 888 * 889 * Note that the locking is completely interrupt unsafe. We never touch 890 * journal structures from interrupts. 891 */ 892 893 static inline handle_t *journal_current_handle(void) 894 { 895 return current->journal_info; 896 } 897 898 /* The journaling code user interface: 899 * 900 * Create and destroy handles 901 * Register buffer modifications against the current transaction. 902 */ 903 904 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 905 extern int jbd2_journal_restart (handle_t *, int nblocks); 906 extern int jbd2_journal_extend (handle_t *, int nblocks); 907 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 908 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 909 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 910 extern int jbd2_journal_dirty_data (handle_t *, struct buffer_head *); 911 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 912 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 913 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 914 extern void journal_sync_buffer (struct buffer_head *); 915 extern void jbd2_journal_invalidatepage(journal_t *, 916 struct page *, unsigned long); 917 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 918 extern int jbd2_journal_stop(handle_t *); 919 extern int jbd2_journal_flush (journal_t *); 920 extern void jbd2_journal_lock_updates (journal_t *); 921 extern void jbd2_journal_unlock_updates (journal_t *); 922 923 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 924 struct block_device *fs_dev, 925 unsigned long long start, int len, int bsize); 926 extern journal_t * jbd2_journal_init_inode (struct inode *); 927 extern int jbd2_journal_update_format (journal_t *); 928 extern int jbd2_journal_check_used_features 929 (journal_t *, unsigned long, unsigned long, unsigned long); 930 extern int jbd2_journal_check_available_features 931 (journal_t *, unsigned long, unsigned long, unsigned long); 932 extern int jbd2_journal_set_features 933 (journal_t *, unsigned long, unsigned long, unsigned long); 934 extern int jbd2_journal_create (journal_t *); 935 extern int jbd2_journal_load (journal_t *journal); 936 extern void jbd2_journal_destroy (journal_t *); 937 extern int jbd2_journal_recover (journal_t *journal); 938 extern int jbd2_journal_wipe (journal_t *, int); 939 extern int jbd2_journal_skip_recovery (journal_t *); 940 extern void jbd2_journal_update_superblock (journal_t *, int); 941 extern void __jbd2_journal_abort_hard (journal_t *); 942 extern void jbd2_journal_abort (journal_t *, int); 943 extern int jbd2_journal_errno (journal_t *); 944 extern void jbd2_journal_ack_err (journal_t *); 945 extern int jbd2_journal_clear_err (journal_t *); 946 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 947 extern int jbd2_journal_force_commit(journal_t *); 948 949 /* 950 * journal_head management 951 */ 952 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 953 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 954 void jbd2_journal_remove_journal_head(struct buffer_head *bh); 955 void jbd2_journal_put_journal_head(struct journal_head *jh); 956 957 /* 958 * handle management 959 */ 960 extern struct kmem_cache *jbd2_handle_cache; 961 962 static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) 963 { 964 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 965 } 966 967 static inline void jbd_free_handle(handle_t *handle) 968 { 969 kmem_cache_free(jbd2_handle_cache, handle); 970 } 971 972 /* Primary revoke support */ 973 #define JOURNAL_REVOKE_DEFAULT_HASH 256 974 extern int jbd2_journal_init_revoke(journal_t *, int); 975 extern void jbd2_journal_destroy_revoke_caches(void); 976 extern int jbd2_journal_init_revoke_caches(void); 977 978 extern void jbd2_journal_destroy_revoke(journal_t *); 979 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 980 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 981 extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *); 982 983 /* Recovery revoke support */ 984 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 985 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 986 extern void jbd2_journal_clear_revoke(journal_t *); 987 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 988 989 /* 990 * The log thread user interface: 991 * 992 * Request space in the current transaction, and force transaction commit 993 * transitions on demand. 994 */ 995 996 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 997 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 998 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 999 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1000 int jbd2_journal_force_commit_nested(journal_t *journal); 1001 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1002 int jbd2_log_do_checkpoint(journal_t *journal); 1003 1004 void __jbd2_log_wait_for_space(journal_t *journal); 1005 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1006 extern int jbd2_cleanup_journal_tail(journal_t *); 1007 1008 /* Debugging code only: */ 1009 1010 #define jbd_ENOSYS() \ 1011 do { \ 1012 printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \ 1013 current->state = TASK_UNINTERRUPTIBLE; \ 1014 schedule(); \ 1015 } while (1) 1016 1017 /* 1018 * is_journal_abort 1019 * 1020 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1021 * bit, when set, indicates that we have had a fatal error somewhere, 1022 * either inside the journaling layer or indicated to us by the client 1023 * (eg. ext3), and that we and should not commit any further 1024 * transactions. 1025 */ 1026 1027 static inline int is_journal_aborted(journal_t *journal) 1028 { 1029 return journal->j_flags & JBD2_ABORT; 1030 } 1031 1032 static inline int is_handle_aborted(handle_t *handle) 1033 { 1034 if (handle->h_aborted) 1035 return 1; 1036 return is_journal_aborted(handle->h_transaction->t_journal); 1037 } 1038 1039 static inline void jbd2_journal_abort_handle(handle_t *handle) 1040 { 1041 handle->h_aborted = 1; 1042 } 1043 1044 #endif /* __KERNEL__ */ 1045 1046 /* Comparison functions for transaction IDs: perform comparisons using 1047 * modulo arithmetic so that they work over sequence number wraps. */ 1048 1049 static inline int tid_gt(tid_t x, tid_t y) 1050 { 1051 int difference = (x - y); 1052 return (difference > 0); 1053 } 1054 1055 static inline int tid_geq(tid_t x, tid_t y) 1056 { 1057 int difference = (x - y); 1058 return (difference >= 0); 1059 } 1060 1061 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1062 extern size_t journal_tag_bytes(journal_t *journal); 1063 1064 /* 1065 * Return the minimum number of blocks which must be free in the journal 1066 * before a new transaction may be started. Must be called under j_state_lock. 1067 */ 1068 static inline int jbd_space_needed(journal_t *journal) 1069 { 1070 int nblocks = journal->j_max_transaction_buffers; 1071 if (journal->j_committing_transaction) 1072 nblocks += journal->j_committing_transaction-> 1073 t_outstanding_credits; 1074 return nblocks; 1075 } 1076 1077 /* 1078 * Definitions which augment the buffer_head layer 1079 */ 1080 1081 /* journaling buffer types */ 1082 #define BJ_None 0 /* Not journaled */ 1083 #define BJ_SyncData 1 /* Normal data: flush before commit */ 1084 #define BJ_Metadata 2 /* Normal journaled metadata */ 1085 #define BJ_Forget 3 /* Buffer superseded by this transaction */ 1086 #define BJ_IO 4 /* Buffer is for temporary IO use */ 1087 #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ 1088 #define BJ_LogCtl 6 /* Buffer contains log descriptors */ 1089 #define BJ_Reserved 7 /* Buffer is reserved for access by journal */ 1090 #define BJ_Locked 8 /* Locked for I/O during commit */ 1091 #define BJ_Types 9 1092 1093 extern int jbd_blocks_per_page(struct inode *inode); 1094 1095 #ifdef __KERNEL__ 1096 1097 #define buffer_trace_init(bh) do {} while (0) 1098 #define print_buffer_fields(bh) do {} while (0) 1099 #define print_buffer_trace(bh) do {} while (0) 1100 #define BUFFER_TRACE(bh, info) do {} while (0) 1101 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1102 #define JBUFFER_TRACE(jh, info) do {} while (0) 1103 1104 #endif /* __KERNEL__ */ 1105 1106 #endif /* _LINUX_JBD_H */ 1107