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 #endif 34 35 #define journal_oom_retry 1 36 37 /* 38 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 39 * certain classes of error which can occur due to failed IOs. Under 40 * normal use we want ext4 to continue after such errors, because 41 * hardware _can_ fail, but for debugging purposes when running tests on 42 * known-good hardware we may want to trap these errors. 43 */ 44 #undef JBD2_PARANOID_IOFAIL 45 46 /* 47 * The default maximum commit age, in seconds. 48 */ 49 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 50 51 #ifdef CONFIG_JBD2_DEBUG 52 /* 53 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 54 * consistency checks. By default we don't do this unless 55 * CONFIG_JBD2_DEBUG is on. 56 */ 57 #define JBD2_EXPENSIVE_CHECKING 58 extern u8 jbd2_journal_enable_debug; 59 60 #define jbd_debug(n, f, a...) \ 61 do { \ 62 if ((n) <= jbd2_journal_enable_debug) { \ 63 printk (KERN_DEBUG "(%s, %d): %s: ", \ 64 __FILE__, __LINE__, __func__); \ 65 printk (f, ## a); \ 66 } \ 67 } while (0) 68 #else 69 #define jbd_debug(f, a...) /**/ 70 #endif 71 72 static inline void *jbd2_alloc(size_t size, gfp_t flags) 73 { 74 return (void *)__get_free_pages(flags, get_order(size)); 75 } 76 77 static inline void jbd2_free(void *ptr, size_t size) 78 { 79 free_pages((unsigned long)ptr, get_order(size)); 80 }; 81 82 #define JBD2_MIN_JOURNAL_BLOCKS 1024 83 84 #ifdef __KERNEL__ 85 86 /** 87 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 88 * 89 * All filesystem modifications made by the process go 90 * through this handle. Recursive operations (such as quota operations) 91 * are gathered into a single update. 92 * 93 * The buffer credits field is used to account for journaled buffers 94 * being modified by the running process. To ensure that there is 95 * enough log space for all outstanding operations, we need to limit the 96 * number of outstanding buffers possible at any time. When the 97 * operation completes, any buffer credits not used are credited back to 98 * the transaction, so that at all times we know how many buffers the 99 * outstanding updates on a transaction might possibly touch. 100 * 101 * This is an opaque datatype. 102 **/ 103 typedef struct handle_s handle_t; /* Atomic operation type */ 104 105 106 /** 107 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 108 * 109 * journal_t is linked to from the fs superblock structure. 110 * 111 * We use the journal_t to keep track of all outstanding transaction 112 * activity on the filesystem, and to manage the state of the log 113 * writing process. 114 * 115 * This is an opaque datatype. 116 **/ 117 typedef struct journal_s journal_t; /* Journal control structure */ 118 #endif 119 120 /* 121 * Internal structures used by the logging mechanism: 122 */ 123 124 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 125 126 /* 127 * On-disk structures 128 */ 129 130 /* 131 * Descriptor block types: 132 */ 133 134 #define JBD2_DESCRIPTOR_BLOCK 1 135 #define JBD2_COMMIT_BLOCK 2 136 #define JBD2_SUPERBLOCK_V1 3 137 #define JBD2_SUPERBLOCK_V2 4 138 #define JBD2_REVOKE_BLOCK 5 139 140 /* 141 * Standard header for all descriptor blocks: 142 */ 143 typedef struct journal_header_s 144 { 145 __be32 h_magic; 146 __be32 h_blocktype; 147 __be32 h_sequence; 148 } journal_header_t; 149 150 /* 151 * Checksum types. 152 */ 153 #define JBD2_CRC32_CHKSUM 1 154 #define JBD2_MD5_CHKSUM 2 155 #define JBD2_SHA1_CHKSUM 3 156 157 #define JBD2_CRC32_CHKSUM_SIZE 4 158 159 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 160 /* 161 * Commit block header for storing transactional checksums: 162 */ 163 struct commit_header { 164 __be32 h_magic; 165 __be32 h_blocktype; 166 __be32 h_sequence; 167 unsigned char h_chksum_type; 168 unsigned char h_chksum_size; 169 unsigned char h_padding[2]; 170 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 171 __be64 h_commit_sec; 172 __be32 h_commit_nsec; 173 }; 174 175 /* 176 * The block tag: used to describe a single buffer in the journal. 177 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 178 * raw struct shouldn't be used for pointer math or sizeof() - use 179 * journal_tag_bytes(journal) instead to compute this. 180 */ 181 typedef struct journal_block_tag_s 182 { 183 __be32 t_blocknr; /* The on-disk block number */ 184 __be32 t_flags; /* See below */ 185 __be32 t_blocknr_high; /* most-significant high 32bits. */ 186 } journal_block_tag_t; 187 188 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 189 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 190 191 /* 192 * The revoke descriptor: used on disk to describe a series of blocks to 193 * be revoked from the log 194 */ 195 typedef struct jbd2_journal_revoke_header_s 196 { 197 journal_header_t r_header; 198 __be32 r_count; /* Count of bytes used in the block */ 199 } jbd2_journal_revoke_header_t; 200 201 202 /* Definitions for the journal tag flags word: */ 203 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 204 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 205 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 206 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 207 208 209 /* 210 * The journal superblock. All fields are in big-endian byte order. 211 */ 212 typedef struct journal_superblock_s 213 { 214 /* 0x0000 */ 215 journal_header_t s_header; 216 217 /* 0x000C */ 218 /* Static information describing the journal */ 219 __be32 s_blocksize; /* journal device blocksize */ 220 __be32 s_maxlen; /* total blocks in journal file */ 221 __be32 s_first; /* first block of log information */ 222 223 /* 0x0018 */ 224 /* Dynamic information describing the current state of the log */ 225 __be32 s_sequence; /* first commit ID expected in log */ 226 __be32 s_start; /* blocknr of start of log */ 227 228 /* 0x0020 */ 229 /* Error value, as set by jbd2_journal_abort(). */ 230 __be32 s_errno; 231 232 /* 0x0024 */ 233 /* Remaining fields are only valid in a version-2 superblock */ 234 __be32 s_feature_compat; /* compatible feature set */ 235 __be32 s_feature_incompat; /* incompatible feature set */ 236 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 237 /* 0x0030 */ 238 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 239 240 /* 0x0040 */ 241 __be32 s_nr_users; /* Nr of filesystems sharing log */ 242 243 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 244 245 /* 0x0048 */ 246 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 247 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 248 249 /* 0x0050 */ 250 __u32 s_padding[44]; 251 252 /* 0x0100 */ 253 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 254 /* 0x0400 */ 255 } journal_superblock_t; 256 257 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 258 ((j)->j_format_version >= 2 && \ 259 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 260 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 261 ((j)->j_format_version >= 2 && \ 262 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 263 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 264 ((j)->j_format_version >= 2 && \ 265 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 266 267 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 268 269 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 270 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 271 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 272 273 /* Features known to this kernel version: */ 274 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 275 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 276 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 277 JBD2_FEATURE_INCOMPAT_64BIT | \ 278 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) 279 280 #ifdef __KERNEL__ 281 282 #include <linux/fs.h> 283 #include <linux/sched.h> 284 285 #define J_ASSERT(assert) BUG_ON(!(assert)) 286 287 #if defined(CONFIG_BUFFER_DEBUG) 288 void buffer_assertion_failure(struct buffer_head *bh); 289 #define J_ASSERT_BH(bh, expr) \ 290 do { \ 291 if (!(expr)) \ 292 buffer_assertion_failure(bh); \ 293 J_ASSERT(expr); \ 294 } while (0) 295 #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 296 #else 297 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 298 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 299 #endif 300 301 #if defined(JBD2_PARANOID_IOFAIL) 302 #define J_EXPECT(expr, why...) J_ASSERT(expr) 303 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 304 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 305 #else 306 #define __journal_expect(expr, why...) \ 307 ({ \ 308 int val = (expr); \ 309 if (!val) { \ 310 printk(KERN_ERR \ 311 "JBD2 unexpected failure: %s: %s;\n", \ 312 __func__, #expr); \ 313 printk(KERN_ERR why "\n"); \ 314 } \ 315 val; \ 316 }) 317 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 318 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 319 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 320 #endif 321 322 enum jbd_state_bits { 323 BH_JBD /* Has an attached ext3 journal_head */ 324 = BH_PrivateStart, 325 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 326 BH_Freed, /* Has been freed (truncated) */ 327 BH_Revoked, /* Has been revoked from the log */ 328 BH_RevokeValid, /* Revoked flag is valid */ 329 BH_JBDDirty, /* Is dirty but journaled */ 330 BH_State, /* Pins most journal_head state */ 331 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 332 BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ 333 BH_JBDPrivateStart, /* First bit available for private use by FS */ 334 }; 335 336 BUFFER_FNS(JBD, jbd) 337 BUFFER_FNS(JWrite, jwrite) 338 BUFFER_FNS(JBDDirty, jbddirty) 339 TAS_BUFFER_FNS(JBDDirty, jbddirty) 340 BUFFER_FNS(Revoked, revoked) 341 TAS_BUFFER_FNS(Revoked, revoked) 342 BUFFER_FNS(RevokeValid, revokevalid) 343 TAS_BUFFER_FNS(RevokeValid, revokevalid) 344 BUFFER_FNS(Freed, freed) 345 346 static inline struct buffer_head *jh2bh(struct journal_head *jh) 347 { 348 return jh->b_bh; 349 } 350 351 static inline struct journal_head *bh2jh(struct buffer_head *bh) 352 { 353 return bh->b_private; 354 } 355 356 static inline void jbd_lock_bh_state(struct buffer_head *bh) 357 { 358 bit_spin_lock(BH_State, &bh->b_state); 359 } 360 361 static inline int jbd_trylock_bh_state(struct buffer_head *bh) 362 { 363 return bit_spin_trylock(BH_State, &bh->b_state); 364 } 365 366 static inline int jbd_is_locked_bh_state(struct buffer_head *bh) 367 { 368 return bit_spin_is_locked(BH_State, &bh->b_state); 369 } 370 371 static inline void jbd_unlock_bh_state(struct buffer_head *bh) 372 { 373 bit_spin_unlock(BH_State, &bh->b_state); 374 } 375 376 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 377 { 378 bit_spin_lock(BH_JournalHead, &bh->b_state); 379 } 380 381 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 382 { 383 bit_spin_unlock(BH_JournalHead, &bh->b_state); 384 } 385 386 /* Flags in jbd_inode->i_flags */ 387 #define __JI_COMMIT_RUNNING 0 388 /* Commit of the inode data in progress. We use this flag to protect us from 389 * concurrent deletion of inode. We cannot use reference to inode for this 390 * since we cannot afford doing last iput() on behalf of kjournald 391 */ 392 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 393 394 /** 395 * struct jbd_inode is the structure linking inodes in ordered mode 396 * present in a transaction so that we can sync them during commit. 397 */ 398 struct jbd2_inode { 399 /* Which transaction does this inode belong to? Either the running 400 * transaction or the committing one. [j_list_lock] */ 401 transaction_t *i_transaction; 402 403 /* Pointer to the running transaction modifying inode's data in case 404 * there is already a committing transaction touching it. [j_list_lock] */ 405 transaction_t *i_next_transaction; 406 407 /* List of inodes in the i_transaction [j_list_lock] */ 408 struct list_head i_list; 409 410 /* VFS inode this inode belongs to [constant during the lifetime 411 * of the structure] */ 412 struct inode *i_vfs_inode; 413 414 /* Flags of inode [j_list_lock] */ 415 unsigned int i_flags; 416 }; 417 418 struct jbd2_revoke_table_s; 419 420 /** 421 * struct handle_s - The handle_s type is the concrete type associated with 422 * handle_t. 423 * @h_transaction: Which compound transaction is this update a part of? 424 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 425 * @h_ref: Reference count on this handle 426 * @h_err: Field for caller's use to track errors through large fs operations 427 * @h_sync: flag for sync-on-close 428 * @h_jdata: flag to force data journaling 429 * @h_aborted: flag indicating fatal error on handle 430 **/ 431 432 /* Docbook can't yet cope with the bit fields, but will leave the documentation 433 * in so it can be fixed later. 434 */ 435 436 struct handle_s 437 { 438 /* Which compound transaction is this update a part of? */ 439 transaction_t *h_transaction; 440 441 /* Number of remaining buffers we are allowed to dirty: */ 442 int h_buffer_credits; 443 444 /* Reference count on this handle */ 445 int h_ref; 446 447 /* Field for caller's use to track errors through large fs */ 448 /* operations */ 449 int h_err; 450 451 /* Flags [no locking] */ 452 unsigned int h_sync: 1; /* sync-on-close */ 453 unsigned int h_jdata: 1; /* force data journaling */ 454 unsigned int h_aborted: 1; /* fatal error on handle */ 455 456 #ifdef CONFIG_DEBUG_LOCK_ALLOC 457 struct lockdep_map h_lockdep_map; 458 #endif 459 }; 460 461 462 /* 463 * Some stats for checkpoint phase 464 */ 465 struct transaction_chp_stats_s { 466 unsigned long cs_chp_time; 467 __u32 cs_forced_to_close; 468 __u32 cs_written; 469 __u32 cs_dropped; 470 }; 471 472 /* The transaction_t type is the guts of the journaling mechanism. It 473 * tracks a compound transaction through its various states: 474 * 475 * RUNNING: accepting new updates 476 * LOCKED: Updates still running but we don't accept new ones 477 * RUNDOWN: Updates are tidying up but have finished requesting 478 * new buffers to modify (state not used for now) 479 * FLUSH: All updates complete, but we are still writing to disk 480 * COMMIT: All data on disk, writing commit record 481 * FINISHED: We still have to keep the transaction for checkpointing. 482 * 483 * The transaction keeps track of all of the buffers modified by a 484 * running transaction, and all of the buffers committed but not yet 485 * flushed to home for finished transactions. 486 */ 487 488 /* 489 * Lock ranking: 490 * 491 * j_list_lock 492 * ->jbd_lock_bh_journal_head() (This is "innermost") 493 * 494 * j_state_lock 495 * ->jbd_lock_bh_state() 496 * 497 * jbd_lock_bh_state() 498 * ->j_list_lock 499 * 500 * j_state_lock 501 * ->t_handle_lock 502 * 503 * j_state_lock 504 * ->j_list_lock (journal_unmap_buffer) 505 * 506 */ 507 508 struct transaction_s 509 { 510 /* Pointer to the journal for this transaction. [no locking] */ 511 journal_t *t_journal; 512 513 /* Sequence number for this transaction [no locking] */ 514 tid_t t_tid; 515 516 /* 517 * Transaction's current state 518 * [no locking - only kjournald2 alters this] 519 * [j_list_lock] guards transition of a transaction into T_FINISHED 520 * state and subsequent call of __jbd2_journal_drop_transaction() 521 * FIXME: needs barriers 522 * KLUDGE: [use j_state_lock] 523 */ 524 enum { 525 T_RUNNING, 526 T_LOCKED, 527 T_RUNDOWN, 528 T_FLUSH, 529 T_COMMIT, 530 T_FINISHED 531 } t_state; 532 533 /* 534 * Where in the log does this transaction's commit start? [no locking] 535 */ 536 unsigned long t_log_start; 537 538 /* Number of buffers on the t_buffers list [j_list_lock] */ 539 int t_nr_buffers; 540 541 /* 542 * Doubly-linked circular list of all buffers reserved but not yet 543 * modified by this transaction [j_list_lock] 544 */ 545 struct journal_head *t_reserved_list; 546 547 /* 548 * Doubly-linked circular list of all metadata buffers owned by this 549 * transaction [j_list_lock] 550 */ 551 struct journal_head *t_buffers; 552 553 /* 554 * Doubly-linked circular list of all forget buffers (superseded 555 * buffers which we can un-checkpoint once this transaction commits) 556 * [j_list_lock] 557 */ 558 struct journal_head *t_forget; 559 560 /* 561 * Doubly-linked circular list of all buffers still to be flushed before 562 * this transaction can be checkpointed. [j_list_lock] 563 */ 564 struct journal_head *t_checkpoint_list; 565 566 /* 567 * Doubly-linked circular list of all buffers submitted for IO while 568 * checkpointing. [j_list_lock] 569 */ 570 struct journal_head *t_checkpoint_io_list; 571 572 /* 573 * Doubly-linked circular list of temporary buffers currently undergoing 574 * IO in the log [j_list_lock] 575 */ 576 struct journal_head *t_iobuf_list; 577 578 /* 579 * Doubly-linked circular list of metadata buffers being shadowed by log 580 * IO. The IO buffers on the iobuf list and the shadow buffers on this 581 * list match each other one for one at all times. [j_list_lock] 582 */ 583 struct journal_head *t_shadow_list; 584 585 /* 586 * Doubly-linked circular list of control buffers being written to the 587 * log. [j_list_lock] 588 */ 589 struct journal_head *t_log_list; 590 591 /* 592 * List of inodes whose data we've modified in data=ordered mode. 593 * [j_list_lock] 594 */ 595 struct list_head t_inode_list; 596 597 /* 598 * Protects info related to handles 599 */ 600 spinlock_t t_handle_lock; 601 602 /* 603 * Longest time some handle had to wait for running transaction 604 */ 605 unsigned long t_max_wait; 606 607 /* 608 * When transaction started 609 */ 610 unsigned long t_start; 611 612 /* 613 * Checkpointing stats [j_checkpoint_sem] 614 */ 615 struct transaction_chp_stats_s t_chp_stats; 616 617 /* 618 * Number of outstanding updates running on this transaction 619 * [t_handle_lock] 620 */ 621 int t_updates; 622 623 /* 624 * Number of buffers reserved for use by all handles in this transaction 625 * handle but not yet modified. [t_handle_lock] 626 */ 627 int t_outstanding_credits; 628 629 /* 630 * Forward and backward links for the circular list of all transactions 631 * awaiting checkpoint. [j_list_lock] 632 */ 633 transaction_t *t_cpnext, *t_cpprev; 634 635 /* 636 * When will the transaction expire (become due for commit), in jiffies? 637 * [no locking] 638 */ 639 unsigned long t_expires; 640 641 /* 642 * When this transaction started, in nanoseconds [no locking] 643 */ 644 ktime_t t_start_time; 645 646 /* 647 * How many handles used this transaction? [t_handle_lock] 648 */ 649 int t_handle_count; 650 651 /* 652 * This transaction is being forced and some process is 653 * waiting for it to finish. 654 */ 655 unsigned int t_synchronous_commit:1; 656 unsigned int t_flushed_data_blocks:1; 657 658 /* 659 * For use by the filesystem to store fs-specific data 660 * structures associated with the transaction 661 */ 662 struct list_head t_private_list; 663 }; 664 665 struct transaction_run_stats_s { 666 unsigned long rs_wait; 667 unsigned long rs_running; 668 unsigned long rs_locked; 669 unsigned long rs_flushing; 670 unsigned long rs_logging; 671 672 __u32 rs_handle_count; 673 __u32 rs_blocks; 674 __u32 rs_blocks_logged; 675 }; 676 677 struct transaction_stats_s { 678 unsigned long ts_tid; 679 struct transaction_run_stats_s run; 680 }; 681 682 static inline unsigned long 683 jbd2_time_diff(unsigned long start, unsigned long end) 684 { 685 if (end >= start) 686 return end - start; 687 688 return end + (MAX_JIFFY_OFFSET - start); 689 } 690 691 #define JBD2_NR_BATCH 64 692 693 /** 694 * struct journal_s - The journal_s type is the concrete type associated with 695 * journal_t. 696 * @j_flags: General journaling state flags 697 * @j_errno: Is there an outstanding uncleared error on the journal (from a 698 * prior abort)? 699 * @j_sb_buffer: First part of superblock buffer 700 * @j_superblock: Second part of superblock buffer 701 * @j_format_version: Version of the superblock format 702 * @j_state_lock: Protect the various scalars in the journal 703 * @j_barrier_count: Number of processes waiting to create a barrier lock 704 * @j_barrier: The barrier lock itself 705 * @j_running_transaction: The current running transaction.. 706 * @j_committing_transaction: the transaction we are pushing to disk 707 * @j_checkpoint_transactions: a linked circular list of all transactions 708 * waiting for checkpointing 709 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 710 * to start committing, or for a barrier lock to be released 711 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 712 * @j_wait_done_commit: Wait queue for waiting for commit to complete 713 * @j_wait_checkpoint: Wait queue to trigger checkpointing 714 * @j_wait_commit: Wait queue to trigger commit 715 * @j_wait_updates: Wait queue to wait for updates to complete 716 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 717 * @j_head: Journal head - identifies the first unused block in the journal 718 * @j_tail: Journal tail - identifies the oldest still-used block in the 719 * journal. 720 * @j_free: Journal free - how many free blocks are there in the journal? 721 * @j_first: The block number of the first usable block 722 * @j_last: The block number one beyond the last usable block 723 * @j_dev: Device where we store the journal 724 * @j_blocksize: blocksize for the location where we store the journal. 725 * @j_blk_offset: starting block offset for into the device where we store the 726 * journal 727 * @j_fs_dev: Device which holds the client fs. For internal journal this will 728 * be equal to j_dev 729 * @j_maxlen: Total maximum capacity of the journal region on disk. 730 * @j_list_lock: Protects the buffer lists and internal buffer state. 731 * @j_inode: Optional inode where we store the journal. If present, all journal 732 * block numbers are mapped into this inode via bmap(). 733 * @j_tail_sequence: Sequence number of the oldest transaction in the log 734 * @j_transaction_sequence: Sequence number of the next transaction to grant 735 * @j_commit_sequence: Sequence number of the most recently committed 736 * transaction 737 * @j_commit_request: Sequence number of the most recent transaction wanting 738 * commit 739 * @j_uuid: Uuid of client object. 740 * @j_task: Pointer to the current commit thread for this journal 741 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 742 * single compound commit transaction 743 * @j_commit_interval: What is the maximum transaction lifetime before we begin 744 * a commit? 745 * @j_commit_timer: The timer used to wakeup the commit thread 746 * @j_revoke_lock: Protect the revoke table 747 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 748 * current transaction. 749 * @j_revoke_table: alternate revoke tables for j_revoke 750 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 751 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 752 * number that will fit in j_blocksize 753 * @j_last_sync_writer: most recent pid which did a synchronous write 754 * @j_history: Buffer storing the transactions statistics history 755 * @j_history_max: Maximum number of transactions in the statistics history 756 * @j_history_cur: Current number of transactions in the statistics history 757 * @j_history_lock: Protect the transactions statistics history 758 * @j_proc_entry: procfs entry for the jbd statistics directory 759 * @j_stats: Overall statistics 760 * @j_private: An opaque pointer to fs-private information. 761 */ 762 763 struct journal_s 764 { 765 /* General journaling state flags [j_state_lock] */ 766 unsigned long j_flags; 767 768 /* 769 * Is there an outstanding uncleared error on the journal (from a prior 770 * abort)? [j_state_lock] 771 */ 772 int j_errno; 773 774 /* The superblock buffer */ 775 struct buffer_head *j_sb_buffer; 776 journal_superblock_t *j_superblock; 777 778 /* Version of the superblock format */ 779 int j_format_version; 780 781 /* 782 * Protect the various scalars in the journal 783 */ 784 spinlock_t j_state_lock; 785 786 /* 787 * Number of processes waiting to create a barrier lock [j_state_lock] 788 */ 789 int j_barrier_count; 790 791 /* The barrier lock itself */ 792 struct mutex j_barrier; 793 794 /* 795 * Transactions: The current running transaction... 796 * [j_state_lock] [caller holding open handle] 797 */ 798 transaction_t *j_running_transaction; 799 800 /* 801 * the transaction we are pushing to disk 802 * [j_state_lock] [caller holding open handle] 803 */ 804 transaction_t *j_committing_transaction; 805 806 /* 807 * ... and a linked circular list of all transactions waiting for 808 * checkpointing. [j_list_lock] 809 */ 810 transaction_t *j_checkpoint_transactions; 811 812 /* 813 * Wait queue for waiting for a locked transaction to start committing, 814 * or for a barrier lock to be released 815 */ 816 wait_queue_head_t j_wait_transaction_locked; 817 818 /* Wait queue for waiting for checkpointing to complete */ 819 wait_queue_head_t j_wait_logspace; 820 821 /* Wait queue for waiting for commit to complete */ 822 wait_queue_head_t j_wait_done_commit; 823 824 /* Wait queue to trigger checkpointing */ 825 wait_queue_head_t j_wait_checkpoint; 826 827 /* Wait queue to trigger commit */ 828 wait_queue_head_t j_wait_commit; 829 830 /* Wait queue to wait for updates to complete */ 831 wait_queue_head_t j_wait_updates; 832 833 /* Semaphore for locking against concurrent checkpoints */ 834 struct mutex j_checkpoint_mutex; 835 836 /* 837 * List of buffer heads used by the checkpoint routine. This 838 * was moved from jbd2_log_do_checkpoint() to reduce stack 839 * usage. Access to this array is controlled by the 840 * j_checkpoint_mutex. [j_checkpoint_mutex] 841 */ 842 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 843 844 /* 845 * Journal head: identifies the first unused block in the journal. 846 * [j_state_lock] 847 */ 848 unsigned long j_head; 849 850 /* 851 * Journal tail: identifies the oldest still-used block in the journal. 852 * [j_state_lock] 853 */ 854 unsigned long j_tail; 855 856 /* 857 * Journal free: how many free blocks are there in the journal? 858 * [j_state_lock] 859 */ 860 unsigned long j_free; 861 862 /* 863 * Journal start and end: the block numbers of the first usable block 864 * and one beyond the last usable block in the journal. [j_state_lock] 865 */ 866 unsigned long j_first; 867 unsigned long j_last; 868 869 /* 870 * Device, blocksize and starting block offset for the location where we 871 * store the journal. 872 */ 873 struct block_device *j_dev; 874 int j_blocksize; 875 unsigned long long j_blk_offset; 876 char j_devname[BDEVNAME_SIZE+24]; 877 878 /* 879 * Device which holds the client fs. For internal journal this will be 880 * equal to j_dev. 881 */ 882 struct block_device *j_fs_dev; 883 884 /* Total maximum capacity of the journal region on disk. */ 885 unsigned int j_maxlen; 886 887 /* 888 * Protects the buffer lists and internal buffer state. 889 */ 890 spinlock_t j_list_lock; 891 892 /* Optional inode where we store the journal. If present, all */ 893 /* journal block numbers are mapped into this inode via */ 894 /* bmap(). */ 895 struct inode *j_inode; 896 897 /* 898 * Sequence number of the oldest transaction in the log [j_state_lock] 899 */ 900 tid_t j_tail_sequence; 901 902 /* 903 * Sequence number of the next transaction to grant [j_state_lock] 904 */ 905 tid_t j_transaction_sequence; 906 907 /* 908 * Sequence number of the most recently committed transaction 909 * [j_state_lock]. 910 */ 911 tid_t j_commit_sequence; 912 913 /* 914 * Sequence number of the most recent transaction wanting commit 915 * [j_state_lock] 916 */ 917 tid_t j_commit_request; 918 919 /* 920 * Journal uuid: identifies the object (filesystem, LVM volume etc) 921 * backed by this journal. This will eventually be replaced by an array 922 * of uuids, allowing us to index multiple devices within a single 923 * journal and to perform atomic updates across them. 924 */ 925 __u8 j_uuid[16]; 926 927 /* Pointer to the current commit thread for this journal */ 928 struct task_struct *j_task; 929 930 /* 931 * Maximum number of metadata buffers to allow in a single compound 932 * commit transaction 933 */ 934 int j_max_transaction_buffers; 935 936 /* 937 * What is the maximum transaction lifetime before we begin a commit? 938 */ 939 unsigned long j_commit_interval; 940 941 /* The timer used to wakeup the commit thread: */ 942 struct timer_list j_commit_timer; 943 944 /* 945 * The revoke table: maintains the list of revoked blocks in the 946 * current transaction. [j_revoke_lock] 947 */ 948 spinlock_t j_revoke_lock; 949 struct jbd2_revoke_table_s *j_revoke; 950 struct jbd2_revoke_table_s *j_revoke_table[2]; 951 952 /* 953 * array of bhs for jbd2_journal_commit_transaction 954 */ 955 struct buffer_head **j_wbuf; 956 int j_wbufsize; 957 958 /* 959 * this is the pid of hte last person to run a synchronous operation 960 * through the journal 961 */ 962 pid_t j_last_sync_writer; 963 964 /* 965 * the average amount of time in nanoseconds it takes to commit a 966 * transaction to disk. [j_state_lock] 967 */ 968 u64 j_average_commit_time; 969 970 /* 971 * minimum and maximum times that we should wait for 972 * additional filesystem operations to get batched into a 973 * synchronous handle in microseconds 974 */ 975 u32 j_min_batch_time; 976 u32 j_max_batch_time; 977 978 /* This function is called when a transaction is closed */ 979 void (*j_commit_callback)(journal_t *, 980 transaction_t *); 981 982 /* 983 * Journal statistics 984 */ 985 spinlock_t j_history_lock; 986 struct proc_dir_entry *j_proc_entry; 987 struct transaction_stats_s j_stats; 988 989 /* Failed journal commit ID */ 990 unsigned int j_failed_commit; 991 992 /* 993 * An opaque pointer to fs-private information. ext3 puts its 994 * superblock pointer here 995 */ 996 void *j_private; 997 }; 998 999 /* 1000 * Journal flag definitions 1001 */ 1002 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 1003 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 1004 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 1005 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 1006 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 1007 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 1008 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 1009 * data write error in ordered 1010 * mode */ 1011 1012 /* 1013 * Function declarations for the journaling transaction and buffer 1014 * management 1015 */ 1016 1017 /* Filing buffers */ 1018 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 1019 extern void __jbd2_journal_unfile_buffer(struct journal_head *); 1020 extern void __jbd2_journal_refile_buffer(struct journal_head *); 1021 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 1022 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1023 extern void __journal_free_buffer(struct journal_head *bh); 1024 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1025 extern void __journal_clean_data_list(transaction_t *transaction); 1026 1027 /* Log buffer allocation */ 1028 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 1029 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 1030 1031 /* Commit management */ 1032 extern void jbd2_journal_commit_transaction(journal_t *); 1033 1034 /* Checkpoint list management */ 1035 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 1036 int __jbd2_journal_remove_checkpoint(struct journal_head *); 1037 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1038 1039 1040 /* 1041 * Triggers 1042 */ 1043 1044 struct jbd2_buffer_trigger_type { 1045 /* 1046 * Fired just before a buffer is written to the journal. 1047 * mapped_data is a mapped buffer that is the frozen data for 1048 * commit. 1049 */ 1050 void (*t_commit)(struct jbd2_buffer_trigger_type *type, 1051 struct buffer_head *bh, void *mapped_data, 1052 size_t size); 1053 1054 /* 1055 * Fired during journal abort for dirty buffers that will not be 1056 * committed. 1057 */ 1058 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1059 struct buffer_head *bh); 1060 }; 1061 1062 extern void jbd2_buffer_commit_trigger(struct journal_head *jh, 1063 void *mapped_data, 1064 struct jbd2_buffer_trigger_type *triggers); 1065 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1066 struct jbd2_buffer_trigger_type *triggers); 1067 1068 /* Buffer IO */ 1069 extern int 1070 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1071 struct journal_head *jh_in, 1072 struct journal_head **jh_out, 1073 unsigned long long blocknr); 1074 1075 /* Transaction locking */ 1076 extern void __wait_on_journal (journal_t *); 1077 1078 /* 1079 * Journal locking. 1080 * 1081 * We need to lock the journal during transaction state changes so that nobody 1082 * ever tries to take a handle on the running transaction while we are in the 1083 * middle of moving it to the commit phase. j_state_lock does this. 1084 * 1085 * Note that the locking is completely interrupt unsafe. We never touch 1086 * journal structures from interrupts. 1087 */ 1088 1089 static inline handle_t *journal_current_handle(void) 1090 { 1091 return current->journal_info; 1092 } 1093 1094 /* The journaling code user interface: 1095 * 1096 * Create and destroy handles 1097 * Register buffer modifications against the current transaction. 1098 */ 1099 1100 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1101 extern int jbd2_journal_restart (handle_t *, int nblocks); 1102 extern int jbd2_journal_extend (handle_t *, int nblocks); 1103 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1104 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1105 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1106 void jbd2_journal_set_triggers(struct buffer_head *, 1107 struct jbd2_buffer_trigger_type *type); 1108 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1109 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 1110 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1111 extern void journal_sync_buffer (struct buffer_head *); 1112 extern void jbd2_journal_invalidatepage(journal_t *, 1113 struct page *, unsigned long); 1114 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1115 extern int jbd2_journal_stop(handle_t *); 1116 extern int jbd2_journal_flush (journal_t *); 1117 extern void jbd2_journal_lock_updates (journal_t *); 1118 extern void jbd2_journal_unlock_updates (journal_t *); 1119 1120 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1121 struct block_device *fs_dev, 1122 unsigned long long start, int len, int bsize); 1123 extern journal_t * jbd2_journal_init_inode (struct inode *); 1124 extern int jbd2_journal_update_format (journal_t *); 1125 extern int jbd2_journal_check_used_features 1126 (journal_t *, unsigned long, unsigned long, unsigned long); 1127 extern int jbd2_journal_check_available_features 1128 (journal_t *, unsigned long, unsigned long, unsigned long); 1129 extern int jbd2_journal_set_features 1130 (journal_t *, unsigned long, unsigned long, unsigned long); 1131 extern void jbd2_journal_clear_features 1132 (journal_t *, unsigned long, unsigned long, unsigned long); 1133 extern int jbd2_journal_load (journal_t *journal); 1134 extern int jbd2_journal_destroy (journal_t *); 1135 extern int jbd2_journal_recover (journal_t *journal); 1136 extern int jbd2_journal_wipe (journal_t *, int); 1137 extern int jbd2_journal_skip_recovery (journal_t *); 1138 extern void jbd2_journal_update_superblock (journal_t *, int); 1139 extern void __jbd2_journal_abort_hard (journal_t *); 1140 extern void jbd2_journal_abort (journal_t *, int); 1141 extern int jbd2_journal_errno (journal_t *); 1142 extern void jbd2_journal_ack_err (journal_t *); 1143 extern int jbd2_journal_clear_err (journal_t *); 1144 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1145 extern int jbd2_journal_force_commit(journal_t *); 1146 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1147 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1148 struct jbd2_inode *inode, loff_t new_size); 1149 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1150 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1151 1152 /* 1153 * journal_head management 1154 */ 1155 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1156 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1157 void jbd2_journal_remove_journal_head(struct buffer_head *bh); 1158 void jbd2_journal_put_journal_head(struct journal_head *jh); 1159 1160 /* 1161 * handle management 1162 */ 1163 extern struct kmem_cache *jbd2_handle_cache; 1164 1165 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1166 { 1167 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 1168 } 1169 1170 static inline void jbd2_free_handle(handle_t *handle) 1171 { 1172 kmem_cache_free(jbd2_handle_cache, handle); 1173 } 1174 1175 /* Primary revoke support */ 1176 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1177 extern int jbd2_journal_init_revoke(journal_t *, int); 1178 extern void jbd2_journal_destroy_revoke_caches(void); 1179 extern int jbd2_journal_init_revoke_caches(void); 1180 1181 extern void jbd2_journal_destroy_revoke(journal_t *); 1182 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1183 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1184 extern void jbd2_journal_write_revoke_records(journal_t *, 1185 transaction_t *, int); 1186 1187 /* Recovery revoke support */ 1188 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1189 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1190 extern void jbd2_journal_clear_revoke(journal_t *); 1191 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1192 1193 /* 1194 * The log thread user interface: 1195 * 1196 * Request space in the current transaction, and force transaction commit 1197 * transitions on demand. 1198 */ 1199 1200 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 1201 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1202 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1203 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1204 int jbd2_journal_force_commit_nested(journal_t *journal); 1205 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1206 int jbd2_log_do_checkpoint(journal_t *journal); 1207 1208 void __jbd2_log_wait_for_space(journal_t *journal); 1209 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1210 extern int jbd2_cleanup_journal_tail(journal_t *); 1211 1212 /* Debugging code only: */ 1213 1214 #define jbd_ENOSYS() \ 1215 do { \ 1216 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \ 1217 current->state = TASK_UNINTERRUPTIBLE; \ 1218 schedule(); \ 1219 } while (1) 1220 1221 /* 1222 * is_journal_abort 1223 * 1224 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1225 * bit, when set, indicates that we have had a fatal error somewhere, 1226 * either inside the journaling layer or indicated to us by the client 1227 * (eg. ext3), and that we and should not commit any further 1228 * transactions. 1229 */ 1230 1231 static inline int is_journal_aborted(journal_t *journal) 1232 { 1233 return journal->j_flags & JBD2_ABORT; 1234 } 1235 1236 static inline int is_handle_aborted(handle_t *handle) 1237 { 1238 if (handle->h_aborted) 1239 return 1; 1240 return is_journal_aborted(handle->h_transaction->t_journal); 1241 } 1242 1243 static inline void jbd2_journal_abort_handle(handle_t *handle) 1244 { 1245 handle->h_aborted = 1; 1246 } 1247 1248 #endif /* __KERNEL__ */ 1249 1250 /* Comparison functions for transaction IDs: perform comparisons using 1251 * modulo arithmetic so that they work over sequence number wraps. */ 1252 1253 static inline int tid_gt(tid_t x, tid_t y) 1254 { 1255 int difference = (x - y); 1256 return (difference > 0); 1257 } 1258 1259 static inline int tid_geq(tid_t x, tid_t y) 1260 { 1261 int difference = (x - y); 1262 return (difference >= 0); 1263 } 1264 1265 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1266 extern size_t journal_tag_bytes(journal_t *journal); 1267 1268 /* 1269 * Return the minimum number of blocks which must be free in the journal 1270 * before a new transaction may be started. Must be called under j_state_lock. 1271 */ 1272 static inline int jbd_space_needed(journal_t *journal) 1273 { 1274 int nblocks = journal->j_max_transaction_buffers; 1275 if (journal->j_committing_transaction) 1276 nblocks += journal->j_committing_transaction-> 1277 t_outstanding_credits; 1278 return nblocks; 1279 } 1280 1281 /* 1282 * Definitions which augment the buffer_head layer 1283 */ 1284 1285 /* journaling buffer types */ 1286 #define BJ_None 0 /* Not journaled */ 1287 #define BJ_Metadata 1 /* Normal journaled metadata */ 1288 #define BJ_Forget 2 /* Buffer superseded by this transaction */ 1289 #define BJ_IO 3 /* Buffer is for temporary IO use */ 1290 #define BJ_Shadow 4 /* Buffer contents being shadowed to the log */ 1291 #define BJ_LogCtl 5 /* Buffer contains log descriptors */ 1292 #define BJ_Reserved 6 /* Buffer is reserved for access by journal */ 1293 #define BJ_Types 7 1294 1295 extern int jbd_blocks_per_page(struct inode *inode); 1296 1297 #ifdef __KERNEL__ 1298 1299 #define buffer_trace_init(bh) do {} while (0) 1300 #define print_buffer_fields(bh) do {} while (0) 1301 #define print_buffer_trace(bh) do {} while (0) 1302 #define BUFFER_TRACE(bh, info) do {} while (0) 1303 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1304 #define JBUFFER_TRACE(jh, info) do {} while (0) 1305 1306 /* 1307 * jbd2_dev_to_name is a utility function used by the jbd2 and ext4 1308 * tracing infrastructure to map a dev_t to a device name. 1309 */ 1310 extern const char *jbd2_dev_to_name(dev_t device); 1311 1312 #endif /* __KERNEL__ */ 1313 1314 #endif /* _LINUX_JBD2_H */ 1315