1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * linux/include/linux/jbd2.h 4 * 5 * Written by Stephen C. Tweedie <sct@redhat.com> 6 * 7 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 8 * 9 * Definitions for transaction data structures for the buffer cache 10 * filesystem journaling support. 11 */ 12 13 #ifndef _LINUX_JBD2_H 14 #define _LINUX_JBD2_H 15 16 /* Allow this file to be included directly into e2fsprogs */ 17 #ifndef __KERNEL__ 18 #include "jfs_compat.h" 19 #define JBD2_DEBUG 20 #else 21 22 #include <linux/types.h> 23 #include <linux/buffer_head.h> 24 #include <linux/journal-head.h> 25 #include <linux/stddef.h> 26 #include <linux/mutex.h> 27 #include <linux/timer.h> 28 #include <linux/slab.h> 29 #include <linux/bit_spinlock.h> 30 #include <linux/blkdev.h> 31 #include <crypto/hash.h> 32 #endif 33 34 #define journal_oom_retry 1 35 36 /* 37 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 38 * certain classes of error which can occur due to failed IOs. Under 39 * normal use we want ext4 to continue after such errors, because 40 * hardware _can_ fail, but for debugging purposes when running tests on 41 * known-good hardware we may want to trap these errors. 42 */ 43 #undef JBD2_PARANOID_IOFAIL 44 45 /* 46 * The default maximum commit age, in seconds. 47 */ 48 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 49 50 #ifdef CONFIG_JBD2_DEBUG 51 /* 52 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 53 * consistency checks. By default we don't do this unless 54 * CONFIG_JBD2_DEBUG is on. 55 */ 56 #define JBD2_EXPENSIVE_CHECKING 57 extern ushort jbd2_journal_enable_debug; 58 void __jbd2_debug(int level, const char *file, const char *func, 59 unsigned int line, const char *fmt, ...); 60 61 #define jbd_debug(n, fmt, a...) \ 62 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a) 63 #else 64 #define jbd_debug(n, fmt, a...) no_printk(fmt, ##a) 65 #endif 66 67 extern void *jbd2_alloc(size_t size, gfp_t flags); 68 extern void jbd2_free(void *ptr, size_t size); 69 70 #define JBD2_MIN_JOURNAL_BLOCKS 1024 71 #define JBD2_DEFAULT_FAST_COMMIT_BLOCKS 256 72 73 #ifdef __KERNEL__ 74 75 /** 76 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 77 * 78 * All filesystem modifications made by the process go 79 * through this handle. Recursive operations (such as quota operations) 80 * are gathered into a single update. 81 * 82 * The buffer credits field is used to account for journaled buffers 83 * being modified by the running process. To ensure that there is 84 * enough log space for all outstanding operations, we need to limit the 85 * number of outstanding buffers possible at any time. When the 86 * operation completes, any buffer credits not used are credited back to 87 * the transaction, so that at all times we know how many buffers the 88 * outstanding updates on a transaction might possibly touch. 89 * 90 * This is an opaque datatype. 91 **/ 92 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */ 93 94 95 /** 96 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 97 * 98 * journal_t is linked to from the fs superblock structure. 99 * 100 * We use the journal_t to keep track of all outstanding transaction 101 * activity on the filesystem, and to manage the state of the log 102 * writing process. 103 * 104 * This is an opaque datatype. 105 **/ 106 typedef struct journal_s journal_t; /* Journal control structure */ 107 #endif 108 109 /* 110 * Internal structures used by the logging mechanism: 111 */ 112 113 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 114 115 /* 116 * On-disk structures 117 */ 118 119 /* 120 * Descriptor block types: 121 */ 122 123 #define JBD2_DESCRIPTOR_BLOCK 1 124 #define JBD2_COMMIT_BLOCK 2 125 #define JBD2_SUPERBLOCK_V1 3 126 #define JBD2_SUPERBLOCK_V2 4 127 #define JBD2_REVOKE_BLOCK 5 128 129 /* 130 * Standard header for all descriptor blocks: 131 */ 132 typedef struct journal_header_s 133 { 134 __be32 h_magic; 135 __be32 h_blocktype; 136 __be32 h_sequence; 137 } journal_header_t; 138 139 /* 140 * Checksum types. 141 */ 142 #define JBD2_CRC32_CHKSUM 1 143 #define JBD2_MD5_CHKSUM 2 144 #define JBD2_SHA1_CHKSUM 3 145 #define JBD2_CRC32C_CHKSUM 4 146 147 #define JBD2_CRC32_CHKSUM_SIZE 4 148 149 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 150 /* 151 * Commit block header for storing transactional checksums: 152 * 153 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* 154 * fields are used to store a checksum of the descriptor and data blocks. 155 * 156 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum 157 * field is used to store crc32c(uuid+commit_block). Each journal metadata 158 * block gets its own checksum, and data block checksums are stored in 159 * journal_block_tag (in the descriptor). The other h_chksum* fields are 160 * not used. 161 * 162 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses 163 * journal_block_tag3_t to store a full 32-bit checksum. Everything else 164 * is the same as v2. 165 * 166 * Checksum v1, v2, and v3 are mutually exclusive features. 167 */ 168 struct commit_header { 169 __be32 h_magic; 170 __be32 h_blocktype; 171 __be32 h_sequence; 172 unsigned char h_chksum_type; 173 unsigned char h_chksum_size; 174 unsigned char h_padding[2]; 175 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 176 __be64 h_commit_sec; 177 __be32 h_commit_nsec; 178 }; 179 180 /* 181 * The block tag: used to describe a single buffer in the journal. 182 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 183 * raw struct shouldn't be used for pointer math or sizeof() - use 184 * journal_tag_bytes(journal) instead to compute this. 185 */ 186 typedef struct journal_block_tag3_s 187 { 188 __be32 t_blocknr; /* The on-disk block number */ 189 __be32 t_flags; /* See below */ 190 __be32 t_blocknr_high; /* most-significant high 32bits. */ 191 __be32 t_checksum; /* crc32c(uuid+seq+block) */ 192 } journal_block_tag3_t; 193 194 typedef struct journal_block_tag_s 195 { 196 __be32 t_blocknr; /* The on-disk block number */ 197 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ 198 __be16 t_flags; /* See below */ 199 __be32 t_blocknr_high; /* most-significant high 32bits. */ 200 } journal_block_tag_t; 201 202 /* Tail of descriptor or revoke block, for checksumming */ 203 struct jbd2_journal_block_tail { 204 __be32 t_checksum; /* crc32c(uuid+descr_block) */ 205 }; 206 207 /* 208 * The revoke descriptor: used on disk to describe a series of blocks to 209 * be revoked from the log 210 */ 211 typedef struct jbd2_journal_revoke_header_s 212 { 213 journal_header_t r_header; 214 __be32 r_count; /* Count of bytes used in the block */ 215 } jbd2_journal_revoke_header_t; 216 217 /* Definitions for the journal tag flags word: */ 218 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 219 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 220 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 221 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 222 223 224 /* 225 * The journal superblock. All fields are in big-endian byte order. 226 */ 227 typedef struct journal_superblock_s 228 { 229 /* 0x0000 */ 230 journal_header_t s_header; 231 232 /* 0x000C */ 233 /* Static information describing the journal */ 234 __be32 s_blocksize; /* journal device blocksize */ 235 __be32 s_maxlen; /* total blocks in journal file */ 236 __be32 s_first; /* first block of log information */ 237 238 /* 0x0018 */ 239 /* Dynamic information describing the current state of the log */ 240 __be32 s_sequence; /* first commit ID expected in log */ 241 __be32 s_start; /* blocknr of start of log */ 242 243 /* 0x0020 */ 244 /* Error value, as set by jbd2_journal_abort(). */ 245 __be32 s_errno; 246 247 /* 0x0024 */ 248 /* Remaining fields are only valid in a version-2 superblock */ 249 __be32 s_feature_compat; /* compatible feature set */ 250 __be32 s_feature_incompat; /* incompatible feature set */ 251 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 252 /* 0x0030 */ 253 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 254 255 /* 0x0040 */ 256 __be32 s_nr_users; /* Nr of filesystems sharing log */ 257 258 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 259 260 /* 0x0048 */ 261 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 262 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 263 264 /* 0x0050 */ 265 __u8 s_checksum_type; /* checksum type */ 266 __u8 s_padding2[3]; 267 /* 0x0054 */ 268 __be32 s_num_fc_blks; /* Number of fast commit blocks */ 269 /* 0x0058 */ 270 __u32 s_padding[41]; 271 __be32 s_checksum; /* crc32c(superblock) */ 272 273 /* 0x0100 */ 274 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 275 /* 0x0400 */ 276 } journal_superblock_t; 277 278 /* Use the jbd2_{has,set,clear}_feature_* helpers; these will be removed */ 279 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 280 ((j)->j_format_version >= 2 && \ 281 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 282 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 283 ((j)->j_format_version >= 2 && \ 284 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 285 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 286 ((j)->j_format_version >= 2 && \ 287 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 288 289 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 290 291 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 292 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 293 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 294 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 295 #define JBD2_FEATURE_INCOMPAT_CSUM_V3 0x00000010 296 #define JBD2_FEATURE_INCOMPAT_FAST_COMMIT 0x00000020 297 298 /* See "journal feature predicate functions" below */ 299 300 /* Features known to this kernel version: */ 301 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 302 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 303 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 304 JBD2_FEATURE_INCOMPAT_64BIT | \ 305 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \ 306 JBD2_FEATURE_INCOMPAT_CSUM_V2 | \ 307 JBD2_FEATURE_INCOMPAT_CSUM_V3 | \ 308 JBD2_FEATURE_INCOMPAT_FAST_COMMIT) 309 310 #ifdef __KERNEL__ 311 312 #include <linux/fs.h> 313 #include <linux/sched.h> 314 315 enum jbd_state_bits { 316 BH_JBD /* Has an attached ext3 journal_head */ 317 = BH_PrivateStart, 318 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 319 BH_Freed, /* Has been freed (truncated) */ 320 BH_Revoked, /* Has been revoked from the log */ 321 BH_RevokeValid, /* Revoked flag is valid */ 322 BH_JBDDirty, /* Is dirty but journaled */ 323 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 324 BH_Shadow, /* IO on shadow buffer is running */ 325 BH_Verified, /* Metadata block has been verified ok */ 326 BH_JBDPrivateStart, /* First bit available for private use by FS */ 327 }; 328 329 BUFFER_FNS(JBD, jbd) 330 BUFFER_FNS(JWrite, jwrite) 331 BUFFER_FNS(JBDDirty, jbddirty) 332 TAS_BUFFER_FNS(JBDDirty, jbddirty) 333 BUFFER_FNS(Revoked, revoked) 334 TAS_BUFFER_FNS(Revoked, revoked) 335 BUFFER_FNS(RevokeValid, revokevalid) 336 TAS_BUFFER_FNS(RevokeValid, revokevalid) 337 BUFFER_FNS(Freed, freed) 338 BUFFER_FNS(Shadow, shadow) 339 BUFFER_FNS(Verified, verified) 340 341 static inline struct buffer_head *jh2bh(struct journal_head *jh) 342 { 343 return jh->b_bh; 344 } 345 346 static inline struct journal_head *bh2jh(struct buffer_head *bh) 347 { 348 return bh->b_private; 349 } 350 351 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) 352 { 353 bit_spin_lock(BH_JournalHead, &bh->b_state); 354 } 355 356 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) 357 { 358 bit_spin_unlock(BH_JournalHead, &bh->b_state); 359 } 360 361 #define J_ASSERT(assert) BUG_ON(!(assert)) 362 363 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 364 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 365 366 #if defined(JBD2_PARANOID_IOFAIL) 367 #define J_EXPECT(expr, why...) J_ASSERT(expr) 368 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 369 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 370 #else 371 #define __journal_expect(expr, why...) \ 372 ({ \ 373 int val = (expr); \ 374 if (!val) { \ 375 printk(KERN_ERR \ 376 "JBD2 unexpected failure: %s: %s;\n", \ 377 __func__, #expr); \ 378 printk(KERN_ERR why "\n"); \ 379 } \ 380 val; \ 381 }) 382 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 383 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 384 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 385 #endif 386 387 /* Flags in jbd_inode->i_flags */ 388 #define __JI_COMMIT_RUNNING 0 389 #define __JI_WRITE_DATA 1 390 #define __JI_WAIT_DATA 2 391 392 /* 393 * Commit of the inode data in progress. We use this flag to protect us from 394 * concurrent deletion of inode. We cannot use reference to inode for this 395 * since we cannot afford doing last iput() on behalf of kjournald 396 */ 397 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 398 /* Write allocated dirty buffers in this inode before commit */ 399 #define JI_WRITE_DATA (1 << __JI_WRITE_DATA) 400 /* Wait for outstanding data writes for this inode before commit */ 401 #define JI_WAIT_DATA (1 << __JI_WAIT_DATA) 402 403 /** 404 * struct jbd2_inode - The jbd_inode type is the structure linking inodes in 405 * ordered mode present in a transaction so that we can sync them during commit. 406 */ 407 struct jbd2_inode { 408 /** 409 * @i_transaction: 410 * 411 * Which transaction does this inode belong to? Either the running 412 * transaction or the committing one. [j_list_lock] 413 */ 414 transaction_t *i_transaction; 415 416 /** 417 * @i_next_transaction: 418 * 419 * Pointer to the running transaction modifying inode's data in case 420 * there is already a committing transaction touching it. [j_list_lock] 421 */ 422 transaction_t *i_next_transaction; 423 424 /** 425 * @i_list: List of inodes in the i_transaction [j_list_lock] 426 */ 427 struct list_head i_list; 428 429 /** 430 * @i_vfs_inode: 431 * 432 * VFS inode this inode belongs to [constant for lifetime of structure] 433 */ 434 struct inode *i_vfs_inode; 435 436 /** 437 * @i_flags: Flags of inode [j_list_lock] 438 */ 439 unsigned long i_flags; 440 441 /** 442 * @i_dirty_start: 443 * 444 * Offset in bytes where the dirty range for this inode starts. 445 * [j_list_lock] 446 */ 447 loff_t i_dirty_start; 448 449 /** 450 * @i_dirty_end: 451 * 452 * Inclusive offset in bytes where the dirty range for this inode 453 * ends. [j_list_lock] 454 */ 455 loff_t i_dirty_end; 456 }; 457 458 struct jbd2_revoke_table_s; 459 460 /** 461 * struct jbd2_journal_handle - The jbd2_journal_handle type is the concrete 462 * type associated with handle_t. 463 * @h_transaction: Which compound transaction is this update a part of? 464 * @h_journal: Which journal handle belongs to - used iff h_reserved set. 465 * @h_rsv_handle: Handle reserved for finishing the logical operation. 466 * @h_total_credits: Number of remaining buffers we are allowed to add to 467 * journal. These are dirty buffers and revoke descriptor blocks. 468 * @h_revoke_credits: Number of remaining revoke records available for handle 469 * @h_ref: Reference count on this handle. 470 * @h_err: Field for caller's use to track errors through large fs operations. 471 * @h_sync: Flag for sync-on-close. 472 * @h_jdata: Flag to force data journaling. 473 * @h_reserved: Flag for handle for reserved credits. 474 * @h_aborted: Flag indicating fatal error on handle. 475 * @h_type: For handle statistics. 476 * @h_line_no: For handle statistics. 477 * @h_start_jiffies: Handle Start time. 478 * @h_requested_credits: Holds @h_total_credits after handle is started. 479 * @h_revoke_credits_requested: Holds @h_revoke_credits after handle is started. 480 * @saved_alloc_context: Saved context while transaction is open. 481 **/ 482 483 /* Docbook can't yet cope with the bit fields, but will leave the documentation 484 * in so it can be fixed later. 485 */ 486 487 struct jbd2_journal_handle 488 { 489 union { 490 transaction_t *h_transaction; 491 /* Which journal handle belongs to - used iff h_reserved set */ 492 journal_t *h_journal; 493 }; 494 495 handle_t *h_rsv_handle; 496 int h_total_credits; 497 int h_revoke_credits; 498 int h_revoke_credits_requested; 499 int h_ref; 500 int h_err; 501 502 /* Flags [no locking] */ 503 unsigned int h_sync: 1; 504 unsigned int h_jdata: 1; 505 unsigned int h_reserved: 1; 506 unsigned int h_aborted: 1; 507 unsigned int h_type: 8; 508 unsigned int h_line_no: 16; 509 510 unsigned long h_start_jiffies; 511 unsigned int h_requested_credits; 512 513 unsigned int saved_alloc_context; 514 }; 515 516 517 /* 518 * Some stats for checkpoint phase 519 */ 520 struct transaction_chp_stats_s { 521 unsigned long cs_chp_time; 522 __u32 cs_forced_to_close; 523 __u32 cs_written; 524 __u32 cs_dropped; 525 }; 526 527 /* The transaction_t type is the guts of the journaling mechanism. It 528 * tracks a compound transaction through its various states: 529 * 530 * RUNNING: accepting new updates 531 * LOCKED: Updates still running but we don't accept new ones 532 * RUNDOWN: Updates are tidying up but have finished requesting 533 * new buffers to modify (state not used for now) 534 * FLUSH: All updates complete, but we are still writing to disk 535 * COMMIT: All data on disk, writing commit record 536 * FINISHED: We still have to keep the transaction for checkpointing. 537 * 538 * The transaction keeps track of all of the buffers modified by a 539 * running transaction, and all of the buffers committed but not yet 540 * flushed to home for finished transactions. 541 * (Locking Documentation improved by LockDoc) 542 */ 543 544 /* 545 * Lock ranking: 546 * 547 * j_list_lock 548 * ->jbd_lock_bh_journal_head() (This is "innermost") 549 * 550 * j_state_lock 551 * ->b_state_lock 552 * 553 * b_state_lock 554 * ->j_list_lock 555 * 556 * j_state_lock 557 * ->t_handle_lock 558 * 559 * j_state_lock 560 * ->j_list_lock (journal_unmap_buffer) 561 * 562 */ 563 564 struct transaction_s 565 { 566 /* Pointer to the journal for this transaction. [no locking] */ 567 journal_t *t_journal; 568 569 /* Sequence number for this transaction [no locking] */ 570 tid_t t_tid; 571 572 /* 573 * Transaction's current state 574 * [no locking - only kjournald2 alters this] 575 * [j_list_lock] guards transition of a transaction into T_FINISHED 576 * state and subsequent call of __jbd2_journal_drop_transaction() 577 * FIXME: needs barriers 578 * KLUDGE: [use j_state_lock] 579 */ 580 enum { 581 T_RUNNING, 582 T_LOCKED, 583 T_SWITCH, 584 T_FLUSH, 585 T_COMMIT, 586 T_COMMIT_DFLUSH, 587 T_COMMIT_JFLUSH, 588 T_COMMIT_CALLBACK, 589 T_FINISHED 590 } t_state; 591 592 /* 593 * Where in the log does this transaction's commit start? [no locking] 594 */ 595 unsigned long t_log_start; 596 597 /* 598 * Number of buffers on the t_buffers list [j_list_lock, no locks 599 * needed for jbd2 thread] 600 */ 601 int t_nr_buffers; 602 603 /* 604 * Doubly-linked circular list of all buffers reserved but not yet 605 * modified by this transaction [j_list_lock, no locks needed fo 606 * jbd2 thread] 607 */ 608 struct journal_head *t_reserved_list; 609 610 /* 611 * Doubly-linked circular list of all metadata buffers owned by this 612 * transaction [j_list_lock, no locks needed for jbd2 thread] 613 */ 614 struct journal_head *t_buffers; 615 616 /* 617 * Doubly-linked circular list of all forget buffers (superseded 618 * buffers which we can un-checkpoint once this transaction commits) 619 * [j_list_lock] 620 */ 621 struct journal_head *t_forget; 622 623 /* 624 * Doubly-linked circular list of all buffers still to be flushed before 625 * this transaction can be checkpointed. [j_list_lock] 626 */ 627 struct journal_head *t_checkpoint_list; 628 629 /* 630 * Doubly-linked circular list of all buffers submitted for IO while 631 * checkpointing. [j_list_lock] 632 */ 633 struct journal_head *t_checkpoint_io_list; 634 635 /* 636 * Doubly-linked circular list of metadata buffers being 637 * shadowed by log IO. The IO buffers on the iobuf list and 638 * the shadow buffers on this list match each other one for 639 * one at all times. [j_list_lock, no locks needed for jbd2 640 * thread] 641 */ 642 struct journal_head *t_shadow_list; 643 644 /* 645 * List of inodes associated with the transaction; e.g., ext4 uses 646 * this to track inodes in data=ordered and data=journal mode that 647 * need special handling on transaction commit; also used by ocfs2. 648 * [j_list_lock] 649 */ 650 struct list_head t_inode_list; 651 652 /* 653 * Protects info related to handles 654 */ 655 spinlock_t t_handle_lock; 656 657 /* 658 * Longest time some handle had to wait for running transaction 659 */ 660 unsigned long t_max_wait; 661 662 /* 663 * When transaction started 664 */ 665 unsigned long t_start; 666 667 /* 668 * When commit was requested [j_state_lock] 669 */ 670 unsigned long t_requested; 671 672 /* 673 * Checkpointing stats [j_list_lock] 674 */ 675 struct transaction_chp_stats_s t_chp_stats; 676 677 /* 678 * Number of outstanding updates running on this transaction 679 * [none] 680 */ 681 atomic_t t_updates; 682 683 /* 684 * Number of blocks reserved for this transaction in the journal. 685 * This is including all credits reserved when starting transaction 686 * handles as well as all journal descriptor blocks needed for this 687 * transaction. [none] 688 */ 689 atomic_t t_outstanding_credits; 690 691 /* 692 * Number of revoke records for this transaction added by already 693 * stopped handles. [none] 694 */ 695 atomic_t t_outstanding_revokes; 696 697 /* 698 * How many handles used this transaction? [none] 699 */ 700 atomic_t t_handle_count; 701 702 /* 703 * Forward and backward links for the circular list of all transactions 704 * awaiting checkpoint. [j_list_lock] 705 */ 706 transaction_t *t_cpnext, *t_cpprev; 707 708 /* 709 * When will the transaction expire (become due for commit), in jiffies? 710 * [no locking] 711 */ 712 unsigned long t_expires; 713 714 /* 715 * When this transaction started, in nanoseconds [no locking] 716 */ 717 ktime_t t_start_time; 718 719 /* 720 * This transaction is being forced and some process is 721 * waiting for it to finish. 722 */ 723 unsigned int t_synchronous_commit:1; 724 725 /* Disk flush needs to be sent to fs partition [no locking] */ 726 int t_need_data_flush; 727 728 /* 729 * For use by the filesystem to store fs-specific data 730 * structures associated with the transaction 731 */ 732 struct list_head t_private_list; 733 }; 734 735 struct transaction_run_stats_s { 736 unsigned long rs_wait; 737 unsigned long rs_request_delay; 738 unsigned long rs_running; 739 unsigned long rs_locked; 740 unsigned long rs_flushing; 741 unsigned long rs_logging; 742 743 __u32 rs_handle_count; 744 __u32 rs_blocks; 745 __u32 rs_blocks_logged; 746 }; 747 748 struct transaction_stats_s { 749 unsigned long ts_tid; 750 unsigned long ts_requested; 751 struct transaction_run_stats_s run; 752 }; 753 754 static inline unsigned long 755 jbd2_time_diff(unsigned long start, unsigned long end) 756 { 757 if (end >= start) 758 return end - start; 759 760 return end + (MAX_JIFFY_OFFSET - start); 761 } 762 763 #define JBD2_NR_BATCH 64 764 765 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; 766 767 #define JBD2_FC_REPLAY_STOP 0 768 #define JBD2_FC_REPLAY_CONTINUE 1 769 770 /** 771 * struct journal_s - The journal_s type is the concrete type associated with 772 * journal_t. 773 */ 774 struct journal_s 775 { 776 /** 777 * @j_flags: General journaling state flags [j_state_lock, 778 * no lock for quick racy checks] 779 */ 780 unsigned long j_flags; 781 782 /** 783 * @j_atomic_flags: Atomic journaling state flags. 784 */ 785 unsigned long j_atomic_flags; 786 787 /** 788 * @j_errno: 789 * 790 * Is there an outstanding uncleared error on the journal (from a prior 791 * abort)? [j_state_lock] 792 */ 793 int j_errno; 794 795 /** 796 * @j_abort_mutex: Lock the whole aborting procedure. 797 */ 798 struct mutex j_abort_mutex; 799 800 /** 801 * @j_sb_buffer: The first part of the superblock buffer. 802 */ 803 struct buffer_head *j_sb_buffer; 804 805 /** 806 * @j_superblock: The second part of the superblock buffer. 807 */ 808 journal_superblock_t *j_superblock; 809 810 /** 811 * @j_format_version: Version of the superblock format. 812 */ 813 int j_format_version; 814 815 /** 816 * @j_state_lock: Protect the various scalars in the journal. 817 */ 818 rwlock_t j_state_lock; 819 820 /** 821 * @j_barrier_count: 822 * 823 * Number of processes waiting to create a barrier lock [j_state_lock, 824 * no lock for quick racy checks] 825 */ 826 int j_barrier_count; 827 828 /** 829 * @j_barrier: The barrier lock itself. 830 */ 831 struct mutex j_barrier; 832 833 /** 834 * @j_running_transaction: 835 * 836 * Transactions: The current running transaction... 837 * [j_state_lock, no lock for quick racy checks] [caller holding 838 * open handle] 839 */ 840 transaction_t *j_running_transaction; 841 842 /** 843 * @j_committing_transaction: 844 * 845 * the transaction we are pushing to disk 846 * [j_state_lock] [caller holding open handle] 847 */ 848 transaction_t *j_committing_transaction; 849 850 /** 851 * @j_checkpoint_transactions: 852 * 853 * ... and a linked circular list of all transactions waiting for 854 * checkpointing. [j_list_lock] 855 */ 856 transaction_t *j_checkpoint_transactions; 857 858 /** 859 * @j_wait_transaction_locked: 860 * 861 * Wait queue for waiting for a locked transaction to start committing, 862 * or for a barrier lock to be released. 863 */ 864 wait_queue_head_t j_wait_transaction_locked; 865 866 /** 867 * @j_wait_done_commit: Wait queue for waiting for commit to complete. 868 */ 869 wait_queue_head_t j_wait_done_commit; 870 871 /** 872 * @j_wait_commit: Wait queue to trigger commit. 873 */ 874 wait_queue_head_t j_wait_commit; 875 876 /** 877 * @j_wait_updates: Wait queue to wait for updates to complete. 878 */ 879 wait_queue_head_t j_wait_updates; 880 881 /** 882 * @j_wait_reserved: 883 * 884 * Wait queue to wait for reserved buffer credits to drop. 885 */ 886 wait_queue_head_t j_wait_reserved; 887 888 /** 889 * @j_fc_wait: 890 * 891 * Wait queue to wait for completion of async fast commits. 892 */ 893 wait_queue_head_t j_fc_wait; 894 895 /** 896 * @j_checkpoint_mutex: 897 * 898 * Semaphore for locking against concurrent checkpoints. 899 */ 900 struct mutex j_checkpoint_mutex; 901 902 /** 903 * @j_chkpt_bhs: 904 * 905 * List of buffer heads used by the checkpoint routine. This 906 * was moved from jbd2_log_do_checkpoint() to reduce stack 907 * usage. Access to this array is controlled by the 908 * @j_checkpoint_mutex. [j_checkpoint_mutex] 909 */ 910 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 911 912 /** 913 * @j_shrinker: 914 * 915 * Journal head shrinker, reclaim buffer's journal head which 916 * has been written back. 917 */ 918 struct shrinker j_shrinker; 919 920 /** 921 * @j_checkpoint_jh_count: 922 * 923 * Number of journal buffers on the checkpoint list. [j_list_lock] 924 */ 925 struct percpu_counter j_checkpoint_jh_count; 926 927 /** 928 * @j_shrink_transaction: 929 * 930 * Record next transaction will shrink on the checkpoint list. 931 * [j_list_lock] 932 */ 933 transaction_t *j_shrink_transaction; 934 935 /** 936 * @j_head: 937 * 938 * Journal head: identifies the first unused block in the journal. 939 * [j_state_lock] 940 */ 941 unsigned long j_head; 942 943 /** 944 * @j_tail: 945 * 946 * Journal tail: identifies the oldest still-used block in the journal. 947 * [j_state_lock] 948 */ 949 unsigned long j_tail; 950 951 /** 952 * @j_free: 953 * 954 * Journal free: how many free blocks are there in the journal? 955 * [j_state_lock] 956 */ 957 unsigned long j_free; 958 959 /** 960 * @j_first: 961 * 962 * The block number of the first usable block in the journal 963 * [j_state_lock]. 964 */ 965 unsigned long j_first; 966 967 /** 968 * @j_last: 969 * 970 * The block number one beyond the last usable block in the journal 971 * [j_state_lock]. 972 */ 973 unsigned long j_last; 974 975 /** 976 * @j_fc_first: 977 * 978 * The block number of the first fast commit block in the journal 979 * [j_state_lock]. 980 */ 981 unsigned long j_fc_first; 982 983 /** 984 * @j_fc_off: 985 * 986 * Number of fast commit blocks currently allocated. Accessed only 987 * during fast commit. Currently only process can do fast commit, so 988 * this field is not protected by any lock. 989 */ 990 unsigned long j_fc_off; 991 992 /** 993 * @j_fc_last: 994 * 995 * The block number one beyond the last fast commit block in the journal 996 * [j_state_lock]. 997 */ 998 unsigned long j_fc_last; 999 1000 /** 1001 * @j_dev: Device where we store the journal. 1002 */ 1003 struct block_device *j_dev; 1004 1005 /** 1006 * @j_blocksize: Block size for the location where we store the journal. 1007 */ 1008 int j_blocksize; 1009 1010 /** 1011 * @j_blk_offset: 1012 * 1013 * Starting block offset into the device where we store the journal. 1014 */ 1015 unsigned long long j_blk_offset; 1016 1017 /** 1018 * @j_devname: Journal device name. 1019 */ 1020 char j_devname[BDEVNAME_SIZE+24]; 1021 1022 /** 1023 * @j_fs_dev: 1024 * 1025 * Device which holds the client fs. For internal journal this will be 1026 * equal to j_dev. 1027 */ 1028 struct block_device *j_fs_dev; 1029 1030 /** 1031 * @j_total_len: Total maximum capacity of the journal region on disk. 1032 */ 1033 unsigned int j_total_len; 1034 1035 /** 1036 * @j_reserved_credits: 1037 * 1038 * Number of buffers reserved from the running transaction. 1039 */ 1040 atomic_t j_reserved_credits; 1041 1042 /** 1043 * @j_list_lock: Protects the buffer lists and internal buffer state. 1044 */ 1045 spinlock_t j_list_lock; 1046 1047 /** 1048 * @j_inode: 1049 * 1050 * Optional inode where we store the journal. If present, all 1051 * journal block numbers are mapped into this inode via bmap(). 1052 */ 1053 struct inode *j_inode; 1054 1055 /** 1056 * @j_tail_sequence: 1057 * 1058 * Sequence number of the oldest transaction in the log [j_state_lock] 1059 */ 1060 tid_t j_tail_sequence; 1061 1062 /** 1063 * @j_transaction_sequence: 1064 * 1065 * Sequence number of the next transaction to grant [j_state_lock] 1066 */ 1067 tid_t j_transaction_sequence; 1068 1069 /** 1070 * @j_commit_sequence: 1071 * 1072 * Sequence number of the most recently committed transaction 1073 * [j_state_lock, no lock for quick racy checks] 1074 */ 1075 tid_t j_commit_sequence; 1076 1077 /** 1078 * @j_commit_request: 1079 * 1080 * Sequence number of the most recent transaction wanting commit 1081 * [j_state_lock, no lock for quick racy checks] 1082 */ 1083 tid_t j_commit_request; 1084 1085 /** 1086 * @j_uuid: 1087 * 1088 * Journal uuid: identifies the object (filesystem, LVM volume etc) 1089 * backed by this journal. This will eventually be replaced by an array 1090 * of uuids, allowing us to index multiple devices within a single 1091 * journal and to perform atomic updates across them. 1092 */ 1093 __u8 j_uuid[16]; 1094 1095 /** 1096 * @j_task: Pointer to the current commit thread for this journal. 1097 */ 1098 struct task_struct *j_task; 1099 1100 /** 1101 * @j_max_transaction_buffers: 1102 * 1103 * Maximum number of metadata buffers to allow in a single compound 1104 * commit transaction. 1105 */ 1106 int j_max_transaction_buffers; 1107 1108 /** 1109 * @j_revoke_records_per_block: 1110 * 1111 * Number of revoke records that fit in one descriptor block. 1112 */ 1113 int j_revoke_records_per_block; 1114 1115 /** 1116 * @j_commit_interval: 1117 * 1118 * What is the maximum transaction lifetime before we begin a commit? 1119 */ 1120 unsigned long j_commit_interval; 1121 1122 /** 1123 * @j_commit_timer: The timer used to wakeup the commit thread. 1124 */ 1125 struct timer_list j_commit_timer; 1126 1127 /** 1128 * @j_revoke_lock: Protect the revoke table. 1129 */ 1130 spinlock_t j_revoke_lock; 1131 1132 /** 1133 * @j_revoke: 1134 * 1135 * The revoke table - maintains the list of revoked blocks in the 1136 * current transaction. 1137 */ 1138 struct jbd2_revoke_table_s *j_revoke; 1139 1140 /** 1141 * @j_revoke_table: Alternate revoke tables for j_revoke. 1142 */ 1143 struct jbd2_revoke_table_s *j_revoke_table[2]; 1144 1145 /** 1146 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction. 1147 */ 1148 struct buffer_head **j_wbuf; 1149 1150 /** 1151 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only 1152 * during a fast commit. Currently only process can do fast commit, so 1153 * this field is not protected by any lock. 1154 */ 1155 struct buffer_head **j_fc_wbuf; 1156 1157 /** 1158 * @j_wbufsize: 1159 * 1160 * Size of @j_wbuf array. 1161 */ 1162 int j_wbufsize; 1163 1164 /** 1165 * @j_fc_wbufsize: 1166 * 1167 * Size of @j_fc_wbuf array. 1168 */ 1169 int j_fc_wbufsize; 1170 1171 /** 1172 * @j_last_sync_writer: 1173 * 1174 * The pid of the last person to run a synchronous operation 1175 * through the journal. 1176 */ 1177 pid_t j_last_sync_writer; 1178 1179 /** 1180 * @j_average_commit_time: 1181 * 1182 * The average amount of time in nanoseconds it takes to commit a 1183 * transaction to disk. [j_state_lock] 1184 */ 1185 u64 j_average_commit_time; 1186 1187 /** 1188 * @j_min_batch_time: 1189 * 1190 * Minimum time that we should wait for additional filesystem operations 1191 * to get batched into a synchronous handle in microseconds. 1192 */ 1193 u32 j_min_batch_time; 1194 1195 /** 1196 * @j_max_batch_time: 1197 * 1198 * Maximum time that we should wait for additional filesystem operations 1199 * to get batched into a synchronous handle in microseconds. 1200 */ 1201 u32 j_max_batch_time; 1202 1203 /** 1204 * @j_commit_callback: 1205 * 1206 * This function is called when a transaction is closed. 1207 */ 1208 void (*j_commit_callback)(journal_t *, 1209 transaction_t *); 1210 1211 /** 1212 * @j_submit_inode_data_buffers: 1213 * 1214 * This function is called for all inodes associated with the 1215 * committing transaction marked with JI_WRITE_DATA flag 1216 * before we start to write out the transaction to the journal. 1217 */ 1218 int (*j_submit_inode_data_buffers) 1219 (struct jbd2_inode *); 1220 1221 /** 1222 * @j_finish_inode_data_buffers: 1223 * 1224 * This function is called for all inodes associated with the 1225 * committing transaction marked with JI_WAIT_DATA flag 1226 * after we have written the transaction to the journal 1227 * but before we write out the commit block. 1228 */ 1229 int (*j_finish_inode_data_buffers) 1230 (struct jbd2_inode *); 1231 1232 /* 1233 * Journal statistics 1234 */ 1235 1236 /** 1237 * @j_history_lock: Protect the transactions statistics history. 1238 */ 1239 spinlock_t j_history_lock; 1240 1241 /** 1242 * @j_proc_entry: procfs entry for the jbd statistics directory. 1243 */ 1244 struct proc_dir_entry *j_proc_entry; 1245 1246 /** 1247 * @j_stats: Overall statistics. 1248 */ 1249 struct transaction_stats_s j_stats; 1250 1251 /** 1252 * @j_failed_commit: Failed journal commit ID. 1253 */ 1254 unsigned int j_failed_commit; 1255 1256 /** 1257 * @j_private: 1258 * 1259 * An opaque pointer to fs-private information. ext3 puts its 1260 * superblock pointer here. 1261 */ 1262 void *j_private; 1263 1264 /** 1265 * @j_chksum_driver: 1266 * 1267 * Reference to checksum algorithm driver via cryptoapi. 1268 */ 1269 struct crypto_shash *j_chksum_driver; 1270 1271 /** 1272 * @j_csum_seed: 1273 * 1274 * Precomputed journal UUID checksum for seeding other checksums. 1275 */ 1276 __u32 j_csum_seed; 1277 1278 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1279 /** 1280 * @j_trans_commit_map: 1281 * 1282 * Lockdep entity to track transaction commit dependencies. Handles 1283 * hold this "lock" for read, when we wait for commit, we acquire the 1284 * "lock" for writing. This matches the properties of jbd2 journalling 1285 * where the running transaction has to wait for all handles to be 1286 * dropped to commit that transaction and also acquiring a handle may 1287 * require transaction commit to finish. 1288 */ 1289 struct lockdep_map j_trans_commit_map; 1290 #endif 1291 1292 /** 1293 * @j_fc_cleanup_callback: 1294 * 1295 * Clean-up after fast commit or full commit. JBD2 calls this function 1296 * after every commit operation. 1297 */ 1298 void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid); 1299 1300 /** 1301 * @j_fc_replay_callback: 1302 * 1303 * File-system specific function that performs replay of a fast 1304 * commit. JBD2 calls this function for each fast commit block found in 1305 * the journal. This function should return JBD2_FC_REPLAY_CONTINUE 1306 * to indicate that the block was processed correctly and more fast 1307 * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP 1308 * indicates the end of replay (no more blocks remaining). A negative 1309 * return value indicates error. 1310 */ 1311 int (*j_fc_replay_callback)(struct journal_s *journal, 1312 struct buffer_head *bh, 1313 enum passtype pass, int off, 1314 tid_t expected_commit_id); 1315 }; 1316 1317 #define jbd2_might_wait_for_commit(j) \ 1318 do { \ 1319 rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \ 1320 rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \ 1321 } while (0) 1322 1323 /* journal feature predicate functions */ 1324 #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \ 1325 static inline bool jbd2_has_feature_##name(journal_t *j) \ 1326 { \ 1327 return ((j)->j_format_version >= 2 && \ 1328 ((j)->j_superblock->s_feature_compat & \ 1329 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \ 1330 } \ 1331 static inline void jbd2_set_feature_##name(journal_t *j) \ 1332 { \ 1333 (j)->j_superblock->s_feature_compat |= \ 1334 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \ 1335 } \ 1336 static inline void jbd2_clear_feature_##name(journal_t *j) \ 1337 { \ 1338 (j)->j_superblock->s_feature_compat &= \ 1339 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \ 1340 } 1341 1342 #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \ 1343 static inline bool jbd2_has_feature_##name(journal_t *j) \ 1344 { \ 1345 return ((j)->j_format_version >= 2 && \ 1346 ((j)->j_superblock->s_feature_ro_compat & \ 1347 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \ 1348 } \ 1349 static inline void jbd2_set_feature_##name(journal_t *j) \ 1350 { \ 1351 (j)->j_superblock->s_feature_ro_compat |= \ 1352 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \ 1353 } \ 1354 static inline void jbd2_clear_feature_##name(journal_t *j) \ 1355 { \ 1356 (j)->j_superblock->s_feature_ro_compat &= \ 1357 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \ 1358 } 1359 1360 #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \ 1361 static inline bool jbd2_has_feature_##name(journal_t *j) \ 1362 { \ 1363 return ((j)->j_format_version >= 2 && \ 1364 ((j)->j_superblock->s_feature_incompat & \ 1365 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \ 1366 } \ 1367 static inline void jbd2_set_feature_##name(journal_t *j) \ 1368 { \ 1369 (j)->j_superblock->s_feature_incompat |= \ 1370 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \ 1371 } \ 1372 static inline void jbd2_clear_feature_##name(journal_t *j) \ 1373 { \ 1374 (j)->j_superblock->s_feature_incompat &= \ 1375 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \ 1376 } 1377 1378 JBD2_FEATURE_COMPAT_FUNCS(checksum, CHECKSUM) 1379 1380 JBD2_FEATURE_INCOMPAT_FUNCS(revoke, REVOKE) 1381 JBD2_FEATURE_INCOMPAT_FUNCS(64bit, 64BIT) 1382 JBD2_FEATURE_INCOMPAT_FUNCS(async_commit, ASYNC_COMMIT) 1383 JBD2_FEATURE_INCOMPAT_FUNCS(csum2, CSUM_V2) 1384 JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3) 1385 JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT) 1386 1387 /* 1388 * Journal flag definitions 1389 */ 1390 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 1391 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 1392 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 1393 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 1394 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 1395 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 1396 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 1397 * data write error in ordered 1398 * mode */ 1399 #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */ 1400 #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */ 1401 #define JBD2_JOURNAL_FLUSH_DISCARD 0x0001 1402 #define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002 1403 #define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \ 1404 JBD2_JOURNAL_FLUSH_ZEROOUT) 1405 1406 /* 1407 * Journal atomic flag definitions 1408 */ 1409 #define JBD2_CHECKPOINT_IO_ERROR 0x001 /* Detect io error while writing 1410 * buffer back to disk */ 1411 1412 /* 1413 * Function declarations for the journaling transaction and buffer 1414 * management 1415 */ 1416 1417 /* Filing buffers */ 1418 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 1419 extern bool __jbd2_journal_refile_buffer(struct journal_head *); 1420 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 1421 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1422 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1423 static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh) 1424 { 1425 list_add_tail(&bh->b_assoc_buffers, head); 1426 } 1427 static inline void jbd2_unfile_log_bh(struct buffer_head *bh) 1428 { 1429 list_del_init(&bh->b_assoc_buffers); 1430 } 1431 1432 /* Log buffer allocation */ 1433 struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int); 1434 void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *); 1435 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 1436 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 1437 unsigned long *block); 1438 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1439 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1440 1441 /* Commit management */ 1442 extern void jbd2_journal_commit_transaction(journal_t *); 1443 1444 /* Checkpoint list management */ 1445 void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy); 1446 unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan); 1447 int __jbd2_journal_remove_checkpoint(struct journal_head *); 1448 void jbd2_journal_destroy_checkpoint(journal_t *journal); 1449 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1450 1451 1452 /* 1453 * Triggers 1454 */ 1455 1456 struct jbd2_buffer_trigger_type { 1457 /* 1458 * Fired a the moment data to write to the journal are known to be 1459 * stable - so either at the moment b_frozen_data is created or just 1460 * before a buffer is written to the journal. mapped_data is a mapped 1461 * buffer that is the frozen data for commit. 1462 */ 1463 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 1464 struct buffer_head *bh, void *mapped_data, 1465 size_t size); 1466 1467 /* 1468 * Fired during journal abort for dirty buffers that will not be 1469 * committed. 1470 */ 1471 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1472 struct buffer_head *bh); 1473 }; 1474 1475 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1476 void *mapped_data, 1477 struct jbd2_buffer_trigger_type *triggers); 1478 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1479 struct jbd2_buffer_trigger_type *triggers); 1480 1481 /* Buffer IO */ 1482 extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1483 struct journal_head *jh_in, 1484 struct buffer_head **bh_out, 1485 sector_t blocknr); 1486 1487 /* Transaction cache support */ 1488 extern void jbd2_journal_destroy_transaction_cache(void); 1489 extern int __init jbd2_journal_init_transaction_cache(void); 1490 extern void jbd2_journal_free_transaction(transaction_t *); 1491 1492 /* 1493 * Journal locking. 1494 * 1495 * We need to lock the journal during transaction state changes so that nobody 1496 * ever tries to take a handle on the running transaction while we are in the 1497 * middle of moving it to the commit phase. j_state_lock does this. 1498 * 1499 * Note that the locking is completely interrupt unsafe. We never touch 1500 * journal structures from interrupts. 1501 */ 1502 1503 static inline handle_t *journal_current_handle(void) 1504 { 1505 return current->journal_info; 1506 } 1507 1508 /* The journaling code user interface: 1509 * 1510 * Create and destroy handles 1511 * Register buffer modifications against the current transaction. 1512 */ 1513 1514 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1515 extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks, 1516 int revoke_records, gfp_t gfp_mask, 1517 unsigned int type, unsigned int line_no); 1518 extern int jbd2_journal_restart(handle_t *, int nblocks); 1519 extern int jbd2__journal_restart(handle_t *, int nblocks, 1520 int revoke_records, gfp_t gfp_mask); 1521 extern int jbd2_journal_start_reserved(handle_t *handle, 1522 unsigned int type, unsigned int line_no); 1523 extern void jbd2_journal_free_reserved(handle_t *handle); 1524 extern int jbd2_journal_extend(handle_t *handle, int nblocks, 1525 int revoke_records); 1526 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1527 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1528 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1529 void jbd2_journal_set_triggers(struct buffer_head *, 1530 struct jbd2_buffer_trigger_type *type); 1531 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1532 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1533 extern int jbd2_journal_invalidatepage(journal_t *, 1534 struct page *, unsigned int, unsigned int); 1535 extern int jbd2_journal_try_to_free_buffers(journal_t *journal, struct page *page); 1536 extern int jbd2_journal_stop(handle_t *); 1537 extern int jbd2_journal_flush(journal_t *journal, unsigned int flags); 1538 extern void jbd2_journal_lock_updates (journal_t *); 1539 extern void jbd2_journal_unlock_updates (journal_t *); 1540 1541 void jbd2_journal_wait_updates(journal_t *); 1542 1543 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1544 struct block_device *fs_dev, 1545 unsigned long long start, int len, int bsize); 1546 extern journal_t * jbd2_journal_init_inode (struct inode *); 1547 extern int jbd2_journal_update_format (journal_t *); 1548 extern int jbd2_journal_check_used_features 1549 (journal_t *, unsigned long, unsigned long, unsigned long); 1550 extern int jbd2_journal_check_available_features 1551 (journal_t *, unsigned long, unsigned long, unsigned long); 1552 extern int jbd2_journal_set_features 1553 (journal_t *, unsigned long, unsigned long, unsigned long); 1554 extern void jbd2_journal_clear_features 1555 (journal_t *, unsigned long, unsigned long, unsigned long); 1556 extern int jbd2_journal_load (journal_t *journal); 1557 extern int jbd2_journal_destroy (journal_t *); 1558 extern int jbd2_journal_recover (journal_t *journal); 1559 extern int jbd2_journal_wipe (journal_t *, int); 1560 extern int jbd2_journal_skip_recovery (journal_t *); 1561 extern void jbd2_journal_update_sb_errno(journal_t *); 1562 extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t, 1563 unsigned long, int); 1564 extern void jbd2_journal_abort (journal_t *, int); 1565 extern int jbd2_journal_errno (journal_t *); 1566 extern void jbd2_journal_ack_err (journal_t *); 1567 extern int jbd2_journal_clear_err (journal_t *); 1568 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1569 extern int jbd2_journal_force_commit(journal_t *); 1570 extern int jbd2_journal_force_commit_nested(journal_t *); 1571 extern int jbd2_journal_inode_ranged_write(handle_t *handle, 1572 struct jbd2_inode *inode, loff_t start_byte, 1573 loff_t length); 1574 extern int jbd2_journal_inode_ranged_wait(handle_t *handle, 1575 struct jbd2_inode *inode, loff_t start_byte, 1576 loff_t length); 1577 extern int jbd2_journal_submit_inode_data_buffers( 1578 struct jbd2_inode *jinode); 1579 extern int jbd2_journal_finish_inode_data_buffers( 1580 struct jbd2_inode *jinode); 1581 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1582 struct jbd2_inode *inode, loff_t new_size); 1583 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1584 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1585 1586 /* 1587 * journal_head management 1588 */ 1589 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1590 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1591 void jbd2_journal_put_journal_head(struct journal_head *jh); 1592 1593 /* 1594 * handle management 1595 */ 1596 extern struct kmem_cache *jbd2_handle_cache; 1597 1598 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1599 { 1600 return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags); 1601 } 1602 1603 static inline void jbd2_free_handle(handle_t *handle) 1604 { 1605 kmem_cache_free(jbd2_handle_cache, handle); 1606 } 1607 1608 /* 1609 * jbd2_inode management (optional, for those file systems that want to use 1610 * dynamically allocated jbd2_inode structures) 1611 */ 1612 extern struct kmem_cache *jbd2_inode_cache; 1613 1614 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1615 { 1616 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1617 } 1618 1619 static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1620 { 1621 kmem_cache_free(jbd2_inode_cache, jinode); 1622 } 1623 1624 /* Primary revoke support */ 1625 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1626 extern int jbd2_journal_init_revoke(journal_t *, int); 1627 extern void jbd2_journal_destroy_revoke_record_cache(void); 1628 extern void jbd2_journal_destroy_revoke_table_cache(void); 1629 extern int __init jbd2_journal_init_revoke_record_cache(void); 1630 extern int __init jbd2_journal_init_revoke_table_cache(void); 1631 1632 extern void jbd2_journal_destroy_revoke(journal_t *); 1633 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1634 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1635 extern void jbd2_journal_write_revoke_records(transaction_t *transaction, 1636 struct list_head *log_bufs); 1637 1638 /* Recovery revoke support */ 1639 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1640 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1641 extern void jbd2_journal_clear_revoke(journal_t *); 1642 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1643 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1644 1645 /* 1646 * The log thread user interface: 1647 * 1648 * Request space in the current transaction, and force transaction commit 1649 * transitions on demand. 1650 */ 1651 1652 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1653 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1654 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1655 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1656 int jbd2_transaction_committed(journal_t *journal, tid_t tid); 1657 int jbd2_complete_transaction(journal_t *journal, tid_t tid); 1658 int jbd2_log_do_checkpoint(journal_t *journal); 1659 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 1660 1661 void __jbd2_log_wait_for_space(journal_t *journal); 1662 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1663 extern int jbd2_cleanup_journal_tail(journal_t *); 1664 1665 /* Fast commit related APIs */ 1666 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid); 1667 int jbd2_fc_end_commit(journal_t *journal); 1668 int jbd2_fc_end_commit_fallback(journal_t *journal); 1669 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out); 1670 int jbd2_submit_inode_data(struct jbd2_inode *jinode); 1671 int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode); 1672 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks); 1673 int jbd2_fc_release_bufs(journal_t *journal); 1674 1675 static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal) 1676 { 1677 return (journal->j_total_len - journal->j_fc_wbufsize) / 4; 1678 } 1679 1680 /* 1681 * is_journal_abort 1682 * 1683 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1684 * bit, when set, indicates that we have had a fatal error somewhere, 1685 * either inside the journaling layer or indicated to us by the client 1686 * (eg. ext3), and that we and should not commit any further 1687 * transactions. 1688 */ 1689 1690 static inline int is_journal_aborted(journal_t *journal) 1691 { 1692 return journal->j_flags & JBD2_ABORT; 1693 } 1694 1695 static inline int is_handle_aborted(handle_t *handle) 1696 { 1697 if (handle->h_aborted || !handle->h_transaction) 1698 return 1; 1699 return is_journal_aborted(handle->h_transaction->t_journal); 1700 } 1701 1702 static inline void jbd2_journal_abort_handle(handle_t *handle) 1703 { 1704 handle->h_aborted = 1; 1705 } 1706 1707 #endif /* __KERNEL__ */ 1708 1709 /* Comparison functions for transaction IDs: perform comparisons using 1710 * modulo arithmetic so that they work over sequence number wraps. */ 1711 1712 static inline int tid_gt(tid_t x, tid_t y) 1713 { 1714 int difference = (x - y); 1715 return (difference > 0); 1716 } 1717 1718 static inline int tid_geq(tid_t x, tid_t y) 1719 { 1720 int difference = (x - y); 1721 return (difference >= 0); 1722 } 1723 1724 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1725 extern size_t journal_tag_bytes(journal_t *journal); 1726 1727 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j) 1728 { 1729 return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j); 1730 } 1731 1732 static inline int jbd2_journal_has_csum_v2or3(journal_t *journal) 1733 { 1734 WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) && 1735 journal->j_chksum_driver == NULL); 1736 1737 return journal->j_chksum_driver != NULL; 1738 } 1739 1740 static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb) 1741 { 1742 int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks); 1743 1744 return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS; 1745 } 1746 1747 /* 1748 * Return number of free blocks in the log. Must be called under j_state_lock. 1749 */ 1750 static inline unsigned long jbd2_log_space_left(journal_t *journal) 1751 { 1752 /* Allow for rounding errors */ 1753 long free = journal->j_free - 32; 1754 1755 if (journal->j_committing_transaction) { 1756 free -= atomic_read(&journal-> 1757 j_committing_transaction->t_outstanding_credits); 1758 } 1759 return max_t(long, free, 0); 1760 } 1761 1762 /* 1763 * Definitions which augment the buffer_head layer 1764 */ 1765 1766 /* journaling buffer types */ 1767 #define BJ_None 0 /* Not journaled */ 1768 #define BJ_Metadata 1 /* Normal journaled metadata */ 1769 #define BJ_Forget 2 /* Buffer superseded by this transaction */ 1770 #define BJ_Shadow 3 /* Buffer contents being shadowed to the log */ 1771 #define BJ_Reserved 4 /* Buffer is reserved for access by journal */ 1772 #define BJ_Types 5 1773 1774 /* JBD uses a CRC32 checksum */ 1775 #define JBD_MAX_CHECKSUM_SIZE 4 1776 1777 static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 1778 const void *address, unsigned int length) 1779 { 1780 struct { 1781 struct shash_desc shash; 1782 char ctx[JBD_MAX_CHECKSUM_SIZE]; 1783 } desc; 1784 int err; 1785 1786 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) > 1787 JBD_MAX_CHECKSUM_SIZE); 1788 1789 desc.shash.tfm = journal->j_chksum_driver; 1790 *(u32 *)desc.ctx = crc; 1791 1792 err = crypto_shash_update(&desc.shash, address, length); 1793 BUG_ON(err); 1794 1795 return *(u32 *)desc.ctx; 1796 } 1797 1798 /* Return most recent uncommitted transaction */ 1799 static inline tid_t jbd2_get_latest_transaction(journal_t *journal) 1800 { 1801 tid_t tid; 1802 1803 read_lock(&journal->j_state_lock); 1804 tid = journal->j_commit_request; 1805 if (journal->j_running_transaction) 1806 tid = journal->j_running_transaction->t_tid; 1807 read_unlock(&journal->j_state_lock); 1808 return tid; 1809 } 1810 1811 static inline int jbd2_handle_buffer_credits(handle_t *handle) 1812 { 1813 journal_t *journal; 1814 1815 if (!handle->h_reserved) 1816 journal = handle->h_transaction->t_journal; 1817 else 1818 journal = handle->h_journal; 1819 1820 return handle->h_total_credits - 1821 DIV_ROUND_UP(handle->h_revoke_credits_requested, 1822 journal->j_revoke_records_per_block); 1823 } 1824 1825 #ifdef __KERNEL__ 1826 1827 #define buffer_trace_init(bh) do {} while (0) 1828 #define print_buffer_fields(bh) do {} while (0) 1829 #define print_buffer_trace(bh) do {} while (0) 1830 #define BUFFER_TRACE(bh, info) do {} while (0) 1831 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1832 #define JBUFFER_TRACE(jh, info) do {} while (0) 1833 1834 #endif /* __KERNEL__ */ 1835 1836 #define EFSBADCRC EBADMSG /* Bad CRC detected */ 1837 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ 1838 1839 #endif /* _LINUX_JBD2_H */ 1840