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 #else 24 25 #include <linux/types.h> 26 #include <linux/buffer_head.h> 27 #include <linux/journal-head.h> 28 #include <linux/stddef.h> 29 #include <linux/bit_spinlock.h> 30 #include <linux/mutex.h> 31 #include <linux/timer.h> 32 #include <linux/slab.h> 33 #include <crypto/hash.h> 34 #endif 35 36 #define journal_oom_retry 1 37 38 /* 39 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 40 * certain classes of error which can occur due to failed IOs. Under 41 * normal use we want ext4 to continue after such errors, because 42 * hardware _can_ fail, but for debugging purposes when running tests on 43 * known-good hardware we may want to trap these errors. 44 */ 45 #undef JBD2_PARANOID_IOFAIL 46 47 /* 48 * The default maximum commit age, in seconds. 49 */ 50 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 51 52 #ifdef CONFIG_JBD2_DEBUG 53 /* 54 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 55 * consistency checks. By default we don't do this unless 56 * CONFIG_JBD2_DEBUG is on. 57 */ 58 #define JBD2_EXPENSIVE_CHECKING 59 extern ushort jbd2_journal_enable_debug; 60 61 #define jbd_debug(n, f, a...) \ 62 do { \ 63 if ((n) <= jbd2_journal_enable_debug) { \ 64 printk (KERN_DEBUG "(%s, %d): %s: ", \ 65 __FILE__, __LINE__, __func__); \ 66 printk (f, ## a); \ 67 } \ 68 } while (0) 69 #else 70 #define jbd_debug(f, a...) /**/ 71 #endif 72 73 extern void *jbd2_alloc(size_t size, gfp_t flags); 74 extern void jbd2_free(void *ptr, size_t size); 75 76 #define JBD2_MIN_JOURNAL_BLOCKS 1024 77 78 #ifdef __KERNEL__ 79 80 /** 81 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 82 * 83 * All filesystem modifications made by the process go 84 * through this handle. Recursive operations (such as quota operations) 85 * are gathered into a single update. 86 * 87 * The buffer credits field is used to account for journaled buffers 88 * being modified by the running process. To ensure that there is 89 * enough log space for all outstanding operations, we need to limit the 90 * number of outstanding buffers possible at any time. When the 91 * operation completes, any buffer credits not used are credited back to 92 * the transaction, so that at all times we know how many buffers the 93 * outstanding updates on a transaction might possibly touch. 94 * 95 * This is an opaque datatype. 96 **/ 97 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */ 98 99 100 /** 101 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 102 * 103 * journal_t is linked to from the fs superblock structure. 104 * 105 * We use the journal_t to keep track of all outstanding transaction 106 * activity on the filesystem, and to manage the state of the log 107 * writing process. 108 * 109 * This is an opaque datatype. 110 **/ 111 typedef struct journal_s journal_t; /* Journal control structure */ 112 #endif 113 114 /* 115 * Internal structures used by the logging mechanism: 116 */ 117 118 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 119 120 /* 121 * On-disk structures 122 */ 123 124 /* 125 * Descriptor block types: 126 */ 127 128 #define JBD2_DESCRIPTOR_BLOCK 1 129 #define JBD2_COMMIT_BLOCK 2 130 #define JBD2_SUPERBLOCK_V1 3 131 #define JBD2_SUPERBLOCK_V2 4 132 #define JBD2_REVOKE_BLOCK 5 133 134 /* 135 * Standard header for all descriptor blocks: 136 */ 137 typedef struct journal_header_s 138 { 139 __be32 h_magic; 140 __be32 h_blocktype; 141 __be32 h_sequence; 142 } journal_header_t; 143 144 /* 145 * Checksum types. 146 */ 147 #define JBD2_CRC32_CHKSUM 1 148 #define JBD2_MD5_CHKSUM 2 149 #define JBD2_SHA1_CHKSUM 3 150 #define JBD2_CRC32C_CHKSUM 4 151 152 #define JBD2_CRC32_CHKSUM_SIZE 4 153 154 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 155 /* 156 * Commit block header for storing transactional checksums: 157 * 158 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* 159 * fields are used to store a checksum of the descriptor and data blocks. 160 * 161 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum 162 * field is used to store crc32c(uuid+commit_block). Each journal metadata 163 * block gets its own checksum, and data block checksums are stored in 164 * journal_block_tag (in the descriptor). The other h_chksum* fields are 165 * not used. 166 * 167 * Checksum v1 and v2 are mutually exclusive features. 168 */ 169 struct commit_header { 170 __be32 h_magic; 171 __be32 h_blocktype; 172 __be32 h_sequence; 173 unsigned char h_chksum_type; 174 unsigned char h_chksum_size; 175 unsigned char h_padding[2]; 176 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 177 __be64 h_commit_sec; 178 __be32 h_commit_nsec; 179 }; 180 181 /* 182 * The block tag: used to describe a single buffer in the journal. 183 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 184 * raw struct shouldn't be used for pointer math or sizeof() - use 185 * journal_tag_bytes(journal) instead to compute this. 186 */ 187 typedef struct journal_block_tag_s 188 { 189 __be32 t_blocknr; /* The on-disk block number */ 190 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ 191 __be16 t_flags; /* See below */ 192 __be32 t_blocknr_high; /* most-significant high 32bits. */ 193 } journal_block_tag_t; 194 195 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 196 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 197 198 /* Tail of descriptor block, for checksumming */ 199 struct jbd2_journal_block_tail { 200 __be32 t_checksum; /* crc32c(uuid+descr_block) */ 201 }; 202 203 /* 204 * The revoke descriptor: used on disk to describe a series of blocks to 205 * be revoked from the log 206 */ 207 typedef struct jbd2_journal_revoke_header_s 208 { 209 journal_header_t r_header; 210 __be32 r_count; /* Count of bytes used in the block */ 211 } jbd2_journal_revoke_header_t; 212 213 /* Tail of revoke block, for checksumming */ 214 struct jbd2_journal_revoke_tail { 215 __be32 r_checksum; /* crc32c(uuid+revoke_block) */ 216 }; 217 218 /* Definitions for the journal tag flags word: */ 219 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 220 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 221 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 222 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 223 224 225 /* 226 * The journal superblock. All fields are in big-endian byte order. 227 */ 228 typedef struct journal_superblock_s 229 { 230 /* 0x0000 */ 231 journal_header_t s_header; 232 233 /* 0x000C */ 234 /* Static information describing the journal */ 235 __be32 s_blocksize; /* journal device blocksize */ 236 __be32 s_maxlen; /* total blocks in journal file */ 237 __be32 s_first; /* first block of log information */ 238 239 /* 0x0018 */ 240 /* Dynamic information describing the current state of the log */ 241 __be32 s_sequence; /* first commit ID expected in log */ 242 __be32 s_start; /* blocknr of start of log */ 243 244 /* 0x0020 */ 245 /* Error value, as set by jbd2_journal_abort(). */ 246 __be32 s_errno; 247 248 /* 0x0024 */ 249 /* Remaining fields are only valid in a version-2 superblock */ 250 __be32 s_feature_compat; /* compatible feature set */ 251 __be32 s_feature_incompat; /* incompatible feature set */ 252 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 253 /* 0x0030 */ 254 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 255 256 /* 0x0040 */ 257 __be32 s_nr_users; /* Nr of filesystems sharing log */ 258 259 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 260 261 /* 0x0048 */ 262 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 263 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 264 265 /* 0x0050 */ 266 __u8 s_checksum_type; /* checksum type */ 267 __u8 s_padding2[3]; 268 __u32 s_padding[42]; 269 __be32 s_checksum; /* crc32c(superblock) */ 270 271 /* 0x0100 */ 272 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 273 /* 0x0400 */ 274 } journal_superblock_t; 275 276 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 277 ((j)->j_format_version >= 2 && \ 278 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 279 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 280 ((j)->j_format_version >= 2 && \ 281 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 282 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 283 ((j)->j_format_version >= 2 && \ 284 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 285 286 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 287 288 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 289 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 290 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 291 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 292 293 /* Features known to this kernel version: */ 294 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 295 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 296 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 297 JBD2_FEATURE_INCOMPAT_64BIT | \ 298 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \ 299 JBD2_FEATURE_INCOMPAT_CSUM_V2) 300 301 #ifdef __KERNEL__ 302 303 #include <linux/fs.h> 304 #include <linux/sched.h> 305 #include <linux/jbd_common.h> 306 307 #define J_ASSERT(assert) BUG_ON(!(assert)) 308 309 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 310 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 311 312 #if defined(JBD2_PARANOID_IOFAIL) 313 #define J_EXPECT(expr, why...) J_ASSERT(expr) 314 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 315 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 316 #else 317 #define __journal_expect(expr, why...) \ 318 ({ \ 319 int val = (expr); \ 320 if (!val) { \ 321 printk(KERN_ERR \ 322 "JBD2 unexpected failure: %s: %s;\n", \ 323 __func__, #expr); \ 324 printk(KERN_ERR why "\n"); \ 325 } \ 326 val; \ 327 }) 328 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 329 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 330 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 331 #endif 332 333 /* Flags in jbd_inode->i_flags */ 334 #define __JI_COMMIT_RUNNING 0 335 /* Commit of the inode data in progress. We use this flag to protect us from 336 * concurrent deletion of inode. We cannot use reference to inode for this 337 * since we cannot afford doing last iput() on behalf of kjournald 338 */ 339 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 340 341 /** 342 * struct jbd_inode is the structure linking inodes in ordered mode 343 * present in a transaction so that we can sync them during commit. 344 */ 345 struct jbd2_inode { 346 /* Which transaction does this inode belong to? Either the running 347 * transaction or the committing one. [j_list_lock] */ 348 transaction_t *i_transaction; 349 350 /* Pointer to the running transaction modifying inode's data in case 351 * there is already a committing transaction touching it. [j_list_lock] */ 352 transaction_t *i_next_transaction; 353 354 /* List of inodes in the i_transaction [j_list_lock] */ 355 struct list_head i_list; 356 357 /* VFS inode this inode belongs to [constant during the lifetime 358 * of the structure] */ 359 struct inode *i_vfs_inode; 360 361 /* Flags of inode [j_list_lock] */ 362 unsigned long i_flags; 363 }; 364 365 struct jbd2_revoke_table_s; 366 367 /** 368 * struct handle_s - The handle_s type is the concrete type associated with 369 * handle_t. 370 * @h_transaction: Which compound transaction is this update a part of? 371 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 372 * @h_ref: Reference count on this handle 373 * @h_err: Field for caller's use to track errors through large fs operations 374 * @h_sync: flag for sync-on-close 375 * @h_jdata: flag to force data journaling 376 * @h_aborted: flag indicating fatal error on handle 377 **/ 378 379 /* Docbook can't yet cope with the bit fields, but will leave the documentation 380 * in so it can be fixed later. 381 */ 382 383 struct jbd2_journal_handle 384 { 385 /* Which compound transaction is this update a part of? */ 386 transaction_t *h_transaction; 387 388 /* Number of remaining buffers we are allowed to dirty: */ 389 int h_buffer_credits; 390 391 /* Reference count on this handle */ 392 int h_ref; 393 394 /* Field for caller's use to track errors through large fs */ 395 /* operations */ 396 int h_err; 397 398 /* Flags [no locking] */ 399 unsigned int h_sync: 1; /* sync-on-close */ 400 unsigned int h_jdata: 1; /* force data journaling */ 401 unsigned int h_aborted: 1; /* fatal error on handle */ 402 unsigned int h_type: 8; /* for handle statistics */ 403 unsigned int h_line_no: 16; /* for handle statistics */ 404 405 unsigned long h_start_jiffies; 406 unsigned int h_requested_credits; 407 408 #ifdef CONFIG_DEBUG_LOCK_ALLOC 409 struct lockdep_map h_lockdep_map; 410 #endif 411 }; 412 413 414 /* 415 * Some stats for checkpoint phase 416 */ 417 struct transaction_chp_stats_s { 418 unsigned long cs_chp_time; 419 __u32 cs_forced_to_close; 420 __u32 cs_written; 421 __u32 cs_dropped; 422 }; 423 424 /* The transaction_t type is the guts of the journaling mechanism. It 425 * tracks a compound transaction through its various states: 426 * 427 * RUNNING: accepting new updates 428 * LOCKED: Updates still running but we don't accept new ones 429 * RUNDOWN: Updates are tidying up but have finished requesting 430 * new buffers to modify (state not used for now) 431 * FLUSH: All updates complete, but we are still writing to disk 432 * COMMIT: All data on disk, writing commit record 433 * FINISHED: We still have to keep the transaction for checkpointing. 434 * 435 * The transaction keeps track of all of the buffers modified by a 436 * running transaction, and all of the buffers committed but not yet 437 * flushed to home for finished transactions. 438 */ 439 440 /* 441 * Lock ranking: 442 * 443 * j_list_lock 444 * ->jbd_lock_bh_journal_head() (This is "innermost") 445 * 446 * j_state_lock 447 * ->jbd_lock_bh_state() 448 * 449 * jbd_lock_bh_state() 450 * ->j_list_lock 451 * 452 * j_state_lock 453 * ->t_handle_lock 454 * 455 * j_state_lock 456 * ->j_list_lock (journal_unmap_buffer) 457 * 458 */ 459 460 struct transaction_s 461 { 462 /* Pointer to the journal for this transaction. [no locking] */ 463 journal_t *t_journal; 464 465 /* Sequence number for this transaction [no locking] */ 466 tid_t t_tid; 467 468 /* 469 * Transaction's current state 470 * [no locking - only kjournald2 alters this] 471 * [j_list_lock] guards transition of a transaction into T_FINISHED 472 * state and subsequent call of __jbd2_journal_drop_transaction() 473 * FIXME: needs barriers 474 * KLUDGE: [use j_state_lock] 475 */ 476 enum { 477 T_RUNNING, 478 T_LOCKED, 479 T_FLUSH, 480 T_COMMIT, 481 T_COMMIT_DFLUSH, 482 T_COMMIT_JFLUSH, 483 T_COMMIT_CALLBACK, 484 T_FINISHED 485 } t_state; 486 487 /* 488 * Where in the log does this transaction's commit start? [no locking] 489 */ 490 unsigned long t_log_start; 491 492 /* Number of buffers on the t_buffers list [j_list_lock] */ 493 int t_nr_buffers; 494 495 /* 496 * Doubly-linked circular list of all buffers reserved but not yet 497 * modified by this transaction [j_list_lock] 498 */ 499 struct journal_head *t_reserved_list; 500 501 /* 502 * Doubly-linked circular list of all metadata buffers owned by this 503 * transaction [j_list_lock] 504 */ 505 struct journal_head *t_buffers; 506 507 /* 508 * Doubly-linked circular list of all forget buffers (superseded 509 * buffers which we can un-checkpoint once this transaction commits) 510 * [j_list_lock] 511 */ 512 struct journal_head *t_forget; 513 514 /* 515 * Doubly-linked circular list of all buffers still to be flushed before 516 * this transaction can be checkpointed. [j_list_lock] 517 */ 518 struct journal_head *t_checkpoint_list; 519 520 /* 521 * Doubly-linked circular list of all buffers submitted for IO while 522 * checkpointing. [j_list_lock] 523 */ 524 struct journal_head *t_checkpoint_io_list; 525 526 /* 527 * Doubly-linked circular list of temporary buffers currently undergoing 528 * IO in the log [j_list_lock] 529 */ 530 struct journal_head *t_iobuf_list; 531 532 /* 533 * Doubly-linked circular list of metadata buffers being shadowed by log 534 * IO. The IO buffers on the iobuf list and the shadow buffers on this 535 * list match each other one for one at all times. [j_list_lock] 536 */ 537 struct journal_head *t_shadow_list; 538 539 /* 540 * Doubly-linked circular list of control buffers being written to the 541 * log. [j_list_lock] 542 */ 543 struct journal_head *t_log_list; 544 545 /* 546 * List of inodes whose data we've modified in data=ordered mode. 547 * [j_list_lock] 548 */ 549 struct list_head t_inode_list; 550 551 /* 552 * Protects info related to handles 553 */ 554 spinlock_t t_handle_lock; 555 556 /* 557 * Longest time some handle had to wait for running transaction 558 */ 559 unsigned long t_max_wait; 560 561 /* 562 * When transaction started 563 */ 564 unsigned long t_start; 565 566 /* 567 * When commit was requested 568 */ 569 unsigned long t_requested; 570 571 /* 572 * Checkpointing stats [j_checkpoint_sem] 573 */ 574 struct transaction_chp_stats_s t_chp_stats; 575 576 /* 577 * Number of outstanding updates running on this transaction 578 * [t_handle_lock] 579 */ 580 atomic_t t_updates; 581 582 /* 583 * Number of buffers reserved for use by all handles in this transaction 584 * handle but not yet modified. [t_handle_lock] 585 */ 586 atomic_t t_outstanding_credits; 587 588 /* 589 * Forward and backward links for the circular list of all transactions 590 * awaiting checkpoint. [j_list_lock] 591 */ 592 transaction_t *t_cpnext, *t_cpprev; 593 594 /* 595 * When will the transaction expire (become due for commit), in jiffies? 596 * [no locking] 597 */ 598 unsigned long t_expires; 599 600 /* 601 * When this transaction started, in nanoseconds [no locking] 602 */ 603 ktime_t t_start_time; 604 605 /* 606 * How many handles used this transaction? [t_handle_lock] 607 */ 608 atomic_t t_handle_count; 609 610 /* 611 * This transaction is being forced and some process is 612 * waiting for it to finish. 613 */ 614 unsigned int t_synchronous_commit:1; 615 616 /* Disk flush needs to be sent to fs partition [no locking] */ 617 int t_need_data_flush; 618 619 /* 620 * For use by the filesystem to store fs-specific data 621 * structures associated with the transaction 622 */ 623 struct list_head t_private_list; 624 }; 625 626 struct transaction_run_stats_s { 627 unsigned long rs_wait; 628 unsigned long rs_request_delay; 629 unsigned long rs_running; 630 unsigned long rs_locked; 631 unsigned long rs_flushing; 632 unsigned long rs_logging; 633 634 __u32 rs_handle_count; 635 __u32 rs_blocks; 636 __u32 rs_blocks_logged; 637 }; 638 639 struct transaction_stats_s { 640 unsigned long ts_tid; 641 unsigned long ts_requested; 642 struct transaction_run_stats_s run; 643 }; 644 645 static inline unsigned long 646 jbd2_time_diff(unsigned long start, unsigned long end) 647 { 648 if (end >= start) 649 return end - start; 650 651 return end + (MAX_JIFFY_OFFSET - start); 652 } 653 654 #define JBD2_NR_BATCH 64 655 656 /** 657 * struct journal_s - The journal_s type is the concrete type associated with 658 * journal_t. 659 * @j_flags: General journaling state flags 660 * @j_errno: Is there an outstanding uncleared error on the journal (from a 661 * prior abort)? 662 * @j_sb_buffer: First part of superblock buffer 663 * @j_superblock: Second part of superblock buffer 664 * @j_format_version: Version of the superblock format 665 * @j_state_lock: Protect the various scalars in the journal 666 * @j_barrier_count: Number of processes waiting to create a barrier lock 667 * @j_barrier: The barrier lock itself 668 * @j_running_transaction: The current running transaction.. 669 * @j_committing_transaction: the transaction we are pushing to disk 670 * @j_checkpoint_transactions: a linked circular list of all transactions 671 * waiting for checkpointing 672 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 673 * to start committing, or for a barrier lock to be released 674 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 675 * @j_wait_done_commit: Wait queue for waiting for commit to complete 676 * @j_wait_checkpoint: Wait queue to trigger checkpointing 677 * @j_wait_commit: Wait queue to trigger commit 678 * @j_wait_updates: Wait queue to wait for updates to complete 679 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 680 * @j_head: Journal head - identifies the first unused block in the journal 681 * @j_tail: Journal tail - identifies the oldest still-used block in the 682 * journal. 683 * @j_free: Journal free - how many free blocks are there in the journal? 684 * @j_first: The block number of the first usable block 685 * @j_last: The block number one beyond the last usable block 686 * @j_dev: Device where we store the journal 687 * @j_blocksize: blocksize for the location where we store the journal. 688 * @j_blk_offset: starting block offset for into the device where we store the 689 * journal 690 * @j_fs_dev: Device which holds the client fs. For internal journal this will 691 * be equal to j_dev 692 * @j_maxlen: Total maximum capacity of the journal region on disk. 693 * @j_list_lock: Protects the buffer lists and internal buffer state. 694 * @j_inode: Optional inode where we store the journal. If present, all journal 695 * block numbers are mapped into this inode via bmap(). 696 * @j_tail_sequence: Sequence number of the oldest transaction in the log 697 * @j_transaction_sequence: Sequence number of the next transaction to grant 698 * @j_commit_sequence: Sequence number of the most recently committed 699 * transaction 700 * @j_commit_request: Sequence number of the most recent transaction wanting 701 * commit 702 * @j_uuid: Uuid of client object. 703 * @j_task: Pointer to the current commit thread for this journal 704 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 705 * single compound commit transaction 706 * @j_commit_interval: What is the maximum transaction lifetime before we begin 707 * a commit? 708 * @j_commit_timer: The timer used to wakeup the commit thread 709 * @j_revoke_lock: Protect the revoke table 710 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 711 * current transaction. 712 * @j_revoke_table: alternate revoke tables for j_revoke 713 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 714 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 715 * number that will fit in j_blocksize 716 * @j_last_sync_writer: most recent pid which did a synchronous write 717 * @j_history: Buffer storing the transactions statistics history 718 * @j_history_max: Maximum number of transactions in the statistics history 719 * @j_history_cur: Current number of transactions in the statistics history 720 * @j_history_lock: Protect the transactions statistics history 721 * @j_proc_entry: procfs entry for the jbd statistics directory 722 * @j_stats: Overall statistics 723 * @j_private: An opaque pointer to fs-private information. 724 */ 725 726 struct journal_s 727 { 728 /* General journaling state flags [j_state_lock] */ 729 unsigned long j_flags; 730 731 /* 732 * Is there an outstanding uncleared error on the journal (from a prior 733 * abort)? [j_state_lock] 734 */ 735 int j_errno; 736 737 /* The superblock buffer */ 738 struct buffer_head *j_sb_buffer; 739 journal_superblock_t *j_superblock; 740 741 /* Version of the superblock format */ 742 int j_format_version; 743 744 /* 745 * Protect the various scalars in the journal 746 */ 747 rwlock_t j_state_lock; 748 749 /* 750 * Number of processes waiting to create a barrier lock [j_state_lock] 751 */ 752 int j_barrier_count; 753 754 /* The barrier lock itself */ 755 struct mutex j_barrier; 756 757 /* 758 * Transactions: The current running transaction... 759 * [j_state_lock] [caller holding open handle] 760 */ 761 transaction_t *j_running_transaction; 762 763 /* 764 * the transaction we are pushing to disk 765 * [j_state_lock] [caller holding open handle] 766 */ 767 transaction_t *j_committing_transaction; 768 769 /* 770 * ... and a linked circular list of all transactions waiting for 771 * checkpointing. [j_list_lock] 772 */ 773 transaction_t *j_checkpoint_transactions; 774 775 /* 776 * Wait queue for waiting for a locked transaction to start committing, 777 * or for a barrier lock to be released 778 */ 779 wait_queue_head_t j_wait_transaction_locked; 780 781 /* Wait queue for waiting for checkpointing to complete */ 782 wait_queue_head_t j_wait_logspace; 783 784 /* Wait queue for waiting for commit to complete */ 785 wait_queue_head_t j_wait_done_commit; 786 787 /* Wait queue to trigger checkpointing */ 788 wait_queue_head_t j_wait_checkpoint; 789 790 /* Wait queue to trigger commit */ 791 wait_queue_head_t j_wait_commit; 792 793 /* Wait queue to wait for updates to complete */ 794 wait_queue_head_t j_wait_updates; 795 796 /* Semaphore for locking against concurrent checkpoints */ 797 struct mutex j_checkpoint_mutex; 798 799 /* 800 * List of buffer heads used by the checkpoint routine. This 801 * was moved from jbd2_log_do_checkpoint() to reduce stack 802 * usage. Access to this array is controlled by the 803 * j_checkpoint_mutex. [j_checkpoint_mutex] 804 */ 805 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 806 807 /* 808 * Journal head: identifies the first unused block in the journal. 809 * [j_state_lock] 810 */ 811 unsigned long j_head; 812 813 /* 814 * Journal tail: identifies the oldest still-used block in the journal. 815 * [j_state_lock] 816 */ 817 unsigned long j_tail; 818 819 /* 820 * Journal free: how many free blocks are there in the journal? 821 * [j_state_lock] 822 */ 823 unsigned long j_free; 824 825 /* 826 * Journal start and end: the block numbers of the first usable block 827 * and one beyond the last usable block in the journal. [j_state_lock] 828 */ 829 unsigned long j_first; 830 unsigned long j_last; 831 832 /* 833 * Device, blocksize and starting block offset for the location where we 834 * store the journal. 835 */ 836 struct block_device *j_dev; 837 int j_blocksize; 838 unsigned long long j_blk_offset; 839 char j_devname[BDEVNAME_SIZE+24]; 840 841 /* 842 * Device which holds the client fs. For internal journal this will be 843 * equal to j_dev. 844 */ 845 struct block_device *j_fs_dev; 846 847 /* Total maximum capacity of the journal region on disk. */ 848 unsigned int j_maxlen; 849 850 /* 851 * Protects the buffer lists and internal buffer state. 852 */ 853 spinlock_t j_list_lock; 854 855 /* Optional inode where we store the journal. If present, all */ 856 /* journal block numbers are mapped into this inode via */ 857 /* bmap(). */ 858 struct inode *j_inode; 859 860 /* 861 * Sequence number of the oldest transaction in the log [j_state_lock] 862 */ 863 tid_t j_tail_sequence; 864 865 /* 866 * Sequence number of the next transaction to grant [j_state_lock] 867 */ 868 tid_t j_transaction_sequence; 869 870 /* 871 * Sequence number of the most recently committed transaction 872 * [j_state_lock]. 873 */ 874 tid_t j_commit_sequence; 875 876 /* 877 * Sequence number of the most recent transaction wanting commit 878 * [j_state_lock] 879 */ 880 tid_t j_commit_request; 881 882 /* 883 * Journal uuid: identifies the object (filesystem, LVM volume etc) 884 * backed by this journal. This will eventually be replaced by an array 885 * of uuids, allowing us to index multiple devices within a single 886 * journal and to perform atomic updates across them. 887 */ 888 __u8 j_uuid[16]; 889 890 /* Pointer to the current commit thread for this journal */ 891 struct task_struct *j_task; 892 893 /* 894 * Maximum number of metadata buffers to allow in a single compound 895 * commit transaction 896 */ 897 int j_max_transaction_buffers; 898 899 /* 900 * What is the maximum transaction lifetime before we begin a commit? 901 */ 902 unsigned long j_commit_interval; 903 904 /* The timer used to wakeup the commit thread: */ 905 struct timer_list j_commit_timer; 906 907 /* 908 * The revoke table: maintains the list of revoked blocks in the 909 * current transaction. [j_revoke_lock] 910 */ 911 spinlock_t j_revoke_lock; 912 struct jbd2_revoke_table_s *j_revoke; 913 struct jbd2_revoke_table_s *j_revoke_table[2]; 914 915 /* 916 * array of bhs for jbd2_journal_commit_transaction 917 */ 918 struct buffer_head **j_wbuf; 919 int j_wbufsize; 920 921 /* 922 * this is the pid of hte last person to run a synchronous operation 923 * through the journal 924 */ 925 pid_t j_last_sync_writer; 926 927 /* 928 * the average amount of time in nanoseconds it takes to commit a 929 * transaction to disk. [j_state_lock] 930 */ 931 u64 j_average_commit_time; 932 933 /* 934 * minimum and maximum times that we should wait for 935 * additional filesystem operations to get batched into a 936 * synchronous handle in microseconds 937 */ 938 u32 j_min_batch_time; 939 u32 j_max_batch_time; 940 941 /* This function is called when a transaction is closed */ 942 void (*j_commit_callback)(journal_t *, 943 transaction_t *); 944 945 /* 946 * Journal statistics 947 */ 948 spinlock_t j_history_lock; 949 struct proc_dir_entry *j_proc_entry; 950 struct transaction_stats_s j_stats; 951 952 /* Failed journal commit ID */ 953 unsigned int j_failed_commit; 954 955 /* 956 * An opaque pointer to fs-private information. ext3 puts its 957 * superblock pointer here 958 */ 959 void *j_private; 960 961 /* Reference to checksum algorithm driver via cryptoapi */ 962 struct crypto_shash *j_chksum_driver; 963 964 /* Precomputed journal UUID checksum for seeding other checksums */ 965 __u32 j_csum_seed; 966 }; 967 968 /* 969 * Journal flag definitions 970 */ 971 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 972 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 973 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 974 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 975 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 976 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 977 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 978 * data write error in ordered 979 * mode */ 980 981 /* 982 * Function declarations for the journaling transaction and buffer 983 * management 984 */ 985 986 /* Filing buffers */ 987 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 988 extern void __jbd2_journal_refile_buffer(struct journal_head *); 989 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 990 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 991 extern void __journal_free_buffer(struct journal_head *bh); 992 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 993 extern void __journal_clean_data_list(transaction_t *transaction); 994 995 /* Log buffer allocation */ 996 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 997 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 998 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 999 unsigned long *block); 1000 void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1001 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1002 1003 /* Commit management */ 1004 extern void jbd2_journal_commit_transaction(journal_t *); 1005 1006 /* Checkpoint list management */ 1007 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 1008 int __jbd2_journal_remove_checkpoint(struct journal_head *); 1009 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1010 1011 1012 /* 1013 * Triggers 1014 */ 1015 1016 struct jbd2_buffer_trigger_type { 1017 /* 1018 * Fired a the moment data to write to the journal are known to be 1019 * stable - so either at the moment b_frozen_data is created or just 1020 * before a buffer is written to the journal. mapped_data is a mapped 1021 * buffer that is the frozen data for commit. 1022 */ 1023 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 1024 struct buffer_head *bh, void *mapped_data, 1025 size_t size); 1026 1027 /* 1028 * Fired during journal abort for dirty buffers that will not be 1029 * committed. 1030 */ 1031 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1032 struct buffer_head *bh); 1033 }; 1034 1035 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1036 void *mapped_data, 1037 struct jbd2_buffer_trigger_type *triggers); 1038 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1039 struct jbd2_buffer_trigger_type *triggers); 1040 1041 /* Buffer IO */ 1042 extern int 1043 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1044 struct journal_head *jh_in, 1045 struct journal_head **jh_out, 1046 unsigned long long blocknr); 1047 1048 /* Transaction locking */ 1049 extern void __wait_on_journal (journal_t *); 1050 1051 /* Transaction cache support */ 1052 extern void jbd2_journal_destroy_transaction_cache(void); 1053 extern int jbd2_journal_init_transaction_cache(void); 1054 extern void jbd2_journal_free_transaction(transaction_t *); 1055 1056 /* 1057 * Journal locking. 1058 * 1059 * We need to lock the journal during transaction state changes so that nobody 1060 * ever tries to take a handle on the running transaction while we are in the 1061 * middle of moving it to the commit phase. j_state_lock does this. 1062 * 1063 * Note that the locking is completely interrupt unsafe. We never touch 1064 * journal structures from interrupts. 1065 */ 1066 1067 static inline handle_t *journal_current_handle(void) 1068 { 1069 return current->journal_info; 1070 } 1071 1072 /* The journaling code user interface: 1073 * 1074 * Create and destroy handles 1075 * Register buffer modifications against the current transaction. 1076 */ 1077 1078 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1079 extern handle_t *jbd2__journal_start(journal_t *, int nblocks, gfp_t gfp_mask, 1080 unsigned int type, unsigned int line_no); 1081 extern int jbd2_journal_restart(handle_t *, int nblocks); 1082 extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask); 1083 extern int jbd2_journal_extend (handle_t *, int nblocks); 1084 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1085 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1086 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1087 void jbd2_journal_set_triggers(struct buffer_head *, 1088 struct jbd2_buffer_trigger_type *type); 1089 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1090 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1091 extern void journal_sync_buffer (struct buffer_head *); 1092 extern int jbd2_journal_invalidatepage(journal_t *, 1093 struct page *, unsigned long); 1094 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1095 extern int jbd2_journal_stop(handle_t *); 1096 extern int jbd2_journal_flush (journal_t *); 1097 extern void jbd2_journal_lock_updates (journal_t *); 1098 extern void jbd2_journal_unlock_updates (journal_t *); 1099 1100 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1101 struct block_device *fs_dev, 1102 unsigned long long start, int len, int bsize); 1103 extern journal_t * jbd2_journal_init_inode (struct inode *); 1104 extern int jbd2_journal_update_format (journal_t *); 1105 extern int jbd2_journal_check_used_features 1106 (journal_t *, unsigned long, unsigned long, unsigned long); 1107 extern int jbd2_journal_check_available_features 1108 (journal_t *, unsigned long, unsigned long, unsigned long); 1109 extern int jbd2_journal_set_features 1110 (journal_t *, unsigned long, unsigned long, unsigned long); 1111 extern void jbd2_journal_clear_features 1112 (journal_t *, unsigned long, unsigned long, unsigned long); 1113 extern int jbd2_journal_load (journal_t *journal); 1114 extern int jbd2_journal_destroy (journal_t *); 1115 extern int jbd2_journal_recover (journal_t *journal); 1116 extern int jbd2_journal_wipe (journal_t *, int); 1117 extern int jbd2_journal_skip_recovery (journal_t *); 1118 extern void jbd2_journal_update_sb_errno(journal_t *); 1119 extern void jbd2_journal_update_sb_log_tail (journal_t *, tid_t, 1120 unsigned long, int); 1121 extern void __jbd2_journal_abort_hard (journal_t *); 1122 extern void jbd2_journal_abort (journal_t *, int); 1123 extern int jbd2_journal_errno (journal_t *); 1124 extern void jbd2_journal_ack_err (journal_t *); 1125 extern int jbd2_journal_clear_err (journal_t *); 1126 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1127 extern int jbd2_journal_force_commit(journal_t *); 1128 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1129 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1130 struct jbd2_inode *inode, loff_t new_size); 1131 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1132 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1133 1134 /* 1135 * journal_head management 1136 */ 1137 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1138 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1139 void jbd2_journal_put_journal_head(struct journal_head *jh); 1140 1141 /* 1142 * handle management 1143 */ 1144 extern struct kmem_cache *jbd2_handle_cache; 1145 1146 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1147 { 1148 return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags); 1149 } 1150 1151 static inline void jbd2_free_handle(handle_t *handle) 1152 { 1153 kmem_cache_free(jbd2_handle_cache, handle); 1154 } 1155 1156 /* 1157 * jbd2_inode management (optional, for those file systems that want to use 1158 * dynamically allocated jbd2_inode structures) 1159 */ 1160 extern struct kmem_cache *jbd2_inode_cache; 1161 1162 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1163 { 1164 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1165 } 1166 1167 static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1168 { 1169 kmem_cache_free(jbd2_inode_cache, jinode); 1170 } 1171 1172 /* Primary revoke support */ 1173 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1174 extern int jbd2_journal_init_revoke(journal_t *, int); 1175 extern void jbd2_journal_destroy_revoke_caches(void); 1176 extern int jbd2_journal_init_revoke_caches(void); 1177 1178 extern void jbd2_journal_destroy_revoke(journal_t *); 1179 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1180 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1181 extern void jbd2_journal_write_revoke_records(journal_t *, 1182 transaction_t *, int); 1183 1184 /* Recovery revoke support */ 1185 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1186 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1187 extern void jbd2_journal_clear_revoke(journal_t *); 1188 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1189 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1190 1191 /* 1192 * The log thread user interface: 1193 * 1194 * Request space in the current transaction, and force transaction commit 1195 * transitions on demand. 1196 */ 1197 1198 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 1199 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1200 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1201 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1202 int jbd2_journal_force_commit_nested(journal_t *journal); 1203 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1204 int jbd2_complete_transaction(journal_t *journal, tid_t tid); 1205 int jbd2_log_do_checkpoint(journal_t *journal); 1206 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 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 += atomic_read(&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 /* JBD uses a CRC32 checksum */ 1298 #define JBD_MAX_CHECKSUM_SIZE 4 1299 1300 static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 1301 const void *address, unsigned int length) 1302 { 1303 struct { 1304 struct shash_desc shash; 1305 char ctx[JBD_MAX_CHECKSUM_SIZE]; 1306 } desc; 1307 int err; 1308 1309 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) > 1310 JBD_MAX_CHECKSUM_SIZE); 1311 1312 desc.shash.tfm = journal->j_chksum_driver; 1313 desc.shash.flags = 0; 1314 *(u32 *)desc.ctx = crc; 1315 1316 err = crypto_shash_update(&desc.shash, address, length); 1317 BUG_ON(err); 1318 1319 return *(u32 *)desc.ctx; 1320 } 1321 1322 #ifdef __KERNEL__ 1323 1324 #define buffer_trace_init(bh) do {} while (0) 1325 #define print_buffer_fields(bh) do {} while (0) 1326 #define print_buffer_trace(bh) do {} while (0) 1327 #define BUFFER_TRACE(bh, info) do {} while (0) 1328 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1329 #define JBUFFER_TRACE(jh, info) do {} while (0) 1330 1331 #endif /* __KERNEL__ */ 1332 1333 #endif /* _LINUX_JBD2_H */ 1334