1 /* 2 * linux/include/linux/jbd2.h 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16 #ifndef _LINUX_JBD2_H 17 #define _LINUX_JBD2_H 18 19 /* Allow this file to be included directly into e2fsprogs */ 20 #ifndef __KERNEL__ 21 #include "jfs_compat.h" 22 #define JBD2_DEBUG 23 #define jfs_debug jbd_debug 24 #else 25 26 #include <linux/types.h> 27 #include <linux/buffer_head.h> 28 #include <linux/journal-head.h> 29 #include <linux/stddef.h> 30 #include <linux/bit_spinlock.h> 31 #include <linux/mutex.h> 32 #include <linux/timer.h> 33 #include <linux/slab.h> 34 #include <crypto/hash.h> 35 #endif 36 37 #define journal_oom_retry 1 38 39 /* 40 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 41 * certain classes of error which can occur due to failed IOs. Under 42 * normal use we want ext4 to continue after such errors, because 43 * hardware _can_ fail, but for debugging purposes when running tests on 44 * known-good hardware we may want to trap these errors. 45 */ 46 #undef JBD2_PARANOID_IOFAIL 47 48 /* 49 * The default maximum commit age, in seconds. 50 */ 51 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5 52 53 #ifdef CONFIG_JBD2_DEBUG 54 /* 55 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 56 * consistency checks. By default we don't do this unless 57 * CONFIG_JBD2_DEBUG is on. 58 */ 59 #define JBD2_EXPENSIVE_CHECKING 60 extern u8 jbd2_journal_enable_debug; 61 62 #define jbd_debug(n, f, a...) \ 63 do { \ 64 if ((n) <= jbd2_journal_enable_debug) { \ 65 printk (KERN_DEBUG "(%s, %d): %s: ", \ 66 __FILE__, __LINE__, __func__); \ 67 printk (f, ## a); \ 68 } \ 69 } while (0) 70 #else 71 #define jbd_debug(f, a...) /**/ 72 #endif 73 74 extern void *jbd2_alloc(size_t size, gfp_t flags); 75 extern void jbd2_free(void *ptr, size_t size); 76 77 #define JBD2_MIN_JOURNAL_BLOCKS 1024 78 79 #ifdef __KERNEL__ 80 81 /** 82 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 83 * 84 * All filesystem modifications made by the process go 85 * through this handle. Recursive operations (such as quota operations) 86 * are gathered into a single update. 87 * 88 * The buffer credits field is used to account for journaled buffers 89 * being modified by the running process. To ensure that there is 90 * enough log space for all outstanding operations, we need to limit the 91 * number of outstanding buffers possible at any time. When the 92 * operation completes, any buffer credits not used are credited back to 93 * the transaction, so that at all times we know how many buffers the 94 * outstanding updates on a transaction might possibly touch. 95 * 96 * This is an opaque datatype. 97 **/ 98 typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */ 99 100 101 /** 102 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 103 * 104 * journal_t is linked to from the fs superblock structure. 105 * 106 * We use the journal_t to keep track of all outstanding transaction 107 * activity on the filesystem, and to manage the state of the log 108 * writing process. 109 * 110 * This is an opaque datatype. 111 **/ 112 typedef struct journal_s journal_t; /* Journal control structure */ 113 #endif 114 115 /* 116 * Internal structures used by the logging mechanism: 117 */ 118 119 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 120 121 /* 122 * On-disk structures 123 */ 124 125 /* 126 * Descriptor block types: 127 */ 128 129 #define JBD2_DESCRIPTOR_BLOCK 1 130 #define JBD2_COMMIT_BLOCK 2 131 #define JBD2_SUPERBLOCK_V1 3 132 #define JBD2_SUPERBLOCK_V2 4 133 #define JBD2_REVOKE_BLOCK 5 134 135 /* 136 * Standard header for all descriptor blocks: 137 */ 138 typedef struct journal_header_s 139 { 140 __be32 h_magic; 141 __be32 h_blocktype; 142 __be32 h_sequence; 143 } journal_header_t; 144 145 /* 146 * Checksum types. 147 */ 148 #define JBD2_CRC32_CHKSUM 1 149 #define JBD2_MD5_CHKSUM 2 150 #define JBD2_SHA1_CHKSUM 3 151 #define JBD2_CRC32C_CHKSUM 4 152 153 #define JBD2_CRC32_CHKSUM_SIZE 4 154 155 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 156 /* 157 * Commit block header for storing transactional checksums: 158 * 159 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* 160 * fields are used to store a checksum of the descriptor and data blocks. 161 * 162 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum 163 * field is used to store crc32c(uuid+commit_block). Each journal metadata 164 * block gets its own checksum, and data block checksums are stored in 165 * journal_block_tag (in the descriptor). The other h_chksum* fields are 166 * not used. 167 * 168 * Checksum v1 and v2 are mutually exclusive features. 169 */ 170 struct commit_header { 171 __be32 h_magic; 172 __be32 h_blocktype; 173 __be32 h_sequence; 174 unsigned char h_chksum_type; 175 unsigned char h_chksum_size; 176 unsigned char h_padding[2]; 177 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 178 __be64 h_commit_sec; 179 __be32 h_commit_nsec; 180 }; 181 182 /* 183 * The block tag: used to describe a single buffer in the journal. 184 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 185 * raw struct shouldn't be used for pointer math or sizeof() - use 186 * journal_tag_bytes(journal) instead to compute this. 187 */ 188 typedef struct journal_block_tag_s 189 { 190 __be32 t_blocknr; /* The on-disk block number */ 191 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ 192 __be16 t_flags; /* See below */ 193 __be32 t_blocknr_high; /* most-significant high 32bits. */ 194 } journal_block_tag_t; 195 196 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 197 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 198 199 /* Tail of descriptor block, for checksumming */ 200 struct jbd2_journal_block_tail { 201 __be32 t_checksum; /* crc32c(uuid+descr_block) */ 202 }; 203 204 /* 205 * The revoke descriptor: used on disk to describe a series of blocks to 206 * be revoked from the log 207 */ 208 typedef struct jbd2_journal_revoke_header_s 209 { 210 journal_header_t r_header; 211 __be32 r_count; /* Count of bytes used in the block */ 212 } jbd2_journal_revoke_header_t; 213 214 /* Tail of revoke block, for checksumming */ 215 struct jbd2_journal_revoke_tail { 216 __be32 r_checksum; /* crc32c(uuid+revoke_block) */ 217 }; 218 219 /* Definitions for the journal tag flags word: */ 220 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 221 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 222 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 223 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 224 225 226 /* 227 * The journal superblock. All fields are in big-endian byte order. 228 */ 229 typedef struct journal_superblock_s 230 { 231 /* 0x0000 */ 232 journal_header_t s_header; 233 234 /* 0x000C */ 235 /* Static information describing the journal */ 236 __be32 s_blocksize; /* journal device blocksize */ 237 __be32 s_maxlen; /* total blocks in journal file */ 238 __be32 s_first; /* first block of log information */ 239 240 /* 0x0018 */ 241 /* Dynamic information describing the current state of the log */ 242 __be32 s_sequence; /* first commit ID expected in log */ 243 __be32 s_start; /* blocknr of start of log */ 244 245 /* 0x0020 */ 246 /* Error value, as set by jbd2_journal_abort(). */ 247 __be32 s_errno; 248 249 /* 0x0024 */ 250 /* Remaining fields are only valid in a version-2 superblock */ 251 __be32 s_feature_compat; /* compatible feature set */ 252 __be32 s_feature_incompat; /* incompatible feature set */ 253 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 254 /* 0x0030 */ 255 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 256 257 /* 0x0040 */ 258 __be32 s_nr_users; /* Nr of filesystems sharing log */ 259 260 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 261 262 /* 0x0048 */ 263 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 264 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 265 266 /* 0x0050 */ 267 __u8 s_checksum_type; /* checksum type */ 268 __u8 s_padding2[3]; 269 __u32 s_padding[42]; 270 __be32 s_checksum; /* crc32c(superblock) */ 271 272 /* 0x0100 */ 273 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 274 /* 0x0400 */ 275 } journal_superblock_t; 276 277 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 278 ((j)->j_format_version >= 2 && \ 279 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 280 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 281 ((j)->j_format_version >= 2 && \ 282 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 283 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 284 ((j)->j_format_version >= 2 && \ 285 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 286 287 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 288 289 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 290 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 291 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 292 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 293 294 /* Features known to this kernel version: */ 295 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 296 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 297 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 298 JBD2_FEATURE_INCOMPAT_64BIT | \ 299 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \ 300 JBD2_FEATURE_INCOMPAT_CSUM_V2) 301 302 #ifdef __KERNEL__ 303 304 #include <linux/fs.h> 305 #include <linux/sched.h> 306 #include <linux/jbd_common.h> 307 308 #define J_ASSERT(assert) BUG_ON(!(assert)) 309 310 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 311 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 312 313 #if defined(JBD2_PARANOID_IOFAIL) 314 #define J_EXPECT(expr, why...) J_ASSERT(expr) 315 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 316 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 317 #else 318 #define __journal_expect(expr, why...) \ 319 ({ \ 320 int val = (expr); \ 321 if (!val) { \ 322 printk(KERN_ERR \ 323 "JBD2 unexpected failure: %s: %s;\n", \ 324 __func__, #expr); \ 325 printk(KERN_ERR why "\n"); \ 326 } \ 327 val; \ 328 }) 329 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 330 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 331 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 332 #endif 333 334 /* Flags in jbd_inode->i_flags */ 335 #define __JI_COMMIT_RUNNING 0 336 /* Commit of the inode data in progress. We use this flag to protect us from 337 * concurrent deletion of inode. We cannot use reference to inode for this 338 * since we cannot afford doing last iput() on behalf of kjournald 339 */ 340 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 341 342 /** 343 * struct jbd_inode is the structure linking inodes in ordered mode 344 * present in a transaction so that we can sync them during commit. 345 */ 346 struct jbd2_inode { 347 /* Which transaction does this inode belong to? Either the running 348 * transaction or the committing one. [j_list_lock] */ 349 transaction_t *i_transaction; 350 351 /* Pointer to the running transaction modifying inode's data in case 352 * there is already a committing transaction touching it. [j_list_lock] */ 353 transaction_t *i_next_transaction; 354 355 /* List of inodes in the i_transaction [j_list_lock] */ 356 struct list_head i_list; 357 358 /* VFS inode this inode belongs to [constant during the lifetime 359 * of the structure] */ 360 struct inode *i_vfs_inode; 361 362 /* Flags of inode [j_list_lock] */ 363 unsigned long i_flags; 364 }; 365 366 struct jbd2_revoke_table_s; 367 368 /** 369 * struct handle_s - The handle_s type is the concrete type associated with 370 * handle_t. 371 * @h_transaction: Which compound transaction is this update a part of? 372 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 373 * @h_ref: Reference count on this handle 374 * @h_err: Field for caller's use to track errors through large fs operations 375 * @h_sync: flag for sync-on-close 376 * @h_jdata: flag to force data journaling 377 * @h_aborted: flag indicating fatal error on handle 378 **/ 379 380 /* Docbook can't yet cope with the bit fields, but will leave the documentation 381 * in so it can be fixed later. 382 */ 383 384 struct jbd2_journal_handle 385 { 386 /* Which compound transaction is this update a part of? */ 387 transaction_t *h_transaction; 388 389 /* Number of remaining buffers we are allowed to dirty: */ 390 int h_buffer_credits; 391 392 /* Reference count on this handle */ 393 int h_ref; 394 395 /* Field for caller's use to track errors through large fs */ 396 /* operations */ 397 int h_err; 398 399 /* Flags [no locking] */ 400 unsigned int h_sync:1; /* sync-on-close */ 401 unsigned int h_jdata:1; /* force data journaling */ 402 unsigned int h_aborted:1; /* fatal error on handle */ 403 unsigned int h_cowing:1; /* COWing block to snapshot */ 404 405 /* Number of buffers requested by user: 406 * (before adding the COW credits factor) */ 407 unsigned int h_base_credits:14; 408 409 /* Number of buffers the user is allowed to dirty: 410 * (counts only buffers dirtied when !h_cowing) */ 411 unsigned int h_user_credits:14; 412 413 414 #ifdef CONFIG_DEBUG_LOCK_ALLOC 415 struct lockdep_map h_lockdep_map; 416 #endif 417 418 #ifdef CONFIG_JBD2_DEBUG 419 /* COW debugging counters: */ 420 unsigned int h_cow_moved; /* blocks moved to snapshot */ 421 unsigned int h_cow_copied; /* blocks copied to snapshot */ 422 unsigned int h_cow_ok_jh; /* blocks already COWed during current 423 transaction */ 424 unsigned int h_cow_ok_bitmap; /* blocks not set in COW bitmap */ 425 unsigned int h_cow_ok_mapped;/* blocks already mapped in snapshot */ 426 unsigned int h_cow_bitmaps; /* COW bitmaps created */ 427 unsigned int h_cow_excluded; /* blocks set in exclude bitmap */ 428 #endif 429 }; 430 431 432 /* 433 * Some stats for checkpoint phase 434 */ 435 struct transaction_chp_stats_s { 436 unsigned long cs_chp_time; 437 __u32 cs_forced_to_close; 438 __u32 cs_written; 439 __u32 cs_dropped; 440 }; 441 442 /* The transaction_t type is the guts of the journaling mechanism. It 443 * tracks a compound transaction through its various states: 444 * 445 * RUNNING: accepting new updates 446 * LOCKED: Updates still running but we don't accept new ones 447 * RUNDOWN: Updates are tidying up but have finished requesting 448 * new buffers to modify (state not used for now) 449 * FLUSH: All updates complete, but we are still writing to disk 450 * COMMIT: All data on disk, writing commit record 451 * FINISHED: We still have to keep the transaction for checkpointing. 452 * 453 * The transaction keeps track of all of the buffers modified by a 454 * running transaction, and all of the buffers committed but not yet 455 * flushed to home for finished transactions. 456 */ 457 458 /* 459 * Lock ranking: 460 * 461 * j_list_lock 462 * ->jbd_lock_bh_journal_head() (This is "innermost") 463 * 464 * j_state_lock 465 * ->jbd_lock_bh_state() 466 * 467 * jbd_lock_bh_state() 468 * ->j_list_lock 469 * 470 * j_state_lock 471 * ->t_handle_lock 472 * 473 * j_state_lock 474 * ->j_list_lock (journal_unmap_buffer) 475 * 476 */ 477 478 struct transaction_s 479 { 480 /* Pointer to the journal for this transaction. [no locking] */ 481 journal_t *t_journal; 482 483 /* Sequence number for this transaction [no locking] */ 484 tid_t t_tid; 485 486 /* 487 * Transaction's current state 488 * [no locking - only kjournald2 alters this] 489 * [j_list_lock] guards transition of a transaction into T_FINISHED 490 * state and subsequent call of __jbd2_journal_drop_transaction() 491 * FIXME: needs barriers 492 * KLUDGE: [use j_state_lock] 493 */ 494 enum { 495 T_RUNNING, 496 T_LOCKED, 497 T_FLUSH, 498 T_COMMIT, 499 T_COMMIT_DFLUSH, 500 T_COMMIT_JFLUSH, 501 T_FINISHED 502 } t_state; 503 504 /* 505 * Where in the log does this transaction's commit start? [no locking] 506 */ 507 unsigned long t_log_start; 508 509 /* Number of buffers on the t_buffers list [j_list_lock] */ 510 int t_nr_buffers; 511 512 /* 513 * Doubly-linked circular list of all buffers reserved but not yet 514 * modified by this transaction [j_list_lock] 515 */ 516 struct journal_head *t_reserved_list; 517 518 /* 519 * Doubly-linked circular list of all metadata buffers owned by this 520 * transaction [j_list_lock] 521 */ 522 struct journal_head *t_buffers; 523 524 /* 525 * Doubly-linked circular list of all forget buffers (superseded 526 * buffers which we can un-checkpoint once this transaction commits) 527 * [j_list_lock] 528 */ 529 struct journal_head *t_forget; 530 531 /* 532 * Doubly-linked circular list of all buffers still to be flushed before 533 * this transaction can be checkpointed. [j_list_lock] 534 */ 535 struct journal_head *t_checkpoint_list; 536 537 /* 538 * Doubly-linked circular list of all buffers submitted for IO while 539 * checkpointing. [j_list_lock] 540 */ 541 struct journal_head *t_checkpoint_io_list; 542 543 /* 544 * Doubly-linked circular list of temporary buffers currently undergoing 545 * IO in the log [j_list_lock] 546 */ 547 struct journal_head *t_iobuf_list; 548 549 /* 550 * Doubly-linked circular list of metadata buffers being shadowed by log 551 * IO. The IO buffers on the iobuf list and the shadow buffers on this 552 * list match each other one for one at all times. [j_list_lock] 553 */ 554 struct journal_head *t_shadow_list; 555 556 /* 557 * Doubly-linked circular list of control buffers being written to the 558 * log. [j_list_lock] 559 */ 560 struct journal_head *t_log_list; 561 562 /* 563 * List of inodes whose data we've modified in data=ordered mode. 564 * [j_list_lock] 565 */ 566 struct list_head t_inode_list; 567 568 /* 569 * Protects info related to handles 570 */ 571 spinlock_t t_handle_lock; 572 573 /* 574 * Longest time some handle had to wait for running transaction 575 */ 576 unsigned long t_max_wait; 577 578 /* 579 * When transaction started 580 */ 581 unsigned long t_start; 582 583 /* 584 * Checkpointing stats [j_checkpoint_sem] 585 */ 586 struct transaction_chp_stats_s t_chp_stats; 587 588 /* 589 * Number of outstanding updates running on this transaction 590 * [t_handle_lock] 591 */ 592 atomic_t t_updates; 593 594 /* 595 * Number of buffers reserved for use by all handles in this transaction 596 * handle but not yet modified. [t_handle_lock] 597 */ 598 atomic_t t_outstanding_credits; 599 600 /* 601 * Forward and backward links for the circular list of all transactions 602 * awaiting checkpoint. [j_list_lock] 603 */ 604 transaction_t *t_cpnext, *t_cpprev; 605 606 /* 607 * When will the transaction expire (become due for commit), in jiffies? 608 * [no locking] 609 */ 610 unsigned long t_expires; 611 612 /* 613 * When this transaction started, in nanoseconds [no locking] 614 */ 615 ktime_t t_start_time; 616 617 /* 618 * How many handles used this transaction? [t_handle_lock] 619 */ 620 atomic_t t_handle_count; 621 622 /* 623 * This transaction is being forced and some process is 624 * waiting for it to finish. 625 */ 626 unsigned int t_synchronous_commit:1; 627 628 /* Disk flush needs to be sent to fs partition [no locking] */ 629 int t_need_data_flush; 630 631 /* 632 * For use by the filesystem to store fs-specific data 633 * structures associated with the transaction 634 */ 635 struct list_head t_private_list; 636 }; 637 638 struct transaction_run_stats_s { 639 unsigned long rs_wait; 640 unsigned long rs_running; 641 unsigned long rs_locked; 642 unsigned long rs_flushing; 643 unsigned long rs_logging; 644 645 __u32 rs_handle_count; 646 __u32 rs_blocks; 647 __u32 rs_blocks_logged; 648 }; 649 650 struct transaction_stats_s { 651 unsigned long ts_tid; 652 struct transaction_run_stats_s run; 653 }; 654 655 static inline unsigned long 656 jbd2_time_diff(unsigned long start, unsigned long end) 657 { 658 if (end >= start) 659 return end - start; 660 661 return end + (MAX_JIFFY_OFFSET - start); 662 } 663 664 #define JBD2_NR_BATCH 64 665 666 /** 667 * struct journal_s - The journal_s type is the concrete type associated with 668 * journal_t. 669 * @j_flags: General journaling state flags 670 * @j_errno: Is there an outstanding uncleared error on the journal (from a 671 * prior abort)? 672 * @j_sb_buffer: First part of superblock buffer 673 * @j_superblock: Second part of superblock buffer 674 * @j_format_version: Version of the superblock format 675 * @j_state_lock: Protect the various scalars in the journal 676 * @j_barrier_count: Number of processes waiting to create a barrier lock 677 * @j_barrier: The barrier lock itself 678 * @j_running_transaction: The current running transaction.. 679 * @j_committing_transaction: the transaction we are pushing to disk 680 * @j_checkpoint_transactions: a linked circular list of all transactions 681 * waiting for checkpointing 682 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 683 * to start committing, or for a barrier lock to be released 684 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 685 * @j_wait_done_commit: Wait queue for waiting for commit to complete 686 * @j_wait_checkpoint: Wait queue to trigger checkpointing 687 * @j_wait_commit: Wait queue to trigger commit 688 * @j_wait_updates: Wait queue to wait for updates to complete 689 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 690 * @j_head: Journal head - identifies the first unused block in the journal 691 * @j_tail: Journal tail - identifies the oldest still-used block in the 692 * journal. 693 * @j_free: Journal free - how many free blocks are there in the journal? 694 * @j_first: The block number of the first usable block 695 * @j_last: The block number one beyond the last usable block 696 * @j_dev: Device where we store the journal 697 * @j_blocksize: blocksize for the location where we store the journal. 698 * @j_blk_offset: starting block offset for into the device where we store the 699 * journal 700 * @j_fs_dev: Device which holds the client fs. For internal journal this will 701 * be equal to j_dev 702 * @j_maxlen: Total maximum capacity of the journal region on disk. 703 * @j_list_lock: Protects the buffer lists and internal buffer state. 704 * @j_inode: Optional inode where we store the journal. If present, all journal 705 * block numbers are mapped into this inode via bmap(). 706 * @j_tail_sequence: Sequence number of the oldest transaction in the log 707 * @j_transaction_sequence: Sequence number of the next transaction to grant 708 * @j_commit_sequence: Sequence number of the most recently committed 709 * transaction 710 * @j_commit_request: Sequence number of the most recent transaction wanting 711 * commit 712 * @j_uuid: Uuid of client object. 713 * @j_task: Pointer to the current commit thread for this journal 714 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 715 * single compound commit transaction 716 * @j_commit_interval: What is the maximum transaction lifetime before we begin 717 * a commit? 718 * @j_commit_timer: The timer used to wakeup the commit thread 719 * @j_revoke_lock: Protect the revoke table 720 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 721 * current transaction. 722 * @j_revoke_table: alternate revoke tables for j_revoke 723 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 724 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 725 * number that will fit in j_blocksize 726 * @j_last_sync_writer: most recent pid which did a synchronous write 727 * @j_history: Buffer storing the transactions statistics history 728 * @j_history_max: Maximum number of transactions in the statistics history 729 * @j_history_cur: Current number of transactions in the statistics history 730 * @j_history_lock: Protect the transactions statistics history 731 * @j_proc_entry: procfs entry for the jbd statistics directory 732 * @j_stats: Overall statistics 733 * @j_private: An opaque pointer to fs-private information. 734 */ 735 736 struct journal_s 737 { 738 /* General journaling state flags [j_state_lock] */ 739 unsigned long j_flags; 740 741 /* 742 * Is there an outstanding uncleared error on the journal (from a prior 743 * abort)? [j_state_lock] 744 */ 745 int j_errno; 746 747 /* The superblock buffer */ 748 struct buffer_head *j_sb_buffer; 749 journal_superblock_t *j_superblock; 750 751 /* Version of the superblock format */ 752 int j_format_version; 753 754 /* 755 * Protect the various scalars in the journal 756 */ 757 rwlock_t j_state_lock; 758 759 /* 760 * Number of processes waiting to create a barrier lock [j_state_lock] 761 */ 762 int j_barrier_count; 763 764 /* The barrier lock itself */ 765 struct mutex j_barrier; 766 767 /* 768 * Transactions: The current running transaction... 769 * [j_state_lock] [caller holding open handle] 770 */ 771 transaction_t *j_running_transaction; 772 773 /* 774 * the transaction we are pushing to disk 775 * [j_state_lock] [caller holding open handle] 776 */ 777 transaction_t *j_committing_transaction; 778 779 /* 780 * ... and a linked circular list of all transactions waiting for 781 * checkpointing. [j_list_lock] 782 */ 783 transaction_t *j_checkpoint_transactions; 784 785 /* 786 * Wait queue for waiting for a locked transaction to start committing, 787 * or for a barrier lock to be released 788 */ 789 wait_queue_head_t j_wait_transaction_locked; 790 791 /* Wait queue for waiting for checkpointing to complete */ 792 wait_queue_head_t j_wait_logspace; 793 794 /* Wait queue for waiting for commit to complete */ 795 wait_queue_head_t j_wait_done_commit; 796 797 /* Wait queue to trigger checkpointing */ 798 wait_queue_head_t j_wait_checkpoint; 799 800 /* Wait queue to trigger commit */ 801 wait_queue_head_t j_wait_commit; 802 803 /* Wait queue to wait for updates to complete */ 804 wait_queue_head_t j_wait_updates; 805 806 /* Semaphore for locking against concurrent checkpoints */ 807 struct mutex j_checkpoint_mutex; 808 809 /* 810 * List of buffer heads used by the checkpoint routine. This 811 * was moved from jbd2_log_do_checkpoint() to reduce stack 812 * usage. Access to this array is controlled by the 813 * j_checkpoint_mutex. [j_checkpoint_mutex] 814 */ 815 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 816 817 /* 818 * Journal head: identifies the first unused block in the journal. 819 * [j_state_lock] 820 */ 821 unsigned long j_head; 822 823 /* 824 * Journal tail: identifies the oldest still-used block in the journal. 825 * [j_state_lock] 826 */ 827 unsigned long j_tail; 828 829 /* 830 * Journal free: how many free blocks are there in the journal? 831 * [j_state_lock] 832 */ 833 unsigned long j_free; 834 835 /* 836 * Journal start and end: the block numbers of the first usable block 837 * and one beyond the last usable block in the journal. [j_state_lock] 838 */ 839 unsigned long j_first; 840 unsigned long j_last; 841 842 /* 843 * Device, blocksize and starting block offset for the location where we 844 * store the journal. 845 */ 846 struct block_device *j_dev; 847 int j_blocksize; 848 unsigned long long j_blk_offset; 849 char j_devname[BDEVNAME_SIZE+24]; 850 851 /* 852 * Device which holds the client fs. For internal journal this will be 853 * equal to j_dev. 854 */ 855 struct block_device *j_fs_dev; 856 857 /* Total maximum capacity of the journal region on disk. */ 858 unsigned int j_maxlen; 859 860 /* 861 * Protects the buffer lists and internal buffer state. 862 */ 863 spinlock_t j_list_lock; 864 865 /* Optional inode where we store the journal. If present, all */ 866 /* journal block numbers are mapped into this inode via */ 867 /* bmap(). */ 868 struct inode *j_inode; 869 870 /* 871 * Sequence number of the oldest transaction in the log [j_state_lock] 872 */ 873 tid_t j_tail_sequence; 874 875 /* 876 * Sequence number of the next transaction to grant [j_state_lock] 877 */ 878 tid_t j_transaction_sequence; 879 880 /* 881 * Sequence number of the most recently committed transaction 882 * [j_state_lock]. 883 */ 884 tid_t j_commit_sequence; 885 886 /* 887 * Sequence number of the most recent transaction wanting commit 888 * [j_state_lock] 889 */ 890 tid_t j_commit_request; 891 892 /* 893 * Journal uuid: identifies the object (filesystem, LVM volume etc) 894 * backed by this journal. This will eventually be replaced by an array 895 * of uuids, allowing us to index multiple devices within a single 896 * journal and to perform atomic updates across them. 897 */ 898 __u8 j_uuid[16]; 899 900 /* Pointer to the current commit thread for this journal */ 901 struct task_struct *j_task; 902 903 /* 904 * Maximum number of metadata buffers to allow in a single compound 905 * commit transaction 906 */ 907 int j_max_transaction_buffers; 908 909 /* 910 * What is the maximum transaction lifetime before we begin a commit? 911 */ 912 unsigned long j_commit_interval; 913 914 /* The timer used to wakeup the commit thread: */ 915 struct timer_list j_commit_timer; 916 917 /* 918 * The revoke table: maintains the list of revoked blocks in the 919 * current transaction. [j_revoke_lock] 920 */ 921 spinlock_t j_revoke_lock; 922 struct jbd2_revoke_table_s *j_revoke; 923 struct jbd2_revoke_table_s *j_revoke_table[2]; 924 925 /* 926 * array of bhs for jbd2_journal_commit_transaction 927 */ 928 struct buffer_head **j_wbuf; 929 int j_wbufsize; 930 931 /* 932 * this is the pid of hte last person to run a synchronous operation 933 * through the journal 934 */ 935 pid_t j_last_sync_writer; 936 937 /* 938 * the average amount of time in nanoseconds it takes to commit a 939 * transaction to disk. [j_state_lock] 940 */ 941 u64 j_average_commit_time; 942 943 /* 944 * minimum and maximum times that we should wait for 945 * additional filesystem operations to get batched into a 946 * synchronous handle in microseconds 947 */ 948 u32 j_min_batch_time; 949 u32 j_max_batch_time; 950 951 /* This function is called when a transaction is closed */ 952 void (*j_commit_callback)(journal_t *, 953 transaction_t *); 954 955 /* 956 * Journal statistics 957 */ 958 spinlock_t j_history_lock; 959 struct proc_dir_entry *j_proc_entry; 960 struct transaction_stats_s j_stats; 961 962 /* Failed journal commit ID */ 963 unsigned int j_failed_commit; 964 965 /* 966 * An opaque pointer to fs-private information. ext3 puts its 967 * superblock pointer here 968 */ 969 void *j_private; 970 971 /* Reference to checksum algorithm driver via cryptoapi */ 972 struct crypto_shash *j_chksum_driver; 973 974 /* Precomputed journal UUID checksum for seeding other checksums */ 975 __u32 j_csum_seed; 976 }; 977 978 /* 979 * Journal flag definitions 980 */ 981 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 982 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 983 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 984 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 985 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 986 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 987 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 988 * data write error in ordered 989 * mode */ 990 991 /* 992 * Function declarations for the journaling transaction and buffer 993 * management 994 */ 995 996 /* Filing buffers */ 997 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 998 extern void __jbd2_journal_refile_buffer(struct journal_head *); 999 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 1000 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1001 extern void __journal_free_buffer(struct journal_head *bh); 1002 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1003 extern void __journal_clean_data_list(transaction_t *transaction); 1004 1005 /* Log buffer allocation */ 1006 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 1007 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 1008 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 1009 unsigned long *block); 1010 void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1011 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1012 1013 /* Commit management */ 1014 extern void jbd2_journal_commit_transaction(journal_t *); 1015 1016 /* Checkpoint list management */ 1017 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 1018 int __jbd2_journal_remove_checkpoint(struct journal_head *); 1019 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1020 1021 1022 /* 1023 * Triggers 1024 */ 1025 1026 struct jbd2_buffer_trigger_type { 1027 /* 1028 * Fired a the moment data to write to the journal are known to be 1029 * stable - so either at the moment b_frozen_data is created or just 1030 * before a buffer is written to the journal. mapped_data is a mapped 1031 * buffer that is the frozen data for commit. 1032 */ 1033 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 1034 struct buffer_head *bh, void *mapped_data, 1035 size_t size); 1036 1037 /* 1038 * Fired during journal abort for dirty buffers that will not be 1039 * committed. 1040 */ 1041 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1042 struct buffer_head *bh); 1043 }; 1044 1045 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1046 void *mapped_data, 1047 struct jbd2_buffer_trigger_type *triggers); 1048 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1049 struct jbd2_buffer_trigger_type *triggers); 1050 1051 /* Buffer IO */ 1052 extern int 1053 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1054 struct journal_head *jh_in, 1055 struct journal_head **jh_out, 1056 unsigned long long blocknr); 1057 1058 /* Transaction locking */ 1059 extern void __wait_on_journal (journal_t *); 1060 1061 /* Transaction cache support */ 1062 extern void jbd2_journal_destroy_transaction_cache(void); 1063 extern int jbd2_journal_init_transaction_cache(void); 1064 extern void jbd2_journal_free_transaction(transaction_t *); 1065 1066 /* 1067 * Journal locking. 1068 * 1069 * We need to lock the journal during transaction state changes so that nobody 1070 * ever tries to take a handle on the running transaction while we are in the 1071 * middle of moving it to the commit phase. j_state_lock does this. 1072 * 1073 * Note that the locking is completely interrupt unsafe. We never touch 1074 * journal structures from interrupts. 1075 */ 1076 1077 static inline handle_t *journal_current_handle(void) 1078 { 1079 return current->journal_info; 1080 } 1081 1082 /* The journaling code user interface: 1083 * 1084 * Create and destroy handles 1085 * Register buffer modifications against the current transaction. 1086 */ 1087 1088 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1089 extern handle_t *jbd2__journal_start(journal_t *, int nblocks, gfp_t gfp_mask); 1090 extern int jbd2_journal_restart(handle_t *, int nblocks); 1091 extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask); 1092 extern int jbd2_journal_extend (handle_t *, int nblocks); 1093 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1094 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1095 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1096 void jbd2_journal_set_triggers(struct buffer_head *, 1097 struct jbd2_buffer_trigger_type *type); 1098 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1099 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 1100 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1101 extern void journal_sync_buffer (struct buffer_head *); 1102 extern void jbd2_journal_invalidatepage(journal_t *, 1103 struct page *, unsigned long); 1104 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1105 extern int jbd2_journal_stop(handle_t *); 1106 extern int jbd2_journal_flush (journal_t *); 1107 extern void jbd2_journal_lock_updates (journal_t *); 1108 extern void jbd2_journal_unlock_updates (journal_t *); 1109 1110 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1111 struct block_device *fs_dev, 1112 unsigned long long start, int len, int bsize); 1113 extern journal_t * jbd2_journal_init_inode (struct inode *); 1114 extern int jbd2_journal_update_format (journal_t *); 1115 extern int jbd2_journal_check_used_features 1116 (journal_t *, unsigned long, unsigned long, unsigned long); 1117 extern int jbd2_journal_check_available_features 1118 (journal_t *, unsigned long, unsigned long, unsigned long); 1119 extern int jbd2_journal_set_features 1120 (journal_t *, unsigned long, unsigned long, unsigned long); 1121 extern void jbd2_journal_clear_features 1122 (journal_t *, unsigned long, unsigned long, unsigned long); 1123 extern int jbd2_journal_load (journal_t *journal); 1124 extern int jbd2_journal_destroy (journal_t *); 1125 extern int jbd2_journal_recover (journal_t *journal); 1126 extern int jbd2_journal_wipe (journal_t *, int); 1127 extern int jbd2_journal_skip_recovery (journal_t *); 1128 extern void jbd2_journal_update_sb_errno(journal_t *); 1129 extern void jbd2_journal_update_sb_log_tail (journal_t *, tid_t, 1130 unsigned long, int); 1131 extern void __jbd2_journal_abort_hard (journal_t *); 1132 extern void jbd2_journal_abort (journal_t *, int); 1133 extern int jbd2_journal_errno (journal_t *); 1134 extern void jbd2_journal_ack_err (journal_t *); 1135 extern int jbd2_journal_clear_err (journal_t *); 1136 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1137 extern int jbd2_journal_force_commit(journal_t *); 1138 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1139 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1140 struct jbd2_inode *inode, loff_t new_size); 1141 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1142 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1143 1144 /* 1145 * journal_head management 1146 */ 1147 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1148 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1149 void jbd2_journal_put_journal_head(struct journal_head *jh); 1150 1151 /* 1152 * handle management 1153 */ 1154 extern struct kmem_cache *jbd2_handle_cache; 1155 1156 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1157 { 1158 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 1159 } 1160 1161 static inline void jbd2_free_handle(handle_t *handle) 1162 { 1163 kmem_cache_free(jbd2_handle_cache, handle); 1164 } 1165 1166 /* 1167 * jbd2_inode management (optional, for those file systems that want to use 1168 * dynamically allocated jbd2_inode structures) 1169 */ 1170 extern struct kmem_cache *jbd2_inode_cache; 1171 1172 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1173 { 1174 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1175 } 1176 1177 static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1178 { 1179 kmem_cache_free(jbd2_inode_cache, jinode); 1180 } 1181 1182 /* Primary revoke support */ 1183 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1184 extern int jbd2_journal_init_revoke(journal_t *, int); 1185 extern void jbd2_journal_destroy_revoke_caches(void); 1186 extern int jbd2_journal_init_revoke_caches(void); 1187 1188 extern void jbd2_journal_destroy_revoke(journal_t *); 1189 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1190 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1191 extern void jbd2_journal_write_revoke_records(journal_t *, 1192 transaction_t *, int); 1193 1194 /* Recovery revoke support */ 1195 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1196 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1197 extern void jbd2_journal_clear_revoke(journal_t *); 1198 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1199 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1200 1201 /* 1202 * The log thread user interface: 1203 * 1204 * Request space in the current transaction, and force transaction commit 1205 * transitions on demand. 1206 */ 1207 1208 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 1209 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1210 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1211 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1212 int jbd2_journal_force_commit_nested(journal_t *journal); 1213 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1214 int jbd2_log_do_checkpoint(journal_t *journal); 1215 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 1216 1217 void __jbd2_log_wait_for_space(journal_t *journal); 1218 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1219 extern int jbd2_cleanup_journal_tail(journal_t *); 1220 1221 /* Debugging code only: */ 1222 1223 #define jbd_ENOSYS() \ 1224 do { \ 1225 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \ 1226 current->state = TASK_UNINTERRUPTIBLE; \ 1227 schedule(); \ 1228 } while (1) 1229 1230 /* 1231 * is_journal_abort 1232 * 1233 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1234 * bit, when set, indicates that we have had a fatal error somewhere, 1235 * either inside the journaling layer or indicated to us by the client 1236 * (eg. ext3), and that we and should not commit any further 1237 * transactions. 1238 */ 1239 1240 static inline int is_journal_aborted(journal_t *journal) 1241 { 1242 return journal->j_flags & JBD2_ABORT; 1243 } 1244 1245 static inline int is_handle_aborted(handle_t *handle) 1246 { 1247 if (handle->h_aborted) 1248 return 1; 1249 return is_journal_aborted(handle->h_transaction->t_journal); 1250 } 1251 1252 static inline void jbd2_journal_abort_handle(handle_t *handle) 1253 { 1254 handle->h_aborted = 1; 1255 } 1256 1257 #endif /* __KERNEL__ */ 1258 1259 /* Comparison functions for transaction IDs: perform comparisons using 1260 * modulo arithmetic so that they work over sequence number wraps. */ 1261 1262 static inline int tid_gt(tid_t x, tid_t y) 1263 { 1264 int difference = (x - y); 1265 return (difference > 0); 1266 } 1267 1268 static inline int tid_geq(tid_t x, tid_t y) 1269 { 1270 int difference = (x - y); 1271 return (difference >= 0); 1272 } 1273 1274 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1275 extern size_t journal_tag_bytes(journal_t *journal); 1276 1277 /* 1278 * Return the minimum number of blocks which must be free in the journal 1279 * before a new transaction may be started. Must be called under j_state_lock. 1280 */ 1281 static inline int jbd_space_needed(journal_t *journal) 1282 { 1283 int nblocks = journal->j_max_transaction_buffers; 1284 if (journal->j_committing_transaction) 1285 nblocks += atomic_read(&journal->j_committing_transaction-> 1286 t_outstanding_credits); 1287 return nblocks; 1288 } 1289 1290 /* 1291 * Definitions which augment the buffer_head layer 1292 */ 1293 1294 /* journaling buffer types */ 1295 #define BJ_None 0 /* Not journaled */ 1296 #define BJ_Metadata 1 /* Normal journaled metadata */ 1297 #define BJ_Forget 2 /* Buffer superseded by this transaction */ 1298 #define BJ_IO 3 /* Buffer is for temporary IO use */ 1299 #define BJ_Shadow 4 /* Buffer contents being shadowed to the log */ 1300 #define BJ_LogCtl 5 /* Buffer contains log descriptors */ 1301 #define BJ_Reserved 6 /* Buffer is reserved for access by journal */ 1302 #define BJ_Types 7 1303 1304 extern int jbd_blocks_per_page(struct inode *inode); 1305 1306 static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 1307 const void *address, unsigned int length) 1308 { 1309 struct { 1310 struct shash_desc shash; 1311 char ctx[crypto_shash_descsize(journal->j_chksum_driver)]; 1312 } desc; 1313 int err; 1314 1315 desc.shash.tfm = journal->j_chksum_driver; 1316 desc.shash.flags = 0; 1317 *(u32 *)desc.ctx = crc; 1318 1319 err = crypto_shash_update(&desc.shash, address, length); 1320 BUG_ON(err); 1321 1322 return *(u32 *)desc.ctx; 1323 } 1324 1325 #ifdef __KERNEL__ 1326 1327 #define buffer_trace_init(bh) do {} while (0) 1328 #define print_buffer_fields(bh) do {} while (0) 1329 #define print_buffer_trace(bh) do {} while (0) 1330 #define BUFFER_TRACE(bh, info) do {} while (0) 1331 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1332 #define JBUFFER_TRACE(jh, info) do {} while (0) 1333 1334 #endif /* __KERNEL__ */ 1335 1336 #endif /* _LINUX_JBD2_H */ 1337