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 #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 u8 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 3 150 151 #define JBD2_CRC32_CHKSUM_SIZE 4 152 153 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 154 /* 155 * Commit block header for storing transactional checksums: 156 */ 157 struct commit_header { 158 __be32 h_magic; 159 __be32 h_blocktype; 160 __be32 h_sequence; 161 unsigned char h_chksum_type; 162 unsigned char h_chksum_size; 163 unsigned char h_padding[2]; 164 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 165 __be64 h_commit_sec; 166 __be32 h_commit_nsec; 167 }; 168 169 /* 170 * The block tag: used to describe a single buffer in the journal. 171 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 172 * raw struct shouldn't be used for pointer math or sizeof() - use 173 * journal_tag_bytes(journal) instead to compute this. 174 */ 175 typedef struct journal_block_tag_s 176 { 177 __be32 t_blocknr; /* The on-disk block number */ 178 __be32 t_flags; /* See below */ 179 __be32 t_blocknr_high; /* most-significant high 32bits. */ 180 } journal_block_tag_t; 181 182 #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) 183 #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) 184 185 /* 186 * The revoke descriptor: used on disk to describe a series of blocks to 187 * be revoked from the log 188 */ 189 typedef struct jbd2_journal_revoke_header_s 190 { 191 journal_header_t r_header; 192 __be32 r_count; /* Count of bytes used in the block */ 193 } jbd2_journal_revoke_header_t; 194 195 196 /* Definitions for the journal tag flags word: */ 197 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 198 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 199 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 200 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 201 202 203 /* 204 * The journal superblock. All fields are in big-endian byte order. 205 */ 206 typedef struct journal_superblock_s 207 { 208 /* 0x0000 */ 209 journal_header_t s_header; 210 211 /* 0x000C */ 212 /* Static information describing the journal */ 213 __be32 s_blocksize; /* journal device blocksize */ 214 __be32 s_maxlen; /* total blocks in journal file */ 215 __be32 s_first; /* first block of log information */ 216 217 /* 0x0018 */ 218 /* Dynamic information describing the current state of the log */ 219 __be32 s_sequence; /* first commit ID expected in log */ 220 __be32 s_start; /* blocknr of start of log */ 221 222 /* 0x0020 */ 223 /* Error value, as set by jbd2_journal_abort(). */ 224 __be32 s_errno; 225 226 /* 0x0024 */ 227 /* Remaining fields are only valid in a version-2 superblock */ 228 __be32 s_feature_compat; /* compatible feature set */ 229 __be32 s_feature_incompat; /* incompatible feature set */ 230 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 231 /* 0x0030 */ 232 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 233 234 /* 0x0040 */ 235 __be32 s_nr_users; /* Nr of filesystems sharing log */ 236 237 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 238 239 /* 0x0048 */ 240 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 241 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 242 243 /* 0x0050 */ 244 __u32 s_padding[44]; 245 246 /* 0x0100 */ 247 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 248 /* 0x0400 */ 249 } journal_superblock_t; 250 251 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 252 ((j)->j_format_version >= 2 && \ 253 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 254 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 255 ((j)->j_format_version >= 2 && \ 256 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 257 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 258 ((j)->j_format_version >= 2 && \ 259 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 260 261 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 262 263 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 264 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 265 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 266 267 /* Features known to this kernel version: */ 268 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 269 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 270 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 271 JBD2_FEATURE_INCOMPAT_64BIT | \ 272 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) 273 274 #ifdef __KERNEL__ 275 276 #include <linux/fs.h> 277 #include <linux/sched.h> 278 #include <linux/jbd_common.h> 279 280 #define J_ASSERT(assert) BUG_ON(!(assert)) 281 282 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 283 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 284 285 #if defined(JBD2_PARANOID_IOFAIL) 286 #define J_EXPECT(expr, why...) J_ASSERT(expr) 287 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 288 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 289 #else 290 #define __journal_expect(expr, why...) \ 291 ({ \ 292 int val = (expr); \ 293 if (!val) { \ 294 printk(KERN_ERR \ 295 "JBD2 unexpected failure: %s: %s;\n", \ 296 __func__, #expr); \ 297 printk(KERN_ERR why "\n"); \ 298 } \ 299 val; \ 300 }) 301 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 302 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 303 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 304 #endif 305 306 /* Flags in jbd_inode->i_flags */ 307 #define __JI_COMMIT_RUNNING 0 308 /* Commit of the inode data in progress. We use this flag to protect us from 309 * concurrent deletion of inode. We cannot use reference to inode for this 310 * since we cannot afford doing last iput() on behalf of kjournald 311 */ 312 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 313 314 /** 315 * struct jbd_inode is the structure linking inodes in ordered mode 316 * present in a transaction so that we can sync them during commit. 317 */ 318 struct jbd2_inode { 319 /* Which transaction does this inode belong to? Either the running 320 * transaction or the committing one. [j_list_lock] */ 321 transaction_t *i_transaction; 322 323 /* Pointer to the running transaction modifying inode's data in case 324 * there is already a committing transaction touching it. [j_list_lock] */ 325 transaction_t *i_next_transaction; 326 327 /* List of inodes in the i_transaction [j_list_lock] */ 328 struct list_head i_list; 329 330 /* VFS inode this inode belongs to [constant during the lifetime 331 * of the structure] */ 332 struct inode *i_vfs_inode; 333 334 /* Flags of inode [j_list_lock] */ 335 unsigned long i_flags; 336 }; 337 338 struct jbd2_revoke_table_s; 339 340 /** 341 * struct handle_s - The handle_s type is the concrete type associated with 342 * handle_t. 343 * @h_transaction: Which compound transaction is this update a part of? 344 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 345 * @h_ref: Reference count on this handle 346 * @h_err: Field for caller's use to track errors through large fs operations 347 * @h_sync: flag for sync-on-close 348 * @h_jdata: flag to force data journaling 349 * @h_aborted: flag indicating fatal error on handle 350 **/ 351 352 /* Docbook can't yet cope with the bit fields, but will leave the documentation 353 * in so it can be fixed later. 354 */ 355 356 struct jbd2_journal_handle 357 { 358 /* Which compound transaction is this update a part of? */ 359 transaction_t *h_transaction; 360 361 /* Number of remaining buffers we are allowed to dirty: */ 362 int h_buffer_credits; 363 364 /* Reference count on this handle */ 365 int h_ref; 366 367 /* Field for caller's use to track errors through large fs */ 368 /* operations */ 369 int h_err; 370 371 /* Flags [no locking] */ 372 unsigned int h_sync:1; /* sync-on-close */ 373 unsigned int h_jdata:1; /* force data journaling */ 374 unsigned int h_aborted:1; /* fatal error on handle */ 375 unsigned int h_cowing:1; /* COWing block to snapshot */ 376 377 /* Number of buffers requested by user: 378 * (before adding the COW credits factor) */ 379 unsigned int h_base_credits:14; 380 381 /* Number of buffers the user is allowed to dirty: 382 * (counts only buffers dirtied when !h_cowing) */ 383 unsigned int h_user_credits:14; 384 385 386 #ifdef CONFIG_DEBUG_LOCK_ALLOC 387 struct lockdep_map h_lockdep_map; 388 #endif 389 390 #ifdef CONFIG_JBD2_DEBUG 391 /* COW debugging counters: */ 392 unsigned int h_cow_moved; /* blocks moved to snapshot */ 393 unsigned int h_cow_copied; /* blocks copied to snapshot */ 394 unsigned int h_cow_ok_jh; /* blocks already COWed during current 395 transaction */ 396 unsigned int h_cow_ok_bitmap; /* blocks not set in COW bitmap */ 397 unsigned int h_cow_ok_mapped;/* blocks already mapped in snapshot */ 398 unsigned int h_cow_bitmaps; /* COW bitmaps created */ 399 unsigned int h_cow_excluded; /* blocks set in exclude bitmap */ 400 #endif 401 }; 402 403 404 /* 405 * Some stats for checkpoint phase 406 */ 407 struct transaction_chp_stats_s { 408 unsigned long cs_chp_time; 409 __u32 cs_forced_to_close; 410 __u32 cs_written; 411 __u32 cs_dropped; 412 }; 413 414 /* The transaction_t type is the guts of the journaling mechanism. It 415 * tracks a compound transaction through its various states: 416 * 417 * RUNNING: accepting new updates 418 * LOCKED: Updates still running but we don't accept new ones 419 * RUNDOWN: Updates are tidying up but have finished requesting 420 * new buffers to modify (state not used for now) 421 * FLUSH: All updates complete, but we are still writing to disk 422 * COMMIT: All data on disk, writing commit record 423 * FINISHED: We still have to keep the transaction for checkpointing. 424 * 425 * The transaction keeps track of all of the buffers modified by a 426 * running transaction, and all of the buffers committed but not yet 427 * flushed to home for finished transactions. 428 */ 429 430 /* 431 * Lock ranking: 432 * 433 * j_list_lock 434 * ->jbd_lock_bh_journal_head() (This is "innermost") 435 * 436 * j_state_lock 437 * ->jbd_lock_bh_state() 438 * 439 * jbd_lock_bh_state() 440 * ->j_list_lock 441 * 442 * j_state_lock 443 * ->t_handle_lock 444 * 445 * j_state_lock 446 * ->j_list_lock (journal_unmap_buffer) 447 * 448 */ 449 450 struct transaction_s 451 { 452 /* Pointer to the journal for this transaction. [no locking] */ 453 journal_t *t_journal; 454 455 /* Sequence number for this transaction [no locking] */ 456 tid_t t_tid; 457 458 /* 459 * Transaction's current state 460 * [no locking - only kjournald2 alters this] 461 * [j_list_lock] guards transition of a transaction into T_FINISHED 462 * state and subsequent call of __jbd2_journal_drop_transaction() 463 * FIXME: needs barriers 464 * KLUDGE: [use j_state_lock] 465 */ 466 enum { 467 T_RUNNING, 468 T_LOCKED, 469 T_FLUSH, 470 T_COMMIT, 471 T_COMMIT_DFLUSH, 472 T_COMMIT_JFLUSH, 473 T_FINISHED 474 } t_state; 475 476 /* 477 * Where in the log does this transaction's commit start? [no locking] 478 */ 479 unsigned long t_log_start; 480 481 /* Number of buffers on the t_buffers list [j_list_lock] */ 482 int t_nr_buffers; 483 484 /* 485 * Doubly-linked circular list of all buffers reserved but not yet 486 * modified by this transaction [j_list_lock] 487 */ 488 struct journal_head *t_reserved_list; 489 490 /* 491 * Doubly-linked circular list of all metadata buffers owned by this 492 * transaction [j_list_lock] 493 */ 494 struct journal_head *t_buffers; 495 496 /* 497 * Doubly-linked circular list of all forget buffers (superseded 498 * buffers which we can un-checkpoint once this transaction commits) 499 * [j_list_lock] 500 */ 501 struct journal_head *t_forget; 502 503 /* 504 * Doubly-linked circular list of all buffers still to be flushed before 505 * this transaction can be checkpointed. [j_list_lock] 506 */ 507 struct journal_head *t_checkpoint_list; 508 509 /* 510 * Doubly-linked circular list of all buffers submitted for IO while 511 * checkpointing. [j_list_lock] 512 */ 513 struct journal_head *t_checkpoint_io_list; 514 515 /* 516 * Doubly-linked circular list of temporary buffers currently undergoing 517 * IO in the log [j_list_lock] 518 */ 519 struct journal_head *t_iobuf_list; 520 521 /* 522 * Doubly-linked circular list of metadata buffers being shadowed by log 523 * IO. The IO buffers on the iobuf list and the shadow buffers on this 524 * list match each other one for one at all times. [j_list_lock] 525 */ 526 struct journal_head *t_shadow_list; 527 528 /* 529 * Doubly-linked circular list of control buffers being written to the 530 * log. [j_list_lock] 531 */ 532 struct journal_head *t_log_list; 533 534 /* 535 * List of inodes whose data we've modified in data=ordered mode. 536 * [j_list_lock] 537 */ 538 struct list_head t_inode_list; 539 540 /* 541 * Protects info related to handles 542 */ 543 spinlock_t t_handle_lock; 544 545 /* 546 * Longest time some handle had to wait for running transaction 547 */ 548 unsigned long t_max_wait; 549 550 /* 551 * When transaction started 552 */ 553 unsigned long t_start; 554 555 /* 556 * Checkpointing stats [j_checkpoint_sem] 557 */ 558 struct transaction_chp_stats_s t_chp_stats; 559 560 /* 561 * Number of outstanding updates running on this transaction 562 * [t_handle_lock] 563 */ 564 atomic_t t_updates; 565 566 /* 567 * Number of buffers reserved for use by all handles in this transaction 568 * handle but not yet modified. [t_handle_lock] 569 */ 570 atomic_t t_outstanding_credits; 571 572 /* 573 * Forward and backward links for the circular list of all transactions 574 * awaiting checkpoint. [j_list_lock] 575 */ 576 transaction_t *t_cpnext, *t_cpprev; 577 578 /* 579 * When will the transaction expire (become due for commit), in jiffies? 580 * [no locking] 581 */ 582 unsigned long t_expires; 583 584 /* 585 * When this transaction started, in nanoseconds [no locking] 586 */ 587 ktime_t t_start_time; 588 589 /* 590 * How many handles used this transaction? [t_handle_lock] 591 */ 592 atomic_t t_handle_count; 593 594 /* 595 * This transaction is being forced and some process is 596 * waiting for it to finish. 597 */ 598 unsigned int t_synchronous_commit:1; 599 600 /* Disk flush needs to be sent to fs partition [no locking] */ 601 int t_need_data_flush; 602 603 /* 604 * For use by the filesystem to store fs-specific data 605 * structures associated with the transaction 606 */ 607 struct list_head t_private_list; 608 }; 609 610 struct transaction_run_stats_s { 611 unsigned long rs_wait; 612 unsigned long rs_running; 613 unsigned long rs_locked; 614 unsigned long rs_flushing; 615 unsigned long rs_logging; 616 617 __u32 rs_handle_count; 618 __u32 rs_blocks; 619 __u32 rs_blocks_logged; 620 }; 621 622 struct transaction_stats_s { 623 unsigned long ts_tid; 624 struct transaction_run_stats_s run; 625 }; 626 627 static inline unsigned long 628 jbd2_time_diff(unsigned long start, unsigned long end) 629 { 630 if (end >= start) 631 return end - start; 632 633 return end + (MAX_JIFFY_OFFSET - start); 634 } 635 636 #define JBD2_NR_BATCH 64 637 638 /** 639 * struct journal_s - The journal_s type is the concrete type associated with 640 * journal_t. 641 * @j_flags: General journaling state flags 642 * @j_errno: Is there an outstanding uncleared error on the journal (from a 643 * prior abort)? 644 * @j_sb_buffer: First part of superblock buffer 645 * @j_superblock: Second part of superblock buffer 646 * @j_format_version: Version of the superblock format 647 * @j_state_lock: Protect the various scalars in the journal 648 * @j_barrier_count: Number of processes waiting to create a barrier lock 649 * @j_barrier: The barrier lock itself 650 * @j_running_transaction: The current running transaction.. 651 * @j_committing_transaction: the transaction we are pushing to disk 652 * @j_checkpoint_transactions: a linked circular list of all transactions 653 * waiting for checkpointing 654 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 655 * to start committing, or for a barrier lock to be released 656 * @j_wait_logspace: Wait queue for waiting for checkpointing to complete 657 * @j_wait_done_commit: Wait queue for waiting for commit to complete 658 * @j_wait_checkpoint: Wait queue to trigger checkpointing 659 * @j_wait_commit: Wait queue to trigger commit 660 * @j_wait_updates: Wait queue to wait for updates to complete 661 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 662 * @j_head: Journal head - identifies the first unused block in the journal 663 * @j_tail: Journal tail - identifies the oldest still-used block in the 664 * journal. 665 * @j_free: Journal free - how many free blocks are there in the journal? 666 * @j_first: The block number of the first usable block 667 * @j_last: The block number one beyond the last usable block 668 * @j_dev: Device where we store the journal 669 * @j_blocksize: blocksize for the location where we store the journal. 670 * @j_blk_offset: starting block offset for into the device where we store the 671 * journal 672 * @j_fs_dev: Device which holds the client fs. For internal journal this will 673 * be equal to j_dev 674 * @j_maxlen: Total maximum capacity of the journal region on disk. 675 * @j_list_lock: Protects the buffer lists and internal buffer state. 676 * @j_inode: Optional inode where we store the journal. If present, all journal 677 * block numbers are mapped into this inode via bmap(). 678 * @j_tail_sequence: Sequence number of the oldest transaction in the log 679 * @j_transaction_sequence: Sequence number of the next transaction to grant 680 * @j_commit_sequence: Sequence number of the most recently committed 681 * transaction 682 * @j_commit_request: Sequence number of the most recent transaction wanting 683 * commit 684 * @j_uuid: Uuid of client object. 685 * @j_task: Pointer to the current commit thread for this journal 686 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 687 * single compound commit transaction 688 * @j_commit_interval: What is the maximum transaction lifetime before we begin 689 * a commit? 690 * @j_commit_timer: The timer used to wakeup the commit thread 691 * @j_revoke_lock: Protect the revoke table 692 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 693 * current transaction. 694 * @j_revoke_table: alternate revoke tables for j_revoke 695 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 696 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 697 * number that will fit in j_blocksize 698 * @j_last_sync_writer: most recent pid which did a synchronous write 699 * @j_history: Buffer storing the transactions statistics history 700 * @j_history_max: Maximum number of transactions in the statistics history 701 * @j_history_cur: Current number of transactions in the statistics history 702 * @j_history_lock: Protect the transactions statistics history 703 * @j_proc_entry: procfs entry for the jbd statistics directory 704 * @j_stats: Overall statistics 705 * @j_private: An opaque pointer to fs-private information. 706 */ 707 708 struct journal_s 709 { 710 /* General journaling state flags [j_state_lock] */ 711 unsigned long j_flags; 712 713 /* 714 * Is there an outstanding uncleared error on the journal (from a prior 715 * abort)? [j_state_lock] 716 */ 717 int j_errno; 718 719 /* The superblock buffer */ 720 struct buffer_head *j_sb_buffer; 721 journal_superblock_t *j_superblock; 722 723 /* Version of the superblock format */ 724 int j_format_version; 725 726 /* 727 * Protect the various scalars in the journal 728 */ 729 rwlock_t j_state_lock; 730 731 /* 732 * Number of processes waiting to create a barrier lock [j_state_lock] 733 */ 734 int j_barrier_count; 735 736 /* The barrier lock itself */ 737 struct mutex j_barrier; 738 739 /* 740 * Transactions: The current running transaction... 741 * [j_state_lock] [caller holding open handle] 742 */ 743 transaction_t *j_running_transaction; 744 745 /* 746 * the transaction we are pushing to disk 747 * [j_state_lock] [caller holding open handle] 748 */ 749 transaction_t *j_committing_transaction; 750 751 /* 752 * ... and a linked circular list of all transactions waiting for 753 * checkpointing. [j_list_lock] 754 */ 755 transaction_t *j_checkpoint_transactions; 756 757 /* 758 * Wait queue for waiting for a locked transaction to start committing, 759 * or for a barrier lock to be released 760 */ 761 wait_queue_head_t j_wait_transaction_locked; 762 763 /* Wait queue for waiting for checkpointing to complete */ 764 wait_queue_head_t j_wait_logspace; 765 766 /* Wait queue for waiting for commit to complete */ 767 wait_queue_head_t j_wait_done_commit; 768 769 /* Wait queue to trigger checkpointing */ 770 wait_queue_head_t j_wait_checkpoint; 771 772 /* Wait queue to trigger commit */ 773 wait_queue_head_t j_wait_commit; 774 775 /* Wait queue to wait for updates to complete */ 776 wait_queue_head_t j_wait_updates; 777 778 /* Semaphore for locking against concurrent checkpoints */ 779 struct mutex j_checkpoint_mutex; 780 781 /* 782 * List of buffer heads used by the checkpoint routine. This 783 * was moved from jbd2_log_do_checkpoint() to reduce stack 784 * usage. Access to this array is controlled by the 785 * j_checkpoint_mutex. [j_checkpoint_mutex] 786 */ 787 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 788 789 /* 790 * Journal head: identifies the first unused block in the journal. 791 * [j_state_lock] 792 */ 793 unsigned long j_head; 794 795 /* 796 * Journal tail: identifies the oldest still-used block in the journal. 797 * [j_state_lock] 798 */ 799 unsigned long j_tail; 800 801 /* 802 * Journal free: how many free blocks are there in the journal? 803 * [j_state_lock] 804 */ 805 unsigned long j_free; 806 807 /* 808 * Journal start and end: the block numbers of the first usable block 809 * and one beyond the last usable block in the journal. [j_state_lock] 810 */ 811 unsigned long j_first; 812 unsigned long j_last; 813 814 /* 815 * Device, blocksize and starting block offset for the location where we 816 * store the journal. 817 */ 818 struct block_device *j_dev; 819 int j_blocksize; 820 unsigned long long j_blk_offset; 821 char j_devname[BDEVNAME_SIZE+24]; 822 823 /* 824 * Device which holds the client fs. For internal journal this will be 825 * equal to j_dev. 826 */ 827 struct block_device *j_fs_dev; 828 829 /* Total maximum capacity of the journal region on disk. */ 830 unsigned int j_maxlen; 831 832 /* 833 * Protects the buffer lists and internal buffer state. 834 */ 835 spinlock_t j_list_lock; 836 837 /* Optional inode where we store the journal. If present, all */ 838 /* journal block numbers are mapped into this inode via */ 839 /* bmap(). */ 840 struct inode *j_inode; 841 842 /* 843 * Sequence number of the oldest transaction in the log [j_state_lock] 844 */ 845 tid_t j_tail_sequence; 846 847 /* 848 * Sequence number of the next transaction to grant [j_state_lock] 849 */ 850 tid_t j_transaction_sequence; 851 852 /* 853 * Sequence number of the most recently committed transaction 854 * [j_state_lock]. 855 */ 856 tid_t j_commit_sequence; 857 858 /* 859 * Sequence number of the most recent transaction wanting commit 860 * [j_state_lock] 861 */ 862 tid_t j_commit_request; 863 864 /* 865 * Journal uuid: identifies the object (filesystem, LVM volume etc) 866 * backed by this journal. This will eventually be replaced by an array 867 * of uuids, allowing us to index multiple devices within a single 868 * journal and to perform atomic updates across them. 869 */ 870 __u8 j_uuid[16]; 871 872 /* Pointer to the current commit thread for this journal */ 873 struct task_struct *j_task; 874 875 /* 876 * Maximum number of metadata buffers to allow in a single compound 877 * commit transaction 878 */ 879 int j_max_transaction_buffers; 880 881 /* 882 * What is the maximum transaction lifetime before we begin a commit? 883 */ 884 unsigned long j_commit_interval; 885 886 /* The timer used to wakeup the commit thread: */ 887 struct timer_list j_commit_timer; 888 889 /* 890 * The revoke table: maintains the list of revoked blocks in the 891 * current transaction. [j_revoke_lock] 892 */ 893 spinlock_t j_revoke_lock; 894 struct jbd2_revoke_table_s *j_revoke; 895 struct jbd2_revoke_table_s *j_revoke_table[2]; 896 897 /* 898 * array of bhs for jbd2_journal_commit_transaction 899 */ 900 struct buffer_head **j_wbuf; 901 int j_wbufsize; 902 903 /* 904 * this is the pid of hte last person to run a synchronous operation 905 * through the journal 906 */ 907 pid_t j_last_sync_writer; 908 909 /* 910 * the average amount of time in nanoseconds it takes to commit a 911 * transaction to disk. [j_state_lock] 912 */ 913 u64 j_average_commit_time; 914 915 /* 916 * minimum and maximum times that we should wait for 917 * additional filesystem operations to get batched into a 918 * synchronous handle in microseconds 919 */ 920 u32 j_min_batch_time; 921 u32 j_max_batch_time; 922 923 /* This function is called when a transaction is closed */ 924 void (*j_commit_callback)(journal_t *, 925 transaction_t *); 926 927 /* 928 * Journal statistics 929 */ 930 spinlock_t j_history_lock; 931 struct proc_dir_entry *j_proc_entry; 932 struct transaction_stats_s j_stats; 933 934 /* Failed journal commit ID */ 935 unsigned int j_failed_commit; 936 937 /* 938 * An opaque pointer to fs-private information. ext3 puts its 939 * superblock pointer here 940 */ 941 void *j_private; 942 }; 943 944 /* 945 * Journal flag definitions 946 */ 947 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 948 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 949 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 950 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 951 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 952 #define JBD2_BARRIER 0x020 /* Use IDE barriers */ 953 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 954 * data write error in ordered 955 * mode */ 956 957 /* 958 * Function declarations for the journaling transaction and buffer 959 * management 960 */ 961 962 /* Filing buffers */ 963 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 964 extern void __jbd2_journal_refile_buffer(struct journal_head *); 965 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 966 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 967 extern void __journal_free_buffer(struct journal_head *bh); 968 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 969 extern void __journal_clean_data_list(transaction_t *transaction); 970 971 /* Log buffer allocation */ 972 extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); 973 int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 974 975 /* Commit management */ 976 extern void jbd2_journal_commit_transaction(journal_t *); 977 978 /* Checkpoint list management */ 979 int __jbd2_journal_clean_checkpoint_list(journal_t *journal); 980 int __jbd2_journal_remove_checkpoint(struct journal_head *); 981 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 982 983 984 /* 985 * Triggers 986 */ 987 988 struct jbd2_buffer_trigger_type { 989 /* 990 * Fired a the moment data to write to the journal are known to be 991 * stable - so either at the moment b_frozen_data is created or just 992 * before a buffer is written to the journal. mapped_data is a mapped 993 * buffer that is the frozen data for commit. 994 */ 995 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 996 struct buffer_head *bh, void *mapped_data, 997 size_t size); 998 999 /* 1000 * Fired during journal abort for dirty buffers that will not be 1001 * committed. 1002 */ 1003 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1004 struct buffer_head *bh); 1005 }; 1006 1007 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1008 void *mapped_data, 1009 struct jbd2_buffer_trigger_type *triggers); 1010 extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1011 struct jbd2_buffer_trigger_type *triggers); 1012 1013 /* Buffer IO */ 1014 extern int 1015 jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1016 struct journal_head *jh_in, 1017 struct journal_head **jh_out, 1018 unsigned long long blocknr); 1019 1020 /* Transaction locking */ 1021 extern void __wait_on_journal (journal_t *); 1022 1023 /* 1024 * Journal locking. 1025 * 1026 * We need to lock the journal during transaction state changes so that nobody 1027 * ever tries to take a handle on the running transaction while we are in the 1028 * middle of moving it to the commit phase. j_state_lock does this. 1029 * 1030 * Note that the locking is completely interrupt unsafe. We never touch 1031 * journal structures from interrupts. 1032 */ 1033 1034 static inline handle_t *journal_current_handle(void) 1035 { 1036 return current->journal_info; 1037 } 1038 1039 /* The journaling code user interface: 1040 * 1041 * Create and destroy handles 1042 * Register buffer modifications against the current transaction. 1043 */ 1044 1045 extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1046 extern handle_t *jbd2__journal_start(journal_t *, int nblocks, gfp_t gfp_mask); 1047 extern int jbd2_journal_restart(handle_t *, int nblocks); 1048 extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask); 1049 extern int jbd2_journal_extend (handle_t *, int nblocks); 1050 extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1051 extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1052 extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1053 void jbd2_journal_set_triggers(struct buffer_head *, 1054 struct jbd2_buffer_trigger_type *type); 1055 extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1056 extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); 1057 extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1058 extern void journal_sync_buffer (struct buffer_head *); 1059 extern void jbd2_journal_invalidatepage(journal_t *, 1060 struct page *, unsigned long); 1061 extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1062 extern int jbd2_journal_stop(handle_t *); 1063 extern int jbd2_journal_flush (journal_t *); 1064 extern void jbd2_journal_lock_updates (journal_t *); 1065 extern void jbd2_journal_unlock_updates (journal_t *); 1066 1067 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1068 struct block_device *fs_dev, 1069 unsigned long long start, int len, int bsize); 1070 extern journal_t * jbd2_journal_init_inode (struct inode *); 1071 extern int jbd2_journal_update_format (journal_t *); 1072 extern int jbd2_journal_check_used_features 1073 (journal_t *, unsigned long, unsigned long, unsigned long); 1074 extern int jbd2_journal_check_available_features 1075 (journal_t *, unsigned long, unsigned long, unsigned long); 1076 extern int jbd2_journal_set_features 1077 (journal_t *, unsigned long, unsigned long, unsigned long); 1078 extern void jbd2_journal_clear_features 1079 (journal_t *, unsigned long, unsigned long, unsigned long); 1080 extern int jbd2_journal_load (journal_t *journal); 1081 extern int jbd2_journal_destroy (journal_t *); 1082 extern int jbd2_journal_recover (journal_t *journal); 1083 extern int jbd2_journal_wipe (journal_t *, int); 1084 extern int jbd2_journal_skip_recovery (journal_t *); 1085 extern void jbd2_journal_update_superblock (journal_t *, int); 1086 extern void __jbd2_journal_abort_hard (journal_t *); 1087 extern void jbd2_journal_abort (journal_t *, int); 1088 extern int jbd2_journal_errno (journal_t *); 1089 extern void jbd2_journal_ack_err (journal_t *); 1090 extern int jbd2_journal_clear_err (journal_t *); 1091 extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1092 extern int jbd2_journal_force_commit(journal_t *); 1093 extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1094 extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1095 struct jbd2_inode *inode, loff_t new_size); 1096 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1097 extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1098 1099 /* 1100 * journal_head management 1101 */ 1102 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1103 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1104 void jbd2_journal_put_journal_head(struct journal_head *jh); 1105 1106 /* 1107 * handle management 1108 */ 1109 extern struct kmem_cache *jbd2_handle_cache; 1110 1111 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1112 { 1113 return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); 1114 } 1115 1116 static inline void jbd2_free_handle(handle_t *handle) 1117 { 1118 kmem_cache_free(jbd2_handle_cache, handle); 1119 } 1120 1121 /* 1122 * jbd2_inode management (optional, for those file systems that want to use 1123 * dynamically allocated jbd2_inode structures) 1124 */ 1125 extern struct kmem_cache *jbd2_inode_cache; 1126 1127 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1128 { 1129 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1130 } 1131 1132 static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1133 { 1134 kmem_cache_free(jbd2_inode_cache, jinode); 1135 } 1136 1137 /* Primary revoke support */ 1138 #define JOURNAL_REVOKE_DEFAULT_HASH 256 1139 extern int jbd2_journal_init_revoke(journal_t *, int); 1140 extern void jbd2_journal_destroy_revoke_caches(void); 1141 extern int jbd2_journal_init_revoke_caches(void); 1142 1143 extern void jbd2_journal_destroy_revoke(journal_t *); 1144 extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1145 extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1146 extern void jbd2_journal_write_revoke_records(journal_t *, 1147 transaction_t *, int); 1148 1149 /* Recovery revoke support */ 1150 extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1151 extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1152 extern void jbd2_journal_clear_revoke(journal_t *); 1153 extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1154 extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1155 1156 /* 1157 * The log thread user interface: 1158 * 1159 * Request space in the current transaction, and force transaction commit 1160 * transitions on demand. 1161 */ 1162 1163 int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ 1164 int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1165 int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1166 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1167 int jbd2_journal_force_commit_nested(journal_t *journal); 1168 int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1169 int jbd2_log_do_checkpoint(journal_t *journal); 1170 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 1171 1172 void __jbd2_log_wait_for_space(journal_t *journal); 1173 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1174 extern int jbd2_cleanup_journal_tail(journal_t *); 1175 1176 /* Debugging code only: */ 1177 1178 #define jbd_ENOSYS() \ 1179 do { \ 1180 printk (KERN_ERR "JBD unimplemented function %s\n", __func__); \ 1181 current->state = TASK_UNINTERRUPTIBLE; \ 1182 schedule(); \ 1183 } while (1) 1184 1185 /* 1186 * is_journal_abort 1187 * 1188 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1189 * bit, when set, indicates that we have had a fatal error somewhere, 1190 * either inside the journaling layer or indicated to us by the client 1191 * (eg. ext3), and that we and should not commit any further 1192 * transactions. 1193 */ 1194 1195 static inline int is_journal_aborted(journal_t *journal) 1196 { 1197 return journal->j_flags & JBD2_ABORT; 1198 } 1199 1200 static inline int is_handle_aborted(handle_t *handle) 1201 { 1202 if (handle->h_aborted) 1203 return 1; 1204 return is_journal_aborted(handle->h_transaction->t_journal); 1205 } 1206 1207 static inline void jbd2_journal_abort_handle(handle_t *handle) 1208 { 1209 handle->h_aborted = 1; 1210 } 1211 1212 #endif /* __KERNEL__ */ 1213 1214 /* Comparison functions for transaction IDs: perform comparisons using 1215 * modulo arithmetic so that they work over sequence number wraps. */ 1216 1217 static inline int tid_gt(tid_t x, tid_t y) 1218 { 1219 int difference = (x - y); 1220 return (difference > 0); 1221 } 1222 1223 static inline int tid_geq(tid_t x, tid_t y) 1224 { 1225 int difference = (x - y); 1226 return (difference >= 0); 1227 } 1228 1229 extern int jbd2_journal_blocks_per_page(struct inode *inode); 1230 extern size_t journal_tag_bytes(journal_t *journal); 1231 1232 /* 1233 * Return the minimum number of blocks which must be free in the journal 1234 * before a new transaction may be started. Must be called under j_state_lock. 1235 */ 1236 static inline int jbd_space_needed(journal_t *journal) 1237 { 1238 int nblocks = journal->j_max_transaction_buffers; 1239 if (journal->j_committing_transaction) 1240 nblocks += atomic_read(&journal->j_committing_transaction-> 1241 t_outstanding_credits); 1242 return nblocks; 1243 } 1244 1245 /* 1246 * Definitions which augment the buffer_head layer 1247 */ 1248 1249 /* journaling buffer types */ 1250 #define BJ_None 0 /* Not journaled */ 1251 #define BJ_Metadata 1 /* Normal journaled metadata */ 1252 #define BJ_Forget 2 /* Buffer superseded by this transaction */ 1253 #define BJ_IO 3 /* Buffer is for temporary IO use */ 1254 #define BJ_Shadow 4 /* Buffer contents being shadowed to the log */ 1255 #define BJ_LogCtl 5 /* Buffer contains log descriptors */ 1256 #define BJ_Reserved 6 /* Buffer is reserved for access by journal */ 1257 #define BJ_Types 7 1258 1259 extern int jbd_blocks_per_page(struct inode *inode); 1260 1261 #ifdef __KERNEL__ 1262 1263 #define buffer_trace_init(bh) do {} while (0) 1264 #define print_buffer_fields(bh) do {} while (0) 1265 #define print_buffer_trace(bh) do {} while (0) 1266 #define BUFFER_TRACE(bh, info) do {} while (0) 1267 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1268 #define JBUFFER_TRACE(jh, info) do {} while (0) 1269 1270 #endif /* __KERNEL__ */ 1271 1272 #endif /* _LINUX_JBD2_H */ 1273