linux/include/linux/jbd2.h
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   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
  60extern 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
  74extern void *jbd2_alloc(size_t size, gfp_t flags);
  75extern 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 **/
  98typedef 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 **/
 112typedef 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 */
 138typedef 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 */
 170struct 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 */
 188typedef 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 */
 200struct 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 */
 208typedef 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 */
 215struct 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 */
 229typedef 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 */
 346struct 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
 366struct 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
 384struct 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 */
 435struct 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
 478struct 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
 638struct 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
 650struct transaction_stats_s {
 651        unsigned long           ts_tid;
 652        struct transaction_run_stats_s run;
 653};
 654
 655static inline unsigned long
 656jbd2_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
 736struct 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 */
 997extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
 998extern void __jbd2_journal_refile_buffer(struct journal_head *);
 999extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1000extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1001extern void __journal_free_buffer(struct journal_head *bh);
1002extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1003extern void __journal_clean_data_list(transaction_t *transaction);
1004
1005/* Log buffer allocation */
1006extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *);
1007int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1008int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1009                              unsigned long *block);
1010void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1011void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1012
1013/* Commit management */
1014extern void jbd2_journal_commit_transaction(journal_t *);
1015
1016/* Checkpoint list management */
1017int __jbd2_journal_clean_checkpoint_list(journal_t *journal);
1018int __jbd2_journal_remove_checkpoint(struct journal_head *);
1019void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1020
1021
1022/*
1023 * Triggers
1024 */
1025
1026struct 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
1045extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1046                                       void *mapped_data,
1047                                       struct jbd2_buffer_trigger_type *triggers);
1048extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1049                                      struct jbd2_buffer_trigger_type *triggers);
1050
1051/* Buffer IO */
1052extern int
1053jbd2_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 */
1059extern void             __wait_on_journal (journal_t *);
1060
1061/* Transaction cache support */
1062extern void jbd2_journal_destroy_transaction_cache(void);
1063extern int  jbd2_journal_init_transaction_cache(void);
1064extern 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
1077static 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
1088extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1089extern handle_t *jbd2__journal_start(journal_t *, int nblocks, gfp_t gfp_mask);
1090extern int       jbd2_journal_restart(handle_t *, int nblocks);
1091extern int       jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask);
1092extern int       jbd2_journal_extend (handle_t *, int nblocks);
1093extern int       jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1094extern int       jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1095extern int       jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1096void             jbd2_journal_set_triggers(struct buffer_head *,
1097                                           struct jbd2_buffer_trigger_type *type);
1098extern int       jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1099extern void      jbd2_journal_release_buffer (handle_t *, struct buffer_head *);
1100extern int       jbd2_journal_forget (handle_t *, struct buffer_head *);
1101extern void      journal_sync_buffer (struct buffer_head *);
1102extern void      jbd2_journal_invalidatepage(journal_t *,
1103                                struct page *, unsigned long);
1104extern int       jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t);
1105extern int       jbd2_journal_stop(handle_t *);
1106extern int       jbd2_journal_flush (journal_t *);
1107extern void      jbd2_journal_lock_updates (journal_t *);
1108extern void      jbd2_journal_unlock_updates (journal_t *);
1109
1110extern 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);
1113extern journal_t * jbd2_journal_init_inode (struct inode *);
1114extern int         jbd2_journal_update_format (journal_t *);
1115extern int         jbd2_journal_check_used_features
1116                   (journal_t *, unsigned long, unsigned long, unsigned long);
1117extern int         jbd2_journal_check_available_features
1118                   (journal_t *, unsigned long, unsigned long, unsigned long);
1119extern int         jbd2_journal_set_features
1120                   (journal_t *, unsigned long, unsigned long, unsigned long);
1121extern void        jbd2_journal_clear_features
1122                   (journal_t *, unsigned long, unsigned long, unsigned long);
1123extern int         jbd2_journal_load       (journal_t *journal);
1124extern int         jbd2_journal_destroy    (journal_t *);
1125extern int         jbd2_journal_recover    (journal_t *journal);
1126extern int         jbd2_journal_wipe       (journal_t *, int);
1127extern int         jbd2_journal_skip_recovery   (journal_t *);
1128extern void        jbd2_journal_update_sb_errno(journal_t *);
1129extern void        jbd2_journal_update_sb_log_tail      (journal_t *, tid_t,
1130                                unsigned long, int);
1131extern void        __jbd2_journal_abort_hard    (journal_t *);
1132extern void        jbd2_journal_abort      (journal_t *, int);
1133extern int         jbd2_journal_errno      (journal_t *);
1134extern void        jbd2_journal_ack_err    (journal_t *);
1135extern int         jbd2_journal_clear_err  (journal_t *);
1136extern int         jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1137extern int         jbd2_journal_force_commit(journal_t *);
1138extern int         jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode);
1139extern int         jbd2_journal_begin_ordered_truncate(journal_t *journal,
1140                                struct jbd2_inode *inode, loff_t new_size);
1141extern void        jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1142extern void        jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1143
1144/*
1145 * journal_head management
1146 */
1147struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1148struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1149void jbd2_journal_put_journal_head(struct journal_head *jh);
1150
1151/*
1152 * handle management
1153 */
1154extern struct kmem_cache *jbd2_handle_cache;
1155
1156static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1157{
1158        return kmem_cache_alloc(jbd2_handle_cache, gfp_flags);
1159}
1160
1161static 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 */
1170extern struct kmem_cache *jbd2_inode_cache;
1171
1172static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1173{
1174        return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
1175}
1176
1177static 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
1184extern int         jbd2_journal_init_revoke(journal_t *, int);
1185extern void        jbd2_journal_destroy_revoke_caches(void);
1186extern int         jbd2_journal_init_revoke_caches(void);
1187
1188extern void        jbd2_journal_destroy_revoke(journal_t *);
1189extern int         jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1190extern int         jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1191extern void        jbd2_journal_write_revoke_records(journal_t *,
1192                                                     transaction_t *, int);
1193
1194/* Recovery revoke support */
1195extern int      jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1196extern int      jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1197extern void     jbd2_journal_clear_revoke(journal_t *);
1198extern void     jbd2_journal_switch_revoke_table(journal_t *journal);
1199extern 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
1208int __jbd2_log_space_left(journal_t *); /* Called with journal locked */
1209int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1210int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
1211int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1212int jbd2_journal_force_commit_nested(journal_t *journal);
1213int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1214int jbd2_log_do_checkpoint(journal_t *journal);
1215int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1216
1217void __jbd2_log_wait_for_space(journal_t *journal);
1218extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1219extern int jbd2_cleanup_journal_tail(journal_t *);
1220
1221/* Debugging code only: */
1222
1223#define jbd_ENOSYS() \
1224do {                                                                       \
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
1240static inline int is_journal_aborted(journal_t *journal)
1241{
1242        return journal->j_flags & JBD2_ABORT;
1243}
1244
1245static 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
1252static 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
1262static inline int tid_gt(tid_t x, tid_t y)
1263{
1264        int difference = (x - y);
1265        return (difference > 0);
1266}
1267
1268static inline int tid_geq(tid_t x, tid_t y)
1269{
1270        int difference = (x - y);
1271        return (difference >= 0);
1272}
1273
1274extern int jbd2_journal_blocks_per_page(struct inode *inode);
1275extern 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 */
1281static 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
1304extern int jbd_blocks_per_page(struct inode *inode);
1305
1306static 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
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