linux/fs/ext4/ext4_jbd2.h
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   1/*
   2 * ext4_jbd2.h
   3 *
   4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
   5 *
   6 * Copyright 1998--1999 Red Hat corp --- 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 * Ext4-specific journaling extensions.
  13 */
  14
  15#ifndef _EXT4_JBD2_H
  16#define _EXT4_JBD2_H
  17
  18#include <linux/fs.h>
  19#include <linux/jbd2.h>
  20#include "ext4.h"
  21
  22#define EXT4_JOURNAL(inode)     (EXT4_SB((inode)->i_sb)->s_journal)
  23
  24/* Define the number of blocks we need to account to a transaction to
  25 * modify one block of data.
  26 *
  27 * We may have to touch one inode, one bitmap buffer, up to three
  28 * indirection blocks, the group and superblock summaries, and the data
  29 * block to complete the transaction.
  30 *
  31 * For extents-enabled fs we may have to allocate and modify up to
  32 * 5 levels of tree + root which are stored in the inode. */
  33
  34#define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)                                \
  35        (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)   \
  36         ? 27U : 8U)
  37
  38/* Extended attribute operations touch at most two data buffers,
  39 * two bitmap buffers, and two group summaries, in addition to the inode
  40 * and the superblock, which are already accounted for. */
  41
  42#define EXT4_XATTR_TRANS_BLOCKS         6U
  43
  44/* Define the minimum size for a transaction which modifies data.  This
  45 * needs to take into account the fact that we may end up modifying two
  46 * quota files too (one for the group, one for the user quota).  The
  47 * superblock only gets updated once, of course, so don't bother
  48 * counting that again for the quota updates. */
  49
  50#define EXT4_DATA_TRANS_BLOCKS(sb)      (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
  51                                         EXT4_XATTR_TRANS_BLOCKS - 2 + \
  52                                         EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  53
  54/*
  55 * Define the number of metadata blocks we need to account to modify data.
  56 *
  57 * This include super block, inode block, quota blocks and xattr blocks
  58 */
  59#define EXT4_META_TRANS_BLOCKS(sb)      (EXT4_XATTR_TRANS_BLOCKS + \
  60                                        EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  61
  62/* Delete operations potentially hit one directory's namespace plus an
  63 * entire inode, plus arbitrary amounts of bitmap/indirection data.  Be
  64 * generous.  We can grow the delete transaction later if necessary. */
  65
  66#define EXT4_DELETE_TRANS_BLOCKS(sb)    (2 * EXT4_DATA_TRANS_BLOCKS(sb) + 64)
  67
  68/* Define an arbitrary limit for the amount of data we will anticipate
  69 * writing to any given transaction.  For unbounded transactions such as
  70 * write(2) and truncate(2) we can write more than this, but we always
  71 * start off at the maximum transaction size and grow the transaction
  72 * optimistically as we go. */
  73
  74#define EXT4_MAX_TRANS_DATA             64U
  75
  76/* We break up a large truncate or write transaction once the handle's
  77 * buffer credits gets this low, we need either to extend the
  78 * transaction or to start a new one.  Reserve enough space here for
  79 * inode, bitmap, superblock, group and indirection updates for at least
  80 * one block, plus two quota updates.  Quota allocations are not
  81 * needed. */
  82
  83#define EXT4_RESERVE_TRANS_BLOCKS       12U
  84
  85#define EXT4_INDEX_EXTRA_TRANS_BLOCKS   8
  86
  87#ifdef CONFIG_QUOTA
  88/* Amount of blocks needed for quota update - we know that the structure was
  89 * allocated so we need to update only data block */
  90#define EXT4_QUOTA_TRANS_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  91                EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
  92                1 : 0)
  93/* Amount of blocks needed for quota insert/delete - we do some block writes
  94 * but inode, sb and group updates are done only once */
  95#define EXT4_QUOTA_INIT_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  96                EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
  97                (DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
  98                 +3+DQUOT_INIT_REWRITE) : 0)
  99
 100#define EXT4_QUOTA_DEL_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
 101                EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
 102                (DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
 103                 +3+DQUOT_DEL_REWRITE) : 0)
 104#else
 105#define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
 106#define EXT4_QUOTA_INIT_BLOCKS(sb) 0
 107#define EXT4_QUOTA_DEL_BLOCKS(sb) 0
 108#endif
 109#define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
 110#define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
 111#define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
 112
 113/**
 114 *   struct ext4_journal_cb_entry - Base structure for callback information.
 115 *
 116 *   This struct is a 'seed' structure for a using with your own callback
 117 *   structs. If you are using callbacks you must allocate one of these
 118 *   or another struct of your own definition which has this struct
 119 *   as it's first element and pass it to ext4_journal_callback_add().
 120 */
 121struct ext4_journal_cb_entry {
 122        /* list information for other callbacks attached to the same handle */
 123        struct list_head jce_list;
 124
 125        /*  Function to call with this callback structure */
 126        void (*jce_func)(struct super_block *sb,
 127                         struct ext4_journal_cb_entry *jce, int error);
 128
 129        /* user data goes here */
 130};
 131
 132/**
 133 * ext4_journal_callback_add: add a function to call after transaction commit
 134 * @handle: active journal transaction handle to register callback on
 135 * @func: callback function to call after the transaction has committed:
 136 *        @sb: superblock of current filesystem for transaction
 137 *        @jce: returned journal callback data
 138 *        @rc: journal state at commit (0 = transaction committed properly)
 139 * @jce: journal callback data (internal and function private data struct)
 140 *
 141 * The registered function will be called in the context of the journal thread
 142 * after the transaction for which the handle was created has completed.
 143 *
 144 * No locks are held when the callback function is called, so it is safe to
 145 * call blocking functions from within the callback, but the callback should
 146 * not block or run for too long, or the filesystem will be blocked waiting for
 147 * the next transaction to commit. No journaling functions can be used, or
 148 * there is a risk of deadlock.
 149 *
 150 * There is no guaranteed calling order of multiple registered callbacks on
 151 * the same transaction.
 152 */
 153static inline void ext4_journal_callback_add(handle_t *handle,
 154                        void (*func)(struct super_block *sb,
 155                                     struct ext4_journal_cb_entry *jce,
 156                                     int rc),
 157                        struct ext4_journal_cb_entry *jce)
 158{
 159        struct ext4_sb_info *sbi =
 160                        EXT4_SB(handle->h_transaction->t_journal->j_private);
 161
 162        /* Add the jce to transaction's private list */
 163        jce->jce_func = func;
 164        spin_lock(&sbi->s_md_lock);
 165        list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
 166        spin_unlock(&sbi->s_md_lock);
 167}
 168
 169/**
 170 * ext4_journal_callback_del: delete a registered callback
 171 * @handle: active journal transaction handle on which callback was registered
 172 * @jce: registered journal callback entry to unregister
 173 */
 174static inline void ext4_journal_callback_del(handle_t *handle,
 175                                             struct ext4_journal_cb_entry *jce)
 176{
 177        struct ext4_sb_info *sbi =
 178                        EXT4_SB(handle->h_transaction->t_journal->j_private);
 179
 180        spin_lock(&sbi->s_md_lock);
 181        list_del_init(&jce->jce_list);
 182        spin_unlock(&sbi->s_md_lock);
 183}
 184
 185int
 186ext4_mark_iloc_dirty(handle_t *handle,
 187                     struct inode *inode,
 188                     struct ext4_iloc *iloc);
 189
 190/*
 191 * On success, We end up with an outstanding reference count against
 192 * iloc->bh.  This _must_ be cleaned up later.
 193 */
 194
 195int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 196                        struct ext4_iloc *iloc);
 197
 198int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
 199
 200/*
 201 * Wrapper functions with which ext4 calls into JBD.
 202 */
 203void ext4_journal_abort_handle(const char *caller, unsigned int line,
 204                               const char *err_fn,
 205                struct buffer_head *bh, handle_t *handle, int err);
 206
 207int __ext4_journal_get_write_access(const char *where, unsigned int line,
 208                                    handle_t *handle, struct buffer_head *bh);
 209
 210int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 211                  int is_metadata, struct inode *inode,
 212                  struct buffer_head *bh, ext4_fsblk_t blocknr);
 213
 214int __ext4_journal_get_create_access(const char *where, unsigned int line,
 215                                handle_t *handle, struct buffer_head *bh);
 216
 217int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 218                                 handle_t *handle, struct inode *inode,
 219                                 struct buffer_head *bh);
 220
 221int __ext4_handle_dirty_super(const char *where, unsigned int line,
 222                              handle_t *handle, struct super_block *sb);
 223
 224#define ext4_journal_get_write_access(handle, bh) \
 225        __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
 226#define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
 227        __ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
 228                      (bh), (block_nr))
 229#define ext4_journal_get_create_access(handle, bh) \
 230        __ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
 231#define ext4_handle_dirty_metadata(handle, inode, bh) \
 232        __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 233                                     (bh))
 234#define ext4_handle_dirty_super(handle, sb) \
 235        __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
 236
 237handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 238int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
 239
 240#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
 241
 242/* Note:  Do not use this for NULL handles.  This is only to determine if
 243 * a properly allocated handle is using a journal or not. */
 244static inline int ext4_handle_valid(handle_t *handle)
 245{
 246        if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
 247                return 0;
 248        return 1;
 249}
 250
 251static inline void ext4_handle_sync(handle_t *handle)
 252{
 253        if (ext4_handle_valid(handle))
 254                handle->h_sync = 1;
 255}
 256
 257static inline void ext4_handle_release_buffer(handle_t *handle,
 258                                                struct buffer_head *bh)
 259{
 260        if (ext4_handle_valid(handle))
 261                jbd2_journal_release_buffer(handle, bh);
 262}
 263
 264static inline int ext4_handle_is_aborted(handle_t *handle)
 265{
 266        if (ext4_handle_valid(handle))
 267                return is_handle_aborted(handle);
 268        return 0;
 269}
 270
 271static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
 272{
 273        if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
 274                return 0;
 275        return 1;
 276}
 277
 278static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
 279{
 280        return ext4_journal_start_sb(inode->i_sb, nblocks);
 281}
 282
 283#define ext4_journal_stop(handle) \
 284        __ext4_journal_stop(__func__, __LINE__, (handle))
 285
 286static inline handle_t *ext4_journal_current_handle(void)
 287{
 288        return journal_current_handle();
 289}
 290
 291static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 292{
 293        if (ext4_handle_valid(handle))
 294                return jbd2_journal_extend(handle, nblocks);
 295        return 0;
 296}
 297
 298static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 299{
 300        if (ext4_handle_valid(handle))
 301                return jbd2_journal_restart(handle, nblocks);
 302        return 0;
 303}
 304
 305static inline int ext4_journal_blocks_per_page(struct inode *inode)
 306{
 307        if (EXT4_JOURNAL(inode) != NULL)
 308                return jbd2_journal_blocks_per_page(inode);
 309        return 0;
 310}
 311
 312static inline int ext4_journal_force_commit(journal_t *journal)
 313{
 314        if (journal)
 315                return jbd2_journal_force_commit(journal);
 316        return 0;
 317}
 318
 319static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
 320{
 321        if (ext4_handle_valid(handle))
 322                return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode);
 323        return 0;
 324}
 325
 326static inline void ext4_update_inode_fsync_trans(handle_t *handle,
 327                                                 struct inode *inode,
 328                                                 int datasync)
 329{
 330        struct ext4_inode_info *ei = EXT4_I(inode);
 331
 332        if (ext4_handle_valid(handle)) {
 333                ei->i_sync_tid = handle->h_transaction->t_tid;
 334                if (datasync)
 335                        ei->i_datasync_tid = handle->h_transaction->t_tid;
 336        }
 337}
 338
 339/* super.c */
 340int ext4_force_commit(struct super_block *sb);
 341
 342/*
 343 * Ext4 inode journal modes
 344 */
 345#define EXT4_INODE_JOURNAL_DATA_MODE    0x01 /* journal data mode */
 346#define EXT4_INODE_ORDERED_DATA_MODE    0x02 /* ordered data mode */
 347#define EXT4_INODE_WRITEBACK_DATA_MODE  0x04 /* writeback data mode */
 348
 349static inline int ext4_inode_journal_mode(struct inode *inode)
 350{
 351        if (EXT4_JOURNAL(inode) == NULL)
 352                return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 353        /* We do not support data journalling with delayed allocation */
 354        if (!S_ISREG(inode->i_mode) ||
 355            test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 356                return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
 357        if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
 358            !test_opt(inode->i_sb, DELALLOC))
 359                return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
 360        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 361                return EXT4_INODE_ORDERED_DATA_MODE;    /* ordered */
 362        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 363                return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 364        else
 365                BUG();
 366}
 367
 368static inline int ext4_should_journal_data(struct inode *inode)
 369{
 370        return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
 371}
 372
 373static inline int ext4_should_order_data(struct inode *inode)
 374{
 375        return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
 376}
 377
 378static inline int ext4_should_writeback_data(struct inode *inode)
 379{
 380        return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
 381}
 382
 383/*
 384 * This function controls whether or not we should try to go down the
 385 * dioread_nolock code paths, which makes it safe to avoid taking
 386 * i_mutex for direct I/O reads.  This only works for extent-based
 387 * files, and it doesn't work if data journaling is enabled, since the
 388 * dioread_nolock code uses b_private to pass information back to the
 389 * I/O completion handler, and this conflicts with the jbd's use of
 390 * b_private.
 391 */
 392static inline int ext4_should_dioread_nolock(struct inode *inode)
 393{
 394        if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
 395                return 0;
 396        if (!S_ISREG(inode->i_mode))
 397                return 0;
 398        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 399                return 0;
 400        if (ext4_should_journal_data(inode))
 401                return 0;
 402        return 1;
 403}
 404
 405#endif  /* _EXT4_JBD2_H */
 406
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