fs/ext4/ext4_jbd2.h

   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 inode+data */
  90 #define EXT4_QUOTA_TRANS_BLOCKS(sb) (test_opt(sb, QUOTA) ? 2 : 0)
  91 /* Amount of blocks needed for quota insert/delete - we do some block writes
  92  * but inode, sb and group updates are done only once */
  93 #define EXT4_QUOTA_INIT_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_INIT_ALLOC*\
  94                 (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_INIT_REWRITE) : 0)
  95
  96 #define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\
  97                 (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0)
  98 #else
  99 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
 100 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
 101 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
 102 #endif
 103 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
 104 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
 105 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
 106
 107 int
 108 ext4_mark_iloc_dirty(handle_t *handle,
 109                      struct inode *inode,
 110                      struct ext4_iloc *iloc);
 111
 112 /*
 113  * On success, We end up with an outstanding reference count against
 114  * iloc->bh.  This _must_ be cleaned up later.
 115  */
 116
 117 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 118                         struct ext4_iloc *iloc);
 119
 120 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
 121
 122 /*
 123  * Wrapper functions with which ext4 calls into JBD.
 124  */
 125 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 126                 struct buffer_head *bh, handle_t *handle, int err);
 127
 128 int __ext4_journal_get_undo_access(const char *where, handle_t *handle,
 129                                 struct buffer_head *bh);
 130
 131 int __ext4_journal_get_write_access(const char *where, handle_t *handle,
 132                                 struct buffer_head *bh);
 133
 134 int __ext4_forget(const char *where, handle_t *handle, int is_metadata,
 135                   struct inode *inode, struct buffer_head *bh,
 136                   ext4_fsblk_t blocknr);
 137
 138 int __ext4_journal_get_create_access(const char *where,
 139                                 handle_t *handle, struct buffer_head *bh);
 140
 141 int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,
 142                                  struct inode *inode, struct buffer_head *bh);
 143
 144 #define ext4_journal_get_undo_access(handle, bh) \
 145         __ext4_journal_get_undo_access(__func__, (handle), (bh))
 146 #define ext4_journal_get_write_access(handle, bh) \
 147         __ext4_journal_get_write_access(__func__, (handle), (bh))
 148 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
 149         __ext4_forget(__func__, (handle), (is_metadata), (inode), (bh),\
 150                       (block_nr))
 151 #define ext4_journal_get_create_access(handle, bh) \
 152         __ext4_journal_get_create_access(__func__, (handle), (bh))
 153 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 154         __ext4_handle_dirty_metadata(__func__, (handle), (inode), (bh))
 155
 156 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 157 int __ext4_journal_stop(const char *where, handle_t *handle);
 158
 159 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
 160
 161 /* Note:  Do not use this for NULL handles.  This is only to determine if
 162  * a properly allocated handle is using a journal or not. */
 163 static inline int ext4_handle_valid(handle_t *handle)
 164 {
 165         if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
 166                 return 0;
 167         return 1;
 168 }
 169
 170 static inline void ext4_handle_sync(handle_t *handle)
 171 {
 172         if (ext4_handle_valid(handle))
 173                 handle->h_sync = 1;
 174 }
 175
 176 static inline void ext4_handle_release_buffer(handle_t *handle,
 177                                                 struct buffer_head *bh)
 178 {
 179         if (ext4_handle_valid(handle))
 180                 jbd2_journal_release_buffer(handle, bh);
 181 }
 182
 183 static inline int ext4_handle_is_aborted(handle_t *handle)
 184 {
 185         if (ext4_handle_valid(handle))
 186                 return is_handle_aborted(handle);
 187         return 0;
 188 }
 189
 190 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
 191 {
 192         if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
 193                 return 0;
 194         return 1;
 195 }
 196
 197 static inline void ext4_journal_release_buffer(handle_t *handle,
 198                                                 struct buffer_head *bh)
 199 {
 200         if (ext4_handle_valid(handle))
 201                 jbd2_journal_release_buffer(handle, bh);
 202 }
 203
 204 static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
 205 {
 206         return ext4_journal_start_sb(inode->i_sb, nblocks);
 207 }
 208
 209 #define ext4_journal_stop(handle) \
 210         __ext4_journal_stop(__func__, (handle))
 211
 212 static inline handle_t *ext4_journal_current_handle(void)
 213 {
 214         return journal_current_handle();
 215 }
 216
 217 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 218 {
 219         if (ext4_handle_valid(handle))
 220                 return jbd2_journal_extend(handle, nblocks);
 221         return 0;
 222 }
 223
 224 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 225 {
 226         if (ext4_handle_valid(handle))
 227                 return jbd2_journal_restart(handle, nblocks);
 228         return 0;
 229 }
 230
 231 static inline int ext4_journal_blocks_per_page(struct inode *inode)
 232 {
 233         if (EXT4_JOURNAL(inode) != NULL)
 234                 return jbd2_journal_blocks_per_page(inode);
 235         return 0;
 236 }
 237
 238 static inline int ext4_journal_force_commit(journal_t *journal)
 239 {
 240         if (journal)
 241                 return jbd2_journal_force_commit(journal);
 242         return 0;
 243 }
 244
 245 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
 246 {
 247         if (ext4_handle_valid(handle))
 248                 return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
 249         return 0;
 250 }
 251
 252 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
 253                                                  struct inode *inode,
 254                                                  int datasync)
 255 {
 256         struct ext4_inode_info *ei = EXT4_I(inode);
 257
 258         if (ext4_handle_valid(handle)) {
 259                 ei->i_sync_tid = handle->h_transaction->t_tid;
 260                 if (datasync)
 261                         ei->i_datasync_tid = handle->h_transaction->t_tid;
 262         }
 263 }
 264
 265 /* super.c */
 266 int ext4_force_commit(struct super_block *sb);
 267
 268 static inline int ext4_should_journal_data(struct inode *inode)
 269 {
 270         if (EXT4_JOURNAL(inode) == NULL)
 271                 return 0;
 272         if (!S_ISREG(inode->i_mode))
 273                 return 1;
 274         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 275                 return 1;
 276         if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA))
 277                 return 1;
 278         return 0;
 279 }
 280
 281 static inline int ext4_should_order_data(struct inode *inode)
 282 {
 283         if (EXT4_JOURNAL(inode) == NULL)
 284                 return 0;
 285         if (!S_ISREG(inode->i_mode))
 286                 return 0;
 287         if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA))
 288                 return 0;
 289         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 290                 return 1;
 291         return 0;
 292 }
 293
 294 static inline int ext4_should_writeback_data(struct inode *inode)
 295 {
 296         if (!S_ISREG(inode->i_mode))
 297                 return 0;
 298         if (EXT4_JOURNAL(inode) == NULL)
 299                 return 1;
 300         if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA))
 301                 return 0;
 302         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 303                 return 1;
 304         return 0;
 305 }
 306
 307 /*
 308  * This function controls whether or not we should try to go down the
 309  * dioread_nolock code paths, which makes it safe to avoid taking
 310  * i_mutex for direct I/O reads.  This only works for extent-based
 311  * files, and it doesn't work for nobh or if data journaling is
 312  * enabled, since the dioread_nolock code uses b_private to pass
 313  * information back to the I/O completion handler, and this conflicts
 314  * with the jbd's use of b_private.
 315  */
 316 static inline int ext4_should_dioread_nolock(struct inode *inode)
 317 {
 318         if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
 319                 return 0;
 320         if (test_opt(inode->i_sb, NOBH))
 321                 return 0;
 322         if (!S_ISREG(inode->i_mode))
 323                 return 0;
 324         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 325                 return 0;
 326         if (ext4_should_journal_data(inode))
 327                 return 0;
 328         return 1;
 329 }
 330
 331 #endif  /* _EXT4_JBD2_H */