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                                          2*EXT4_QUOTA_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                                         2*EXT4_QUOTA_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 #define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\
  96                 (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0)
  97 #else
  98 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
  99 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
 100 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
 101 #endif
 102
 103 int
 104 ext4_mark_iloc_dirty(handle_t *handle,
 105                      struct inode *inode,
 106                      struct ext4_iloc *iloc);
 107
 108 /*
 109  * On success, We end up with an outstanding reference count against
 110  * iloc->bh.  This _must_ be cleaned up later.
 111  */
 112
 113 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 114                         struct ext4_iloc *iloc);
 115
 116 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
 117
 118 /*
 119  * Wrapper functions with which ext4 calls into JBD.  The intent here is
 120  * to allow these to be turned into appropriate stubs so ext4 can control
 121  * ext2 filesystems, so ext2+ext4 systems only nee one fs.  This work hasn't
 122  * been done yet.
 123  */
 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 /* When called with an invalid handle, this will still do a put on the BH */
 135 int __ext4_journal_forget(const char *where, handle_t *handle,
 136                                 struct buffer_head *bh);
 137
 138 /* When called with an invalid handle, this will still do a put on the BH */
 139 int __ext4_journal_revoke(const char *where, handle_t *handle,
 140                                 ext4_fsblk_t blocknr, struct buffer_head *bh);
 141
 142 int __ext4_journal_get_create_access(const char *where,
 143                                 handle_t *handle, struct buffer_head *bh);
 144
 145 int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,
 146                                  struct inode *inode, struct buffer_head *bh);
 147
 148 #define ext4_journal_get_undo_access(handle, bh) \
 149         __ext4_journal_get_undo_access(__func__, (handle), (bh))
 150 #define ext4_journal_get_write_access(handle, bh) \
 151         __ext4_journal_get_write_access(__func__, (handle), (bh))
 152 #define ext4_journal_revoke(handle, blocknr, bh) \
 153         __ext4_journal_revoke(__func__, (handle), (blocknr), (bh))
 154 #define ext4_journal_get_create_access(handle, bh) \
 155         __ext4_journal_get_create_access(__func__, (handle), (bh))
 156 #define ext4_journal_forget(handle, bh) \
 157         __ext4_journal_forget(__func__, (handle), (bh))
 158 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 159         __ext4_handle_dirty_metadata(__func__, (handle), (inode), (bh))
 160
 161 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 162 int __ext4_journal_stop(const char *where, handle_t *handle);
 163
 164 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
 165
 166 /* Note:  Do not use this for NULL handles.  This is only to determine if
 167  * a properly allocated handle is using a journal or not. */
 168 static inline int ext4_handle_valid(handle_t *handle)
 169 {
 170         if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
 171                 return 0;
 172         return 1;
 173 }
 174
 175 static inline void ext4_handle_sync(handle_t *handle)
 176 {
 177         if (ext4_handle_valid(handle))
 178                 handle->h_sync = 1;
 179 }
 180
 181 static inline void ext4_handle_release_buffer(handle_t *handle,
 182                                                 struct buffer_head *bh)
 183 {
 184         if (ext4_handle_valid(handle))
 185                 jbd2_journal_release_buffer(handle, bh);
 186 }
 187
 188 static inline int ext4_handle_is_aborted(handle_t *handle)
 189 {
 190         if (ext4_handle_valid(handle))
 191                 return is_handle_aborted(handle);
 192         return 0;
 193 }
 194
 195 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
 196 {
 197         if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
 198                 return 0;
 199         return 1;
 200 }
 201
 202 static inline void ext4_journal_release_buffer(handle_t *handle,
 203                                                 struct buffer_head *bh)
 204 {
 205         if (ext4_handle_valid(handle))
 206                 jbd2_journal_release_buffer(handle, bh);
 207 }
 208
 209 static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
 210 {
 211         return ext4_journal_start_sb(inode->i_sb, nblocks);
 212 }
 213
 214 #define ext4_journal_stop(handle) \
 215         __ext4_journal_stop(__func__, (handle))
 216
 217 static inline handle_t *ext4_journal_current_handle(void)
 218 {
 219         return journal_current_handle();
 220 }
 221
 222 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 223 {
 224         if (ext4_handle_valid(handle))
 225                 return jbd2_journal_extend(handle, nblocks);
 226         return 0;
 227 }
 228
 229 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 230 {
 231         if (ext4_handle_valid(handle))
 232                 return jbd2_journal_restart(handle, nblocks);
 233         return 0;
 234 }
 235
 236 static inline int ext4_journal_blocks_per_page(struct inode *inode)
 237 {
 238         if (EXT4_JOURNAL(inode) != NULL)
 239                 return jbd2_journal_blocks_per_page(inode);
 240         return 0;
 241 }
 242
 243 static inline int ext4_journal_force_commit(journal_t *journal)
 244 {
 245         if (journal)
 246                 return jbd2_journal_force_commit(journal);
 247         return 0;
 248 }
 249
 250 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
 251 {
 252         if (ext4_handle_valid(handle))
 253                 return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
 254         return 0;
 255 }
 256
 257 /* super.c */
 258 int ext4_force_commit(struct super_block *sb);
 259
 260 static inline int ext4_should_journal_data(struct inode *inode)
 261 {
 262         if (EXT4_JOURNAL(inode) == NULL)
 263                 return 0;
 264         if (!S_ISREG(inode->i_mode))
 265                 return 1;
 266         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 267                 return 1;
 268         if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
 269                 return 1;
 270         return 0;
 271 }
 272
 273 static inline int ext4_should_order_data(struct inode *inode)
 274 {
 275         if (EXT4_JOURNAL(inode) == NULL)
 276                 return 0;
 277         if (!S_ISREG(inode->i_mode))
 278                 return 0;
 279         if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
 280                 return 0;
 281         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 282                 return 1;
 283         return 0;
 284 }
 285
 286 static inline int ext4_should_writeback_data(struct inode *inode)
 287 {
 288         if (!S_ISREG(inode->i_mode))
 289                 return 0;
 290         if (EXT4_JOURNAL(inode) == NULL)
 291                 return 1;
 292         if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
 293                 return 0;
 294         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 295                 return 1;
 296         return 0;
 297 }
 298
 299 #endif  /* _EXT4_JBD2_H */