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ext4_jbd2.h
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1 /*
2  * ext4_jbd2.h
3  *
4  * Written by Stephen C. Tweedie <[email protected]>, 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 
122  /* list information for other callbacks attached to the same handle */
124 
125  /* Function to call with this callback structure */
127  struct ext4_journal_cb_entry *jce, int error);
128 
129  /* user data goes here */
130 };
131 
153 static 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 
174 static 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 
185 int
186 ext4_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 
195 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
196  struct ext4_iloc *iloc);
197 
198 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
199 
200 /*
201  * Wrapper functions with which ext4 calls into JBD.
202  */
203 void 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 
207 int __ext4_journal_get_write_access(const char *where, unsigned int line,
208  handle_t *handle, struct buffer_head *bh);
209 
210 int __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 
214 int __ext4_journal_get_create_access(const char *where, unsigned int line,
215  handle_t *handle, struct buffer_head *bh);
216 
217 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
218  handle_t *handle, struct inode *inode,
219  struct buffer_head *bh);
220 
221 int __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 
237 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
238 int __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. */
244 static 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 
251 static inline void ext4_handle_sync(handle_t *handle)
252 {
253  if (ext4_handle_valid(handle))
254  handle->h_sync = 1;
255 }
256 
257 static 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 
264 static 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 
271 static 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 
278 static 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 
286 static inline handle_t *ext4_journal_current_handle(void)
287 {
288  return journal_current_handle();
289 }
290 
291 static 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 
298 static 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 
305 static 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 
312 static 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 
319 static 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 
326 static 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 */
340 int 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 
349 static 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 
368 static inline int ext4_should_journal_data(struct inode *inode)
369 {
370  return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
371 }
372 
373 static inline int ext4_should_order_data(struct inode *inode)
374 {
375  return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
376 }
377 
378 static 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  */
392 static 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 */