Root/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
103int
104ext4_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
113int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
114            struct ext4_iloc *iloc);
115
116int 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
125void ext4_journal_abort_handle(const char *caller, const char *err_fn,
126        struct buffer_head *bh, handle_t *handle, int err);
127
128int __ext4_journal_get_undo_access(const char *where, handle_t *handle,
129                struct buffer_head *bh);
130
131int __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 */
135int __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 */
139int __ext4_journal_revoke(const char *where, handle_t *handle,
140                ext4_fsblk_t blocknr, struct buffer_head *bh);
141
142int __ext4_journal_get_create_access(const char *where,
143                handle_t *handle, struct buffer_head *bh);
144
145int __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
161handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
162int __ext4_journal_stop(const char *where, handle_t *handle);
163
164#define EXT4_NOJOURNAL_HANDLE ((handle_t *) 0x1)
165
166static inline int ext4_handle_valid(handle_t *handle)
167{
168    if (handle == EXT4_NOJOURNAL_HANDLE)
169        return 0;
170    return 1;
171}
172
173static inline void ext4_handle_sync(handle_t *handle)
174{
175    if (ext4_handle_valid(handle))
176        handle->h_sync = 1;
177}
178
179static inline void ext4_handle_release_buffer(handle_t *handle,
180                        struct buffer_head *bh)
181{
182    if (ext4_handle_valid(handle))
183        jbd2_journal_release_buffer(handle, bh);
184}
185
186static inline int ext4_handle_is_aborted(handle_t *handle)
187{
188    if (ext4_handle_valid(handle))
189        return is_handle_aborted(handle);
190    return 0;
191}
192
193static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
194{
195    if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
196        return 0;
197    return 1;
198}
199
200static inline void ext4_journal_release_buffer(handle_t *handle,
201                        struct buffer_head *bh)
202{
203    if (ext4_handle_valid(handle))
204        jbd2_journal_release_buffer(handle, bh);
205}
206
207static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
208{
209    return ext4_journal_start_sb(inode->i_sb, nblocks);
210}
211
212#define ext4_journal_stop(handle) \
213    __ext4_journal_stop(__func__, (handle))
214
215static inline handle_t *ext4_journal_current_handle(void)
216{
217    return journal_current_handle();
218}
219
220static inline int ext4_journal_extend(handle_t *handle, int nblocks)
221{
222    if (ext4_handle_valid(handle))
223        return jbd2_journal_extend(handle, nblocks);
224    return 0;
225}
226
227static inline int ext4_journal_restart(handle_t *handle, int nblocks)
228{
229    if (ext4_handle_valid(handle))
230        return jbd2_journal_restart(handle, nblocks);
231    return 0;
232}
233
234static inline int ext4_journal_blocks_per_page(struct inode *inode)
235{
236    if (EXT4_JOURNAL(inode) != NULL)
237        return jbd2_journal_blocks_per_page(inode);
238    return 0;
239}
240
241static inline int ext4_journal_force_commit(journal_t *journal)
242{
243    if (journal)
244        return jbd2_journal_force_commit(journal);
245    return 0;
246}
247
248static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
249{
250    if (ext4_handle_valid(handle))
251        return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
252    return 0;
253}
254
255/* super.c */
256int ext4_force_commit(struct super_block *sb);
257
258static inline int ext4_should_journal_data(struct inode *inode)
259{
260    if (EXT4_JOURNAL(inode) == NULL)
261        return 0;
262    if (!S_ISREG(inode->i_mode))
263        return 1;
264    if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
265        return 1;
266    if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
267        return 1;
268    return 0;
269}
270
271static inline int ext4_should_order_data(struct inode *inode)
272{
273    if (EXT4_JOURNAL(inode) == NULL)
274        return 0;
275    if (!S_ISREG(inode->i_mode))
276        return 0;
277    if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
278        return 0;
279    if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
280        return 1;
281    return 0;
282}
283
284static inline int ext4_should_writeback_data(struct inode *inode)
285{
286    if (!S_ISREG(inode->i_mode))
287        return 0;
288    if (EXT4_JOURNAL(inode) == NULL)
289        return 1;
290    if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
291        return 0;
292    if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
293        return 1;
294    return 0;
295}
296
297#endif /* _EXT4_JBD2_H */
298

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