diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/buffer_head.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/buffer_head.h')
-rw-r--r-- | include/linux/buffer_head.h | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h new file mode 100644 index 000000000000..802c91e9b3da --- /dev/null +++ b/include/linux/buffer_head.h | |||
@@ -0,0 +1,296 @@ | |||
1 | /* | ||
2 | * include/linux/buffer_head.h | ||
3 | * | ||
4 | * Everything to do with buffer_heads. | ||
5 | */ | ||
6 | |||
7 | #ifndef _LINUX_BUFFER_HEAD_H | ||
8 | #define _LINUX_BUFFER_HEAD_H | ||
9 | |||
10 | #include <linux/types.h> | ||
11 | #include <linux/fs.h> | ||
12 | #include <linux/linkage.h> | ||
13 | #include <linux/pagemap.h> | ||
14 | #include <linux/wait.h> | ||
15 | #include <asm/atomic.h> | ||
16 | |||
17 | enum bh_state_bits { | ||
18 | BH_Uptodate, /* Contains valid data */ | ||
19 | BH_Dirty, /* Is dirty */ | ||
20 | BH_Lock, /* Is locked */ | ||
21 | BH_Req, /* Has been submitted for I/O */ | ||
22 | |||
23 | BH_Mapped, /* Has a disk mapping */ | ||
24 | BH_New, /* Disk mapping was newly created by get_block */ | ||
25 | BH_Async_Read, /* Is under end_buffer_async_read I/O */ | ||
26 | BH_Async_Write, /* Is under end_buffer_async_write I/O */ | ||
27 | BH_Delay, /* Buffer is not yet allocated on disk */ | ||
28 | BH_Boundary, /* Block is followed by a discontiguity */ | ||
29 | BH_Write_EIO, /* I/O error on write */ | ||
30 | BH_Ordered, /* ordered write */ | ||
31 | BH_Eopnotsupp, /* operation not supported (barrier) */ | ||
32 | |||
33 | BH_PrivateStart,/* not a state bit, but the first bit available | ||
34 | * for private allocation by other entities | ||
35 | */ | ||
36 | }; | ||
37 | |||
38 | #define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512) | ||
39 | |||
40 | struct page; | ||
41 | struct buffer_head; | ||
42 | struct address_space; | ||
43 | typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate); | ||
44 | |||
45 | /* | ||
46 | * Keep related fields in common cachelines. The most commonly accessed | ||
47 | * field (b_state) goes at the start so the compiler does not generate | ||
48 | * indexed addressing for it. | ||
49 | */ | ||
50 | struct buffer_head { | ||
51 | /* First cache line: */ | ||
52 | unsigned long b_state; /* buffer state bitmap (see above) */ | ||
53 | struct buffer_head *b_this_page;/* circular list of page's buffers */ | ||
54 | struct page *b_page; /* the page this bh is mapped to */ | ||
55 | atomic_t b_count; /* users using this block */ | ||
56 | u32 b_size; /* block size */ | ||
57 | |||
58 | sector_t b_blocknr; /* block number */ | ||
59 | char *b_data; /* pointer to data block */ | ||
60 | |||
61 | struct block_device *b_bdev; | ||
62 | bh_end_io_t *b_end_io; /* I/O completion */ | ||
63 | void *b_private; /* reserved for b_end_io */ | ||
64 | struct list_head b_assoc_buffers; /* associated with another mapping */ | ||
65 | }; | ||
66 | |||
67 | /* | ||
68 | * macro tricks to expand the set_buffer_foo(), clear_buffer_foo() | ||
69 | * and buffer_foo() functions. | ||
70 | */ | ||
71 | #define BUFFER_FNS(bit, name) \ | ||
72 | static inline void set_buffer_##name(struct buffer_head *bh) \ | ||
73 | { \ | ||
74 | set_bit(BH_##bit, &(bh)->b_state); \ | ||
75 | } \ | ||
76 | static inline void clear_buffer_##name(struct buffer_head *bh) \ | ||
77 | { \ | ||
78 | clear_bit(BH_##bit, &(bh)->b_state); \ | ||
79 | } \ | ||
80 | static inline int buffer_##name(const struct buffer_head *bh) \ | ||
81 | { \ | ||
82 | return test_bit(BH_##bit, &(bh)->b_state); \ | ||
83 | } | ||
84 | |||
85 | /* | ||
86 | * test_set_buffer_foo() and test_clear_buffer_foo() | ||
87 | */ | ||
88 | #define TAS_BUFFER_FNS(bit, name) \ | ||
89 | static inline int test_set_buffer_##name(struct buffer_head *bh) \ | ||
90 | { \ | ||
91 | return test_and_set_bit(BH_##bit, &(bh)->b_state); \ | ||
92 | } \ | ||
93 | static inline int test_clear_buffer_##name(struct buffer_head *bh) \ | ||
94 | { \ | ||
95 | return test_and_clear_bit(BH_##bit, &(bh)->b_state); \ | ||
96 | } \ | ||
97 | |||
98 | /* | ||
99 | * Emit the buffer bitops functions. Note that there are also functions | ||
100 | * of the form "mark_buffer_foo()". These are higher-level functions which | ||
101 | * do something in addition to setting a b_state bit. | ||
102 | */ | ||
103 | BUFFER_FNS(Uptodate, uptodate) | ||
104 | BUFFER_FNS(Dirty, dirty) | ||
105 | TAS_BUFFER_FNS(Dirty, dirty) | ||
106 | BUFFER_FNS(Lock, locked) | ||
107 | TAS_BUFFER_FNS(Lock, locked) | ||
108 | BUFFER_FNS(Req, req) | ||
109 | TAS_BUFFER_FNS(Req, req) | ||
110 | BUFFER_FNS(Mapped, mapped) | ||
111 | BUFFER_FNS(New, new) | ||
112 | BUFFER_FNS(Async_Read, async_read) | ||
113 | BUFFER_FNS(Async_Write, async_write) | ||
114 | BUFFER_FNS(Delay, delay) | ||
115 | BUFFER_FNS(Boundary, boundary) | ||
116 | BUFFER_FNS(Write_EIO, write_io_error) | ||
117 | BUFFER_FNS(Ordered, ordered) | ||
118 | BUFFER_FNS(Eopnotsupp, eopnotsupp) | ||
119 | |||
120 | #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) | ||
121 | #define touch_buffer(bh) mark_page_accessed(bh->b_page) | ||
122 | |||
123 | /* If we *know* page->private refers to buffer_heads */ | ||
124 | #define page_buffers(page) \ | ||
125 | ({ \ | ||
126 | BUG_ON(!PagePrivate(page)); \ | ||
127 | ((struct buffer_head *)(page)->private); \ | ||
128 | }) | ||
129 | #define page_has_buffers(page) PagePrivate(page) | ||
130 | |||
131 | /* | ||
132 | * Declarations | ||
133 | */ | ||
134 | |||
135 | void FASTCALL(mark_buffer_dirty(struct buffer_head *bh)); | ||
136 | void init_buffer(struct buffer_head *, bh_end_io_t *, void *); | ||
137 | void set_bh_page(struct buffer_head *bh, | ||
138 | struct page *page, unsigned long offset); | ||
139 | int try_to_free_buffers(struct page *); | ||
140 | struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, | ||
141 | int retry); | ||
142 | void create_empty_buffers(struct page *, unsigned long, | ||
143 | unsigned long b_state); | ||
144 | void end_buffer_read_sync(struct buffer_head *bh, int uptodate); | ||
145 | void end_buffer_write_sync(struct buffer_head *bh, int uptodate); | ||
146 | void end_buffer_async_write(struct buffer_head *bh, int uptodate); | ||
147 | |||
148 | /* Things to do with buffers at mapping->private_list */ | ||
149 | void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode); | ||
150 | int inode_has_buffers(struct inode *); | ||
151 | void invalidate_inode_buffers(struct inode *); | ||
152 | int remove_inode_buffers(struct inode *inode); | ||
153 | int sync_mapping_buffers(struct address_space *mapping); | ||
154 | void unmap_underlying_metadata(struct block_device *bdev, sector_t block); | ||
155 | |||
156 | void mark_buffer_async_write(struct buffer_head *bh); | ||
157 | void invalidate_bdev(struct block_device *, int); | ||
158 | int sync_blockdev(struct block_device *bdev); | ||
159 | void __wait_on_buffer(struct buffer_head *); | ||
160 | wait_queue_head_t *bh_waitq_head(struct buffer_head *bh); | ||
161 | int fsync_bdev(struct block_device *); | ||
162 | struct super_block *freeze_bdev(struct block_device *); | ||
163 | void thaw_bdev(struct block_device *, struct super_block *); | ||
164 | int fsync_super(struct super_block *); | ||
165 | int fsync_no_super(struct block_device *); | ||
166 | struct buffer_head *__find_get_block(struct block_device *, sector_t, int); | ||
167 | struct buffer_head * __getblk(struct block_device *, sector_t, int); | ||
168 | void __brelse(struct buffer_head *); | ||
169 | void __bforget(struct buffer_head *); | ||
170 | void __breadahead(struct block_device *, sector_t block, int size); | ||
171 | struct buffer_head *__bread(struct block_device *, sector_t block, int size); | ||
172 | struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags); | ||
173 | void free_buffer_head(struct buffer_head * bh); | ||
174 | void FASTCALL(unlock_buffer(struct buffer_head *bh)); | ||
175 | void FASTCALL(__lock_buffer(struct buffer_head *bh)); | ||
176 | void ll_rw_block(int, int, struct buffer_head * bh[]); | ||
177 | int sync_dirty_buffer(struct buffer_head *bh); | ||
178 | int submit_bh(int, struct buffer_head *); | ||
179 | void write_boundary_block(struct block_device *bdev, | ||
180 | sector_t bblock, unsigned blocksize); | ||
181 | |||
182 | extern int buffer_heads_over_limit; | ||
183 | |||
184 | /* | ||
185 | * Generic address_space_operations implementations for buffer_head-backed | ||
186 | * address_spaces. | ||
187 | */ | ||
188 | int try_to_release_page(struct page * page, int gfp_mask); | ||
189 | int block_invalidatepage(struct page *page, unsigned long offset); | ||
190 | int block_write_full_page(struct page *page, get_block_t *get_block, | ||
191 | struct writeback_control *wbc); | ||
192 | int block_read_full_page(struct page*, get_block_t*); | ||
193 | int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*); | ||
194 | int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*, | ||
195 | loff_t *); | ||
196 | int generic_cont_expand(struct inode *inode, loff_t size) ; | ||
197 | int block_commit_write(struct page *page, unsigned from, unsigned to); | ||
198 | int block_sync_page(struct page *); | ||
199 | sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *); | ||
200 | int generic_commit_write(struct file *, struct page *, unsigned, unsigned); | ||
201 | int block_truncate_page(struct address_space *, loff_t, get_block_t *); | ||
202 | int file_fsync(struct file *, struct dentry *, int); | ||
203 | int nobh_prepare_write(struct page*, unsigned, unsigned, get_block_t*); | ||
204 | int nobh_commit_write(struct file *, struct page *, unsigned, unsigned); | ||
205 | int nobh_truncate_page(struct address_space *, loff_t); | ||
206 | int nobh_writepage(struct page *page, get_block_t *get_block, | ||
207 | struct writeback_control *wbc); | ||
208 | |||
209 | |||
210 | /* | ||
211 | * inline definitions | ||
212 | */ | ||
213 | |||
214 | static inline void attach_page_buffers(struct page *page, | ||
215 | struct buffer_head *head) | ||
216 | { | ||
217 | page_cache_get(page); | ||
218 | SetPagePrivate(page); | ||
219 | page->private = (unsigned long)head; | ||
220 | } | ||
221 | |||
222 | static inline void get_bh(struct buffer_head *bh) | ||
223 | { | ||
224 | atomic_inc(&bh->b_count); | ||
225 | } | ||
226 | |||
227 | static inline void put_bh(struct buffer_head *bh) | ||
228 | { | ||
229 | smp_mb__before_atomic_dec(); | ||
230 | atomic_dec(&bh->b_count); | ||
231 | } | ||
232 | |||
233 | static inline void brelse(struct buffer_head *bh) | ||
234 | { | ||
235 | if (bh) | ||
236 | __brelse(bh); | ||
237 | } | ||
238 | |||
239 | static inline void bforget(struct buffer_head *bh) | ||
240 | { | ||
241 | if (bh) | ||
242 | __bforget(bh); | ||
243 | } | ||
244 | |||
245 | static inline struct buffer_head * | ||
246 | sb_bread(struct super_block *sb, sector_t block) | ||
247 | { | ||
248 | return __bread(sb->s_bdev, block, sb->s_blocksize); | ||
249 | } | ||
250 | |||
251 | static inline void | ||
252 | sb_breadahead(struct super_block *sb, sector_t block) | ||
253 | { | ||
254 | __breadahead(sb->s_bdev, block, sb->s_blocksize); | ||
255 | } | ||
256 | |||
257 | static inline struct buffer_head * | ||
258 | sb_getblk(struct super_block *sb, sector_t block) | ||
259 | { | ||
260 | return __getblk(sb->s_bdev, block, sb->s_blocksize); | ||
261 | } | ||
262 | |||
263 | static inline struct buffer_head * | ||
264 | sb_find_get_block(struct super_block *sb, sector_t block) | ||
265 | { | ||
266 | return __find_get_block(sb->s_bdev, block, sb->s_blocksize); | ||
267 | } | ||
268 | |||
269 | static inline void | ||
270 | map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block) | ||
271 | { | ||
272 | set_buffer_mapped(bh); | ||
273 | bh->b_bdev = sb->s_bdev; | ||
274 | bh->b_blocknr = block; | ||
275 | } | ||
276 | |||
277 | /* | ||
278 | * Calling wait_on_buffer() for a zero-ref buffer is illegal, so we call into | ||
279 | * __wait_on_buffer() just to trip a debug check. Because debug code in inline | ||
280 | * functions is bloaty. | ||
281 | */ | ||
282 | static inline void wait_on_buffer(struct buffer_head *bh) | ||
283 | { | ||
284 | might_sleep(); | ||
285 | if (buffer_locked(bh) || atomic_read(&bh->b_count) == 0) | ||
286 | __wait_on_buffer(bh); | ||
287 | } | ||
288 | |||
289 | static inline void lock_buffer(struct buffer_head *bh) | ||
290 | { | ||
291 | might_sleep(); | ||
292 | if (test_set_buffer_locked(bh)) | ||
293 | __lock_buffer(bh); | ||
294 | } | ||
295 | |||
296 | #endif /* _LINUX_BUFFER_HEAD_H */ | ||