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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#ifdef CONFIG_BLOCK
18
19enum bh_state_bits {
20 BH_Uptodate,
21 BH_Dirty,
22 BH_Lock,
23 BH_Req,
24 BH_Uptodate_Lock,
25
26
27
28 BH_Mapped,
29 BH_New,
30 BH_Async_Read,
31 BH_Async_Write,
32 BH_Delay,
33 BH_Boundary,
34 BH_Write_EIO,
35 BH_Unwritten,
36 BH_Quiet,
37
38 BH_PrivateStart,
39
40
41};
42
43#define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
44
45struct page;
46struct buffer_head;
47struct address_space;
48typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
49
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57
58
59struct buffer_head {
60 unsigned long b_state;
61 struct buffer_head *b_this_page;
62 struct page *b_page;
63
64 sector_t b_blocknr;
65 size_t b_size;
66 char *b_data;
67
68 struct block_device *b_bdev;
69 bh_end_io_t *b_end_io;
70 void *b_private;
71 struct list_head b_assoc_buffers;
72 struct address_space *b_assoc_map;
73
74 atomic_t b_count;
75};
76
77
78
79
80
81#define BUFFER_FNS(bit, name) \
82static inline void set_buffer_##name(struct buffer_head *bh) \
83{ \
84 set_bit(BH_##bit, &(bh)->b_state); \
85} \
86static inline void clear_buffer_##name(struct buffer_head *bh) \
87{ \
88 clear_bit(BH_##bit, &(bh)->b_state); \
89} \
90static inline int buffer_##name(const struct buffer_head *bh) \
91{ \
92 return test_bit(BH_##bit, &(bh)->b_state); \
93}
94
95
96
97
98#define TAS_BUFFER_FNS(bit, name) \
99static inline int test_set_buffer_##name(struct buffer_head *bh) \
100{ \
101 return test_and_set_bit(BH_##bit, &(bh)->b_state); \
102} \
103static inline int test_clear_buffer_##name(struct buffer_head *bh) \
104{ \
105 return test_and_clear_bit(BH_##bit, &(bh)->b_state); \
106} \
107
108
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111
112
113BUFFER_FNS(Uptodate, uptodate)
114BUFFER_FNS(Dirty, dirty)
115TAS_BUFFER_FNS(Dirty, dirty)
116BUFFER_FNS(Lock, locked)
117BUFFER_FNS(Req, req)
118TAS_BUFFER_FNS(Req, req)
119BUFFER_FNS(Mapped, mapped)
120BUFFER_FNS(New, new)
121BUFFER_FNS(Async_Read, async_read)
122BUFFER_FNS(Async_Write, async_write)
123BUFFER_FNS(Delay, delay)
124BUFFER_FNS(Boundary, boundary)
125BUFFER_FNS(Write_EIO, write_io_error)
126BUFFER_FNS(Unwritten, unwritten)
127
128#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
129#define touch_buffer(bh) mark_page_accessed(bh->b_page)
130
131
132#define page_buffers(page) \
133 ({ \
134 BUG_ON(!PagePrivate(page)); \
135 ((struct buffer_head *)page_private(page)); \
136 })
137#define page_has_buffers(page) PagePrivate(page)
138
139
140
141
142
143void mark_buffer_dirty(struct buffer_head *bh);
144void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
145void set_bh_page(struct buffer_head *bh,
146 struct page *page, unsigned long offset);
147int try_to_free_buffers(struct page *);
148struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
149 int retry);
150void create_empty_buffers(struct page *, unsigned long,
151 unsigned long b_state);
152void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
153void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
154void end_buffer_async_write(struct buffer_head *bh, int uptodate);
155
156
157void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
158int inode_has_buffers(struct inode *);
159void invalidate_inode_buffers(struct inode *);
160int remove_inode_buffers(struct inode *inode);
161int sync_mapping_buffers(struct address_space *mapping);
162void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
163
164void mark_buffer_async_write(struct buffer_head *bh);
165void __wait_on_buffer(struct buffer_head *);
166wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
167struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
168 unsigned size);
169struct buffer_head *__getblk(struct block_device *bdev, sector_t block,
170 unsigned size);
171void __brelse(struct buffer_head *);
172void __bforget(struct buffer_head *);
173void __breadahead(struct block_device *, sector_t block, unsigned int size);
174struct buffer_head *__bread(struct block_device *, sector_t block, unsigned size);
175void invalidate_bh_lrus(void);
176struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
177void free_buffer_head(struct buffer_head * bh);
178void unlock_buffer(struct buffer_head *bh);
179void __lock_buffer(struct buffer_head *bh);
180void ll_rw_block(int, int, struct buffer_head * bh[]);
181int sync_dirty_buffer(struct buffer_head *bh);
182int __sync_dirty_buffer(struct buffer_head *bh, int rw);
183void write_dirty_buffer(struct buffer_head *bh, int rw);
184int submit_bh(int, struct buffer_head *);
185void write_boundary_block(struct block_device *bdev,
186 sector_t bblock, unsigned blocksize);
187int bh_uptodate_or_lock(struct buffer_head *bh);
188int bh_submit_read(struct buffer_head *bh);
189
190extern int buffer_heads_over_limit;
191
192
193
194
195
196void block_invalidatepage(struct page *page, unsigned long offset);
197int block_write_full_page(struct page *page, get_block_t *get_block,
198 struct writeback_control *wbc);
199int block_write_full_page_endio(struct page *page, get_block_t *get_block,
200 struct writeback_control *wbc, bh_end_io_t *handler);
201int block_read_full_page(struct page*, get_block_t*);
202int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
203 unsigned long from);
204int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
205 unsigned flags, struct page **pagep, get_block_t *get_block);
206int __block_write_begin(struct page *page, loff_t pos, unsigned len,
207 get_block_t *get_block);
208int block_write_end(struct file *, struct address_space *,
209 loff_t, unsigned, unsigned,
210 struct page *, void *);
211int generic_write_end(struct file *, struct address_space *,
212 loff_t, unsigned, unsigned,
213 struct page *, void *);
214void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
215int cont_write_begin(struct file *, struct address_space *, loff_t,
216 unsigned, unsigned, struct page **, void **,
217 get_block_t *, loff_t *);
218int generic_cont_expand_simple(struct inode *inode, loff_t size);
219int block_commit_write(struct page *page, unsigned from, unsigned to);
220int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
221 get_block_t get_block);
222void block_sync_page(struct page *);
223sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
224int block_truncate_page(struct address_space *, loff_t, get_block_t *);
225int nobh_write_begin(struct address_space *, loff_t, unsigned, unsigned,
226 struct page **, void **, get_block_t*);
227int nobh_write_end(struct file *, struct address_space *,
228 loff_t, unsigned, unsigned,
229 struct page *, void *);
230int nobh_truncate_page(struct address_space *, loff_t, get_block_t *);
231int nobh_writepage(struct page *page, get_block_t *get_block,
232 struct writeback_control *wbc);
233
234void buffer_init(void);
235
236
237
238
239
240static inline void attach_page_buffers(struct page *page,
241 struct buffer_head *head)
242{
243 page_cache_get(page);
244 SetPagePrivate(page);
245 set_page_private(page, (unsigned long)head);
246}
247
248static inline void get_bh(struct buffer_head *bh)
249{
250 atomic_inc(&bh->b_count);
251}
252
253static inline void put_bh(struct buffer_head *bh)
254{
255 smp_mb__before_atomic_dec();
256 atomic_dec(&bh->b_count);
257}
258
259static inline void brelse(struct buffer_head *bh)
260{
261 if (bh)
262 __brelse(bh);
263}
264
265static inline void bforget(struct buffer_head *bh)
266{
267 if (bh)
268 __bforget(bh);
269}
270
271static inline struct buffer_head *
272sb_bread(struct super_block *sb, sector_t block)
273{
274 return __bread(sb->s_bdev, block, sb->s_blocksize);
275}
276
277static inline void
278sb_breadahead(struct super_block *sb, sector_t block)
279{
280 __breadahead(sb->s_bdev, block, sb->s_blocksize);
281}
282
283static inline struct buffer_head *
284sb_getblk(struct super_block *sb, sector_t block)
285{
286 return __getblk(sb->s_bdev, block, sb->s_blocksize);
287}
288
289static inline struct buffer_head *
290sb_find_get_block(struct super_block *sb, sector_t block)
291{
292 return __find_get_block(sb->s_bdev, block, sb->s_blocksize);
293}
294
295static inline void
296map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
297{
298 set_buffer_mapped(bh);
299 bh->b_bdev = sb->s_bdev;
300 bh->b_blocknr = block;
301 bh->b_size = sb->s_blocksize;
302}
303
304static inline void wait_on_buffer(struct buffer_head *bh)
305{
306 might_sleep();
307 if (buffer_locked(bh))
308 __wait_on_buffer(bh);
309}
310
311static inline int trylock_buffer(struct buffer_head *bh)
312{
313 return likely(!test_and_set_bit_lock(BH_Lock, &bh->b_state));
314}
315
316static inline void lock_buffer(struct buffer_head *bh)
317{
318 might_sleep();
319 if (!trylock_buffer(bh))
320 __lock_buffer(bh);
321}
322
323extern int __set_page_dirty_buffers(struct page *page);
324
325#else
326
327static inline void buffer_init(void) {}
328static inline int try_to_free_buffers(struct page *page) { return 1; }
329static inline int inode_has_buffers(struct inode *inode) { return 0; }
330static inline void invalidate_inode_buffers(struct inode *inode) {}
331static inline int remove_inode_buffers(struct inode *inode) { return 1; }
332static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
333
334#endif
335#endif
336