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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 <linux/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 BH_Meta,
38 BH_Prio,
39
40 BH_PrivateStart,
41
42
43};
44
45#define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
46
47struct page;
48struct buffer_head;
49struct address_space;
50typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
51
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59
60
61struct buffer_head {
62 unsigned long b_state;
63 struct buffer_head *b_this_page;
64 struct page *b_page;
65
66 sector_t b_blocknr;
67 size_t b_size;
68 char *b_data;
69
70 struct block_device *b_bdev;
71 bh_end_io_t *b_end_io;
72 void *b_private;
73 struct list_head b_assoc_buffers;
74 struct address_space *b_assoc_map;
75
76 atomic_t b_count;
77};
78
79
80
81
82
83#define BUFFER_FNS(bit, name) \
84static inline void set_buffer_##name(struct buffer_head *bh) \
85{ \
86 set_bit(BH_##bit, &(bh)->b_state); \
87} \
88static inline void clear_buffer_##name(struct buffer_head *bh) \
89{ \
90 clear_bit(BH_##bit, &(bh)->b_state); \
91} \
92static inline int buffer_##name(const struct buffer_head *bh) \
93{ \
94 return test_bit(BH_##bit, &(bh)->b_state); \
95}
96
97
98
99
100#define TAS_BUFFER_FNS(bit, name) \
101static inline int test_set_buffer_##name(struct buffer_head *bh) \
102{ \
103 return test_and_set_bit(BH_##bit, &(bh)->b_state); \
104} \
105static inline int test_clear_buffer_##name(struct buffer_head *bh) \
106{ \
107 return test_and_clear_bit(BH_##bit, &(bh)->b_state); \
108} \
109
110
111
112
113
114
115BUFFER_FNS(Uptodate, uptodate)
116BUFFER_FNS(Dirty, dirty)
117TAS_BUFFER_FNS(Dirty, dirty)
118BUFFER_FNS(Lock, locked)
119BUFFER_FNS(Req, req)
120TAS_BUFFER_FNS(Req, req)
121BUFFER_FNS(Mapped, mapped)
122BUFFER_FNS(New, new)
123BUFFER_FNS(Async_Read, async_read)
124BUFFER_FNS(Async_Write, async_write)
125BUFFER_FNS(Delay, delay)
126BUFFER_FNS(Boundary, boundary)
127BUFFER_FNS(Write_EIO, write_io_error)
128BUFFER_FNS(Unwritten, unwritten)
129BUFFER_FNS(Meta, meta)
130BUFFER_FNS(Prio, prio)
131
132#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
133
134
135#define page_buffers(page) \
136 ({ \
137 BUG_ON(!PagePrivate(page)); \
138 ((struct buffer_head *)page_private(page)); \
139 })
140#define page_has_buffers(page) PagePrivate(page)
141
142void buffer_check_dirty_writeback(struct page *page,
143 bool *dirty, bool *writeback);
144
145
146
147
148
149void mark_buffer_dirty(struct buffer_head *bh);
150void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
151void touch_buffer(struct buffer_head *bh);
152void set_bh_page(struct buffer_head *bh,
153 struct page *page, unsigned long offset);
154int try_to_free_buffers(struct page *);
155struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
156 int retry);
157void create_empty_buffers(struct page *, unsigned long,
158 unsigned long b_state);
159void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
160void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
161void end_buffer_async_write(struct buffer_head *bh, int uptodate);
162
163
164void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
165int inode_has_buffers(struct inode *);
166void invalidate_inode_buffers(struct inode *);
167int remove_inode_buffers(struct inode *inode);
168int sync_mapping_buffers(struct address_space *mapping);
169void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
170
171void mark_buffer_async_write(struct buffer_head *bh);
172void __wait_on_buffer(struct buffer_head *);
173wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
174struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
175 unsigned size);
176struct buffer_head *__getblk(struct block_device *bdev, sector_t block,
177 unsigned size);
178void __brelse(struct buffer_head *);
179void __bforget(struct buffer_head *);
180void __breadahead(struct block_device *, sector_t block, unsigned int size);
181struct buffer_head *__bread(struct block_device *, sector_t block, unsigned size);
182void invalidate_bh_lrus(void);
183struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
184void free_buffer_head(struct buffer_head * bh);
185void unlock_buffer(struct buffer_head *bh);
186void __lock_buffer(struct buffer_head *bh);
187void ll_rw_block(int, int, struct buffer_head * bh[]);
188int sync_dirty_buffer(struct buffer_head *bh);
189int __sync_dirty_buffer(struct buffer_head *bh, int rw);
190void write_dirty_buffer(struct buffer_head *bh, int rw);
191int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags);
192int submit_bh(int, struct buffer_head *);
193void write_boundary_block(struct block_device *bdev,
194 sector_t bblock, unsigned blocksize);
195int bh_uptodate_or_lock(struct buffer_head *bh);
196int bh_submit_read(struct buffer_head *bh);
197
198extern int buffer_heads_over_limit;
199
200
201
202
203
204void block_invalidatepage(struct page *page, unsigned int offset,
205 unsigned int length);
206int block_write_full_page(struct page *page, get_block_t *get_block,
207 struct writeback_control *wbc);
208int block_write_full_page_endio(struct page *page, get_block_t *get_block,
209 struct writeback_control *wbc, bh_end_io_t *handler);
210int block_read_full_page(struct page*, get_block_t*);
211int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
212 unsigned long from);
213int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
214 unsigned flags, struct page **pagep, get_block_t *get_block);
215int __block_write_begin(struct page *page, loff_t pos, unsigned len,
216 get_block_t *get_block);
217int block_write_end(struct file *, struct address_space *,
218 loff_t, unsigned, unsigned,
219 struct page *, void *);
220int generic_write_end(struct file *, struct address_space *,
221 loff_t, unsigned, unsigned,
222 struct page *, void *);
223void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
224int cont_write_begin(struct file *, struct address_space *, loff_t,
225 unsigned, unsigned, struct page **, void **,
226 get_block_t *, loff_t *);
227int generic_cont_expand_simple(struct inode *inode, loff_t size);
228int block_commit_write(struct page *page, unsigned from, unsigned to);
229int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
230 get_block_t get_block);
231int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
232 get_block_t get_block);
233
234static inline int block_page_mkwrite_return(int err)
235{
236 if (err == 0)
237 return VM_FAULT_LOCKED;
238 if (err == -EFAULT)
239 return VM_FAULT_NOPAGE;
240 if (err == -ENOMEM)
241 return VM_FAULT_OOM;
242 if (err == -EAGAIN)
243 return VM_FAULT_RETRY;
244
245 return VM_FAULT_SIGBUS;
246}
247sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
248int block_truncate_page(struct address_space *, loff_t, get_block_t *);
249int nobh_write_begin(struct address_space *, loff_t, unsigned, unsigned,
250 struct page **, void **, get_block_t*);
251int nobh_write_end(struct file *, struct address_space *,
252 loff_t, unsigned, unsigned,
253 struct page *, void *);
254int nobh_truncate_page(struct address_space *, loff_t, get_block_t *);
255int nobh_writepage(struct page *page, get_block_t *get_block,
256 struct writeback_control *wbc);
257
258void buffer_init(void);
259
260
261
262
263
264static inline void attach_page_buffers(struct page *page,
265 struct buffer_head *head)
266{
267 page_cache_get(page);
268 SetPagePrivate(page);
269 set_page_private(page, (unsigned long)head);
270}
271
272static inline void get_bh(struct buffer_head *bh)
273{
274 atomic_inc(&bh->b_count);
275}
276
277static inline void put_bh(struct buffer_head *bh)
278{
279 smp_mb__before_atomic_dec();
280 atomic_dec(&bh->b_count);
281}
282
283static inline void brelse(struct buffer_head *bh)
284{
285 if (bh)
286 __brelse(bh);
287}
288
289static inline void bforget(struct buffer_head *bh)
290{
291 if (bh)
292 __bforget(bh);
293}
294
295static inline struct buffer_head *
296sb_bread(struct super_block *sb, sector_t block)
297{
298 return __bread(sb->s_bdev, block, sb->s_blocksize);
299}
300
301static inline void
302sb_breadahead(struct super_block *sb, sector_t block)
303{
304 __breadahead(sb->s_bdev, block, sb->s_blocksize);
305}
306
307static inline struct buffer_head *
308sb_getblk(struct super_block *sb, sector_t block)
309{
310 return __getblk(sb->s_bdev, block, sb->s_blocksize);
311}
312
313static inline struct buffer_head *
314sb_find_get_block(struct super_block *sb, sector_t block)
315{
316 return __find_get_block(sb->s_bdev, block, sb->s_blocksize);
317}
318
319static inline void
320map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
321{
322 set_buffer_mapped(bh);
323 bh->b_bdev = sb->s_bdev;
324 bh->b_blocknr = block;
325 bh->b_size = sb->s_blocksize;
326}
327
328static inline void wait_on_buffer(struct buffer_head *bh)
329{
330 might_sleep();
331 if (buffer_locked(bh))
332 __wait_on_buffer(bh);
333}
334
335static inline int trylock_buffer(struct buffer_head *bh)
336{
337 return likely(!test_and_set_bit_lock(BH_Lock, &bh->b_state));
338}
339
340static inline void lock_buffer(struct buffer_head *bh)
341{
342 might_sleep();
343 if (!trylock_buffer(bh))
344 __lock_buffer(bh);
345}
346
347extern int __set_page_dirty_buffers(struct page *page);
348
349#else
350
351static inline void buffer_init(void) {}
352static inline int try_to_free_buffers(struct page *page) { return 1; }
353static inline int inode_has_buffers(struct inode *inode) { return 0; }
354static inline void invalidate_inode_buffers(struct inode *inode) {}
355static inline int remove_inode_buffers(struct inode *inode) { return 1; }
356static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
357
358#endif
359#endif
360