Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * include/linux/buffer_head.h | |
4 | * | |
5 | * Everything to do with buffer_heads. | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_BUFFER_HEAD_H | |
9 | #define _LINUX_BUFFER_HEAD_H | |
10 | ||
11 | #include <linux/types.h> | |
3ae72869 | 12 | #include <linux/blk_types.h> |
1da177e4 LT |
13 | #include <linux/fs.h> |
14 | #include <linux/linkage.h> | |
15 | #include <linux/pagemap.h> | |
16 | #include <linux/wait.h> | |
60063497 | 17 | #include <linux/atomic.h> |
1da177e4 | 18 | |
9361401e DH |
19 | #ifdef CONFIG_BLOCK |
20 | ||
1da177e4 LT |
21 | enum bh_state_bits { |
22 | BH_Uptodate, /* Contains valid data */ | |
23 | BH_Dirty, /* Is dirty */ | |
24 | BH_Lock, /* Is locked */ | |
25 | BH_Req, /* Has been submitted for I/O */ | |
26 | ||
27 | BH_Mapped, /* Has a disk mapping */ | |
28 | BH_New, /* Disk mapping was newly created by get_block */ | |
29 | BH_Async_Read, /* Is under end_buffer_async_read I/O */ | |
30 | BH_Async_Write, /* Is under end_buffer_async_write I/O */ | |
31 | BH_Delay, /* Buffer is not yet allocated on disk */ | |
32 | BH_Boundary, /* Block is followed by a discontiguity */ | |
33 | BH_Write_EIO, /* I/O error on write */ | |
33a266dd | 34 | BH_Unwritten, /* Buffer is allocated on disk but not written */ |
08bafc03 | 35 | BH_Quiet, /* Buffer Error Prinks to be quiet */ |
877f962c TT |
36 | BH_Meta, /* Buffer contains metadata */ |
37 | BH_Prio, /* Buffer should be submitted with REQ_PRIO */ | |
7b7a8665 | 38 | BH_Defer_Completion, /* Defer AIO completion to workqueue */ |
1da177e4 LT |
39 | |
40 | BH_PrivateStart,/* not a state bit, but the first bit available | |
41 | * for private allocation by other entities | |
42 | */ | |
43 | }; | |
44 | ||
09cbfeaf | 45 | #define MAX_BUF_PER_PAGE (PAGE_SIZE / 512) |
1da177e4 LT |
46 | |
47 | struct page; | |
48 | struct buffer_head; | |
49 | struct address_space; | |
50 | typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate); | |
51 | ||
52 | /* | |
205f87f6 BP |
53 | * Historically, a buffer_head was used to map a single block |
54 | * within a page, and of course as the unit of I/O through the | |
55 | * filesystem and block layers. Nowadays the basic I/O unit | |
56 | * is the bio, and buffer_heads are used for extracting block | |
57 | * mappings (via a get_block_t call), for tracking state within | |
58 | * a page (via a page_mapping) and for wrapping bio submission | |
59 | * for backward compatibility reasons (e.g. submit_bh). | |
1da177e4 LT |
60 | */ |
61 | struct buffer_head { | |
1da177e4 LT |
62 | unsigned long b_state; /* buffer state bitmap (see above) */ |
63 | struct buffer_head *b_this_page;/* circular list of page's buffers */ | |
d685c668 MWO |
64 | union { |
65 | struct page *b_page; /* the page this bh is mapped to */ | |
66 | struct folio *b_folio; /* the folio this bh is mapped to */ | |
67 | }; | |
1da177e4 | 68 | |
205f87f6 BP |
69 | sector_t b_blocknr; /* start block number */ |
70 | size_t b_size; /* size of mapping */ | |
71 | char *b_data; /* pointer to data within the page */ | |
1da177e4 LT |
72 | |
73 | struct block_device *b_bdev; | |
74 | bh_end_io_t *b_end_io; /* I/O completion */ | |
75 | void *b_private; /* reserved for b_end_io */ | |
76 | struct list_head b_assoc_buffers; /* associated with another mapping */ | |
58ff407b JK |
77 | struct address_space *b_assoc_map; /* mapping this buffer is |
78 | associated with */ | |
205f87f6 | 79 | atomic_t b_count; /* users using this buffer_head */ |
f1e67e35 TG |
80 | spinlock_t b_uptodate_lock; /* Used by the first bh in a page, to |
81 | * serialise IO completion of other | |
82 | * buffers in the page */ | |
1da177e4 LT |
83 | }; |
84 | ||
85 | /* | |
86 | * macro tricks to expand the set_buffer_foo(), clear_buffer_foo() | |
87 | * and buffer_foo() functions. | |
60f91826 KW |
88 | * To avoid reset buffer flags that are already set, because that causes |
89 | * a costly cache line transition, check the flag first. | |
1da177e4 LT |
90 | */ |
91 | #define BUFFER_FNS(bit, name) \ | |
ee91ef61 | 92 | static __always_inline void set_buffer_##name(struct buffer_head *bh) \ |
1da177e4 | 93 | { \ |
60f91826 KW |
94 | if (!test_bit(BH_##bit, &(bh)->b_state)) \ |
95 | set_bit(BH_##bit, &(bh)->b_state); \ | |
1da177e4 | 96 | } \ |
ee91ef61 | 97 | static __always_inline void clear_buffer_##name(struct buffer_head *bh) \ |
1da177e4 LT |
98 | { \ |
99 | clear_bit(BH_##bit, &(bh)->b_state); \ | |
100 | } \ | |
ee91ef61 | 101 | static __always_inline int buffer_##name(const struct buffer_head *bh) \ |
1da177e4 LT |
102 | { \ |
103 | return test_bit(BH_##bit, &(bh)->b_state); \ | |
104 | } | |
105 | ||
106 | /* | |
107 | * test_set_buffer_foo() and test_clear_buffer_foo() | |
108 | */ | |
109 | #define TAS_BUFFER_FNS(bit, name) \ | |
ee91ef61 | 110 | static __always_inline int test_set_buffer_##name(struct buffer_head *bh) \ |
1da177e4 LT |
111 | { \ |
112 | return test_and_set_bit(BH_##bit, &(bh)->b_state); \ | |
113 | } \ | |
ee91ef61 | 114 | static __always_inline int test_clear_buffer_##name(struct buffer_head *bh) \ |
1da177e4 LT |
115 | { \ |
116 | return test_and_clear_bit(BH_##bit, &(bh)->b_state); \ | |
117 | } \ | |
118 | ||
119 | /* | |
120 | * Emit the buffer bitops functions. Note that there are also functions | |
121 | * of the form "mark_buffer_foo()". These are higher-level functions which | |
122 | * do something in addition to setting a b_state bit. | |
123 | */ | |
1da177e4 LT |
124 | BUFFER_FNS(Dirty, dirty) |
125 | TAS_BUFFER_FNS(Dirty, dirty) | |
126 | BUFFER_FNS(Lock, locked) | |
1da177e4 LT |
127 | BUFFER_FNS(Req, req) |
128 | TAS_BUFFER_FNS(Req, req) | |
129 | BUFFER_FNS(Mapped, mapped) | |
130 | BUFFER_FNS(New, new) | |
131 | BUFFER_FNS(Async_Read, async_read) | |
132 | BUFFER_FNS(Async_Write, async_write) | |
133 | BUFFER_FNS(Delay, delay) | |
134 | BUFFER_FNS(Boundary, boundary) | |
135 | BUFFER_FNS(Write_EIO, write_io_error) | |
33a266dd | 136 | BUFFER_FNS(Unwritten, unwritten) |
877f962c TT |
137 | BUFFER_FNS(Meta, meta) |
138 | BUFFER_FNS(Prio, prio) | |
7b7a8665 | 139 | BUFFER_FNS(Defer_Completion, defer_completion) |
1da177e4 | 140 | |
d4252071 MP |
141 | static __always_inline void set_buffer_uptodate(struct buffer_head *bh) |
142 | { | |
2f79cdfe LT |
143 | /* |
144 | * If somebody else already set this uptodate, they will | |
145 | * have done the memory barrier, and a reader will thus | |
146 | * see *some* valid buffer state. | |
147 | * | |
148 | * Any other serialization (with IO errors or whatever that | |
149 | * might clear the bit) has to come from other state (eg BH_Lock). | |
150 | */ | |
151 | if (test_bit(BH_Uptodate, &bh->b_state)) | |
152 | return; | |
153 | ||
d4252071 MP |
154 | /* |
155 | * make it consistent with folio_mark_uptodate | |
156 | * pairs with smp_load_acquire in buffer_uptodate | |
157 | */ | |
158 | smp_mb__before_atomic(); | |
159 | set_bit(BH_Uptodate, &bh->b_state); | |
160 | } | |
161 | ||
162 | static __always_inline void clear_buffer_uptodate(struct buffer_head *bh) | |
163 | { | |
164 | clear_bit(BH_Uptodate, &bh->b_state); | |
165 | } | |
166 | ||
167 | static __always_inline int buffer_uptodate(const struct buffer_head *bh) | |
168 | { | |
169 | /* | |
170 | * make it consistent with folio_test_uptodate | |
171 | * pairs with smp_mb__before_atomic in set_buffer_uptodate | |
172 | */ | |
8238b457 | 173 | return test_bit_acquire(BH_Uptodate, &bh->b_state); |
d4252071 MP |
174 | } |
175 | ||
1da177e4 | 176 | #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) |
1da177e4 LT |
177 | |
178 | /* If we *know* page->private refers to buffer_heads */ | |
179 | #define page_buffers(page) \ | |
180 | ({ \ | |
4c21e2f2 HD |
181 | BUG_ON(!PagePrivate(page)); \ |
182 | ((struct buffer_head *)page_private(page)); \ | |
1da177e4 LT |
183 | }) |
184 | #define page_has_buffers(page) PagePrivate(page) | |
cd1067be | 185 | #define folio_buffers(folio) folio_get_private(folio) |
1da177e4 | 186 | |
520f301c | 187 | void buffer_check_dirty_writeback(struct folio *folio, |
b4597226 MG |
188 | bool *dirty, bool *writeback); |
189 | ||
1da177e4 LT |
190 | /* |
191 | * Declarations | |
192 | */ | |
193 | ||
b3c97528 | 194 | void mark_buffer_dirty(struct buffer_head *bh); |
87354e5d | 195 | void mark_buffer_write_io_error(struct buffer_head *bh); |
f0059afd | 196 | void touch_buffer(struct buffer_head *bh); |
1da177e4 LT |
197 | void set_bh_page(struct buffer_head *bh, |
198 | struct page *page, unsigned long offset); | |
465e5e6a PR |
199 | void folio_set_bh(struct buffer_head *bh, struct folio *folio, |
200 | unsigned long offset); | |
68189fef | 201 | bool try_to_free_buffers(struct folio *); |
c71124a8 PR |
202 | struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size, |
203 | bool retry); | |
1da177e4 | 204 | struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, |
640ab98f | 205 | bool retry); |
1da177e4 LT |
206 | void create_empty_buffers(struct page *, unsigned long, |
207 | unsigned long b_state); | |
8e2e1756 PR |
208 | void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize, |
209 | unsigned long b_state); | |
1da177e4 LT |
210 | void end_buffer_read_sync(struct buffer_head *bh, int uptodate); |
211 | void end_buffer_write_sync(struct buffer_head *bh, int uptodate); | |
35c80d5f | 212 | void end_buffer_async_write(struct buffer_head *bh, int uptodate); |
1da177e4 LT |
213 | |
214 | /* Things to do with buffers at mapping->private_list */ | |
215 | void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode); | |
216 | int inode_has_buffers(struct inode *); | |
217 | void invalidate_inode_buffers(struct inode *); | |
218 | int remove_inode_buffers(struct inode *inode); | |
219 | int sync_mapping_buffers(struct address_space *mapping); | |
31b2ebc0 RHI |
220 | int generic_buffers_fsync_noflush(struct file *file, loff_t start, loff_t end, |
221 | bool datasync); | |
222 | int generic_buffers_fsync(struct file *file, loff_t start, loff_t end, | |
223 | bool datasync); | |
29f3ad7d JK |
224 | void clean_bdev_aliases(struct block_device *bdev, sector_t block, |
225 | sector_t len); | |
e64855c6 JK |
226 | static inline void clean_bdev_bh_alias(struct buffer_head *bh) |
227 | { | |
228 | clean_bdev_aliases(bh->b_bdev, bh->b_blocknr, 1); | |
229 | } | |
1da177e4 LT |
230 | |
231 | void mark_buffer_async_write(struct buffer_head *bh); | |
1da177e4 LT |
232 | void __wait_on_buffer(struct buffer_head *); |
233 | wait_queue_head_t *bh_waitq_head(struct buffer_head *bh); | |
3991d3bd TK |
234 | struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block, |
235 | unsigned size); | |
3b5e6454 GK |
236 | struct buffer_head *__getblk_gfp(struct block_device *bdev, sector_t block, |
237 | unsigned size, gfp_t gfp); | |
1da177e4 LT |
238 | void __brelse(struct buffer_head *); |
239 | void __bforget(struct buffer_head *); | |
3991d3bd | 240 | void __breadahead(struct block_device *, sector_t block, unsigned int size); |
3b5e6454 GK |
241 | struct buffer_head *__bread_gfp(struct block_device *, |
242 | sector_t block, unsigned size, gfp_t gfp); | |
f9a14399 | 243 | void invalidate_bh_lrus(void); |
243418e3 | 244 | void invalidate_bh_lrus_cpu(void); |
8cc621d2 | 245 | bool has_bh_in_lru(int cpu, void *dummy); |
dd0fc66f | 246 | struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); |
1da177e4 | 247 | void free_buffer_head(struct buffer_head * bh); |
b3c97528 HH |
248 | void unlock_buffer(struct buffer_head *bh); |
249 | void __lock_buffer(struct buffer_head *bh); | |
1da177e4 | 250 | int sync_dirty_buffer(struct buffer_head *bh); |
3ae72869 BVA |
251 | int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags); |
252 | void write_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags); | |
5bdf402a | 253 | void submit_bh(blk_opf_t, struct buffer_head *); |
1da177e4 LT |
254 | void write_boundary_block(struct block_device *bdev, |
255 | sector_t bblock, unsigned blocksize); | |
389d1b08 | 256 | int bh_uptodate_or_lock(struct buffer_head *bh); |
fdee117e ZY |
257 | int __bh_read(struct buffer_head *bh, blk_opf_t op_flags, bool wait); |
258 | void __bh_read_batch(int nr, struct buffer_head *bhs[], | |
259 | blk_opf_t op_flags, bool force_lock); | |
1da177e4 LT |
260 | |
261 | extern int buffer_heads_over_limit; | |
262 | ||
263 | /* | |
264 | * Generic address_space_operations implementations for buffer_head-backed | |
265 | * address_spaces. | |
266 | */ | |
7ba13abb | 267 | void block_invalidate_folio(struct folio *folio, size_t offset, size_t length); |
1da177e4 LT |
268 | int block_write_full_page(struct page *page, get_block_t *get_block, |
269 | struct writeback_control *wbc); | |
53418a18 | 270 | int __block_write_full_folio(struct inode *inode, struct folio *folio, |
b4bba389 BM |
271 | get_block_t *get_block, struct writeback_control *wbc, |
272 | bh_end_io_t *handler); | |
2c69e205 | 273 | int block_read_full_folio(struct folio *, get_block_t *); |
2e7e80f7 | 274 | bool block_is_partially_uptodate(struct folio *, size_t from, size_t count); |
155130a4 | 275 | int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, |
b3992d1e | 276 | struct page **pagep, get_block_t *get_block); |
6e1db88d CH |
277 | int __block_write_begin(struct page *page, loff_t pos, unsigned len, |
278 | get_block_t *get_block); | |
afddba49 NP |
279 | int block_write_end(struct file *, struct address_space *, |
280 | loff_t, unsigned, unsigned, | |
281 | struct page *, void *); | |
282 | int generic_write_end(struct file *, struct address_space *, | |
283 | loff_t, unsigned, unsigned, | |
284 | struct page *, void *); | |
4a9622f2 | 285 | void folio_zero_new_buffers(struct folio *folio, size_t from, size_t to); |
f892760a | 286 | void clean_page_buffers(struct page *page); |
89e10787 | 287 | int cont_write_begin(struct file *, struct address_space *, loff_t, |
be3bbbc5 | 288 | unsigned, struct page **, void **, |
89e10787 | 289 | get_block_t *, loff_t *); |
05eb0b51 | 290 | int generic_cont_expand_simple(struct inode *inode, loff_t size); |
1da177e4 | 291 | int block_commit_write(struct page *page, unsigned from, unsigned to); |
c2ec175c | 292 | int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, |
54171690 | 293 | get_block_t get_block); |
24da4fab | 294 | /* Convert errno to return value from ->page_mkwrite() call */ |
401b25aa | 295 | static inline vm_fault_t block_page_mkwrite_return(int err) |
24da4fab JK |
296 | { |
297 | if (err == 0) | |
298 | return VM_FAULT_LOCKED; | |
0911d004 | 299 | if (err == -EFAULT || err == -EAGAIN) |
24da4fab JK |
300 | return VM_FAULT_NOPAGE; |
301 | if (err == -ENOMEM) | |
302 | return VM_FAULT_OOM; | |
303 | /* -ENOSPC, -EDQUOT, -EIO ... */ | |
304 | return VM_FAULT_SIGBUS; | |
305 | } | |
1da177e4 | 306 | sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *); |
1da177e4 | 307 | int block_truncate_page(struct address_space *, loff_t, get_block_t *); |
1da177e4 | 308 | |
67235182 MWO |
309 | #ifdef CONFIG_MIGRATION |
310 | extern int buffer_migrate_folio(struct address_space *, | |
311 | struct folio *dst, struct folio *src, enum migrate_mode); | |
312 | extern int buffer_migrate_folio_norefs(struct address_space *, | |
313 | struct folio *dst, struct folio *src, enum migrate_mode); | |
314 | #else | |
315 | #define buffer_migrate_folio NULL | |
316 | #define buffer_migrate_folio_norefs NULL | |
317 | #endif | |
1da177e4 | 318 | |
b6cd0b77 | 319 | void buffer_init(void); |
1da177e4 LT |
320 | |
321 | /* | |
322 | * inline definitions | |
323 | */ | |
324 | ||
1da177e4 LT |
325 | static inline void get_bh(struct buffer_head *bh) |
326 | { | |
327 | atomic_inc(&bh->b_count); | |
328 | } | |
329 | ||
330 | static inline void put_bh(struct buffer_head *bh) | |
331 | { | |
4e857c58 | 332 | smp_mb__before_atomic(); |
1da177e4 LT |
333 | atomic_dec(&bh->b_count); |
334 | } | |
335 | ||
336 | static inline void brelse(struct buffer_head *bh) | |
337 | { | |
338 | if (bh) | |
339 | __brelse(bh); | |
340 | } | |
341 | ||
342 | static inline void bforget(struct buffer_head *bh) | |
343 | { | |
344 | if (bh) | |
345 | __bforget(bh); | |
346 | } | |
347 | ||
348 | static inline struct buffer_head * | |
349 | sb_bread(struct super_block *sb, sector_t block) | |
350 | { | |
3b5e6454 GK |
351 | return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE); |
352 | } | |
353 | ||
354 | static inline struct buffer_head * | |
355 | sb_bread_unmovable(struct super_block *sb, sector_t block) | |
356 | { | |
357 | return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, 0); | |
1da177e4 LT |
358 | } |
359 | ||
360 | static inline void | |
361 | sb_breadahead(struct super_block *sb, sector_t block) | |
362 | { | |
363 | __breadahead(sb->s_bdev, block, sb->s_blocksize); | |
364 | } | |
365 | ||
366 | static inline struct buffer_head * | |
367 | sb_getblk(struct super_block *sb, sector_t block) | |
368 | { | |
3b5e6454 | 369 | return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE); |
1da177e4 LT |
370 | } |
371 | ||
bd7ade3c NB |
372 | |
373 | static inline struct buffer_head * | |
374 | sb_getblk_gfp(struct super_block *sb, sector_t block, gfp_t gfp) | |
375 | { | |
376 | return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, gfp); | |
377 | } | |
378 | ||
1da177e4 LT |
379 | static inline struct buffer_head * |
380 | sb_find_get_block(struct super_block *sb, sector_t block) | |
381 | { | |
382 | return __find_get_block(sb->s_bdev, block, sb->s_blocksize); | |
383 | } | |
384 | ||
385 | static inline void | |
386 | map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block) | |
387 | { | |
388 | set_buffer_mapped(bh); | |
389 | bh->b_bdev = sb->s_bdev; | |
390 | bh->b_blocknr = block; | |
b0cf2321 | 391 | bh->b_size = sb->s_blocksize; |
1da177e4 LT |
392 | } |
393 | ||
1da177e4 LT |
394 | static inline void wait_on_buffer(struct buffer_head *bh) |
395 | { | |
396 | might_sleep(); | |
a9877cc2 | 397 | if (buffer_locked(bh)) |
1da177e4 LT |
398 | __wait_on_buffer(bh); |
399 | } | |
400 | ||
ca5de404 NP |
401 | static inline int trylock_buffer(struct buffer_head *bh) |
402 | { | |
51b07fc3 | 403 | return likely(!test_and_set_bit_lock(BH_Lock, &bh->b_state)); |
ca5de404 NP |
404 | } |
405 | ||
1da177e4 LT |
406 | static inline void lock_buffer(struct buffer_head *bh) |
407 | { | |
408 | might_sleep(); | |
ca5de404 | 409 | if (!trylock_buffer(bh)) |
1da177e4 LT |
410 | __lock_buffer(bh); |
411 | } | |
412 | ||
3b5e6454 GK |
413 | static inline struct buffer_head *getblk_unmovable(struct block_device *bdev, |
414 | sector_t block, | |
415 | unsigned size) | |
416 | { | |
417 | return __getblk_gfp(bdev, block, size, 0); | |
418 | } | |
419 | ||
420 | static inline struct buffer_head *__getblk(struct block_device *bdev, | |
421 | sector_t block, | |
422 | unsigned size) | |
423 | { | |
424 | return __getblk_gfp(bdev, block, size, __GFP_MOVABLE); | |
425 | } | |
426 | ||
fdee117e ZY |
427 | static inline void bh_readahead(struct buffer_head *bh, blk_opf_t op_flags) |
428 | { | |
429 | if (!buffer_uptodate(bh) && trylock_buffer(bh)) { | |
430 | if (!buffer_uptodate(bh)) | |
431 | __bh_read(bh, op_flags, false); | |
432 | else | |
433 | unlock_buffer(bh); | |
434 | } | |
435 | } | |
436 | ||
437 | static inline void bh_read_nowait(struct buffer_head *bh, blk_opf_t op_flags) | |
438 | { | |
439 | if (!bh_uptodate_or_lock(bh)) | |
440 | __bh_read(bh, op_flags, false); | |
441 | } | |
442 | ||
443 | /* Returns 1 if buffer uptodated, 0 on success, and -EIO on error. */ | |
444 | static inline int bh_read(struct buffer_head *bh, blk_opf_t op_flags) | |
445 | { | |
446 | if (bh_uptodate_or_lock(bh)) | |
447 | return 1; | |
448 | return __bh_read(bh, op_flags, true); | |
449 | } | |
450 | ||
451 | static inline void bh_read_batch(int nr, struct buffer_head *bhs[]) | |
452 | { | |
453 | __bh_read_batch(nr, bhs, 0, true); | |
454 | } | |
455 | ||
456 | static inline void bh_readahead_batch(int nr, struct buffer_head *bhs[], | |
457 | blk_opf_t op_flags) | |
458 | { | |
459 | __bh_read_batch(nr, bhs, op_flags, false); | |
460 | } | |
461 | ||
3b5e6454 GK |
462 | /** |
463 | * __bread() - reads a specified block and returns the bh | |
464 | * @bdev: the block_device to read from | |
465 | * @block: number of block | |
466 | * @size: size (in bytes) to read | |
467 | * | |
468 | * Reads a specified block, and returns buffer head that contains it. | |
469 | * The page cache is allocated from movable area so that it can be migrated. | |
470 | * It returns NULL if the block was unreadable. | |
471 | */ | |
472 | static inline struct buffer_head * | |
473 | __bread(struct block_device *bdev, sector_t block, unsigned size) | |
474 | { | |
475 | return __bread_gfp(bdev, block, size, __GFP_MOVABLE); | |
476 | } | |
477 | ||
e621900a | 478 | bool block_dirty_folio(struct address_space *mapping, struct folio *folio); |
9361401e DH |
479 | |
480 | #else /* CONFIG_BLOCK */ | |
481 | ||
482 | static inline void buffer_init(void) {} | |
68189fef | 483 | static inline bool try_to_free_buffers(struct folio *folio) { return true; } |
9361401e DH |
484 | static inline int inode_has_buffers(struct inode *inode) { return 0; } |
485 | static inline void invalidate_inode_buffers(struct inode *inode) {} | |
486 | static inline int remove_inode_buffers(struct inode *inode) { return 1; } | |
487 | static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; } | |
243418e3 | 488 | static inline void invalidate_bh_lrus_cpu(void) {} |
6de522d1 | 489 | static inline bool has_bh_in_lru(int cpu, void *dummy) { return false; } |
d2de7ea4 | 490 | #define buffer_heads_over_limit 0 |
9361401e DH |
491 | |
492 | #endif /* CONFIG_BLOCK */ | |
1da177e4 | 493 | #endif /* _LINUX_BUFFER_HEAD_H */ |