1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_PAGEMAP_H |
3 | #define _LINUX_PAGEMAP_H |
4 | |
5 | /* |
6 | * Copyright 1995 Linus Torvalds |
7 | */ |
8 | #include <linux/mm.h> |
9 | #include <linux/fs.h> |
10 | #include <linux/list.h> |
11 | #include <linux/highmem.h> |
12 | #include <linux/compiler.h> |
13 | #include <linux/uaccess.h> |
14 | #include <linux/gfp.h> |
15 | #include <linux/bitops.h> |
16 | #include <linux/hardirq.h> /* for in_interrupt() */ |
17 | #include <linux/hugetlb_inline.h> |
18 | |
19 | struct folio_batch; |
20 | |
21 | unsigned long invalidate_mapping_pages(struct address_space *mapping, |
22 | pgoff_t start, pgoff_t end); |
23 | |
24 | static inline void invalidate_remote_inode(struct inode *inode) |
25 | { |
26 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
27 | S_ISLNK(inode->i_mode)) |
28 | invalidate_mapping_pages(mapping: inode->i_mapping, start: 0, end: -1); |
29 | } |
30 | int invalidate_inode_pages2(struct address_space *mapping); |
31 | int invalidate_inode_pages2_range(struct address_space *mapping, |
32 | pgoff_t start, pgoff_t end); |
33 | int kiocb_invalidate_pages(struct kiocb *iocb, size_t count); |
34 | void kiocb_invalidate_post_direct_write(struct kiocb *iocb, size_t count); |
35 | int filemap_invalidate_pages(struct address_space *mapping, |
36 | loff_t pos, loff_t end, bool nowait); |
37 | |
38 | int write_inode_now(struct inode *, int sync); |
39 | int filemap_fdatawrite(struct address_space *); |
40 | int filemap_flush(struct address_space *); |
41 | int filemap_fdatawait_keep_errors(struct address_space *mapping); |
42 | int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); |
43 | int filemap_fdatawait_range_keep_errors(struct address_space *mapping, |
44 | loff_t start_byte, loff_t end_byte); |
45 | int filemap_invalidate_inode(struct inode *inode, bool flush, |
46 | loff_t start, loff_t end); |
47 | |
48 | static inline int filemap_fdatawait(struct address_space *mapping) |
49 | { |
50 | return filemap_fdatawait_range(mapping, lstart: 0, LLONG_MAX); |
51 | } |
52 | |
53 | bool filemap_range_has_page(struct address_space *, loff_t lstart, loff_t lend); |
54 | int filemap_write_and_wait_range(struct address_space *mapping, |
55 | loff_t lstart, loff_t lend); |
56 | int __filemap_fdatawrite_range(struct address_space *mapping, |
57 | loff_t start, loff_t end, int sync_mode); |
58 | int filemap_fdatawrite_range(struct address_space *mapping, |
59 | loff_t start, loff_t end); |
60 | int filemap_check_errors(struct address_space *mapping); |
61 | void __filemap_set_wb_err(struct address_space *mapping, int err); |
62 | int filemap_fdatawrite_wbc(struct address_space *mapping, |
63 | struct writeback_control *wbc); |
64 | int kiocb_write_and_wait(struct kiocb *iocb, size_t count); |
65 | |
66 | static inline int filemap_write_and_wait(struct address_space *mapping) |
67 | { |
68 | return filemap_write_and_wait_range(mapping, lstart: 0, LLONG_MAX); |
69 | } |
70 | |
71 | /** |
72 | * filemap_set_wb_err - set a writeback error on an address_space |
73 | * @mapping: mapping in which to set writeback error |
74 | * @err: error to be set in mapping |
75 | * |
76 | * When writeback fails in some way, we must record that error so that |
77 | * userspace can be informed when fsync and the like are called. We endeavor |
78 | * to report errors on any file that was open at the time of the error. Some |
79 | * internal callers also need to know when writeback errors have occurred. |
80 | * |
81 | * When a writeback error occurs, most filesystems will want to call |
82 | * filemap_set_wb_err to record the error in the mapping so that it will be |
83 | * automatically reported whenever fsync is called on the file. |
84 | */ |
85 | static inline void filemap_set_wb_err(struct address_space *mapping, int err) |
86 | { |
87 | /* Fastpath for common case of no error */ |
88 | if (unlikely(err)) |
89 | __filemap_set_wb_err(mapping, err); |
90 | } |
91 | |
92 | /** |
93 | * filemap_check_wb_err - has an error occurred since the mark was sampled? |
94 | * @mapping: mapping to check for writeback errors |
95 | * @since: previously-sampled errseq_t |
96 | * |
97 | * Grab the errseq_t value from the mapping, and see if it has changed "since" |
98 | * the given value was sampled. |
99 | * |
100 | * If it has then report the latest error set, otherwise return 0. |
101 | */ |
102 | static inline int filemap_check_wb_err(struct address_space *mapping, |
103 | errseq_t since) |
104 | { |
105 | return errseq_check(eseq: &mapping->wb_err, since); |
106 | } |
107 | |
108 | /** |
109 | * filemap_sample_wb_err - sample the current errseq_t to test for later errors |
110 | * @mapping: mapping to be sampled |
111 | * |
112 | * Writeback errors are always reported relative to a particular sample point |
113 | * in the past. This function provides those sample points. |
114 | */ |
115 | static inline errseq_t filemap_sample_wb_err(struct address_space *mapping) |
116 | { |
117 | return errseq_sample(eseq: &mapping->wb_err); |
118 | } |
119 | |
120 | /** |
121 | * file_sample_sb_err - sample the current errseq_t to test for later errors |
122 | * @file: file pointer to be sampled |
123 | * |
124 | * Grab the most current superblock-level errseq_t value for the given |
125 | * struct file. |
126 | */ |
127 | static inline errseq_t file_sample_sb_err(struct file *file) |
128 | { |
129 | return errseq_sample(eseq: &file->f_path.dentry->d_sb->s_wb_err); |
130 | } |
131 | |
132 | /* |
133 | * Flush file data before changing attributes. Caller must hold any locks |
134 | * required to prevent further writes to this file until we're done setting |
135 | * flags. |
136 | */ |
137 | static inline int inode_drain_writes(struct inode *inode) |
138 | { |
139 | inode_dio_wait(inode); |
140 | return filemap_write_and_wait(mapping: inode->i_mapping); |
141 | } |
142 | |
143 | static inline bool mapping_empty(struct address_space *mapping) |
144 | { |
145 | return xa_empty(xa: &mapping->i_pages); |
146 | } |
147 | |
148 | /* |
149 | * mapping_shrinkable - test if page cache state allows inode reclaim |
150 | * @mapping: the page cache mapping |
151 | * |
152 | * This checks the mapping's cache state for the pupose of inode |
153 | * reclaim and LRU management. |
154 | * |
155 | * The caller is expected to hold the i_lock, but is not required to |
156 | * hold the i_pages lock, which usually protects cache state. That's |
157 | * because the i_lock and the list_lru lock that protect the inode and |
158 | * its LRU state don't nest inside the irq-safe i_pages lock. |
159 | * |
160 | * Cache deletions are performed under the i_lock, which ensures that |
161 | * when an inode goes empty, it will reliably get queued on the LRU. |
162 | * |
163 | * Cache additions do not acquire the i_lock and may race with this |
164 | * check, in which case we'll report the inode as shrinkable when it |
165 | * has cache pages. This is okay: the shrinker also checks the |
166 | * refcount and the referenced bit, which will be elevated or set in |
167 | * the process of adding new cache pages to an inode. |
168 | */ |
169 | static inline bool mapping_shrinkable(struct address_space *mapping) |
170 | { |
171 | void *head; |
172 | |
173 | /* |
174 | * On highmem systems, there could be lowmem pressure from the |
175 | * inodes before there is highmem pressure from the page |
176 | * cache. Make inodes shrinkable regardless of cache state. |
177 | */ |
178 | if (IS_ENABLED(CONFIG_HIGHMEM)) |
179 | return true; |
180 | |
181 | /* Cache completely empty? Shrink away. */ |
182 | head = rcu_access_pointer(mapping->i_pages.xa_head); |
183 | if (!head) |
184 | return true; |
185 | |
186 | /* |
187 | * The xarray stores single offset-0 entries directly in the |
188 | * head pointer, which allows non-resident page cache entries |
189 | * to escape the shadow shrinker's list of xarray nodes. The |
190 | * inode shrinker needs to pick them up under memory pressure. |
191 | */ |
192 | if (!xa_is_node(entry: head) && xa_is_value(entry: head)) |
193 | return true; |
194 | |
195 | return false; |
196 | } |
197 | |
198 | /* |
199 | * Bits in mapping->flags. |
200 | */ |
201 | enum mapping_flags { |
202 | AS_EIO = 0, /* IO error on async write */ |
203 | AS_ENOSPC = 1, /* ENOSPC on async write */ |
204 | AS_MM_ALL_LOCKS = 2, /* under mm_take_all_locks() */ |
205 | AS_UNEVICTABLE = 3, /* e.g., ramdisk, SHM_LOCK */ |
206 | AS_EXITING = 4, /* final truncate in progress */ |
207 | /* writeback related tags are not used */ |
208 | AS_NO_WRITEBACK_TAGS = 5, |
209 | AS_RELEASE_ALWAYS = 6, /* Call ->release_folio(), even if no private data */ |
210 | AS_STABLE_WRITES = 7, /* must wait for writeback before modifying |
211 | folio contents */ |
212 | AS_INACCESSIBLE = 8, /* Do not attempt direct R/W access to the mapping */ |
213 | AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM = 9, |
214 | /* Bits 16-25 are used for FOLIO_ORDER */ |
215 | AS_FOLIO_ORDER_BITS = 5, |
216 | AS_FOLIO_ORDER_MIN = 16, |
217 | AS_FOLIO_ORDER_MAX = AS_FOLIO_ORDER_MIN + AS_FOLIO_ORDER_BITS, |
218 | }; |
219 | |
220 | #define AS_FOLIO_ORDER_BITS_MASK ((1u << AS_FOLIO_ORDER_BITS) - 1) |
221 | #define AS_FOLIO_ORDER_MIN_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MIN) |
222 | #define AS_FOLIO_ORDER_MAX_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MAX) |
223 | #define AS_FOLIO_ORDER_MASK (AS_FOLIO_ORDER_MIN_MASK | AS_FOLIO_ORDER_MAX_MASK) |
224 | |
225 | /** |
226 | * mapping_set_error - record a writeback error in the address_space |
227 | * @mapping: the mapping in which an error should be set |
228 | * @error: the error to set in the mapping |
229 | * |
230 | * When writeback fails in some way, we must record that error so that |
231 | * userspace can be informed when fsync and the like are called. We endeavor |
232 | * to report errors on any file that was open at the time of the error. Some |
233 | * internal callers also need to know when writeback errors have occurred. |
234 | * |
235 | * When a writeback error occurs, most filesystems will want to call |
236 | * mapping_set_error to record the error in the mapping so that it can be |
237 | * reported when the application calls fsync(2). |
238 | */ |
239 | static inline void mapping_set_error(struct address_space *mapping, int error) |
240 | { |
241 | if (likely(!error)) |
242 | return; |
243 | |
244 | /* Record in wb_err for checkers using errseq_t based tracking */ |
245 | __filemap_set_wb_err(mapping, err: error); |
246 | |
247 | /* Record it in superblock */ |
248 | if (mapping->host) |
249 | errseq_set(eseq: &mapping->host->i_sb->s_wb_err, err: error); |
250 | |
251 | /* Record it in flags for now, for legacy callers */ |
252 | if (error == -ENOSPC) |
253 | set_bit(nr: AS_ENOSPC, addr: &mapping->flags); |
254 | else |
255 | set_bit(nr: AS_EIO, addr: &mapping->flags); |
256 | } |
257 | |
258 | static inline void mapping_set_unevictable(struct address_space *mapping) |
259 | { |
260 | set_bit(nr: AS_UNEVICTABLE, addr: &mapping->flags); |
261 | } |
262 | |
263 | static inline void mapping_clear_unevictable(struct address_space *mapping) |
264 | { |
265 | clear_bit(nr: AS_UNEVICTABLE, addr: &mapping->flags); |
266 | } |
267 | |
268 | static inline bool mapping_unevictable(struct address_space *mapping) |
269 | { |
270 | return mapping && test_bit(AS_UNEVICTABLE, &mapping->flags); |
271 | } |
272 | |
273 | static inline void mapping_set_exiting(struct address_space *mapping) |
274 | { |
275 | set_bit(nr: AS_EXITING, addr: &mapping->flags); |
276 | } |
277 | |
278 | static inline int mapping_exiting(struct address_space *mapping) |
279 | { |
280 | return test_bit(AS_EXITING, &mapping->flags); |
281 | } |
282 | |
283 | static inline void mapping_set_no_writeback_tags(struct address_space *mapping) |
284 | { |
285 | set_bit(nr: AS_NO_WRITEBACK_TAGS, addr: &mapping->flags); |
286 | } |
287 | |
288 | static inline int mapping_use_writeback_tags(struct address_space *mapping) |
289 | { |
290 | return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags); |
291 | } |
292 | |
293 | static inline bool mapping_release_always(const struct address_space *mapping) |
294 | { |
295 | return test_bit(AS_RELEASE_ALWAYS, &mapping->flags); |
296 | } |
297 | |
298 | static inline void mapping_set_release_always(struct address_space *mapping) |
299 | { |
300 | set_bit(nr: AS_RELEASE_ALWAYS, addr: &mapping->flags); |
301 | } |
302 | |
303 | static inline void mapping_clear_release_always(struct address_space *mapping) |
304 | { |
305 | clear_bit(nr: AS_RELEASE_ALWAYS, addr: &mapping->flags); |
306 | } |
307 | |
308 | static inline bool mapping_stable_writes(const struct address_space *mapping) |
309 | { |
310 | return test_bit(AS_STABLE_WRITES, &mapping->flags); |
311 | } |
312 | |
313 | static inline void mapping_set_stable_writes(struct address_space *mapping) |
314 | { |
315 | set_bit(nr: AS_STABLE_WRITES, addr: &mapping->flags); |
316 | } |
317 | |
318 | static inline void mapping_clear_stable_writes(struct address_space *mapping) |
319 | { |
320 | clear_bit(nr: AS_STABLE_WRITES, addr: &mapping->flags); |
321 | } |
322 | |
323 | static inline void mapping_set_inaccessible(struct address_space *mapping) |
324 | { |
325 | /* |
326 | * It's expected inaccessible mappings are also unevictable. Compaction |
327 | * migrate scanner (isolate_migratepages_block()) relies on this to |
328 | * reduce page locking. |
329 | */ |
330 | set_bit(nr: AS_UNEVICTABLE, addr: &mapping->flags); |
331 | set_bit(nr: AS_INACCESSIBLE, addr: &mapping->flags); |
332 | } |
333 | |
334 | static inline bool mapping_inaccessible(struct address_space *mapping) |
335 | { |
336 | return test_bit(AS_INACCESSIBLE, &mapping->flags); |
337 | } |
338 | |
339 | static inline void mapping_set_writeback_may_deadlock_on_reclaim(struct address_space *mapping) |
340 | { |
341 | set_bit(nr: AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM, addr: &mapping->flags); |
342 | } |
343 | |
344 | static inline bool mapping_writeback_may_deadlock_on_reclaim(struct address_space *mapping) |
345 | { |
346 | return test_bit(AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM, &mapping->flags); |
347 | } |
348 | |
349 | static inline gfp_t mapping_gfp_mask(struct address_space * mapping) |
350 | { |
351 | return mapping->gfp_mask; |
352 | } |
353 | |
354 | /* Restricts the given gfp_mask to what the mapping allows. */ |
355 | static inline gfp_t mapping_gfp_constraint(struct address_space *mapping, |
356 | gfp_t gfp_mask) |
357 | { |
358 | return mapping_gfp_mask(mapping) & gfp_mask; |
359 | } |
360 | |
361 | /* |
362 | * This is non-atomic. Only to be used before the mapping is activated. |
363 | * Probably needs a barrier... |
364 | */ |
365 | static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) |
366 | { |
367 | m->gfp_mask = mask; |
368 | } |
369 | |
370 | /* |
371 | * There are some parts of the kernel which assume that PMD entries |
372 | * are exactly HPAGE_PMD_ORDER. Those should be fixed, but until then, |
373 | * limit the maximum allocation order to PMD size. I'm not aware of any |
374 | * assumptions about maximum order if THP are disabled, but 8 seems like |
375 | * a good order (that's 1MB if you're using 4kB pages) |
376 | */ |
377 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
378 | #define PREFERRED_MAX_PAGECACHE_ORDER HPAGE_PMD_ORDER |
379 | #else |
380 | #define PREFERRED_MAX_PAGECACHE_ORDER 8 |
381 | #endif |
382 | |
383 | /* |
384 | * xas_split_alloc() does not support arbitrary orders. This implies no |
385 | * 512MB THP on ARM64 with 64KB base page size. |
386 | */ |
387 | #define MAX_XAS_ORDER (XA_CHUNK_SHIFT * 2 - 1) |
388 | #define MAX_PAGECACHE_ORDER min(MAX_XAS_ORDER, PREFERRED_MAX_PAGECACHE_ORDER) |
389 | |
390 | /* |
391 | * mapping_max_folio_size_supported() - Check the max folio size supported |
392 | * |
393 | * The filesystem should call this function at mount time if there is a |
394 | * requirement on the folio mapping size in the page cache. |
395 | */ |
396 | static inline size_t mapping_max_folio_size_supported(void) |
397 | { |
398 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
399 | return 1U << (PAGE_SHIFT + MAX_PAGECACHE_ORDER); |
400 | return PAGE_SIZE; |
401 | } |
402 | |
403 | /* |
404 | * mapping_set_folio_order_range() - Set the orders supported by a file. |
405 | * @mapping: The address space of the file. |
406 | * @min: Minimum folio order (between 0-MAX_PAGECACHE_ORDER inclusive). |
407 | * @max: Maximum folio order (between @min-MAX_PAGECACHE_ORDER inclusive). |
408 | * |
409 | * The filesystem should call this function in its inode constructor to |
410 | * indicate which base size (min) and maximum size (max) of folio the VFS |
411 | * can use to cache the contents of the file. This should only be used |
412 | * if the filesystem needs special handling of folio sizes (ie there is |
413 | * something the core cannot know). |
414 | * Do not tune it based on, eg, i_size. |
415 | * |
416 | * Context: This should not be called while the inode is active as it |
417 | * is non-atomic. |
418 | */ |
419 | static inline void mapping_set_folio_order_range(struct address_space *mapping, |
420 | unsigned int min, |
421 | unsigned int max) |
422 | { |
423 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
424 | return; |
425 | |
426 | if (min > MAX_PAGECACHE_ORDER) |
427 | min = MAX_PAGECACHE_ORDER; |
428 | |
429 | if (max > MAX_PAGECACHE_ORDER) |
430 | max = MAX_PAGECACHE_ORDER; |
431 | |
432 | if (max < min) |
433 | max = min; |
434 | |
435 | mapping->flags = (mapping->flags & ~AS_FOLIO_ORDER_MASK) | |
436 | (min << AS_FOLIO_ORDER_MIN) | (max << AS_FOLIO_ORDER_MAX); |
437 | } |
438 | |
439 | static inline void mapping_set_folio_min_order(struct address_space *mapping, |
440 | unsigned int min) |
441 | { |
442 | mapping_set_folio_order_range(mapping, min, MAX_PAGECACHE_ORDER); |
443 | } |
444 | |
445 | /** |
446 | * mapping_set_large_folios() - Indicate the file supports large folios. |
447 | * @mapping: The address space of the file. |
448 | * |
449 | * The filesystem should call this function in its inode constructor to |
450 | * indicate that the VFS can use large folios to cache the contents of |
451 | * the file. |
452 | * |
453 | * Context: This should not be called while the inode is active as it |
454 | * is non-atomic. |
455 | */ |
456 | static inline void mapping_set_large_folios(struct address_space *mapping) |
457 | { |
458 | mapping_set_folio_order_range(mapping, min: 0, MAX_PAGECACHE_ORDER); |
459 | } |
460 | |
461 | static inline unsigned int |
462 | mapping_max_folio_order(const struct address_space *mapping) |
463 | { |
464 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
465 | return 0; |
466 | return (mapping->flags & AS_FOLIO_ORDER_MAX_MASK) >> AS_FOLIO_ORDER_MAX; |
467 | } |
468 | |
469 | static inline unsigned int |
470 | mapping_min_folio_order(const struct address_space *mapping) |
471 | { |
472 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
473 | return 0; |
474 | return (mapping->flags & AS_FOLIO_ORDER_MIN_MASK) >> AS_FOLIO_ORDER_MIN; |
475 | } |
476 | |
477 | static inline unsigned long |
478 | mapping_min_folio_nrpages(struct address_space *mapping) |
479 | { |
480 | return 1UL << mapping_min_folio_order(mapping); |
481 | } |
482 | |
483 | /** |
484 | * mapping_align_index() - Align index for this mapping. |
485 | * @mapping: The address_space. |
486 | * @index: The page index. |
487 | * |
488 | * The index of a folio must be naturally aligned. If you are adding a |
489 | * new folio to the page cache and need to know what index to give it, |
490 | * call this function. |
491 | */ |
492 | static inline pgoff_t mapping_align_index(struct address_space *mapping, |
493 | pgoff_t index) |
494 | { |
495 | return round_down(index, mapping_min_folio_nrpages(mapping)); |
496 | } |
497 | |
498 | /* |
499 | * Large folio support currently depends on THP. These dependencies are |
500 | * being worked on but are not yet fixed. |
501 | */ |
502 | static inline bool mapping_large_folio_support(struct address_space *mapping) |
503 | { |
504 | /* AS_FOLIO_ORDER is only reasonable for pagecache folios */ |
505 | VM_WARN_ONCE((unsigned long)mapping & PAGE_MAPPING_ANON, |
506 | "Anonymous mapping always supports large folio" ); |
507 | |
508 | return mapping_max_folio_order(mapping) > 0; |
509 | } |
510 | |
511 | /* Return the maximum folio size for this pagecache mapping, in bytes. */ |
512 | static inline size_t mapping_max_folio_size(const struct address_space *mapping) |
513 | { |
514 | return PAGE_SIZE << mapping_max_folio_order(mapping); |
515 | } |
516 | |
517 | static inline int filemap_nr_thps(struct address_space *mapping) |
518 | { |
519 | #ifdef CONFIG_READ_ONLY_THP_FOR_FS |
520 | return atomic_read(v: &mapping->nr_thps); |
521 | #else |
522 | return 0; |
523 | #endif |
524 | } |
525 | |
526 | static inline void filemap_nr_thps_inc(struct address_space *mapping) |
527 | { |
528 | #ifdef CONFIG_READ_ONLY_THP_FOR_FS |
529 | if (!mapping_large_folio_support(mapping)) |
530 | atomic_inc(v: &mapping->nr_thps); |
531 | #else |
532 | WARN_ON_ONCE(mapping_large_folio_support(mapping) == 0); |
533 | #endif |
534 | } |
535 | |
536 | static inline void filemap_nr_thps_dec(struct address_space *mapping) |
537 | { |
538 | #ifdef CONFIG_READ_ONLY_THP_FOR_FS |
539 | if (!mapping_large_folio_support(mapping)) |
540 | atomic_dec(v: &mapping->nr_thps); |
541 | #else |
542 | WARN_ON_ONCE(mapping_large_folio_support(mapping) == 0); |
543 | #endif |
544 | } |
545 | |
546 | struct address_space *folio_mapping(struct folio *); |
547 | |
548 | /** |
549 | * folio_flush_mapping - Find the file mapping this folio belongs to. |
550 | * @folio: The folio. |
551 | * |
552 | * For folios which are in the page cache, return the mapping that this |
553 | * page belongs to. Anonymous folios return NULL, even if they're in |
554 | * the swap cache. Other kinds of folio also return NULL. |
555 | * |
556 | * This is ONLY used by architecture cache flushing code. If you aren't |
557 | * writing cache flushing code, you want either folio_mapping() or |
558 | * folio_file_mapping(). |
559 | */ |
560 | static inline struct address_space *folio_flush_mapping(struct folio *folio) |
561 | { |
562 | if (unlikely(folio_test_swapcache(folio))) |
563 | return NULL; |
564 | |
565 | return folio_mapping(folio); |
566 | } |
567 | |
568 | /** |
569 | * folio_inode - Get the host inode for this folio. |
570 | * @folio: The folio. |
571 | * |
572 | * For folios which are in the page cache, return the inode that this folio |
573 | * belongs to. |
574 | * |
575 | * Do not call this for folios which aren't in the page cache. |
576 | */ |
577 | static inline struct inode *folio_inode(struct folio *folio) |
578 | { |
579 | return folio->mapping->host; |
580 | } |
581 | |
582 | /** |
583 | * folio_attach_private - Attach private data to a folio. |
584 | * @folio: Folio to attach data to. |
585 | * @data: Data to attach to folio. |
586 | * |
587 | * Attaching private data to a folio increments the page's reference count. |
588 | * The data must be detached before the folio will be freed. |
589 | */ |
590 | static inline void folio_attach_private(struct folio *folio, void *data) |
591 | { |
592 | folio_get(folio); |
593 | folio->private = data; |
594 | folio_set_private(folio); |
595 | } |
596 | |
597 | /** |
598 | * folio_change_private - Change private data on a folio. |
599 | * @folio: Folio to change the data on. |
600 | * @data: Data to set on the folio. |
601 | * |
602 | * Change the private data attached to a folio and return the old |
603 | * data. The page must previously have had data attached and the data |
604 | * must be detached before the folio will be freed. |
605 | * |
606 | * Return: Data that was previously attached to the folio. |
607 | */ |
608 | static inline void *folio_change_private(struct folio *folio, void *data) |
609 | { |
610 | void *old = folio_get_private(folio); |
611 | |
612 | folio->private = data; |
613 | return old; |
614 | } |
615 | |
616 | /** |
617 | * folio_detach_private - Detach private data from a folio. |
618 | * @folio: Folio to detach data from. |
619 | * |
620 | * Removes the data that was previously attached to the folio and decrements |
621 | * the refcount on the page. |
622 | * |
623 | * Return: Data that was attached to the folio. |
624 | */ |
625 | static inline void *folio_detach_private(struct folio *folio) |
626 | { |
627 | void *data = folio_get_private(folio); |
628 | |
629 | if (!folio_test_private(folio)) |
630 | return NULL; |
631 | folio_clear_private(folio); |
632 | folio->private = NULL; |
633 | folio_put(folio); |
634 | |
635 | return data; |
636 | } |
637 | |
638 | static inline void attach_page_private(struct page *page, void *data) |
639 | { |
640 | folio_attach_private(page_folio(page), data); |
641 | } |
642 | |
643 | static inline void *detach_page_private(struct page *page) |
644 | { |
645 | return folio_detach_private(page_folio(page)); |
646 | } |
647 | |
648 | #ifdef CONFIG_NUMA |
649 | struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order); |
650 | #else |
651 | static inline struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order) |
652 | { |
653 | return folio_alloc_noprof(gfp, order); |
654 | } |
655 | #endif |
656 | |
657 | #define filemap_alloc_folio(...) \ |
658 | alloc_hooks(filemap_alloc_folio_noprof(__VA_ARGS__)) |
659 | |
660 | static inline struct page *__page_cache_alloc(gfp_t gfp) |
661 | { |
662 | return &filemap_alloc_folio(gfp, 0)->page; |
663 | } |
664 | |
665 | static inline gfp_t readahead_gfp_mask(struct address_space *x) |
666 | { |
667 | return mapping_gfp_mask(mapping: x) | __GFP_NORETRY | __GFP_NOWARN; |
668 | } |
669 | |
670 | typedef int filler_t(struct file *, struct folio *); |
671 | |
672 | pgoff_t page_cache_next_miss(struct address_space *mapping, |
673 | pgoff_t index, unsigned long max_scan); |
674 | pgoff_t page_cache_prev_miss(struct address_space *mapping, |
675 | pgoff_t index, unsigned long max_scan); |
676 | |
677 | /** |
678 | * typedef fgf_t - Flags for getting folios from the page cache. |
679 | * |
680 | * Most users of the page cache will not need to use these flags; |
681 | * there are convenience functions such as filemap_get_folio() and |
682 | * filemap_lock_folio(). For users which need more control over exactly |
683 | * what is done with the folios, these flags to __filemap_get_folio() |
684 | * are available. |
685 | * |
686 | * * %FGP_ACCESSED - The folio will be marked accessed. |
687 | * * %FGP_LOCK - The folio is returned locked. |
688 | * * %FGP_CREAT - If no folio is present then a new folio is allocated, |
689 | * added to the page cache and the VM's LRU list. The folio is |
690 | * returned locked. |
691 | * * %FGP_FOR_MMAP - The caller wants to do its own locking dance if the |
692 | * folio is already in cache. If the folio was allocated, unlock it |
693 | * before returning so the caller can do the same dance. |
694 | * * %FGP_WRITE - The folio will be written to by the caller. |
695 | * * %FGP_NOFS - __GFP_FS will get cleared in gfp. |
696 | * * %FGP_NOWAIT - Don't block on the folio lock. |
697 | * * %FGP_STABLE - Wait for the folio to be stable (finished writeback) |
698 | * * %FGP_DONTCACHE - Uncached buffered IO |
699 | * * %FGP_WRITEBEGIN - The flags to use in a filesystem write_begin() |
700 | * implementation. |
701 | */ |
702 | typedef unsigned int __bitwise fgf_t; |
703 | |
704 | #define FGP_ACCESSED ((__force fgf_t)0x00000001) |
705 | #define FGP_LOCK ((__force fgf_t)0x00000002) |
706 | #define FGP_CREAT ((__force fgf_t)0x00000004) |
707 | #define FGP_WRITE ((__force fgf_t)0x00000008) |
708 | #define FGP_NOFS ((__force fgf_t)0x00000010) |
709 | #define FGP_NOWAIT ((__force fgf_t)0x00000020) |
710 | #define FGP_FOR_MMAP ((__force fgf_t)0x00000040) |
711 | #define FGP_STABLE ((__force fgf_t)0x00000080) |
712 | #define FGP_DONTCACHE ((__force fgf_t)0x00000100) |
713 | #define FGF_GET_ORDER(fgf) (((__force unsigned)fgf) >> 26) /* top 6 bits */ |
714 | |
715 | #define FGP_WRITEBEGIN (FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE) |
716 | |
717 | static inline unsigned int filemap_get_order(size_t size) |
718 | { |
719 | unsigned int shift = ilog2(size); |
720 | |
721 | if (shift <= PAGE_SHIFT) |
722 | return 0; |
723 | |
724 | return shift - PAGE_SHIFT; |
725 | } |
726 | |
727 | /** |
728 | * fgf_set_order - Encode a length in the fgf_t flags. |
729 | * @size: The suggested size of the folio to create. |
730 | * |
731 | * The caller of __filemap_get_folio() can use this to suggest a preferred |
732 | * size for the folio that is created. If there is already a folio at |
733 | * the index, it will be returned, no matter what its size. If a folio |
734 | * is freshly created, it may be of a different size than requested |
735 | * due to alignment constraints, memory pressure, or the presence of |
736 | * other folios at nearby indices. |
737 | */ |
738 | static inline fgf_t fgf_set_order(size_t size) |
739 | { |
740 | unsigned int order = filemap_get_order(size); |
741 | |
742 | if (!order) |
743 | return 0; |
744 | return (__force fgf_t)(order << 26); |
745 | } |
746 | |
747 | void *filemap_get_entry(struct address_space *mapping, pgoff_t index); |
748 | struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, |
749 | fgf_t fgp_flags, gfp_t gfp); |
750 | struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, |
751 | fgf_t fgp_flags, gfp_t gfp); |
752 | |
753 | /** |
754 | * filemap_get_folio - Find and get a folio. |
755 | * @mapping: The address_space to search. |
756 | * @index: The page index. |
757 | * |
758 | * Looks up the page cache entry at @mapping & @index. If a folio is |
759 | * present, it is returned with an increased refcount. |
760 | * |
761 | * Return: A folio or ERR_PTR(-ENOENT) if there is no folio in the cache for |
762 | * this index. Will not return a shadow, swap or DAX entry. |
763 | */ |
764 | static inline struct folio *filemap_get_folio(struct address_space *mapping, |
765 | pgoff_t index) |
766 | { |
767 | return __filemap_get_folio(mapping, index, fgp_flags: 0, gfp: 0); |
768 | } |
769 | |
770 | /** |
771 | * filemap_lock_folio - Find and lock a folio. |
772 | * @mapping: The address_space to search. |
773 | * @index: The page index. |
774 | * |
775 | * Looks up the page cache entry at @mapping & @index. If a folio is |
776 | * present, it is returned locked with an increased refcount. |
777 | * |
778 | * Context: May sleep. |
779 | * Return: A folio or ERR_PTR(-ENOENT) if there is no folio in the cache for |
780 | * this index. Will not return a shadow, swap or DAX entry. |
781 | */ |
782 | static inline struct folio *filemap_lock_folio(struct address_space *mapping, |
783 | pgoff_t index) |
784 | { |
785 | return __filemap_get_folio(mapping, index, FGP_LOCK, gfp: 0); |
786 | } |
787 | |
788 | /** |
789 | * filemap_grab_folio - grab a folio from the page cache |
790 | * @mapping: The address space to search |
791 | * @index: The page index |
792 | * |
793 | * Looks up the page cache entry at @mapping & @index. If no folio is found, |
794 | * a new folio is created. The folio is locked, marked as accessed, and |
795 | * returned. |
796 | * |
797 | * Return: A found or created folio. ERR_PTR(-ENOMEM) if no folio is found |
798 | * and failed to create a folio. |
799 | */ |
800 | static inline struct folio *filemap_grab_folio(struct address_space *mapping, |
801 | pgoff_t index) |
802 | { |
803 | return __filemap_get_folio(mapping, index, |
804 | FGP_LOCK | FGP_ACCESSED | FGP_CREAT, |
805 | gfp: mapping_gfp_mask(mapping)); |
806 | } |
807 | |
808 | /** |
809 | * find_get_page - find and get a page reference |
810 | * @mapping: the address_space to search |
811 | * @offset: the page index |
812 | * |
813 | * Looks up the page cache slot at @mapping & @offset. If there is a |
814 | * page cache page, it is returned with an increased refcount. |
815 | * |
816 | * Otherwise, %NULL is returned. |
817 | */ |
818 | static inline struct page *find_get_page(struct address_space *mapping, |
819 | pgoff_t offset) |
820 | { |
821 | return pagecache_get_page(mapping, index: offset, fgp_flags: 0, gfp: 0); |
822 | } |
823 | |
824 | static inline struct page *find_get_page_flags(struct address_space *mapping, |
825 | pgoff_t offset, fgf_t fgp_flags) |
826 | { |
827 | return pagecache_get_page(mapping, index: offset, fgp_flags, gfp: 0); |
828 | } |
829 | |
830 | /** |
831 | * find_lock_page - locate, pin and lock a pagecache page |
832 | * @mapping: the address_space to search |
833 | * @index: the page index |
834 | * |
835 | * Looks up the page cache entry at @mapping & @index. If there is a |
836 | * page cache page, it is returned locked and with an increased |
837 | * refcount. |
838 | * |
839 | * Context: May sleep. |
840 | * Return: A struct page or %NULL if there is no page in the cache for this |
841 | * index. |
842 | */ |
843 | static inline struct page *find_lock_page(struct address_space *mapping, |
844 | pgoff_t index) |
845 | { |
846 | return pagecache_get_page(mapping, index, FGP_LOCK, gfp: 0); |
847 | } |
848 | |
849 | /** |
850 | * find_or_create_page - locate or add a pagecache page |
851 | * @mapping: the page's address_space |
852 | * @index: the page's index into the mapping |
853 | * @gfp_mask: page allocation mode |
854 | * |
855 | * Looks up the page cache slot at @mapping & @offset. If there is a |
856 | * page cache page, it is returned locked and with an increased |
857 | * refcount. |
858 | * |
859 | * If the page is not present, a new page is allocated using @gfp_mask |
860 | * and added to the page cache and the VM's LRU list. The page is |
861 | * returned locked and with an increased refcount. |
862 | * |
863 | * On memory exhaustion, %NULL is returned. |
864 | * |
865 | * find_or_create_page() may sleep, even if @gfp_flags specifies an |
866 | * atomic allocation! |
867 | */ |
868 | static inline struct page *find_or_create_page(struct address_space *mapping, |
869 | pgoff_t index, gfp_t gfp_mask) |
870 | { |
871 | return pagecache_get_page(mapping, index, |
872 | FGP_LOCK|FGP_ACCESSED|FGP_CREAT, |
873 | gfp: gfp_mask); |
874 | } |
875 | |
876 | /** |
877 | * grab_cache_page_nowait - returns locked page at given index in given cache |
878 | * @mapping: target address_space |
879 | * @index: the page index |
880 | * |
881 | * Same as grab_cache_page(), but do not wait if the page is unavailable. |
882 | * This is intended for speculative data generators, where the data can |
883 | * be regenerated if the page couldn't be grabbed. This routine should |
884 | * be safe to call while holding the lock for another page. |
885 | * |
886 | * Clear __GFP_FS when allocating the page to avoid recursion into the fs |
887 | * and deadlock against the caller's locked page. |
888 | */ |
889 | static inline struct page *grab_cache_page_nowait(struct address_space *mapping, |
890 | pgoff_t index) |
891 | { |
892 | return pagecache_get_page(mapping, index, |
893 | FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT, |
894 | gfp: mapping_gfp_mask(mapping)); |
895 | } |
896 | |
897 | /** |
898 | * folio_next_index - Get the index of the next folio. |
899 | * @folio: The current folio. |
900 | * |
901 | * Return: The index of the folio which follows this folio in the file. |
902 | */ |
903 | static inline pgoff_t folio_next_index(struct folio *folio) |
904 | { |
905 | return folio->index + folio_nr_pages(folio); |
906 | } |
907 | |
908 | /** |
909 | * folio_file_page - The page for a particular index. |
910 | * @folio: The folio which contains this index. |
911 | * @index: The index we want to look up. |
912 | * |
913 | * Sometimes after looking up a folio in the page cache, we need to |
914 | * obtain the specific page for an index (eg a page fault). |
915 | * |
916 | * Return: The page containing the file data for this index. |
917 | */ |
918 | static inline struct page *folio_file_page(struct folio *folio, pgoff_t index) |
919 | { |
920 | return folio_page(folio, index & (folio_nr_pages(folio) - 1)); |
921 | } |
922 | |
923 | /** |
924 | * folio_contains - Does this folio contain this index? |
925 | * @folio: The folio. |
926 | * @index: The page index within the file. |
927 | * |
928 | * Context: The caller should have the folio locked and ensure |
929 | * e.g., shmem did not move this folio to the swap cache. |
930 | * Return: true or false. |
931 | */ |
932 | static inline bool folio_contains(struct folio *folio, pgoff_t index) |
933 | { |
934 | VM_WARN_ON_ONCE_FOLIO(folio_test_swapcache(folio), folio); |
935 | return index - folio->index < folio_nr_pages(folio); |
936 | } |
937 | |
938 | unsigned filemap_get_folios(struct address_space *mapping, pgoff_t *start, |
939 | pgoff_t end, struct folio_batch *fbatch); |
940 | unsigned filemap_get_folios_contig(struct address_space *mapping, |
941 | pgoff_t *start, pgoff_t end, struct folio_batch *fbatch); |
942 | unsigned filemap_get_folios_tag(struct address_space *mapping, pgoff_t *start, |
943 | pgoff_t end, xa_mark_t tag, struct folio_batch *fbatch); |
944 | |
945 | /* |
946 | * Returns locked page at given index in given cache, creating it if needed. |
947 | */ |
948 | static inline struct page *grab_cache_page(struct address_space *mapping, |
949 | pgoff_t index) |
950 | { |
951 | return find_or_create_page(mapping, index, gfp_mask: mapping_gfp_mask(mapping)); |
952 | } |
953 | |
954 | struct folio *read_cache_folio(struct address_space *, pgoff_t index, |
955 | filler_t *filler, struct file *file); |
956 | struct folio *mapping_read_folio_gfp(struct address_space *, pgoff_t index, |
957 | gfp_t flags); |
958 | struct page *read_cache_page(struct address_space *, pgoff_t index, |
959 | filler_t *filler, struct file *file); |
960 | extern struct page * read_cache_page_gfp(struct address_space *mapping, |
961 | pgoff_t index, gfp_t gfp_mask); |
962 | |
963 | static inline struct page *read_mapping_page(struct address_space *mapping, |
964 | pgoff_t index, struct file *file) |
965 | { |
966 | return read_cache_page(mapping, index, NULL, file); |
967 | } |
968 | |
969 | static inline struct folio *read_mapping_folio(struct address_space *mapping, |
970 | pgoff_t index, struct file *file) |
971 | { |
972 | return read_cache_folio(mapping, index, NULL, file); |
973 | } |
974 | |
975 | /** |
976 | * page_pgoff - Calculate the logical page offset of this page. |
977 | * @folio: The folio containing this page. |
978 | * @page: The page which we need the offset of. |
979 | * |
980 | * For file pages, this is the offset from the beginning of the file |
981 | * in units of PAGE_SIZE. For anonymous pages, this is the offset from |
982 | * the beginning of the anon_vma in units of PAGE_SIZE. This will |
983 | * return nonsense for KSM pages. |
984 | * |
985 | * Context: Caller must have a reference on the folio or otherwise |
986 | * prevent it from being split or freed. |
987 | * |
988 | * Return: The offset in units of PAGE_SIZE. |
989 | */ |
990 | static inline pgoff_t page_pgoff(const struct folio *folio, |
991 | const struct page *page) |
992 | { |
993 | return folio->index + folio_page_idx(folio, page); |
994 | } |
995 | |
996 | /** |
997 | * folio_pos - Returns the byte position of this folio in its file. |
998 | * @folio: The folio. |
999 | */ |
1000 | static inline loff_t folio_pos(const struct folio *folio) |
1001 | { |
1002 | return ((loff_t)folio->index) * PAGE_SIZE; |
1003 | } |
1004 | |
1005 | /* |
1006 | * Return byte-offset into filesystem object for page. |
1007 | */ |
1008 | static inline loff_t page_offset(struct page *page) |
1009 | { |
1010 | struct folio *folio = page_folio(page); |
1011 | |
1012 | return folio_pos(folio) + folio_page_idx(folio, page) * PAGE_SIZE; |
1013 | } |
1014 | |
1015 | /* |
1016 | * Get the offset in PAGE_SIZE (even for hugetlb folios). |
1017 | */ |
1018 | static inline pgoff_t folio_pgoff(struct folio *folio) |
1019 | { |
1020 | return folio->index; |
1021 | } |
1022 | |
1023 | static inline pgoff_t linear_page_index(struct vm_area_struct *vma, |
1024 | unsigned long address) |
1025 | { |
1026 | pgoff_t pgoff; |
1027 | pgoff = (address - vma->vm_start) >> PAGE_SHIFT; |
1028 | pgoff += vma->vm_pgoff; |
1029 | return pgoff; |
1030 | } |
1031 | |
1032 | struct wait_page_key { |
1033 | struct folio *folio; |
1034 | int bit_nr; |
1035 | int page_match; |
1036 | }; |
1037 | |
1038 | struct wait_page_queue { |
1039 | struct folio *folio; |
1040 | int bit_nr; |
1041 | wait_queue_entry_t wait; |
1042 | }; |
1043 | |
1044 | static inline bool wake_page_match(struct wait_page_queue *wait_page, |
1045 | struct wait_page_key *key) |
1046 | { |
1047 | if (wait_page->folio != key->folio) |
1048 | return false; |
1049 | key->page_match = 1; |
1050 | |
1051 | if (wait_page->bit_nr != key->bit_nr) |
1052 | return false; |
1053 | |
1054 | return true; |
1055 | } |
1056 | |
1057 | void __folio_lock(struct folio *folio); |
1058 | int __folio_lock_killable(struct folio *folio); |
1059 | vm_fault_t __folio_lock_or_retry(struct folio *folio, struct vm_fault *vmf); |
1060 | void unlock_page(struct page *page); |
1061 | void folio_unlock(struct folio *folio); |
1062 | |
1063 | /** |
1064 | * folio_trylock() - Attempt to lock a folio. |
1065 | * @folio: The folio to attempt to lock. |
1066 | * |
1067 | * Sometimes it is undesirable to wait for a folio to be unlocked (eg |
1068 | * when the locks are being taken in the wrong order, or if making |
1069 | * progress through a batch of folios is more important than processing |
1070 | * them in order). Usually folio_lock() is the correct function to call. |
1071 | * |
1072 | * Context: Any context. |
1073 | * Return: Whether the lock was successfully acquired. |
1074 | */ |
1075 | static inline bool folio_trylock(struct folio *folio) |
1076 | { |
1077 | return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0))); |
1078 | } |
1079 | |
1080 | /* |
1081 | * Return true if the page was successfully locked |
1082 | */ |
1083 | static inline bool trylock_page(struct page *page) |
1084 | { |
1085 | return folio_trylock(page_folio(page)); |
1086 | } |
1087 | |
1088 | /** |
1089 | * folio_lock() - Lock this folio. |
1090 | * @folio: The folio to lock. |
1091 | * |
1092 | * The folio lock protects against many things, probably more than it |
1093 | * should. It is primarily held while a folio is being brought uptodate, |
1094 | * either from its backing file or from swap. It is also held while a |
1095 | * folio is being truncated from its address_space, so holding the lock |
1096 | * is sufficient to keep folio->mapping stable. |
1097 | * |
1098 | * The folio lock is also held while write() is modifying the page to |
1099 | * provide POSIX atomicity guarantees (as long as the write does not |
1100 | * cross a page boundary). Other modifications to the data in the folio |
1101 | * do not hold the folio lock and can race with writes, eg DMA and stores |
1102 | * to mapped pages. |
1103 | * |
1104 | * Context: May sleep. If you need to acquire the locks of two or |
1105 | * more folios, they must be in order of ascending index, if they are |
1106 | * in the same address_space. If they are in different address_spaces, |
1107 | * acquire the lock of the folio which belongs to the address_space which |
1108 | * has the lowest address in memory first. |
1109 | */ |
1110 | static inline void folio_lock(struct folio *folio) |
1111 | { |
1112 | might_sleep(); |
1113 | if (!folio_trylock(folio)) |
1114 | __folio_lock(folio); |
1115 | } |
1116 | |
1117 | /** |
1118 | * lock_page() - Lock the folio containing this page. |
1119 | * @page: The page to lock. |
1120 | * |
1121 | * See folio_lock() for a description of what the lock protects. |
1122 | * This is a legacy function and new code should probably use folio_lock() |
1123 | * instead. |
1124 | * |
1125 | * Context: May sleep. Pages in the same folio share a lock, so do not |
1126 | * attempt to lock two pages which share a folio. |
1127 | */ |
1128 | static inline void lock_page(struct page *page) |
1129 | { |
1130 | struct folio *folio; |
1131 | might_sleep(); |
1132 | |
1133 | folio = page_folio(page); |
1134 | if (!folio_trylock(folio)) |
1135 | __folio_lock(folio); |
1136 | } |
1137 | |
1138 | /** |
1139 | * folio_lock_killable() - Lock this folio, interruptible by a fatal signal. |
1140 | * @folio: The folio to lock. |
1141 | * |
1142 | * Attempts to lock the folio, like folio_lock(), except that the sleep |
1143 | * to acquire the lock is interruptible by a fatal signal. |
1144 | * |
1145 | * Context: May sleep; see folio_lock(). |
1146 | * Return: 0 if the lock was acquired; -EINTR if a fatal signal was received. |
1147 | */ |
1148 | static inline int folio_lock_killable(struct folio *folio) |
1149 | { |
1150 | might_sleep(); |
1151 | if (!folio_trylock(folio)) |
1152 | return __folio_lock_killable(folio); |
1153 | return 0; |
1154 | } |
1155 | |
1156 | /* |
1157 | * folio_lock_or_retry - Lock the folio, unless this would block and the |
1158 | * caller indicated that it can handle a retry. |
1159 | * |
1160 | * Return value and mmap_lock implications depend on flags; see |
1161 | * __folio_lock_or_retry(). |
1162 | */ |
1163 | static inline vm_fault_t folio_lock_or_retry(struct folio *folio, |
1164 | struct vm_fault *vmf) |
1165 | { |
1166 | might_sleep(); |
1167 | if (!folio_trylock(folio)) |
1168 | return __folio_lock_or_retry(folio, vmf); |
1169 | return 0; |
1170 | } |
1171 | |
1172 | /* |
1173 | * This is exported only for folio_wait_locked/folio_wait_writeback, etc., |
1174 | * and should not be used directly. |
1175 | */ |
1176 | void folio_wait_bit(struct folio *folio, int bit_nr); |
1177 | int folio_wait_bit_killable(struct folio *folio, int bit_nr); |
1178 | |
1179 | /* |
1180 | * Wait for a folio to be unlocked. |
1181 | * |
1182 | * This must be called with the caller "holding" the folio, |
1183 | * ie with increased folio reference count so that the folio won't |
1184 | * go away during the wait. |
1185 | */ |
1186 | static inline void folio_wait_locked(struct folio *folio) |
1187 | { |
1188 | if (folio_test_locked(folio)) |
1189 | folio_wait_bit(folio, bit_nr: PG_locked); |
1190 | } |
1191 | |
1192 | static inline int folio_wait_locked_killable(struct folio *folio) |
1193 | { |
1194 | if (!folio_test_locked(folio)) |
1195 | return 0; |
1196 | return folio_wait_bit_killable(folio, bit_nr: PG_locked); |
1197 | } |
1198 | |
1199 | void folio_end_read(struct folio *folio, bool success); |
1200 | void wait_on_page_writeback(struct page *page); |
1201 | void folio_wait_writeback(struct folio *folio); |
1202 | int folio_wait_writeback_killable(struct folio *folio); |
1203 | void end_page_writeback(struct page *page); |
1204 | void folio_end_writeback(struct folio *folio); |
1205 | void folio_wait_stable(struct folio *folio); |
1206 | void __folio_mark_dirty(struct folio *folio, struct address_space *, int warn); |
1207 | void folio_account_cleaned(struct folio *folio, struct bdi_writeback *wb); |
1208 | void __folio_cancel_dirty(struct folio *folio); |
1209 | static inline void folio_cancel_dirty(struct folio *folio) |
1210 | { |
1211 | /* Avoid atomic ops, locking, etc. when not actually needed. */ |
1212 | if (folio_test_dirty(folio)) |
1213 | __folio_cancel_dirty(folio); |
1214 | } |
1215 | bool folio_clear_dirty_for_io(struct folio *folio); |
1216 | bool clear_page_dirty_for_io(struct page *page); |
1217 | void folio_invalidate(struct folio *folio, size_t offset, size_t length); |
1218 | bool noop_dirty_folio(struct address_space *mapping, struct folio *folio); |
1219 | |
1220 | #ifdef CONFIG_MIGRATION |
1221 | int filemap_migrate_folio(struct address_space *mapping, struct folio *dst, |
1222 | struct folio *src, enum migrate_mode mode); |
1223 | #else |
1224 | #define filemap_migrate_folio NULL |
1225 | #endif |
1226 | void folio_end_private_2(struct folio *folio); |
1227 | void folio_wait_private_2(struct folio *folio); |
1228 | int folio_wait_private_2_killable(struct folio *folio); |
1229 | |
1230 | /* |
1231 | * Fault in userspace address range. |
1232 | */ |
1233 | size_t fault_in_writeable(char __user *uaddr, size_t size); |
1234 | size_t fault_in_subpage_writeable(char __user *uaddr, size_t size); |
1235 | size_t fault_in_safe_writeable(const char __user *uaddr, size_t size); |
1236 | size_t fault_in_readable(const char __user *uaddr, size_t size); |
1237 | |
1238 | int add_to_page_cache_lru(struct page *page, struct address_space *mapping, |
1239 | pgoff_t index, gfp_t gfp); |
1240 | int filemap_add_folio(struct address_space *mapping, struct folio *folio, |
1241 | pgoff_t index, gfp_t gfp); |
1242 | void filemap_remove_folio(struct folio *folio); |
1243 | void __filemap_remove_folio(struct folio *folio, void *shadow); |
1244 | void replace_page_cache_folio(struct folio *old, struct folio *new); |
1245 | void delete_from_page_cache_batch(struct address_space *mapping, |
1246 | struct folio_batch *fbatch); |
1247 | bool filemap_release_folio(struct folio *folio, gfp_t gfp); |
1248 | loff_t mapping_seek_hole_data(struct address_space *, loff_t start, loff_t end, |
1249 | int whence); |
1250 | |
1251 | /* Must be non-static for BPF error injection */ |
1252 | int __filemap_add_folio(struct address_space *mapping, struct folio *folio, |
1253 | pgoff_t index, gfp_t gfp, void **shadowp); |
1254 | |
1255 | bool filemap_range_has_writeback(struct address_space *mapping, |
1256 | loff_t start_byte, loff_t end_byte); |
1257 | |
1258 | /** |
1259 | * filemap_range_needs_writeback - check if range potentially needs writeback |
1260 | * @mapping: address space within which to check |
1261 | * @start_byte: offset in bytes where the range starts |
1262 | * @end_byte: offset in bytes where the range ends (inclusive) |
1263 | * |
1264 | * Find at least one page in the range supplied, usually used to check if |
1265 | * direct writing in this range will trigger a writeback. Used by O_DIRECT |
1266 | * read/write with IOCB_NOWAIT, to see if the caller needs to do |
1267 | * filemap_write_and_wait_range() before proceeding. |
1268 | * |
1269 | * Return: %true if the caller should do filemap_write_and_wait_range() before |
1270 | * doing O_DIRECT to a page in this range, %false otherwise. |
1271 | */ |
1272 | static inline bool filemap_range_needs_writeback(struct address_space *mapping, |
1273 | loff_t start_byte, |
1274 | loff_t end_byte) |
1275 | { |
1276 | if (!mapping->nrpages) |
1277 | return false; |
1278 | if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && |
1279 | !mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) |
1280 | return false; |
1281 | return filemap_range_has_writeback(mapping, start_byte, end_byte); |
1282 | } |
1283 | |
1284 | /** |
1285 | * struct readahead_control - Describes a readahead request. |
1286 | * |
1287 | * A readahead request is for consecutive pages. Filesystems which |
1288 | * implement the ->readahead method should call readahead_folio() or |
1289 | * __readahead_batch() in a loop and attempt to start reads into each |
1290 | * folio in the request. |
1291 | * |
1292 | * Most of the fields in this struct are private and should be accessed |
1293 | * by the functions below. |
1294 | * |
1295 | * @file: The file, used primarily by network filesystems for authentication. |
1296 | * May be NULL if invoked internally by the filesystem. |
1297 | * @mapping: Readahead this filesystem object. |
1298 | * @ra: File readahead state. May be NULL. |
1299 | */ |
1300 | struct readahead_control { |
1301 | struct file *file; |
1302 | struct address_space *mapping; |
1303 | struct file_ra_state *ra; |
1304 | /* private: use the readahead_* accessors instead */ |
1305 | pgoff_t _index; |
1306 | unsigned int _nr_pages; |
1307 | unsigned int _batch_count; |
1308 | bool dropbehind; |
1309 | bool _workingset; |
1310 | unsigned long _pflags; |
1311 | }; |
1312 | |
1313 | #define DEFINE_READAHEAD(ractl, f, r, m, i) \ |
1314 | struct readahead_control ractl = { \ |
1315 | .file = f, \ |
1316 | .mapping = m, \ |
1317 | .ra = r, \ |
1318 | ._index = i, \ |
1319 | } |
1320 | |
1321 | #define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE) |
1322 | |
1323 | void page_cache_ra_unbounded(struct readahead_control *, |
1324 | unsigned long nr_to_read, unsigned long lookahead_count); |
1325 | void page_cache_sync_ra(struct readahead_control *, unsigned long req_count); |
1326 | void page_cache_async_ra(struct readahead_control *, struct folio *, |
1327 | unsigned long req_count); |
1328 | void readahead_expand(struct readahead_control *ractl, |
1329 | loff_t new_start, size_t new_len); |
1330 | |
1331 | /** |
1332 | * page_cache_sync_readahead - generic file readahead |
1333 | * @mapping: address_space which holds the pagecache and I/O vectors |
1334 | * @ra: file_ra_state which holds the readahead state |
1335 | * @file: Used by the filesystem for authentication. |
1336 | * @index: Index of first page to be read. |
1337 | * @req_count: Total number of pages being read by the caller. |
1338 | * |
1339 | * page_cache_sync_readahead() should be called when a cache miss happened: |
1340 | * it will submit the read. The readahead logic may decide to piggyback more |
1341 | * pages onto the read request if access patterns suggest it will improve |
1342 | * performance. |
1343 | */ |
1344 | static inline |
1345 | void page_cache_sync_readahead(struct address_space *mapping, |
1346 | struct file_ra_state *ra, struct file *file, pgoff_t index, |
1347 | unsigned long req_count) |
1348 | { |
1349 | DEFINE_READAHEAD(ractl, file, ra, mapping, index); |
1350 | page_cache_sync_ra(&ractl, req_count); |
1351 | } |
1352 | |
1353 | /** |
1354 | * page_cache_async_readahead - file readahead for marked pages |
1355 | * @mapping: address_space which holds the pagecache and I/O vectors |
1356 | * @ra: file_ra_state which holds the readahead state |
1357 | * @file: Used by the filesystem for authentication. |
1358 | * @folio: The folio which triggered the readahead call. |
1359 | * @req_count: Total number of pages being read by the caller. |
1360 | * |
1361 | * page_cache_async_readahead() should be called when a page is used which |
1362 | * is marked as PageReadahead; this is a marker to suggest that the application |
1363 | * has used up enough of the readahead window that we should start pulling in |
1364 | * more pages. |
1365 | */ |
1366 | static inline |
1367 | void page_cache_async_readahead(struct address_space *mapping, |
1368 | struct file_ra_state *ra, struct file *file, |
1369 | struct folio *folio, unsigned long req_count) |
1370 | { |
1371 | DEFINE_READAHEAD(ractl, file, ra, mapping, folio->index); |
1372 | page_cache_async_ra(&ractl, folio, req_count); |
1373 | } |
1374 | |
1375 | static inline struct folio *__readahead_folio(struct readahead_control *ractl) |
1376 | { |
1377 | struct folio *folio; |
1378 | |
1379 | BUG_ON(ractl->_batch_count > ractl->_nr_pages); |
1380 | ractl->_nr_pages -= ractl->_batch_count; |
1381 | ractl->_index += ractl->_batch_count; |
1382 | |
1383 | if (!ractl->_nr_pages) { |
1384 | ractl->_batch_count = 0; |
1385 | return NULL; |
1386 | } |
1387 | |
1388 | folio = xa_load(&ractl->mapping->i_pages, index: ractl->_index); |
1389 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
1390 | ractl->_batch_count = folio_nr_pages(folio); |
1391 | |
1392 | return folio; |
1393 | } |
1394 | |
1395 | /** |
1396 | * readahead_folio - Get the next folio to read. |
1397 | * @ractl: The current readahead request. |
1398 | * |
1399 | * Context: The folio is locked. The caller should unlock the folio once |
1400 | * all I/O to that folio has completed. |
1401 | * Return: A pointer to the next folio, or %NULL if we are done. |
1402 | */ |
1403 | static inline struct folio *readahead_folio(struct readahead_control *ractl) |
1404 | { |
1405 | struct folio *folio = __readahead_folio(ractl); |
1406 | |
1407 | if (folio) |
1408 | folio_put(folio); |
1409 | return folio; |
1410 | } |
1411 | |
1412 | static inline unsigned int __readahead_batch(struct readahead_control *rac, |
1413 | struct page **array, unsigned int array_sz) |
1414 | { |
1415 | unsigned int i = 0; |
1416 | XA_STATE(xas, &rac->mapping->i_pages, 0); |
1417 | struct folio *folio; |
1418 | |
1419 | BUG_ON(rac->_batch_count > rac->_nr_pages); |
1420 | rac->_nr_pages -= rac->_batch_count; |
1421 | rac->_index += rac->_batch_count; |
1422 | rac->_batch_count = 0; |
1423 | |
1424 | xas_set(xas: &xas, index: rac->_index); |
1425 | rcu_read_lock(); |
1426 | xas_for_each(&xas, folio, rac->_index + rac->_nr_pages - 1) { |
1427 | if (xas_retry(xas: &xas, entry: folio)) |
1428 | continue; |
1429 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
1430 | array[i++] = folio_page(folio, 0); |
1431 | rac->_batch_count += folio_nr_pages(folio); |
1432 | if (i == array_sz) |
1433 | break; |
1434 | } |
1435 | rcu_read_unlock(); |
1436 | |
1437 | return i; |
1438 | } |
1439 | |
1440 | /** |
1441 | * readahead_pos - The byte offset into the file of this readahead request. |
1442 | * @rac: The readahead request. |
1443 | */ |
1444 | static inline loff_t readahead_pos(struct readahead_control *rac) |
1445 | { |
1446 | return (loff_t)rac->_index * PAGE_SIZE; |
1447 | } |
1448 | |
1449 | /** |
1450 | * readahead_length - The number of bytes in this readahead request. |
1451 | * @rac: The readahead request. |
1452 | */ |
1453 | static inline size_t readahead_length(struct readahead_control *rac) |
1454 | { |
1455 | return rac->_nr_pages * PAGE_SIZE; |
1456 | } |
1457 | |
1458 | /** |
1459 | * readahead_index - The index of the first page in this readahead request. |
1460 | * @rac: The readahead request. |
1461 | */ |
1462 | static inline pgoff_t readahead_index(struct readahead_control *rac) |
1463 | { |
1464 | return rac->_index; |
1465 | } |
1466 | |
1467 | /** |
1468 | * readahead_count - The number of pages in this readahead request. |
1469 | * @rac: The readahead request. |
1470 | */ |
1471 | static inline unsigned int readahead_count(struct readahead_control *rac) |
1472 | { |
1473 | return rac->_nr_pages; |
1474 | } |
1475 | |
1476 | /** |
1477 | * readahead_batch_length - The number of bytes in the current batch. |
1478 | * @rac: The readahead request. |
1479 | */ |
1480 | static inline size_t readahead_batch_length(struct readahead_control *rac) |
1481 | { |
1482 | return rac->_batch_count * PAGE_SIZE; |
1483 | } |
1484 | |
1485 | static inline unsigned long dir_pages(struct inode *inode) |
1486 | { |
1487 | return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >> |
1488 | PAGE_SHIFT; |
1489 | } |
1490 | |
1491 | /** |
1492 | * folio_mkwrite_check_truncate - check if folio was truncated |
1493 | * @folio: the folio to check |
1494 | * @inode: the inode to check the folio against |
1495 | * |
1496 | * Return: the number of bytes in the folio up to EOF, |
1497 | * or -EFAULT if the folio was truncated. |
1498 | */ |
1499 | static inline ssize_t folio_mkwrite_check_truncate(struct folio *folio, |
1500 | struct inode *inode) |
1501 | { |
1502 | loff_t size = i_size_read(inode); |
1503 | pgoff_t index = size >> PAGE_SHIFT; |
1504 | size_t offset = offset_in_folio(folio, size); |
1505 | |
1506 | if (!folio->mapping) |
1507 | return -EFAULT; |
1508 | |
1509 | /* folio is wholly inside EOF */ |
1510 | if (folio_next_index(folio) - 1 < index) |
1511 | return folio_size(folio); |
1512 | /* folio is wholly past EOF */ |
1513 | if (folio->index > index || !offset) |
1514 | return -EFAULT; |
1515 | /* folio is partially inside EOF */ |
1516 | return offset; |
1517 | } |
1518 | |
1519 | /** |
1520 | * i_blocks_per_folio - How many blocks fit in this folio. |
1521 | * @inode: The inode which contains the blocks. |
1522 | * @folio: The folio. |
1523 | * |
1524 | * If the block size is larger than the size of this folio, return zero. |
1525 | * |
1526 | * Context: The caller should hold a refcount on the folio to prevent it |
1527 | * from being split. |
1528 | * Return: The number of filesystem blocks covered by this folio. |
1529 | */ |
1530 | static inline |
1531 | unsigned int i_blocks_per_folio(struct inode *inode, struct folio *folio) |
1532 | { |
1533 | return folio_size(folio) >> inode->i_blkbits; |
1534 | } |
1535 | #endif /* _LINUX_PAGEMAP_H */ |
1536 | |