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