1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_PAGEMAP_H
3 #define _LINUX_PAGEMAP_H
6 * Copyright 1995 Linus Torvalds
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>
21 static inline bool mapping_empty(struct address_space *mapping)
23 return xa_empty(&mapping->i_pages);
27 * mapping_shrinkable - test if page cache state allows inode reclaim
28 * @mapping: the page cache mapping
30 * This checks the mapping's cache state for the pupose of inode
31 * reclaim and LRU management.
33 * The caller is expected to hold the i_lock, but is not required to
34 * hold the i_pages lock, which usually protects cache state. That's
35 * because the i_lock and the list_lru lock that protect the inode and
36 * its LRU state don't nest inside the irq-safe i_pages lock.
38 * Cache deletions are performed under the i_lock, which ensures that
39 * when an inode goes empty, it will reliably get queued on the LRU.
41 * Cache additions do not acquire the i_lock and may race with this
42 * check, in which case we'll report the inode as shrinkable when it
43 * has cache pages. This is okay: the shrinker also checks the
44 * refcount and the referenced bit, which will be elevated or set in
45 * the process of adding new cache pages to an inode.
47 static inline bool mapping_shrinkable(struct address_space *mapping)
52 * On highmem systems, there could be lowmem pressure from the
53 * inodes before there is highmem pressure from the page
54 * cache. Make inodes shrinkable regardless of cache state.
56 if (IS_ENABLED(CONFIG_HIGHMEM))
59 /* Cache completely empty? Shrink away. */
60 head = rcu_access_pointer(mapping->i_pages.xa_head);
65 * The xarray stores single offset-0 entries directly in the
66 * head pointer, which allows non-resident page cache entries
67 * to escape the shadow shrinker's list of xarray nodes. The
68 * inode shrinker needs to pick them up under memory pressure.
70 if (!xa_is_node(head) && xa_is_value(head))
77 * Bits in mapping->flags.
80 AS_EIO = 0, /* IO error on async write */
81 AS_ENOSPC = 1, /* ENOSPC on async write */
82 AS_MM_ALL_LOCKS = 2, /* under mm_take_all_locks() */
83 AS_UNEVICTABLE = 3, /* e.g., ramdisk, SHM_LOCK */
84 AS_EXITING = 4, /* final truncate in progress */
85 /* writeback related tags are not used */
86 AS_NO_WRITEBACK_TAGS = 5,
87 AS_LARGE_FOLIO_SUPPORT = 6,
91 * mapping_set_error - record a writeback error in the address_space
92 * @mapping: the mapping in which an error should be set
93 * @error: the error to set in the mapping
95 * When writeback fails in some way, we must record that error so that
96 * userspace can be informed when fsync and the like are called. We endeavor
97 * to report errors on any file that was open at the time of the error. Some
98 * internal callers also need to know when writeback errors have occurred.
100 * When a writeback error occurs, most filesystems will want to call
101 * mapping_set_error to record the error in the mapping so that it can be
102 * reported when the application calls fsync(2).
104 static inline void mapping_set_error(struct address_space *mapping, int error)
109 /* Record in wb_err for checkers using errseq_t based tracking */
110 __filemap_set_wb_err(mapping, error);
112 /* Record it in superblock */
114 errseq_set(&mapping->host->i_sb->s_wb_err, error);
116 /* Record it in flags for now, for legacy callers */
117 if (error == -ENOSPC)
118 set_bit(AS_ENOSPC, &mapping->flags);
120 set_bit(AS_EIO, &mapping->flags);
123 static inline void mapping_set_unevictable(struct address_space *mapping)
125 set_bit(AS_UNEVICTABLE, &mapping->flags);
128 static inline void mapping_clear_unevictable(struct address_space *mapping)
130 clear_bit(AS_UNEVICTABLE, &mapping->flags);
133 static inline bool mapping_unevictable(struct address_space *mapping)
135 return mapping && test_bit(AS_UNEVICTABLE, &mapping->flags);
138 static inline void mapping_set_exiting(struct address_space *mapping)
140 set_bit(AS_EXITING, &mapping->flags);
143 static inline int mapping_exiting(struct address_space *mapping)
145 return test_bit(AS_EXITING, &mapping->flags);
148 static inline void mapping_set_no_writeback_tags(struct address_space *mapping)
150 set_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
153 static inline int mapping_use_writeback_tags(struct address_space *mapping)
155 return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
158 static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
160 return mapping->gfp_mask;
163 /* Restricts the given gfp_mask to what the mapping allows. */
164 static inline gfp_t mapping_gfp_constraint(struct address_space *mapping,
167 return mapping_gfp_mask(mapping) & gfp_mask;
171 * This is non-atomic. Only to be used before the mapping is activated.
172 * Probably needs a barrier...
174 static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
180 * mapping_set_large_folios() - Indicate the file supports large folios.
181 * @mapping: The file.
183 * The filesystem should call this function in its inode constructor to
184 * indicate that the VFS can use large folios to cache the contents of
187 * Context: This should not be called while the inode is active as it
190 static inline void mapping_set_large_folios(struct address_space *mapping)
192 __set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
195 static inline bool mapping_large_folio_support(struct address_space *mapping)
197 return test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
200 static inline int filemap_nr_thps(struct address_space *mapping)
202 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
203 return atomic_read(&mapping->nr_thps);
209 static inline void filemap_nr_thps_inc(struct address_space *mapping)
211 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
212 if (!mapping_large_folio_support(mapping))
213 atomic_inc(&mapping->nr_thps);
219 static inline void filemap_nr_thps_dec(struct address_space *mapping)
221 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
222 if (!mapping_large_folio_support(mapping))
223 atomic_dec(&mapping->nr_thps);
229 void release_pages(struct page **pages, int nr);
231 struct address_space *page_mapping(struct page *);
232 struct address_space *folio_mapping(struct folio *);
233 struct address_space *swapcache_mapping(struct folio *);
236 * folio_file_mapping - Find the mapping this folio belongs to.
239 * For folios which are in the page cache, return the mapping that this
240 * page belongs to. Folios in the swap cache return the mapping of the
241 * swap file or swap device where the data is stored. This is different
242 * from the mapping returned by folio_mapping(). The only reason to
243 * use it is if, like NFS, you return 0 from ->activate_swapfile.
245 * Do not call this for folios which aren't in the page cache or swap cache.
247 static inline struct address_space *folio_file_mapping(struct folio *folio)
249 if (unlikely(folio_test_swapcache(folio)))
250 return swapcache_mapping(folio);
252 return folio->mapping;
255 static inline struct address_space *page_file_mapping(struct page *page)
257 return folio_file_mapping(page_folio(page));
261 * For file cache pages, return the address_space, otherwise return NULL
263 static inline struct address_space *page_mapping_file(struct page *page)
265 struct folio *folio = page_folio(page);
267 if (unlikely(folio_test_swapcache(folio)))
269 return folio_mapping(folio);
273 * folio_inode - Get the host inode for this folio.
276 * For folios which are in the page cache, return the inode that this folio
279 * Do not call this for folios which aren't in the page cache.
281 static inline struct inode *folio_inode(struct folio *folio)
283 return folio->mapping->host;
286 static inline bool page_cache_add_speculative(struct page *page, int count)
288 return folio_ref_try_add_rcu((struct folio *)page, count);
291 static inline bool page_cache_get_speculative(struct page *page)
293 return page_cache_add_speculative(page, 1);
297 * folio_attach_private - Attach private data to a folio.
298 * @folio: Folio to attach data to.
299 * @data: Data to attach to folio.
301 * Attaching private data to a folio increments the page's reference count.
302 * The data must be detached before the folio will be freed.
304 static inline void folio_attach_private(struct folio *folio, void *data)
307 folio->private = data;
308 folio_set_private(folio);
312 * folio_change_private - Change private data on a folio.
313 * @folio: Folio to change the data on.
314 * @data: Data to set on the folio.
316 * Change the private data attached to a folio and return the old
317 * data. The page must previously have had data attached and the data
318 * must be detached before the folio will be freed.
320 * Return: Data that was previously attached to the folio.
322 static inline void *folio_change_private(struct folio *folio, void *data)
324 void *old = folio_get_private(folio);
326 folio->private = data;
331 * folio_detach_private - Detach private data from a folio.
332 * @folio: Folio to detach data from.
334 * Removes the data that was previously attached to the folio and decrements
335 * the refcount on the page.
337 * Return: Data that was attached to the folio.
339 static inline void *folio_detach_private(struct folio *folio)
341 void *data = folio_get_private(folio);
343 if (!folio_test_private(folio))
345 folio_clear_private(folio);
346 folio->private = NULL;
352 static inline void attach_page_private(struct page *page, void *data)
354 folio_attach_private(page_folio(page), data);
357 static inline void *detach_page_private(struct page *page)
359 return folio_detach_private(page_folio(page));
363 struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order);
365 static inline struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order)
367 return folio_alloc(gfp, order);
371 static inline struct page *__page_cache_alloc(gfp_t gfp)
373 return &filemap_alloc_folio(gfp, 0)->page;
376 static inline struct page *page_cache_alloc(struct address_space *x)
378 return __page_cache_alloc(mapping_gfp_mask(x));
381 static inline gfp_t readahead_gfp_mask(struct address_space *x)
383 return mapping_gfp_mask(x) | __GFP_NORETRY | __GFP_NOWARN;
386 typedef int filler_t(void *, struct page *);
388 pgoff_t page_cache_next_miss(struct address_space *mapping,
389 pgoff_t index, unsigned long max_scan);
390 pgoff_t page_cache_prev_miss(struct address_space *mapping,
391 pgoff_t index, unsigned long max_scan);
393 #define FGP_ACCESSED 0x00000001
394 #define FGP_LOCK 0x00000002
395 #define FGP_CREAT 0x00000004
396 #define FGP_WRITE 0x00000008
397 #define FGP_NOFS 0x00000010
398 #define FGP_NOWAIT 0x00000020
399 #define FGP_FOR_MMAP 0x00000040
400 #define FGP_HEAD 0x00000080
401 #define FGP_ENTRY 0x00000100
402 #define FGP_STABLE 0x00000200
404 struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
405 int fgp_flags, gfp_t gfp);
406 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
407 int fgp_flags, gfp_t gfp);
410 * filemap_get_folio - Find and get a folio.
411 * @mapping: The address_space to search.
412 * @index: The page index.
414 * Looks up the page cache entry at @mapping & @index. If a folio is
415 * present, it is returned with an increased refcount.
417 * Otherwise, %NULL is returned.
419 static inline struct folio *filemap_get_folio(struct address_space *mapping,
422 return __filemap_get_folio(mapping, index, 0, 0);
426 * find_get_page - find and get a page reference
427 * @mapping: the address_space to search
428 * @offset: the page index
430 * Looks up the page cache slot at @mapping & @offset. If there is a
431 * page cache page, it is returned with an increased refcount.
433 * Otherwise, %NULL is returned.
435 static inline struct page *find_get_page(struct address_space *mapping,
438 return pagecache_get_page(mapping, offset, 0, 0);
441 static inline struct page *find_get_page_flags(struct address_space *mapping,
442 pgoff_t offset, int fgp_flags)
444 return pagecache_get_page(mapping, offset, fgp_flags, 0);
448 * find_lock_page - locate, pin and lock a pagecache page
449 * @mapping: the address_space to search
450 * @index: the page index
452 * Looks up the page cache entry at @mapping & @index. If there is a
453 * page cache page, it is returned locked and with an increased
456 * Context: May sleep.
457 * Return: A struct page or %NULL if there is no page in the cache for this
460 static inline struct page *find_lock_page(struct address_space *mapping,
463 return pagecache_get_page(mapping, index, FGP_LOCK, 0);
467 * find_or_create_page - locate or add a pagecache page
468 * @mapping: the page's address_space
469 * @index: the page's index into the mapping
470 * @gfp_mask: page allocation mode
472 * Looks up the page cache slot at @mapping & @offset. If there is a
473 * page cache page, it is returned locked and with an increased
476 * If the page is not present, a new page is allocated using @gfp_mask
477 * and added to the page cache and the VM's LRU list. The page is
478 * returned locked and with an increased refcount.
480 * On memory exhaustion, %NULL is returned.
482 * find_or_create_page() may sleep, even if @gfp_flags specifies an
485 static inline struct page *find_or_create_page(struct address_space *mapping,
486 pgoff_t index, gfp_t gfp_mask)
488 return pagecache_get_page(mapping, index,
489 FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
494 * grab_cache_page_nowait - returns locked page at given index in given cache
495 * @mapping: target address_space
496 * @index: the page index
498 * Same as grab_cache_page(), but do not wait if the page is unavailable.
499 * This is intended for speculative data generators, where the data can
500 * be regenerated if the page couldn't be grabbed. This routine should
501 * be safe to call while holding the lock for another page.
503 * Clear __GFP_FS when allocating the page to avoid recursion into the fs
504 * and deadlock against the caller's locked page.
506 static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
509 return pagecache_get_page(mapping, index,
510 FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
511 mapping_gfp_mask(mapping));
514 #define swapcache_index(folio) __page_file_index(&(folio)->page)
517 * folio_index - File index of a folio.
520 * For a folio which is either in the page cache or the swap cache,
521 * return its index within the address_space it belongs to. If you know
522 * the page is definitely in the page cache, you can look at the folio's
525 * Return: The index (offset in units of pages) of a folio in its file.
527 static inline pgoff_t folio_index(struct folio *folio)
529 if (unlikely(folio_test_swapcache(folio)))
530 return swapcache_index(folio);
535 * folio_next_index - Get the index of the next folio.
536 * @folio: The current folio.
538 * Return: The index of the folio which follows this folio in the file.
540 static inline pgoff_t folio_next_index(struct folio *folio)
542 return folio->index + folio_nr_pages(folio);
546 * folio_file_page - The page for a particular index.
547 * @folio: The folio which contains this index.
548 * @index: The index we want to look up.
550 * Sometimes after looking up a folio in the page cache, we need to
551 * obtain the specific page for an index (eg a page fault).
553 * Return: The page containing the file data for this index.
555 static inline struct page *folio_file_page(struct folio *folio, pgoff_t index)
557 /* HugeTLBfs indexes the page cache in units of hpage_size */
558 if (folio_test_hugetlb(folio))
560 return folio_page(folio, index & (folio_nr_pages(folio) - 1));
564 * folio_contains - Does this folio contain this index?
566 * @index: The page index within the file.
568 * Context: The caller should have the page locked in order to prevent
569 * (eg) shmem from moving the page between the page cache and swap cache
570 * and changing its index in the middle of the operation.
571 * Return: true or false.
573 static inline bool folio_contains(struct folio *folio, pgoff_t index)
575 /* HugeTLBfs indexes the page cache in units of hpage_size */
576 if (folio_test_hugetlb(folio))
577 return folio->index == index;
578 return index - folio_index(folio) < folio_nr_pages(folio);
582 * Given the page we found in the page cache, return the page corresponding
583 * to this index in the file
585 static inline struct page *find_subpage(struct page *head, pgoff_t index)
587 /* HugeTLBfs wants the head page regardless */
591 return head + (index & (thp_nr_pages(head) - 1));
594 unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
595 pgoff_t end, unsigned int nr_pages,
596 struct page **pages);
597 static inline unsigned find_get_pages(struct address_space *mapping,
598 pgoff_t *start, unsigned int nr_pages,
601 return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages,
604 unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
605 unsigned int nr_pages, struct page **pages);
606 unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
607 pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
608 struct page **pages);
609 static inline unsigned find_get_pages_tag(struct address_space *mapping,
610 pgoff_t *index, xa_mark_t tag, unsigned int nr_pages,
613 return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag,
617 struct page *grab_cache_page_write_begin(struct address_space *mapping,
618 pgoff_t index, unsigned flags);
621 * Returns locked page at given index in given cache, creating it if needed.
623 static inline struct page *grab_cache_page(struct address_space *mapping,
626 return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
629 struct folio *read_cache_folio(struct address_space *, pgoff_t index,
630 filler_t *filler, void *data);
631 struct page *read_cache_page(struct address_space *, pgoff_t index,
632 filler_t *filler, void *data);
633 extern struct page * read_cache_page_gfp(struct address_space *mapping,
634 pgoff_t index, gfp_t gfp_mask);
635 extern int read_cache_pages(struct address_space *mapping,
636 struct list_head *pages, filler_t *filler, void *data);
638 static inline struct page *read_mapping_page(struct address_space *mapping,
639 pgoff_t index, void *data)
641 return read_cache_page(mapping, index, NULL, data);
644 static inline struct folio *read_mapping_folio(struct address_space *mapping,
645 pgoff_t index, void *data)
647 return read_cache_folio(mapping, index, NULL, data);
651 * Get index of the page within radix-tree (but not for hugetlb pages).
652 * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
654 static inline pgoff_t page_to_index(struct page *page)
658 if (likely(!PageTransTail(page)))
661 head = compound_head(page);
663 * We don't initialize ->index for tail pages: calculate based on
666 return head->index + page - head;
669 extern pgoff_t hugetlb_basepage_index(struct page *page);
672 * Get the offset in PAGE_SIZE (even for hugetlb pages).
673 * (TODO: hugetlb pages should have ->index in PAGE_SIZE)
675 static inline pgoff_t page_to_pgoff(struct page *page)
677 if (unlikely(PageHuge(page)))
678 return hugetlb_basepage_index(page);
679 return page_to_index(page);
683 * Return byte-offset into filesystem object for page.
685 static inline loff_t page_offset(struct page *page)
687 return ((loff_t)page->index) << PAGE_SHIFT;
690 static inline loff_t page_file_offset(struct page *page)
692 return ((loff_t)page_index(page)) << PAGE_SHIFT;
696 * folio_pos - Returns the byte position of this folio in its file.
699 static inline loff_t folio_pos(struct folio *folio)
701 return page_offset(&folio->page);
705 * folio_file_pos - Returns the byte position of this folio in its file.
708 * This differs from folio_pos() for folios which belong to a swap file.
709 * NFS is the only filesystem today which needs to use folio_file_pos().
711 static inline loff_t folio_file_pos(struct folio *folio)
713 return page_file_offset(&folio->page);
716 extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
717 unsigned long address);
719 static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
720 unsigned long address)
723 if (unlikely(is_vm_hugetlb_page(vma)))
724 return linear_hugepage_index(vma, address);
725 pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
726 pgoff += vma->vm_pgoff;
730 struct wait_page_key {
736 struct wait_page_queue {
739 wait_queue_entry_t wait;
742 static inline bool wake_page_match(struct wait_page_queue *wait_page,
743 struct wait_page_key *key)
745 if (wait_page->folio != key->folio)
749 if (wait_page->bit_nr != key->bit_nr)
755 void __folio_lock(struct folio *folio);
756 int __folio_lock_killable(struct folio *folio);
757 bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
759 void unlock_page(struct page *page);
760 void folio_unlock(struct folio *folio);
762 static inline bool folio_trylock(struct folio *folio)
764 return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0)));
768 * Return true if the page was successfully locked
770 static inline int trylock_page(struct page *page)
772 return folio_trylock(page_folio(page));
775 static inline void folio_lock(struct folio *folio)
778 if (!folio_trylock(folio))
783 * lock_page may only be called if we have the page's inode pinned.
785 static inline void lock_page(struct page *page)
790 folio = page_folio(page);
791 if (!folio_trylock(folio))
795 static inline int folio_lock_killable(struct folio *folio)
798 if (!folio_trylock(folio))
799 return __folio_lock_killable(folio);
804 * lock_page_killable is like lock_page but can be interrupted by fatal
805 * signals. It returns 0 if it locked the page and -EINTR if it was
806 * killed while waiting.
808 static inline int lock_page_killable(struct page *page)
810 return folio_lock_killable(page_folio(page));
814 * lock_page_or_retry - Lock the page, unless this would block and the
815 * caller indicated that it can handle a retry.
817 * Return value and mmap_lock implications depend on flags; see
818 * __folio_lock_or_retry().
820 static inline bool lock_page_or_retry(struct page *page, struct mm_struct *mm,
826 folio = page_folio(page);
827 return folio_trylock(folio) || __folio_lock_or_retry(folio, mm, flags);
831 * This is exported only for folio_wait_locked/folio_wait_writeback, etc.,
832 * and should not be used directly.
834 void folio_wait_bit(struct folio *folio, int bit_nr);
835 int folio_wait_bit_killable(struct folio *folio, int bit_nr);
838 * Wait for a folio to be unlocked.
840 * This must be called with the caller "holding" the folio,
841 * ie with increased "page->count" so that the folio won't
842 * go away during the wait..
844 static inline void folio_wait_locked(struct folio *folio)
846 if (folio_test_locked(folio))
847 folio_wait_bit(folio, PG_locked);
850 static inline int folio_wait_locked_killable(struct folio *folio)
852 if (!folio_test_locked(folio))
854 return folio_wait_bit_killable(folio, PG_locked);
857 static inline void wait_on_page_locked(struct page *page)
859 folio_wait_locked(page_folio(page));
862 static inline int wait_on_page_locked_killable(struct page *page)
864 return folio_wait_locked_killable(page_folio(page));
867 int folio_put_wait_locked(struct folio *folio, int state);
868 void wait_on_page_writeback(struct page *page);
869 void folio_wait_writeback(struct folio *folio);
870 int folio_wait_writeback_killable(struct folio *folio);
871 void end_page_writeback(struct page *page);
872 void folio_end_writeback(struct folio *folio);
873 void wait_for_stable_page(struct page *page);
874 void folio_wait_stable(struct folio *folio);
875 void __folio_mark_dirty(struct folio *folio, struct address_space *, int warn);
876 static inline void __set_page_dirty(struct page *page,
877 struct address_space *mapping, int warn)
879 __folio_mark_dirty(page_folio(page), mapping, warn);
881 void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
882 struct bdi_writeback *wb);
883 void __folio_cancel_dirty(struct folio *folio);
884 static inline void folio_cancel_dirty(struct folio *folio)
886 /* Avoid atomic ops, locking, etc. when not actually needed. */
887 if (folio_test_dirty(folio))
888 __folio_cancel_dirty(folio);
890 static inline void cancel_dirty_page(struct page *page)
892 folio_cancel_dirty(page_folio(page));
894 bool folio_clear_dirty_for_io(struct folio *folio);
895 bool clear_page_dirty_for_io(struct page *page);
896 int __must_check folio_write_one(struct folio *folio);
897 static inline int __must_check write_one_page(struct page *page)
899 return folio_write_one(page_folio(page));
902 int __set_page_dirty_nobuffers(struct page *page);
903 int __set_page_dirty_no_writeback(struct page *page);
905 void page_endio(struct page *page, bool is_write, int err);
907 void folio_end_private_2(struct folio *folio);
908 void folio_wait_private_2(struct folio *folio);
909 int folio_wait_private_2_killable(struct folio *folio);
912 * Add an arbitrary waiter to a page's wait queue
914 void folio_add_wait_queue(struct folio *folio, wait_queue_entry_t *waiter);
917 * Fault in userspace address range.
919 size_t fault_in_writeable(char __user *uaddr, size_t size);
920 size_t fault_in_safe_writeable(const char __user *uaddr, size_t size);
921 size_t fault_in_readable(const char __user *uaddr, size_t size);
923 int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
924 pgoff_t index, gfp_t gfp);
925 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
926 pgoff_t index, gfp_t gfp);
927 int filemap_add_folio(struct address_space *mapping, struct folio *folio,
928 pgoff_t index, gfp_t gfp);
929 void filemap_remove_folio(struct folio *folio);
930 void delete_from_page_cache(struct page *page);
931 void __filemap_remove_folio(struct folio *folio, void *shadow);
932 static inline void __delete_from_page_cache(struct page *page, void *shadow)
934 __filemap_remove_folio(page_folio(page), shadow);
936 void replace_page_cache_page(struct page *old, struct page *new);
937 void delete_from_page_cache_batch(struct address_space *mapping,
938 struct folio_batch *fbatch);
939 int try_to_release_page(struct page *page, gfp_t gfp);
940 bool filemap_release_folio(struct folio *folio, gfp_t gfp);
941 loff_t mapping_seek_hole_data(struct address_space *, loff_t start, loff_t end,
945 * Like add_to_page_cache_locked, but used to add newly allocated pages:
946 * the page is new, so we can just run __SetPageLocked() against it.
948 static inline int add_to_page_cache(struct page *page,
949 struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
953 __SetPageLocked(page);
954 error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
956 __ClearPageLocked(page);
960 /* Must be non-static for BPF error injection */
961 int __filemap_add_folio(struct address_space *mapping, struct folio *folio,
962 pgoff_t index, gfp_t gfp, void **shadowp);
964 bool filemap_range_has_writeback(struct address_space *mapping,
965 loff_t start_byte, loff_t end_byte);
968 * filemap_range_needs_writeback - check if range potentially needs writeback
969 * @mapping: address space within which to check
970 * @start_byte: offset in bytes where the range starts
971 * @end_byte: offset in bytes where the range ends (inclusive)
973 * Find at least one page in the range supplied, usually used to check if
974 * direct writing in this range will trigger a writeback. Used by O_DIRECT
975 * read/write with IOCB_NOWAIT, to see if the caller needs to do
976 * filemap_write_and_wait_range() before proceeding.
978 * Return: %true if the caller should do filemap_write_and_wait_range() before
979 * doing O_DIRECT to a page in this range, %false otherwise.
981 static inline bool filemap_range_needs_writeback(struct address_space *mapping,
985 if (!mapping->nrpages)
987 if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
988 !mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
990 return filemap_range_has_writeback(mapping, start_byte, end_byte);
994 * struct readahead_control - Describes a readahead request.
996 * A readahead request is for consecutive pages. Filesystems which
997 * implement the ->readahead method should call readahead_page() or
998 * readahead_page_batch() in a loop and attempt to start I/O against
999 * each page in the request.
1001 * Most of the fields in this struct are private and should be accessed
1002 * by the functions below.
1004 * @file: The file, used primarily by network filesystems for authentication.
1005 * May be NULL if invoked internally by the filesystem.
1006 * @mapping: Readahead this filesystem object.
1007 * @ra: File readahead state. May be NULL.
1009 struct readahead_control {
1011 struct address_space *mapping;
1012 struct file_ra_state *ra;
1013 /* private: use the readahead_* accessors instead */
1015 unsigned int _nr_pages;
1016 unsigned int _batch_count;
1019 #define DEFINE_READAHEAD(ractl, f, r, m, i) \
1020 struct readahead_control ractl = { \
1027 #define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE)
1029 void page_cache_ra_unbounded(struct readahead_control *,
1030 unsigned long nr_to_read, unsigned long lookahead_count);
1031 void page_cache_sync_ra(struct readahead_control *, unsigned long req_count);
1032 void page_cache_async_ra(struct readahead_control *, struct folio *,
1033 unsigned long req_count);
1034 void readahead_expand(struct readahead_control *ractl,
1035 loff_t new_start, size_t new_len);
1038 * page_cache_sync_readahead - generic file readahead
1039 * @mapping: address_space which holds the pagecache and I/O vectors
1040 * @ra: file_ra_state which holds the readahead state
1041 * @file: Used by the filesystem for authentication.
1042 * @index: Index of first page to be read.
1043 * @req_count: Total number of pages being read by the caller.
1045 * page_cache_sync_readahead() should be called when a cache miss happened:
1046 * it will submit the read. The readahead logic may decide to piggyback more
1047 * pages onto the read request if access patterns suggest it will improve
1051 void page_cache_sync_readahead(struct address_space *mapping,
1052 struct file_ra_state *ra, struct file *file, pgoff_t index,
1053 unsigned long req_count)
1055 DEFINE_READAHEAD(ractl, file, ra, mapping, index);
1056 page_cache_sync_ra(&ractl, req_count);
1060 * page_cache_async_readahead - file readahead for marked pages
1061 * @mapping: address_space which holds the pagecache and I/O vectors
1062 * @ra: file_ra_state which holds the readahead state
1063 * @file: Used by the filesystem for authentication.
1064 * @page: The page at @index which triggered the readahead call.
1065 * @index: Index of first page to be read.
1066 * @req_count: Total number of pages being read by the caller.
1068 * page_cache_async_readahead() should be called when a page is used which
1069 * is marked as PageReadahead; this is a marker to suggest that the application
1070 * has used up enough of the readahead window that we should start pulling in
1074 void page_cache_async_readahead(struct address_space *mapping,
1075 struct file_ra_state *ra, struct file *file,
1076 struct page *page, pgoff_t index, unsigned long req_count)
1078 DEFINE_READAHEAD(ractl, file, ra, mapping, index);
1079 page_cache_async_ra(&ractl, page_folio(page), req_count);
1082 static inline struct folio *__readahead_folio(struct readahead_control *ractl)
1084 struct folio *folio;
1086 BUG_ON(ractl->_batch_count > ractl->_nr_pages);
1087 ractl->_nr_pages -= ractl->_batch_count;
1088 ractl->_index += ractl->_batch_count;
1090 if (!ractl->_nr_pages) {
1091 ractl->_batch_count = 0;
1095 folio = xa_load(&ractl->mapping->i_pages, ractl->_index);
1096 VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
1097 ractl->_batch_count = folio_nr_pages(folio);
1103 * readahead_page - Get the next page to read.
1104 * @ractl: The current readahead request.
1106 * Context: The page is locked and has an elevated refcount. The caller
1107 * should decreases the refcount once the page has been submitted for I/O
1108 * and unlock the page once all I/O to that page has completed.
1109 * Return: A pointer to the next page, or %NULL if we are done.
1111 static inline struct page *readahead_page(struct readahead_control *ractl)
1113 struct folio *folio = __readahead_folio(ractl);
1115 return &folio->page;
1119 * readahead_folio - Get the next folio to read.
1120 * @ractl: The current readahead request.
1122 * Context: The folio is locked. The caller should unlock the folio once
1123 * all I/O to that folio has completed.
1124 * Return: A pointer to the next folio, or %NULL if we are done.
1126 static inline struct folio *readahead_folio(struct readahead_control *ractl)
1128 struct folio *folio = __readahead_folio(ractl);
1135 static inline unsigned int __readahead_batch(struct readahead_control *rac,
1136 struct page **array, unsigned int array_sz)
1139 XA_STATE(xas, &rac->mapping->i_pages, 0);
1142 BUG_ON(rac->_batch_count > rac->_nr_pages);
1143 rac->_nr_pages -= rac->_batch_count;
1144 rac->_index += rac->_batch_count;
1145 rac->_batch_count = 0;
1147 xas_set(&xas, rac->_index);
1149 xas_for_each(&xas, page, rac->_index + rac->_nr_pages - 1) {
1150 if (xas_retry(&xas, page))
1152 VM_BUG_ON_PAGE(!PageLocked(page), page);
1153 VM_BUG_ON_PAGE(PageTail(page), page);
1155 rac->_batch_count += thp_nr_pages(page);
1165 * readahead_page_batch - Get a batch of pages to read.
1166 * @rac: The current readahead request.
1167 * @array: An array of pointers to struct page.
1169 * Context: The pages are locked and have an elevated refcount. The caller
1170 * should decreases the refcount once the page has been submitted for I/O
1171 * and unlock the page once all I/O to that page has completed.
1172 * Return: The number of pages placed in the array. 0 indicates the request
1175 #define readahead_page_batch(rac, array) \
1176 __readahead_batch(rac, array, ARRAY_SIZE(array))
1179 * readahead_pos - The byte offset into the file of this readahead request.
1180 * @rac: The readahead request.
1182 static inline loff_t readahead_pos(struct readahead_control *rac)
1184 return (loff_t)rac->_index * PAGE_SIZE;
1188 * readahead_length - The number of bytes in this readahead request.
1189 * @rac: The readahead request.
1191 static inline size_t readahead_length(struct readahead_control *rac)
1193 return rac->_nr_pages * PAGE_SIZE;
1197 * readahead_index - The index of the first page in this readahead request.
1198 * @rac: The readahead request.
1200 static inline pgoff_t readahead_index(struct readahead_control *rac)
1206 * readahead_count - The number of pages in this readahead request.
1207 * @rac: The readahead request.
1209 static inline unsigned int readahead_count(struct readahead_control *rac)
1211 return rac->_nr_pages;
1215 * readahead_batch_length - The number of bytes in the current batch.
1216 * @rac: The readahead request.
1218 static inline size_t readahead_batch_length(struct readahead_control *rac)
1220 return rac->_batch_count * PAGE_SIZE;
1223 static inline unsigned long dir_pages(struct inode *inode)
1225 return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>
1230 * folio_mkwrite_check_truncate - check if folio was truncated
1231 * @folio: the folio to check
1232 * @inode: the inode to check the folio against
1234 * Return: the number of bytes in the folio up to EOF,
1235 * or -EFAULT if the folio was truncated.
1237 static inline ssize_t folio_mkwrite_check_truncate(struct folio *folio,
1238 struct inode *inode)
1240 loff_t size = i_size_read(inode);
1241 pgoff_t index = size >> PAGE_SHIFT;
1242 size_t offset = offset_in_folio(folio, size);
1244 if (!folio->mapping)
1247 /* folio is wholly inside EOF */
1248 if (folio_next_index(folio) - 1 < index)
1249 return folio_size(folio);
1250 /* folio is wholly past EOF */
1251 if (folio->index > index || !offset)
1253 /* folio is partially inside EOF */
1258 * page_mkwrite_check_truncate - check if page was truncated
1259 * @page: the page to check
1260 * @inode: the inode to check the page against
1262 * Returns the number of bytes in the page up to EOF,
1263 * or -EFAULT if the page was truncated.
1265 static inline int page_mkwrite_check_truncate(struct page *page,
1266 struct inode *inode)
1268 loff_t size = i_size_read(inode);
1269 pgoff_t index = size >> PAGE_SHIFT;
1270 int offset = offset_in_page(size);
1272 if (page->mapping != inode->i_mapping)
1275 /* page is wholly inside EOF */
1276 if (page->index < index)
1278 /* page is wholly past EOF */
1279 if (page->index > index || !offset)
1281 /* page is partially inside EOF */
1286 * i_blocks_per_folio - How many blocks fit in this folio.
1287 * @inode: The inode which contains the blocks.
1288 * @folio: The folio.
1290 * If the block size is larger than the size of this folio, return zero.
1292 * Context: The caller should hold a refcount on the folio to prevent it
1294 * Return: The number of filesystem blocks covered by this folio.
1297 unsigned int i_blocks_per_folio(struct inode *inode, struct folio *folio)
1299 return folio_size(folio) >> inode->i_blkbits;
1303 unsigned int i_blocks_per_page(struct inode *inode, struct page *page)
1305 return i_blocks_per_folio(inode, page_folio(page));
1307 #endif /* _LINUX_PAGEMAP_H */