159 void release_pages(struct page **pages, int nr);
162  * speculatively take a reference to a page.
163  * If the page is free (_refcount == 0), then _refcount is untouched, and 0
167  * been used to lookup the page in the pagecache radix-tree (or page table):
173  * page has been finished with, no matter what it is subsequently allocated
180  * 1. find page in radix tree
182  * 3. check the page is still in pagecache (if no, goto 1)
187  * B. remove page from pagecache
188  * C. free the page
193  *   subsequently, B will complete and 1 will find no page, causing the
196  * It is possible that between 1 and 2, the page is removed then the exact same
197  * page is inserted into the same position in pagecache. That's OK: the
202  * will find the page or it will not. Likewise, the old find_get_page could run
205 static inline int __page_cache_add_speculative(struct page *page, int count)  in __page_cache_add_speculative()  argument
216 	 * found a page in the radix tree here, we have pinned its refcount by  in __page_cache_add_speculative()
220 	VM_BUG_ON_PAGE(page_count(page) == 0, page);  in __page_cache_add_speculative()
221 	page_ref_add(page, count);  in __page_cache_add_speculative()
224 	if (unlikely(!page_ref_add_unless(page, count, 0))) {  in __page_cache_add_speculative()
226 		 * Either the page has been freed, or will be freed.  in __page_cache_add_speculative()
233 	VM_BUG_ON_PAGE(PageTail(page), page);  in __page_cache_add_speculative()
238 static inline int page_cache_get_speculative(struct page *page)  in page_cache_get_speculative()  argument
240 	return __page_cache_add_speculative(page, 1);  in page_cache_get_speculative()
243 static inline int page_cache_add_speculative(struct page *page, int count)  in page_cache_add_speculative()  argument
245 	return __page_cache_add_speculative(page, count);  in page_cache_add_speculative()
249  * attach_page_private - Attach private data to a page.
250  * @page: Page to attach data to.
251  * @data: Data to attach to page.
253  * Attaching private data to a page increments the page's reference count.
254  * The data must be detached before the page will be freed.
256 static inline void attach_page_private(struct page *page, void *data)  in attach_page_private()  argument
258 	get_page(page);  in attach_page_private()
259 	set_page_private(page, (unsigned long)data);  in attach_page_private()
260 	SetPagePrivate(page);  in attach_page_private()
264  * detach_page_private - Detach private data from a page.
265  * @page: Page to detach data from.
267  * Removes the data that was previously attached to the page and decrements
268  * the refcount on the page.
270  * Return: Data that was attached to the page.
272 static inline void *detach_page_private(struct page *page)  in detach_page_private()  argument
274 	void *data = (void *)page_private(page);  in detach_page_private()
276 	if (!PagePrivate(page))  in detach_page_private()
278 	ClearPagePrivate(page);  in detach_page_private()
279 	set_page_private(page, 0);  in detach_page_private()
280 	put_page(page);  in detach_page_private()
286 extern struct page *__page_cache_alloc(gfp_t gfp);
288 static inline struct page *__page_cache_alloc(gfp_t gfp)  in __page_cache_alloc()
294 static inline struct page *page_cache_alloc(struct address_space *x)  in page_cache_alloc()
301 typedef int filler_t(void *, struct page *);
317 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
321  * find_get_page - find and get a page reference
323  * @offset: the page index
325  * Looks up the page cache slot at @mapping & @offset.  If there is a
326  * page cache page, it is returned with an increased refcount.
330 static inline struct page *find_get_page(struct address_space *mapping,  in find_get_page()
336 static inline struct page *find_get_page_flags(struct address_space *mapping,  in find_get_page_flags()
343  * find_lock_page - locate, pin and lock a pagecache page
345  * @index: the page index
347  * Looks up the page cache entry at @mapping & @index.  If there is a
348  * page cache page, it is returned locked and with an increased
352  * Return: A struct page or %NULL if there is no page in the cache for this
355 static inline struct page *find_lock_page(struct address_space *mapping,  in find_lock_page()
362  * find_lock_head - Locate, pin and lock a pagecache page.
364  * @index: The page index.
366  * Looks up the page cache entry at @mapping & @index.  If there is a
367  * page cache page, its head page is returned locked and with an increased
371  * Return: A struct page which is !PageTail, or %NULL if there is no page
374 static inline struct page *find_lock_head(struct address_space *mapping,  in find_lock_head()
381  * find_or_create_page - locate or add a pagecache page
382  * @mapping: the page's address_space
383  * @index: the page's index into the mapping
384  * @gfp_mask: page allocation mode
386  * Looks up the page cache slot at @mapping & @offset.  If there is a
387  * page cache page, it is returned locked and with an increased
390  * If the page is not present, a new page is allocated using @gfp_mask
391  * and added to the page cache and the VM's LRU list.  The page is
399 static inline struct page *find_or_create_page(struct address_space *mapping,  in find_or_create_page()
408  * grab_cache_page_nowait - returns locked page at given index in given cache
410  * @index: the page index
412  * Same as grab_cache_page(), but do not wait if the page is unavailable.
414  * be regenerated if the page couldn't be grabbed.  This routine should
415  * be safe to call while holding the lock for another page.
417  * Clear __GFP_FS when allocating the page to avoid recursion into the fs
418  * and deadlock against the caller's locked page.
420 static inline struct page *grab_cache_page_nowait(struct address_space *mapping,  in grab_cache_page_nowait()
428 /* Does this page contain this index? */
429 static inline bool thp_contains(struct page *head, pgoff_t index)  in thp_contains()
431 	/* HugeTLBfs indexes the page cache in units of hpage_size */  in thp_contains()
438  * Given the page we found in the page cache, return the page corresponding
441 static inline struct page *find_subpage(struct page *head, pgoff_t index)  in find_subpage()
443 	/* HugeTLBfs wants the head page regardless */  in find_subpage()
451 			  unsigned int nr_entries, struct page **entries,
455 			struct page **pages);
458 			struct page **pages)  in find_get_pages()
464 			       unsigned int nr_pages, struct page **pages);
467 			struct page **pages);
470 			struct page **pages)  in find_get_pages_tag()
476 struct page *grab_cache_page_write_begin(struct address_space *mapping,
480  * Returns locked page at given index in given cache, creating it if needed.
482 static inline struct page *grab_cache_page(struct address_space *mapping,  in grab_cache_page()
488 extern struct page * read_cache_page(struct address_space *mapping,
490 extern struct page * read_cache_page_gfp(struct address_space *mapping,
495 static inline struct page *read_mapping_page(struct address_space *mapping,  in read_mapping_page()
502  * Get index of the page within radix-tree (but not for hugetlb pages).
505 static inline pgoff_t page_to_index(struct page *page)  in page_to_index()  argument
509 	if (likely(!PageTransTail(page)))  in page_to_index()
510 		return page->index;  in page_to_index()
514 	 *  head page  in page_to_index()
516 	pgoff = compound_head(page)->index;  in page_to_index()
517 	pgoff += page - compound_head(page);  in page_to_index()
521 extern pgoff_t hugetlb_basepage_index(struct page *page);
527 static inline pgoff_t page_to_pgoff(struct page *page)  in page_to_pgoff()  argument
529 	if (unlikely(PageHuge(page)))  in page_to_pgoff()
530 		return hugetlb_basepage_index(page);  in page_to_pgoff()
531 	return page_to_index(page);  in page_to_pgoff()
535  * Return byte-offset into filesystem object for page.
537 static inline loff_t page_offset(struct page *page)  in page_offset()  argument
539 	return ((loff_t)page->index) << PAGE_SHIFT;  in page_offset()
542 static inline loff_t page_file_offset(struct page *page)  in page_file_offset()  argument
544 	return ((loff_t)page_index(page)) << PAGE_SHIFT;  in page_file_offset()
562 	struct page *page;  member
568 	struct page *page;  member
576 	if (wait_page->page != key->page)  in wake_page_match()
586 extern void __lock_page(struct page *page);
587 extern int __lock_page_killable(struct page *page);
588 extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);
589 extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
591 extern void unlock_page(struct page *page);
594  * Return true if the page was successfully locked
596 static inline int trylock_page(struct page *page)  in trylock_page()  argument
598 	page = compound_head(page);  in trylock_page()
599 	return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));  in trylock_page()
603  * lock_page may only be called if we have the page's inode pinned.
605 static inline __sched void lock_page(struct page *page)  in lock_page()  argument
608 	if (!trylock_page(page))  in lock_page()
609 		__lock_page(page);  in lock_page()
614  * signals.  It returns 0 if it locked the page and -EINTR if it was
617 static inline __sched int lock_page_killable(struct page *page)  in lock_page_killable()  argument
620 	if (!trylock_page(page))  in lock_page_killable()
621 		return __lock_page_killable(page);  in lock_page_killable()
626  * lock_page_async - Lock the page, unless this would block. If the page
627  * is already locked, then queue a callback when the page becomes unlocked.
630  * Returns 0 if the page is locked successfully, or -EIOCBQUEUED if the page
633 static inline __sched int lock_page_async(struct page *page,  in lock_page_async()  argument
636 	if (!trylock_page(page))  in lock_page_async()
637 		return __lock_page_async(page, wait);  in lock_page_async()
642  * lock_page_or_retry - Lock the page, unless this would block and the
648 static inline __sched int lock_page_or_retry(struct page *page, struct mm_struct *mm,  in lock_page_or_retry()  argument
652 	return trylock_page(page) || __lock_page_or_retry(page, mm, flags);  in lock_page_or_retry()
659 extern void wait_on_page_bit(struct page *page, int bit_nr);
660 extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
663  * Wait for a page to be unlocked.
665  * This must be called with the caller "holding" the page,
666  * ie with increased "page->count" so that the page won't
669 static inline __sched void wait_on_page_locked(struct page *page)  in wait_on_page_locked()  argument
671 	if (PageLocked(page))  in wait_on_page_locked()
672 		wait_on_page_bit(compound_head(page), PG_locked);  in wait_on_page_locked()
675 static inline __sched int wait_on_page_locked_killable(struct page *page)  in wait_on_page_locked_killable()  argument
677 	if (!PageLocked(page))  in wait_on_page_locked_killable()
679 	return wait_on_page_bit_killable(compound_head(page), PG_locked);  in wait_on_page_locked_killable()
682 extern void put_and_wait_on_page_locked(struct page *page);
684 void wait_on_page_writeback(struct page *page);
685 extern void end_page_writeback(struct page *page);
686 void wait_for_stable_page(struct page *page);
688 void page_endio(struct page *page, bool is_write, int err);
691  * Add an arbitrary waiter to a page's wait queue
693 extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
717 	/* Check whether the range spilled into the next page. */  in fault_in_pages_writeable()
742 	/* Check whether the range spilled into the next page. */  in fault_in_pages_readable()
752 int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
754 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
756 extern void delete_from_page_cache(struct page *page);
757 extern void __delete_from_page_cache(struct page *page, void *shadow);
758 int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
764  * the page is new, so we can just run __SetPageLocked() against it.
766 static inline int add_to_page_cache(struct page *page,  in add_to_page_cache()  argument
771 	__SetPageLocked(page);  in add_to_page_cache()
772 	error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);  in add_to_page_cache()
774 		__ClearPageLocked(page);  in add_to_page_cache()
784  * each page in the request.
816 		struct page *, unsigned long req_count);
823  * @index: Index of first page to be read.
845  * @page: The page at @index which triggered the readahead call.
846  * @index: Index of first page to be read.
849  * page_cache_async_readahead() should be called when a page is used which
857 		struct page *page, pgoff_t index, unsigned long req_count)  in page_cache_async_readahead()  argument
860 	page_cache_async_ra(&ractl, ra, page, req_count);  in page_cache_async_readahead()
864  * readahead_page - Get the next page to read.
867  * Context: The page is locked and has an elevated refcount.  The caller
868  * should decreases the refcount once the page has been submitted for I/O
869  * and unlock the page once all I/O to that page has completed.
870  * Return: A pointer to the next page, or %NULL if we are done.
872 static inline struct page *readahead_page(struct readahead_control *rac)  in readahead_page()
874 	struct page *page;  in readahead_page()  local
885 	page = xa_load(&rac->mapping->i_pages, rac->_index);  in readahead_page()
886 	VM_BUG_ON_PAGE(!PageLocked(page), page);  in readahead_page()
887 	rac->_batch_count = thp_nr_pages(page);  in readahead_page()
889 	return page;  in readahead_page()
893 		struct page **array, unsigned int array_sz)  in __readahead_batch()
897 	struct page *page;  in __readahead_batch()  local
906 	xas_for_each(&xas, page, rac->_index + rac->_nr_pages - 1) {  in __readahead_batch()
907 		if (xas_retry(&xas, page))  in __readahead_batch()
909 		VM_BUG_ON_PAGE(!PageLocked(page), page);  in __readahead_batch()
910 		VM_BUG_ON_PAGE(PageTail(page), page);  in __readahead_batch()
911 		array[i++] = page;  in __readahead_batch()
912 		rac->_batch_count += thp_nr_pages(page);  in __readahead_batch()
915 		 * The page cache isn't using multi-index entries yet,  in __readahead_batch()
917 		 * next index.  This can be removed once the page cache  in __readahead_batch()
920 		if (PageHead(page))  in __readahead_batch()
934  * @array: An array of pointers to struct page.
937  * should decreases the refcount once the page has been submitted for I/O
938  * and unlock the page once all I/O to that page has completed.
964  * readahead_index - The index of the first page in this readahead request.
988  * page_mkwrite_check_truncate - check if page was truncated
989  * @page: the page to check
990  * @inode: the inode to check the page against
992  * Returns the number of bytes in the page up to EOF,
993  * or -EFAULT if the page was truncated.
995 static inline int page_mkwrite_check_truncate(struct page *page,  in page_mkwrite_check_truncate()  argument
1002 	if (page->mapping != inode->i_mapping)  in page_mkwrite_check_truncate()
1005 	/* page is wholly inside EOF */  in page_mkwrite_check_truncate()
1006 	if (page->index < index)  in page_mkwrite_check_truncate()
1008 	/* page is wholly past EOF */  in page_mkwrite_check_truncate()
1009 	if (page->index > index || !offset)  in page_mkwrite_check_truncate()
1011 	/* page is partially inside EOF */  in page_mkwrite_check_truncate()
1016  * i_blocks_per_page - How many blocks fit in this page.
1018  * @page: The page (head page if the page is a THP).
1020  * If the block size is larger than the size of this page, return zero.
1022  * Context: The caller should hold a refcount on the page to prevent it
1024  * Return: The number of filesystem blocks covered by this page.
1027 unsigned int i_blocks_per_page(struct inode *inode, struct page *page)  in i_blocks_per_page()  argument
1029 	return thp_size(page) >> inode->i_blkbits;  in i_blocks_per_page()