diff options
Diffstat (limited to 'include/linux/pagemap.h')
| -rw-r--r-- | include/linux/pagemap.h | 169 |
1 files changed, 149 insertions, 20 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 7de11dcd534d..c77b7c31b2e4 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -29,6 +29,7 @@ enum mapping_flags { AS_EXITING = 4, /* final truncate in progress */ /* writeback related tags are not used */ AS_NO_WRITEBACK_TAGS = 5, + AS_THP_SUPPORT = 6, /* THPs supported */ }; /** @@ -54,7 +55,8 @@ static inline void mapping_set_error(struct address_space *mapping, int error) __filemap_set_wb_err(mapping, error); /* Record it in superblock */ - errseq_set(&mapping->host->i_sb->s_wb_err, error); + if (mapping->host) + errseq_set(&mapping->host->i_sb->s_wb_err, error); /* Record it in flags for now, for legacy callers */ if (error == -ENOSPC) @@ -119,6 +121,40 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) m->gfp_mask = mask; } +static inline bool mapping_thp_support(struct address_space *mapping) +{ + return test_bit(AS_THP_SUPPORT, &mapping->flags); +} + +static inline int filemap_nr_thps(struct address_space *mapping) +{ +#ifdef CONFIG_READ_ONLY_THP_FOR_FS + return atomic_read(&mapping->nr_thps); +#else + return 0; +#endif +} + +static inline void filemap_nr_thps_inc(struct address_space *mapping) +{ +#ifdef CONFIG_READ_ONLY_THP_FOR_FS + if (!mapping_thp_support(mapping)) + atomic_inc(&mapping->nr_thps); +#else + WARN_ON_ONCE(1); +#endif +} + +static inline void filemap_nr_thps_dec(struct address_space *mapping) +{ +#ifdef CONFIG_READ_ONLY_THP_FOR_FS + if (!mapping_thp_support(mapping)) + atomic_dec(&mapping->nr_thps); +#else + WARN_ON_ONCE(1); +#endif +} + void release_pages(struct page **pages, int nr); /* @@ -278,6 +314,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, #define FGP_NOFS 0x00000010 #define FGP_NOWAIT 0x00000020 #define FGP_FOR_MMAP 0x00000040 +#define FGP_HEAD 0x00000080 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, int fgp_flags, gfp_t cache_gfp_mask); @@ -309,18 +346,37 @@ static inline struct page *find_get_page_flags(struct address_space *mapping, * @mapping: the address_space to search * @offset: the page index * - * Looks up the page cache slot at @mapping & @offset. If there is a + * Looks up the page cache entry at @mapping & @offset. If there is a * page cache page, it is returned locked and with an increased * refcount. * - * Otherwise, %NULL is returned. - * - * find_lock_page() may sleep. + * Context: May sleep. + * Return: A struct page or %NULL if there is no page in the cache for this + * index. */ static inline struct page *find_lock_page(struct address_space *mapping, - pgoff_t offset) + pgoff_t index) +{ + return pagecache_get_page(mapping, index, FGP_LOCK, 0); +} + +/** + * find_lock_head - Locate, pin and lock a pagecache page. + * @mapping: The address_space to search. + * @offset: The page index. + * + * Looks up the page cache entry at @mapping & @offset. If there is a + * page cache page, its head page is returned locked and with an increased + * refcount. + * + * Context: May sleep. + * Return: A struct page which is !PageTail, or %NULL if there is no page + * in the cache for this index. + */ +static inline struct page *find_lock_head(struct address_space *mapping, + pgoff_t index) { - return pagecache_get_page(mapping, offset, FGP_LOCK, 0); + return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0); } /** @@ -371,6 +427,15 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, mapping_gfp_mask(mapping)); } +/* Does this page contain this index? */ +static inline bool thp_contains(struct page *head, pgoff_t index) +{ + /* HugeTLBfs indexes the page cache in units of hpage_size */ + if (PageHuge(head)) + return head->index == index; + return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL)); +} + /* * Given the page we found in the page cache, return the page corresponding * to this index in the file @@ -384,8 +449,6 @@ static inline struct page *find_subpage(struct page *head, pgoff_t index) return head + (index & (thp_nr_pages(head) - 1)); } -struct page *find_get_entry(struct address_space *mapping, pgoff_t offset); -struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset); unsigned find_get_entries(struct address_space *mapping, pgoff_t start, unsigned int nr_entries, struct page **entries, pgoff_t *indices); @@ -698,17 +761,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask); void delete_from_page_cache_batch(struct address_space *mapping, struct pagevec *pvec); -#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE) - -void page_cache_sync_readahead(struct address_space *, struct file_ra_state *, - struct file *, pgoff_t index, unsigned long req_count); -void page_cache_async_readahead(struct address_space *, struct file_ra_state *, - struct file *, struct page *, pgoff_t index, - unsigned long req_count); -void page_cache_readahead_unbounded(struct address_space *, struct file *, - pgoff_t index, unsigned long nr_to_read, - unsigned long lookahead_count); - /* * Like add_to_page_cache_locked, but used to add newly allocated pages: * the page is new, so we can just run __SetPageLocked() against it. @@ -749,6 +801,67 @@ struct readahead_control { unsigned int _batch_count; }; +#define DEFINE_READAHEAD(rac, f, m, i) \ + struct readahead_control rac = { \ + .file = f, \ + .mapping = m, \ + ._index = i, \ + } + +#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE) + +void page_cache_ra_unbounded(struct readahead_control *, + unsigned long nr_to_read, unsigned long lookahead_count); +void page_cache_sync_ra(struct readahead_control *, struct file_ra_state *, + unsigned long req_count); +void page_cache_async_ra(struct readahead_control *, struct file_ra_state *, + struct page *, unsigned long req_count); + +/** + * page_cache_sync_readahead - generic file readahead + * @mapping: address_space which holds the pagecache and I/O vectors + * @ra: file_ra_state which holds the readahead state + * @file: Used by the filesystem for authentication. + * @index: Index of first page to be read. + * @req_count: Total number of pages being read by the caller. + * + * page_cache_sync_readahead() should be called when a cache miss happened: + * it will submit the read. The readahead logic may decide to piggyback more + * pages onto the read request if access patterns suggest it will improve + * performance. + */ +static inline +void page_cache_sync_readahead(struct address_space *mapping, + struct file_ra_state *ra, struct file *file, pgoff_t index, + unsigned long req_count) +{ + DEFINE_READAHEAD(ractl, file, mapping, index); + page_cache_sync_ra(&ractl, ra, req_count); +} + +/** + * page_cache_async_readahead - file readahead for marked pages + * @mapping: address_space which holds the pagecache and I/O vectors + * @ra: file_ra_state which holds the readahead state + * @file: Used by the filesystem for authentication. + * @page: The page at @index which triggered the readahead call. + * @index: Index of first page to be read. + * @req_count: Total number of pages being read by the caller. + * + * page_cache_async_readahead() should be called when a page is used which + * is marked as PageReadahead; this is a marker to suggest that the application + * has used up enough of the readahead window that we should start pulling in + * more pages. + */ +static inline +void page_cache_async_readahead(struct address_space *mapping, + struct file_ra_state *ra, struct file *file, + struct page *page, pgoff_t index, unsigned long req_count) +{ + DEFINE_READAHEAD(ractl, file, mapping, index); + page_cache_async_ra(&ractl, ra, page, req_count); +} + /** * readahead_page - Get the next page to read. * @rac: The current readahead request. @@ -899,4 +1012,20 @@ static inline int page_mkwrite_check_truncate(struct page *page, return offset; } +/** + * i_blocks_per_page - How many blocks fit in this page. + * @inode: The inode which contains the blocks. + * @page: The page (head page if the page is a THP). + * + * If the block size is larger than the size of this page, return zero. + * + * Context: The caller should hold a refcount on the page to prevent it + * from being split. + * Return: The number of filesystem blocks covered by this page. + */ +static inline +unsigned int i_blocks_per_page(struct inode *inode, struct page *page) +{ + return thp_size(page) >> inode->i_blkbits; +} #endif /* _LINUX_PAGEMAP_H */ |