diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pagemap.h | 142 | ||||
| -rw-r--r-- | include/linux/radix-tree.h | 25 |
2 files changed, 142 insertions, 25 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 97354102794d..db8e15287ea0 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -324,18 +324,136 @@ static inline struct page *grab_cache_page_nowait(struct address_space *mapping, 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); -unsigned find_get_pages(struct address_space *mapping, pgoff_t start, - unsigned int nr_pages, struct page **pages); -unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start, - unsigned int nr_pages, struct page **pages); -unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index, - int tag, unsigned int nr_pages, struct page **pages); -unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start, - int tag, unsigned int nr_entries, - struct page **entries, pgoff_t *indices); + +unsigned __find_get_pages(struct address_space *mapping, + pgoff_t start, pgoff_t end, + unsigned nr_entries, struct page **entries, + pgoff_t *indices, unsigned flags); + +/** + * find_get_entries - gang pagecache lookup + * @mapping: The address_space to search + * @start: The starting page cache index + * @nr_entries: The maximum number of entries + * @entries: Where the resulting entries are placed + * @indices: The cache indices corresponding to the entries in @entries + * + * find_get_entries() will search for and return a group of up to + * @nr_entries entries in the mapping. The entries are placed at + * @entries. find_get_entries() takes a reference against any actual + * pages it returns. + * + * The search returns a group of mapping-contiguous page cache entries + * with ascending indexes. There may be holes in the indices due to + * not-present pages. + * + * Any shadow entries of evicted pages, or swap entries from + * shmem/tmpfs, are included in the returned array. + * + * find_get_entries() returns the number of pages and shadow entries + * which were found. + */ +static inline unsigned find_get_entries(struct address_space *mapping, + pgoff_t start, unsigned nr_entries, + struct page **entries, pgoff_t *indices) +{ + return __find_get_pages(mapping, start, ULONG_MAX, + nr_entries, entries, indices, + RADIX_TREE_ITER_EXCEPTIONAL); +} + +/** + * find_get_pages - gang pagecache lookup + * @mapping: The address_space to search + * @start: The starting page index + * @nr_pages: The maximum number of pages + * @pages: Where the resulting pages are placed + * + * find_get_pages() will search for and return a group of up to + * @nr_pages pages in the mapping. The pages are placed at @pages. + * find_get_pages() takes a reference against the returned pages. + * + * The search returns a group of mapping-contiguous pages with ascending + * indexes. There may be holes in the indices due to not-present pages. + * + * find_get_pages() returns the number of pages which were found. + */ +static inline unsigned find_get_pages(struct address_space *mapping, + pgoff_t start, unsigned nr_pages, + struct page **pages) +{ + return __find_get_pages(mapping, start, ULONG_MAX, + nr_pages, pages, NULL, 0); +} + +/** + * find_get_pages_contig - gang contiguous pagecache lookup + * @mapping: The address_space to search + * @start: The starting page index + * @nr_pages: The maximum number of pages + * @pages: Where the resulting pages are placed + * + * find_get_pages_contig() works exactly like find_get_pages(), except + * that the returned number of pages are guaranteed to be contiguous. + * + * find_get_pages_contig() returns the number of pages which were found. + */ +static inline unsigned find_get_pages_contig(struct address_space *mapping, + pgoff_t start, unsigned nr_pages, + struct page **pages) +{ + return __find_get_pages(mapping, start, ULONG_MAX, + nr_pages, pages, NULL, + RADIX_TREE_ITER_CONTIG); +} + +/** + * find_get_pages_tag - find and return pages that match @tag + * @mapping: the address_space to search + * @index: the starting page index + * @tag: the tag index + * @nr_pages: the maximum number of pages + * @pages: where the resulting pages are placed + * + * Like find_get_pages, except we only return pages which are tagged with + * @tag. We update @index to index the next page for the traversal. + */ +static inline unsigned find_get_pages_tag(struct address_space *mapping, + pgoff_t *index, int tag, + unsigned nr_pages, struct page **pages) +{ + unsigned ret; + + ret = __find_get_pages(mapping, *index, ULONG_MAX, + nr_pages, pages, NULL, + RADIX_TREE_ITER_TAGGED|tag); + if (ret) + *index = pages[ret - 1]->index + 1; + + return ret; +} + +/** + * find_get_entries_tag - find and return entries that match @tag + * @mapping: the address_space to search + * @start: the starting page cache index + * @tag: the tag index + * @nr_entries: the maximum number of entries + * @entries: where the resulting entries are placed + * @indices: the cache indices corresponding to the entries in @entries + * + * Like find_get_entries, except we only return entries which are tagged with + * @tag. + */ +static inline unsigned find_get_entries_tag(struct address_space *mapping, + pgoff_t start, int tag, unsigned nr_entries, + struct page **entries, pgoff_t *indices) +{ + return __find_get_pages(mapping, start, ULONG_MAX, + nr_entries, entries, indices, + RADIX_TREE_ITER_EXCEPTIONAL| + RADIX_TREE_ITER_TAGGED|tag); +} struct page *grab_cache_page_write_begin(struct address_space *mapping, pgoff_t index, unsigned flags); diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index eca6f626c16e..a83a42770f41 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -354,6 +354,8 @@ static inline unsigned int iter_shift(struct radix_tree_iter *iter) #define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */ #define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */ #define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */ +#define RADIX_TREE_ITER_EXCEPTIONAL 0x0400 /* include exceptional entries */ + /* used by __find_get_pages() */ /** * radix_tree_iter_init - initialize radix tree iterator @@ -520,6 +522,11 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) return NULL; } +#define __radix_tree_for_each_slot(slot, root, iter, start, flags) \ + for (slot = radix_tree_iter_init(iter, start) ; \ + slot || (slot = radix_tree_next_chunk(root, iter, flags)); \ + slot = radix_tree_next_slot(slot, iter, flags)) + /** * radix_tree_for_each_slot - iterate over non-empty slots * @@ -531,9 +538,7 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) * @slot points to radix tree slot, @iter->index contains its index. */ #define radix_tree_for_each_slot(slot, root, iter, start) \ - for (slot = radix_tree_iter_init(iter, start) ; \ - slot || (slot = radix_tree_next_chunk(root, iter, 0)) ; \ - slot = radix_tree_next_slot(slot, iter, 0)) + __radix_tree_for_each_slot(slot, root, iter, start, 0) /** * radix_tree_for_each_contig - iterate over contiguous slots @@ -546,11 +551,8 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) * @slot points to radix tree slot, @iter->index contains its index. */ #define radix_tree_for_each_contig(slot, root, iter, start) \ - for (slot = radix_tree_iter_init(iter, start) ; \ - slot || (slot = radix_tree_next_chunk(root, iter, \ - RADIX_TREE_ITER_CONTIG)) ; \ - slot = radix_tree_next_slot(slot, iter, \ - RADIX_TREE_ITER_CONTIG)) + __radix_tree_for_each_slot(slot, root, iter, start, \ + RADIX_TREE_ITER_CONTIG) /** * radix_tree_for_each_tagged - iterate over tagged slots @@ -564,10 +566,7 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) * @slot points to radix tree slot, @iter->index contains its index. */ #define radix_tree_for_each_tagged(slot, root, iter, start, tag) \ - for (slot = radix_tree_iter_init(iter, start) ; \ - slot || (slot = radix_tree_next_chunk(root, iter, \ - RADIX_TREE_ITER_TAGGED | tag)) ; \ - slot = radix_tree_next_slot(slot, iter, \ - RADIX_TREE_ITER_TAGGED)) + __radix_tree_for_each_slot(slot, root, iter, start, \ + RADIX_TREE_ITER_TAGGED|tag) #endif /* _LINUX_RADIX_TREE_H */ |