diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/filemap.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 3ef20739e72..fd57442186c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -697,6 +697,38 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start, return ret; } +/** + * find_get_pages_contig - gang contiguous pagecache lookup + * @mapping: The address_space to search + * @index: 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. + */ +unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, + unsigned int nr_pages, struct page **pages) +{ + unsigned int i; + unsigned int ret; + + read_lock_irq(&mapping->tree_lock); + ret = radix_tree_gang_lookup(&mapping->page_tree, + (void **)pages, index, nr_pages); + for (i = 0; i < ret; i++) { + if (pages[i]->mapping == NULL || pages[i]->index != index) + break; + + page_cache_get(pages[i]); + index++; + } + read_unlock_irq(&mapping->tree_lock); + return i; +} + /* * 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. |