[PATCH] Add find_get_pages_contig(): contiguous variant of find_get_pages()

find_get_pages_contig() will break out if we hit a hole in the page cache.
From Andrew Morton, small modifications and documentation by me.

Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 9539efd..7a1af57 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -78,6 +78,8 @@
 				unsigned long index, gfp_t gfp_mask);
 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);