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authorDavid Woodhouse <dwmw2@infradead.org>2006-05-03 13:30:35 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2006-05-03 13:30:35 +0100
commitedc4ff7c08e9885c40e60c4fb39fa42cc91a0602 (patch)
treef375d28043dd4457428a841167dc93d760ba9a46 /mm/filemap.c
parentcbb9a56177b16294ed347ba7fcb1c66c8adb5dc4 (diff)
parente17df688f7064dae1417ce425dd1e4b71d24d63b (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c32
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.