1 files changed, 51 insertions, 0 deletions

diff --git a/mm/swap.c b/mm/swap.c
index 0092097b3f4c..c8048d71c642 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -948,6 +948,57 @@ void __pagevec_lru_add(struct pagevec *pvec)
 EXPORT_SYMBOL(__pagevec_lru_add);
 
 /**
+ * pagevec_lookup_entries - gang pagecache lookup
+ * @pvec:       Where the resulting entries are placed
+ * @mapping:    The address_space to search
+ * @start:      The starting entry index
+ * @nr_entries: The maximum number of entries
+ * @indices:    The cache indices corresponding to the entries in @pvec
+ *
+ * pagevec_lookup_entries() will search for and return a group of up
+ * to @nr_entries pages and shadow entries in the mapping.  All
+ * entries are placed in @pvec.  pagevec_lookup_entries() takes a
+ * reference against actual pages in @pvec.
+ *
+ * The search returns a group of mapping-contiguous entries with
+ * ascending indexes.  There may be holes in the indices due to
+ * not-present entries.
+ *
+ * pagevec_lookup_entries() returns the number of entries which were
+ * found.
+ */
+unsigned pagevec_lookup_entries(struct pagevec *pvec,
+                                struct address_space *mapping,
+                                pgoff_t start, unsigned nr_pages,
+                                pgoff_t *indices)
+{
+        pvec->nr = find_get_entries(mapping, start, nr_pages,
+                                    pvec->pages, indices);
+        return pagevec_count(pvec);
+}
+
+/**
+ * pagevec_remove_exceptionals - pagevec exceptionals pruning
+ * @pvec:       The pagevec to prune
+ *
+ * pagevec_lookup_entries() fills both pages and exceptional radix
+ * tree entries into the pagevec.  This function prunes all
+ * exceptionals from @pvec without leaving holes, so that it can be
+ * passed on to page-only pagevec operations.
+ */
+void pagevec_remove_exceptionals(struct pagevec *pvec)
+{
+        int i, j;
+
+        for (i = 0, j = 0; i < pagevec_count(pvec); i++) {
+                struct page *page = pvec->pages[i];
+                if (!radix_tree_exceptional_entry(page))
+                        pvec->pages[j++] = page;
+        }
+        pvec->nr = j;
+}
+
+/**
  * pagevec_lookup - gang pagecache lookup
  * @pvec:       Where the resulting pages are placed
  * @mapping:    The address_space to search