mm: implement find_get_pages_range()

[sfrench/cifs-2.6.git] / mm / swap.c

diff --git a/mm/swap.c b/mm/swap.c
index 60b1d2a758522a6b7ebb02aae182dd554e22bdab..e06e9aa2478ea13dac02a1d5206a8bc54fb4f4ee 100644 (file)
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -946,28 +946,35 @@ void pagevec_remove_exceptionals(struct pagevec *pvec)
 }
 
 /**
- * pagevec_lookup - gang pagecache lookup
+ * pagevec_lookup_range - gang pagecache lookup
  * @pvec:      Where the resulting pages are placed
  * @mapping:   The address_space to search
  * @start:     The starting page index
+ * @end:       The final page index
  * @nr_pages:  The maximum number of pages
  *
- * pagevec_lookup() will search for and return a group of up to @nr_pages pages
- * in the mapping.  The pages are placed in @pvec.  pagevec_lookup() takes a
+ * pagevec_lookup_range() will search for and return a group of up to @nr_pages
+ * pages in the mapping starting from index @start and upto index @end
+ * (inclusive).  The pages are placed in @pvec.  pagevec_lookup() takes a
  * reference against the pages in @pvec.
  *
  * The search returns a group of mapping-contiguous pages with ascending
- * indexes.  There may be holes in the indices due to not-present pages.
+ * indexes.  There may be holes in the indices due to not-present pages. We
+ * also update @start to index the next page for the traversal.
  *
- * pagevec_lookup() returns the number of pages which were found.
+ * pagevec_lookup_range() returns the number of pages which were found. If this
+ * number is smaller than @nr_pages, the end of specified range has been
+ * reached.
  */
-unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
-               pgoff_t start, unsigned nr_pages)
+unsigned pagevec_lookup_range(struct pagevec *pvec,
+               struct address_space *mapping, pgoff_t *start, pgoff_t end,
+               unsigned nr_pages)
 {
-       pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages);
+       pvec->nr = find_get_pages_range(mapping, start, end, nr_pages,
+                                       pvec->pages);
        return pagevec_count(pvec);
 }
-EXPORT_SYMBOL(pagevec_lookup);
+EXPORT_SYMBOL(pagevec_lookup_range);
 
 unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
                pgoff_t *index, int tag, unsigned nr_pages)