diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 249b1b5964c762bd7515d5045f771d5d26cd9cfe..5bbd6780f205103066bbf8b7d0d96959d5cbaed3 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -353,8 +353,16 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
unsigned int nr_entries, struct page **entries,
pgoff_t *indices);
-unsigned find_get_pages(struct address_space *mapping, pgoff_t *start,
- unsigned int nr_pages, struct page **pages);
+unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
+ pgoff_t end, unsigned int nr_pages,
+ struct page **pages);
+static inline unsigned find_get_pages(struct address_space *mapping,
+ pgoff_t *start, unsigned int nr_pages,
+ struct page **pages)
+{
+ return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages,
+ 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,
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index c395a5bb58b265cf3569441a820b79f52acb2fc0..7df056910437d1e4feb595fc2744532770b02b0f 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -27,8 +27,17 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec,
pgoff_t start, unsigned nr_entries,
pgoff_t *indices);
void pagevec_remove_exceptionals(struct pagevec *pvec);
-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);
+static inline unsigned pagevec_lookup(struct pagevec *pvec,
+ struct address_space *mapping,
+ pgoff_t *start, unsigned nr_pages)
+{
+ return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1,
+ nr_pages);
+}
+
unsigned pagevec_lookup_tag(struct pagevec *pvec,
struct address_space *mapping, pgoff_t *index, int tag,
unsigned nr_pages);
diff --git a/mm/filemap.c b/mm/filemap.c
index ab9011408d81f116def93f45dd6da41081ddfbec..129883f160a7ba12e4b327dcf07a58bab4af0ce1 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1557,24 +1557,29 @@ unsigned find_get_entries(struct address_space *mapping,
}
/**
- * find_get_pages - gang pagecache lookup
+ * find_get_pages_range - gang pagecache lookup
* @mapping: The address_space to search
* @start: The starting page index
+ * @end: The final page index (inclusive)
* @nr_pages: The maximum number of pages
* @pages: Where the resulting pages are placed
*
- * find_get_pages() will search for and return a group of up to
- * @nr_pages pages in the mapping. The pages are placed at @pages.
- * find_get_pages() takes a reference against the returned pages.
+ * find_get_pages_range() will search for and return a group of up to @nr_pages
+ * pages in the mapping starting at index @start and up to index @end
+ * (inclusive). The pages are placed at @pages. find_get_pages_range() takes
+ * a reference against the returned pages.
*
* The search returns a group of mapping-contiguous pages with ascending
* 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.
*
- * find_get_pages() returns the number of pages which were found.
+ * find_get_pages_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 find_get_pages(struct address_space *mapping, pgoff_t *start,
- unsigned int nr_pages, struct page **pages)
+unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
+ pgoff_t end, unsigned int nr_pages,
+ struct page **pages)
{
struct radix_tree_iter iter;
void **slot;
@@ -1586,6 +1591,9 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t *start,
rcu_read_lock();
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, *start) {
struct page *head, *page;
+
+ if (iter.index > end)
+ break;
repeat:
page = radix_tree_deref_slot(slot);
if (unlikely(!page))
@@ -1621,15 +1629,25 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t *start,
}
pages[ret] = page;
- if (++ret == nr_pages)
- break;
+ if (++ret == nr_pages) {
+ *start = pages[ret - 1]->index + 1;
+ goto out;
+ }
}
+ /*
+ * We come here when there is no page beyond @end. We take care to not
+ * overflow the index @start as it confuses some of the callers. This
+ * breaks the iteration when there is page at index -1 but that is
+ * already broken anyway.
+ */
+ if (end == (pgoff_t)-1)
+ *start = (pgoff_t)-1;
+ else
+ *start = end + 1;
+out:
rcu_read_unlock();
- if (ret)
- *start = pages[ret - 1]->index + 1;
-
return ret;
}
diff --git a/mm/swap.c b/mm/swap.c
index 4bffd1198ce50365352ed2d1f8ce6104cf5e95e2..e06e9aa2478ea13dac02a1d5206a8bc54fb4f4ee 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -946,29 +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. 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)