[PATCH] mpage writepages range limit fix

Safeguard to make sure we break out of pagevec_lookup_tag loop if we are
beyond the specified range.
Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/mpage.c

@@ -654,7 +654,8 @@ mpage_writepages(struct address_space *mapping,
 		scanned = 1;
 	}
 retry:
-	while (!done && (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
+	while (!done && (index <= end) &&
+			(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
 			PAGECACHE_TAG_DIRTY,
 			min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
 		unsigned i;