[PATCH] Cleanup read_pages()

Current read_pages() assume ->readpages() frees the passed pages.

This patch free the pages in ->read_pages(), if those were remaining in the
pages_list.  So, readpages() just can ignore the remaining pages in
pages_list.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

mm/readahead.c

@@ -173,6 +173,8 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 
 	if (mapping->a_ops->readpages) {
 		ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
+		/* Clean up the remaining pages */
+		put_pages_list(pages);
 		goto out;
 	}