diff --git a/mm/filemap.c b/mm/filemap.c
index d504d6e..4082b3b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2069,7 +2069,7 @@
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space * mapping = file->f_mapping;
-	struct address_space_operations *a_ops = mapping->a_ops;
+	const struct address_space_operations *a_ops = mapping->a_ops;
 	struct inode 	*inode = mapping->host;
 	long		status = 0;
 	struct page	*page;
@@ -2219,7 +2219,7 @@
 				unsigned long nr_segs, loff_t *ppos)
 {
 	struct file *file = iocb->ki_filp;
-	struct address_space * mapping = file->f_mapping;
+	const struct address_space * mapping = file->f_mapping;
 	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	struct inode 	*inode = mapping->host;