diff --git a/fs/namespace.c b/fs/namespace.c
index db51ddc..63ced21 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -936,8 +936,9 @@
 
 /*
  * recursively change the type of the mountpoint.
+ * noinline this do_mount helper to save do_mount stack space.
  */
-static int do_change_type(struct nameidata *nd, int flag)
+static noinline int do_change_type(struct nameidata *nd, int flag)
 {
 	struct vfsmount *m, *mnt = nd->mnt;
 	int recurse = flag & MS_REC;
@@ -960,8 +961,10 @@
 
 /*
  * do loopback mount.
+ * noinline this do_mount helper to save do_mount stack space.
  */
-static int do_loopback(struct nameidata *nd, char *old_name, int recurse)
+static noinline int do_loopback(struct nameidata *nd, char *old_name,
+				int recurse)
 {
 	struct nameidata old_nd;
 	struct vfsmount *mnt = NULL;
@@ -1010,8 +1013,9 @@
  * change filesystem flags. dir should be a physical root of filesystem.
  * If you've mounted a non-root directory somewhere and want to do remount
  * on it - tough luck.
+ * noinline this do_mount helper to save do_mount stack space.
  */
-static int do_remount(struct nameidata *nd, int flags, int mnt_flags,
+static noinline int do_remount(struct nameidata *nd, int flags, int mnt_flags,
 		      void *data)
 {
 	int err;
@@ -1046,7 +1050,10 @@
 	return 0;
 }
 
-static int do_move_mount(struct nameidata *nd, char *old_name)
+/*
+ * noinline this do_mount helper to save do_mount stack space.
+ */
+static noinline int do_move_mount(struct nameidata *nd, char *old_name)
 {
 	struct nameidata old_nd, parent_nd;
 	struct vfsmount *p;
@@ -1121,8 +1128,9 @@
 /*
  * create a new mount for userspace and request it to be added into the
  * namespace's tree
+ * noinline this do_mount helper to save do_mount stack space.
  */
-static int do_new_mount(struct nameidata *nd, char *type, int flags,
+static noinline int do_new_mount(struct nameidata *nd, char *type, int flags,
 			int mnt_flags, char *name, void *data)
 {
 	struct vfsmount *mnt;