diff --git a/fs/namespace.c b/fs/namespace.c
index f47d4850bd93d98bc6c157f531c228fb7f7611d5..68e3777b9323e4c6181b1fa0113c31e31dbcc62e 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2547,9 +2547,12 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
 		return -ENODEV;
 
 	mnt = vfs_kern_mount(type, sb_flags, name, data);
-	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
-	    !mnt->mnt_sb->s_subtype)
-		mnt = fs_set_subtype(mnt, fstype);
+	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE)) {
+		down_write(&mnt->mnt_sb->s_umount);
+		if (!mnt->mnt_sb->s_subtype)
+			mnt = fs_set_subtype(mnt, fstype);
+		up_write(&mnt->mnt_sb->s_umount);
+	}
 
 	put_filesystem(type);
 	if (IS_ERR(mnt))