path_umount(): constify struct path argument

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/internal.h

@@ -86,7 +86,7 @@ extern bool may_mount(void);
 
 int path_mount(const char *dev_name, const struct path *path,
 		const char *type_page, unsigned long flags, void *data_page);
-int path_umount(struct path *path, int flags);
+int path_umount(const struct path *path, int flags);
 
 int show_path(struct seq_file *m, struct dentry *root);
 

fs/namespace.c

@@ -2084,7 +2084,7 @@ static int can_umount(const struct path *path, int flags)
 }
 
 // caller is responsible for flags being sane
-int path_umount(struct path *path, int flags)
+int path_umount(const struct path *path, int flags)
 {
 	struct mount *mnt = real_mount(path->mnt);
 	int ret;