current_chrooted(): use guards

here a use of __free(path_put) for dropping fs_root is enough to
make guard(mount_locked_reader) fit...

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

diff --git a/fs/namespace.c b/fs/namespace.c
index cf680fbf015e9fc856d3e1ca425ecbee0761bf63..0474b3a93dbf2859ae853cd156fad235b10190b3 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -6194,23 +6194,20 @@ bool our_mnt(struct vfsmount *mnt)
 bool current_chrooted(void)
 {
        /* Does the current process have a non-standard root */
-       struct mount *root = current->nsproxy->mnt_ns->root;
-       struct path fs_root;
-       bool chrooted;
+       struct path fs_root __free(path_put) = {};
+       struct mount *root;
 
        get_fs_root(current->fs, &fs_root);
 
        /* Find the namespace root */
-       read_seqlock_excl(&mount_lock);
 
+       guard(mount_locked_reader)();
+
+       root = current->nsproxy->mnt_ns->root;
        while (unlikely(root->overmount))
                root = root->overmount;
 
-       chrooted = fs_root.mnt != &root->mnt || !path_mounted(&fs_root);
-
-       read_sequnlock_excl(&mount_lock);
-       path_put(&fs_root);
-       return chrooted;
+       return fs_root.mnt != &root->mnt || !path_mounted(&fs_root);
 }
 
 static bool mnt_already_visible(struct mnt_namespace *ns,