filePathKind

fn filePathKind(t: *Threaded, dir: Dir, sub_path: []const u8) !File.Kind {
    if (native_os == .linux) {
        var path_buffer: [posix.PATH_MAX]u8 = undefined;
        const sub_path_posix = try pathToPosix(sub_path, &path_buffer);

        const linux = std.os.linux;
        const syscall: Syscall = try .start();
        while (true) {
            var statx = std.mem.zeroes(linux.Statx);
            switch (linux.errno(linux.statx(
                dir.handle,
                sub_path_posix,
                linux.AT.NO_AUTOMOUNT | linux.AT.SYMLINK_NOFOLLOW,
                .{ .TYPE = true },
                &statx,
            ))) {
                .SUCCESS => {
                    syscall.finish();
                    if (!statx.mask.TYPE) return error.Unexpected;
                    return statxKind(statx.mode);
                },
                .INTR => {
                    try syscall.checkCancel();
                    continue;
                },
                .NOMEM => return syscall.fail(error.SystemResources),
                else => |err| return syscall.unexpectedErrno(err),
            }
        }
    }

    const stat = try dirStatFile(t, dir, sub_path, .{ .follow_symlinks = false });
    return stat.kind;
}