dirStatFileLinux

fn dirStatFileLinux(
    userdata: ?*anyopaque,
    dir: Dir,
    sub_path: []const u8,
    options: Dir.StatFileOptions,
) Dir.StatFileError!File.Stat {
    const t: *Threaded = @ptrCast(@alignCast(userdata));
    _ = t;
    const linux = std.os.linux;
    const sys = if (statx_use_c) std.c else std.os.linux;

    var path_buffer: [posix.PATH_MAX]u8 = undefined;
    const sub_path_posix = try pathToPosix(sub_path, &path_buffer);

    const flags: u32 = linux.AT.NO_AUTOMOUNT |
        @as(u32, if (!options.follow_symlinks) linux.AT.SYMLINK_NOFOLLOW else 0);

    const syscall: Syscall = try .start();
    while (true) {
        var statx = std.mem.zeroes(linux.Statx);
        switch (sys.errno(sys.statx(dir.handle, sub_path_posix, flags, linux_statx_request, &statx))) {
            .SUCCESS => {
                syscall.finish();
                return statFromLinux(&statx);
            },
            .INTR => {
                try syscall.checkCancel();
                continue;
            },
            else => |e| {
                syscall.finish();
                switch (e) {
                    .ACCES => return error.AccessDenied,
                    .BADF => |err| return errnoBug(err), // File descriptor used after closed.
                    .FAULT => |err| return errnoBug(err),
                    .INVAL => |err| return errnoBug(err),
                    .LOOP => return error.SymLinkLoop,
                    .NAMETOOLONG => |err| return errnoBug(err), // Handled by pathToPosix() above.
                    .NOENT => return error.FileNotFound,
                    .NOTDIR => return error.NotDir,
                    .NOMEM => return error.SystemResources,
                    else => |err| return posix.unexpectedErrno(err),
                }
            },
        }
    }
}