From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759610AbZBZXS0 (ORCPT ); Thu, 26 Feb 2009 18:18:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754572AbZBZXSO (ORCPT ); Thu, 26 Feb 2009 18:18:14 -0500 Received: from mx2.redhat.com ([66.187.237.31]:52306 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758984AbZBZXSN (ORCPT ); Thu, 26 Feb 2009 18:18:13 -0500 Message-ID: <49A7232C.6050808@redhat.com> Date: Thu, 26 Feb 2009 15:18:04 -0800 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Linux Kernel Subject: filesystem time stamp resolution X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 How can code at userlevel (e.g., glibc) determine the resolution of the a filesystem timestamp? Boundary condition: - - I cannot create or modify a file since the information must also be available for filesystems where the caller has no write permission - - it has to work going forward (i.e., hardcoding information is no good idea) One acceptable solution (for me) would be to have directories for the filesystem types under /proc/fs (or /sys/fs) which show this information. E.g.: /proc/fs/ext4/timestamp-resolution Measured in nano-seconds or so. As a bonus have symlinks like /proc/fs/ef53 -> /proc/fs/ext4 (i.e., map the superblock magic number to a name. But I can live with this missing.) As a second bonus any help for network filesystems would be good but. Do I miss anything that is there already? - -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkmnIywACgkQ2ijCOnn/RHRSDgCfUep/fJohBr8kI+iuEFbanL5C oXYAn03tnvPse68ewluvH5qrqJj02AEG =W6ln -----END PGP SIGNATURE-----