From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from mout.gmx.net ([212.227.17.22]:55288 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030661AbaDJNQd convert rfc822-to-8bit (ORCPT ); Thu, 10 Apr 2014 09:16:33 -0400 From: Ruediger Meier To: Karel Zak Subject: Re: [PATCH] fstrim: add systemd units Date: Thu, 10 Apr 2014 15:16:26 +0200 Cc: "Theodore Ts'o" , Markus Trippelsdorf , util-linux@vger.kernel.org References: <1396561311-12825-1-git-send-email-thomas@archlinux.org> <201404101117.05565.sweet_f_a@gmx.de> <20140410124914.GB26252@x2.net.home> In-Reply-To: <20140410124914.GB26252@x2.net.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Message-Id: <201404101516.26942.sweet_f_a@gmx.de> Sender: util-linux-owner@vger.kernel.org List-ID: On Thursday 10 April 2014, Karel Zak wrote: > On Thu, Apr 10, 2014 at 11:17:04AM +0200, Ruediger Meier wrote: > > Thanks, maybe we could add another minor change to "fstrim -a" > > itself. If possible it would be IMO useful to skip bind mounts to > > avoid trimming the same filesystem several times in a row like > > this: > > > > $ grep "tmp" /etc/fstab > > /dev/vg0/tmpdirs /mnt/tmpdirs ext4 acl,user_xattr 1 > > 2 /mnt/tmpdirs/tmp /tmp none bind > > 0 0 /mnt/tmpdirs/var/tmp /var/tmp none bind > > 0 0 > > > > $ ./fstrim -av > > /tmp: 392 KiB (401408 bytes) trimmed > > /var/tmp: 0 B (0 bytes) trimmed > > /mnt/tmpdirs: 0 B (0 bytes) trimmed > > > > Skipping bind mounts should still trim all mounted filesytems. > > Good idea point, but what about systems where the original > mountpoint is umounted? > > /dev/sda1 /foo ext4 default > /foo /bar none bind > > # mount /foo > # mount /bar > # umount /foo Nice, I thought that wouldn't be even possible to do. > the another story is that we use /proc/self/mountinfo where is > nothing about "bind". It would be probably better to de-duplicate the > list of the filesystems according to filesystem UUID or so. > > I'll think about it. Maybe you could borrow the filter from lsblk. With my fstab above it seems to skip the bind mounts: NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 232.9G 0 disk ├─sda1 8:1 0 512M 0 part /boot └─sda2 8:2 0 232.4G 0 part ├─vg0-root 253:0 0 24G 0 lvm / ├─vg0-swap 253:1 0 4G 0 lvm [SWAP] └─vg0-tmpdirs 253:2 0 204.4G 0 lvm /mnt/tmpdirs > Note all this is probably no problema for ext4 where according to > Lukas is optimization to not call device trim command when there is > nothing to trim. Yes, but maybe nice if we could avoid this anyway. Who know what happens exactly when there is already a heavy load queue and we want to place in several trims. cu, Rudi