From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 108D9C43381 for ; Tue, 19 Mar 2019 10:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8A0F20828 for ; Tue, 19 Mar 2019 10:58:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbfCSK6b (ORCPT ); Tue, 19 Mar 2019 06:58:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44690 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726782AbfCSK6b (ORCPT ); Tue, 19 Mar 2019 06:58:31 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D0DC33082B0F; Tue, 19 Mar 2019 10:58:30 +0000 (UTC) Received: from work (ovpn-204-238.brq.redhat.com [10.40.204.238]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 321815D70D; Tue, 19 Mar 2019 10:58:28 +0000 (UTC) Date: Tue, 19 Mar 2019 11:58:24 +0100 From: Lukas Czerner To: "Darrick J. Wong" Cc: Theodore Ts'o , linux-ext4@vger.kernel.org, Paul Menzel Subject: Re: [PATCH] e2scrub_all: refactor device probe loop Message-ID: <20190319105824.apzsygxgl5dt3fq6@work> References: <20190319001732.GB4916@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190319001732.GB4916@magnolia> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Tue, 19 Mar 2019 10:58:30 +0000 (UTC) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Mar 18, 2019 at 05:17:32PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Paul Menzel reported that the e2scrub_all reaper service that runs at > startup takes a long time to run, and Ted T'so pointed out that we could > do a lot less work by using lvs as the outer loop in the ext4 filesystem > probe function so that we only have to lsblk the lvm devices containing > ext4 filesystems. > > Therefore, refactor the loops to put lvs first, which should boost speed > a bit. > > Reported-by: Paul Menzel > Signed-off-by: Darrick J. Wong > --- > scrub/e2scrub_all.in | 51 ++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 37 insertions(+), 14 deletions(-) > > diff --git a/scrub/e2scrub_all.in b/scrub/e2scrub_all.in > index 23d122d25..41420d03d 100644 > --- a/scrub/e2scrub_all.in > +++ b/scrub/e2scrub_all.in > @@ -19,6 +19,7 @@ > # Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. > > scrub_all=0 > +reap=0 > conffile="@root_sysconfdir@/e2scrub.conf" > > test -f "${conffile}" && . "${conffile}" > @@ -61,7 +62,7 @@ exitcode() { > while getopts "ArV" opt; do > case "${opt}" in > "A") scrub_all=1;; > - "r") scrub_args="${scrub_args} -r";; > + "r") scrub_args="${scrub_args} -r"; reap=1;; > "V") print_version; exitcode 0;; > *) print_help; exitcode 2;; > esac > @@ -69,27 +70,27 @@ done > shift "$((OPTIND - 1))" > > # Find scrub targets, make sure we only do this once. > -ls_scrub_targets() { > - lsblk -o NAME,FSTYPE,MOUNTPOINT -p -P -n | while read vars; do > +ls_scan_targets() { > + lvs --name-prefixes -o vg_name,lv_name,lv_path \ > + -S lv_active=active,lv_role=public --noheadings | \ You're not using vg_name, nor lv_name so you can drop it maybe ? Also you're missing lv_role since you're checking it later, however you can do this instead -S lv_active=active,lv_role=public -S lv_role!=snapshot so you only need to ask for lv_path > + while read vars; do > eval "${vars}" > + eval "$(lsblk -o NAME,FSTYPE,MOUNTPOINT -p -P -n "${LVM2_LV_PATH}")" Now that you only have one lv filed you can maybe pass this directly to the lsblk ? This looks funny but works fine for me :) lsblk -o MOUNTPOINT,NAME,FSTYPE -p -n `lvs -o lv_path -S lv_active=active,lv_role=public -S lv_role!=snapshot --noheadings` | grep 'ext[234]' | awk '{print $1}' if you only want mounted file systems than you just add | grep -v -E '^/dev/' > > - # Skip non-ext[234] > + # Skip unless ext* > case "${FSTYPE}" in > - ext[234]) ;; > - *) continue;; > + ext*) ;; > + *) continue;; > esac > > + # Don't run against a snapshot ever > + echo "${LVM2_LV_ROLE}" | grep -q "snapshot" && continue > + > # Skip unmounted filesystems unless -A > if [ "${scrub_all}" -eq 0 ] && [ -z "${MOUNTPOINT}" ]; then > continue; > fi > > - # Skip non-lvm devices and lvm snapshots > - lvm_vars="$(lvs --nameprefixes -o vg_name,lv_name,lv_role --noheadings "${NAME}" 2> /dev/null)" > - test $? -ne 0 && continue > - eval "${lvm_vars}" > - echo "${LVM2_LV_ROLE}" | grep -q "snapshot" && continue > - > if [ -n "${MOUNTPOINT}" ]; then > echo "${MOUNTPOINT}" > else > @@ -98,6 +99,28 @@ ls_scrub_targets() { > done | sort | uniq > } > > +# Find leftover scrub snapshots > +ls_reap_targets() { > + lvs --name-prefixes -o vg_name,lv_name,lv_path,origin \ You only seem to be using lv_name and lv_path ? also I think you can do this: lvs -o lv_path -S lv_role=snapshot -S lv_name=~\(e2scrub$\) --noheadings Also since you only ask for one field I tihnk it's already sorted so no need to sort, or add -O -Lukas > + -S lv_role=snapshot --noheadings | while read vars; do > + eval "${vars}" > + > + # Filter out anything except our snapshots > + case "${LVM2_LV_NAME}" in > + *.e2scrub) echo "${LVM2_LV_PATH}";; > + esac > + done | sort | uniq > +} > + > +# Figure out what we're targeting > +ls_targets() { > + if [ "${reap}" -eq 1 ]; then > + ls_reap_targets > + else > + ls_scan_targets > + fi > +} > + > # systemd doesn't know to do path escaping on the instance variable we pass > # to the e2scrub service, which breaks things if there is a dash in the path > # name. Therefore, do the path escaping ourselves if needed. > @@ -118,10 +141,10 @@ escape_path_for_systemd() { > > # Scrub any mounted fs on lvm by creating a snapshot and fscking that. > stdin="$(realpath /dev/stdin)" > -ls_scrub_targets | while read tgt; do > +ls_targets | while read tgt; do > # If we're not reaping and systemd is present, try invoking the > # systemd service. > - if [ -z "${scrub_args}" ] && type systemctl > /dev/null 2>&1; then > + if [ "${reap}" -ne 1 ] && type systemctl > /dev/null 2>&1; then > tgt_esc="$(escape_path_for_systemd "${tgt}")" > ${DBG} systemctl start "e2scrub@${tgt_esc}" 2> /dev/null < "${stdin}" > res=$?