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https://github.com/ibm-s390-linux/s390-tools.git
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73c46a3056
This prevents out-of-memory (OOM) situations in the kdump crashkernel environment. Please note that the new dracut module 95zdev-kdump and the new library zdev-lib.sh need to be packaged into the same (core) (sub)package as 95zdev. This patch introduces a new dracut module "zdev-kdump", which is used instead of module "zdev" when building a kdump initrd: 1. Ignore all persistently configured block devices and disable zfcp auto LUN scanning => minimize the number of SCSI devices enabled during kdump. 2. Do not rely on chzdev's persistent configuration => work with systems that do not use chzdev for persistent device configuration. The detection of kdump is based on strict hostonly mode and on $IN_KDUMP. See also https://src.fedoraproject.org/rpms/kexec-tools commit 4eedcae5e154 ("dracut-module-setup.sh: don't include multipath-hostonly") and https://github.com/dracutdevs/dracut commits 35e86ac117ac ("Merge 90-multipath-hostonly and 90-multipath") a695250ec7db ("Introduce tri-state hostonly mode") and https://src.fedoraproject.org/rpms/kexec-tools/blob/rawhide/f/mkdumprd#_17 https://src.fedoraproject.org/rpms/kexec-tools/blob/rawhide/f/dracut-module-setup.sh#_23. The detection of kdump is also based on kdump_needed() in https://github.com/openSUSE/kdump/blob/master/dracut/module-setup.sh. Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
100 lines
3.1 KiB
Bash
Executable File
100 lines
3.1 KiB
Bash
Executable File
#!/bin/bash
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#
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# Copyright IBM Corp. 2023
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#
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# s390-tools is free software; you can redistribute it and/or modify
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# it under the terms of the MIT license. See LICENSE for details.
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#
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#
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# 95zdev-kdump/module_setup.sh
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# This module installs configuration files (udev rules and modprobe.conf
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# files) required to enable the kdump target on s390.
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#
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# called by dracut
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check() {
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local _arch=${DRACUT_ARCH:-$(uname -m)}
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# Ensure that we're running on s390
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[ "$_arch" = "s390" -o "$_arch" = "s390x" ] || return 1
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source "$moddir/../95zdev/zdev-lib.sh"
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# Ensure this module is only included when building kdump initrd
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is_kdump || return 1
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# Ensure that required tools are available
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require_binaries chzdev || return 1
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return 0
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}
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# called by dracut
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depends() {
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return 0
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}
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# called by dracut
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installkernel() {
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# Add modules for all device types supported by chzdev (required for
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# auto-configuration)
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instmods ctcm lcs qeth qeth_l2 qeth_l3 dasd_mod dasd_eckd_mod dasd_fba_mod \
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dasd_diag_mod zfcp
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}
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# called by dracut
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install() {
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local _tempfile
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# Obtain kdump target device configuration
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_tempfile=$(mktemp --tmpdir dracut-zdev.XXXXXX)
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# work with systems that are not based on chzdev persistent config
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local _configuration="--active"
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# disable zfcp auto LUN scan to prevent OOM situations on systems with
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# many zFCP LUNs
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inst_dir /etc/modprobe.d
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chzdev zfcp --type "allow_lun_scan=0" --persistent \
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--base "/etc=$initdir/etc" --yes --quiet --no-root-update \
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--force >/dev/null
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# drop /etc/zfcp.conf from dracut module 95zfcp
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echo "rd.zfcp.conf=0" > "$initdir/etc/cmdline.d/00-no-zfcp-conf.conf"
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# => only activate individual zfcp paths found as required below
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function check_zdev() {
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local _dev=$1
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local _devsysfs _bdevpath
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_devsysfs=$(
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cd -P /sys/dev/block/"$_dev" && echo "$PWD"
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)
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_bdevpath=/dev/${_devsysfs##*/}
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# do not export device type information potentially unknown on import
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chzdev --export - "$_configuration" --by-node "$_bdevpath" --quiet \
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2>/dev/null >> "$_tempfile"
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}
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for_each_host_dev_and_slaves_all check_zdev
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sed -i -e 's/^\[active /\[persistent /' "$_tempfile"
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# Apply via --import to prevent other devices from being configured
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chzdev --import "$_tempfile" --persistent --base "/etc=$initdir/etc" \
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--yes --quiet --no-root-update --force >/dev/null
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rm -f "$_tempfile"
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# these are purely generated udev rules so we have to glob expand
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# within $initdir and strip the $initdir prefix for mark_hostonly
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local -a _array
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local _nullglob=$(shopt -p nullglob)
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shopt -u nullglob
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readarray -t _array < \
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<(ls -1 $initdir/etc/udev/rules.d/41-*.rules 2> /dev/null)
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[[ ${#_array[@]} -gt 0 ]] && mark_hostonly "${_array[@]#$initdir}"
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readarray -t _array < \
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<(ls -1 $initdir/etc/modprobe.d/s390x-*.conf 2> /dev/null)
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[[ ${#_array[@]} -gt 0 ]] && mark_hostonly "${_array[@]#$initdir}"
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$_nullglob
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return 0
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}
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