Re: [PATCH v5 08/13] rewrite reset_crashkernel to support fadump and to used by RPM scriptlet

Rewrite kdumpctl reset-crashkernel KERNEL_PATH as kdumpctl reset-crashkernel [--fadump=[on|off|nocma]] [--kernel=path_to_kernel] [--reboot] This interface would reset a specific kernel to the default crashkernel value given the kernel path. And it also supports grubby's syntax so there are the following special cases, - if --kernel not specified, - use KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump - otherwise use current running kernel, i.e. `uname -r` - if --kernel=DEFAULT, the default boot kernel is chosen - if --kernel=ALL, all kernels would have its crashkernel reset to the default value and the /etc/default/grub is updated as well --fadump=[on|off|nocma] toggles fadump on/off for the kernel provided in KERNEL_PATH. If --fadump is omitted, the dump mode is determined by parsing the kernel command line for the kernel(s) to update. CoreOS/Atomic/Silverblue needs to be treated as a special case because, - "rpm-ostree kargs" is used to manage kernel command line parameters so --kernel doesn't make sense and there is no need to find current running kernel - "rpm-ostree kargs" itself would prompt the user to reboot the system after modify the kernel command line parameter - POWER is not supported so we can assume the dump mode is always kdump This interface will also be called by kexec-tools RPM scriptlets [1] to reset crashkernel. Note the support of crashkenrel.default is dropped. [1] https://docs.fedoraproject.org/en-US/packaging-guidelines/Scriptlets/ Reviewed-by: Pingfan Liu <piliu(a)redhat.com&gt; Signed-off-by: Coiby Xu <coxu(a)redhat.com&gt; --- kdumpctl | 201 +++++++++++++++++++++++++++++++++++++++++++++++------ kdumpctl.8 | 19 +++-- 2 files changed, 191 insertions(+), 29 deletions(-) diff --git a/kdumpctl b/kdumpctl index dd87693..1518e5c 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1355,38 +1355,194 @@ _get_current_running_kernel_path() fi } -reset_crashkernel() +_update_grub() { - local kernel=$1 entry crashkernel_default - local grub_etc_default="/etc/default/grub" + local _kernel_path=$1 _crashkernel=$2 _dump_mode=$3 _fadump_val=$4 - [[ -z $kernel ]] && kernel=$(uname -r) - crashkernel_default=$(cat "/usr/lib/modules/$kernel/crashkernel.default" 2> /dev/null) + if is_atomic; then + if rpm-ostree kargs | grep -q "crashkernel="; then + rpm-ostree kargs --replace="crashkernel=$_crashkernel" + else + rpm-ostree kargs --append="crashkernel=$_crashkernel" + fi + else + [[ -f /etc/zipl.conf ]] && zipl_arg="--zipl" + grubby --args "crashkernel=$_crashkernel" --update-kernel "$_kernel_path" $zipl_arg + if [[ $_dump_mode == kdump ]]; then + grubby --remove-args="fadump" --update-kernel "$_kernel_path" + else + grubby --args="fadump=$_fadump_val" --update-kernel "$_kernel_path" + fi + fi + [[ $zipl_arg ]] && zipl > /dev/null +} - if [[ -z $crashkernel_default ]]; then - derror "$kernel doesn't have a crashkernel.default" - exit 1 +_valid_grubby_kernel_path() +{ + [[ -n "$1" ]] && grubby --info="$1" > /dev/null 2>&1 +} + +_get_all_kernels_from_grubby() +{ + local _kernels _line _kernel_path _grubby_kernel_path=$1 + + for _line in $(grubby --info "$_grubby_kernel_path" | grep "^kernel="); do + _kernel_path=$(_filter_grubby_kernel_str "$_line") + _kernels="$_kernels $_kernel_path" + done + echo -n "$_kernels" +} + +GRUB_ETC_DEFAULT="/etc/default/grub" +# modify the kernel command line parameter in default grub conf +# +# $1: the name of the kernel command line parameter +# $2: new value. If empty, the parameter would be removed +_update_kernel_cmdline_in_grub_etc_default() +{ + local _para=$1 _val=$2 _para_val _regex + + if [[ -n $_val ]]; then + _para_val="$_para=$_val" fi + _regex='^(GRUB_CMDLINE_LINUX=.*)([[:space:]"])'"$_para"'=[^[:space:]"]*(.*)$' + if grep -q -E "$_regex" "$GRUB_ETC_DEFAULT"; then + sed -i -E 's/'"$_regex"'/\1\2'"$_para_val"'\3/' "$GRUB_ETC_DEFAULT" + elif [[ -n $_para_val ]]; then + # If the kernel parameter doesn't exist, put it in the first + sed -i -E 's/^(GRUB_CMDLINE_LINUX=")/\1'"$_para_val"' /' "$GRUB_ETC_DEFAULT" + fi +} + +reset_crashkernel() +{ + local _opt _val _dump_mode _fadump_val _reboot _grubby_kernel_path _kernel _kernels + local _old_crashkernel _new_crashkernel _new_dump_mode _crashkernel_changed + local _new_fadump_val _old_fadump_val _what_is_updated + + for _opt in "$@"; do + case "$_opt" in + --fadump=*) + _val=${_opt#*=} + if _dump_mode=$(get_dump_mode_by_fadump_val $_val); then + _fadump_val=$_val + else + derror "failed to determine dump mode" + exit + fi + ;; + --kernel=*) + _val=${_opt#*=} + if ! _valid_grubby_kernel_path $_val; then + derror "Invalid $_opt, please specify a valid kernel path, ALL or DEFAULT" + exit + fi + _grubby_kernel_path=$_val + ;; + --reboot) + _reboot=yes + ;; + *) + derror "$_opt not recognized" + exit 1 + ;; + esac + done + + # 1. CoreOS uses "rpm-ostree kargs" instead of grubby to manage kernel command + # line. --kernel=ALL doesn't make sense for CoreOS. + # 2. CoreOS doesn't support POWER so the dump mode is always kdump. + # 3. "rpm-ostree kargs" would prompt the user to reboot the system after + # modifying the kernel command line so there is no need for kexec-tools + # to repeat it. if is_atomic; then - if rpm-ostree kargs | grep -q "crashkernel="; then - rpm-ostree kargs --replace="crashkernel=$crashkernel_default" - else - rpm-ostree kargs --append="crashkernel=$crashkernel_default" + _old_crashkernel=$(rpm-ostree kargs | sed -n -E 's/.*(^|\s)crashkernel=(\S*).*/\2/p') + _new_dump_mode=kdump + _new_crashkernel=$(kdump_get_arch_recommend_crashkernel "$_new_dump_mode") + if [[ $_old_crashkernel != "$_new_crashkernel" ]]; then + _update_grub "" "$_new_crashkernel" "$_new_dump_mode" "" + if [[ $_reboot == yes ]]; then + systemctl reboot + fi fi + return + fi + + # For non-ppc64le systems, the dump mode is always kdump since only ppc64le + # has FADump. + if [[ -z $_dump_mode && $(uname -m) != ppc64le ]]; then + _dump_mode=kdump + _fadump_val=off + fi

diff --git a/kdumpctl.8 b/kdumpctl.8 index 74be062..f948709 100644 --- a/kdumpctl.8 +++ b/kdumpctl.8 @@ -50,14 +50,19 @@ Estimate a suitable crashkernel value for current machine. This is a best-effort estimate. It will print a recommanded crashkernel value based on current kdump setup, and list some details of memory usage. .TP -.I reset-crashkernel [KERNEL] -Reset crashkernel value to default value. kdumpctl will try to read -from /usr/lib/modules/<KERNEL>/crashkernel.default and reset specified -kernel's crashkernel cmdline value. If no kernel is -specified, will reset current running kernel's crashkernel value. -If /usr/lib/modules/<KERNEL>/crashkernel.default doesn't exist, will -simply exit return 1. +.I reset-crashkernel [--kernel=path_to_kernel] [--reboot] +Reset crashkernel to default value recommended by kexec-tools. If no kernel +is specified, will reset KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump

+or current running kernel's crashkernel value if KDUMP_KERNELVER is empty. You can +also specify --kernel=ALL and --kernel=DEFAULT which have the same meaning as +grubby's kernel-path=ALL and kernel-path=DEFAULT. ppc64le supports FADump and +supports an additonal [--fadump=[on|off|nocma]] parameter to toggle FADump +on/off.

+Note: The memory requirements for kdump varies heavily depending on the +used hardware and system configuration. Thus the recommended +crashkernel might not work for your specific setup. Please test if +kdump works after resetting the crashkernel value. .SH "SEE ALSO" .BR kdump.conf (5),