Currently kdump use some wrapper around dracut emergency service and emergency shell, this have many problems:
- If dracut-initqueue failed back to emergency mode due to timeout, and faiure action is set to dump_to_rootfs, kdump will try start initqueue again, lead to double timeout error. - Dracut's emergency shell have many builtin actions, like perform dracut emergency_action, ask for root password, generate rdsosreport etc.
This series remove the emergency wrapper, and use a standalone kdump emergency shell. Kdump will always perform final_action after kdump shell, so simplified version works fine.
Update from V1: Fix initqueue status detection in patch 1/3, thanks to Coiby.
Kairui Song (3): Don's try to restart dracut-initqueue if it's already there Remove the kdump error handler isolation wrapper Use a customized emergency shell
dracut-kdump-emergency.service | 25 +++++++++---------- dracut-kdump-error-handler.service | 33 ------------------------ dracut-module-setup.sh | 1 - kdump-lib-initramfs.sh | 40 +++++++++++++++++++++++++----- kexec-tools.spec | 2 -- 5 files changed, 46 insertions(+), 55 deletions(-) delete mode 100644 dracut-kdump-error-handler.service
This reverts commit 7f1f8f229f546818a891400ac7961e485dcd6f3c again. Previous, kdump's dump_to_rootfs tried to detect if initqueue is running and don't start it if it's already running or failed.
But dump_to_rootfs will run after systemd isolate to emergency target, so previous service status are lost, and the detect is invalid always return false.
But now we can remove the isolate wrapper in following commitsa, this detection will be valid and helpful again.
Signed-off-by: Kairui Song kasong@redhat.com --- kdump-lib-initramfs.sh | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh index 5cb0223..eb4b07e 100755 --- a/kdump-lib-initramfs.sh +++ b/kdump-lib-initramfs.sh @@ -218,8 +218,11 @@ save_opalcore_fs() { dump_to_rootfs() {
- dinfo "Trying to bring up rootfs device" - systemctl start dracut-initqueue + if ! ( systemctl is-active dracut-initqueue || systemctl is-failed dracut-initqueue ) &> /dev/null; then + dinfo "Trying to bring up initqueue for rootfs mount" + systemctl start dracut-initqueue + fi + dinfo "Waiting for rootfs mount, will timeout after 90 seconds" systemctl start sysroot.mount
The wrapper is introduced in commit 002337c, according to the commit message, the only usage of the wrapper is when dracut-initqueue calls "systemctl start emergency" directly. In that case, emergency is started, but not in a isolation mode, which means dracut-initqueue is still running. On the other hand, emergency will call "systemctl start dracut-initqueue" again when default action is dump_to_rootfs.
systemd would block on the last dracut-initqueue, waiting for the first instance to exit, which leaves us hang.
In previous commit we added initqueue status detect in dump_to_rootfs, so now even without the wrapper, it will not hang.
And actually, previously, with the wrapper, emergency might still hang for like 30s. When dracut called emergency service because initqueue timed out, dump_to_rootfs will try start initqueue again and timeout again. Now with the wrapper removed, we can avoid these two kinds of hangs, bacause without the isolation we can detect initqueue service status correctly in such case.
Also remove the invalid header comments in service file, the service is not part of systemd code. And sync the service spec with dracut.
Signed-off-by: Kairui Song kasong@redhat.com --- dracut-kdump-emergency.service | 25 +++++++++++----------- dracut-kdump-error-handler.service | 33 ------------------------------ dracut-module-setup.sh | 1 - kexec-tools.spec | 2 -- 4 files changed, 12 insertions(+), 49 deletions(-) delete mode 100644 dracut-kdump-error-handler.service
diff --git a/dracut-kdump-emergency.service b/dracut-kdump-emergency.service index e023284..f2f6fad 100644 --- a/dracut-kdump-emergency.service +++ b/dracut-kdump-emergency.service @@ -1,27 +1,26 @@ -# This file is part of systemd. -# -# systemd is free software; you can redistribute it and/or modify it -# under the terms of the GNU Lesser General Public License as published by -# the Free Software Foundation; either version 2.1 of the License, or -# (at your option) any later version. - -# This service will be placed in kdump initramfs and replace both the systemd -# emergency service and dracut emergency shell. IOW, any emergency will be -# kick this service and in turn isolating to kdump error handler. +# This service will run the real kdump error handler code. Executing the +# failure action configured in kdump.conf
[Unit] -Description=Kdump Emergency +Description=Kdump Error Handler DefaultDependencies=no -IgnoreOnIsolate=yes +After=systemd-vconsole-setup.service +Wants=systemd-vconsole-setup.service
[Service] -ExecStart=/usr/bin/systemctl --no-block isolate kdump-error-handler.service +Environment=HOME=/ +Environment=DRACUT_SYSTEMD=1 +Environment=NEWROOT=/sysroot +WorkingDirectory=/ +ExecStart=/bin/kdump-error-handler.sh +ExecStopPost=-/bin/rm -f -- /.console_lock Type=oneshot StandardInput=tty-force StandardOutput=inherit StandardError=inherit KillMode=process IgnoreSIGPIPE=no +TasksMax=infinity
# Bash ignores SIGTERM, so we send SIGHUP instead, to ensure that bash # terminates cleanly. diff --git a/dracut-kdump-error-handler.service b/dracut-kdump-error-handler.service deleted file mode 100644 index a23b75e..0000000 --- a/dracut-kdump-error-handler.service +++ /dev/null @@ -1,33 +0,0 @@ -# This file is part of systemd. -# -# systemd is free software; you can redistribute it and/or modify it -# under the terms of the GNU Lesser General Public License as published by -# the Free Software Foundation; either version 2.1 of the License, or -# (at your option) any later version. - -# This service will run the real kdump error handler code. Executing the -# failure action configured in kdump.conf - -[Unit] -Description=Kdump Error Handler -DefaultDependencies=no -After=systemd-vconsole-setup.service -Wants=systemd-vconsole-setup.service -AllowIsolate=yes - -[Service] -Environment=HOME=/ -Environment=DRACUT_SYSTEMD=1 -Environment=NEWROOT=/sysroot -WorkingDirectory=/ -ExecStart=/bin/kdump-error-handler.sh -Type=oneshot -StandardInput=tty-force -StandardOutput=inherit -StandardError=inherit -KillMode=process -IgnoreSIGPIPE=no - -# Bash ignores SIGTERM, so we send SIGHUP instead, to ensure that bash -# terminates cleanly. -KillSignal=SIGHUP diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 8316589..b4efc46 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -857,7 +857,6 @@ install() { inst "$moddir/kdump-capture.service" "$systemdsystemunitdir/kdump-capture.service" systemctl -q --root "$initdir" add-wants initrd.target kdump-capture.service inst "$moddir/kdump-error-handler.sh" "/usr/bin/kdump-error-handler.sh" - inst "$moddir/kdump-error-handler.service" "$systemdsystemunitdir/kdump-error-handler.service" # Replace existing emergency service and emergency target cp "$moddir/kdump-emergency.service" "$initdir/$systemdsystemunitdir/emergency.service" cp "$moddir/kdump-emergency.target" "$initdir/$systemdsystemunitdir/emergency.target" diff --git a/kexec-tools.spec b/kexec-tools.spec index 24c6b36..0a6d8e6 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -49,7 +49,6 @@ Source101: dracut-module-setup.sh Source102: dracut-monitor_dd_progress Source103: dracut-kdump-error-handler.sh Source104: dracut-kdump-emergency.service -Source105: dracut-kdump-error-handler.service Source106: dracut-kdump-capture.service Source107: dracut-kdump-emergency.target Source108: dracut-early-kdump.sh @@ -226,7 +225,6 @@ cp %{SOURCE101} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpb cp %{SOURCE102} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE102}} cp %{SOURCE103} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE103}} cp %{SOURCE104} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE104}} -cp %{SOURCE105} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE105}} cp %{SOURCE106} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE106}} cp %{SOURCE107} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE107}} chmod 755 $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE100}}
Use a modified and minimized version of emergency shell. The differences of this kdump shell and dracut emergency shell are:
- Kdump shell won't generate a rdsosreport automatically - Customized prompts - Never ask root password - Won't tangle with dracut's emergency_action. If emergency_action is set, dracut emergency shell will perform dracut's emergency_action instead of kdump final_action on exit. - If rd.shell=no is set, kdump shell will still work, dracut emergency shell won't, even if kdump failure_action is set to shell.
Signed-off-by: Kairui Song kasong@redhat.com --- kdump-lib-initramfs.sh | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh index eb4b07e..cd2227b 100755 --- a/kdump-lib-initramfs.sh +++ b/kdump-lib-initramfs.sh @@ -233,10 +233,35 @@ dump_to_rootfs()
kdump_emergency_shell() { - echo "PS1="kdump:\${PWD}# "" >/etc/profile - ddebug "Switching to dracut emergency..." - /bin/dracut-emergency - rm -f /etc/profile + ddebug "Switching to kdump emergency shell..." + + [ -f /etc/profile ] && . /etc/profile + export PS1='kdump:\${PWD}# ' + + . /lib/dracut-lib.sh + if [ -f /dracut-state.sh ]; then + . /dracut-state.sh 2>/dev/null + fi + + source_conf /etc/conf.d + + type plymouth >/dev/null 2>&1 && plymouth quit + + source_hook "emergency" + while read _tty rest; do + ( + echo + echo + echo 'Entering kdump emergency mode.' + echo 'Type "journalctl" to view system logs.' + echo 'Type "rdsosreport" to generate a sosreport, you can then' + echo 'save it elsewhere and attach it to a bug report.' + echo + echo + ) > /dev/$_tty + done < /proc/consoles + sh -i -l + /bin/rm -f -- /.console_lock }
do_failure_action()
On Wed, Apr 07, 2021 at 03:55:26PM +0800, Kairui Song wrote:
Use a modified and minimized version of emergency shell. The differences of this kdump shell and dracut emergency shell are:
- Kdump shell won't generate a rdsosreport automatically
- Customized prompts
- Never ask root password
- Won't tangle with dracut's emergency_action. If emergency_action is set, dracut emergency shell will perform dracut's emergency_action instead of kdump final_action on exit.
- If rd.shell=no is set, kdump shell will still work, dracut emergency shell won't, even if kdump failure_action is set to shell.
Signed-off-by: Kairui Song kasong@redhat.com
kdump-lib-initramfs.sh | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh index eb4b07e..cd2227b 100755 --- a/kdump-lib-initramfs.sh +++ b/kdump-lib-initramfs.sh @@ -233,10 +233,35 @@ dump_to_rootfs()
kdump_emergency_shell() {
- echo "PS1="kdump:\${PWD}# "" >/etc/profile
- ddebug "Switching to dracut emergency..."
- /bin/dracut-emergency
- rm -f /etc/profile
- ddebug "Switching to kdump emergency shell..."
- [ -f /etc/profile ] && . /etc/profile
- export PS1='kdump:\${PWD}# '
You forgot to fix the unneeded escaping :)
- . /lib/dracut-lib.sh
- if [ -f /dracut-state.sh ]; then
. /dracut-state.sh 2>/dev/null- fi
- source_conf /etc/conf.d
- type plymouth >/dev/null 2>&1 && plymouth quit
- source_hook "emergency"
- while read _tty rest; do
(echoechoecho 'Entering kdump emergency mode.'echo 'Type "journalctl" to view system logs.'echo 'Type "rdsosreport" to generate a sosreport, you can then'echo 'save it elsewhere and attach it to a bug report.'echoecho) > /dev/$_tty- done < /proc/consoles
- sh -i -l
- /bin/rm -f -- /.console_lock
}
do_failure_action()
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On Wed, Apr 7, 2021 at 7:34 PM Coiby Xu coxu@redhat.com wrote:
On Wed, Apr 07, 2021 at 03:55:26PM +0800, Kairui Song wrote:
Use a modified and minimized version of emergency shell. The differences of this kdump shell and dracut emergency shell are:
- Kdump shell won't generate a rdsosreport automatically
- Customized prompts
- Never ask root password
- Won't tangle with dracut's emergency_action. If emergency_action is set, dracut emergency shell will perform dracut's emergency_action instead of kdump final_action on exit.
- If rd.shell=no is set, kdump shell will still work, dracut emergency shell won't, even if kdump failure_action is set to shell.
Signed-off-by: Kairui Song kasong@redhat.com
kdump-lib-initramfs.sh | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh index eb4b07e..cd2227b 100755 --- a/kdump-lib-initramfs.sh +++ b/kdump-lib-initramfs.sh @@ -233,10 +233,35 @@ dump_to_rootfs()
kdump_emergency_shell() {
- echo "PS1="kdump:\${PWD}# "" >/etc/profile
- ddebug "Switching to dracut emergency..."
- /bin/dracut-emergency
- rm -f /etc/profile
- ddebug "Switching to kdump emergency shell..."
- [ -f /etc/profile ] && . /etc/profile
- export PS1='kdump:\${PWD}# '
You forgot to fix the unneeded escaping :)
Oops, thanks for the info, I'll fix it in V3.
-
Coiby Xu -
Kairui Song