New subject: [PATCH] Don't execute final_action if failure_action terminates the system

7 Nov 2019

On Tue, Nov 5, 2019 at 8:37 PM d.hatayama@fujitsu.com
d.hatayama@fujitsu.com wrote:
...
...
-----Original Message-----
From: Kairui Song [mailto:kasong@redhat.com]
Sent: Wednesday, October 30, 2019 6:35 PM
To: kexec@lists.fedoraproject.org
Cc: Pingfan Liu piliu@redhat.com; Dave Young dyoung@redhat.com; Hatayama,
Daisuke/畑山 大輔 d.hatayama@fujitsu.com; Kairui Song kasong@redhat.com
Subject: [PATCH] Don't execute final_action if failure_action terminates the
system
If failure_action is shutdown/reboot/halt, final_action is pointless as
the system will be already stopping. And if final_action is different
from failure_action, it will trigger a systemd race problem and cause
unexpected behavior to occur.
So let the error handler stop and exit after performing failure_action
successfully if failure_action is one of shutdown/reboot/halt.
This way, final_action will not be executed.
Signed-off-by: Kairui Song kasong@redhat.com
kdump-lib-initramfs.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh
index c409dce..8530556 100755
--- a/kdump-lib-initramfs.sh
+++ b/kdump-lib-initramfs.sh
@@ -56,13 +56,13 @@ get_kdump_confs()
                         FAILURE_ACTION="kdump_emergency_shell"
                     ;;
                     reboot)

                   FAILURE_ACTION="systemctl reboot -f"




                   FAILURE_ACTION="systemctl reboot -f && exit"



Can -f option here also be removed?
...
                 ;;
                 halt)


                   FAILURE_ACTION="halt"




                   FAILURE_ACTION="halt && exit"



It's better to replace halt with systemctl halt as suggested by Dave.
...
                 ;;
                 poweroff)


                   FAILURE_ACTION="systemctl poweroff -f"




                   FAILURE_ACTION="systemctl poweroff -f && exit"



Ditto.
I also checked the behavior when FAILURE_ACTION="exit" for in case, i.e.
the situation where shutdown/halt/reboot doesn't work well for some reason
even though it terminates with successful exit status.
The result is infinite loop like:
kdump-capture.serviec pulls in emergency.target on failrue
   => emergency.target pulls in emergency.service
   => emergency.service isolates kdump-error-handler.service
   => kdump-error-handler.service isolates default.target (= initrd.target) on ExecStopPost=
   => initrd.target pulls in kdump-capture.service
I think there is a room to improve this design in another work.
Good suggestions.
Maye it's a good idea to let ExecStopPost= repeat the final_action again?
-- 
Best Regards,
Kairui Song

    

Re: [PATCH] Don't execute final_action if failure_action terminates the system

Signed-off-by: Kairui Song kasong@redhat.com

Signed-off-by: Kairui Song kasong@redhat.com