← Back to team overview

sts-sponsors team mailing list archive

[Bug 1821255] Re: Restart policy "Always" doesn't work under certain circumstances

 

[sponsor note]
- Can you please submit the change to Debian ?
- Does Xenial would need the fix as well as it come with systemd by default and as the 'ExecStop=/sbin/iscsiadm -k 0 2' directive as well ? 

** Changed in: open-iscsi (Ubuntu Disco)
       Status: Confirmed => In Progress

-- 
You received this bug notification because you are a member of STS
Sponsors, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1821255

Title:
  Restart policy "Always" doesn't work under certain circumstances

Status in open-iscsi package in Ubuntu:
  In Progress
Status in open-iscsi source package in Bionic:
  Confirmed
Status in open-iscsi source package in Cosmic:
  Confirmed
Status in open-iscsi source package in Disco:
  In Progress

Bug description:
  [Impact]
  iscsid restart fails when killed with SIGTERM

  [Description]
  If systemd tries to execute a command that talks to iscsid via iscsid.socket, it can hang if iscsid is not running (or is in the process of being stopped). This can happen due to the current ExecStop= directive, which calls iscsiadm to kill iscsid, and prevents the service from being restarted even when we set Restart=always in the iscsid unit file.

  The solution is to let systemd terminate iscsid by itself. The default action
  when omitting the ExecStop directive is to send SIGTERM to the process group,
  which is equivalent to invoking "iscsiadm -k" (the current ExecStop command).

  [Test Case]
  1) Deploy a Disco VM e.g. with uvt-kvm
      $ uvt-kvm create disco release=disco

  2) Run the deploy-tgt.sh script in the VM to setup an iSCSI target in the
  localhost. The script will install tgt and open-iscsi, configure a 1G
  file-backed iSCSI target, login and restart iscsid.service
      ubuntu@disco:~$ ./deploy-tgt.sh

  3) Kill iscsid with SIGTERM
      ubuntu@disco:~$ sudo pkill iscsid

  4) Try to stop iscsid.service and check whether it hangs
      ubuntu@disco:~$ sudo systemctl stop iscsid

  If we remove the ExecStop= directive, it works as expected:
      ubuntu@disco:~$ sudo systemctl stop iscsid
      ubuntu@disco:~$
  This also causes Restart=always to work as expected.

  [Regression Potential]
  This shouldn't introduce any regressions, since iscsiadm -k just sends SIGTERM to iscsid's process group and that's equivalent to the default systemd ExecStop action. Nonetheless, changes will be tested with autopkgtests and different iscsi scenarios.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/open-iscsi/+bug/1821255/+subscriptions