[Bug 2065848] Re: An ocf:heartbeat:nfsserver resource's stop operation succeeded despite the /var/lib/nfs filesystem failing to unmount.

[Athos Ribeiro]

I verified this in a lxd VM using the test plan described above after
replacing the kernel as described in "other info".

These are the results I got:


for resource-agents 1:4.7.0-1ubuntu7.2:
Operation force-stop for nfs-daemon (ocf:heartbeat:nfsserver) returned 0 (ok)

for resource-agents 1:4.7.0-1ubuntu7.3 from the proposed pocket:
Operation force-stop for nfs-daemon (ocf:heartbeat:nfsserver) returned 1 (error: Failed to unmount a bind mount)

As expected.

** Tags removed: verification-needed verification-needed-jammy
** Tags added: verification-done verification-done-jammy

** Tags removed: server-todo
** Tags added: server-triage-discuss

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https://bugs.launchpad.net/bugs/2065848

Title:
  An ocf:heartbeat:nfsserver resource's stop operation succeeded despite
  the /var/lib/nfs filesystem failing to unmount.

Status in nfs-utils package in Ubuntu:
  New
Status in resource-agents package in Ubuntu:
  Fix Released
Status in resource-agents source package in Jammy:
  Fix Committed

Bug description:
  [ Impact ]

  the nfsserver resource agent unmounts /var/lib/nfs as part of its stop
  process. WHen such unmount operation fails and re rest of the stop
  operation succeeds, the whole stop operation is reported as being
  successful. However, it should fail in such cases, otherwise, this may
  hider recovery of other resources.

  [ Test Plan ]

  Install the relevant packages:

  # apt update && apt install -y pacemaker corosync resource-agents nfs-
  kernel-server pcs

  Disable STONITH:

  # crm configure property stonith-enabled=false

  Create an ocf:heartbeat:nfsserver resource with a nfs_shared_infodir:

  # pcs resource create nfs-daemon ocf:heartbeat:nfsserver
  nfs_shared_infodir=/mnt/nfs_shared_infodir

  Hold open /var/lib/nfs:

  # touch /var/lib/nfs/testfile
  # exec 3>/var/lib/nfs/testfile

  Stop the resource:

  # pcs resource debug-stop nfs-daemon

  Affected systems should report success when stopping the resource:

  Operation stop for nfs-daemon (ocf:heartbeat:nfsserver) returned: 'ok'
  (0)

  Fixed systems should fail to stop the resource:

  Operation force-stop for nfs-daemon (ocf:heartbeat:nfsserver) returned
  1 (error: Failed to unmount a bind mount)

  [ Where problems could occur ]

  This change consists in having the nfs resource agent to return an
  error in case specific mounts are not unmounted upon stopping the
  agent. If any user custom workflows (erroneously) rely in such
  behavior (having the stop action to succeed even when unmounting
  fails), then this will break such workflow. In this specific case, we
  should just point those users to this bug.

  [ Other Info ]

  This bug was originally reported (and fixed upstream) through
  https://bugzilla.redhat.com/show_bug.cgi?id=1924363. The upstream fix
  is available at https://github.com/ClusterLabs/resource-
  agents/commit/dc4fc6fb51481e62c763212129e7dbae4cb663fd.

  If you want to help with verification, note that the default -kvm
  kernel in Ubuntu lxd VMs has no support for nfs. Therefore, you want
  to install the generic kernel image:

  apt install -y linux-image-generic-hwe-22.04

  and restart the VM.

  [ Original message ]

  The resource "ocf:heartbeat:nfsserver" is considered stopped even the process returned an error:
  pacemaker-execd[7831]:  notice: nfs_daemon_stop_0[65992] error output [ umount: /var/lib/nfs: target is busy. ]

  Beacause it is considered successfully stopped a later unmount of an LVM resource failed:
   LVM-activate(LVM_nfs_infodir_LV)[69671]: ERROR:  PARTIAL MODE. Incomplete logical volumes will be processed. Logical volume DCSS_VG/nfs_infodir contains a filesystem in use.

  cat /etc/lsb-release
  DISTRIB_ID=Ubuntu
  DISTRIB_RELEASE=22.04
  DISTRIB_CODENAME=jammy
  DISTRIB_DESCRIPTION="Ubuntu 22.04.4 LTS"

  resource-agents-base/jammy-updates,now 1:4.7.0-1ubuntu7.2 all [installed,automatic]
    Cluster Resource Agents curated by Ubuntu

  resource-agents-common/jammy-updates,now 1:4.7.0-1ubuntu7.2 amd64 [installed,automatic]
    Common files used by the Cluster Resource Agents

  resource-agents-extra/jammy-updates,now 1:4.7.0-1ubuntu7.2 amd64 [installed]
    Cluster Resource Agents

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