Comment 31 for bug 1925211

Testing former status with 5.11.0-17-generic

Journal:
Add:
May 17 05:56:26 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=5
May 17 05:56:26 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0
May 17 05:56:26 h kernel: virtio_blk virtio5: [vdc] 385 512-byte logical blocks (197 kB/193 KiB)
Remove:
May 17 05:56:35 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=5
May 17 05:56:35 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0

ubuntu@s1lp5:~$ virsh attach-disk h /var/lib/libvirt/images/test.qcow2 vdc
Disk attached successfully

ubuntu@s1lp5:~$ virsh detach-disk h vdc
Disk detached successfully

ubuntu@s1lp5:~$ virsh domblklist h
 Target Source
----------------------------------------------------
 vda /var/lib/uvtool/libvirt/images/h.qcow
 vdb /var/lib/uvtool/libvirt/images/h-ds.qcow

ubuntu@s1lp5:~$ uvt-kvm ssh --insecure hirsute-2nd-zfs lsblk
uvt-kvm: error: libvirt: Domain not found: no domain with matching name 'hirsute-2nd-zfs'
ubuntu@s1lp5:~$ uvt-kvm ssh --insecure h lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 47.9M 1 loop /snap/core18/1998
loop1 7:1 0 29.9M 1 loop /snap/snapd/11838
loop2 7:2 0 63.1M 1 loop /snap/lxd/20396
vda 252:0 0 8G 0 disk
└─vda1 252:1 0 8G 0 part /
vdb 252:16 0 372K 0 disk
vdc 252:32 0 192.5K 0 disk

The disk is still present despite not really being in the guest anymore.

Now testing the proposed kernel 5.11.0-18-generic

Upgrades fine, well triggering an unrelated bug 1928625 but fine in regard to the issue here.

Then journal (as expected) looks the same:
# Attach
May 17 06:09:22 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=5
May 17 06:09:22 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0
May 17 06:09:22 h kernel: virtio_blk virtio5: [vdc] 385 512-byte logical blocks (197 kB/193 KiB)
# Detach
May 17 06:09:29 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=5
May 17 06:09:29 h kernel: crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0

But lsblk confirms that the new kernel now works:
ubuntu@s1lp5:~$ virsh attach-disk h /var/lib/libvirt/images/test.qcow2 vdc
Disk attached successfully

ubuntu@s1lp5:~$ virsh detach-disk h vdc
Disk detached successfully

ubuntu@s1lp5:~$ virsh domblklist h
 Target Source
----------------------------------------------------
 vda /var/lib/uvtool/libvirt/images/h.qcow
 vdb /var/lib/uvtool/libvirt/images/h-ds.qcow

ubuntu@s1lp5:~$ uvt-kvm ssh --insecure h lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 63.1M 1 loop /snap/lxd/20396
loop1 7:1 0 29.9M 1 loop /snap/snapd/11838
loop2 7:2 0 47.9M 1 loop /snap/core18/1998
vda 252:0 0 8G 0 disk
└─vda1 252:1 0 8G 0 part /
vdb 252:16 0 372K 0 disk

^^ no more vdc after the detach.
Setting verified