On 13/11/2020 08.21, Peter Krempa wrote: > On Thu, Nov 12, 2020 at 23:48:02 +0100, Thomas Huth wrote: >> While fixing domfsinfo for non-PCI (i.e. CCW) devices on s390x, >> I accidentally used the whole device path for the devAlias field. >> However, it should only contain the base target name. >> >> Currently we have the wrong output: >> >> $ virsh domfsinfo guestname >> Mountpoint Name Type Target >> --------------------------------------- >> / sda3 xfs /dev/sda3 >> /boot sda1 xfs /dev/sda1 >> >> It should look like this instead: >> >> $ virsh domfsinfo guestname >> Mountpoint Name Type Target >> ------------------------------------ >> / sda3 xfs sda >> /boot sda1 xfs sda >> >> Thus we have to strip the "/dev/" prefix and the partition number >> from the string. > > This is not the correct approach. While our "target" looks suspiciously > close to the guest /dev/name it can't be guaranteed to be the same. Ouch, ok, got it now. On x86, I can apparently say: <target dev='vdc' bus='virtio'/> for my first disk of my guest, and domfsinfo then shows up like this: Mountpoint Name Type Target ----------------------------------------------------------- / dm-0 xfs vdc /boot vda1 xfs vdc ... very confusing if you're not used to it ;-) > Stripping prefix and suffix may work in many cases, but if you want to > uphold what's written in the API docs this won't be always correct. > > I think we need to just relax the documentation of 'virsh domfsinfo' and > report the path as we do now if the s390x platform is unable to report > back any information which would allow us to match the device otherwise. Ok, I'll ponder about this for a while - maybe there's a way to fix this on s390x ... otherwise I'll consider sending a patch to update the docs. Thanks, Thomas
