Re: [PATCH] qemu: domfsinfo should print a target name on s390x, not a complete device path

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.

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.