udev-generated /dev/disk/by-path names broken for virtio disks

[bugproxy]

The udev-generated /dev/disk/by-path names for virtio disks are broken on z Systems as they have the format virtio-pci-h.h.hhhh[-partn], where h.h.hhhh is the CCW devno of the virtio device representing the whole disk. Historically, the standard CCW naming was applied, which was ccw-h.h.hhhh[-partn]

---uname output---
Linux ubuntu 4.4.0-36-generic #55-Ubuntu SMP Thu Aug 11 18:05:09 UTC 2016 s390x s390x s390x GNU/Linux

Machine Type = 2964-703 running KVM for IBM z Systems

---Debugger---
A debugger is not configured

---Steps to Reproduce---
1. Install Ubuntu LTS 16.04.1 on KVM for IBM z Systems 1.1.1
2. Issue ls -l /dev/disk/by-path

Userspace tool common name: udev

The userspace tool has the following bit modes: 64-bit

Userspace rpm: udev

Userspace tool obtained from project website: na

There are basically two problems with this:
1. The naming is technically incorrect, since the virtio devices on z are no PCI devices but CCW devices
2. Then naming based on virtio- is backwards incompatible. This may seem not to be an issue for Xenial but customers may be confused if they have been running Linux on KVM for IBM z before.

[Dimitri John Ledkov (xnox)]

Userspace rpm: udev
... Ubuntu does not use RPMs, do you mean .deb or just package?

Note the bugs are tracked by source package name, which is systemd.

This change was introduced upstream in v229 see:
https://github.com/systemd/systemd/blob/master/NEWS

https://github.com/systemd/systemd/commit/f073b1b3c0f4f0df1b0bd61042ce85fb5d27d407

https://lists.linuxfoundation.org/pipermail/virtualization/2015-August/030328.html

https://github.com/systemd/systemd/issues/2501

Please discuss this upstream to change/improve the path_id detection. This is not ubuntu-specific and affects all Linux on z that use systemd v229 or newer.

If a fix for this lands upstream, we can discuss cherrypicking it to xenial.

[Dimitri John Ledkov (xnox)]

Hi,
this bug report is marked invalid in Ubuntu, and severity-high has no affect.

Please report this issue upstream at https://github.com/systemd/systemd as it affects all Linux on z distributions (or will when they upgrade to the relevant systemd version)..

Do you have a url to a github issue you have opened?

Regards,

Dimitri.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2017-03-02 04:56 EDT-------
The upstream commit [1] fixes the issue for virtio-ccw and will retain the compatibility symlinks for virtio-pci devices. The commit applies to systemd-229 and later versions.

[1] https://github.com/systemd/systemd/commit/fb92fbb1b171ef94207a1ebc111ef0e414d49b4c

[Dimitri John Ledkov (xnox)]

Thanks! Targeting for this month.

[Dimitri John Ledkov (xnox)]

Was not mentioned in debian/changelog but this is part of v233 release and thus is fix released in artful, and is present in the below mentioned uploads:
ubuntu/233-5ubuntu1
ubuntu/233-6ubuntu1
ubuntu/233-6ubuntu2
ubuntu/233-6ubuntu3
ubuntu/233-8ubuntu1
ubuntu/233-8ubuntu2

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2017-11-16 11:01 EDT-------
IBM Bugzilla Status-> closed. fixed with systemd 233 which is included with Ubuntu 17.10.