On 10/03/2014 10:26 AM, Michal Privoznik wrote:
On 03.10.2014 17:03, Eric Blake wrote:
Aeons ago (commit 34dcbbb4, v0.8.2), we added a new libvirt event (VIR_DOMAIN_EVENT_ID_IO_ERROR_REASON) in order to tell the user WHY the guest halted. This is because at least VDSM wants to react differently to ENOSPC events (resize the lvm partition to be larger, and resume the guest as if nothing had happened) from all other events (I/O is hosed, throw up our hands and flag things as broken). At the time this was done, downstream RHEL qemu added a vendor extension '__com.redhat_reason', which would be exactly one of these strings: "enospc", "eperm", "eio", and "eother". In our stupidity, we exposed those exact strings to clients, rather than an enum, and we also return "" if we did not have access to a reason (which was the case for upstream qemu).
Fast forward to now: upstream qemu commit c7c2ff0c (will be qemu 2.2) FINALLY adds a 'nospace' boolean, after discussion with multiple projects determined that VDSM really doesn't care about distinction between any other error types. So this patch converts 'nospace' into the string "enospc" for compatibility with RHEL clients that were already used to the downstream extension, while leaving the reason blank for all other cases (no change from the status quo).
See also https://bugzilla.redhat.com/show_bug.cgi?id=1119784
ACK
Thanks; pushed. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org