[libvirt] [RFC PATCH 2/2] qemu: Force capabilities cache read if libvirtd date is different

Ján Tomko jtomko at redhat.com
Thu May 21 08:59:32 UTC 2015

On Wed, May 20, 2015 at 01:35:43PM -0400, John Ferlan wrote:
> On 05/20/2015 10:22 AM, Ján Tomko wrote:
> > s/read/refresh/ in the commit message?
> > 
> > On Wed, May 20, 2015 at 08:52:57AM -0400, John Ferlan wrote:
> >> https://bugzilla.redhat.com/show_bug.cgi?id=1195882
> >>
> >> Original commit id 'cbde3589' indicates that the cache file would be
> >> discarded if either the QEMU binary or libvirtd 'ctime' changes; however,
> >> the code only discarded if the QEMU binary time didn't match or if the
> >> new libvirtd ctime was later than what created the cache file.
> >>
> >> This could lead to issues with respect to how the order of libvirtd images
> >> is created for maintenance or patch branches where if someone had a libvirtd
> >> created on 'date x' that was created from (a) backported patch(es) followed
> >> by a subsequent install of the primary release which would have 'date y'
> >> where if 'date x' was greater than 'date y', then features in a primary
> >> release branch may not be available.
> > 
> > I can see how here can be two daemons with different ctimes on the same
> > system during development, so ACK to the change.
> But they'd use different cache paths, right?

For privileged daemons, this depends on the LOCALSTATEDIR constant,
which can be chosen at configure time.
For non-privileged, it depends on the XDG_CACHE_HOME environment variable.

I use ./autogen.sh --system for both my libvirt repos, so both store the
cache under /var/

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20150521/8ad31b08/attachment-0001.sig>

More information about the libvir-list mailing list