On 03/05/2014 01:40 PM, Guido Günther wrote:
Hi Daniel,
On Wed, Mar 05, 2014 at 05:53:53PM +0000, Daniel P. Berrange wrote:
[..snip..]
> + /* Discard if cache is older that QEMU binary */
> + /* XXX must also compare to libvirtd timestamp */
> + if (sb.st_mtime < qemuCaps->mtime) {
I think looking at the mtime isn't sufficent here. Tools like dpkg set
the mtime to the time the package was built at not the installation time
so we might end up updating qemu but still having an mtime older than
the time the xml was created (same holds for downgrades to older qemu
versions) or are we simply requiring distributors to clean the cache
upon package upgrades (which would mandate using a trigger)?
ctime is better than mtime, because ctime can't be faked. On the other
hand, ctime changes in more situations than mtime (chmod, anyone?) - but
then again, any time ctime changes, we probably DO want to retest (a
chmod may change our ability to execute a given binary).
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org