On 04/17/2014 07:43 AM, Laine Stump wrote:
For some reason these have been stored in /var/lib, although other drivers (e.g. qemu and lxc) store their state files in /var/run.
It's much nicer to store state files in /var/run because it is automatically cleared out when the system reboots. We can then use existence of the state file as a convenient indicator of whether or not a particular network is active.
Since changing the location of the state files by itself will cause problems in the case of a *live* upgrade from an older libvirt that uses /var/lib (because current status of active networks will be lost), the network driver initialization has been modified to migrate any network state files from /var/lib to /var/run.
This will not help those trying to *downgrade*, but in practice this will only be problematic in two cases
1) If there are networks with network-wide bandwidth limits configured *and in use* by a guest during a downgrade to "old" libvirt. In this case, the class ID's used for that network's tc rules, as well as the currently in-use bandwidth "floor" will be forgotten.
2) If someone does this: 1) upgrade libvirt, 2) downgrade libvirt, 3) modify running state of network (e.g. add a static dhcp host, etc), 4) upgrade. In this case, the modifications to the running network will be lost (but not any persistent changes to the network's config). --- change from V1:
* merged previous 2/5 & 3/5 into a single patch that changes the location and migrates old state files, to avoid potential problems by people trying to use git bisect.
* move the files with a direct copy, rather than reading/parsing the XML then formatting/writing it. Note (hopefully) correct use of readdir!
* put the migration into a separate static function
* don't put oldStateDir in driverState, as we only use it once during initialization.
* only attempt migration when running privileged, since the unprivileged state location hasn't changed.
src/network/bridge_driver.c | 97 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 91 insertions(+), 6 deletions(-)
ACK; however... Your call if you want to wait for virDirRead() from: http://www.redhat.com/archives/libvir-list/2014-April/msg00745.html Then refactor your for (;;) loop to use it... I'm "assuming" the files cannot be adjusted during the period when libvirt is "migrating" by any other "legal" :-) means. Just typing "out loud" since your v1 would lock the network object and save the status in the new location. John