[libvirt] [PATCHv3 03/43] snapshot: properly revert qemu to offline snapshots

[Eric Blake]

On 08/24/2011 10:10 AM, Daniel P. Berrange wrote:
> On Wed, Aug 24, 2011 at 09:22:20AM -0600, Eric Blake wrote:
>> +{
>> +    const char *qemuimgarg[] = { NULL, "snapshot", "-a", NULL, NULL, NULL };

>> +    for (i = 0; i<  vm->def->ndisks; i++) {

>> +
>> +            qemuimgarg[4] = vm->def->disks[i]->src;
>> +
>> +            if (virRun(qemuimgarg, NULL)<  0)

>
> I know that virRun is implemented in terms of virCommand, but should
> be we aiming to convert virRun uses over to directly use virCommand ?

Here, virRun really is nicer, because it is the only interface that lets 
us modify _just_ qemuimgarg[4] without having to alter the earlier array 
elements.  If we directly used virCommand, we'd have to start from 
scratch each time around, or add a new virCommand interface that would 
let us delete or otherwise modify arguments previously added.  That, and 
this new code was merely copying after other functions that did qemu-img 
snapshot -c and qemu-img snapshot -d for multiple files.

>
> ACK
>
> Daniel

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org