[libvirt] [PATCHv2 7/7] snapshot: implement snapshot children listing in qemu

[Eric Blake]

On 10/09/2011 09:29 PM, Daniel Veillard wrote:
> On Fri, Sep 30, 2011 at 05:09:29PM -0600, Eric Blake wrote:
>> Not too hard to wire up.  The trickiest part is realizing that
>> listing children of a snapshot cannot use SNAPSHOT_LIST_ROOTS,
>> and that we overloaded that bit to also mean SNAPSHOT_LIST_DESCENDANTS;
>> we use that bit to decide which iteration to use, but don't want
>> the existing counting/listing functions to see that bit.
>>

>> +static int
>> +qemuDomainSnapshotNumChildren(virDomainSnapshotPtr snapshot,
>> +                              unsigned int flags)
>> +{
>> +    struct qemud_driver *driver = snapshot->domain->conn->privateData;

>
>    ACK,

I've now pushed 1-7.

> I would tend to be a bit more defensive myself byt not dereferencing 3
> layers of pointer as the first instructions in the function, but
> if you're confident the structures can't be missing :-)

Yes, src/libvirt.c already validated that snapshot, snapshot->domain, 
and snapshot->domain->conn are all correct and non-NULL.  We do this 
same sort of 3-level validation in several other APIs, relying on 
libvirt.c to have filtered out invalid objects in advance of calling the 
hypervisor callback.

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