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

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.