Re: [libvirt] [PATCHv2 08/16] storage: get entire metadata chain in one call

On 10/16/2012 08:43 AM, Laine Stump wrote: Later in the series, I convert virDomainDiskDefForeachPath, which had an argument that said whether to ignore open failures while recursing through a chain. That implies that there are some callers that care about being able to find every file in a chain, while other callers want to know as much as possible but don't care once they can't get further. I debated about how best to represent this in the new recursive data structure, and ended up with: if meta->backingStoreIsFile is set but meta->backingStoreMeta is clear, the recursion failed partway through, and it is up to the caller to decide if an aborted recursion is fatal. I also debated about whether I should have the helper function return an int instead of a pointer; returning a pointer or NULL is a boolean operation, and does not allow for as much flexibility. Returning an int would let me do things like returning 0 if recursion ended normally, returning 1 if recursion ended because a file could not be opened, and returning -1 if recursion ended due to OOM or other fatal problem. If you want me to revise along those lines I can, but for now, I think I'll just change this to be a VIR_WARN instead of a virReportSystemError(). I did that solely to fit within 80 columns. -- Eric Blake eblake(a)redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org