[libvirt] [PATCH] qemu: Add missing VIR_DOMAIN_BLOCK_COMMIT_DELETE flags

Alex Jia ajia at redhat.com
Wed Aug 28 03:26:29 UTC 2013

On 08/27/2013 07:59 PM, Eric Blake wrote:
> On 08/27/2013 03:37 AM, Michal Privoznik wrote:
>>> Yes, the codes haven't any implementation for BLOCK_COMMIT_DELETE flag
>>> now, maybe, only need to raise a friendly error message in here instead
>>> of "unsupported flags (0x2) xxxx".
>> I agree that this error message is not user-friendly. Bare virsh users
>> know nothing about our flags and their numerical expression. However, I
>> don't think there is a way how to produce "Unsupported flag
>> VIR_DOMAIN_BLOCK_COMMIT_DELETE" instead of "Unsupported flag 0x2" since
>> all we see in the qemuDomainBlockCommit() function is just number. I
>> mean, mapping of flag onto numeric value is not one-to-one function (aka
>> injective function). That is, a value 0x2 can express
>> VIR_DUMP_DESTROY, etc. (git grep "1<<  1," include/).
>> If we want to make it work, we have to introduce an injective function,
>> e.g. virUnsupportedFlags(), which would accept a list (not an ORed
>> value) of all flags that are not supported. Too much effort for not much
>> outcome.
> Agreed - it may not be the nicest of messages, but it is a CORRECT
> message, and one that will eventually go away when we actually implement
> things, so it isn't worth the churn of making a temporarily "nicer"
> message just to rip it back out later when things are properly implemented.

Agree, it isn't worth changing a temporarily "nicer" message now.

More information about the libvir-list mailing list