At 2017-12-18 21:57:11, "John Ferlan" <jferlan@xxxxxxxxxx> wrote: > > >On 12/15/2017 09:50 PM, Chen Hanxiao wrote: >> >> >> At 2017-12-16 09:26:32, "John Ferlan" <jferlan@xxxxxxxxxx> wrote: >>> >>> >>> On 12/14/2017 06:16 AM, Chen Hanxiao wrote: >>>> From: Chen Hanxiao <chenhanxiao@xxxxxxxxx> >>>> >>>> Some services, such as Nova, check whether device was not found >>>> by errror messages "not found". [1] >>> >>> error >>> >>>> >>>> This patch unify logs of qemuDomainDetachDeviceLive, which will be helpful. >>>> >>>> [1] https://github.com/openstack/nova/blob/master/nova/virt/libvirt/guest.py#L406 >>>> >>>> Signed-off-by: Chen Hanxiao <chenhanxiao@xxxxxxxxx> >>>> --- >>>> src/qemu/qemu_hotplug.c | 18 +++++++++++------- >>>> 1 file changed, 11 insertions(+), 7 deletions(-) >>>> >>> >>> Something about a tool that parses the error message(s) looking for a >>> specific message string in English and needing to alter libvirt sources >>> to match that tools' needs strikes me as incorrect and a "slippery >>> slope" to follow. >>> >>> I'm not in favor of this because we'll be constantly chasing these types >>> of bugs to match some other tools' (what I think is) incorrect means to >>> handle errors. >>> >> >> Agree. >> But we don't have enough error code to cover all of scenario. >> > >Then there'd be a "different" fix required - adding an error code... >Perhaps VIR_ERR_NO_DEVICE which would have error text "device %s not found"? Thanks for the review. I'll post a patch to throw VIR_ERR_NO_DEVICE for hot_plug cases. > >Of course that would require up the stack source code changes as well. >Still better than scanning the error message which only works for a >specific language set. IOW: how would this work for non "English" languages? > >> For qemuDomainDetachDeviceDiskLive, VIR_ERR_OPERATION_FAILED can be >> "disk not found", also can be "cannot hot unplug multifunction PCI device" >> in the following call of qemuDomainDetachVirtioDiskDevice. > >So it's "OK" to have a different operational failure? I assume that'll >cause a failure elsewhere in the code. I didn't go digging on the source >code - just a quick look at the _try_detach_device method from the above >nova link. > >> >> So the tools powered by libvirt had to find a workaround by >> analyzing error messages... > >Again, wouldn't those tools be broken without the right language set >being used? > Thanks for the detail clarification. Checking words in error log is a bad way to catch errors and should be fixed. Regards, - Chen -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
