From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42140) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bxVmW-0002TF-AM for qemu-devel@nongnu.org; Fri, 21 Oct 2016 05:06:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bxVmT-0001jm-53 for qemu-devel@nongnu.org; Fri, 21 Oct 2016 05:06:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48058) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1bxVmS-0001je-Vz for qemu-devel@nongnu.org; Fri, 21 Oct 2016 05:06:25 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 15425C04B321 for ; Fri, 21 Oct 2016 09:06:24 +0000 (UTC) From: Markus Armbruster References: <20161019101616.GL11194@redhat.com> <87a8e0bkl6.fsf@dusky.pond.sub.org> <20161019122158.GS11194@redhat.com> <20161019180616.GF2035@work-vm> <87oa2fwg9z.fsf@dusky.pond.sub.org> <20161020090356.GD12145@redhat.com> <20161020095835.GC2039@work-vm> <87funrti86.fsf@dusky.pond.sub.org> <20161020110832.GG12145@redhat.com> <87insnqllc.fsf@dusky.pond.sub.org> <20161020175648.GN2039@work-vm> Date: Fri, 21 Oct 2016 11:06:21 +0200 In-Reply-To: <20161020175648.GN2039@work-vm> (David Alan Gilbert's message of "Thu, 20 Oct 2016 18:56:48 +0100") Message-ID: <8760omm5pu.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] chardev's and fd's in monitors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org "Dr. David Alan Gilbert" writes: > * Markus Armbruster (armbru@redhat.com) wrote: >> "Daniel P. Berrange" writes: [...] >> > Realistically all the major backend subsystems (chardev, network, block, >> > ui and migration) need to be converted to Error ** propagation, since >> > they all ultimately call into some common code that reports Error **. >> >> Infrastucture generally doesn't know how it's used, which means >> error_report() is generally wrong there. Sufficiently simple functions >> can keep returning -errno, null, whatever, but the interesting stuff >> needs to use Error. >> > Very few places will end up being able to stick with -errno, or plain >> > error_report in the long term. >> >> Not sure about "very few". Less than now. We'll see. > > I'd also prefer we got the very-few level; Migration used to be > characterised by getting a 'load of migration failed -22' and having > no clue in the logs to why; I've slowly fought back to be able > to get an error from the lowest level that caused the failure. > I want more of that, so that when someone gets a rare failure in the field > I can see why. When it's about details that are only useful for debugging, logging might be a practical alternative. No excuse for shoddy error reporting, of course.