From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38047) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCAyw-0003KA-EK for Qemu-devel@nongnu.org; Mon, 26 Mar 2012 10:33:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SCAyr-0002OM-4n for Qemu-devel@nongnu.org; Mon, 26 Mar 2012 10:33:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36719) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCAyq-0002Nv-TB for Qemu-devel@nongnu.org; Mon, 26 Mar 2012 10:33:09 -0400 Date: Mon, 26 Mar 2012 11:33:12 -0300 From: Luiz Capitulino Message-ID: <20120326113312.145235e6@doriath.home> In-Reply-To: <4F70776A.1010100@redhat.com> References: <4F702B56.8030400@redhat.com> <20120326094610.2ee5abc8@doriath.home> <4F706B80.9080402@redhat.com> <20120326102814.20e2cb87@doriath.home> <4F70776A.1010100@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Ignoring errno makes QMP errors suck List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Qemu-devel@nongnu.org, Anthony Liguori On Mon, 26 Mar 2012 16:04:26 +0200 Kevin Wolf wrote: > >> Does the patch that you mentioned add a generic way for adding an > >> (converted) errno to QMP errors? Or does it split up existing errors > >> into more and finer grained errors? > > > > The latter. The QMP errors have to be added manually. But it's just a matter > > of time to get the most used errnos added. > > Your PermissionDenied example doesn't really do this. It is a generic > error message that may occur in multiple contexts, right? So in one > context you may need a file name as additional information, in another > context permission for something completely different may be missing > (especially if you include EPERM in the same error). Yes, but it's not a severe problem. Not yet. Because most of the time the error context can be inferred from the command's context. Say, you fail to create a file where only one file could be created. But yes, we need to add a way for errors to accept optional parameters. I have a series that's almost done that moves all errors to a qapi-error.json file and auto-generates the QErrors tables. Maybe that's a first step towards more flexible errors. > I think 'OpenFileFailed' is not too bad, it's just missing a field that > gives the detail 'PermissionDenied'. I'm not sure if having > 'PermissionDenied' as the top-level error object is the best idea. I think the end result is the same, but I prefer PermissionDenied as the top level because it's slightly simpler.