From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36483) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fk3QC-0007ZB-Kn for qemu-devel@nongnu.org; Mon, 30 Jul 2018 04:20:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fk3QB-0007eP-Al for qemu-devel@nongnu.org; Mon, 30 Jul 2018 04:20:52 -0400 From: Markus Armbruster References: <20180725151011.25951-1-armbru@redhat.com> <5e713599-997f-7dda-917c-80902f6ef328@redhat.com> <20180728042308.GB1325070@localhost.localdomain> Date: Mon, 30 Jul 2018 10:20:36 +0200 In-Reply-To: <20180728042308.GB1325070@localhost.localdomain> (Jeff Cody's message of "Sat, 28 Jul 2018 00:23:08 -0400") Message-ID: <87600xyw17.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [RFC PATCH] rbd: Don't convert keypairs to JSON and back List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jeff Cody Cc: Eric Blake , kwolf@redhat.com, jdurgin@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, mreitz@redhat.com Jeff Cody writes: > On Wed, Jul 25, 2018 at 10:56:48AM -0500, Eric Blake wrote: >> On 07/25/2018 10:10 AM, Markus Armbruster wrote: >> >qemu_rbd_parse_filename() builds a keypairs QList, converts it to JSON, and >> >stores the resulting QString in a QDict. >> > >> >qemu_rbd_co_create_opts() and qemu_rbd_open() get the QString from the >> >QDict, pass it to qemu_rbd_set_keypairs(), which converts it back into >> >a QList. >> > >> >Drop both conversions, store the QList instead. >> > >> >This affects output of qemu-img info. Before this patch: >> > >> > $ qemu-img info rbd:rbd/testimg.raw:mon_host=192.168.15.180:rbd_cache=true:conf=/tmp/ceph.conf >> > [junk printed by Ceph library code...] >> > image: json:{"driver": "raw", "file": {"pool": "rbd", "image": "testimg.raw", "conf": "/tmp/ceph.conf", "driver": "rbd", "=keyvalue-pairs": "[\"mon_host\", \"192.168.15.180\", \"rbd_cache\", \"true\"]"}} >> > [more output, not interesting here] >> > >> >After this patch, we get >> > >> > image: json:{"driver": "raw", "file": {"pool": "rbd", "image": "testimg.raw", "conf": "/tmp/ceph.conf", "driver": "rbd", "=keyvalue-pairs": ["mon_host", "192.168.15.180", "rbd_cache", "true"]}} >> > >> >The value of member "=keyvalue-pairs" changes from a string containing >> >a JSON array to that JSON array. That's an improvement of sorts. However: >> > >> >* Should "=keyvalue-pairs" even be visible here? It's supposed to be >> > purely internal... >> >> I'd argue that since it is supposed to be internal (as evidenced by the >> leading '=' that does not name a normal variable), changing it doesn't hurt >> stability. But yes, it would be nicer if we could filter it entirely so that >> it does not appear in json: output, if it doesn't truly affect the contents >> that the guest would see. >> >> > >> >* Is this a stable interface we need to preserve, warts and all? >> >> I hope not. >> >> > >> >Signed-off-by: Markus Armbruster >> >--- >> > block/rbd.c | 50 ++++++++++++++++++++++---------------------------- >> > 1 file changed, 22 insertions(+), 28 deletions(-) >> >> I'm not yet convinced if we want this patch for 3.0 without more comments >> from the RBD experts, nor do I see too much of an issue if this doesn't go >> in until 3.1. But as to the code changes itself, I find them nice. > > Based on my IRC discussions with Markus, I believe the target for this patch > is indeed 3.1, not 3.0. Unless we conclude we want to change qemu-img info sooner rather than later, which seems unlikely.