From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55448) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fjGlB-0005SJ-BX for qemu-devel@nongnu.org; Sat, 28 Jul 2018 00:23:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fjGlA-0005sx-9L for qemu-devel@nongnu.org; Sat, 28 Jul 2018 00:23:17 -0400 Date: Sat, 28 Jul 2018 00:23:08 -0400 From: Jeff Cody Message-ID: <20180728042308.GB1325070@localhost.localdomain> References: <20180725151011.25951-1-armbru@redhat.com> <5e713599-997f-7dda-917c-80902f6ef328@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5e713599-997f-7dda-917c-80902f6ef328@redhat.com> 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: Eric Blake Cc: Markus Armbruster , qemu-devel@nongnu.org, kwolf@redhat.com, jdurgin@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com 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. > > Reviewed-by: Eric Blake > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org >