Re: [Qemu-devel] [Nbd] [PATCH] Further tidy-up on block status

From: Alex Bligh <alex@alex.org.uk>
To: Wouter Verhelst <w@uter.be>
Cc: Alex Bligh <alex@alex.org.uk>,
	Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	"nbd-general@lists.sourceforge.net"
	<nbd-general@lists.sourceforge.net>,
	Kevin Wolf <kwolf@redhat.com>, "Denis V . Lunev" <den@openvz.org>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"Stefan stefanha@redhat. com" <stefanha@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>
Subject: Re: [Qemu-devel] [Nbd] [PATCH] Further tidy-up on block status
Date: Thu, 29 Dec 2016 16:04:38 +0000	[thread overview]
Message-ID: <E57C32F9-8732-4F5F-AA67-997BB729F339@alex.org.uk> (raw)
In-Reply-To: <20161228001855.ukrtvzeictke4ex2@grep.be>

> On 28 Dec 2016, at 00:18, Wouter Verhelst <w@uter.be> wrote:
> 
> On Mon, Dec 26, 2016 at 05:52:54PM +0300, Vladimir Sementsov-Ogievskiy wrote:
>> Shouldn't we add some flags to REP_META_CONTEXT, for client to be insure, is
>> returned string a direct context name or some kind of wildcard? Just a flags
>> field, with one flag defined for now: NBD_REP_META_CONTEXT_LEAF and others
>> reserved.
> 
> I think it should be up to the metadata context namespace definition to
> define which syntax represents a direct context name and which
> represents a wildcard (if the latter are supported).
> 
> A client which doesn't know what a given metadata context implements
> can't reasonably ask for information from that context anyway (since
> then the client wouldn't know what to do with the returned information),
> so it doesn't help much to add a flag here.

I agree.

Vladimir: if this isn't clear from the text, please suggest a change.

-- 
Alex Bligh