From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: Alex Bligh <alex@alex.org.uk>, Wouter Verheist <w@uter.be>,
nbd-general@lists.sourceforge.net
Cc: Kevin Wolf <kwolf@redhat.com>,
stefanha@redhat.com, John Snow <jsnow@redhat.com>,
qemu-devel@nongnu.org, Pavel Borzenkov <pborzenkov@virtuozzo.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Markus Pargmann <mpa@pengutronix.de>,
"Denis V . Lunev" <den@openvz.org>
Subject: Re: [Qemu-devel] [PATCH] Further tidy-up on block status
Date: Tue, 27 Dec 2016 17:09:21 +0300 [thread overview]
Message-ID: <71d6f278-be19-eaeb-7277-c3e6e4512e67@virtuozzo.com> (raw)
In-Reply-To: <20161214150840.10899-1-alex@alex.org.uk>
A bit out of topic, but...
> structured replies via `NBD_OPT_STRUCTURED_REPLY`. Conversely, if
> structured replies are negotiated, the server MUST use a
> structured reply for any response with a payload, and MUST NOT use
> a simple reply for `NBD_CMD_READ` (even for the case of an early
> `EINVAL` due to bad flags), but MAY use either a simple reply or a
> structured reply to all other requests.
What was the reason for it? Why not to negotiate forced structured read
separately? Actually, this spec forces any server, which wants to
implement structured reply implement structured read too. But what if it
don't want to? If it only wants to implement BLOCK_STATUS?
So, what about changing it, to allow BLOCK_STATUS (or other future
structured replies) without structured read? Structured read is good
only for sparse formats, when BLOCK_STATUS is more global. I understand,
that servers may implement simple (and useless) one-chunk structured
read, but I think that it is better to fix the spec, to not provoke
servers use such workaround.
--
Best regards,
Vladimir
next prev parent reply other threads:[~2016-12-27 14:09 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-14 15:08 [Qemu-devel] [PATCH] Further tidy-up on block status Alex Bligh
2016-12-14 16:25 ` Vladimir Sementsov-Ogievskiy
2016-12-14 16:38 ` Alex Bligh
2016-12-14 17:05 ` Vladimir Sementsov-Ogievskiy
2016-12-14 17:36 ` Alex Bligh
2016-12-14 17:55 ` Vladimir Sementsov-Ogievskiy
2016-12-14 18:13 ` [Qemu-devel] [Nbd] " Wouter Verhelst
2016-12-14 18:18 ` Alex Bligh
2016-12-14 18:49 ` Wouter Verhelst
2016-12-14 19:01 ` Alex Bligh
2016-12-14 20:10 ` Wouter Verhelst
2016-12-26 15:57 ` Vladimir Sementsov-Ogievskiy
2016-12-29 16:08 ` Alex Bligh
2016-12-29 16:35 ` Vladimir Sementsov-Ogievskiy
2016-12-14 18:51 ` Alex Bligh
2016-12-14 20:18 ` Wouter Verhelst
2016-12-15 10:04 ` Alex Bligh
2016-12-15 15:03 ` Wouter Verhelst
2016-12-15 16:32 ` Alex Bligh
2016-12-15 16:49 ` Wouter Verhelst
2016-12-15 17:34 ` Alex Bligh
2016-12-16 15:52 ` Wouter Verhelst
2016-12-16 16:25 ` Alex Bligh
2016-12-17 8:34 ` Wouter Verhelst
2016-12-17 9:41 ` Alex Bligh
2016-12-14 18:17 ` [Qemu-devel] " Alex Bligh
2016-12-26 14:52 ` Vladimir Sementsov-Ogievskiy
2016-12-28 0:18 ` [Qemu-devel] [Nbd] " Wouter Verhelst
2016-12-29 16:04 ` Alex Bligh
2016-12-29 16:28 ` Vladimir Sementsov-Ogievskiy
2016-12-14 16:58 ` [Qemu-devel] " Eric Blake
2016-12-14 17:03 ` Alex Bligh
2016-12-14 17:09 ` [Qemu-devel] [Nbd] " Wouter Verhelst
2016-12-14 17:33 ` Vladimir Sementsov-Ogievskiy
2016-12-14 17:39 ` Alex Bligh
2016-12-14 20:47 ` John Snow
2018-05-03 16:18 ` Eric Blake
2018-05-03 17:26 ` Eric Blake
2018-05-04 6:40 ` Wouter Verhelst
2016-12-27 14:09 ` Vladimir Sementsov-Ogievskiy [this message]
2016-12-27 15:56 ` [Qemu-devel] " Eric Blake
2016-12-29 16:14 ` Alex Bligh
2017-01-11 15:31 ` Vladimir Sementsov-Ogievskiy
2017-01-11 19:00 ` Alex Bligh
2017-01-12 7:05 ` Vladimir Sementsov-Ogievskiy
2017-01-12 13:11 ` Alex Bligh
2017-01-13 9:48 ` Vladimir Sementsov-Ogievskiy
2017-01-13 10:29 ` Alex Bligh
2017-01-16 12:26 ` Vladimir Sementsov-Ogievskiy
2017-01-12 11:43 ` Vladimir Sementsov-Ogievskiy
2017-01-12 13:16 ` Alex Bligh
2017-01-20 17:04 ` Vladimir Sementsov-Ogievskiy
2017-01-20 18:00 ` Alex Bligh
2017-01-20 19:35 ` Eric Blake
2017-01-21 12:25 ` [Qemu-devel] [Nbd] " Wouter Verhelst
2018-02-16 12:35 ` Eric Blake
2018-02-16 13:53 ` Vladimir Sementsov-Ogievskiy
2018-02-16 16:10 ` Eric Blake
2018-02-28 13:08 ` Wouter Verhelst
2018-02-28 20:26 ` Eric Blake
2018-02-28 20:29 ` Eric Blake
2018-03-01 9:54 ` Vladimir Sementsov-Ogievskiy
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