qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: Eric Blake <eblake@redhat.com>, Wouter Verhelst <w@uter.be>,
	Alex Bligh <alex@alex.org.uk>
Cc: qemu-devel <qemu-devel@nongnu.org>,
	"nbd-general@lists.sourceforge.net"
	<nbd-general@lists.sourceforge.net>
Subject: Re: [Qemu-devel] nbd structured reply
Date: Thu, 5 Oct 2017 14:30:07 +0300	[thread overview]
Message-ID: <c3c3bfdb-3e8f-5443-3d6c-52ab5a95bc63@virtuozzo.com> (raw)
In-Reply-To: <cecb7a50-6913-0d88-59b4-805463aba790@virtuozzo.com>

21.09.2017 15:18, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
>
> I'm about this:
>
> "A server SHOULD try to minimize the number of chunks sent in a reply, 
> but MUST NOT mark a chunk as final if there is still a possibility of 
> detecting an error before transmission of that chunk completes"
>
> What do we mean by "possibility"? Formally, such possibility exists 
> always, so, we'll never mark a chunk as final.
>

One more question:

for |NBD_REPLY_TYPE_ERROR and ||NBD_REPLY_TYPE_ERROR_OFFSET, why do we 
need message_length field? why not to calc it as chunk.lenght - 4 for 
||NBD_REPLY_TYPE_ERROR and chunk.lenght - 12 for 
||NBD_REPLY_TYPE_ERROR_OFFSET?

For example, with NBD_REPLY_TYPE_OFFSET_DATA variable data length is 
calculated, not specified separately.

What is the reason for server to send NBD_REPLY_TYPE_ERROR with 
message_lenght < chunk.lenght - 4?
|

-- 
Best regards,
Vladimir

  parent reply	other threads:[~2017-10-05 11:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-21 12:18 [Qemu-devel] nbd structured reply Vladimir Sementsov-Ogievskiy
2017-09-21 13:55 ` Eric Blake
2017-09-22 14:57   ` Vladimir Sementsov-Ogievskiy
2017-09-22 20:36     ` Eric Blake
2017-09-23 11:00       ` Vladimir Sementsov-Ogievskiy
2017-09-23 13:00     ` Wouter Verhelst
2017-10-05 11:30 ` Vladimir Sementsov-Ogievskiy [this message]
2017-10-05 12:27   ` Vladimir Sementsov-Ogievskiy
2017-10-05 13:37   ` Eric Blake
2017-10-06  6:39     ` Vladimir Sementsov-Ogievskiy
  -- strict thread matches above, loose matches on Subject: below --
2017-09-21 12:08 Vladimir Sementsov-Ogievskiy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c3c3bfdb-3e8f-5443-3d6c-52ab5a95bc63@virtuozzo.com \
    --to=vsementsov@virtuozzo.com \
    --cc=alex@alex.org.uk \
    --cc=eblake@redhat.com \
    --cc=nbd-general@lists.sourceforge.net \
    --cc=qemu-devel@nongnu.org \
    --cc=w@uter.be \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).