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From: Wouter Verhelst <w@uter.be>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: Eric Blake <eblake@redhat.com>, Alex Bligh <alex@alex.org.uk>,
	qemu-devel <qemu-devel@nongnu.org>,
	nbd@other.debian.org
Subject: Re: [Qemu-devel] nbd structured reply
Date: Sat, 23 Sep 2017 15:00:36 +0200	[thread overview]
Message-ID: <20170923130036.372fgo4uhm7yfuoc@grep.be> (raw)
In-Reply-To: <9a3ce498-040d-5d8f-41d0-a2a649771528@virtuozzo.com>

On Fri, Sep 22, 2017 at 05:57:07PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> The obvious behavior of client is to fail the whole read if it received one
> error chunk.

Not necessarily.

If a user-space program requests to read X bytes of data, but there is
an error at X-N, then the obvious way to handle that is for the read()
call to return with X-N bytes first, and for the next read() call to
return with -1, and errno set to EIO.

Structured reads allow for that kind of behaviour.

-- 
Could you people please use IRC like normal people?!?

  -- Amaya Rodrigo Sastre, trying to quiet down the buzz in the DebConf 2008
     Hacklab

  parent reply	other threads:[~2017-09-23 13:01 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 [this message]
2017-10-05 11:30 ` Vladimir Sementsov-Ogievskiy
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

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