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From: Nicholas Thomas <nick@bytemark.co.uk>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 3/3] block/nbd: Make the NBD block device use the AIO interface
Date: Thu, 17 Feb 2011 19:28:37 +0000	[thread overview]
Message-ID: <1297970917.12551.56.camel@den> (raw)
In-Reply-To: <1297960482.21300.62.camel@desk4.office.bytemark.co.uk>

Ho hum.

On Thu, 2011-02-17 at 16:34 +0000, Nicholas Thomas wrote:
> Signed-off-by: Nick Thomas <nick@bytemark.co.uk>
> ---
>  block/nbd.c |  549
> ++++++++++++++++++++++++++++++++++++++++++++++++++---------
>  1 files changed, 464 insertions(+), 85 deletions(-)

Additional testing has revealed that this code breaks the stock
nbd-server (the one on sourceforge) when large (well, 1.3MiB) write
requests are sent to it.

The server process receives a valid-looking NBD write request header
followed by the first ~200K of the write data (sent from
add_aio_request). It then exits (errcode 1).

add_aio_request returns the error, and subsequently, read_aio_response
picks up the aioreq and loops forever, trying to read a response from a
closed socket.

Reads and small writes seem to work fine, however.

I'll debug the server tomorrow and try to see what's breaking it - no
good having a technically compliant client if it breaks the most common
server out there ;)

/Nick

  reply	other threads:[~2011-02-17 19:28 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-14 19:40 [Qemu-devel] NBD block device backend - 'improvements' Nicholas Thomas
2011-02-14 20:32 ` Stefan Hajnoczi
2011-02-15 11:09   ` Kevin Wolf
2011-02-15 21:26     ` Nicholas Thomas
2011-02-16 12:00       ` Kevin Wolf
2011-02-17 16:27         ` [Qemu-devel] " Nicholas Thomas
2011-02-17 16:34         ` [Qemu-devel] [PATCH 1/3] NBD library: whitespace changes Nicholas Thomas
2011-02-17 16:34         ` [Qemu-devel] [PATCH 2/3] NBD library: add aio-compatible read/write function Nicholas Thomas
2011-02-17 16:34         ` [Qemu-devel] [PATCH 3/3] block/nbd: Make the NBD block device use the AIO interface Nicholas Thomas
2011-02-17 19:28           ` Nicholas Thomas [this message]
2011-02-18 12:16             ` [Qemu-devel] [PATCH 3/3 v2] " Nicholas Thomas
2011-02-18 12:23               ` Kevin Wolf
2011-02-18 12:55                 ` Nicholas Thomas

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