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Date: Fri, 11 Jul 2014 12:26:58 +0200
From: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20140711102658.GA3976@noname.redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] block/quorum: make quorum_getlength error
 message user friendly
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To: Liu Yuan <namei.unix@gmail.com>
Cc: qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>, Benoit Canet <benoit@irqsave.net>

Am 11.07.2014 um 09:34 hat Liu Yuan geschrieben:
> When start quorum driver with 2 different sized images, we get:
> 
> qemu-system-x86_64: -drive if=virtio,driver=quorum...: Could not refresh total \
> sector count: Input/output error
> 
> EIO would confuse users. With this patch, the error message goes like
> 
> Children images are not in the same size
> qemu-system-x86_64: -drive if=virtio,driver=quorum...: Could not refresh total \
> sector count: Invalid argument
> 
> Cc: Benoit Canet <benoit@irqsave.net>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Liu Yuan <namei.unix@gmail.com>

I think it would be better to do this check in quorum_open() instead of
relying on bdrv_open() to perform a bdrv_getlength(). As a bonus,
quorum_open() has an Error argument, so we wouldn't have to use
something like error_printf(), which doesn't work well for QMP commands.

Kevin