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Date: Fri, 16 Nov 2012 18:38:48 +0100
From: Peter Lieven <pl@dlhnet.de>
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Subject: Re: [Qemu-devel] [PATCH] iscsi: fix deadlock during login
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To: Kevin Wolf <kwolf@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, ronnie sahlberg <ronniesahlberg@gmail.com>

Am 16.11.2012 11:38, schrieb Kevin Wolf:
> Am 15.11.2012 17:37, schrieb Paolo Bonzini:
>> Il 15/11/2012 17:13, ronnie sahlberg ha scritto:
>>> On Thu, Nov 15, 2012 at 7:54 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>>> Il 15/11/2012 15:57, ronnie sahlberg ha scritto:
>>>>> I dont know if we should switch to use synchronous code here.
>>>>> It is much nicer if all code is async.
>>>> bdrv_open is generally synchronous, so I think Peter's patch is ok.
>>> I was thinking about the case where you disconnect/reconnect a device
>>> at runtime. Like swapping the medium in a CDROM.
>>> If bdrv_open() is synchronous and blocks for a long time, would that
>>> not impact the rest of QEMU?
>> Yes, it's not optimal, but VCPUs would still run until they request I/O.
>>   But usually iscsi devices should be non-removable, no?  That leaves
>> hotplug as the only problematic case.
> I guess we need a bdrv_co_open() for the long term.
but for now its save to implement iscsi_open (and iscsi_create) completely
sync?

Peter
>
> Kevin