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Date: Fri, 22 Aug 2014 12:57:15 +0800
From: Fam Zheng <famz@redhat.com>
Message-ID: <20140822045715.GF3410@T430.redhat.com>
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Subject: Re: [Qemu-devel] [RFC PATCH 9/9] scsi: Cancel request asynchronously
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>

On Thu, 08/21 14:19, Paolo Bonzini wrote:
> Il 21/08/2014 13:56, Fam Zheng ha scritto:
> > We are blocking the whole VM, which means that an irresponsive storage
> > backend will hang the whole guest. Let's switch to bdrv_aio_cancel_async
> > to improve this.
> 
> Unforuntately, the TMF must only return after the request has been
> canceled.  I think you need to add a scsi_cancel_io_async function, and
> keep all the remaining machinery (also, you need a better commit message
> that explains what you are removing and the new invariants).
> 
> Then in virtio-scsi you need to add a list of "dependent" (controlq)
> VirtIOSCSIReq to the "main" (requestq) VirtIOSCSIReq, and complete them
> all after signaling the completion of the main request.

OK, I didn't know that. I'll try again :)

Thanks,
Fam