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Date: Thu, 05 Jun 2014 06:09:32 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2 8/8] virtio-blk: Fill in
 VirtIOBlockReq.out in dataplane code
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To: Fam Zheng <famz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>

Il 05/06/2014 05:50, Fam Zheng ha scritto:
>> > Can you try moving the req allocation and assignments inside process_request
>> > instead?  Then you can fill in req->out directly without the struct
>> > assignment.
>> >
> The owners of req are do_rdwr_cmd and do_flush_cmd, but do_scsi_cmd and
> do_get_id_cmd don't need to allocate.

They don't need it, but using req there and freeing it in 
complete_request_early perhaps could simplify the code.

After all, the first three arguments of complete_request_early (s, elem, 
inhdr) are a duplicate of VirtIOBlockReq and do_flush_cmd is already 
doing a free after complete_request_early.

Paolo

> Moving the allocation means transfering the ownership from process_request to
> respective cmd functions, and it's not used in two out of four. Not sure much
> better than this way, but that's doable.