Re: [Qemu-devel] [PATCH 2/3] scsi/virtio-scsi: Cleanup of I/Os that never started

[Paolo Bonzini <pbonzini@redhat.com>]

Il 14/01/2014 15:24, Eric Farman ha scritto:
> There is still a small window that occurs when a cancel I/O affects
> an asynchronous I/O operation that hasn't started.  In other words,
> when the residual data length equals the expected data length.
> 
> Today, the routine virtio_scsi_command_complete fails because the
> VirtIOSCSIReq pointer (from the hba_private field in SCSIRequest)
> was cleared earlier when virtio_scsi_complete_req was called by
> the virtio_scsi_request_cancelled routine.  As a result, the
> virtio_scsi_command_complete routine needs to simply return when
> it is processing a SCSIRequest block that was marked canceled.
> 
> Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
> ---
>  hw/scsi/virtio-scsi.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index a8fde04..49a9576 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> @@ -306,6 +306,10 @@ static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
>      VirtIOSCSIReq *req = r->hba_private;
>      uint32_t sense_len;
>  
> +    if (r->io_canceled) {
> +        return;
> +    }
> +
>      req->resp.cmd->response = VIRTIO_SCSI_S_OK;
>      req->resp.cmd->status = status;
>      if (req->resp.cmd->status == GOOD) {
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Can you please look more closely into whether patch 1 is really
necessary, include the small fix I posted into that review, and post v2
of the series?

Thanks!

Paolo