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Date: Mon, 22 Sep 2008 14:21:05 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] [PATCH] scsi-generic: decode correctly SCSI tape
	commands
References: <1222099458.4151.20.camel@frecb07144>
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To: qemu-devel@nongnu.org

Laurent Vivier wrote:
> This patch allows to use a "real" SCSI tape with qemu using
> "-drive /dev/sgX,if=scsi".
>
> It allows to decode correctly transfer length when the type of the
> device is a tape.
>
> Some issues subsist when the application reading the tape tries to go
> beyond the end of the stream (but they must be corrected at the SCSI
> controller level).
>   

You have some tab/whitespace damage in this patch

> @@ -75,6 +77,7 @@ struct SCSIDeviceState
>  {
>      SCSIRequest *requests;
>      BlockDriverState *bdrv;
> +    int type;
>      int blocksize;
>      int lun;
>      scsi_completionfn completion;
> @@ -163,7 +166,7 @@ static void scsi_command_complete(void *
>          } else if ((s->driver_status & SG_ERR_DRIVER_SENSE) == 0)
>              sense = NO_SENSE;
>          else
> -            sense = s->sensebuf[2] & 0x0f;
> +            sense = s->sensebuf[2];
>      }
>  
>      DPRINTF("Command complete 0x%p tag=0x%x sense=%d\n", r, r->tag, sense);
> @@ -273,10 +276,15 @@ static void scsi_read_data(SCSIDevice *d
>  
>      if (r->cmd[0] == REQUEST_SENSE && s->driver_status & SG_ERR_DRIVER_SENSE)
>      {
> -        memcpy(r->buf, s->sensebuf, 16);
> +	int len;
>   

Right here.

> +        len = r->len > SCSI_SENSE_BUF_SIZE ? SCSI_SENSE_BUF_SIZE : r->len;
>   

Just use len = MIN(r->len, SCSI_SENSE_BUF_SIZE);

The rest looks pretty straight forward.

Regards,

Anthony Liguori