On 03/14/2014 07:00 AM, Fam Zheng wrote:
> According to SPC-4, section 4.5.2.1, 252 is the limit of sense data. So
> increase the values.
>
> Tested by hacking QEMU to fake virtio-scsi request sense len to 252.
> Without this patch the driver stops working immediately when it gets the
> request.
>
> Signed-off-by: Fam Zheng <famz@xxxxxxxxxx>
> ---
> include/linux/virtio_scsi.h | 2 +-
> include/scsi/scsi_cmnd.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/virtio_scsi.h b/include/linux/virtio_scsi.h
> index 4195b97..a437f7f 100644
> --- a/include/linux/virtio_scsi.h
> +++ b/include/linux/virtio_scsi.h
> @@ -28,7 +28,7 @@
> #define _LINUX_VIRTIO_SCSI_H
>
> #define VIRTIO_SCSI_CDB_SIZE 32
> -#define VIRTIO_SCSI_SENSE_SIZE 96
> +#define VIRTIO_SCSI_SENSE_SIZE 252
>
> /* SCSI command request, followed by data-out */
> struct virtio_scsi_cmd_req {
> diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
> index 91558a1..a64dac03 100644
> --- a/include/scsi/scsi_cmnd.h
> +++ b/include/scsi/scsi_cmnd.h
> @@ -104,7 +104,7 @@ struct scsi_cmnd {
> struct request *request; /* The command we are
> working on */
>
> -#define SCSI_SENSE_BUFFERSIZE 96
> +#define SCSI_SENSE_BUFFERSIZE 252
> unsigned char *sense_buffer;
> /* obtained by REQUEST SENSE when
> * CHECK CONDITION is received on original
>
Not without careful review.
Blindly increasing the buffersize is not a good idea; this define is
used at several locations and even within the drivers themselves.
So we cannot just increase the define for the SCSI stack.
And, btw, so far I haven't come across any issue where a sense
buffer overflow occurred. We first need to implement a proper sense
code handling (descriptor sense parsing etc) before we need to worry
about this.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
