[PATCH 2/2] Drivers: scsi: storvsc: Don't pass ATA_16 command to the host
jeff at garzik.org
Sat Mar 17 15:04:44 UTC 2012
On 03/16/2012 04:24 PM, K. Y. Srinivasan wrote:
> The current Windows hosts don't handle the ATA_16 command and furthermore
> return a generic error code after filtering the command on the host side.
> For now filter the command on the guest side until the host is modified to
> properly handle unsupported commands.
> Signed-off-by: K. Y. Srinivasan<kys at microsoft.com>
> Reviewed-by: Haiyang Zhang<haiyangz at microsoft.com>
> drivers/scsi/storvsc_drv.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index 8b967c9..783bab8 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1229,8 +1229,17 @@ static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
> * smartd sends this command and the host does not handle
> * this. So, don't send it.
> + * The current Windows hosts implement a subset of scsi commands
> + * and for the commands that are not implemented, the host filters
> + * them and returns a generic failure SRB status. I have been in
> + * discussions with the Windows team to return the appropriate SRB
> + * status code for unsupported scsi commands and while they have
> + * agreed to implement this, it is not clear when this change will be
> + * available. Consequently, filtering the command before submitting it
> + * to the host is a resonable interim solution.
> case SET_WINDOW:
> + case ATA_16:
> scmnd->result = ILLEGAL_REQUEST<< 16;
> allowed = false;
It would be even nicer to fill out a nice SCSI status for this. For an
illegal request such as this, the libata SCSI simulator
(drivers/ata/libata-scsi.c) uses a more complete sense buffer setup,
static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk,
u8 asc, u8 ascq)
cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
and calls this function for invalid/unknown/unsupported command ops thusly,
ata_scsi_set_sense(cmd, ILLEGAL_REQUEST, 0x20, 0x0);
/* "Invalid command operation code" */
Supplying asc/ascq provides additional information that may be useful in
determining whether or not to retry, provide better error diagnostics, etc.
The asc/ascq values are found in the SCSI standards documents.
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