[PATCH RESEND 2/2] Drivers: scsi: storvsc: Don't pass ATA_16 command to the host

K. Y. Srinivasan
2012-03-19T00:12:43Z

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.

I would like to thank Jeff Garzik <jgpobox@gmail.com> and
Douglas Gilbert <dgilbert@interlog.com> for suggesting the correct approach
here.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/scsi/storvsc_drv.c | 14 +++++++++++++-
1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 018c363..66e9bdd 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1233,9 +1233,21 @@ 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:
- scmnd->result = ILLEGAL_REQUEST << 16;
+ case ATA_16:
+ scmnd->result = ((DRIVER_SENSE << 24) |
+ SAM_STAT_CHECK_CONDITION);
+ scsi_build_sense_buffer(0, scmnd->sense_buffer,
+ ILLEGAL_REQUEST, 0x20, 0);
allowed = false;
break;
default:
--
1.7.4.1