diff mbox series

[1/3] scsi: storvsc: Miscellaneous code cleanups

Message ID 1622827263-12516-1-git-send-email-mikelley@microsoft.com (mailing list archive)
State Accepted
Headers show
Series [1/3] scsi: storvsc: Miscellaneous code cleanups | expand

Commit Message

Michael Kelley (LINUX) June 4, 2021, 5:21 p.m. UTC
As general cleanup and in preparation for subsequent patches:
* Use min() instead of open coding
* Use set_host_byte() and status_byte() instead of open coding
  access to scsi_status field
* Collapse nested "if" statements to reduce indentation
* Fix other indentation
* Remove extra blank lines

No functional changes.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 drivers/scsi/storvsc_drv.c | 40 ++++++++++++++++------------------------
 1 file changed, 16 insertions(+), 24 deletions(-)

Comments

Martin K. Petersen June 16, 2021, 2:25 a.m. UTC | #1
Michael,

> As general cleanup and in preparation for subsequent patches:

Applied 1-3 to 5.14/scsi-staging.

Since Hannes' series has deprecated status_byte() and CHECK_CONDITION I
had to tweak that portion. Please verify my conflict resolution.

Thanks!
Michael Kelley (LINUX) June 16, 2021, 7:54 p.m. UTC | #2
From: Martin K. Petersen <martin.petersen@oracle.com> Sent: Tuesday, June 15, 2021 7:25 PM
> 
> Michael,
> 
> > As general cleanup and in preparation for subsequent patches:
> 
> Applied 1-3 to 5.14/scsi-staging.
> 
> Since Hannes' series has deprecated status_byte() and CHECK_CONDITION I
> had to tweak that portion. Please verify my conflict resolution.
> 

Unfortunately, it's not quite right.  The line of code in question needs to be

if ((vstor_packet->vm_srb.scsi_status & 0xFF) == SAM_STAT_CHECK_CONDITION &&

The status_byte() helper was doing the masking as well as the right shift, so the
masking will need to be open coded.  The replacement get_status_byte() helper 
won't work here because it's based on a scsi_cmnd structure.

Michael
Martin K. Petersen June 16, 2021, 8:06 p.m. UTC | #3
Hello Michael,

> Unfortunately, it's not quite right.  The line of code in question
> needs to be
>
> if ((vstor_packet->vm_srb.scsi_status & 0xFF) == SAM_STAT_CHECK_CONDITION &&

> The status_byte() helper was doing the masking as well as the right
> shift, so the masking will need to be open coded.

CHECK_CONDITION is obsolete so no shifting is required for the SAM
status. And as far as I can tell vm_srb.scsi_status is a u8:

struct vmscsi_request {
        u16 length;
        u8 srb_status;
        u8 scsi_status;
[...]
Michael Kelley (LINUX) June 16, 2021, 8:10 p.m. UTC | #4
From: Martin K. Petersen <martin.petersen@oracle.com> Sent: Wednesday, June 16, 2021 1:07 PM
> 
> > Unfortunately, it's not quite right.  The line of code in question
> > needs to be
> >
> > if ((vstor_packet->vm_srb.scsi_status & 0xFF) == SAM_STAT_CHECK_CONDITION &&
> 
> > The status_byte() helper was doing the masking as well as the right
> > shift, so the masking will need to be open coded.
> 
> CHECK_CONDITION is obsolete so no shifting is required for the SAM
> status. And as far as I can tell vm_srb.scsi_status is a u8:
> 
> struct vmscsi_request {
>         u16 length;
>         u8 srb_status;
>         u8 scsi_status;
> [...]
> 

Indeed, you are right!  I was trying to preserve the masking with 0xFF
from the original code before my patch, but that masking was
spurious.  :-(   So yes, it's good.

Thanks,

Michael
diff mbox series

Patch

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index e6718a7..9996e8b 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1160,17 +1160,16 @@  static void storvsc_on_io_completion(struct storvsc_device *stor_device,
 		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
 	}
 
-
 	/* Copy over the status...etc */
 	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 
-	/* Validate sense_info_length (from Hyper-V) */
-	if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
-		vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
-
-	stor_pkt->vm_srb.sense_info_length =
-	vstor_packet->vm_srb.sense_info_length;
+	/*
+	 * Copy over the sense_info_length, but limit to the known max
+	 * size if Hyper-V returns a bad value.
+	 */
+	stor_pkt->vm_srb.sense_info_length = min_t(u8, sense_buffer_size,
+		vstor_packet->vm_srb.sense_info_length);
 
 	if (vstor_packet->vm_srb.scsi_status != 0 ||
 	    vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
@@ -1180,33 +1179,26 @@  static void storvsc_on_io_completion(struct storvsc_device *stor_device,
 			vstor_packet->vm_srb.scsi_status,
 			vstor_packet->vm_srb.srb_status);
 
-	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
-		/* CHECK_CONDITION */
-		if (vstor_packet->vm_srb.srb_status &
-			SRB_STATUS_AUTOSENSE_VALID) {
-			/* autosense data available */
-
-			storvsc_log(device, STORVSC_LOGGING_WARN,
-				"stor pkt %p autosense data valid - len %d\n",
-				request, vstor_packet->vm_srb.sense_info_length);
+	if (status_byte(vstor_packet->vm_srb.scsi_status) == CHECK_CONDITION
+	   && (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID)) {
 
-			memcpy(request->cmd->sense_buffer,
-			       vstor_packet->vm_srb.sense_data,
-			       vstor_packet->vm_srb.sense_info_length);
+		storvsc_log(device, STORVSC_LOGGING_WARN,
+			"stor pkt %p autosense data valid - len %d\n",
+			request, vstor_packet->vm_srb.sense_info_length);
 
-		}
+		memcpy(request->cmd->sense_buffer,
+		       vstor_packet->vm_srb.sense_data,
+		       stor_pkt->vm_srb.sense_info_length);
 	}
 
 	stor_pkt->vm_srb.data_transfer_length =
-	vstor_packet->vm_srb.data_transfer_length;
+			vstor_packet->vm_srb.data_transfer_length;
 
 	storvsc_command_completion(request, stor_device);
 
 	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 		stor_device->drain_notify)
 		wake_up(&stor_device->waiting_to_drain);
-
-
 }
 
 static void storvsc_on_receive(struct storvsc_device *stor_device,
@@ -1675,7 +1667,7 @@  static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
 	 * this. So, don't send it.
 	 */
 	case SET_WINDOW:
-		scmnd->result = DID_ERROR << 16;
+		set_host_byte(scmnd, DID_ERROR);
 		allowed = false;
 		break;
 	default: