[dm-devel] [PATCH v2] [SCSI] scsi_error: classify some ILLEGAL_REQUEST sense as a permanent TARGET_ERROR

[Mike Snitzer <snitzer redhat com>]

Permanent target failures are non-retryable and should be classified as
TARGET_ERROR; otherwise dm-multipath will retry an IO request that will
always fail at the target.

A SCSI command that fails with ILLEGAL_REQUEST sense and Additional
sense 0x20, 0x21, 0x24 or 0x26 represents a permanent TARGET_ERROR.

Signed-off-by: Mike Snitzer <snitzer redhat com>
---
 drivers/scsi/scsi_error.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

v2: revised patch header to not be hyper-focused on WRITE SAME failures

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index dc6131e..33d3a50 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -366,6 +366,14 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
 			return TARGET_ERROR;
 
 	case ILLEGAL_REQUEST:
+		if (sshdr.asc == 0x20 || /* Invalid command operation code */
+		    sshdr.asc == 0x21 || /* Logical block address out of range */
+		    sshdr.asc == 0x24 || /* Invalid field in cdb */
+		    sshdr.asc == 0x26) { /* Parameter value invalid */
+			return TARGET_ERROR;
+		}
+		return SUCCESS;
+
 	default:
 		return SUCCESS;
 	}