[PATCHv2] scsi: Fix failed request error code

[Hannes Reinecke <hare@suse.de>]

With the introduction of commit e39a97353e53 ("scsi: core: return
BLK_STS_OK for DID_OK in __scsi_error_from_host_byte()"), a command that
failed with hostbyte=DID_OK and driverbyte=DRIVER_SENSE but lacking
additional sense information will have a return code set to BLK_STS_OK.
This results in the request issuer to see successful request execution
despite the failure. An example of such case is an unaligned write on a
host managed ZAC disk connected to a SAS HBA with a malfunctioning SAT.
The unaligned write command gets aborted but has no additional sense
information.

sd 10:0:0:0: [sde] tag#3905 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
sd 10:0:0:0: [sde] tag#3905 Sense Key : Aborted Command [current]
sd 10:0:0:0: [sde] tag#3905 Add. Sense: No additional sense information
sd 10:0:0:0: [sde] tag#3905 CDB: Write(16) 8a 00 00 00 00 00 02 0c 00 01 00 00 00 01 00 00
print_req_error: I/O error, dev sde, sector 274726920

In scsi_io_completion(), sense key handling to not change the request
error code and success being reported to the issuer.

Fix this by making sure that the error code always indicates an error
if scsi_io_completion() decide that the action to be taken for a failed
command is to not retry it and terminate it immediately (ACTION_FAIL) .

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Fixes: e39a97353e53 ("scsi: core: return BLK_STS_OK for DID_OK in __scsi_error_from_host_byte()")
Cc: <stable@vger.kernel.org>
---
 drivers/scsi/scsi_lib.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 393f9db8f41b..9389c41e2829 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -905,6 +905,12 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		goto requeue;
 
 	error = __scsi_error_from_host_byte(cmd, result);
+	/*
+	 * If the hostbyte was DID_OK, but the sense code is valid
+	 * we always should set BLK_STS_IOERR.
+	 */
+	if (error == BLK_STS_OK && sense_valid)
+		error = BLK_STS_IOERR;
 
 	if (host_byte(result) == DID_RESET) {
 		/* Third party bus reset or reset for error recovery
-- 
2.12.3