diff mbox

[PATCHv2] scsi: Fix failed request error code

Message ID 20180404072734.21718-1-hare@suse.de (mailing list archive)
State Superseded
Headers show

Commit Message

Hannes Reinecke April 4, 2018, 7:27 a.m. UTC
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(+)

Comments

Bart Van Assche April 4, 2018, 3:44 p.m. UTC | #1
On Wed, 2018-04-04 at 09:27 +0200, Hannes Reinecke wrote:
> 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


__scsi_error_from_host_byte() has two callers. Why does this patch only
update one of these two callers?

Regarding commit e39a97353e53, the description of that commit is as follows:
"When converting __scsi_error_from_host_byte() to BLK_STS error codes the
case DID_OK was forgotten, resulting in it always returning an error."
However, the comment above that function reads as follows: "translate SCSI
error code into errno". If I have a look at the v4.12 SCSI core (before the
blkstatus_t conversion) then I see that __scsi_error_from_host_byte() never
returns 0. That means that the description of commit e39a97353e53 ("scsi:
core: return BLK_STS_OK for DID_OK in __scsi_error_from_host_byte()") is
wrong. Does that mean that commit e39a97353e53 should be reverted?

Thanks,

Bart.
Douglas Gilbert April 4, 2018, 3:44 p.m. UTC | #2
On 2018-04-04 03:27 AM, Hannes Reinecke wrote:
> 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)

&& !sense_deferred

Doug Gilbert

> +		error = BLK_STS_IOERR;
>   
>   	if (host_byte(result) == DID_RESET) {
>   		/* Third party bus reset or reset for error recovery
>
diff mbox

Patch

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