[PATCH] scsi: scsh_dh_alua use the device timeout rather than a constant

[PATCH] scsi: scsh_dh_alua use the device timeout rather than a constant

[Brian Bunker]

Instead of using a constant for timeouts, use the timeout of the SCSI
device itself. There are reaasons why someone might want to extend
the SCSI timeout and having the constant out of sync can lead to
early timeouts.

Acked-by: Krishna Kant <krishna.kant@purestorage.com>
Signed-off-by: Brian Bunker <brian@purestorage.com>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index efb08b9b145a..7f11acf714ad 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -143,7 +143,7 @@ static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff,
 	put_unaligned_be32(bufflen, &cdb[6]);
 
 	return scsi_execute_cmd(sdev, cdb, opf, buff, bufflen,
-				ALUA_FAILOVER_TIMEOUT * HZ,
+				sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
 				ALUA_FAILOVER_RETRIES, &exec_args);
 }
 
@@ -178,7 +178,7 @@ static int submit_stpg(struct scsi_device *sdev, int group_id,
 	put_unaligned_be32(stpg_len, &cdb[6]);
 
 	return scsi_execute_cmd(sdev, cdb, opf, stpg_data,
-				stpg_len, ALUA_FAILOVER_TIMEOUT * HZ,
+				stpg_len, sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
 				ALUA_FAILOVER_RETRIES, &exec_args);
 }
 
@@ -512,7 +512,7 @@ static int alua_tur(struct scsi_device *sdev)
 	struct scsi_sense_hdr sense_hdr;
 	int retval;
 
-	retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ,
+	retval = scsi_test_unit_ready(sdev, sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
 				      ALUA_FAILOVER_RETRIES, &sense_hdr);
 	if ((sense_hdr.sense_key == NOT_READY ||
 	     sense_hdr.sense_key == UNIT_ATTENTION) &&
@@ -552,7 +552,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
 	valid_states_old = pg->valid_states;
 
 	if (!pg->expiry) {
-		unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ;
+		unsigned long transition_tmo = min(sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
+						   (unsigned long)U8_MAX * HZ);
 
 		if (pg->transition_tmo)
 			transition_tmo = pg->transition_tmo * HZ;
@@ -664,7 +665,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
 	if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0)
 		pg->transition_tmo = buff[5];
 	else
-		pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
+		pg->transition_tmo = min((sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ) / HZ,
+					 (unsigned long)U8_MAX);
 
 	if (orig_transition_tmo != pg->transition_tmo) {
 		sdev_printk(KERN_INFO, sdev,
-- 
2.52.0

Re: [PATCH] scsi: scsh_dh_alua use the device timeout rather than a constant

[Martin K. Petersen]

> Instead of using a constant for timeouts, use the timeout of the SCSI
> device itself. There are reaasons why someone might want to extend the
> SCSI timeout and having the constant out of sync can lead to early
> timeouts.

Hannes: Please opine...

-- 
Martin K. Petersen

Re: [PATCH] scsi: scsh_dh_alua use the device timeout rather than a constant

[John Garry]

On 24/02/2026 01:07, Brian Bunker wrote:
> Instead of using a constant for timeouts, use the timeout of the SCSI
> device itself. There are reaasons why someone might want to extend

reasons

> the SCSI timeout and having the constant out of sync can lead to
> early timeouts.
> 
> Acked-by: Krishna Kant <krishna.kant@purestorage.com>
> Signed-off-by: Brian Bunker <brian@purestorage.com>
> ---
>   drivers/scsi/device_handler/scsi_dh_alua.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
> index efb08b9b145a..7f11acf714ad 100644
> --- a/drivers/scsi/device_handler/scsi_dh_alua.c
> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> @@ -143,7 +143,7 @@ static int submit_rtpg(struct scsi_device *sdev, unsigned char *buff,
>   	put_unaligned_be32(bufflen, &cdb[6]);
>   
>   	return scsi_execute_cmd(sdev, cdb, opf, buff, bufflen,
> -				ALUA_FAILOVER_TIMEOUT * HZ,
> +				sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,

is sdev->request_queue->rq_timeout == 0 even ever valid? In 
queue_io_timeout_store() and sdev_store_timeout(), a timeout of 0 is 
rejected.

Also, sdev->request_queue->rq_timeout can change dynamically by 
userspace control - is that ok for these changes?

And, finally, READ_ONCE should be use for accessing 
sdev->request_queue->rq_timeout

>   				ALUA_FAILOVER_RETRIES, &exec_args);
>   }
>   
> @@ -178,7 +178,7 @@ static int submit_stpg(struct scsi_device *sdev, int group_id,
>   	put_unaligned_be32(stpg_len, &cdb[6]);
>   
>   	return scsi_execute_cmd(sdev, cdb, opf, stpg_data,
> -				stpg_len, ALUA_FAILOVER_TIMEOUT * HZ,
> +				stpg_len, sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
>   				ALUA_FAILOVER_RETRIES, &exec_args);
>   }
>   
> @@ -512,7 +512,7 @@ static int alua_tur(struct scsi_device *sdev)
>   	struct scsi_sense_hdr sense_hdr;
>   	int retval;
>   
> -	retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ,
> +	retval = scsi_test_unit_ready(sdev, sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
>   				      ALUA_FAILOVER_RETRIES, &sense_hdr);
>   	if ((sense_hdr.sense_key == NOT_READY ||
>   	     sense_hdr.sense_key == UNIT_ATTENTION) &&
> @@ -552,7 +552,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
>   	valid_states_old = pg->valid_states;
>   
>   	if (!pg->expiry) {
> -		unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ;
> +		unsigned long transition_tmo = min(sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ,
> +						   (unsigned long)U8_MAX * HZ);
>   
>   		if (pg->transition_tmo)
>   			transition_tmo = pg->transition_tmo * HZ;
> @@ -664,7 +665,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
>   	if ((buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && buff[5] != 0)
>   		pg->transition_tmo = buff[5];
>   	else
> -		pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
> +		pg->transition_tmo = min((sdev->request_queue->rq_timeout ?: ALUA_FAILOVER_TIMEOUT * HZ) / HZ,
> +					 (unsigned long)U8_MAX);
>   
>   	if (orig_transition_tmo != pg->transition_tmo) {
>   		sdev_printk(KERN_INFO, sdev,