Skip to contentSkip to conversation

scsi_scan: fix queue depth initialisation problem

PATCH In review James Bottomley 3 participants 3 messages Apr 28, 2015 – May 11, 2015 SCSI

lore
Share & tools
lore

James Bottomley

author maintainer
#0 lore raw

PATCH 1/1 scsi_scan: fix queue depth initialisation problem

From: James Bottomley <[email protected]>
Date: Sun, 26 Apr 2015 11:52:46 -0700
Subject: [PATCH] scsi_scan: fix queue depth initialisation problem

Currently we blindly use the value of cmd_per_lun as the initial setting for queue_depth. This fails miserably (hangs the system) if it is zero, which is the default value for anything uninitialised in the template. The net result is that every host template has to set a value for cmd_per_lun. Instead, use a default value of 1 if the actual value is unset. This should pave the way for removing cmd_per_lun from all the templates and eventually from SCSI itself.

Signed-off-by James Bottomley <[email protected]>
drivers/scsi/scsi_scan.c +2 -1
index 60aae01..681a59a 100644
@@ -280,7 +280,8 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
 				    sdev->host->cmd_per_lun, shost->bqt,
 				    shost->hostt->tag_alloc_policy);
 	}
-	scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun);
+	scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ?
+					sdev->host->cmd_per_lun : 1);
 
 	scsi_sysfs_device_initialize(sdev);
Tested-by on v1 1/1
#1 lore raw
Quoted 12 lines · James Bottomley

From: James Bottomley <[email protected]>
Date: Sun, 26 Apr 2015 11:52:46 -0700
Subject: [PATCH] scsi_scan: fix queue depth initialisation problem

Currently we blindly use the value of cmd_per_lun as the initial setting for queue_depth. This fails miserably (hangs the system) if it is zero, which is the default value for anything uninitialised in the template. The net result is that every host template has to set a value for cmd_per_lun. Instead, use a default value of 1 if the actual value is unset. This should pave the way for removing cmd_per_lun from all the templates and eventually from SCSI itself.

Quoted 1 line
Signed-off-by James Bottomley <[email protected]>
Tested-by Hannes Reinecke <[email protected]>

Cheers,

Hannes

Signature · 9 lines
Dr. Hannes Reinecke		               zSeries & Storage
[email protected]			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html