[PATCH Wily SRU] scsi_scan: don't dump trace when scsi_prep_async_scan() is called twice

[tim.gardner at canonical.com]

From: Vitaly Kuznetsov <vkuznets at redhat.com>

BugLink: http://bugs.launchpad.net/bugs/1517942

The only user of scsi_prep_async_scan() is scsi_scan_host() and it
handles the situation correctly. Move 'called twice' reporting to debug
level as well.

The issue is observed on Hyper-V: on any device add/remove event storvsc
driver calls scsi_scan_host() and in case previous scan is still running
we get the message and stack dump on console.

Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
Reviewed-by: K. Y. Srinivasan <kys at microsoft.com>
Tested-by: Alex Ng <alexng at microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit a4cf30e15ccea82a07fa5870e8af787b9ea1a672)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 drivers/scsi/scsi_scan.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f9f3f82..01ad016 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1712,8 +1712,7 @@ static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
 		return NULL;
 
 	if (shost->async_scan) {
-		shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
-		dump_stack();
+		shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
 		return NULL;
 	}
 
-- 
1.9.1