scsi: report 'INQUIRY result too short' once per host

Some host adapters (e.g. Hyper-V storvsc) are known for not respecting
the SPC-2/3/4 requirement for 'INQUIRY data (see table ...) shall
contain at least 36 bytes'. As a result we get tons on 'scsi 0:7:1:1:
scsi scan: INQUIRY result too short (5), using 36' messages on
console. This can be problematic for slow consoles. Introduce
short_inquiry flag in struct Scsi_Host to print the message once per
host.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_scan.c

@@ -702,9 +702,12 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	 * strings.
 	 */
 	if (sdev->inquiry_len < 36) {
-		sdev_printk(KERN_INFO, sdev,
-			    "scsi scan: INQUIRY result too short (%d),"
-			    " using 36\n", sdev->inquiry_len);
+		if (!sdev->host->short_inquiry) {
+			shost_printk(KERN_INFO, sdev->host,
+				    "scsi scan: INQUIRY result too short (%d),"
+				    " using 36\n", sdev->inquiry_len);
+			sdev->host->short_inquiry = 1;
+		}
 		sdev->inquiry_len = 36;
 	}
 

include/scsi/scsi_host.h

@@ -673,6 +673,9 @@ struct Scsi_Host {
 	unsigned use_blk_mq:1;
 	unsigned use_cmd_list:1;
 
+	/* Host responded with short (<36 bytes) INQUIRY result */
+	unsigned short_inquiry:1;
+
 	/*
 	 * Optional work queue to be utilized by the transport
 	 */