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: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 9 insertions, 3 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index d01e423ef44b..403a63310fb1 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/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;
         }
 
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index e113c757d555..3a22da73d59a 100644
--- a/include/scsi/scsi_host.h
+++ b/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
          */