scsi: sd: Only print updates to permanent stream count

JIRA: https://issues.redhat.com/browse/RHEL-79409

commit 961990e
Author: John Garry <john.g.garry@oracle.com>
Date:   Fri Apr 12 09:44:07 2024 +0000

    scsi: sd: Only print updates to permanent stream count

    Just rescanning a partition causes a print similar to the following to
    appear:

    [    1.484964] sd 0:0:0:0: [sda] permanent stream count = 5

    This is bothersome, so only print this message for an update.

    Fixes: 4f53138 ("scsi: sd: Translate data lifetime information")
    Signed-off-by: John Garry <john.g.garry@oracle.com>
    Link: https://lore.kernel.org/r/20240412094407.496251-1-john.g.garry@oracle.com
    Reviewed-by: Bart Van Assche <bvanassche@acm.org>
    Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Author: Ming Lei

drivers/scsi/sd.c

@@ -3243,6 +3243,7 @@ static void sd_read_io_hints(struct scsi_disk *sdkp, unsigned char *buffer)
 {
 	struct scsi_device *sdp = sdkp->device;
 	const struct scsi_io_group_descriptor *desc, *start, *end;
+	u16 permanent_stream_count_old;
 	struct scsi_sense_hdr sshdr;
 	struct scsi_mode_data data;
 	int res;
@@ -3263,12 +3264,13 @@ static void sd_read_io_hints(struct scsi_disk *sdkp, unsigned char *buffer)
 	for (desc = start; desc < end; desc++)
 		if (!desc->st_enble || !sd_is_perm_stream(sdkp, desc - start))
 			break;
+	permanent_stream_count_old = sdkp->permanent_stream_count;
 	sdkp->permanent_stream_count = desc - start;
 	if (sdkp->rscs && sdkp->permanent_stream_count < 2)
 		sd_printk(KERN_INFO, sdkp,
 			  "Unexpected: RSCS has been set and the permanent stream count is %u\n",
 			  sdkp->permanent_stream_count);
-	else if (sdkp->permanent_stream_count)
+	else if (sdkp->permanent_stream_count != permanent_stream_count_old)
 		sd_printk(KERN_INFO, sdkp, "permanent stream count = %d\n",
 			  sdkp->permanent_stream_count);
 }