sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes

During revalidate we check whether device capacity has changed before we
decide whether to output disk information or not.

The check for old capacity failed to take into account that we scaled
sdkp->capacity based on the reported logical block size. And therefore
the capacity test would always fail for devices with sectors bigger than
512 bytes and we would print several copies of the same discovery
information.

Avoid scaling sdkp->capacity and instead adjust the value on the fly
when setting the block device capacity and generating fake C/H/S
geometry.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <stable@vger.kernel.org>
Reported-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 5f2a84a..654630b 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -65,7 +65,7 @@
 	struct device	dev;
 	struct gendisk	*disk;
 	atomic_t	openers;
-	sector_t	capacity;	/* size in 512-byte sectors */
+	sector_t	capacity;	/* size in logical blocks */
 	u32		max_xfer_blocks;
 	u32		opt_xfer_blocks;
 	u32		max_ws_blocks;
@@ -146,6 +146,11 @@
 	return 0;
 }
 
+static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blocks)
+{
+	return blocks << (ilog2(sdev->sector_size) - 9);
+}
+
 /*
  * A DIF-capable target device can be formatted with different
  * protection schemes.  Currently 0 through 3 are defined: