scsi: rescan VPD attributes

The VPD page information might change, so we need to be able to update
it. This patch implements a VPD page rescan whenever the 'rescan' sysfs
attribute is triggered.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index fe89d7c..bde4077 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -109,6 +109,7 @@
 	char type;
 	char scsi_level;
 	char inq_periph_qual;	/* PQ from INQUIRY data */	
+	struct mutex inquiry_mutex;
 	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
 	unsigned char * inquiry;	/* INQUIRY response data */
 	const char * vendor;		/* [back_compat] point into 'inquiry' ... */
@@ -117,9 +118,9 @@
 
 #define SCSI_VPD_PG_LEN                255
 	int vpd_pg83_len;
-	unsigned char *vpd_pg83;
+	unsigned char __rcu *vpd_pg83;
 	int vpd_pg80_len;
-	unsigned char *vpd_pg80;
+	unsigned char __rcu *vpd_pg80;
 	unsigned char current_tag;	/* current tag */
 	struct scsi_target      *sdev_target;   /* used only for single_lun */