vdev_id: extension for new scsi topology

On systems with SCSI rather than SAS disk topology, this change enables
the vdev_id script to match against the block device path, and therefore
create a vdev alias in /dev/disk/by-vdev.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Simon Guest <simon.guest@tesujimath.org>
Closes #6592

etc/zfs/Makefile.am

@@ -4,6 +4,7 @@ pkgsysconf_DATA = \
 	vdev_id.conf.alias.example \
 	vdev_id.conf.sas_direct.example \
 	vdev_id.conf.sas_switch.example \
-	vdev_id.conf.multipath.example
+	vdev_id.conf.multipath.example \
+	vdev_id.conf.scsi.example
 
 EXTRA_DIST = $(pkgsysconf_DATA)

etc/zfs/vdev_id.conf.scsi.example

@@ -0,0 +1,9 @@
+multipath     no
+topology      scsi
+phys_per_port 1
+# Usually scsi disks are numbered from 0, but this can be offset, to
+# match the physical bay numbers, as follows:
+first_bay_number 1
+
+#       PCI_ID  HBA PORT  CHANNEL NAME
+channel 0c:00.0 0         Y