Bring up multipath devices that are configured in multipath.conf.

This brings up multipath devices which are configured in multipath.conf
as we find them.

modules.d/90multipath/14-multipath-scan.rules

@@ -0,0 +1,9 @@
+# scan for multipath devices
+SUBSYSTEM!="block", GOTO="end_mpath_scan"
+KERNEL!="sd*", GOTO="end_mpath_scan"
+PROGRAM=="/bin/sh -c 'for i in //holders/dm-[0-9]*; do [ -e $$i ] && exit 0; done; exit 1;' ", GOTO="end_mpath_scan"
+RUN+="/sbin/modprobe dm-multipath"
+RUN+="/bin/echo 'queuing multipath scan'"
+RUN+="/sbin/initqueue --settled --onetime --unique --name=mpscan /sbin/multipath-scan"
+RUN+="/bin/sh -c '>/tmp/.multipath-scan-%k;'"
+LABEL="end_mpath_scan"

modules.d/90multipath/install

@@ -27,3 +27,6 @@ done
 inst_hook pre-trigger 02 "$moddir/multipathd.sh"
 inst_hook pre-pivot   02 "$moddir/multipathd-stop.sh"
 inst_rules 40-multipath.rules
+
+inst "$moddir/multipath-scan.sh" /sbin/multipath-scan
+inst_rules "$moddir/14-multipath-scan.rules"

modules.d/90multipath/multipath-scan.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+# scan for multipaths if udev has settled
+
+. /lib/dracut-lib.sh
+
+[ -d /etc/multipath ] || mkdir -p /etc/multipath
+mpdevs=$(
+    for f in /tmp/.multipath-scan-* ; do
+        [ -e "$f" ] || continue
+        echo -n "${f##/tmp/.multipath-scan-} "
+    done
+)
+
+[ -e /etc/multipath.conf ] || exit 1
+multipath ${mpdevs}