rc: awareness for crash dumps on /var MFS, closes #874

(cherry picked from commit 66f0288a)

src/etc/rc

@@ -70,10 +70,6 @@ fi
 # set keyboard map if needed
 /etc/rc.d/syscons onestart
 
-# set up and recover a crash dump before activating swap
-/usr/local/etc/rc.crashdump
-swapon -a
-
 # set up config directory structure
 mkdir -p /conf/backup
 mkdir -p /conf/sshd
@@ -129,30 +125,52 @@ if [ ${USE_MFS_TMPVAR} -ne 0 ]; then
 		ln -s /root/var/db/pkg /var/db/pkg
 	fi
 
+	if [ ! -d /root/var/crash ]; then
+		mkdir -p /root/var
+		mv /var/crash /root/var
+		ln -s /root/var/crash /var/crash
+	fi
+
 	mount -t tmpfs -o mode=01777 tmpfs /tmp
 	mount -t tmpfs tmpfs /var
 
 	mkdir -p /var/db
 	ln -s /root/var/db/pkg /var/db/pkg
 
+	mkdir -p /var
+	ln -s /root/var/crash /var/crash
+
 	echo "done."
-elif [ -d /root/var/db/pkg ]; then
+else
 	# User must have just disabled RAM disks,
 	# let's move these back into place.
+
+	if [ -d /root/var/db/pkg ]; then
 		mkdir -p /var/db
 		# reverse the recovery symlink before moving
 		# back the original database:
 		rm -f /var/db/pkg
 		mv /root/var/db/pkg /var/db/
+	fi
+
+	if [ -d /root/var/crash ]; then
+		mkdir -p /var
+		rm -f /var/crash
+		mv /root/var/crash /var/crash
+	fi
 fi
 
 # make some directories in /var
 mkdir -p /var/run /var/log /var/etc /var/db/entropy /var/at/jobs \
-    /var/empty /var/tmp
+    /var/empty /var/tmp /var/crash
 
 # work around the fact that shutdown(8) doesn't clean up this file
 rm -f /var/run/nologin
 
+# set up and recover a crash dump before activating swap
+/usr/local/etc/rc.crashdump
+swapon -a
+
 # write /var/run/dmesg.boot
 /etc/rc.d/dmesg onestart