rc: refactor and simplify crash dump handling

src/etc/rc

@@ -73,10 +73,9 @@ fi
 # set keyboard map if needed
 /etc/rc.d/syscons onestart
 
-# probe for a persistent core dump device
-/usr/local/etc/rc.dumpon
+# set up and recover a crash dump before activating swap
+/usr/local/etc/rc.crashdump
 swapon -a
-/usr/local/etc/rc.savecore
 
 # Remove symlinks that are no longer needed
 if [ -L /etc/dhclient.conf ]; then rm /etc/dhclient.conf; fi

src/etc/rc.crashdump

+#!/bin/sh
+
+echo -n "Configuring crash dump device: "
+
+while read DEV MP TYPE MORE; do
+	[ "${TYPE}" = "swap" ] || continue
+	[ -c "${DEV}" ] || continue
+	if dumpon ${DEV}; then
+		echo ${DEV}
+		if [ -n "`sysctl -Nq debug.ddb.scripting.scripts`" ]; then
+			ddb /usr/local/etc/ddb.conf
+		fi
+		if savecore -C ${DEV} > /dev/null; then
+			savecore /var/crash ${DEV}
+		fi
+		exit 0
+	fi
+done < /etc/fstab
+
+echo "/dev/null"

src/etc/rc.dumpon

-#!/bin/sh
-
-dumpon_try()
-{
-	if /sbin/dumpon "${1}" ; then
-		# Make a symlink in devfs for savecore
-		echo "Using ${1} for dump device."
-		ln -fs "${1}" /dev/dumpdev
-		return 0
-	fi
-	echo "Unable to specify $1 as a dump device."
-	return 1
-}
-
-# Enable dumpdev so that savecore can see it. Enable it
-# early so a crash early in the boot process can be caught.
-#
-while read dev mp type more ; do
-	[ "${type}" = "swap" ] || continue
-	[ -c "${dev}" ] || continue
-	dumpon_try "${dev}" && works=true
-done </etc/fstab
-
-if [ "${works}" != "true" ]; then
-	echo "No suitable dump device was found." 1>&2
-	exit
-fi
-
-# ddb
-if [ ! -z "`sysctl -Nq debug.ddb.scripting.scripts`" ]; then
-	/sbin/ddb /usr/local/etc/ddb.conf
-fi

src/etc/rc.savecore

-#!/bin/sh
-# Based on:
-# FreeBSD: src/etc/rc.d/savecore,v 1.16.2.2.4.1 2010/06/14 02:09:06 kensmith Exp
-
-dumpdev=`/bin/realpath /dev/dumpdev`
-dumpdir='/var/crash'
-
-if [ ! -c "${dumpdev}" ]; then
-	echo "Dump device does not exist.  Savecore not run."
-	exit
-fi
-
-if [ ! -d "${dumpdir}" ]; then
-	echo "Dump directory does not exist.  Savecore not run."
-	exit
-fi
-
-if savecore -C "${dumpdev}" >/dev/null; then
-	savecore ${dumpdir} ${dumpdev}
-else
-	echo 'No core dumps found.'
-fi