Currently there is a problem with fscking UFS file systems created on

top of ZVOLs. The problem is that rc.d/fsck runs before rc.d/zfs. The
latter makes ZVOLs to appear in /dev/. In such case rc.d/fsck cannot
find devfs entry and aborts. We cannot simply move rc.d/zfs before
rc.d/fsck, because we first want kern.hostid to be configured (by
rc.d/hostid). If we won't wait (hostid will be 0) we can reuse disks
which are in use by different systems (eg. in SAN/NAS environment).
We also cannot move rc.d/hostid before rc.d/fsck, because rc.d/hostid on
first system start stores generated kern.hostuuid in /etc/hostid file,
so it needs root file system to be mounted read-write.

The fix is to split rc.d/hostid so that rc.d/hostid (which will now run
before rc.d/fsck) only generates hostid and sets up sysctls, but doesn't
touch root file system and rc.d/hostid_save (which is run after
rc.d/root) and only creates /etc/hostid file.

With that in place, we can move ZVOL initialization to dedicated
rc.d/zvol script which runs before rc.d/fsck.

PR:		conf/120194
Reported by:	James Snow <snow@teardrop.org>
Reviewed by:	brooks
Approved by:	re (kib)
MFC after:	2 weeks

etc/rc.d/Makefile

@@ -13,7 +13,7 @@ FILES=	DAEMON FILESYSTEMS LOGIN NETWORKING SERVERS \
 	fsck ftp-proxy ftpd \
 	gbde geli geli2 gssd \
 	hcsecd \
-	hostapd hostid hostname \
+	hostapd hostid hostid_save hostname \
 	inetd initrandom \
 	ip6addrctl ip6fw ipfilter ipfs ipfw ipmon \
 	ipnat ipsec ipxrouted \
@@ -40,7 +40,7 @@ FILES=	DAEMON FILESYSTEMS LOGIN NETWORKING SERVERS \
 	watchdogd wpa_supplicant \
 	ypbind yppasswdd ypserv \
 	ypset ypupdated ypxfrd \
-	zfs
+	zfs zvol
 
 .if ${MK_OPENSSH} != "no"
 FILES+=	sshd

etc/rc.d/hostid

@@ -28,8 +28,7 @@
 #
 
 # PROVIDE: hostid
-# REQUIRE: root
+# BEFORE: fsck
-# BEFORE: mountcritlocal
 # KEYWORD: nojail
 
 . /etc/rc.subr
@@ -68,7 +67,7 @@ hostid_hardware()
 	esac
 }
 
-hostid_reset()
+hostid_generate()
 {
 	# First look for UUID in hardware.
 	uuid=`hostid_hardware`
@@ -76,12 +75,17 @@ hostid_reset()
 		# If not found, fall back to software-generated UUID.
 		uuid=`uuidgen`
 	fi
+	hostid_set $uuid
+}
+
+hostid_reset()
+{
+	hostid_generate
 	# Store newly generated UUID in ${hostid_file}.
 	echo $uuid > ${hostid_file}
 	if [ $? -ne 0 ]; then
 		warn "could not store hostuuid in ${hostid_file}."
 	fi
-	hostid_set $uuid
 }
 
 hostid_start()
@@ -91,7 +95,7 @@ hostid_start()
 		hostid_set `cat ${hostid_file}`
 	else
 		# No hostid file, generate UUID.
-		hostid_reset
+		hostid_generate
 	fi
 }
 

etc/rc.d/hostid_save

@@ -0,0 +1,29 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: hostid_save
+# REQUIRE: root
+# BEFORE: mountcritlocal
+# KEYWORD: nojail
+
+. /etc/rc.subr
+
+name="hostid_save"
+start_cmd="hostid_save"
+stop_cmd=":"
+rcvar="hostid_enable"
+
+hostid_save()
+{
+	if [ ! -r ${hostid_file} ]; then
+		$SYSCTL_N kern.hostuuid > ${hostid_file}
+		if [ $? -ne 0 ]; then
+			warn "could not store hostuuid in ${hostid_file}."
+		fi
+	fi
+}
+
+load_rc_config $name
+run_rc_command "$1"

etc/rc.d/zfs

@@ -23,21 +23,11 @@ zfs_start_jail()
 
 zfs_start_main()
 {
-	zfs volinit
 	zfs mount -a
 	zfs share -a
 	if [ ! -r /etc/zfs/exports ]; then
 		touch /etc/zfs/exports
 	fi
-	# Enable swap on ZVOLs with property org.freebsd:swap=on.
-	zfs list -H -o org.freebsd:swap,name -t volume | \
-	while read state name; do
-		case "${state}" in
-		[oO][nN])
-			swapon /dev/zvol/${name}
-			;;
-		esac
-	done
 }
 
 zfs_start()
@@ -58,18 +48,8 @@ zfs_stop_jail()
 
 zfs_stop_main()
 {
-	# Disable swap on ZVOLs with property org.freebsd:swap=on.
-	zfs list -H -o org.freebsd:swap,name -t volume | \
-	while read state name; do
-		case "${state}" in
-		[oO][nN])
-			swapoff /dev/zvol/${name}
-			;;
-		esac
-	done
 	zfs unshare -a
 	zfs unmount -a
-	zfs volfini
 }
 
 zfs_stop()

etc/rc.d/zvol

@@ -0,0 +1,48 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: zvol
+# REQUIRE: hostid
+# BEFORE: fsck
+# KEYWORD: nojail
+
+. /etc/rc.subr
+
+name="zvol"
+rcvar="zfs_enable"
+start_cmd="zvol_start"
+stop_cmd="zvol_stop"
+required_modules="zfs"
+
+zvol_start()
+{
+	zfs volinit
+	# Enable swap on ZVOLs with property org.freebsd:swap=on.
+	zfs list -H -o org.freebsd:swap,name -t volume | \
+	while read state name; do
+		case "${state}" in
+		[oO][nN])
+			swapon /dev/zvol/${name}
+			;;
+		esac
+	done
+}
+
+zvol_stop()
+{
+	# Disable swap on ZVOLs with property org.freebsd:swap=on.
+	zfs list -H -o org.freebsd:swap,name -t volume | \
+	while read state name; do
+		case "${state}" in
+		[oO][nN])
+			swapoff /dev/zvol/${name}
+			;;
+		esac
+	done
+	zfs volfini
+}
+
+load_rc_config $name
+run_rc_command "$1"