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

1 files changed, 29 insertions, 0 deletions

diff --git a/etc/rc.d/hostid_save b/etc/rc.d/hostid_save
new file mode 100755
index 0000000..44e403f
--- /dev/null
+++ b/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"