unmount real root partition from /mnt before the cgi/random actions

which run asyncronously and can grab vnodes race to make the umount fail
spuriously
problem seen and diagnosed by Yuichiro NAITO
ok florian

diff --git a/distrib/miniroot/install.sub b/distrib/miniroot/install.sub
index 4a8a2e7..f686691 100644 (file)
--- a/distrib/miniroot/install.sub
+++ b/distrib/miniroot/install.sub
@@ -1,5 +1,5 @@
 #!/bin/ksh
-#      $OpenBSD: install.sub,v 1.1184 2021/11/02 16:54:01 kn Exp $
+#      $OpenBSD: install.sub,v 1.1185 2021/12/02 17:18:39 deraadt Exp $
 #
 # Copyright (c) 1997-2015 Todd Miller, Theo de Raadt, Ken Westerback
 # Copyright (c) 2015, Robert Peichaer <rpe@openbsd.org>
@@ -3258,17 +3258,19 @@ do_upgrade() {
        # Configure the network.
        enable_network
 
-       # Fetch list of mirror servers and installer choices from previous runs.
-       start_cgiinfo
-
        # Create a skeletal /etc/fstab which is usable for the upgrade process.
        munge_fstab
 
+       # Do not need to look in /mnt anymore
+       umount /mnt || { echo "Can't umount $ROOTDEV!"; exit; }
+
+       # Fetch list of mirror servers and installer choices from previous runs.
+       start_cgiinfo
+
        # fsck -p non-root filesystems in /etc/fstab.
        check_fs
 
        # Mount filesystems in /etc/fstab.
-       umount /mnt || { echo "Can't umount $ROOTDEV!"; exit; }
        mount_fs
 
        rm -f /mnt/bsd.upgrade /mnt/auto_upgrade.conf