* Instead of using umount -f to unmount things, first use fstat to

look for processes holding open references within the FS and kill
them, then use regular umount.  This is necessary now that devfs
cannot be force-unmounted, and has the benefit that processes can't
hang around holding references to files between port builds.

* Reduce possibility for error by testing for presence of executable
ldconfig inside the chroot before attempting to run it (e.g. it may not
be there if the chroot was not completely initialized)

Tools/portbuild/scripts/clean-chroot

@@ -1,5 +1,37 @@
 #!/bin/sh
 
+kill_procs()
+{
+  dir=$1
+
+  pids="XXX"
+  while [ ! -z "${pids}" ]; do
+    pids=$(fstat -f "$dir" | tail +2 | awk '{print $3}' | sort -u)
+    if [ ! -z "${pids}" ]; then
+      echo "Killing off pids in ${dir}"
+      ps -p $pids
+      kill -KILL ${pids} 2> /dev/null
+      sleep 2
+    fi
+  done
+}
+
+cleanup_mount() {
+  chroot=$1
+  mount=$2
+
+  if [ -d ${chroot}${mount} ]; then
+    mdir=$(fstat -f ${chroot}${mount} | head -2 | tail -1 | awk '{print $5}')
+    if [ "${mdir}" = "MOUNT" ]; then
+      umount ${chroot}${mount} || echo "Cleanup of ${chroot}${mount} failed!"
+    fi
+    if [ "${mdir}" = "${chroot}${mount}" ]; then
+      kill_procs ${chroot}${mount}
+      umount ${chroot}${mount} || echo "Cleanup of ${chroot}${mount} failed!" 
+    fi
+  fi
+}
+
 arch=$1
 branch=$2
 chroot=$3
@@ -8,6 +40,10 @@ noclean=$4
 # directories to clean
 cleandirs="/usr/local /usr/X11R6 /compat /var/db/pkg"
 
+if [ ! -d "${chroot}" ]; then
+  exit 0
+fi
+
 if [ `realpath ${chroot}` = "/" ]; then
   # Don't spam the root file system if something has gone wrong!
   exit 1
@@ -16,13 +52,14 @@ fi
 #umount ${chroot}/proc
 
 if [ ${arch} = "i386" ]; then
-  chroot ${chroot} umount -f /compat/linux/proc
+  cleanup_mount ${chroot} /compat/linux/proc
 fi
+  
+for i in /a/ports /usr/opt/doc /usr/src /dev; do
+  cleanup_mount ${chroot} ${i}
+done
 
-umount -f ${chroot}/a/ports 2> /dev/null
-umount -f ${chroot}/usr/opt/doc 2> /dev/null
-umount -f ${chroot}/usr/src 2> /dev/null
-umount -f ${chroot}/dev 2> /dev/null
+#kill_procs ${chroot}
 
 if [ $noclean = 0 ]; then
   rm -rf ${chroot}/tmp/*
@@ -32,9 +69,9 @@ if [ $noclean = 0 ]; then
       rm -rf ${chroot}${dir} >/dev/null 2>&1
     fi
   done
-  chroot ${chroot} /sbin/ldconfig -R
+  test -x ${chroot}/sbin/ldconfig && chroot ${chroot} /sbin/ldconfig -R
   if [ ${arch} = "i386" ]; then
-	chroot ${chroot} /sbin/ldconfig -aout -R
+	test -x ${chroot}/sbin/ldconfig && chroot ${chroot} /sbin/ldconfig -aout -R
   fi
   rm -rf ${chroot}/var/db/pkg/*
   rm -rf ${chroot}/used