* 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.

* Preliminary work to support using ccache to accelerate builds.

Tools/portbuild/scripts/portbuild

@@ -34,6 +34,38 @@ copypkg()
     fi
 }
 
+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
+}
+
 cleanup()
 {
   chroot=$1
@@ -46,13 +78,14 @@ cleanup()
 
   echo ARCH=${arch}
   if [ ${arch} = "i386" ]; then
-    umount -f ${chroot}/compat/linux/proc
+    cleanup_mount ${chroot} /compat/linux/proc
   fi
 
-  umount -f ${chroot}/a/ports
-  umount -f ${chroot}/usr/opt/doc
-  umount -f ${chroot}/usr/src
-  umount -f ${chroot}/dev
+  cleanup_mount ${chroot} /a/ports
+  cleanup_mount ${chroot} /usr/opt/doc
+  cleanup_mount ${chroot} /usr/src
+  cleanup_mount ${chroot} /dev
+  test -d ${chroot}/root/.ccache && cleanup_mount ${chroot} /root/.ccache
 
   if [ $noclean = 0 -o $error = 0 ]; then
     rm -rf ${chroot}/tmp/*
@@ -239,6 +272,11 @@ echo "in directory ${chroot}" | tee -a ${chroot}/tmp/${pkgname}.log
 mkdir -p ${chroot}/a/ports
 rm -rf ${chroot}/usr/ports
 
+if [ ! -z "${ccache_dir}" ]; then
+  mkdir -p ${chroot}/root/.ccache/
+  mount -o rw -t nullfs ${ccache_dir} ${chroot}/root/.ccache/
+fi
+
 mount_fs ${pb}/${arch}/${branch}/ports ${chroot}/a/ports ${master}
 ln -sf ../a/ports ${chroot}/usr/ports
 
@@ -249,7 +287,7 @@ mount_fs ${pb}/${arch}/${branch}/doc ${chroot}/usr/opt/doc ${master}
 
 mount -t devfs foo ${chroot}/dev
 
-umount -f ${chroot}/compat/linux/dev > /dev/null 2>&1
+umount -f ${chroot}/compat/linux/proc > /dev/null 2>&1
 
 # just in case...
 for dir in ${cleandirs}; do