svn commit: r280299 - in head/release: scripts tools

[Colin Percival]

Author: cperciva
Date: Fri Mar 20 19:40:19 2015
New Revision: 280299
URL: https://svnweb.freebsd.org/changeset/base/280299

Log:
  When creating VM images, copy the contents of the created filesystem into
  a new filesystem before packaging it into a disk image.  This prevents
  "remnants" of deleted files from showing up in the VM images, and reduces
  their compressed size (by about 10% for the cloudware images) as a result.
  
  Looks good to:	gjb

Modified:
  head/release/scripts/mk-vmimage.sh
  head/release/tools/vmimage.subr

Modified: head/release/scripts/mk-vmimage.sh
==============================================================================
--- head/release/scripts/mk-vmimage.sh	Fri Mar 20 19:29:59 2015	(r280298)
+++ head/release/scripts/mk-vmimage.sh	Fri Mar 20 19:40:19 2015	(r280299)
@@ -102,6 +102,7 @@ main() {
 	vm_extra_pre_umount
 	vm_extra_pkg_rmcache
 	cleanup
+	vm_copy_base
 	vm_create_disk || return 0
 	vm_extra_create_disk
 

Modified: head/release/tools/vmimage.subr
==============================================================================
--- head/release/tools/vmimage.subr	Fri Mar 20 19:29:59 2015	(r280298)
+++ head/release/tools/vmimage.subr	Fri Mar 20 19:40:19 2015	(r280299)
@@ -67,6 +67,35 @@ vm_create_base() {
 	return 0
 }
 
+vm_copy_base() {
+	# Creates a new UFS root filesystem and copies the contents of the
+	# current root filesystem into it.  This produces a "clean" disk
+	# image without any remnants of files which were created temporarily
+	# during image-creation and have since been deleted (e.g., downloaded
+	# package archives).
+
+	mkdir -p ${DESTDIR}/old
+	mdold=$(mdconfig -f ${VMBASE})
+	mount /dev/${mdold} ${DESTDIR}/old
+
+	truncate -s ${VMSIZE} ${VMBASE}.tmp
+	mkdir -p ${DESTDIR}/new
+	mdnew=$(mdconfig -f ${VMBASE}.tmp)
+	newfs -j /dev/${mdnew}
+	mount /dev/${mdnew} ${DESTDIR}/new
+
+	tar -cf- -C ${DESTDIR}/old . | tar -xf- -C ${DESTDIR}/new
+
+	umount /dev/${mdold}
+	rmdir ${DESTDIR}/old
+	mdconfig -d -u ${mdold}
+
+	umount /dev/${mdnew}
+	rmdir ${DESTDIR}/new
+	mdconfig -d -u ${mdnew}
+	mv ${VMBASE}.tmp ${VMBASE}
+}
+
 vm_install_base() {
 	# Installs the FreeBSD userland/kernel to the virtual machine disk.