Add pygos specific overlay fs setup

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>

.gitignore

@@ -35,6 +35,9 @@ services/procfs
 services/sysfs
 services/tmpfs
 services/tmpfsrun
+services/tmpfsvar
+services/rootusr
 
 scripts/devfs.sh
+scripts/overlay.sh
 scripts/trymount.sh

Makefile.am

@@ -28,6 +28,8 @@ install-data-local:
 	$(LN_S) $(TEMPLATEDIR)/devfs $(DESTDIR)$(SVCDIR)/devfs
 	$(LN_S) $(TEMPLATEDIR)/tmpfs $(DESTDIR)$(SVCDIR)/tmpfs
 	$(LN_S) $(TEMPLATEDIR)/tmpfsrun $(DESTDIR)$(SVCDIR)/tmpfsrun
+	$(LN_S) $(TEMPLATEDIR)/tmpfsvar $(DESTDIR)$(SVCDIR)/tmpfsvar
+	$(LN_S) $(TEMPLATEDIR)/rootusr $(DESTDIR)$(SVCDIR)/rootusr
 	$(LN_S) $(TEMPLATEDIR)/vfs $(DESTDIR)$(SVCDIR)/vfs
 	$(LN_S) $(TEMPLATEDIR)/shutdown $(DESTDIR)$(SVCDIR)/shutdown
 	$(LN_S) $(TEMPLATEDIR)/reboot $(DESTDIR)$(SVCDIR)/reboot

configure.ac

@@ -34,7 +34,10 @@ AC_CONFIG_FILES([services/devfs])
 AC_CONFIG_FILES([services/procfs])
 AC_CONFIG_FILES([services/tmpfs])
 AC_CONFIG_FILES([services/tmpfsrun])
+AC_CONFIG_FILES([services/tmpfsvar])
+AC_CONFIG_FILES([services/rootusr])
 AC_CONFIG_FILES([scripts/devfs.sh])
+AC_CONFIG_FILES([scripts/overlay.sh])
 AC_CONFIG_FILES([scripts/trymount.sh])
 
 AC_OUTPUT([Makefile])

scripts/Makemodule.am

@@ -1,2 +1,2 @@
 scriptdir = @SCRIPTDIR@
-script_SCRIPTS = scripts/devfs.sh scripts/trymount.sh
+script_SCRIPTS = scripts/devfs.sh scripts/trymount.sh scripts/overlay.sh

scripts/overlay.sh.in

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+lower=/cfg/preserve/${1}
+upper=/cfg/overlay/${1}
+work=/cfg/overlay/${1}_work
+target=${2}
+
+if [ ! -d "$target" ]; then
+	exit
+fi
+
+if [ -d "$lower" ]; then
+	if [ -d "$upper" ]; then
+		@BINPATH@/mkdir -p "$work"
+		@SBINPATH@/mount -t overlay overlay \
+			-olowerdir=${lower},upperdir=${upper},workdir=${work} \
+			${target}
+	else
+		@SBINPATH@/mount --bind "$lower" "$target"
+	fi
+fi

services/Makemodule.am

@@ -4,6 +4,7 @@ init_DATA += services/sysctl services/hwclock services/sysinit
 init_DATA += services/reboot services/shutdown services/sigkill
 init_DATA += services/sigterm services/sync services/devfs
 init_DATA += services/sysfs services/procfs services/tmpfs
-init_DATA += services/tmpfsrun services/vfs
+init_DATA += services/tmpfsrun services/tmpfsvar services/vfs
+init_DATA += services/rootusr
 
 EXTRA_DIST += services/sysinit services/vfs

services/rootusr.in

@@ -0,0 +1,5 @@
+description "mount /root"
+type wait
+target boot
+before vfs
+exec "@SCRIPTDIR@/overlay.sh" root /root

services/tmpfsrun.in

@@ -2,6 +2,7 @@ description "mount /run"
 type wait
 target boot
 before vfs
+after tmpfsvar
 exec "@SBINPATH@/mount" -t tmpfs none /run
 exec "@BINPATH@/mkdir" /run/lock -m 0755
 exec "@BINPATH@/ln" -s /run /var/run

services/tmpfsvar.in

@@ -0,0 +1,10 @@
+description "mount /var"
+type wait
+target boot
+before vfs
+exec "@SBINPATH@/mount" -t tmpfs none /var
+exec "@BINPATH@/mkdir" /var/log -m 0755
+exec "@BINPATH@/mkdir" /var/spool -m 0755
+exec "@BINPATH@/mkdir" /var/lib -m 0755
+exec "@BINPATH@/mkdir" /var/tmp -m 0755
+exec "@SCRIPTDIR@/overlay.sh" var_lib /var/lib