Rather than ordering systemd-random-seed-load.service after local-fs.target,
start it by path-activation.

We need write access to the seed, so we order the path unit after
remount-rootfs.service (in case /var is on the root fs).

A better solution might be to introduce PathIsWritable=, but that is not
necessary in order to solve the problem, and I don't know of any other
usecases for it.

Cc: Frederic Crozat <fcrozat@suse.com>
Cc: Michal Schmidt <mschmidt@redhat.com>
---

This is my second attempt at solving this problem. The first one had
some issues as pointed out by Frederic and Michael.

 Makefile.am                               |    7 +++++--
 TODO                                      |    2 --
 units/.gitignore                          |    1 +
 units/systemd-random-seed-load.path.in    |   18 ++++++++++++++++++
 units/systemd-random-seed-load.service.in |    3 +--
 5 files changed, 25 insertions(+), 6 deletions(-)
 create mode 100644 units/systemd-random-seed-load.path.in

diff -urB systemd-38/Makefile.am new/Makefile.am
--- systemd-38/Makefile.am	2012-01-11 04:01:36.734404653 +0100
+++ new/Makefile.am	2012-01-18 09:53:12.763115731 +0100
@@ -1530,11 +1530,14 @@
 
 nodist_systemunit_DATA += \
 	units/systemd-random-seed-save.service \
-	units/systemd-random-seed-load.service
+	units/systemd-random-seed-load.service \
+	units/systemd-random-seed-load.path
+
 
 EXTRA_DIST += \
 	units/systemd-random-seed-save.service.in \
-	units/systemd-random-seed-load.service.in
+	units/systemd-random-seed-load.service.in \
+        units/systemd-random-seed-load.path.in
 
 systemd_random_seed_SOURCES = \
 	src/random-seed.c
@@ -1550,8 +1553,8 @@
 		rm -f systemd-random-seed-save.service && \
 		$(LN_S) ../systemd-random-seed-save.service systemd-random-seed-save.service )
 	( cd $(DESTDIR)$(systemunitdir)/sysinit.target.wants && \
-		rm -f systemd-random-seed-load.service && \
-		$(LN_S) ../systemd-random-seed-load.service systemd-random-seed-load.service )
+		rm -f systemd-random-seed-load.path && \
+		$(LN_S) ../systemd-random-seed-load.path systemd-random-seed-load.path )
 
 INSTALL_DATA_HOOKS += \
 	randomseed-install-data-hook
@@ -2052,6 +2055,7 @@
 		-e 's,@exec_prefix\@,$(exec_prefix),g' \
 		-e 's,@libdir\@,$(libdir),g' \
 		-e 's,@includedir\@,$(includedir),g' \
+		-e 's,@localstatedir\@,$(localstatedir),g' \
 		< $< > $@ || rm $@
 
 units/%: units/%.in Makefile
diff --git a/units/systemd-random-seed-load.path.in b/units/systemd-random-seed-load.path.in
new file mode 100644
index 0000000..614c1d4
--- /dev/null
+++ b/units/systemd-random-seed-load.path.in
@@ -0,0 +1,18 @@
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Random Seed
+DefaultDependencies=no
+Conflicts=shutdown.target
+Before=basic.target shutdown.target
+# in case the seed is on the rootfs, we must
+# wait for the rootfs to be remonuted rw
+After=remount-rootfs.service
+
+[Path]
+PathExists=@localstatedir@/lib/random-seed
diff --git a/units/systemd-random-seed-load.service.in b/units/systemd-random-seed-load.service.in
index a2b6a55..2bcf1aa 100644
--- a/units/systemd-random-seed-load.service.in
+++ b/units/systemd-random-seed-load.service.in
@@ -8,9 +8,8 @@
 [Unit]
 Description=Load Random Seed
 DefaultDependencies=no
-Wants=local-fs.target
 Conflicts=shutdown.target
-After=systemd-readahead-collect.service systemd-readahead-replay.service local-fs.target
+After=systemd-readahead-collect.service systemd-readahead-replay.service systemd-random-seed-load.path
 Before=sysinit.target shutdown.target
 
 [Service]
-- 
1.7.8