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From:   Alberto Garcia <berto@igalia.com>
To:     linux-nfs@vger.kernel.org
Cc:     Alberto Garcia <berto@igalia.com>
Subject: [PATCH] systemd: Ensure that statdpath exists using systemd-tmpfiles
Date:   Thu, 13 Jul 2023 12:25:31 +0200
Message-Id: <20230713102531.131072-1-berto@igalia.com>
MIME-Version: 1.0
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The NFS utils store their state under /var/lib/nfs and they can
generally handle the case where that directory is missing by creating
the appropriate files and directories automatically.

This is not the case of rpc-statd: if sm and sm.bak (under $statdpath,
which also defaults to /var/lib/nfs) are missing the daemon will
refuse to start and will exit with an error.

If nfs-utils is configured with systemd support it can take advantage
of systemd-tmpfiles to ensure that the state directories are always
present and have the appropriate ownership.

This would normally be handled with the StateDirectory directive in
rpc-statd.service, however that method would not be able to change the
ownership of the directories to $statduser because this daemon needs
to be run as root, and only later changes its uid and gid.

Signed-off-by: Alberto Garcia <berto@igalia.com>
---
 configure.ac              | 1 +
 systemd/Makefile.am       | 5 +++++
 systemd/nfs-utils.conf.in | 4 ++++
 3 files changed, 10 insertions(+)
 create mode 100644 systemd/nfs-utils.conf.in

diff --git a/configure.ac b/configure.ac
index 6fbcb974..fe958ab3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -695,6 +695,7 @@ AC_CONFIG_COMMANDS_PRE([eval eval _rpc_pipefsmount=$rpc_pipefsmount])
 
 AC_CONFIG_FILES([
 	Makefile
+	systemd/nfs-utils.conf
 	systemd/rpc-gssd.service
 	systemd/rpc_pipefs.target
 	systemd/var-lib-nfs-rpc_pipefs.mount
diff --git a/systemd/Makefile.am b/systemd/Makefile.am
index b4483222..6127986e 100644
--- a/systemd/Makefile.am
+++ b/systemd/Makefile.am
@@ -5,6 +5,9 @@ MAINTAINERCLEANFILES = Makefile.in
 udev_rulesdir = /usr/lib/udev/rules.d/
 udev_files = 60-nfs.rules
 
+sdtmpfilesdir = /usr/lib/tmpfiles.d/
+sdtmpfiles_files = nfs-utils.conf
+
 unit_files =  \
     nfs-client.target \
     rpc_pipefs.target \
@@ -85,4 +88,6 @@ install-data-hook: $(unit_files) $(udev_files)
 	cp $(rpc_pipefs_mount_file) $(DESTDIR)/$(unitdir)/$(rpc_pipefsmount)
 	mkdir -p $(DESTDIR)/$(udev_rulesdir)
 	cp $(udev_files) $(DESTDIR)/$(udev_rulesdir)
+	mkdir -p $(DESTDIR)/$(sdtmpfilesdir)
+	cp $(sdtmpfiles_files) $(DESTDIR)/$(sdtmpfilesdir)
 endif
diff --git a/systemd/nfs-utils.conf.in b/systemd/nfs-utils.conf.in
new file mode 100644
index 00000000..a44c337e
--- /dev/null
+++ b/systemd/nfs-utils.conf.in
@@ -0,0 +1,4 @@
+# This is a systemd-tmpfiles configuration file
+# type path			mode	uid	gid	age	argument
+d      @statdpath@/sm		0700	@statduser@	:root	-       -
+d      @statdpath@/sm.bak	0700	@statduser@	:root	-	-
-- 
2.39.2