[PATCH v2 4/4] systemd: Apply all sysctl settings through udev rule when NFS-related modules are loaded

From: Salvatore Bonaccorso <carnil@debian.org>
To: NeilBrown <neilb@suse.de>, Steve Dickson <steved@redhat.com>,
	linux-nfs@vger.kernel.org
Cc: Andras Korn <korn-debbugs@elan.rulez.org>,
	Marco d'Itri <md@linux.it>, Michael Prokop <mika@debian.org>,
	Salvatore Bonaccorso <carnil@debian.org>
Subject: [PATCH v2 4/4] systemd: Apply all sysctl settings through udev rule when NFS-related modules are loaded
Date: Fri, 25 Nov 2022 15:06:56 +0100	[thread overview]
Message-ID: <20221125140656.1985137-5-carnil@debian.org> (raw)
In-Reply-To: <20221125140656.1985137-1-carnil@debian.org>

sysctl settings (e.g.  /etc/sysctl.conf and others) are normally loaded
once at boot.  If the module that implements some settings is no yet
loaded, those settings don't get applied.

Various NFS modules support various sysctl settings.  If they are loaded
after boot, they miss out.

Add a new udev rule configuration to udev/rules.d/60-nfs.rules to apply
the relevant settings when the modules are loaded.

Placing it in the systemd directory similarly as the choice for the
original commit afc7132dfb21 ("systemd: Apply all sysctl settings when
NFS-related modules are loaded").

Link: https://lore.kernel.org/linux-nfs/Y1KoKwu88PulcokW@eldamar.lan/
Link: https://bugs.debian.org/1022172
Link: https://bugs.debian.org/1024082
Suggested-by: Marco d'Itri <md@linux.it>
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
---
 systemd/60-nfs.rules | 21 +++++++++++++++++++++
 systemd/Makefile.am  |  9 +++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 systemd/60-nfs.rules

diff --git a/systemd/60-nfs.rules b/systemd/60-nfs.rules
new file mode 100644
index 000000000000..188423c1d2e3
--- /dev/null
+++ b/systemd/60-nfs.rules
@@ -0,0 +1,21 @@
+# Ensure all NFS systctl settings get applied when modules load
+
+# sunrpc module supports "sunrpc.*" sysctls
+ACTION=="add", SUBSYSTEM=="module", KERNEL=="sunrpc", \
+  RUN+="/sbin/sysctl -q --pattern ^sunrpc --system"
+
+# rpcrdma module supports sunrpc.svc_rdma.*
+ACTION=="add", SUBSYSTEM=="module", KERNEL=="rpcrdma", \
+  RUN+="/sbin/sysctl -q --pattern ^sunrpc.svc_rdma --system"
+
+# lockd module supports "fs.nfs.nlm*" and "fs.nfs.nsm*" sysctls
+ACTION=="add", SUBSYSTEM=="module", KERNEL=="lockd", \
+  RUN+="/sbin/sysctl -q --pattern ^fs.nfs.n[sl]m --system"
+
+# nfsv4 module supports "fs.nfs.*" sysctls (nfs_callback_tcpport and idmap_cache_timeout)
+ACTION=="add", SUBSYSTEM=="module", KERNEL=="nfsv4", \
+  RUN+="/sbin/sysctl -q --pattern ^fs.nfs.(nfs_callback_tcpport|idmap_cache_timeout) --system"
+
+# nfs module supports "fs.nfs.*" sysctls
+ACTION=="add", SUBSYSTEM=="module", KERNEL=="nfs", \
+  RUN+="/sbin/sysctl -q --pattern ^fs.nfs --system"
diff --git a/systemd/Makefile.am b/systemd/Makefile.am
index e7f5d818a913..577c6a2286c0 100644
--- a/systemd/Makefile.am
+++ b/systemd/Makefile.am
@@ -2,6 +2,9 @@
 
 MAINTAINERCLEANFILES = Makefile.in
 
+udev_rulesdir = /usr/lib/udev/rules.d/
+udev_files = 60-nfs.rules
+
 unit_files =  \
     nfs-client.target \
     rpc_pipefs.target \
@@ -51,7 +54,7 @@ endif
 
 man5_MANS	= nfs.conf.man
 man7_MANS	= nfs.systemd.man
-EXTRA_DIST = $(unit_files) $(man5_MANS) $(man7_MANS)
+EXTRA_DIST = $(unit_files) $(udev_files) $(man5_MANS) $(man7_MANS)
 
 generator_dir = $(unitdir)/../system-generators
 
@@ -73,8 +76,10 @@ rpc_pipefs_generator_LDADD = ../support/nfs/libnfs.la
 
 if INSTALL_SYSTEMD
 genexec_PROGRAMS = nfs-server-generator rpc-pipefs-generator
-install-data-hook: $(unit_files)
+install-data-hook: $(unit_files) $(udev_files)
 	mkdir -p $(DESTDIR)/$(unitdir)
 	cp $(unit_files) $(DESTDIR)/$(unitdir)
 	cp $(rpc_pipefs_mount_file) $(DESTDIR)/$(unitdir)/$(rpc_pipefsmount)
+	mkdir -p $(DESTDIR)/$(udev_rulesdir)
+	cp $(udev_files) $(DESTDIR)/$(udev_rulesdir)
 endif
-- 
2.38.1

