[ndctl,v3,10/11] daxctl: add systemd service and udev rule for automatic reconfiguration

Commit Message

Verma, Vishal L Dec. 10, 2021, 10:34 p.m. UTC

Install a systemd service that calls "daxctl-reconfigure-device
--check-config"  with a daxctl device passed in to it via the
environment.

Install a udev rule that is triggered for every daxctl device, and
triggers the above oneshot systemd service.

On boot, whenever a daxctl device is found, udev triggers a
device-specific systemd service called, for example:

  [e-mail]

This initiates a daxctl-reconfigure-device with a config lookup for the
'dax0.0' device. If the config has a '[reconfigure-device <unique_id>]'
section, it uses the information in that to set the operating mode of
the device.

If any device is in an unexpected status, 'journalctl' can be used to
view the reconfiguration log for that device, for example:

  journalctl --unit [e-mail]

Update the RPM spec file to include the newly added files to the RPM
build.

Cc: QI Fuli <[e-mail]>
Cc: Dan Williams <[e-mail]>
Signed-off-by: Vishal Verma <[e-mail]>
---
 configure.ac                       | 9 ++++++++-
 daxctl/90-daxctl-device.rules      | 1 +
 daxctl/Makefile.am                 | 7 +++++++
 daxctl/daxdev-reconfigure@.service | 8 ++++++++
 ndctl.spec.in                      | 3 +++
 5 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 daxctl/90-daxctl-device.rules
 create mode 100644 daxctl/daxdev-reconfigure@.service

Comments

Dan Williams Dec. 16, 2021, 11:03 p.m. UTC | #1

On Fri, Dec 10, 2021 at 2:34 PM Vishal Verma <[e-mail]> wrote:
>
> Install a systemd service that calls "daxctl-reconfigure-device
> --check-config"  with a daxctl device passed in to it via the
> environment.
>
> Install a udev rule that is triggered for every daxctl device, and
> triggers the above oneshot systemd service.
>
> On boot, whenever a daxctl device is found, udev triggers a
> device-specific systemd service called, for example:
>
>   [e-mail]
>
> This initiates a daxctl-reconfigure-device with a config lookup for the
> 'dax0.0' device. If the config has a '[reconfigure-device <unique_id>]'
> section, it uses the information in that to set the operating mode of
> the device.
>
> If any device is in an unexpected status, 'journalctl' can be used to
> view the reconfiguration log for that device, for example:
>
>   journalctl --unit [e-mail]
>
> Update the RPM spec file to include the newly added files to the RPM
> build.
>
> Cc: QI Fuli <[e-mail]>
> Cc: Dan Williams <[e-mail]>
> Signed-off-by: Vishal Verma <[e-mail]>

LGTM. I don't know if udev rule numbering is correct, or not, but I
suspect the distros will tell us or fix it up in the distro package.

Reviewed-by: Dan Williams <[e-mail]>

Patch

diff --git a/configure.ac b/configure.ac
index 39ad0d4..33cff60 100644
--- a/configure.ac
+++ b/configure.ac
@@ -160,7 +160,7 @@  AC_CHECK_FUNCS([ \
 
 AC_ARG_WITH([systemd],
 	AS_HELP_STRING([--with-systemd],
-		[Enable systemd functionality (monitor). @<:@default=yes@:>@]),
+		[Enable systemd functionality. @<:@default=yes@:>@]),
 	[], [with_systemd=yes])
 
 if test "x$with_systemd" = "xyes"; then
@@ -186,6 +186,13 @@  daxctl_modprobe_data=daxctl.conf
 AC_SUBST([daxctl_modprobe_datadir])
 AC_SUBST([daxctl_modprobe_data])
 
+AC_ARG_WITH(udevrulesdir,
+    [AS_HELP_STRING([--with-udevrulesdir=DIR], [udev rules.d directory])],
+    [UDEVRULESDIR="$withval"],
+    [UDEVRULESDIR='${prefix}/lib/udev/rules.d']
+)
+AC_SUBST(UDEVRULESDIR)
+
 AC_ARG_WITH([keyutils],
 	    AS_HELP_STRING([--with-keyutils],
 			[Enable keyutils functionality (security).  @<:@default=yes@:>@]), [], [with_keyutils=yes])
diff --git a/daxctl/90-daxctl-device.rules b/daxctl/90-daxctl-device.rules
new file mode 100644
index 0000000..ee0670f
--- /dev/null
+++ b/daxctl/90-daxctl-device.rules
@@ -0,0 +1 @@ 
+ACTION=="add", SUBSYSTEM=="dax", TAG+="systemd", ENV{SYSTEMD_WANTS}="daxdev-reconfigure@$env{DEVNAME}.service"
diff --git a/daxctl/Makefile.am b/daxctl/Makefile.am
index 5cebb6c..36dfc55 100644
--- a/daxctl/Makefile.am
+++ b/daxctl/Makefile.am
@@ -28,3 +28,10 @@  daxctl_LDADD =\
 	$(KMOD_LIBS) \
 	$(JSON_LIBS) \
 	-liniparser
+
+udevrulesdir = $(UDEVRULESDIR)
+udevrules_DATA = 90-daxctl-device.rules
+
+if ENABLE_SYSTEMD_UNITS
+systemd_unit_DATA = daxdev-reconfigure@.service
+endif
diff --git a/daxctl/daxdev-reconfigure@.service b/daxctl/daxdev-reconfigure@.service
new file mode 100644
index 0000000..13d570c
--- /dev/null
+++ b/daxctl/daxdev-reconfigure@.service
@@ -0,0 +1,8 @@ 
+[Unit]
+Description=Automatic daxctl device reconfiguration
+Documentation=man:daxctl-reconfigure-device(1)
+
+[Service]
+Type=forking
+GuessMainPID=false
+ExecStart=/bin/sh -c "exec daxctl reconfigure-device --check-config %I"
diff --git a/ndctl.spec.in b/ndctl.spec.in
index b46bd74..642670a 100644
--- a/ndctl.spec.in
+++ b/ndctl.spec.in
@@ -26,6 +26,7 @@  BuildRequires:	pkgconfig(json-c)
 BuildRequires:	pkgconfig(bash-completion)
 BuildRequires:	pkgconfig(systemd)
 BuildRequires:	keyutils-libs-devel
+BuildRequires:	systemd-rpm-macros
 
 %description
 Utility library for managing the "libnvdimm" subsystem.  The "libnvdimm"
@@ -126,6 +127,8 @@  make check
 %{_bindir}/daxctl
 %{_mandir}/man1/daxctl*
 %{_datadir}/daxctl/daxctl.conf
+%{_unitdir}/daxdev-reconfigure@.service
+%config %{_udevrulesdir}/90-daxctl-device.rules
 
 %files -n LNAME
 %defattr(-,root,root)