[PATCH rfc 6/6] nvme-cli: nvmf auto-connect scripts

[jsmart2021@gmail.com (James Smart)]

This set of scripts is a combination of those sent by Hannes, Sagi,
and I in earlier patches and RFC's.

Auto-connect operates by the nvme core layer or nvme-fc transport
generating a udev event with directory-controller addressing
information. The nvme core layer generates an event when a
persistent discovery controller generates a Discovery Log Change
Notification AEN.  The nvme-fc transport generates an event when
an FC rport that has a NVME Discovery controller is detected or
when a FC state change event occurs for for an FC rport that has
a NVME Discovery controller

The udev event is handled by a script that extracts the Discovery
controller addressing information and initiates a systemd service
to perform a "nvme connect-all" to the Discovery controller.
The "nvme connect-all" request is not called directly from the udev
handler itself as the request may take some time or stall altogether,
which would block other udev event handling.  By transitioning to
a sytemd service, the call can take as much time as needed to
complete.

The scripts consist of:
- A udev script that handles nvme core and nvme-fc udev events.
  The udev handler starts a nvmf-connect systemd service.
- A nvmf-connect systemd service. The service, in its instance
  name, is passed the connect arguments for the discovery
  controller. The service performs a "nvme connect-all" to the
  discovery controller.
- A nvmefc-boot-connections systemd service. This is a run-once
  service run after udev is enabled, which will replay events
  generated by NVME-FC devices detected during boot while udev
  is not yet running.
- To stop autoconnect an additional nvmefc-connect.target has
  been added, which will instruct systemd to cancel all
  outstanding autoconnect services.

Note: Although the nvme-fc subsystem is converting to use the
  same nvme core layer event mechanism, the nvme-fc-specific
  udev event that has been in existence for a while is contained
  in in the script so that the utilities may run against older
  kernels.

Signed-off-by: James Smart <jsmart2021 at gmail.com>
CC: Simon Schricker <sschricker at suse.com>
Reviewed-by: Hannes Reinecke <hare at suse.com>
CC: Sagi Grimberg <sagi at grimberg.me>

---
Added install lines for 70-nvmf-autoconnect.conf and nvmf-connect.target
Revised Makefile to set/use LIBDIR. Hardset to /usr/lib to match the
  nvme.spec.in file
Revised nvme.spec.in to use %{_libdir}
Added --quiet option udev scripts that specify nvme connect-all args
---
 Makefile                                         | 16 ++++++++++++++--
 nvme.spec.in                                     |  9 +++++++++
 nvmf-autoconnect/70-nvmf-autoconnect.conf        |  1 +
 nvmf-autoconnect/70-nvmf-autoconnect.rules       | 18 ++++++++++++++++++
 nvmf-autoconnect/nvmefc-boot-connections.service |  9 +++++++++
 nvmf-autoconnect/nvmf-connect.target             |  2 ++
 nvmf-autoconnect/nvmf-connect at .service           | 14 ++++++++++++++
 7 files changed, 67 insertions(+), 2 deletions(-)
 create mode 100644 nvmf-autoconnect/70-nvmf-autoconnect.conf
 create mode 100644 nvmf-autoconnect/70-nvmf-autoconnect.rules
 create mode 100644 nvmf-autoconnect/nvmefc-boot-connections.service
 create mode 100644 nvmf-autoconnect/nvmf-connect.target
 create mode 100644 nvmf-autoconnect/nvmf-connect at .service

diff --git a/Makefile b/Makefile
index ebb6b75..0389497 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,10 @@ DESTDIR =
 PREFIX ?= /usr/local
 SYSCONFDIR = /etc
 SBINDIR = $(PREFIX)/sbin
+LIBDIR ?= /usr/lib
+SYSTEMDDIR ?= $(LIBDIR)/systemd
+UDEVDIR ?= $(LIBDIR)/udev
+DRACUTDIR ?= $(LIBDIR)/dracut
 LIB_DEPENDS =
 
 ifeq ($(LIBUUID),0)
@@ -87,6 +91,14 @@ install-bash-completion:
 	$(INSTALL) -d $(DESTDIR)$(PREFIX)/share/bash-completion/completions
 	$(INSTALL) -m 644 -T ./completions/bash-nvme-completion.sh $(DESTDIR)$(PREFIX)/share/bash-completion/completions/nvme
 
+install-udev:
+	$(INSTALL) -d $(DESTDIR)$(SYSTEMDDIR)/system
+	$(INSTALL) -m 644 ./nvmf-autoconnect/*.service ./nvmf-autoconnect/*.target $(DESTDIR)$(SYSTEMDDIR)/system
+	$(INSTALL) -d $(DESTDIR)$(UDEVDIR)/rules.d
+	$(INSTALL) -m 644 ./nvmf-autoconnect/*.rules $(DESTDIR)$(UDEVDIR)/rules.d
+	$(INSTALL) -d $(DESTDIR)$(DRACUTDIR)/dracut.conf.d
+	$(INSTALL) -m 644 ./nvmf-autoconnect/*.conf $(DESTDIR)$(DRACUTDIR)/dracut.conf.d
+
 install-zsh-completion:
 	$(INSTALL) -d $(DESTDIR)$(PREFIX)/share/zsh/site-functions
 	$(INSTALL) -m 644 -T ./completions/_nvme $(DESTDIR)$(PREFIX)/share/zsh/site-functions/_nvme
@@ -107,7 +119,7 @@ install-etc:
 		$(INSTALL) -m 644 -T ./etc/discovery.conf.in $(DESTDIR)$(SYSCONFDIR)/nvme/discovery.conf; \
 	fi
 
-install-spec: install-bin install-man install-bash-completion install-zsh-completion install-etc
+install-spec: install-bin install-man install-bash-completion install-zsh-completion install-etc install-udev
 install: install-spec install-hostparams
 
 nvme.spec: nvme.spec.in NVME-VERSION-FILE
@@ -175,7 +187,7 @@ deb-light: $(NVME) pkg nvme.control.in
 	dpkg-deb --build nvme-$(NVME_VERSION)
 
 rpm: dist
-	$(RPMBUILD) -ta nvme-$(NVME_VERSION).tar.gz
+	$(RPMBUILD) --define '_libdir ${LIBDIR}' -ta nvme-$(NVME_VERSION).tar.gz
 
 .PHONY: default doc all clean clobber install-man install-bin install
 .PHONY: dist pkg dist-orig deb deb-light rpm FORCE test
diff --git a/nvme.spec.in b/nvme.spec.in
index 6934f8f..1286e58 100644
--- a/nvme.spec.in
+++ b/nvme.spec.in
@@ -35,6 +35,11 @@ make install-spec DESTDIR=%{buildroot} PREFIX=/usr
 %{_sysconfdir}/nvme/hostnqn
 %{_sysconfdir}/nvme/hostid
 %{_sysconfdir}/nvme/discovery.conf
+%{_libdir}/udev/rules.d/70-nvmf-autoconnect.rules
+%{_libdir}/dracut/dracut.conf.d/70-nvmf-autoconnect.conf
+%{_libdir}/systemd/system/nvmf-connect at .service
+%{_libdir}/systemd/system/nvmefc-boot-connections.service
+%{_libdir}/systemd/system/nvmf-connect.target
 
 %clean
 rm -rf $RPM_BUILD_ROOT
@@ -47,6 +52,10 @@ if [ $1 -eq 1 ]; then # 1 : This package is being installed for the first time
         if [ ! -s %{_sysconfdir}/nvme/hostid ]; then
                 uuidgen > %{_sysconfdir}/nvme/hostid
         fi
+
+	# apply udev and systemd changes that we did
+	udevadm control --reload-rules && udevadm trigger
+	systemctl daemon-reload
 fi
 
 %changelog
diff --git a/nvmf-autoconnect/70-nvmf-autoconnect.conf b/nvmf-autoconnect/70-nvmf-autoconnect.conf
new file mode 100644
index 0000000..844f3d9
--- /dev/null
+++ b/nvmf-autoconnect/70-nvmf-autoconnect.conf
@@ -0,0 +1 @@
+install_items+="/usr/lib/udev/rules.d/70-nvmf-autoconnect.rules"
diff --git a/nvmf-autoconnect/70-nvmf-autoconnect.rules b/nvmf-autoconnect/70-nvmf-autoconnect.rules
new file mode 100644
index 0000000..b241b12
--- /dev/null
+++ b/nvmf-autoconnect/70-nvmf-autoconnect.rules
@@ -0,0 +1,18 @@
+#
+# nvmf-autoconnect.rules:
+#   Handles udev events which invoke automatically scan via discovery
+#   controller and connect to elements in the discovery log.
+#
+#
+
+# Events from persistent discovery controllers or nvme-fc transport events
+ACTION=="change", SUBSYSTEM=="nvme", ENV{NVME_EVENT}=="discovery",\
+  ENV{NVME_CTLR_NAME}=="*", ENV{NVME_TRTYPE}=="*", ENV{NVME_TRADDR}=="*", \
+  ENV{NVME_TRSVCID}=="*", ENV{NVME_HOST_TRADDR}=="*", \
+  RUN+="/usr/bin/systemctl --no-block start nvmf-connect at --quiet\t--device=$env{NVME_CTLR_NAME}\t--transport=$env{NVME_TRTYPE}\t--traddr=$env{NVME_TRADDR}\t--trsvcid=$env{NVME_TRSVCID}\t--host-traddr=$env{NVME_HOST_TRADDR}.service"
+
+# nvme-fc transport generated events (old-style for compatibility)
+ACTION=="change", SUBSYSTEM=="fc", ENV{FC_EVENT}=="nvmediscovery", \
+  ENV{NVMEFC_HOST_TRADDR}=="*",  ENV{NVMEFC_TRADDR}=="*", \
+  RUN+="/usr/bin/systemctl --no-block start nvmf-connect at --quiet\t--device=none\t--transport=fc\t--traddr=$env{NVMEFC_TRADDR}\t--trsvcid=none\t--host-traddr=$env{NVMEFC_HOST_TRADDR}.service"
+
diff --git a/nvmf-autoconnect/nvmefc-boot-connections.service b/nvmf-autoconnect/nvmefc-boot-connections.service
new file mode 100644
index 0000000..84f6486
--- /dev/null
+++ b/nvmf-autoconnect/nvmefc-boot-connections.service
@@ -0,0 +1,9 @@
+[Unit]
+Description=Auto-connect to subsystems on FC-NVME devices found during boot
+
+[Service]
+Type=oneshot
+ExecStart=/bin/sh -c "echo add > /sys/class/fc/fc_udev_device/nvme_discovery"
+
+[Install]
+WantedBy=default.target
diff --git a/nvmf-autoconnect/nvmf-connect.target b/nvmf-autoconnect/nvmf-connect.target
new file mode 100644
index 0000000..f64a37c
--- /dev/null
+++ b/nvmf-autoconnect/nvmf-connect.target
@@ -0,0 +1,2 @@
+[Unit]
+Description=All instances of nvmf-autoconnect daemon
diff --git a/nvmf-autoconnect/nvmf-connect at .service b/nvmf-autoconnect/nvmf-connect at .service
new file mode 100644
index 0000000..7d9f856
--- /dev/null
+++ b/nvmf-autoconnect/nvmf-connect at .service
@@ -0,0 +1,14 @@
+#
+# Unit file used by 70-nvmf-autoconnect.rules.
+#
+
+[Unit]
+Description=NVMf auto-connect scan upon nvme discovery controller Events
+After=syslog.target
+PartOf=nvmf-connect.target
+Requires=nvmf-connect.target
+
+[Service]
+Type=simple
+Environment="CONNECT_ARGS=%i"
+ExecStart=/bin/sh -c "/usr/sbin/nvme connect-all `/usr/bin/echo -e $CONNECT_ARGS`"
-- 
2.13.7