chreipl-fcp-mpath: toolset skeleton with initial set of udev rules

Add a new tool to s390-tools: chreipl-fcp-mpath. A toolset based on udev
to change the active re-IPL target if the current target goes into an
error-state, due to for example a pulled cable.

Add the base infrastructure consisting of a Makefile and a base set of
udev rules. Integrate the Makefile into s390-tools Make machinery.

The rules filter events base on the event subject type (dm-multipath,
scsi disk), udev action (change, or add), and device mapper action
(path failure, or path reinstated). No further processing is done right
now in case of a match; if neither of these criteria matches, the
rules exit, and the toolset won't be invoked.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

Makefile

@@ -16,7 +16,7 @@ TOOL_DIRS = zipl zdump fdasd dasdfmt dasdview tunedasd \
 	   vmconvert vmcp man mon_tools dasdinfo vmur cpuplugd ipl_tools \
 	   ziomon iucvterm hyptop cmsfs-fuse qethqoat zfcpdump zdsfs cpumf \
 	   systemd hmcdrvfs cpacfstats zdev dump2tar zkey netboot etc zpcictl \
-	   genprotimg lsstp hsci hsavmcore
+	   genprotimg lsstp hsci hsavmcore chreipl-fcp-mpath
 
 SUB_DIRS = $(BASELIB_DIRS) $(LIB_DIRS) $(TOOL_DIRS)
 

chreipl-fcp-mpath/Makefile

@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: MIT
+#
+# chreipl-fcp-mpath: use multipath information to change FCP IPL target
+# (C) Copyright IBM Corp. 2021
+#
+# Uses the following system-utilities (and shell-builtins):
+#   Utilities list in GNU Make Conventions:
+#     https://www.gnu.org/software/make/manual/make.html#Utilities-in-Makefiles
+#   Those necessary for sourced Makefiles:
+#     - ../common.mak
+#     - chreipl-fcp-mpath.mak
+#   bash:
+#     - bash
+
+override SHELL		:= /bin/bash
+override .SHELLFLAGS	:= -O globstar -O nullglob -O extglob -c
+
+# Include common s390-tools definitions
+include ../common.mak
+
+# Include common chreipl-fcp-mpath definitions
+include chreipl-fcp-mpath.mak
+
+# Local setting: .make.config
+#	You may create a file named like this in the same directory as this
+#	Makefile, and customize the build this way (e.g. re-define variables
+#	set in `chreipl-fcp-mpath.mak`, or define a `CHREIPLZFCPMP_POST_INSTALL`
+#	that is automatically called after each installation)
+ifneq ($(wildcard .make.config),)
+include $(wildcard .make.config)
+endif
+
+#
+## Build
+#
+
+.PHONY: chreipl-fcp-mpath chreipl-fcp-mpath-clean
+chreipl-fcp-mpath:
+chreipl-fcp-mpath-clean:
+all: chreipl-fcp-mpath
+clean: chreipl-fcp-mpath-clean
+
+udev/rules.d/70-chreipl-fcp-mpath.rules:
+
+chreipl-fcp-mpath: udev/rules.d/70-chreipl-fcp-mpath.rules
+
+#
+## Install
+#
+
+.PHONY: chreipl-fcp-mpath-install
+# The content of `CHREIPLZFCPMP_POST_INSTALL` (bash script) is automatically
+# called *after* installing chreipl-fcp-mpath during `make install`. If not
+# defined (the default), nothing happens. You may define this on the make
+# command line, or by creating a `.make.config` and defining the variable in
+# there.
+chreipl-fcp-mpath-install:
+	$(CHREIPLZFCPMP_POST_INSTALL)
+
+install: chreipl-fcp-mpath-install
+
+# install udev rules
+INSTDIRS += $(UDEVRULESDIR)
+
+.PHONY: chreipl-fcp-mpath-install-udev-rules
+chreipl-fcp-mpath-install-udev-rules: | $(DESTDIR)$(UDEVRULESDIR)
+chreipl-fcp-mpath-install-udev-rules: udev/rules.d/70-chreipl-fcp-mpath.rules
+	$(INSTALL_DATA) -t $(DESTDIR)$(UDEVRULESDIR)			\
+		udev/rules.d/70-chreipl-fcp-mpath.rules
+
+chreipl-fcp-mpath-install: chreipl-fcp-mpath-install-udev-rules

chreipl-fcp-mpath/chreipl-fcp-mpath.mak

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: MIT
+#
+# chreipl-fcp-mpath: use multipath information to change FCP IPL target
+# (C) Copyright IBM Corp. 2021
+#
+# Uses the following system-utilities (and shell-builtins):
+#   Utilities list in GNU Make Conventions:
+#     https://www.gnu.org/software/make/manual/make.html#Utilities-in-Makefiles
+
+#
+## Paths and Build Variables
+#
+
+# https://www.gnu.org/software/make/manual/make.html#Directory-Variables
+UDEVDIR		 = $(USRLIBDIR)/udev
+UDEVRULESDIR	 = $(UDEVDIR)/rules.d
+
+INSTALL_EXEC	 = $(INSTALL) -g $(GROUP) -o $(OWNER) --preserve-timestamps
+INSTALL_DATA	 = $(INSTALL_EXEC) --mode=0644

chreipl-fcp-mpath/udev/rules.d/70-chreipl-fcp-mpath.rules

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: MIT
+#
+# chreipl-fcp-mpath: use multipath information to change FCP IPL target
+# (C) Copyright IBM Corp. 2021
+
+# Did the event affect a multipath or scsi disk device?
+ACTION=="change", KERNEL=="dm-[0-9]*", SUBSYSTEM=="block",		\
+	ENV{DM_UUID}=="mpath-*", ENV{DM_ACTION}=="PATH_FAILED",		\
+	GOTO="chreipl_fcp_mpath_path_change"
+ACTION=="change", KERNEL=="dm-[0-9]*", SUBSYSTEM=="block",		\
+	ENV{DM_UUID}=="mpath-*", ENV{DM_ACTION}=="PATH_REINSTATED",	\
+	GOTO="chreipl_fcp_mpath_path_change"
+ACTION=="add", KERNEL=="sd[a-z]*", SUBSYSTEM=="block",			\
+	GOTO="chreipl_fcp_mpath_path_change"
+GOTO="chreipl_fcp_mpath_end"
+LABEL="chreipl_fcp_mpath_path_change"
+
+LABEL="chreipl_fcp_mpath_end"

common.mak

@@ -182,6 +182,7 @@ USRSBINDIR      = $(INSTALLDIR)/usr/sbin
 USRBINDIR       = $(INSTALLDIR)/usr/bin
 BINDIR          = $(INSTALLDIR)/sbin
 LIBDIR          = $(INSTALLDIR)/lib
+USRLIBDIR	= $(INSTALLDIR)/usr/lib
 USRLIB64DIR     = $(INSTALLDIR)/usr/lib64
 SYSCONFDIR      = $(INSTALLDIR)/etc
 MANDIR          = $(INSTALLDIR)/usr/share/man
@@ -206,10 +207,10 @@ INSTDIRS        = $(USRSBINDIR) $(USRBINDIR) $(BINDIR) $(LIBDIR) $(MANDIR) \
 			$(TOOLS_LIBDIR) $(TOOLS_DATADIR) \
 			$(ZFCPDUMP_DIR) $(SYSTEMDSYSTEMUNITDIR) \
 			$(USRLIB64DIR) $(USRINCLUDEDIR) $(ZKEYKMSPLUGINDIR) \
-			$(SOINSTALLDIR)
+			$(SOINSTALLDIR) $(USRLIBDIR)
 OWNER           = $(shell id -un)
 GROUP		= $(shell id -gn)
-export INSTALLDIR BINDIR LIBDIR USRLIB64DIR MANDIR OWNER GROUP
+export INSTALLDIR BINDIR LIBDIR USRLIBDIR USRLIB64DIR MANDIR OWNER GROUP
 
 # Special defines for zfcpdump
 ZFCPDUMP_IMAGE	= zfcpdump-image