[RFC] 'Fixes' for initramfs creation

*** INCOMPLETE ***

This is not entirely correct, it works in some cases for me, though
not reliably, it seems I have to ./autogen.sh twice to get the files
in etc/init.d/ created and put in place for the initramfs Makefile.

zfs-functions is required, copy to /etc/zfs/

The zfs hook that copies files will error on critical files.  The
argument for this is we do not want to create a non-functional
initramfs.

Some files are optional, those we do silently ignore.

contrib/initramfs/Makefile.am

@@ -3,21 +3,28 @@ initrddir = $(datarootdir)/initramfs-tools
 initrd_SCRIPTS = \
 	conf.d/zfs conf-hooks.d/zfs hooks/zfs scripts/zfs scripts/local-top/zfs
 
-SUBDIRS = hooks scripts
+SUBDIRS = hooks scripts ../../etc
 
 EXTRA_DIST = \
+	$(top_srcdir)/etc/init.d/zfs \
+	$(top_srcdir)/etc/init.d/zfs-functions \
 	$(top_srcdir)/contrib/initramfs/conf.d/zfs \
 	$(top_srcdir)/contrib/initramfs/conf-hooks.d/zfs \
 	$(top_srcdir)/contrib/initramfs/README.initramfs.markdown
 
 install-initrdSCRIPTS: $(EXTRA_DIST)
 	for d in conf.d conf-hooks.d hooks scripts scripts/local-top; do \
-	  $(MKDIR_P) $(DESTDIR)$(initrddir)/$$d; \
-	  cp $(top_srcdir)/contrib/initramfs/$$d/zfs \
+	  $(MKDIR_P) -v $(DESTDIR)$(initrddir)/$$d; \
+	  cp -v $(top_srcdir)/contrib/initramfs/$$d/zfs \
 	    $(DESTDIR)$(initrddir)/$$d/; \
 	done
-	if [ -f etc/init.d/zfs ]; then \
-	  $(MKDIR_P) $(DESTDIR)$(DEFAULT_INITCONF_DIR); \
-	  cp $(top_srcdir)/etc/init.d/zfs \
-	    $(DESTDIR)$(DEFAULT_INITCONF_DIR)/; \
-	fi
+
+	$(MKDIR_P) -v $(DESTDIR)$(DEFAULT_INITCONF_DIR) $(DESTDIR)/etc/zfs/
+
+	cp -v $(top_srcdir)/etc/init.d/zfs \
+	  $(DESTDIR)$(DEFAULT_INITCONF_DIR)/
+
+	$(MKDIR_P) -v $(DESTDIR)/etc/init.d/
+
+	cp -v $(top_srcdir)/etc/init.d/zfs-functions \
+	  $(DESTDIR)/etc/init.d/

contrib/initramfs/hooks/zfs.in

@@ -3,19 +3,24 @@
 # Add ZoL filesystem capabilities to an initrd, usually for a native ZFS root.
 #
 
+# fail on errors; this might be annoying but for now it's more
+# important to fail during initramfs creation where we can do
+# something about it, vs after a boot when we can't
+set -eu
+
 # This hook installs udev rules for ZoL.
 PREREQ="zdev"
 
 # These prerequisites are provided by the zfsutils package. The zdb utility is
 # not strictly required, but it can be useful at the initramfs recovery prompt.
 COPY_EXEC_LIST="@sbindir@/zdb @sbindir@/zpool @sbindir@/zfs"
 COPY_EXEC_LIST="$COPY_EXEC_LIST @mounthelperdir@/mount.zfs @udevdir@/vdev_id"
-COPY_FILE_LIST="/etc/hostid @sysconfdir@/zfs/zpool.cache"
-COPY_FILE_LIST="$COPY_FILE_LIST @sysconfdir@/default/zfs"
 COPY_FILE_LIST="$COPY_FILE_LIST @sysconfdir@/zfs/zfs-functions"
-COPY_FILE_LIST="$COPY_FILE_LIST @sysconfdir@/zfs/vdev_id.conf"
 COPY_FILE_LIST="$COPY_FILE_LIST @udevruledir@/69-vdev.rules"
 
+# These are not required
+OPTIONAL_FILE_LIST="/etc/hostid @sysconfdir@/default/zfs @sysconfdir@/zfs/vdev_id.conf"
+
 # These prerequisites are provided by the base system.
 COPY_EXEC_LIST="$COPY_EXEC_LIST /usr/bin/dirname /bin/hostname /sbin/blkid"
 COPY_EXEC_LIST="$COPY_EXEC_LIST /usr/bin/env"
@@ -66,6 +71,15 @@ do
 done
 
 for ii in $COPY_FILE_LIST
+do
+	dir=$(dirname "$ii")
+	[ -d "$dir" ] && mkdir -p "$DESTDIR/$dir"
+	[ -f "$ii" ] && cp -p "$ii" "$DESTDIR/$ii"
+	# error if missing
+	[ -e "$ii" ]
+done
+
+for ii in $OPTIONAL_FILE_LIST
 do
 	dir=$(dirname "$ii")
 	[ -d "$dir" ] && mkdir -p "$DESTDIR/$dir"

rpm/generic/zfs.spec.in

@@ -480,6 +480,8 @@ systemctl --system daemon-reload >/dev/null || true
 %if 0%{?_initramfs}
 %files initramfs
 %doc contrib/initramfs/README.initramfs.markdown
+/etc/default/zfs
+/etc/init.d/zfs-functions
 /usr/share/initramfs-tools/*
 %else
 # Since we're not building the initramfs package,