[archiso] Add archiso_shutdown hook.

STATUS: Working (std boot, loop_mnt, pxe) with copytoram=[y|n].

NEEDS: initscript > 2011.07.3, mkinitcpio > 0.7.2, mkinitcpio-busybox > 1.18.5-1

Purpose: we need this for propertly unmount $cow_device,
used for persistent dm-snapshot devices.

This hook is based on work from Tom Gundersen[#1],
but adapted for archiso things (specially the shutdown script)

[#1] http://mailman.archlinux.org/pipermail/arch-projects/2011-July/001549.html
[#2] http://projects.archlinux.org/initscripts.git/commit/?id=1fa7b4b453e96533ae1db3630031285e5fc302b3
[#3] http://mailman.archlinux.org/pipermail/arch-projects/2011-August/001749.html

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@yahoo.com.ar>

README

@@ -121,7 +121,8 @@ if nothing is specified on command line.
 * archiso_pxe_nbd
  + mkinitcpio-nfs-utils    for ipconfig
  + nbd                     for nbd-client
-
+* archiso_shutdown
+ + (none)
 
 
 *** Image types generated by mkarchiso.

archiso/Makefile

@@ -12,6 +12,9 @@ install-hooks:
 	# hooks/install are needed by mkinitcpio
 	install -D -m 644 hooks/archiso $(DESTDIR)/lib/initcpio/hooks/archiso
 	install -D -m 644 install/archiso $(DESTDIR)/lib/initcpio/install/archiso
+	install -D -m 755 archiso_shutdown $(DESTDIR)/lib/initcpio/archiso_shutdown
+	install -D -m 644 hooks/archiso_shutdown $(DESTDIR)/lib/initcpio/hooks/archiso_shutdown
+	install -D -m 644 install/archiso_shutdown $(DESTDIR)/lib/initcpio/install/archiso_shutdown
 	install -D -m 644 archiso_pxe_nbd $(DESTDIR)/lib/initcpio/archiso_pxe_nbd
 	install -D -m 644 hooks/archiso_pxe_nbd $(DESTDIR)/lib/initcpio/hooks/archiso_pxe_nbd
 	install -D -m 644 install/archiso_pxe_nbd $(DESTDIR)/lib/initcpio/install/archiso_pxe_nbd
@@ -32,6 +35,9 @@ uninstall:
 	rm -f $(DESTDIR)/usr/bin/testiso
 	rm -f $(DESTDIR)/lib/initcpio/hooks/archiso
 	rm -f $(DESTDIR)/lib/initcpio/install/archiso
+	rm -f $(DESTDIR)/lib/initcpio/archiso_shutdown
+	rm -f $(DESTDIR)/lib/initcpio/hooks/archiso_shutdown
+	rm -f $(DESTDIR)/lib/initcpio/install/archiso_shutdown
 	rm -f $(DESTDIR)/lib/initcpio/archiso_pxe_nbd
 	rm -f $(DESTDIR)/lib/initcpio/hooks/archiso_pxe_nbd
 	rm -f $(DESTDIR)/lib/initcpio/install/archiso_pxe_nbd

archiso/archiso_shutdown

@@ -0,0 +1,43 @@
+#!/bin/sh
+
+# /oldroot depends on things inside /oldroot/run/archiso...
+mkdir /oldrun
+mount --move /oldroot/run /oldrun
+
+# Unmount all mounts now.
+umount $(mount | awk '$3 ~/^\/oldroot/ {print $3}' | sort -r)
+
+# Remove all dm-snapshot devices.
+dmsetup remove_all
+
+# Remove all loopback devices made for dm-snapshots devices
+# other misc loops like used for pure squashfs images
+# and unmount/detach *.fs.sfs images.
+for _lup in $(ls -r /dev/loop[1-9][0-9][0-9]); do
+    if ! losetup -d ${_lup} 2> /dev/null; then
+        umount -d ${_lup}
+    fi
+done
+
+# Unmount the space used to store *.cow.
+umount /oldrun/archiso/cowspace
+
+# Unmount boot device if needed (no copytoram=y used)
+if [[ ! -d /oldrun/archiso/copytoram ]]; then
+    umount /oldrun/archiso/bootmnt
+    # Detach img_loop= and unmount img_dev= (archiso_loop_mnt hook)
+    if [[ -f /oldrun/archiso/img_dev_loop ]]; then
+        losetup -d $(cat /oldrun/archiso/img_dev_loop)
+        umount /oldrun/archiso/img_dev
+    fi
+    if [[ -f /oldrun/archiso/nbd_client.pid ]]; then
+        nbd-client -d /dev/nbd0
+    fi
+fi
+
+# reboot / poweroff / halt, depending on the argument passed by init
+# if something invalid is passed, we halt
+case "$1" in
+  reboot|poweroff|halt) "$1" -f ;;
+  *) halt -f;;
+esac

archiso/hooks/archiso_shutdown

@@ -0,0 +1,22 @@
+run_hook ()
+{
+    msg -n ":: Creating shutdown ramfs..."
+
+    mkdir -p /run/initramfs/usr/bin
+    mkdir /run/initramfs/usr/sbin
+    mkdir /run/initramfs/bin
+    mkdir /run/initramfs/sbin
+    mkdir /run/initramfs/lib
+    cp /bin/busybox /run/initramfs/bin/
+    cp /lib/ld-* /run/initramfs/lib/
+    cp /lib/lib* /run/initramfs/lib/
+    cp /sbin/dmsetup /run/initramfs/sbin/
+    if [[ -x /bin/nbd-client ]]; then
+        cp /bin/nbd-client /run/initramfs/bin/
+    fi
+
+    chroot /run/initramfs /bin/busybox --install
+    cp /shutdown /run/initramfs/
+
+    msg "done."
+}

archiso/install/archiso_shutdown

@@ -0,0 +1,13 @@
+build() {
+    SCRIPT="archiso_shutdown"
+    add_binary /lib/initcpio/archiso_shutdown /shutdown
+}
+
+help () {
+    cat <<HELPEOF
+This hook will create a shutdown initramfs in /run/initramfs
+that we can pivot to on shutdown in order to unmount / and
+and others mount points, dm-snapshot devices and loopback devices.
+Mostly usefull for dm-snapshot persistent.
+HELPEOF
+}

configs/releng/build.sh

@@ -43,10 +43,11 @@ make_customize_root_image() {
 make_setup_mkinitcpio() {
    if [[ ! -e ${work_dir}/build.${FUNCNAME} ]]; then
         local _hook
-        for _hook in archiso archiso_pxe_nbd archiso_loop_mnt; do
+        for _hook in archiso archiso_shutdown archiso_pxe_nbd archiso_loop_mnt; do
             cp /lib/initcpio/hooks/${_hook} ${work_dir}/root-image/lib/initcpio/hooks
             cp /lib/initcpio/install/${_hook} ${work_dir}/root-image/lib/initcpio/install
         done
+        cp /lib/initcpio/archiso_shutdown ${work_dir}/root-image/lib/initcpio
         cp /lib/initcpio/archiso_pxe_nbd ${work_dir}/root-image/lib/initcpio
         : > ${work_dir}/build.${FUNCNAME}
    fi

configs/releng/mkinitcpio.conf

@@ -1,2 +1,2 @@
-HOOKS="base udev memdisk archiso archiso_pxe_nbd archiso_loop_mnt pata scsi sata usb fw pcmcia filesystems usbinput"
+HOOKS="base udev memdisk archiso_shutdown archiso archiso_pxe_nbd archiso_loop_mnt pata scsi sata usb fw pcmcia filesystems usbinput"
 COMPRESSION="xz"