compat-usrmerge/convertfs

#!/bin/bash
# based on code from dracut convertfs.sh

ROOT=

# the package is installed with AutoReq off, so no guarantee that
# coreutils actually works
if ! (cp --help && mountpoint --help && mountpoint --help) > /dev/null; then
	echo "tools not functional, exit"
	exit 1
fi

# clean up after ourselves no matter how we die.
cleanup() {
    echo "Something failed, cleaning up"
    for dir in bin sbin lib lib64; do
	rm -rf -- "$ROOT/usr/${dir}.usrmerge"
    done
}

trap 'ret=$?; [[ $ret -ne 0 ]] && cleanup;exit $ret;' EXIT
trap 'exit 1;' SIGINT

mountpoint -q "$ROOT/usr" || CP_HARDLINK="-l"

set -e

# merge / and /usr in new dir in /usr
for dir in bin sbin lib lib64; do
    rm -rf -- "$ROOT/usr/${dir}.usrmerge"
    [[ -L "$ROOT/$dir" ]] && continue
    [[ -d "$ROOT/$dir" ]] || continue
    echo "Make a copy of \`$ROOT/$dir'."
    [[ -d "$ROOT/$dir" ]] \
        && cp -ax -l "$ROOT/$dir" "$ROOT/usr/${dir}.usrmerge"
    echo "Merge the copy with \`$ROOT/usr/$dir'."
    [[ -d "$ROOT/usr/${dir}.usrmerge" ]] \
        || mkdir -p "$ROOT/usr/${dir}.usrmerge"
    cp -axT $CP_HARDLINK --backup --suffix=.usrmerge~ "$ROOT/usr/$dir" "$ROOT/usr/${dir}.usrmerge"
    echo "Clean up duplicates in \`$ROOT/usr/$dir'."
    # delete all symlinks that have been backed up. /usr versions
    # override / ones
    find "$ROOT/usr/${dir}.usrmerge" -type l -name '*.usrmerge~' -delete || :
    # in rare cases the symlinks may point from /usr to /, so remove
    # the link in that case
    while read file; do
	o=${file%%.usrmerge~}
	[ -L "$o" ] && mv -f "$file" "$o"
    done < <(find "$ROOT/usr/${dir}.usrmerge" \
        -name '*.usrmerge~' -type f)
done
# switch over merged dirs in /usr
for dir in bin sbin lib lib64; do
    if [ -d "$ROOT/usr/${dir}.usrmerge" ]; then
	echo "Switch to new \`$ROOT/usr/$dir'."
	/usr/libexec/xmv "$ROOT/usr/${dir}.usrmerge" "$ROOT/usr/$dir"
    fi
done

# replace dirs in / with links to /usr
for dir in bin sbin lib lib64; do
    if [ ! -L "$ROOT/$dir" -a -d "$ROOT/$dir" ]; then
	  echo "Create \`$ROOT/$dir' symlink."
	  rm -rf "$ROOT/${dir}.usrmerge" || :
	  ln -s usr/$dir "$ROOT/${dir}.usrmerge"
	  /usr/libexec/xmv "$ROOT/$dir" "$ROOT/${dir}.usrmerge"
    fi
done

echo "Clean up backup files."
# everything seems to work; cleanup
for dir in bin sbin lib lib64; do
    for pfx in usr/ /; do
	 # if we get killed in the middle of "rm -rf", ensure not to leave
	 # an incomplete directory, which is moved back by cleanup()
	d="$ROOT/${pfx}${dir}.usrmerge"
	if [ -d "$d" ]; then
	    echo "$d ..."
	    mv "$d" "$d~"
	    rm -rf "$d~"
	fi
    done
done

# XXX: confirm this is needed
for dir in lib lib64; do
    [[ -d "$ROOT/$dir" ]] || continue
    for lib in "$ROOT"/usr/${dir}/lib*.so*.usrmerge~; do
        [[ -f $lib ]] || continue
        mv -v $lib ${lib/.so/_so}
    done
done

set +e

echo "Run ldconfig."
ldconfig -r "$ROOT"

#. $ROOT/etc/selinux/config
#if [ -n "$(command -v setfiles)" ] && [ "$SELINUX" != "disabled" ] && [ -f /etc/selinux/${SELINUXTYPE}/contexts/files/file_contexts ]; then
#    echo "Fixing SELinux labels"
#    setfiles -r $ROOT -p /etc/selinux/${SELINUXTYPE}/contexts/files/file_contexts $ROOT/sbin $ROOT/bin $ROOT/lib $ROOT/lib64 $ROOT/usr/lib $ROOT/usr/lib64 $ROOT/etc/ld.so.cache $ROOT/var/cache/ldconfig || :
#fi