Accepting request 421294 from home:fbui:branches:Base:System

- Add a script to fix /var/lib/machines to make it suitable for
  rollbacks (bsc#992573992573)

- Add a script to fix /var/lib/machines to make it suitable for
  rollbacks (bsc#992573992573)

OBS-URL: https://build.opensuse.org/request/show/421294
OBS-URL: https://build.opensuse.org/package/show/Base:System/systemd?expand=0&rev=946

fix-machines-subvol-for-rollbacks.sh

@@ -0,0 +1,110 @@
+#! /bin/bash
+#
+# This is used to initially create /var/lib/machines subvolume in case
+# the system we're running on is using BTRFS with the specific layout
+# used by snapper to perform snapshots, rollbacks, etc...
+#
+# Unfortunately some distros (TW) already shipped versions with
+# systemd creating a plain subvolume which breaks snapper.
+#
+# If /var/lib/machines is already populated then it's going to be
+# pretty ugly to convert the old subvolume into a new one specially
+# since it can be in use.
+#
+# Hopefully not a lot of users are using machinectl to import
+# container/VM images. So in most of the cases this directory should
+# be empty and we can then simple delete the subvolume and create a
+# new one respecting the snapper layout.
+#
+# In the rare case where /var/lib/machines is populated, we will warn
+# the user and let him fix it manually.
+#
+# In order to avoid ugly dependencies added in systemd package, this
+# script should only be called during package updates when
+# mksubvolume(8) is available. During installation, /var/lib/machines
+# is supposed to be created by the installer now.
+#
+# See bsc#992573
+#
+
+warn() {
+	echo >&2 "warning: $@"
+}
+
+is_btrfs_subvolume() {
+	# On btrfs subvolumes always have the inode 256
+	test $(stat --format=%i "$1") -eq 256
+}
+
+# This assumes the directory/subvol is emptied by the caller.
+rm_subvolume_or_directory() {
+	is_btrfs_subvolume "$1" && {
+		btrfs subvolume delete "$1"
+		return
+	}
+	rmdir "$1"
+}
+
+on_exit() {
+	# Simply print a common error message in case something went
+	# wrong.
+	if test $? -ne 0; then
+		warn "Please fix /var/lib/machines manually."
+		# FIXME: point to a documentation explaining how to do
+		# that.
+		exit 1
+	fi
+}
+
+#
+# If something is already mounted don't try to fix anything, the
+# subvolume has already been created by either mksubvolume(8) or by
+# the admin. In the later case we don't want to screw up his setup.
+#
+if mountpoint -q /var/lib/machines; then
+	exit
+fi
+
+#
+# Let's try to figure out if the current filesystem uses a Snapper
+# BTRFS specific layout. Note that TW uses a different layout than
+# SLE...
+#
+# FIXME: not sure if it's correct, reliable or optimal.
+#
+case $(findmnt -nr -t btrfs -o FSROOT / 2>/dev/null) in
+*.snapshots/*/snapshot*)
+	;;
+*)
+	exit 0
+esac
+
+trap on_exit EXIT
+
+if test -d /var/lib/machines; then
+	#
+	# Ok, we're on a system supporting rollbacks and
+	# /var/lib/machines is not a subvolume remotely mounted so it
+	# cannot be suitable for systems supporting rollback. Fix it.
+	#
+	echo "Making /var/lib/machines suitable for rollbacks..."
+
+	type mksubvolume >/dev/null 2>&1 || {
+		warn "mksubvolume(8) is not installed, aborting."
+		exit 1
+	}
+	test "$(ls -A /var/lib/machines/)" && {
+		warn "/var/lib/machines is not empty, aborting."
+		exit 1
+	}
+
+	echo "Deleting empty /var/lib/machines directory/subvolume"
+	rm_subvolume_or_directory /var/lib/machines || {
+		warn "fail to delete /var/lib/machines"
+		exit 1
+	}
+fi
+
+# At this point /var/lib/machines shouldn't exist.
+echo "Creating /var/lib/machines subvolume suitable for rollbacks."
+mksubvolume /var/lib/machines

systemd-mini.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Aug 23 10:12:13 UTC 2016 - fbui@suse.com
+
+- Add a script to fix /var/lib/machines to make it suitable for
+  rollbacks (bsc#992573992573)
+
 -------------------------------------------------------------------
 Wed Aug 10 11:30:50 UTC 2016 - meissner@suse.com
 

systemd-mini.spec

@@ -148,6 +148,7 @@ Source9:        nss-myhostname-config
 Source10:       macros.systemd.upstream
 Source11:       after-local.service
 Source12:       systemd-sysv-install
+Source13:       fix-machines-subvol-for-rollbacks.sh
 
 Source1065:     systemd-remount-tmpfs
 
@@ -840,8 +841,12 @@ ln -s ../after-local.service %{buildroot}/%{_prefix}/lib/systemd/system/multi-us
 mkdir -p %{buildroot}%{_localstatedir}/lib/systemd/backlight
 > %{buildroot}%{_localstatedir}/lib/systemd/random-seed
 
-# machined
+# On systems supporting rollbacks with btrfs, /var/lib/machines
-mkdir -p %{buildroot}%{_localstatedir}/lib/machines
+# subvolume must be created differently. Normally the installer takes
+# care of this now but some systems uses a plain subvolume that breaks
+# snapshots, rollback ("nearly everything" see bsc#992573). This
+# script should help fixing it.
+install -m 755 %{S:13} %{buildroot}/%{_prefix}/lib/systemd/
 
 %fdupes -s %{buildroot}%{_mandir}
 
@@ -987,6 +992,13 @@ enabled)  ;;
 *)        rm -f %{_prefix}/lib/systemd/system/tmp.mount
 esac
 
+# Convert /var/lib/machines subvolume to make it suitable for
+# rollbacks, if needed. See bsc#992573. The installer has been fixed
+# to create it at installation time.
+if [ $1 -gt 1 ]; then
+	%{_prefix}/lib/systemd/fix-machines-subvol-for-rollbacks.sh
+fi
+
 %postun
 /sbin/ldconfig
 if [ $1 -ge 1 ]; then
@@ -1229,6 +1241,7 @@ exit 0
 %endif
 %{_prefix}/lib/systemd/systemd-*
 %{_prefix}/lib/systemd/systemd
+%{_prefix}/lib/systemd/fix-machines-subvol-for-rollbacks.sh
 %dir %{_prefix}/lib/systemd/catalog
 %{_prefix}/lib/systemd/catalog/systemd.catalog
 %{_prefix}/lib/systemd/catalog/systemd.*.catalog
@@ -1410,7 +1423,6 @@ exit 0
 %{_datadir}/zsh/site-functions/*
 %ghost %{_localstatedir}/lib/systemd/backlight
 %ghost %{_localstatedir}/lib/systemd/random-seed
-%dir %{_localstatedir}/lib/machines
 %if %{with resolved}
 %{_sysconfdir}/dbus-1/system.d/org.freedesktop.resolve1.conf
 %{_sysconfdir}/systemd/resolved.conf

systemd.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Aug 23 10:12:13 UTC 2016 - fbui@suse.com
+
+- Add a script to fix /var/lib/machines to make it suitable for
+  rollbacks (bsc#992573992573)
+
 -------------------------------------------------------------------
 Wed Aug 10 11:30:50 UTC 2016 - meissner@suse.com
 

systemd.spec

@@ -143,6 +143,7 @@ Source9:        nss-myhostname-config
 Source10:       macros.systemd.upstream
 Source11:       after-local.service
 Source12:       systemd-sysv-install
+Source13:       fix-machines-subvol-for-rollbacks.sh
 
 Source1065:     systemd-remount-tmpfs
 
@@ -835,8 +836,12 @@ ln -s ../after-local.service %{buildroot}/%{_prefix}/lib/systemd/system/multi-us
 mkdir -p %{buildroot}%{_localstatedir}/lib/systemd/backlight
 > %{buildroot}%{_localstatedir}/lib/systemd/random-seed
 
-# machined
+# On systems supporting rollbacks with btrfs, /var/lib/machines
-mkdir -p %{buildroot}%{_localstatedir}/lib/machines
+# subvolume must be created differently. Normally the installer takes
+# care of this now but some systems uses a plain subvolume that breaks
+# snapshots, rollback ("nearly everything" see bsc#992573). This
+# script should help fixing it.
+install -m 755 %{S:13} %{buildroot}/%{_prefix}/lib/systemd/
 
 %fdupes -s %{buildroot}%{_mandir}
 
@@ -982,6 +987,13 @@ enabled)  ;;
 *)        rm -f %{_prefix}/lib/systemd/system/tmp.mount
 esac
 
+# Convert /var/lib/machines subvolume to make it suitable for
+# rollbacks, if needed. See bsc#992573. The installer has been fixed
+# to create it at installation time.
+if [ $1 -gt 1 ]; then
+	%{_prefix}/lib/systemd/fix-machines-subvol-for-rollbacks.sh || :
+fi
+
 %postun
 /sbin/ldconfig
 if [ $1 -ge 1 ]; then
@@ -1224,6 +1236,7 @@ exit 0
 %endif
 %{_prefix}/lib/systemd/systemd-*
 %{_prefix}/lib/systemd/systemd
+%{_prefix}/lib/systemd/fix-machines-subvol-for-rollbacks.sh
 %dir %{_prefix}/lib/systemd/catalog
 %{_prefix}/lib/systemd/catalog/systemd.catalog
 %{_prefix}/lib/systemd/catalog/systemd.*.catalog
@@ -1405,7 +1418,6 @@ exit 0
 %{_datadir}/zsh/site-functions/*
 %ghost %{_localstatedir}/lib/systemd/backlight
 %ghost %{_localstatedir}/lib/systemd/random-seed
-%dir %{_localstatedir}/lib/machines
 %if %{with resolved}
 %{_sysconfdir}/dbus-1/system.d/org.freedesktop.resolve1.conf
 %{_sysconfdir}/systemd/resolved.conf