From f7b8a79ce61c49cd73aaf2040790c854b11459a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Wed, 13 Jun 2018 15:48:00 +0200
Subject: [PATCH] udev: create /dev/mapper/dmroot -> xvda3 symlink when its
 mounted directly

When root device is available read-write (TemplateVM/StandaloneVM), its
mounted directly, instead of using device-mapper layer. But
/dev/mapper/dmroot still needs to exists (it is pointed from
/etc/fstab), otherwise various tools, including grub-mkconfig get
confused.
Create a symlink using udev rule. It is already done in initramfs, and
in case of Fedora that udev rule/symlink survive switching to
non-initramfs udev, but not on Debian. So, add appropriate udev rules
file.

Fixes QubesOS/qubes-issues#3178
---
 rpm_spec/qubes-utils.spec.in | 2 +-
 udev/Makefile                | 1 +
 udev/udev-qubes-dmroot.rules | 5 +++++
 3 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 udev/udev-qubes-dmroot.rules

diff --git a/rpm_spec/qubes-utils.spec.in b/rpm_spec/qubes-utils.spec.in
index 324ad16..0205317 100644
--- a/rpm_spec/qubes-utils.spec.in
+++ b/rpm_spec/qubes-utils.spec.in
@@ -118,7 +118,7 @@ rm -rf $RPM_BUILD_ROOT
 
 %files
 %defattr(-,root,root,-)
-/lib/udev/rules.d/99-qubes-*.rules
+/lib/udev/rules.d/*-qubes-*.rules
 /usr/lib/qubes/udev-*
 %{_sbindir}/meminfo-writer
 %{_unitdir}/qubes-meminfo-writer.service
diff --git a/udev/Makefile b/udev/Makefile
index 6eff34a..ec3c6e3 100644
--- a/udev/Makefile
+++ b/udev/Makefile
@@ -5,6 +5,7 @@ install:
 	cp udev-qubes-block.rules $(DESTDIR)$(SYSLIBDIR)/udev/rules.d/99-qubes-block.rules
 	cp udev-qubes-usb.rules $(DESTDIR)$(SYSLIBDIR)/udev/rules.d/99-qubes-usb.rules
 	cp udev-qubes-misc.rules $(DESTDIR)$(SYSLIBDIR)/udev/rules.d/99-qubes-misc.rules
+	cp udev-qubes-dmroot.rules $(DESTDIR)$(SYSLIBDIR)/udev/rules.d/90-qubes-dmroot.rules
 
 	mkdir -p $(DESTDIR)$(SCRIPTSDIR)
 	cp udev-block-add-change $(DESTDIR)$(SCRIPTSDIR)
diff --git a/udev/udev-qubes-dmroot.rules b/udev/udev-qubes-dmroot.rules
new file mode 100644
index 0000000..304ebee
--- /dev/null
+++ b/udev/udev-qubes-dmroot.rules
@@ -0,0 +1,5 @@
+# Create /dev/mapper/dmroot symlink on TemplateVM/StandaloneVM to make
+# grub-mkconfig happy.
+# On TemplateBasedVM, it is really a device mapper device.
+
+SUBSYSTEM=="block", ENV{ID_PART_ENTRY_NAME}=="Root\x20filesystem", ATTR{ro}=="0", SYMLINK+="mapper/dmroot"