From 1777a1e58995dc40a29d4dee89c5f2ea0be13b38 Mon Sep 17 00:00:00 2001
From: Rusty Bird <rustybird@openmailbox.org>
Date: Fri, 15 Jul 2016 16:15:41 +0000
Subject: [PATCH] udev-block-add-change: don't exclude already attached devs

For example, attaching a device-mapper device to another VM increases
its "dmsetup info" open count in is_used(), which triggered its removal
from qvm-block.

(cherry picked from commit 6b32378158e7606869ff4d38fc622704373bbdf1)
---
 udev/udev-block-add-change | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/udev/udev-block-add-change b/udev/udev-block-add-change
index e0eaadd..27ccef4 100755
--- a/udev/udev-block-add-change
+++ b/udev/udev-block-add-change
@@ -11,6 +11,10 @@ MODE=w
 QDB_KEY="/qubes-block-devices/$NAME"
 
 xs_remove() {
+    if is_attached /sys$DEVPATH; then
+        return 0
+    fi
+
     if [ "$QUBES_EXPOSED" == "1" ]; then
         qubesdb-rm "$QDB_KEY/"
         qubesdb-write /qubes-block-devices ''