runqemu-internal: get rid of annoying but harmless error message

The following changes since commit 2a775ebbb175dd70fc7228607c306d4ccb9e4ba4:

net-tools: Fix rerunning of do_patch task (2015-01-23 14:32:40 +0000)

are available in the git repository at:

git://git.openembedded.org/openembedded-core-contrib ChenQi/runqemu-internal-error-message
http://cgit.openembedded.org/cgit.cgi/openembedded-core-contrib/log/?h=ChenQi/runqemu-internal-error-message

Chen Qi (1):
runqemu-internal: get rid of annoying but harmless error message

 scripts/runqemu-internal | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

1.9.1

If tap0 interface has been created by other users on the system, we would
get error messages when using runqemu. Error messages are like below.
Acquiring lockfile for tap0...
touch: cannot touch ‘/tmp/qemu-tap-locks/tap0.lock’: Permission denied /buildarea2/chenqi/poky/scripts/runqemu-internal: line 139: /tmp/qemu-tap-locks/tap0.lock: Permission denied
flock: 8: Bad file descriptor

The system can still boot up because runqemu would try to create a new tap interface. So the error message above is harmless, yet somewhat annoying.

This patch fixes the above problem. With this patch, the output would be as follows.

Acquiring lockfile for tap0...
Acquiring lockfile for /tmp/qemu-tap-locks/tap0.lock failed Setting up tap interface under sudo
Acquiring lockfile for tap1...
Running qemu-system-arm...

---
 scripts/runqemu-internal | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

index 5711bd3..a0a1e96 100755
@@ -138,7 +138,11 @@ else
                 return 1
             fi
 
-            touch $lockfile.lock
+            touch $lockfile.lock 2>/dev/null
+            if [ $? -ne 0 ]; then
+                echo "Acquiring lockfile for $lockfile.lock failed"
+                return 1
+            fi
             exec 8>$lockfile.lock
             flock -n -x 8
             if [ $? -ne 0 ]; then

1.9.1