runqemu: acquire_lock() should fail when failed to open the file

The following changes since commit d77fe838ab7631a19e90ff4226f0712e54aa4e22:

scripts: add tool to scan for bashisms recipe shell scripts (2016-09-16 15:19:31 +0100)

are available in the git repository at:

git://git.openembedded.org/openembedded-core-contrib rbt/rq_lock
http://cgit.openembedded.org/cgit.cgi/openembedded-core-contrib/log/?h=rbt/rq_lock

Robert Yang (1):
runqemu: acquire_lock() should fail when failed to open the file

 scripts/runqemu | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

2.9.0

The open(self.lock, 'w') may fail when the lock is created by other users, return false for this case to let it try other devices.

Fixed:
runqemu - INFO - Running /sbin/ip link...
runqemu - INFO - Acquiring lockfile /tmp/qemu-tap-locks/tap0.lock... Traceback (most recent call last):
File "/buildarea/lyang1/poky/scripts/runqemu", line 972, in <module>
ret = main()
File "/buildarea/lyang1/poky/scripts/runqemu", line 963, in main
config.setup_network()
File "/buildarea/lyang1/poky/scripts/runqemu", line 810, in setup_network
self.setup_tap()
File "/buildarea/lyang1/poky/scripts/runqemu", line 761, in setup_tap
if self.acquire_lock():
File "/buildarea/lyang1/poky/scripts/runqemu", line 182, in acquire_lock
lock_descriptor = open(self.lock, 'w')
PermissionError: [Errno 13] Permission denied: '/tmp/qemu-tap-locks/tap0.lock'

---
 scripts/runqemu | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

index b6bc0ba..3805685 100755
@@ -168,14 +168,14 @@ class BaseConfig(object):
 
     def acquire_lock(self):
         logger.info("Acquiring lockfile %s..." % self.lock)
-        lock_descriptor = open(self.lock, 'w')
         try:
-            fcntl.flock(lock_descriptor, fcntl.LOCK_EX|fcntl.LOCK_NB)
+            self.lock_descriptor = open(self.lock, 'w')
+            fcntl.flock(self.lock_descriptor, fcntl.LOCK_EX|fcntl.LOCK_NB)
         except Exception as e:
             logger.info("Acquiring lockfile %s failed: %s" % (self.lock, e))
-            lock_descriptor.close()
+            if self.lock_descriptor:
+                self.lock_descriptor.close()
             return False
-        self.lock_descriptor = lock_descriptor
         return True
 
     def release_lock(self):

2.9.0