[PATCH] utils: Fix lockfile_to_exclusive to avoid deadlock

We need to drop the existing lock when trying to get the exclusive lock
else we'd deadlock with another process trying to do the same thing.

Signed-off-by: Richard Purdie <[email protected]>
---
 lib/bb/utils.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/bb/utils.py b/lib/bb/utils.py
index b635f68a153..37edd435350 100644
--- a/lib/bb/utils.py
+++ b/lib/bb/utils.py
@@ -587,12 +587,13 @@ def lockfile(name, shared=False, retry=True, block=False):
         if not retry:
             return None
 
+# We have to drop the existing lock to avoid deadlocks
 def lockfile_to_exclusive(lf):
     if not lf:
         return
-    fileno = lf.fileno()
-    fcntl.flock(fileno, fcntl.LOCK_EX)
-    return
+    name = lf.name
+    unlockfile(lf)
+    return lockfile(name)
 
 def unlockfile(lf):
     """