Description of problem:
The write call checks for a mandatory lock only once at its start. It is therefore possible for a mandatory lock request to be granted after this check but before the data is modified. An application may then see file data changed even while a mandatory lock was held.
Similarly, an exclusive mandatory lock may be granted on a file for which a read is on going, but before the read has actually completed, and the reading application may see the file data in a state which should not have been visible to it.
Version-Release number of selected component (if applicable):
Steps to Reproduce: