Comment 9 for bug 1432387

For the last point https://github.com/harlowja/fasteners/pull/10 makes this possible,

Then cinder can just have one lock file and use something like:

    import os

    import fasteners

    class LockBucket(object):
        def __init__(self, lock_path, amount):
            self.locks = fasteners.InterProcessLock.make_offset_locks(lock_path,
                                                                      amount)
            self.lock_path = lock_path

        def __getitem__(self, item):
            m = hash(item)
            r = m % len(self.locks)
            return self.locks[r]

    lock_path = "/tmp/cinder.lock"
    locks = LockBucket(lock_path, 100)

    # then get locks from the above lock bucket