loopback.py needs locking to work reliably about fusepy HOT 2 CLOSED

I can't reproduce this bug neither on Ubuntu 9.04 nor Mac OS X, but I guess it 
is possible to happen so I added a 
lock as you suggested. Thanks!

I know this is old and marked as fixed but I wanted to add clarification to 
this since future people will hit this in their own filesystems.

What happens is fuse is running multithreaded by default.  So for reads you can 
have a race condition where multiple reads get called simultaneously resulting 
in the data coming back from the read out of order, resulting in the cmp 
failure.

If you don't want to use locks, you can specify nothreads=True in the FUSE(...) 
call

 fuse = FUSE(Loopback(argv[1]), argv[2], foreground=False, nothreads=True)