[p4l4g4]

You can't just lock on the file operations, since this problem comes from thread interruptions. No interrupt, no problem. So, instead you need to make file operations and _any_ thread interrupt mutual exclusive.

Finding and patching all possible locations which could interrupt your threads doing file operations is probably a foolish effort.

So, raising the limit, or load balancing (depending on the type of application) is probably the best solution.