Yeah, this is the real problem. To be clear though (the article skimmed over lots of details to remain generally accessible), I was not discussing the release_sock() function which releases a lock on a socket [1]. Instead, my code registers a set of function pointers in a struct [2]. While release_sock() does have documentation, the function pointer of the same name does not, and the only examples I have are other files of code within the MPTCP protocol implementation. The callback is related to the function, to be sure, and so I should have connected the dots, but this is how we learn.

While I was making a baseless assumption, I like to believe that it was baseless because there was not enough available information, and not because I was ignoring obvious sources of information :P

[1]: http://lxr.free-electrons.com/ident?v=4.1;i=release_sock [2]: https://github.com/multipath-tcp/mptcp/blob/e77e2ca0b5339af2...