On Fri, Apr 1, 2016, at 05:13, Eric Dumazet wrote:

On Fri, 2016-04-01 at 04:01 +0200, Hannes Frederic Sowa wrote:

quoted

I thought so first, as well. But given the double check for the 
spin_lock and the "mutex" we end up with the same result for the 
lockdep_sock_is_held check.

Do you see other consequences?

Well, we release the spinlock in __release_sock()

So another thread could come and acquire the socket, then call
mutex_acquire() while the first thread did not call yet mutex_release()

So maybe lockdep will complain (but I do not know lockdep enough to
tell)

So maybe the following would be better :

(Absolutely untested, really I need to take a break)

I quickly tested the patch and my scripts didn't show any splats so far.
This patch seems more consistent albeit I don't think it is relevant for
lockdep_sock_is_held as we only flip owned while holding slock. But this
definitely needs more review.

Thanks a lot!