[rds-devel] [PATCH net] rds: Incorrect reference counting in TCP socket creation

[Sowmini Varadhan]

On (03/01/18 20:19), Ka-Cheong Poon wrote:
> >>
> >>-       new_sock->type = sock->type;
> >>-       new_sock->ops = sock->ops;
> >>         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true);
> >>         if (ret < 0)
> >>                 goto out;
> >>
> >>+       new_sock->ops = sock->ops;
> >
> >How is this delta relevant to the commit comment? Seems unrelated?
> 
> 
> Note that sock_release() checks if sock->ops is set before
> decrementing the refcnt.  By moving the ops assignment after
> the ops->accept() call, we save increasing the refcnt in
> case the ops->accept() fails.  Otherwise, the __module_get()
> needs to be moved before ops->accept() to handle this failure
> case.

I see, thanks for clarification.

It may be helpful to have some comment in there, in case some other
module trips on something similar in the future.

--Sowmini