On Tue, Dec 11, 2018 at 11:46:53AM -0700, Jens Axboe wrote: > On 12/11/18 11:45 AM, Matthew Wilcox wrote: > > I think we need the rcu read lock here to prevent ctx from being freed > > under us by free_ioctx(). > > Then that begs the question, how about __xa_load() that is already called > under RCU read lock?
I've been considering adding it to the API, yes. I was under the impression that nested rcu_read_lock() calls were not expensive, even with CONFIG_PREEMPT.
