# Re: \[PATCH 13/19\] vfs: Add a mount-notification facility \[ver \#16\]

- From: David Howells \<dhowells@redhat.com\>
- Date: 2020-02-21 17:06:32 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2020/02/173557
- Thread: https://ratatoskr.run/linux-api/2020/02/173129/t.md

```text
Jann Horn [ref] wrote:

> > What's the best way to write a lockdep assertion?
> >
> >         BUG_ON(!lockdep_is_held(lock));
> 
> lockdep_assert_held(lock) is the normal way, I think - that will
> WARN() if lockdep is enabled and the lock is not held.

Okay.  But what's the best way with a seqlock_t?  It has two dep maps in it.
Do I just ignore the one attached to the spinlock?

David

```