On Thu 27-06-24 09:11:14, Ian Kent wrote: > On 27/6/24 04:47, Matthew Wilcox wrote: > > On Wed, Jun 26, 2024 at 04:07:49PM -0400, Lucas Karpinski wrote: > > > +++ b/fs/namespace.c > > > @@ -78,6 +78,7 @@ static struct kmem_cache *mnt_cache __ro_after_init; > > > static DECLARE_RWSEM(namespace_sem); > > > static HLIST_HEAD(unmounted); /* protected by namespace_sem */ > > > static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */ > > > +static bool lazy_unlock = false; /* protected by namespace_sem */ > > That's a pretty ugly way of doing it. How about this? > > Ha! > > That was my original thought but I also didn't much like changing all the > callers. > > I don't really like the proliferation of these small helper functions either > but if everyone > > is happy to do this I think it's a great idea. So I know you've suggested removing synchronize_rcu_expedited() call in your comment to v2. But I wonder why is it safe? I *thought* synchronize_rcu_expedited() is there to synchronize the dropping of the last mnt reference (and maybe something else) - see the comment at the beginning of mntput_no_expire() - and this change would break that? Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
