On Wed, 2024-08-14 at 03:40 +0100, Al Viro wrote: > On Wed, Aug 14, 2024 at 03:18:17AM +0100, Al Viro wrote: > > > That's not the only problem; your "is it negative" test is inherently > > racy in RCU mode. IOW, what is positive at the time you get here can > > bloody well go negative immediately afterwards. Hit that with > > O_CREAT and you've got a bogus ENOENT... > > Hmm... OTOH, in that case you end up in step_into(), which will do the > right thing... > > How well does that series survive NFS client regression tests? > That's where I'd expect potentially subtle shite, what with short-circuited > ->d_revalidate() on the final pathwalk step in open()... Christian took in my v3 patch which is a bit different from this one. It seems to be doing fine in testing with NFS and otherwise. I don't think we short-circuit the d_revalidate though, do we? That version calls lookup_fast on the last component which should d_revalidate the last dentry before returning it. -- Jeff Layton <jlayton@xxxxxxxxxx>
