Re: [PATCH 01/10] VFS: support parallel updates in the one directory.

[Al Viro]

On Fri, Aug 26, 2022 at 05:13:38PM -0700, Linus Torvalds wrote:

> So I feel like if the VFS code cannot rely on locking *anyway* in the
> general case, and should work without it, then we really shouldn't
> have any locking around any of the VFS operations.

That's a really big if.  There's a bunch of places where we rely upon
->i_rwsem on directories and _not_ to provide exclusion for fs methods.
I'm still halfway through the Neil's patchset, but verifying correctness
won't be easy and I'm not optimistic about getting rid of those uses...