Re: [PATCH v4 4/6] kernfs: Don't re-lock kernfs_root::kernfs_rwsem in kernfs_fop_readdir().

[Tejun Heo]

Hello,

On Fri, Jan 24, 2025 at 06:46:12PM +0100, Sebastian Andrzej Siewior wrote:
...
> to avoid holding a global lock during a page fault. The lock drop is
> wrong since the support of renames and not a big burden since the lock
> is no longer global.

It's still a pretty big lock. Hopefully, at least name accesses can be
converted to rcu protected ones later?

> Don't re-acquire kernfs_root::kernfs_rwsem while copying the name to the
> userpace buffer.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

-- 
tejun