Re: [PATCH v8 01/10] kernfs: Remove reference counting for kernfs_open_node.

From: Al Viro
Date: Tue Apr 26 2022 - 16:13:40 EST


On Tue, Apr 26, 2022 at 08:29:21AM -1000, Tejun Heo wrote:

> The code is just wrong. You can end up:
>
> on = kn->attr.open;
> if (!on)
> return;
>
> // we get preempted here and someone else puts @on and then
> // recreates it

Can't happen - the caller has guaranteed that no new openers will be
coming. Look at the call chain of kernfs_drain_open_files()...


Al, back to life and staring at the pile of mail to sift through...