Re: [PATCH v8 07/11] proc: flush task dcache entries from all procfs instances

From: Linus Torvalds
Date: Wed Feb 12 2020 - 15:35:27 EST


On Wed, Feb 12, 2020 at 12:03 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> What's to prevent racing with fs shutdown while you are doing the second part?

I was thinking that only the proc_flush_task() code would do this.

And that holds a ref to the vfsmount through upid->ns.

So I wasn't suggesting doing this in general - just splitting up the
implementation of d_invalidate() so that proc_flush_task_mnt() could
delay the complex part to after having traversed the RCU-protected
list.

But hey - I missed this part of the problem originally, so maybe I'm
just missing something else this time. Wouldn't be the first time.

Linus