Re: [PATCH 1/2] kernfs: add kernfs_ops.free operation to free resources tied to the file

[Suren Baghdasaryan]

On Mon, Jun 26, 2023 at 1:31 PM Tejun Heo <tj@xxxxxxxxxx> wrote:
>
> On Mon, Jun 26, 2023 at 01:17:12PM -0700, Suren Baghdasaryan wrote:
> > diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
> > index 73f5c120def8..a7e404ff31bb 100644
> > --- a/include/linux/kernfs.h
> > +++ b/include/linux/kernfs.h
> > @@ -273,6 +273,11 @@ struct kernfs_ops {
> >        */
> >       int (*open)(struct kernfs_open_file *of);
> >       void (*release)(struct kernfs_open_file *of);
> > +     /*
> > +      * Free resources tied to the lifecycle of the file, like a
> > +      * waitqueue used for polling.
> > +      */
> > +     void (*free)(struct kernfs_open_file *of);
>
> I think this can use a bit more commenting - ie. explain that release may be
> called earlier than the actual freeing of the file and how that can lead to
> problems. Othre than that, looks fine to me.

Sure, once I get more feedback I'll post the next version with
expanded description.
Thanks!

>
> Greg, as Suren suggested, I can route both patches through the cgroup tree
> if you're okay with it.
>
> Thanks.
>
> --
> tejun