Re: support splice reads on seq_file based procfs files

[Christoph Hellwig]

On Tue, Nov 03, 2020 at 10:57:10AM -0800, Linus Torvalds wrote:
> On Tue, Nov 3, 2020 at 10:48 AM Christoph Hellwig <hch@xxxxxx> wrote:
> >
> > ping?
> 
> It looked fine by me, although honestly, I'd prefer that last patch to
> be the minimum possible if we want this for 5.10.
> 
> Yeah, that might technically be just cpuinfo, but I'd be ok with the
> other read-only core proc files (ie I would *not* add it to anything
> that has a .proc_write operation like the ones in proc_net.c).
> 
> IOW, I'd start with just cpuinfo_proc_ops, proc_seq_ops,
> proc_single_ops, and stat_proc_ops.

I think Greg reported another test case hitting /proc/version

> 
> Because honestly, I'd rather restrict splice() as much as possible
> than try to say "everything should be able to do splice".

sure.