Re: [PATCH] vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements

[Christian Brauner]

On Thu, Apr 11, 2024 at 11:13:53AM -0700, Linus Torvalds wrote:
> On Thu, 11 Apr 2024 at 10:35, Charles Mirabile <cmirabil@xxxxxxxxxx> wrote:
> >
> > And a slightly dubious addition to bypass these checks for tmpfiles
> > across the board.
> 
> Does this make sense?
> 
> I 100% agree that one of the primary reasons why people want flink()
> is that "open tmpfile, finalize contents and permissions, then link
> the final result into the filesystem".
> 
> But I would expect that the "same credentials as open" check is the
> one that really matters.

Yes. There's no need to give O_TMPFILE special status there. We also end
up with a collection of special-cases which is just unpleasant.