Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for superblock creation [ver #9]

[Linus Torvalds]

On Tue, Jul 10, 2018 at 6:15 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> Umm...  How about "use credentials of opener for everything"?

yeah, we have that for writes in general.

Nobody ever actually follows that rule. They may *think* they do, and
then they call to some helper that does "capability(CAP_SYS_WHATEVAH)"
without even realizing it.

But I'm certainly ok with writes, if it's just filling a buffer.
Preferably a standard buffer we already have, like a seqfile or pipe
(hey, splice!) or whatever.

And then you have that final op to actually "commit" the state. Which
shouldn't be a write (and not the close).

           Linus