Re: [PATCH 30/32] vfs: Allow cloning of a mount tree with open(O_PATH|O_CLONE_MOUNT) [ver #8]

[Al Viro]

On Thu, May 31, 2018 at 11:26:54PM -0700, Christoph Hellwig wrote:
> On Fri, May 25, 2018 at 01:08:38AM +0100, David Howells wrote:
> > Make it possible to clone a mount tree with a new pair of open flags that
> > are used in conjunction with O_PATH:
> > 
> >  (1) O_CLONE_MOUNT - Clone the mount or mount tree at the path.
> > 
> >  (2) O_NON_RECURSIVE - Don't clone recursively.
> 
> Err.  I don't think we should use up two O_* flags for something
> only useful for your new mount API.  Don't we have a better place
> to for these flags?
> 
> Instead of overloading this on open having a specific syscalls just
> seems like a much saner idea.

It's not just mount API; these can be used independently of that.
Think of the uses where you pass those to ...at() and you'll see
a bunch of applications of that thing.