On Fri, Jun 01, 2018 at 09:27:43AM +0100, David Howells wrote:
> Al Viro <v...@zeniv.linux.org.uk> wrote:
>
> > > 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.
>
> I kind of agree with Christoph on this point. Yes, you can use the resultant
> fd for other things, but that doesn't mean it has to be obtained initially
> through open() or openat() rather than, say, a new pick_mount() syscall.
>
> Further, having more parameters available gives us the opportunity to change
> the settings on any mounts we create at the point of creation.
open_subtree(int dirfd, const char *pathname, int flags), then? How would
flags be interpreted? What I see mapping at that thing is
* equivalent of O_PATH open
* clone subtree, O_PATH open root
* clone one mount, O_PATH open root
and apparently you want to add (orthogonal to that)
* make shared/slave/private/unbindable
* ditto with recursion?
* same for nodev/nosuid/noexec/noatime/nodiratime/relatime/ro/?
as well as usual AT_... flags (empty path, follow)
Choose the encoding...
