On Tue, Mar 03, 2020 at 03:23:51PM +0100, Christian Brauner wrote:

On Tue, Mar 03, 2020 at 02:34:42PM +0100, Miklos Szeredi wrote:

quoted

On Tue, Mar 3, 2020 at 2:14 PM Greg Kroah-Hartman
[off-list ref] wrote:

quoted

quoted

Unlimited beers for a 21-line kernel patch?  Sign me up!

Totally untested, barely compiled patch below.

Ok, that didn't even build, let me try this for real now...

Some comments on the interface:

O_LARGEFILE can be unconditional, since offsets are not exposed to the caller.

Use the openat2 style arguments; limit the accepted flags to sane ones
(e.g. don't let this syscall create a file).

If we think this is worth it, might even good to either have it support
struct open_how or have it accept two flag arguments. We sure want
openat2()s RESOLVE_* flags in there.

If you look at the patch I posted in this thread, I think it properly
supports open_how and RESOLVE_* flags.  But remember it's opening a file
that is already present, in RO mode, no creation allowed, so most of the
open_how interactions are limited.

thanks,

greg k-h