Re: [PATCH v9 05/10] namei: O_BENEATH-style path resolution flags

[Al Viro]

On Fri, Jul 12, 2019 at 02:25:53PM +0100, Al Viro wrote:

> 	if (flags & LOOKUP_BENEATH) {
> 		nd->root = nd->path;
> 		if (!(flags & LOOKUP_RCU))
> 			path_get(&nd->root);
> 		else
> 			nd->root_seq = nd->seq;

BTW, this assignment is needed for LOOKUP_RCU case.  Without it
you are pretty much guaranteed that lazy pathwalk will fail,
when it comes to complete_walk().

Speaking of which, what would happen if LOOKUP_ROOT/LOOKUP_BENEATH
combination would someday get passed?