On Tue, Jul 13, 2021 at 01:32:42PM +0000, Al Viro wrote:

On Tue, Jul 13, 2021 at 01:13:21PM +0200, Christian Brauner wrote:

quoted

From: Christian Brauner <redacted>

Various filesystems use the lookup_one_len() helper to lookup a single path
component relative to a well-known starting point. Allow such filesystems to
support idmapped mounts by enabling lookup_one_len() to take the idmap into
account when calling inode_permission(). This change is a required to let btrfs
(and other filesystems) support idmapped mounts.

NAK.  Expose a new variant if you must, but leave the old one alone.

Ok, happy to do that.