On Wed, Mar 30, 2022 at 05:26:35PM +0200, Christoph Hellwig wrote: > On Wed, Mar 30, 2022 at 12:23:50PM +0200, Christian Brauner wrote: > > Make the two locations where exportfs helpers check permission to lookup > > a given inode idmapped mount aware by switching it to the lookup_one() > > helper. This is a bugfix for the open_by_handle_at() system call which > > doesn't take idmapped mounts into account currently. It's not tied to a > > specific commit so we'll just Cc stable. > > > > In addition this is required to support idmapped base layers in overlay. > > The overlay filesystem uses exportfs to encode and decode file handles > > for its index=on mount option and when nfs_export=on. > > This probably wants a Fixes tag, as without it NFS exporting idmapped > file will give slightly unexpected results. I made it so that the nfs kernel server will refuse to be mounted on top of idmapped mounts in check_export() similar to what I did originally do for overlayfs. It's unclear what the Fixes: tag would be so I'll just Cc stable. > > Otherwise looks fine: > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> Thanks!