On Wed, Dec 9, 2020 at 6:20 PM Miklos Szeredi [off-list ref] wrote:

On Wed, Dec 9, 2020 at 11:13 AM Miklos Szeredi [off-list ref] wrote:

quoted

Hard link indexing should work without fh decoding, since it is only
encoding the file handle to search for the index entry, and encoding
is not privileged.

Tested this a bit and while hard link indexing does work,  inode
lookup is broken since it uses the origin inode as a key (which is not

Yes, that is what I meant by ovl_check_origin() is broken.

available) instead of using the origin value directly.  This is
fixable, but needs a fair amount of restructuring, so let's just

Maybe it also requires on-disk changes.
We should be able to use the origin fh as the key for lower inode,
but we need the lower st_inode for initializing the ovl inode with
correct ino. If we cannot decode lower inode from origin fh, I think
we would need to store the ino in user.overlay.ino on copy up or
maintain redirect, but redirect is not supported either with user ns mount...

postpone this and disable index for now, as you suggested.

Nobody seems to be enabling it anyway :-/

Thanks,
Amir.