Re: [PATCH 3/3] ovl: Use real disk UUID for origin file handles

From: Christoph Hellwig

Date: Thu Jan 15 2026 - 01:36:37 EST


On Wed, Jan 14, 2026 at 06:54:37PM +0100, Amir Goldstein wrote:
> Perhaps this is the wrong way to abstract what overlayfs needs from real fs.
> Maybe better to extend ->encode_fh() to take a flags argument (see similar
> suggested patch at [1]) and let overlayfs do something like:

Encoding the uuid into the file handle in the kernel is the right thing
for NFS as well. Hacking in the uuids in userspace instead of the kernel
was done initially because there was no good kernel uuid infrastructure.
So doing this in general and have NFS use it when available would be
beneficial for everyone.