Re: [RFC PATCH v3 0/8] fuse: LOOKUP_HANDLE operation

From: Horst Birthelmer

Date: Wed Feb 25 2026 - 10:23:41 EST


On Wed, Feb 25, 2026 at 11:24:31AM +0000, Luis Henriques wrote:
> Hi,
>
> I'm sending a new version of my work on lookup_handle, even though it's
> still incomplete. As suggested elsewhere, it is now based on compound
> commands and thus it sits on top of Horst's patchset [0]. Also, because
> this version is a complete re-write of the approach presented in my previous
> RFC [1] I'm not going to detail what changed.
>
> Here's a few notes:
>
> - The code isn't yet fully testable as there are several pieces missing.
> For example, the FUSE_TMPFILE and FUSE_READDIRPLUS operations are not yet
> implemented. The NFS-related changes have also been dropped in this
> revision.
>
> - There are several details still to be sorted out in the compound
> operations. For example, the nodeid for the statx operation in the
> lookup+statx is set to FUSE_ROOT_ID.
>
> - The second operation (mkobj_handle+statx+open) is still draft (or maybe
> just wrong!). It's not handling flags correctly, and the error handling
> has to be better thought out.
>
> - Some of the patches in this set could probably be picked independently
> (e.g. patch 4 or even patch 1)
>
> So, why am I sending this broken and incomplete patchset? Well, simply
> because I'd feel more confidence getting this approach validated. I don't
> expect any through review, but I would appreciate feedback on anything that
> would help me correct major flaws.

I, personally, appreciate the fact that you sent this out, so I can understand how
you are using the compounds for this real world problem, and it gives me confidence
that I'm not completely off with the compounds.

Do you by any chance have implemented the fuse server part, too, or looked at it?
I'm just curious.

>
> [0] https://lore.kernel.org/all/20260210-fuse-compounds-upstream-v5-0-ea0585f62daa@xxxxxxx
> [1] https://lore.kernel.org/all/20251212181254.59365-1-luis@xxxxxxxxxx
>
> Cheers,
> --
> Luis

Thanks,
Horst