Re: [RFC PATCH v2 4/6] fuse: implementation of the FUSE_LOOKUP_HANDLE operation

[Miklos Szeredi]

On Tue, 16 Dec 2025 at 11:52, Amir Goldstein <amir73il@xxxxxxxxx> wrote:

> Keep in mind that we will need to store the file handle in the fuse_inode.
> Don't you think that it is better to negotiate the max_handle_size even
> if only as an upper limit?

I don't see the point.  The handle will be allocated after the lookup
has completed, and by that time will will know the exact size, so the
maximum is irrelevant.  What am I missing?

> Note that MAX_HANDLE_SZ is not even UAPI.
> It is the upper limit of the moment for the open_by_handle_at() syscall.
> FUSE protocol is by no means obligated to it, but sure we can use that
> as the default upper limit.

Yeah, but even that is excessive, since this will be a non-connectable
one, and need to fit two of them plus a header into a connectable fuse
file handle.

Thanks,
Miklos