linux-kernel - Re: [PATCH 00/29] fs: require filesystems to explicitly opt-in to nfsd export support

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Message-ID: <9c99197dde2eafa55a1b55dce2f0d4d02c77340a.camel@kernel.org>
Date: Thu, 15 Jan 2026 13:29:41 -0500
From: Jeff Layton <jlayton@...nel.org>
To: Amir Goldstein <amir73il@...il.com>
Cc: Christian Brauner <brauner@...nel.org>, Alexander Viro	
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Subject: Re: [PATCH 00/29] fs: require filesystems to explicitly opt-in to
 nfsd export support

On Thu, 2026-01-15 at 19:17 +0100, Amir Goldstein wrote:
> On Thu, Jan 15, 2026 at 6:48 PM Jeff Layton <jlayton@...nel.org> wrote:
> > 
> > In recent years, a number of filesystems that can't present stable
> > filehandles have grown struct export_operations. They've mostly done
> > this for local use-cases (enabling open_by_handle_at() and the like).
> > Unfortunately, having export_operations is generally sufficient to make
> > a filesystem be considered exportable via nfsd, but that requires that
> > the server present stable filehandles.
> 
> Where does the term "stable file handles" come from? and what does it mean?
> Why not "persistent handles", which is described in NFS and SMB specs?
> 
> Not to mention that EXPORT_OP_PERSISTENT_HANDLES was Acked
> by both Christoph and Christian:
> 
> https://lore.kernel.org/linux-fsdevel/20260115-rundgang-leihgabe-12018e93c00c@brauner/
> 
> Am I missing anything?
> 

This was Chuck's suggested name. His point was that STABLE means that
the FH's don't change during the lifetime of the file.

I don't much care about the flag name, so if everyone likes PERSISTENT
better I'll roll with that.

Also, on the ovl patch: will fix...

Thanks for the review!
-- 
Jeff Layton <jlayton@...nel.org>