linux-kernel - Re: [PATCH v2 01/31] Documentation: document EXPORT_OP

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Message-ID: <aW8yV6v8ZDiynOUm@infradead.org>
Date: Mon, 19 Jan 2026 23:44:23 -0800
From: Christoph Hellwig <hch@...radead.org>
To: Jeff Layton <jlayton@...nel.org>
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Subject: Re: [PATCH v2 01/31] Documentation: document EXPORT_OP_NOLOCKS

On Mon, Jan 19, 2026 at 11:26:18AM -0500, Jeff Layton wrote:
> +  EXPORT_OP_NOLOCKS - Disable file locking on this filesystem. Some
> +    filesystems cannot properly support file locking as implemented by
> +    nfsd. A case in point is reexport of NFS itself, which can't be done
> +    safely without coordinating the grace period handling. Other clustered
> +    and networked filesystems can be problematic here as well.

I'm not sure this is very useful.  It really needs to document what
locking semantics nfs expects, because otherwise no reader will know
if they set this or not.