Re: [PATCH] utils/mount/nfs.man: add noalignwrite

[Jeff Layton <jlayton@kernel.org>]

On Mon, 2025-03-10 at 14:04 +0200, Dan Aloni wrote:
> Signed-off-by: Dan Aloni <dan.aloni@vastdata.com>
> ---
>  utils/mount/nfs.man | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
> index eab4692a87de..744411688641 100644
> --- a/utils/mount/nfs.man
> +++ b/utils/mount/nfs.man
> @@ -618,6 +618,17 @@ option is not specified,
>  the default behavior depends on the kernel version,
>  but is usually equivalent to
>  .BR "xprtsec=none" .
> +.TP 1.5i
> +.BI noalignwrite
> +This option disables the default behavior of extending write operations to full
> +page boundaries.
> +.IP
> +Normally, the NFS client rounds non-aligned writes up to the system page size,

Isn't that only true for buffered writes? That should probably be made
clear if so.

> +which can lead to "lost writes" when multiple clients write concurrently
> +to distinct non-overlapping regions. Use this option when your
> +applications perform non-aligned writes and you can guarantee that file
> +regions do not overlap, thus avoiding the need for file locking.
> +.IP
>  .SS "Options for NFS versions 2 and 3 only"
>  Use these options, along with the options in the above subsection,
>  for NFS versions 2 and 3 only.

-- 
Jeff Layton <jlayton@kernel.org>