Whoops, I overlooked that this is client side, so it needs to go through
Trond or Anna, not me.
Also note:
On Fri, May 21, 2021 at 03:09:38PM -0400, Dai Ngo wrote:
> This patch, relying on the delayed unmount feature, removes this
> restriction since the mount and unmount overhead is now not applicable
> for every inter-server copy.
There's no guarantee that the same kernel version is running on client
and server, or even that the server is a Linux server.
If there's reason to expect that the lower overhead should be more
typical of servers in general, then say that....
--b.
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfs/nfs4file.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
> index 441a2fa073c8..b5821ed46994 100644
> --- a/fs/nfs/nfs4file.c
> +++ b/fs/nfs/nfs4file.c
> @@ -158,13 +158,11 @@ static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
> sync = true;
> retry:
> if (!nfs42_files_from_same_server(file_in, file_out)) {
> - /* for inter copy, if copy size if smaller than 12 RPC
> - * payloads, fallback to traditional copy. There are
> - * 14 RPCs during an NFSv4.x mount between source/dest
> - * servers.
> + /*
> + * for inter copy, if copy size is too small
> + * then fallback to generic copy.
> */
> - if (sync ||
> - count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
> + if (sync)
> return -EOPNOTSUPP;
> cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
> GFP_NOFS);
> --
> 2.9.5
