> On Nov 30, 2020, at 4:24 PM, Dai Ngo <dai.ngo@xxxxxxxxxx> wrote:
>
> Since commit b4868b44c5628 ("NFSv4: Wait for stateid updates after
> CLOSE/OPEN_DOWNGRADE"), every inter server copy operation suffers 5
> seconds delay regardless of the size of the copy. The delay is from
> nfs_set_open_stateid_locked when the check by nfs_stateid_is_sequential
> fails because the seqid in both nfs4_state and nfs4_stateid are 0.
>
> Fix by modifying nfs4_init_cp_state to return the stateid with seqid 1
> instead of 0. This is also to conform with section 4.8 of RFC 7862.
>
> Here is the relevant paragraph from section 4.8 of RFC 7862:
>
> A copy offload stateid's seqid MUST NOT be zero. In the context of a
> copy offload operation, it is inappropriate to indicate "the most
> recent copy offload operation" using a stateid with a seqid of zero
> (see Section 8.2.2 of [RFC5661]). It is inappropriate because the
> stateid refers to internal state in the server and there may be
> several asynchronous COPY operations being performed in parallel on
> the same file by the server. Therefore, a copy offload stateid with
> a seqid of zero MUST be considered invalid.
>
> Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
Applied for the next merge window. See the cel-next topic branch in
this repo:
git://git.linux-nfs.org/projects/cel/cel-2.6.git
See also:
http://git.linux-nfs.org/?p=cel/cel-2.6.git;a=shortlog;h=refs/heads/cel-next
> ---
> fs/nfsd/nfs4state.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index d7f27ed6b794..47006eec724e 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -769,6 +769,7 @@ static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
> spin_lock(&nn->s2s_cp_lock);
> new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, stid, 0, 0, GFP_NOWAIT);
> stid->stid.si_opaque.so_id = new_id;
> + stid->stid.si_generation = 1;
> spin_unlock(&nn->s2s_cp_lock);
> idr_preload_end();
> if (new_id < 0)
> --
> 2.9.5
>
--
Chuck Lever
