On Mon, Nov 23, 2020 at 10:16:09PM -0500, Dai Ngo 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 the source server to return the stateid for COPY_NOTIFY
> request 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>
> ---
> fs/nfsd/nfs4state.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index d7f27ed6b794..33ee1a6961e3 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -793,6 +793,7 @@ struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
> refcount_set(&cps->cp_stateid.sc_count, 1);
> if (!nfs4_init_cp_state(nn, &cps->cp_stateid, NFS4_COPYNOTIFY_STID))
> goto out_free;
> + cps->cp_stateid.stid.si_generation = 1;
This affects the stateid returned by COPY_NOTIFY, but not the one
returned by COPY. I think we wan to add this to nfs4_init_cp_state()
and cover both.
--b.
> spin_lock(&nn->s2s_cp_lock);
> list_add(&cps->cp_list, &p_stid->sc_cp_list);
> spin_unlock(&nn->s2s_cp_lock);
> --
> 2.9.5
