Bruce, Dai -
> On Sep 16, 2021, at 2:22 PM, Dai Ngo <dai.ngo@xxxxxxxxxx> wrote:
>
> When the back channel enters SEQ4_STATUS_CB_PATH_DOWN state, the client
> recovers by sending BIND_CONN_TO_SESSION but the server fails to recover
> the back channel and leaves it as NFSD4_CB_DOWN.
>
> Fix by enhancing nfsd4_bind_conn_to_session to probe the back channel
> by calling nfsd4_probe_callback.
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
I'm wondering if this one is appropriate to pull into v5.15-rc.
> ---
> fs/nfsd/nfs4state.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 54e5317f00f1..63b4d0e6fc29 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -3580,7 +3580,7 @@ static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_s
> }
>
> static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
> - struct nfsd4_session *session, u32 req)
> + struct nfsd4_session *session, u32 req, struct nfsd4_conn **conn)
> {
> struct nfs4_client *clp = session->se_client;
> struct svc_xprt *xpt = rqst->rq_xprt;
> @@ -3603,6 +3603,8 @@ static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
> else
> status = nfserr_inval;
> spin_unlock(&clp->cl_lock);
> + if (status == nfs_ok && conn)
> + *conn = c;
> return status;
> }
>
> @@ -3627,8 +3629,16 @@ __be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
> status = nfserr_wrong_cred;
> if (!nfsd4_mach_creds_match(session->se_client, rqstp))
> goto out;
> - status = nfsd4_match_existing_connection(rqstp, session, bcts->dir);
> - if (status == nfs_ok || status == nfserr_inval)
> + status = nfsd4_match_existing_connection(rqstp, session,
> + bcts->dir, &conn);
> + if (status == nfs_ok) {
> + if (bcts->dir == NFS4_CDFC4_FORE_OR_BOTH ||
> + bcts->dir == NFS4_CDFC4_BACK)
> + conn->cn_flags |= NFS4_CDFC4_BACK;
> + nfsd4_probe_callback(session->se_client);
> + goto out;
> + }
> + if (status == nfserr_inval)
> goto out;
> status = nfsd4_map_bcts_dir(&bcts->dir);
> if (status)
> --
> 2.9.5
>
--
Chuck Lever
