nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWN

[ Upstream commit 02579b2ff8 ]

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@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dai Ngo 2021-09-16 14:22:12 -04:00 committed by Greg Kroah-Hartman
parent f986cf2702
commit 83050cc239

View file

@ -3512,7 +3512,7 @@ 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;
@ -3535,6 +3535,8 @@ 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;
}
@ -3559,8 +3561,16 @@ __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)