[PATCH 3/4] nfsd: Mark back channel down if SESSION4_BACK_CHAN is clear

[Chuck Lever <chuck.lever@oracle.com>]

If a client indicates via CREATE_SESSION that no back channel
should be used on the existing connection, mark the client's
cl_cb_state DOWN instead of leaving it UNKNOWN.

Otherwise, a fresh session is created without an operational
backchannel, but the server never asserts SEQ4_STATUS_CB_PATH_DOWN.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfsd/nfs4state.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a45f244..d7cfd8b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1429,6 +1429,9 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru
 	list_add(&new->se_perclnt, &clp->cl_sessions);
 	spin_unlock(&clp->cl_lock);
 
+	if (!(cses->flags & SESSION4_BACK_CHAN))
+		clp->cl_cb_state = NFSD4_CB_DOWN;
+
 	{
 		struct sockaddr *sa = svc_addr(rqstp);
 		/*