NFSD: Document the phases of CREATE_SESSION

As described in RFC 8881 Section 18.36.4, CREATE_SESSION can be
split into four phases. NFSD's implementation now does it like that
description.

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

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8ffa6d548a9a94bb376b0ed4a175e0168f99d2dc..994dcf8e54205d096200b77a4ee354db449ca9b9 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3762,6 +3762,8 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                goto out_free_session;
 
        spin_lock(&nn->client_lock);
+
+       /* RFC 8881 Section 18.36.4 Phase 1: Client record look-up. */
        unconf = find_unconfirmed_client(&cr_ses->clientid, true, nn);
        conf = find_confirmed_client(&cr_ses->clientid, true, nn);
        if (!conf && !unconf) {
@@ -3769,6 +3771,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                goto out_free_conn;
        }
 
+       /* RFC 8881 Section 18.36.4 Phase 2: Sequence ID processing. */
        if (conf)
                cs_slot = &conf->cl_cs_slot;
        else
@@ -3784,6 +3787,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
        cs_slot->sl_seqid++;
        cr_ses->seqid = cs_slot->sl_seqid;
 
+       /* RFC 8881 Section 18.36.4 Phase 3: Client ID confirmation. */
        if (conf) {
                status = nfserr_wrong_cred;
                if (!nfsd4_mach_creds_match(conf, rqstp))
@@ -3810,6 +3814,8 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                move_to_confirmed(unconf);
                conf = unconf;
        }
+
+       /* RFC 8881 Section 18.36.4 Phase 4: Session creation. */
        status = nfs_ok;
        /* Persistent sessions are not supported */
        cr_ses->flags &= ~SESSION4_PERSIST;