nfsd41: sequence operation

[safe/jmp/linux-2.6] / fs / nfsd / nfs4state.c

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index dfc6d94..24b6e05 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1000,6 +1000,32 @@ error:
        return status;
 }
 
+static int
+check_slot_seqid(u32 seqid, struct nfsd4_slot *slot)
+{
+       dprintk("%s enter. seqid %d slot->sl_seqid %d\n", __func__, seqid,
+               slot->sl_seqid);
+
+       /* The slot is in use, and no response has been sent. */
+       if (slot->sl_inuse) {
+               if (seqid == slot->sl_seqid)
+                       return nfserr_jukebox;
+               else
+                       return nfserr_seq_misordered;
+       }
+       /* Normal */
+       if (likely(seqid == slot->sl_seqid + 1))
+               return nfs_ok;
+       /* Replay */
+       if (seqid == slot->sl_seqid)
+               return nfserr_replay_cache;
+       /* Wraparound */
+       if (seqid == 1 && (slot->sl_seqid + 1) == 0)
+               return nfs_ok;
+       /* Misordered replay or misordered new request */
+       return nfserr_seq_misordered;
+}
+
 __be32
 nfsd4_create_session(struct svc_rqst *rqstp,
                     struct nfsd4_compound_state *cstate,
@@ -1017,11 +1043,54 @@ nfsd4_destroy_session(struct svc_rqst *r,
 }
 
 __be32
-nfsd4_sequence(struct svc_rqst *r,
+nfsd4_sequence(struct svc_rqst *rqstp,
               struct nfsd4_compound_state *cstate,
               struct nfsd4_sequence *seq)
 {
-       return -1;      /* stub */
+       struct nfsd4_session *session;
+       struct nfsd4_slot *slot;
+       int status;
+
+       spin_lock(&sessionid_lock);
+       status = nfserr_badsession;
+       session = find_in_sessionid_hashtbl(&seq->sessionid);
+       if (!session)
+               goto out;
+
+       status = nfserr_badslot;
+       if (seq->slotid >= session->se_fnumslots)
+               goto out;
+
+       slot = &session->se_slots[seq->slotid];
+       dprintk("%s: slotid %d\n", __func__, seq->slotid);
+
+       status = check_slot_seqid(seq->seqid, slot);
+       if (status == nfserr_replay_cache) {
+               cstate->slot = slot;
+               cstate->session = session;
+               goto replay_cache;
+       }
+       if (status)
+               goto out;
+
+       /* Success! bump slot seqid */
+       slot->sl_inuse = true;
+       slot->sl_seqid = seq->seqid;
+
+       cstate->slot = slot;
+       cstate->session = session;
+
+replay_cache:
+       /* Renew the clientid on success and on replay.
+        * Hold a session reference until done processing the compound:
+        * nfsd4_put_session called only if the cstate slot is set.
+        */
+       renew_client(session->se_client);
+       nfsd4_get_session(session);
+out:
+       spin_unlock(&sessionid_lock);
+       dprintk("%s: return %d\n", __func__, ntohl(status));
+       return status;
 }
 
 __be32