nfsd41: nfsd DRC logic

Replay a request in nfsd4_sequence.
Add a minorversion to struct nfsd4_compound_state.

Pass the current slot to nfs4svc_encode_compound res via struct
nfsd4_compoundres to set an NFSv4.1 DRC entry.

Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use cstate session in nfs4svc_encode_compoundres]
[nfsd41 replace nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4proc.c

@@ -936,6 +936,12 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 			BUG_ON(op->status == nfs_ok);
 
 encode_op:
+		/* Only from SEQUENCE or CREATE_SESSION */
+		if (resp->cstate.status == nfserr_replay_cache) {
+			dprintk("%s NFS4.1 replay from cache\n", __func__);
+			status = op->status;
+			goto out;
+		}
 		if (op->status == nfserr_replay_me) {
 			op->replay = &cstate->replay_owner->so_replay;
 			nfsd4_encode_replay(resp, op);
@@ -964,6 +970,7 @@ encode_op:
 		status = nfserr_jukebox;
 	}
 
+	resp->cstate.status = status;
 	fh_put(&resp->cstate.current_fh);
 	fh_put(&resp->cstate.save_fh);
 	BUG_ON(resp->cstate.replay_owner);

fs/nfsd/nfs4state.c

@@ -989,6 +989,8 @@ nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp)
 	}
 
 	resp->rqstp->rq_resused = entry->ce_resused;
+	resp->opcnt = entry->ce_opcnt;
+	resp->cstate.iovlen = entry->ce_datav.iov_len + entry->ce_rpchdrlen;
 	status = entry->ce_status;
 
 	return status;
@@ -1214,6 +1216,10 @@ nfsd4_sequence(struct svc_rqst *rqstp,
 	if (status == nfserr_replay_cache) {
 		cstate->slot = slot;
 		cstate->session = session;
+		/* Return the cached reply status and set cstate->status
+		 * for nfsd4_svc_encode_compoundres processing*/
+		status = nfsd4_replay_cache_entry(resp);
+		cstate->status = nfserr_replay_cache;
 		goto replay_cache;
 	}
 	if (status)

fs/nfsd/nfs4xdr.c

@@ -3049,6 +3049,17 @@ nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compo
 		iov = &rqstp->rq_res.head[0];
 	iov->iov_len = ((char*)resp->p) - (char*)iov->iov_base;
 	BUG_ON(iov->iov_len > PAGE_SIZE);
+	if (resp->cstate.slot != NULL) {
+		if (resp->cstate.status == nfserr_replay_cache) {
+			iov->iov_len = resp->cstate.iovlen;
+		} else {
+			nfsd4_store_cache_entry(resp);
+			dprintk("%s: SET SLOT STATE TO AVAILABLE\n", __func__);
+			resp->cstate.slot->sl_inuse = 0;
+		}
+		if (resp->cstate.session)
+			nfsd4_put_session(resp->cstate.session);
+	}
 	return 1;
 }
 

include/linux/nfsd/xdr4.h

@@ -52,6 +52,7 @@ struct nfsd4_compound_state {
 	struct nfsd4_session	*session;
 	struct nfsd4_slot	*slot;
 	__be32			*statp;
+	size_t			iovlen;
 	u32			status;
 };