NFSD: Combine decode operations for v4 and v4.1

We were using a different array of function pointers to represent each
minor version.  This makes adding a new minor version tedious, since it
needs a step to copy, paste and modify a new version of the same
functions.

This patch combines the v4 and v4.1 arrays into a single instance and
will check minor version support inside each decoder function.
Signed-off-by: NAnna Schumaker <bjschuma@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4xdr.c

@@ -945,13 +945,16 @@ static __be32
 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
 {
 	DECODE_HEAD;
-		    
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
 	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
 	if (status)
 		return status;
 	READ_BUF(4);
 	READ32(open_conf->oc_seqid);
-						        
+
 	DECODE_TAIL;
 }
 
@@ -990,6 +993,14 @@ nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
 	DECODE_TAIL;
 }
 
+static __be32
+nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
+{
+	if (argp->minorversion == 0)
+		return nfs_ok;
+	return nfserr_notsupp;
+}
+
 static __be32
 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
 {
@@ -1061,6 +1072,9 @@ nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
 {
 	DECODE_HEAD;
 
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
 	READ_BUF(sizeof(clientid_t));
 	COPYMEM(clientid, sizeof(clientid_t));
 
@@ -1111,6 +1125,9 @@ nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclient
 {
 	DECODE_HEAD;
 
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
 	READ_BUF(NFS4_VERIFIER_SIZE);
 	COPYMEM(setclientid->se_verf.data, NFS4_VERIFIER_SIZE);
 
@@ -1137,6 +1154,9 @@ nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_s
 {
 	DECODE_HEAD;
 
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
 	READ_BUF(8 + NFS4_VERIFIER_SIZE);
 	COPYMEM(&scd_c->sc_clientid, 8);
 	COPYMEM(&scd_c->sc_confirm, NFS4_VERIFIER_SIZE);
@@ -1220,6 +1240,9 @@ nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_rel
 {
 	DECODE_HEAD;
 
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
 	READ_BUF(12);
 	COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
 	READ32(rlockowner->rl_owner.len);
@@ -1519,7 +1542,7 @@ static nfsd4_dec nfsd4_dec_ops[] = {
 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
-	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
@@ -1536,46 +1559,6 @@ static nfsd4_dec nfsd4_dec_ops[] = {
 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
-};
-
-static nfsd4_dec nfsd41_dec_ops[] = {
-	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
-	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
-	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
-	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
-	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
-	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
-	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
-	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
-	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
-	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
-	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
-	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
-	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
-	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
-	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
-	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
-	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
-	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
-	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
-	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
-	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
-	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
-	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_SETCLIENTID_CONFIRM]= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
-	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
-	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_notsupp,
 
 	/* new operations for NFSv4.1 */
 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
@@ -1599,23 +1582,23 @@ static nfsd4_dec nfsd41_dec_ops[] = {
 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
 };
 
-struct nfsd4_minorversion_ops {
-	nfsd4_dec *decoders;
-	int nops;
-};
-
-static struct nfsd4_minorversion_ops nfsd4_minorversion[] = {
-	[0] = { nfsd4_dec_ops, ARRAY_SIZE(nfsd4_dec_ops) },
-	[1] = { nfsd41_dec_ops, ARRAY_SIZE(nfsd41_dec_ops) },
-	[2] = { nfsd41_dec_ops, ARRAY_SIZE(nfsd41_dec_ops) },
-};
+static inline bool
+nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
+{
+	if (op->opnum < FIRST_NFS4_OP || op->opnum > LAST_NFS4_OP)
+		return false;
+	else if (argp->minorversion == 0 && op->opnum > OP_RELEASE_LOCKOWNER)
+		return false;
+	else if (argp->minorversion == 1 && op->opnum > OP_RECLAIM_COMPLETE)
+		return false;
+	return true;
+}
 
 static __be32
 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 {
 	DECODE_HEAD;
 	struct nfsd4_op *op;
-	struct nfsd4_minorversion_ops *ops;
 	bool cachethis = false;
 	int i;
 
@@ -1640,10 +1623,9 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 		}
 	}
 
-	if (argp->minorversion >= ARRAY_SIZE(nfsd4_minorversion))
+	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
 		argp->opcnt = 0;
 
-	ops = &nfsd4_minorversion[argp->minorversion];
 	for (i = 0; i < argp->opcnt; i++) {
 		op = &argp->ops[i];
 		op->replay = NULL;
@@ -1651,8 +1633,8 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 		READ_BUF(4);
 		READ32(op->opnum);
 
-		if (op->opnum >= FIRST_NFS4_OP && op->opnum <= LAST_NFS4_OP)
-			op->status = ops->decoders[op->opnum](argp, &op->u);
+		if (nfsd4_opnum_in_range(argp, op))
+			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
 		else {
 			op->opnum = OP_ILLEGAL;
 			op->status = nfserr_op_illegal;