NFSv4: use the (more efficient) NFSv2/v3-like XDR scheme for hard linking

fs/nfs/nfs4proc.c

@@ -238,20 +238,6 @@ nfs4_setup_getfh(struct nfs4_compound *cp, struct nfs_fh *fhandle)
 	cp->req_nops++;
 }
 
-static void
-nfs4_setup_link(struct nfs4_compound *cp, struct qstr *name,
-		struct nfs4_change_info *info)
-{
-	struct nfs4_link *link = GET_OP(cp, link);
-
-	link->ln_namelen = name->len;
-	link->ln_name = name->name;
-	link->ln_cinfo = info;
-
-	OPNUM(cp) = OP_LINK;
-	cp->req_nops++;
-}
-
 static void
 nfs4_setup_putfh(struct nfs4_compound *cp, struct nfs_fh *fhandle)
 {
@@ -1300,33 +1286,25 @@ static int nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,
 	return nfs4_map_errors(status);
 }
 
-static int
-nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
+static int nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
 {
-	struct nfs4_compound	compound;
-	struct nfs4_op		ops[7];
-	struct nfs4_change_info	dir_cinfo;
-	struct nfs_fattr	dir_attr, fattr;
+	struct nfs4_link_arg arg = {
+		.fh     = NFS_FH(inode),
+		.dir_fh = NFS_FH(dir),
+		.name   = name,
+	};
+	struct nfs4_change_info	cinfo = { };
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LINK],
+		.rpc_argp = &arg,
+		.rpc_resp = &cinfo,
+	};
 	int			status;
 
-	dir_attr.valid = 0;
-	fattr.valid = 0;
-	
-	nfs4_setup_compound(&compound, ops, NFS_SERVER(inode), "link");
-	nfs4_setup_putfh(&compound, NFS_FH(inode));
-	nfs4_setup_savefh(&compound);
-	nfs4_setup_putfh(&compound, NFS_FH(dir));
-	nfs4_setup_link(&compound, name, &dir_cinfo);
-	nfs4_setup_getattr(&compound, &dir_attr);
-	nfs4_setup_restorefh(&compound);
-	nfs4_setup_getattr(&compound, &fattr);
-	status = nfs4_call_compound(&compound, NULL, 0);
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	if (!status)
+		update_changeattr(dir, &cinfo);
 
-	if (!status) {
-		process_cinfo(&dir_cinfo, &dir_attr);
-		nfs_refresh_inode(dir, &dir_attr);
-		nfs_refresh_inode(inode, &fattr);
-	}
 	return nfs4_map_errors(status);
 }
 

fs/nfs/nfs4xdr.c

@@ -116,6 +116,9 @@ static int nfs_stat_to_errno(int);
 #define encode_rename_maxsz	(op_encode_hdr_maxsz + \
 				2 * (1 + ((3 + NFS4_MAXNAMLEN) >> 2)))
 #define decode_rename_maxsz	(op_decode_hdr_maxsz + 5 + 5)
+#define encode_link_maxsz	(op_encode_hdr_maxsz + \
+				1 + ((3 + NFS4_MAXNAMLEN) >> 2))
+#define decode_link_maxsz	(op_decode_hdr_maxsz + 5)
 #define NFS4_enc_compound_sz	(1024)  /* XXX: large enough? */
 #define NFS4_dec_compound_sz	(1024)  /* XXX: large enough? */
 #define NFS4_enc_read_sz	(compound_encode_hdr_maxsz + \
@@ -291,6 +294,16 @@ static int nfs_stat_to_errno(int);
 				decode_savefh_maxsz + \
 				decode_putfh_maxsz + \
 				decode_rename_maxsz)
+#define NFS4_enc_link_sz	(compound_encode_hdr_maxsz + \
+				encode_putfh_maxsz + \
+				encode_savefh_maxsz + \
+				encode_putfh_maxsz + \
+				encode_link_maxsz)
+#define NFS4_dec_link_sz	(compound_decode_hdr_maxsz + \
+				decode_putfh_maxsz + \
+				decode_savefh_maxsz + \
+				decode_putfh_maxsz + \
+				decode_link_maxsz)
 
 
 
@@ -618,15 +631,14 @@ encode_getfh(struct xdr_stream *xdr)
 	return 0;
 }
 
-static int
-encode_link(struct xdr_stream *xdr, struct nfs4_link *link)
+static int encode_link(struct xdr_stream *xdr, const struct qstr *name)
 {
 	uint32_t *p;
 
-	RESERVE_SPACE(8 + link->ln_namelen);
+	RESERVE_SPACE(8 + name->len);
 	WRITE32(OP_LINK);
-	WRITE32(link->ln_namelen);
-	WRITEMEM(link->ln_name, link->ln_namelen);
+	WRITE32(name->len);
+	WRITEMEM(name->name, name->len);
 	
 	return 0;
 }
@@ -1112,9 +1124,6 @@ encode_compound(struct xdr_stream *xdr, struct nfs4_compound *cp, struct rpc_rqs
 		case OP_GETFH:
 			status = encode_getfh(xdr);
 			break;
-		case OP_LINK:
-			status = encode_link(xdr, &cp->ops[i].u.link);
-			break;
 		case OP_PUTFH:
 			status = encode_putfh(xdr, cp->ops[i].u.putfh.pf_fhandle);
 			break;
@@ -1266,6 +1275,30 @@ static int nfs4_xdr_enc_rename(struct rpc_rqst *req, uint32_t *p, const struct n
 	return status;
 }
 
+/*
+ * Encode LINK request
+ */
+static int nfs4_xdr_enc_link(struct rpc_rqst *req, uint32_t *p, const struct nfs4_link_arg *args)
+{
+	struct xdr_stream xdr;
+	struct compound_hdr hdr = {
+		.nops = 4,
+	};
+	int status;
+
+	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+	encode_compound_hdr(&xdr, &hdr);
+	if ((status = encode_putfh(&xdr, args->fh)) != 0)
+		goto out;
+	if ((status = encode_savefh(&xdr)) != 0)
+		goto out;
+	if ((status = encode_putfh(&xdr, args->dir_fh)) != 0)
+		goto out;
+	status = encode_link(&xdr, args->name);
+out:
+	return status;
+}
+
 /*
  * Encode GETATTR request
  */
@@ -2512,15 +2545,14 @@ static int decode_getfh(struct xdr_stream *xdr, struct nfs_fh *fh)
 	return 0;
 }
 
-static int
-decode_link(struct xdr_stream *xdr, struct nfs4_link *link)
+static int decode_link(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
 {
 	int status;
 	
 	status = decode_op_hdr(xdr, OP_LINK);
 	if (status)
 		return status;
-	return decode_change_info(xdr, link->ln_cinfo);
+	return decode_change_info(xdr, cinfo);
 }
 
 /*
@@ -2977,9 +3009,6 @@ decode_compound(struct xdr_stream *xdr, struct nfs4_compound *cp, struct rpc_rqs
 		case OP_GETFH:
 			status = decode_getfh(xdr, op->u.getfh.gf_fhandle);
 			break;
-		case OP_LINK:
-			status = decode_link(xdr, &op->u.link);
-			break;
 		case OP_PUTFH:
 			status = decode_putfh(xdr);
 			break;
@@ -3158,6 +3187,29 @@ static int nfs4_xdr_dec_rename(struct rpc_rqst *rqstp, uint32_t *p, struct nfs4_
 	return status;
 }
 
+/*
+ * Decode LINK response
+ */
+static int nfs4_xdr_dec_link(struct rpc_rqst *rqstp, uint32_t *p, struct nfs4_change_info *cinfo)
+{
+	struct xdr_stream xdr;
+	struct compound_hdr hdr;
+	int status;
+	
+	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+	if ((status = decode_compound_hdr(&xdr, &hdr)) != 0)
+		goto out;
+	if ((status = decode_putfh(&xdr)) != 0)
+		goto out;
+	if ((status = decode_savefh(&xdr)) != 0)
+		goto out;
+	if ((status = decode_putfh(&xdr)) != 0)
+		goto out;
+	status = decode_link(&xdr, cinfo);
+out:
+	return status;
+}
+
 /*
  * Decode GETATTR response
  */
@@ -3671,6 +3723,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
   PROC(LOOKUP_ROOT,	enc_lookup_root,	dec_lookup_root),
   PROC(REMOVE,		enc_remove,	dec_remove),
   PROC(RENAME,		enc_rename,	dec_rename),
+  PROC(LINK,		enc_link,	dec_link),
 };
 
 struct rpc_version		nfs_version4 = {

include/linux/nfs4.h

@@ -309,6 +309,7 @@ enum {
 	NFSPROC4_CLNT_LOOKUP_ROOT,
 	NFSPROC4_CLNT_REMOVE,
 	NFSPROC4_CLNT_RENAME,
+	NFSPROC4_CLNT_LINK,
 };
 
 #endif

include/linux/nfs_xdr.h

@@ -544,10 +544,10 @@ struct nfs4_getfh {
 	struct nfs_fh *			gf_fhandle;       /* response */
 };
 
-struct nfs4_link {
-	u32				ln_namelen;       /* request */
-	const char *			ln_name;          /* request */
-	struct nfs4_change_info *	ln_cinfo;         /* response */
+struct nfs4_link_arg {
+	const struct nfs_fh *		fh;
+	const struct nfs_fh *		dir_fh;
+	const struct qstr *		name;
 };
 
 struct nfs4_lookup_arg {
@@ -650,7 +650,6 @@ struct nfs4_op {
 		struct nfs4_create	create;
 		struct nfs4_getattr	getattr;
 		struct nfs4_getfh	getfh;
-		struct nfs4_link	link;
 		struct nfs4_open	open;
 		struct nfs4_open_confirm open_confirm;
 		struct nfs4_putfh	putfh;