NFSv4: Clean up open delegation return structure

Instead of having the fields open coded in the struct nfs_openres,
add a separate structure for them so that we can reuse that code
for the WANT_DELEGATION case.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -1960,6 +1960,13 @@ nfs4_opendata_check_deleg(struct nfs4_opendata *data, struct nfs4_state *state)
 	struct nfs_delegation *delegation;
 	int delegation_flags = 0;
 
+	switch (data->o_res.delegation.open_delegation_type) {
+	case NFS4_OPEN_DELEGATE_READ:
+	case NFS4_OPEN_DELEGATE_WRITE:
+		break;
+	default:
+		return;
+	};
 	rcu_read_lock();
 	delegation = rcu_dereference(NFS_I(state->inode)->delegation);
 	if (delegation)
@@ -1979,19 +1986,19 @@ nfs4_opendata_check_deleg(struct nfs4_opendata *data, struct nfs4_state *state)
 	if ((delegation_flags & 1UL<<NFS_DELEGATION_NEED_RECLAIM) == 0)
 		nfs_inode_set_delegation(state->inode,
 				data->owner->so_cred,
-				data->o_res.delegation_type,
-				&data->o_res.delegation,
-				data->o_res.pagemod_limit);
+				data->o_res.delegation.type,
+				&data->o_res.delegation.stateid,
+				data->o_res.delegation.pagemod_limit);
 	else
 		nfs_inode_reclaim_delegation(state->inode,
 				data->owner->so_cred,
-				data->o_res.delegation_type,
-				&data->o_res.delegation,
-				data->o_res.pagemod_limit);
+				data->o_res.delegation.type,
+				&data->o_res.delegation.stateid,
+				data->o_res.delegation.pagemod_limit);
 
-	if (data->o_res.do_recall)
+	if (data->o_res.delegation.do_recall)
 		nfs_async_inode_return_delegation(state->inode,
-						  &data->o_res.delegation);
+						  &data->o_res.delegation.stateid);
 }
 
 /*
@@ -2015,7 +2022,6 @@ _nfs4_opendata_reclaim_to_nfs4_state(struct nfs4_opendata *data)
 	if (ret)
 		return ERR_PTR(ret);
 
-	if (data->o_res.delegation_type != 0)
 	nfs4_opendata_check_deleg(data, state);
 
 	if (!update_open_stateid(state, &data->o_res.stateid,
@@ -2083,7 +2089,7 @@ _nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
 	if (IS_ERR(state))
 		goto out;
 
-	if (data->o_res.delegation_type != 0)
+	if (data->o_res.delegation.type != 0)
 		nfs4_opendata_check_deleg(data, state);
 	if (!update_open_stateid(state, &data->o_res.stateid,
 				NULL, data->o_arg.fmode)) {
@@ -3111,7 +3117,7 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
 		if (!opendata->rpc_done)
 			break;
-		if (opendata->o_res.delegation_type != 0)
+		if (opendata->o_res.delegation.type != 0)
 			dir_verifier = nfs_save_change_attribute(dir);
 		nfs_set_verifier(dentry, dir_verifier);
 	}

fs/nfs/nfs4xdr.c

@@ -5148,13 +5148,12 @@ static int decode_space_limit(struct xdr_stream *xdr,
 }
 
 static int decode_rw_delegation(struct xdr_stream *xdr,
-		uint32_t delegation_type,
-		struct nfs_openres *res)
+		struct nfs4_open_delegation *res)
 {
 	__be32 *p;
 	int status;
 
-	status = decode_delegation_stateid(xdr, &res->delegation);
+	status = decode_delegation_stateid(xdr, &res->stateid);
 	if (unlikely(status))
 		return status;
 	p = xdr_inline_decode(xdr, 4);
@@ -5162,52 +5161,53 @@ static int decode_rw_delegation(struct xdr_stream *xdr,
 		return -EIO;
 	res->do_recall = be32_to_cpup(p);
 
-	switch (delegation_type) {
+	switch (res->open_delegation_type) {
 	case NFS4_OPEN_DELEGATE_READ:
-		res->delegation_type = FMODE_READ;
+		res->type = FMODE_READ;
 		break;
 	case NFS4_OPEN_DELEGATE_WRITE:
-		res->delegation_type = FMODE_WRITE|FMODE_READ;
+		res->type = FMODE_WRITE|FMODE_READ;
 		if (decode_space_limit(xdr, &res->pagemod_limit) < 0)
 				return -EIO;
 	}
 	return decode_ace(xdr, NULL);
 }
 
-static int decode_no_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
+static int decode_no_delegation(struct xdr_stream *xdr,
+		struct nfs4_open_delegation *res)
 {
 	__be32 *p;
-	uint32_t why_no_delegation;
 
 	p = xdr_inline_decode(xdr, 4);
 	if (unlikely(!p))
 		return -EIO;
-	why_no_delegation = be32_to_cpup(p);
-	switch (why_no_delegation) {
+	res->why_no_delegation = be32_to_cpup(p);
+	switch (res->why_no_delegation) {
 		case WND4_CONTENTION:
 		case WND4_RESOURCE:
-			xdr_inline_decode(xdr, 4);
-			/* Ignore for now */
+			p = xdr_inline_decode(xdr, 4);
+			if (unlikely(!p))
+				return -EIO;
+			res->will_notify = be32_to_cpup(p);
 	}
 	return 0;
 }
 
-static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
+static int decode_delegation(struct xdr_stream *xdr,
+		struct nfs4_open_delegation *res)
 {
 	__be32 *p;
-	uint32_t delegation_type;
 
 	p = xdr_inline_decode(xdr, 4);
 	if (unlikely(!p))
 		return -EIO;
-	delegation_type = be32_to_cpup(p);
-	res->delegation_type = 0;
-	switch (delegation_type) {
+	res->open_delegation_type = be32_to_cpup(p);
+	switch (res->open_delegation_type) {
 	case NFS4_OPEN_DELEGATE_NONE:
 		return 0;
 	case NFS4_OPEN_DELEGATE_READ:
 	case NFS4_OPEN_DELEGATE_WRITE:
-		return decode_rw_delegation(xdr, delegation_type, res);
+		return decode_rw_delegation(xdr, res);
 	case NFS4_OPEN_DELEGATE_NONE_EXT:
 		return decode_no_delegation(xdr, res);
 	}
@@ -5248,7 +5248,7 @@ static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
 	for (; i < NFS4_BITMAP_SIZE; i++)
 		res->attrset[i] = 0;
 
-	return decode_delegation(xdr, res);
+	return decode_delegation(xdr, &res->delegation);
 xdr_error:
 	dprintk("%s: Bitmap too large! Length = %u\n", __func__, bmlen);
 	return -EIO;

include/linux/nfs_xdr.h

@@ -449,6 +449,22 @@ struct stateowner_id {
 	__u32	uniquifier;
 };
 
+struct nfs4_open_delegation {
+	__u32 open_delegation_type;
+	union {
+		struct {
+			fmode_t			type;
+			__u32			do_recall;
+			nfs4_stateid		stateid;
+			unsigned long		pagemod_limit;
+		};
+		struct {
+			__u32			why_no_delegation;
+			__u32			will_notify;
+		};
+	};
+};
+
 /*
  * Arguments to the open call.
  */
@@ -490,13 +506,10 @@ struct nfs_openres {
 	struct nfs_fattr *      f_attr;
 	struct nfs_seqid *	seqid;
 	const struct nfs_server *server;
-	fmode_t			delegation_type;
-	nfs4_stateid		delegation;
-	unsigned long		pagemod_limit;
-	__u32			do_recall;
 	__u32			attrset[NFS4_BITMAP_SIZE];
 	struct nfs4_string	*owner;
 	struct nfs4_string	*group_owner;
+	struct nfs4_open_delegation	delegation;
 	__u32			access_request;
 	__u32			access_supported;
 	__u32			access_result;