NFSv4: don't put ACCESS in OPEN compound if O_EXCL

Don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
will return permission denied for all bits until close.

Fixes a regression due to commit 6168f62 (NFSv4: Add ACCESS operation to
OPEN compound)

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -862,9 +862,15 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
 	p->o_arg.fh = NFS_FH(dir);
 	p->o_arg.open_flags = flags;
 	p->o_arg.fmode = fmode & (FMODE_READ|FMODE_WRITE);
-	/* ask server to check for all possible rights as results are cached */
-	p->o_arg.access = NFS4_ACCESS_READ | NFS4_ACCESS_MODIFY |
-			  NFS4_ACCESS_EXTEND | NFS4_ACCESS_EXECUTE;
+	/* don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
+	 * will return permission denied for all bits until close */
+	if (!(flags & O_EXCL)) {
+		/* ask server to check for all possible rights as results
+		 * are cached */
+		p->o_arg.access = NFS4_ACCESS_READ | NFS4_ACCESS_MODIFY |
+				  NFS4_ACCESS_EXTEND | NFS4_ACCESS_EXECUTE;
+		p->o_res.access_request = p->o_arg.access;
+	}
 	p->o_arg.clientid = server->nfs_client->cl_clientid;
 	p->o_arg.id.create_time = ktime_to_ns(sp->so_seqid.create_time);
 	p->o_arg.id.uniquifier = sp->so_seqid.owner_id;

fs/nfs/nfs4xdr.c

@@ -2224,7 +2224,8 @@ static void nfs4_xdr_enc_open(struct rpc_rqst *req, struct xdr_stream *xdr,
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_open(xdr, args, &hdr);
 	encode_getfh(xdr, &hdr);
-	encode_access(xdr, args->access, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
 	encode_getfattr_open(xdr, args->bitmask, args->open_bitmap, &hdr);
 	encode_nops(&hdr);
 }
@@ -2261,7 +2262,8 @@ static void nfs4_xdr_enc_open_noattr(struct rpc_rqst *req,
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
 	encode_open(xdr, args, &hdr);
-	encode_access(xdr, args->access, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
 	encode_getfattr(xdr, args->bitmask, &hdr);
 	encode_nops(&hdr);
 }
@@ -6239,7 +6241,8 @@ static int nfs4_xdr_dec_open(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 	status = decode_getfh(xdr, &res->fh);
 	if (status)
 		goto out;
-	decode_access(xdr, &res->access_supported, &res->access_result);
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
 	decode_getfattr(xdr, res->f_attr, res->server);
 out:
 	return status;
@@ -6288,7 +6291,8 @@ static int nfs4_xdr_dec_open_noattr(struct rpc_rqst *rqstp,
 	status = decode_open(xdr, res);
 	if (status)
 		goto out;
-	decode_access(xdr, &res->access_supported, &res->access_result);
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
 	decode_getfattr(xdr, res->f_attr, res->server);
 out:
 	return status;

include/linux/nfs_xdr.h

@@ -369,6 +369,7 @@ struct nfs_openres {
 	struct nfs4_string	*owner;
 	struct nfs4_string	*group_owner;
 	struct nfs4_sequence_res	seq_res;
+	__u32			access_request;
 	__u32			access_supported;
 	__u32			access_result;
 };