nfsd: fix error values returned by nfsd4_lockt() when nfsd_open() fails

commit 04da6e9d upstream.

nfsd_open() already returns an NFS error value; only vfs_test_lock()
result needs to be fed through nfserrno().  Broken by commit 55ef12
(nfsd: Ensure nfsv4 calls the underlying filesystem on LOCKT)
three years ago...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

fs/nfsd/nfs4state.c

@@ -4080,16 +4080,14 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
  * vfs_test_lock.  (Arguably perhaps test_lock should be done with an
  * inode operation.)
  */
-static int nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
+static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
 {
 	struct file *file;
-	int err;
-
-	err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
-	if (err)
-		return err;
-	err = vfs_test_lock(file, lock);
-	nfsd_close(file);
+	__be32 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
+	if (!err) {
+		err = nfserrno(vfs_test_lock(file, lock));
+		nfsd_close(file);
+	}
 	return err;
 }
 
@@ -4103,7 +4101,6 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	struct inode *inode;
 	struct file_lock file_lock;
 	struct nfs4_lockowner *lo;
-	int error;
 	__be32 status;
 
 	if (locks_in_grace())
@@ -4149,12 +4146,10 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 	nfs4_transform_lock_offset(&file_lock);
 
-	status = nfs_ok;
-	error = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock);
-	if (error) {
-		status = nfserrno(error);
+	status = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock);
+	if (status)
 		goto out;
-	}
+
 	if (file_lock.fl_type != F_UNLCK) {
 		status = nfserr_denied;
 		nfs4_set_lock_denied(&file_lock, &lockt->lt_denied);