nfsd4: fix delegation cleanup on error

We're not cleaning up everything we need to on error.  In particular,
we're not removing our lease.  Among other problems this can cause the
struct nfs4_file used as fl_owner to be referenced after it has been
destroyed.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -418,6 +418,8 @@ nfs4_put_delegation(struct nfs4_delegation *dp)
 
 static void nfs4_put_deleg_lease(struct nfs4_file *fp)
 {
+	if (!fp->fi_lease)
+		return;
 	if (atomic_dec_and_test(&fp->fi_delegees)) {
 		vfs_setlease(fp->fi_deleg_file, F_UNLCK, &fp->fi_lease);
 		fp->fi_lease = NULL;
@@ -440,9 +442,11 @@ unhash_delegation(struct nfs4_delegation *dp)
 	list_del_init(&dp->dl_perfile);
 	list_del_init(&dp->dl_recall_lru);
 	spin_unlock(&recall_lock);
-	nfs4_put_deleg_lease(dp->dl_file);
-	put_nfs4_file(dp->dl_file);
-	dp->dl_file = NULL;
+	if (dp->dl_file) {
+		nfs4_put_deleg_lease(dp->dl_file);
+		put_nfs4_file(dp->dl_file);
+		dp->dl_file = NULL;
+	}
 }
 
 
@@ -3060,33 +3064,22 @@ static int nfs4_setlease(struct nfs4_delegation *dp)
 
 static int nfs4_set_delegation(struct nfs4_delegation *dp, struct nfs4_file *fp)
 {
-	int status;
-
 	if (fp->fi_had_conflict)
 		return -EAGAIN;
 	get_nfs4_file(fp);
 	dp->dl_file = fp;
-	if (!fp->fi_lease) {
-		status = nfs4_setlease(dp);
-		if (status)
-			goto out_free;
-		return 0;
-	}
+	if (!fp->fi_lease)
+		return nfs4_setlease(dp);
 	spin_lock(&recall_lock);
+	atomic_inc(&fp->fi_delegees);
 	if (fp->fi_had_conflict) {
 		spin_unlock(&recall_lock);
-		status = -EAGAIN;
-		goto out_free;
+		return -EAGAIN;
 	}
-	atomic_inc(&fp->fi_delegees);
 	list_add(&dp->dl_perfile, &fp->fi_delegations);
 	spin_unlock(&recall_lock);
 	list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations);
 	return 0;
-out_free:
-	put_nfs4_file(fp);
-	dp->dl_file = fp;
-	return status;
 }
 
 static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
@@ -3173,8 +3166,7 @@ nfs4_open_delegation(struct net *net, struct svc_fh *fh,
 	open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
 	return;
 out_free:
-	remove_stid(&dp->dl_stid);
-	nfs4_put_delegation(dp);
+	destroy_delegation(dp);
 out_no_deleg:
 	open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE;
 	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&