diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a33dac7c2e2f..c6e0e2b26f60 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2653,6 +2653,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
 	/* We have read all the blocks in this stripe and now we need to
 	 * copy some of them into a target stripe for expand.
 	 */
+	struct dma_async_tx_descriptor *tx = NULL;
 	clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
 	for (i = 0; i < sh->disks; i++)
 		if (i != sh->pd_idx && (r6s && i != r6s->qd_idx)) {
@@ -2678,9 +2679,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
 				release_stripe(sh2);
 				continue;
 			}
-			memcpy(page_address(sh2->dev[dd_idx].page),
-			       page_address(sh->dev[i].page),
-			       STRIPE_SIZE);
+
+			/* place all the copies on one channel */
+			tx = async_memcpy(sh2->dev[dd_idx].page,
+				sh->dev[i].page, 0, 0, STRIPE_SIZE,
+				ASYNC_TX_DEP_ACK, tx, NULL, NULL);
+
 			set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
 			set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
 			for (j = 0; j < conf->raid_disks; j++)
@@ -2693,6 +2697,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
 				set_bit(STRIPE_HANDLE, &sh2->state);
 			}
 			release_stripe(sh2);
+
+			/* done submitting copies, wait for them to complete */
+			if (i + 1 >= sh->disks) {
+				async_tx_ack(tx);
+				dma_wait_for_async_tx(tx);
+			}
 		}
 }
 
@@ -2931,18 +2941,34 @@ static void handle_stripe5(struct stripe_head *sh)
 		}
 	}
 
-	if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
+	/* Finish postxor operations initiated by the expansion
+	 * process
+	 */
+	if (test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete) &&
+		!test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending)) {
+
+		clear_bit(STRIPE_EXPANDING, &sh->state);
+
+		clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
+		clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
+		clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
+
+		for (i = conf->raid_disks; i--; ) {
+			set_bit(R5_Wantwrite, &sh->dev[i].flags);
+			if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
+				sh->ops.count++;
+		}
+	}
+
+	if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
+		!test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
 		/* Need to write out all blocks after computing parity */
 		sh->disks = conf->raid_disks;
-		sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
-		compute_parity5(sh, RECONSTRUCT_WRITE);
-		for (i = conf->raid_disks; i--; ) {
-			set_bit(R5_LOCKED, &sh->dev[i].flags);
-			s.locked++;
-			set_bit(R5_Wantwrite, &sh->dev[i].flags);
-		}
-		clear_bit(STRIPE_EXPANDING, &sh->state);
-	} else if (s.expanded) {
+		sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
+			conf->raid_disks);
+		s.locked += handle_write_operations5(sh, 0, 1);
+	} else if (s.expanded &&
+		!test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
 		clear_bit(STRIPE_EXPAND_READY, &sh->state);
 		atomic_dec(&conf->reshape_stripes);
 		wake_up(&conf->wait_for_overlap);