diff --git a/iscsi-scst/README.iser b/iscsi-scst/README.iser
index ea5a57511..751213edc 100644
--- a/iscsi-scst/README.iser
+++ b/iscsi-scst/README.iser
@@ -25,9 +25,10 @@ Limitations:
 -------------
 * Bidirectional commands are not supported
 * Block size over 512KB is not supported
-* Maximum number of concurent login requests that can be handled is 127.
+* Maximum number of concurent login requests that can be handled is 127 by default.
   Note that there may be more connections, but only up to 127 login requests
-  can be handled at the same time.
+  can be handled at the same time. If you wish to increase this, load isert_scst with
+  module parameter isert_nr_devs set to the number of login requests you need to handle.
 
 
 Troubleshooting:
diff --git a/iscsi-scst/kernel/isert-scst/iser.h b/iscsi-scst/kernel/isert-scst/iser.h
index 95cdc4ec5..be8c8c9a2 100644
--- a/iscsi-scst/kernel/isert-scst/iser.h
+++ b/iscsi-scst/kernel/isert-scst/iser.h
@@ -66,6 +66,8 @@ struct isert_wr {
 #define ISER_SQ_SIZE		128
 #define ISER_MAX_WCE		2048
 
+#define ISER_MIN_SQ_SIZE	16
+
 struct isert_cmnd {
 	struct iscsi_cmnd	iscsi ____cacheline_aligned;
 
diff --git a/iscsi-scst/kernel/isert-scst/iser_buf.c b/iscsi-scst/kernel/isert-scst/iser_buf.c
index 32daeb377..dd418f0de 100644
--- a/iscsi-scst/kernel/isert-scst/iser_buf.c
+++ b/iscsi-scst/kernel/isert-scst/iser_buf.c
@@ -293,9 +293,11 @@ void isert_wr_release(struct isert_wr *wr)
 		struct isert_device *isert_dev = wr->isert_dev;
 		struct ib_device *ib_dev;
 
-		ib_dev = isert_dev->ib_dev;
-		ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
-				isert_buf->dma_dir);
+		if (isert_buf->sg_cnt) {
+			ib_dev = isert_dev->ib_dev;
+			ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
+					isert_buf->dma_dir);
+		}
 		isert_buf_release(isert_buf);
 	}
 	memset(wr, 0, sizeof(*wr));
diff --git a/iscsi-scst/kernel/isert-scst/iser_rdma.c b/iscsi-scst/kernel/isert-scst/iser_rdma.c
index 0c669e611..03dc2afa9 100644
--- a/iscsi-scst/kernel/isert-scst/iser_rdma.c
+++ b/iscsi-scst/kernel/isert-scst/iser_rdma.c
@@ -359,6 +359,7 @@ static void isert_rdma_rd_completion_handler(struct isert_wr *wr)
 
 	ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
 			isert_buf->dma_dir);
+	isert_buf->sg_cnt = 0;
 
 	isert_data_out_ready(&wr->pdu->iscsi);
 }
@@ -371,6 +372,7 @@ static void isert_rdma_wr_completion_handler(struct isert_wr *wr)
 
 	ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
 			isert_buf->dma_dir);
+	isert_buf->sg_cnt = 0;
 
 	isert_data_in_sent(&wr->pdu->iscsi);
 }
@@ -544,9 +546,9 @@ static void isert_handle_wc_error(struct ib_wc *wc)
 		break;
 	case ISER_WR_RDMA_READ:
 		if (isert_buf->sg_cnt != 0) {
-			isert_buf->sg_cnt = 0;
 			ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
 				isert_buf->dma_dir);
+			isert_buf->sg_cnt = 0;
 		}
 		isert_pdu_err(&isert_pdu->iscsi);
 		break;
@@ -555,9 +557,9 @@ static void isert_handle_wc_error(struct ib_wc *wc)
 		break;
 	case ISER_WR_RDMA_WRITE:
 		if (isert_buf->sg_cnt != 0) {
-			isert_buf->sg_cnt = 0;
 			ib_dma_unmap_sg(ib_dev, isert_buf->sg, isert_buf->sg_cnt,
 				isert_buf->dma_dir);
+			isert_buf->sg_cnt = 0;
 		}
 		/* RDMA-WR and SEND response of a READ task
 		   are sent together, so when receiving RDMA-WR error,
@@ -978,6 +980,7 @@ static int isert_conn_qp_create(struct isert_connection *isert_conn)
 	struct ib_qp_init_attr qp_attr;
 	int err;
 	int cq_idx;
+	int max_wr = ISER_MAX_WCE;
 
 	TRACE_ENTRY();
 
@@ -989,8 +992,6 @@ static int isert_conn_qp_create(struct isert_connection *isert_conn)
 	qp_attr.qp_context = isert_conn;
 	qp_attr.send_cq = isert_dev->cq_desc[cq_idx].cq;
 	qp_attr.recv_cq = isert_dev->cq_desc[cq_idx].cq;
-	qp_attr.cap.max_send_wr = ISER_MAX_WCE;
-	qp_attr.cap.max_recv_wr = ISER_MAX_WCE;
 
 	isert_conn->cq_desc = &isert_dev->cq_desc[cq_idx];
 
@@ -1014,11 +1015,24 @@ static int isert_conn_qp_create(struct isert_connection *isert_conn)
 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 	qp_attr.qp_type = IB_QPT_RC;
 
-	err = rdma_create_qp(cm_id, isert_dev->pd, &qp_attr);
-	if (unlikely(err)) {
-		pr_err("Failed to create qp, err:%d\n", err);
-		goto fail_create_qp;
-	}
+	do {
+		if (max_wr < ISER_MIN_SQ_SIZE) {
+			pr_err("Failed to create qp, not enough memory\n");
+			goto fail_create_qp;
+		}
+
+		qp_attr.cap.max_send_wr = max_wr;
+		qp_attr.cap.max_recv_wr = max_wr;
+
+		err = rdma_create_qp(cm_id, isert_dev->pd, &qp_attr);
+		if (err && err != -ENOMEM) {
+			pr_err("Failed to create qp, err:%d\n", err);
+			goto fail_create_qp;
+		}
+
+		max_wr /= 2;
+	} while (err == -ENOMEM);
+
 	isert_conn->qp = cm_id->qp;
 
 	pr_info("iser created cm_id:%p qp:0x%X\n", cm_id, cm_id->qp->qp_num);