isert: Print error to user if QueuedCommands value exceeds supported maximum

Signed-off-by: Yan Burman <yanb@mellanox.com>

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/iser@5341 d57e44dd-8a1f-0410-8b47-8ef2f437770f

iscsi-scst/kernel/isert-scst/iser.h

@@ -58,6 +58,7 @@ struct isert_wr {
 #define ISER_MAX_RDMAS		5
 
 #define ISER_SQ_SIZE		128
+#define ISER_MAX_WCE		2048
 
 struct isert_cmnd {
 	struct iscsi_cmnd	iscsi ____cacheline_aligned;

iscsi-scst/kernel/isert-scst/iser_pdu.c

@@ -381,6 +381,13 @@ int isert_alloc_conn_resources(struct isert_connection *isert_conn)
 	isert_conn->repost_threshold = 32;
 	to_alloc = isert_conn->queue_depth * 2 + isert_conn->repost_threshold;
 
+	if (unlikely(to_alloc > ISER_MAX_WCE)) {
+		pr_err("QueuedCommands larger than %d not supported\n",
+		       (ISER_MAX_WCE - isert_conn->repost_threshold) / 2);
+		err = -EINVAL;
+		goto out;
+	}
+
 	for (i = 0; i < to_alloc; i++) {
 		pdu = isert_rx_pdu_alloc(isert_conn, t_datasz);
 		if (unlikely(!pdu)) {

iscsi-scst/kernel/isert-scst/iser_rdma.c

@@ -41,7 +41,6 @@
 #include "iser_datamover.h"
 
 #define ISER_CQ_ENTRIES		(128 * 1024)
-#define ISER_MAX_WCE		2048
 #define ISER_LISTEN_BACKLOG	8
 
 static DEFINE_MUTEX(dev_list_mutex);