Merge pull request #54 from plieven/nop+queue-fixes

Nop+queue fixes

include/iscsi-private.h

@@ -95,6 +95,7 @@ struct iscsi_context {
 	int is_loggedin;
 	int is_reconnecting;
 	int bind_interfaces_cnt;
+	int nops_in_flight;
 
 	int chap_a;
 	int chap_i;
@@ -122,7 +123,7 @@ struct iscsi_context {
 	int no_auto_reconnect;
 	int reconnect_deferred;
 	int reconnect_max_retries;
-	
+
 	int log_level;
 	iscsi_log_fn log_fn;
 
@@ -217,7 +218,8 @@ struct iscsi_pdu {
 
 	struct iscsi_data outdata; /* Header for PDU to send */
 	uint32_t out_offset;       /* Offset into data-out iovector */
-	uint32_t out_len;          /* Amount of data to sent */
+	uint32_t out_len;          /* Amount of data to sent starting at out_offset */
+	uint32_t out_written;      /* Number of bytes written to socket */
 
 	struct iscsi_data indata;
 

include/iscsi.h

@@ -35,6 +35,7 @@ struct sockaddr;
 
 /* FEATURES */
 #define LIBISCSI_FEATURE_IOVECTOR (1)
+#define LIBISCSI_FEATURE_NOP_COUNTER (1)
 
 #define MAX_STRING_SIZE (255)
 
@@ -474,10 +475,17 @@ struct iscsi_discovery_address {
  *                            structure containing the data returned from
  *                            the server.
  *    ISCSI_STATUS_CANCELLED: Discovery was aborted. Command_data is NULL.
+ * 
+ * The callback may be NULL if you only want to let libiscsi count the in-flight
+ * NOPs.
  */
 EXTERN int iscsi_nop_out_async(struct iscsi_context *iscsi, iscsi_command_cb cb,
 			unsigned char *data, int len, void *private_data);
 
+
+/* read out the number of consecutive nop outs that did not receive an answer */
+EXTERN int iscsi_get_nops_in_flight(struct iscsi_context *iscsi);
+
 struct scsi_task;
 
 enum iscsi_task_mgmt_funcs {

lib/connect.c

@@ -288,6 +288,12 @@ try_again:
 		goto try_again;
 	}
 
+	while (old_iscsi->outqueue) {
+		struct iscsi_pdu *pdu = old_iscsi->outqueue;
+		SLIST_REMOVE(&old_iscsi->outqueue, pdu);
+		SLIST_ADD_END(&old_iscsi->waitpdu, pdu);
+	}
+
 	while (old_iscsi->waitpdu) {
 		struct iscsi_pdu *pdu = old_iscsi->waitpdu;
 
@@ -296,29 +302,6 @@ try_again:
 			continue;
 		}
 
-		pdu->itt   = iscsi_itt_post_increment(iscsi);
-		iscsi_pdu_set_itt(pdu, pdu->itt);
-
-		/* do not increase cmdsn for PDUs marked for immediate delivery
-		 * this will result in a protocol error */
-		pdu->cmdsn = (pdu->outdata.data[0] & ISCSI_PDU_IMMEDIATE)?iscsi->cmdsn:iscsi->cmdsn++;
-		iscsi_pdu_set_cmdsn(pdu, pdu->cmdsn);
-
-		iscsi_pdu_set_expstatsn(pdu, iscsi->statsn);
-		iscsi->statsn++;
-
-		pdu->written = 0;
-		iscsi_add_to_outqueue(iscsi, pdu);
-	}
-
-	while (old_iscsi->outqueue) {
-		struct iscsi_pdu *pdu = old_iscsi->outqueue;
-
-		SLIST_REMOVE(&old_iscsi->outqueue, pdu);
-		if (pdu->itt == 0xffffffff) {
-			continue;
-		}
-
 		if (pdu->flags & ISCSI_PDU_DROP_ON_RECONNECT) {
 			/* We dont want to requeue things like DATA-OUT since these guys
 			 * will be reissued automatically anyway once the corresponding
@@ -341,6 +324,7 @@ try_again:
 		iscsi->statsn++;
 
 		pdu->written = 0;
+		pdu->out_written = 0;
 		iscsi_add_to_outqueue(iscsi, pdu);
 	}
 

lib/libiscsi.def

@@ -14,6 +14,7 @@ iscsi_get_fd
 iscsi_get_lba_status_sync
 iscsi_get_lba_status_task
 iscsi_get_target_address
+iscsi_get_nops_in_flight
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in

lib/libiscsi.syms

@@ -12,6 +12,7 @@ iscsi_get_fd
 iscsi_get_lba_status_sync
 iscsi_get_lba_status_task
 iscsi_get_target_address
+iscsi_get_nops_in_flight
 iscsi_inquiry_sync
 iscsi_inquiry_task
 iscsi_is_logged_in

lib/nop.c

@@ -81,6 +81,8 @@ iscsi_nop_out_async(struct iscsi_context *iscsi, iscsi_command_cb cb,
 		return -1;
 	}
 
+	iscsi->nops_in_flight++;
+
 	return 0;
 }
 
@@ -130,6 +132,12 @@ iscsi_process_nop_out_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 {
 	struct iscsi_data data;
 
+	iscsi->nops_in_flight = 0;
+
+	if (pdu->callback == NULL) {
+		return 0;
+	}
+
 	data.data = NULL;
 	data.size = 0;
 
@@ -137,7 +145,13 @@ iscsi_process_nop_out_reply(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 		data.data = in->data;
 		data.size = in->data_pos;
 	}
+	
 	pdu->callback(iscsi, SCSI_STATUS_GOOD, &data, pdu->private_data);
 
 	return 0;
 }
+
+int iscsi_get_nops_in_flight(struct iscsi_context *iscsi)
+{
+	return iscsi->nops_in_flight;
+}

lib/socket.c

@@ -517,11 +517,11 @@ iscsi_write_to_socket(struct iscsi_context *iscsi)
 		}
 
 		/* Write any iovectors that might have been passed to us */
-		while (pdu->out_len > 0) {
+		while (pdu->out_written < pdu->out_len) {
 			unsigned char *buf;
 
-			count = pdu->out_len;
-			buf = iscsi_get_user_out_buffer(iscsi, pdu, pdu->out_offset, &count);
+			count = pdu->out_len - pdu->out_written;
+			buf = iscsi_get_user_out_buffer(iscsi, pdu, pdu->out_offset + pdu->out_written, &count);
 			if (buf == NULL) {
 				iscsi_set_error(iscsi, "Can't find iovector data for DATA-OUT");
 				return -1;
@@ -539,16 +539,13 @@ iscsi_write_to_socket(struct iscsi_context *iscsi)
 						"socket :%d", errno);
 				return -1;
 			}
-			pdu->out_offset += count;
-			pdu->out_len    -= count;
+			pdu->out_written += count;
 		}
 
-		if (pdu->written == total) {
-			if (pdu->flags & ISCSI_PDU_DELETE_WHEN_SENT) {
-				iscsi_free_pdu(iscsi, pdu);
-			}
-			iscsi->outqueue_current = NULL;
+		if (pdu->flags & ISCSI_PDU_DELETE_WHEN_SENT) {
+			iscsi_free_pdu(iscsi, pdu);
 		}
+		iscsi->outqueue_current = NULL;
 	}
 	return 0;
 }