Patch "iscsi-target: Fix iscsit_start_kthreads failure OOPs" has been added to the 3.14-stable tree

@@ -3937,7 +3937,13 @@ get_immediate:
 	}
 
 transport_err:
-	iscsit_take_action_for_connection_exit(conn);
+	/*
+	 * Avoid the normal connection failure code-path if this connection
+	 * is still within LOGIN mode, and iscsi_np process context is
+	 * responsible for cleaning up the early connection failure.
+	 */
+	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
+		iscsit_take_action_for_connection_exit(conn);
 out:
 	return 0;
 }

@@ -4023,7 +4029,7 @@ reject:
 
 int iscsi_target_rx_thread(void *arg)
 {
-	int ret;
+	int ret, rc;
 	u8 buffer[ISCSI_HDR_LEN], opcode;
 	u32 checksum = 0, digest = 0;
 	struct iscsi_conn *conn = arg;

@@ -4033,10 +4039,16 @@ int iscsi_target_rx_thread(void *arg)
 	 * connection recovery / failure event can be triggered externally.
 	 */
 	allow_signal(SIGINT);
+	/*
+	 * Wait for iscsi_post_login_handler() to complete before allowing
+	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
+	 */
+	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
+	if (rc < 0)
+		return 0;
 
 	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {
 		struct completion comp;
-		int rc;
 
 		init_completion(&comp);
 		rc = wait_for_completion_interruptible(&comp);

@@ -604,6 +604,7 @@ struct iscsi_conn {
 	int			bitmap_id;
 	int			rx_thread_active;
 	struct task_struct	*rx_thread;
+	struct completion	rx_login_comp;
 	int			tx_thread_active;
 	struct task_struct	*tx_thread;
 	/* list_head for session connection list */

110 lines not on this page · raw message

@@ -12,7 +12,8 @@ extern int iscsit_accept_np(struct iscsi
 extern int iscsit_get_login_rx(struct iscsi_conn *, struct iscsi_login *);
 extern int iscsit_put_login_tx(struct iscsi_conn *, struct iscsi_login *, u32);
 extern void iscsit_free_conn(struct iscsi_np *, struct iscsi_conn *);
-extern int iscsi_post_login_handler(struct iscsi_np *, struct iscsi_conn *, u8);
+extern int iscsit_start_kthreads(struct iscsi_conn *);
+extern void iscsi_post_login_handler(struct iscsi_np *, struct iscsi_conn *, u8);
 extern void iscsi_target_login_sess_out(struct iscsi_conn *, struct iscsi_np *,
 				bool, bool);
 extern int iscsi_target_login_thread(void *);

@@ -17,6 +17,7 @@
  ******************************************************************************/
 
 #include <linux/ctype.h>
+#include <linux/kthread.h>
 #include <scsi/iscsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>

@@ -361,10 +362,24 @@ static int iscsi_target_do_tx_login_io(s
 		ntohl(login_rsp->statsn), login->rsp_length);
 
 	padding = ((-login->rsp_length) & 3);
+	/*
+	 * Before sending the last login response containing the transition
+	 * bit for full-feature-phase, go ahead and start up TX/RX threads
+	 * now to avoid potential resource allocation failures after the
+	 * final login response has been sent.
+	 */
+	if (login->login_complete) {
+		int rc = iscsit_start_kthreads(conn);
+		if (rc) {
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+					    ISCSI_LOGIN_STATUS_NO_RESOURCES);
+			return -1;
+		}
+	}
 
 	if (conn->conn_transport->iscsit_put_login_tx(conn, login,
 					login->rsp_length + padding) < 0)
-		return -1;
+		goto err;
 
 	login->rsp_length		= 0;
 	mutex_lock(&sess->cmdsn_mutex);

@@ -373,6 +388,23 @@ static int iscsi_target_do_tx_login_io(s
 	mutex_unlock(&sess->cmdsn_mutex);
 
 	return 0;
+
+err:
+	if (login->login_complete) {
+		if (conn->rx_thread && conn->rx_thread_active) {
+			send_sig(SIGINT, conn->rx_thread, 1);
+			kthread_stop(conn->rx_thread);
+		}
+		if (conn->tx_thread && conn->tx_thread_active) {
+			send_sig(SIGINT, conn->tx_thread, 1);
+			kthread_stop(conn->tx_thread);
+		}
+		spin_lock(&iscsit_global->ts_bitmap_lock);
+		bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
+				      get_order(1));
+		spin_unlock(&iscsit_global->ts_bitmap_lock);
+	}
+	return -1;
 }
 
 static void iscsi_target_sk_data_ready(struct sock *sk, int count)