cxgbit: Abort the TCP connection in case of data out timeout

If DDP is programmed for a WRITE cmd and data out
timer gets expired then abort the TCP connection
before freeing the cmd to avoid any possibility of
DDP after freeing the cmd.
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/cxgbit/cxgbit.h

@@ -165,6 +165,7 @@ enum cxgbit_csk_flags {
 	CSK_LOGIN_PDU_DONE,
 	CSK_LOGIN_DONE,
 	CSK_DDP_ENABLE,
+	CSK_ABORT_RPL_WAIT,
 };
 
 struct cxgbit_sock_common {
@@ -321,6 +322,7 @@ int cxgbit_setup_np(struct iscsi_np *, struct sockaddr_storage *);
 int cxgbit_setup_conn_digest(struct cxgbit_sock *);
 int cxgbit_accept_np(struct iscsi_np *, struct iscsi_conn *);
 void cxgbit_free_np(struct iscsi_np *);
+void cxgbit_abort_conn(struct cxgbit_sock *csk);
 void cxgbit_free_conn(struct iscsi_conn *);
 extern cxgbit_cplhandler_func cxgbit_cplhandlers[NUM_CPL_CMDS];
 int cxgbit_get_login_rx(struct iscsi_conn *, struct iscsi_login *);

drivers/target/iscsi/cxgbit/cxgbit_cm.c

@@ -665,6 +665,46 @@ static int cxgbit_send_abort_req(struct cxgbit_sock *csk)
 	return cxgbit_l2t_send(csk->com.cdev, skb, csk->l2t);
 }
 
+static void
+__cxgbit_abort_conn(struct cxgbit_sock *csk, struct sk_buff *skb)
+{
+	__kfree_skb(skb);
+
+	if (csk->com.state != CSK_STATE_ESTABLISHED)
+		goto no_abort;
+
+	set_bit(CSK_ABORT_RPL_WAIT, &csk->com.flags);
+	csk->com.state = CSK_STATE_ABORTING;
+
+	cxgbit_send_abort_req(csk);
+
+	return;
+
+no_abort:
+	cxgbit_wake_up(&csk->com.wr_wait, __func__, CPL_ERR_NONE);
+	cxgbit_put_csk(csk);
+}
+
+void cxgbit_abort_conn(struct cxgbit_sock *csk)
+{
+	struct sk_buff *skb = alloc_skb(0, GFP_KERNEL | __GFP_NOFAIL);
+
+	cxgbit_get_csk(csk);
+	cxgbit_init_wr_wait(&csk->com.wr_wait);
+
+	spin_lock_bh(&csk->lock);
+	if (csk->lock_owner) {
+		cxgbit_skcb_rx_backlog_fn(skb) = __cxgbit_abort_conn;
+		__skb_queue_tail(&csk->backlogq, skb);
+	} else {
+		__cxgbit_abort_conn(csk, skb);
+	}
+	spin_unlock_bh(&csk->lock);
+
+	cxgbit_wait_for_reply(csk->com.cdev, &csk->com.wr_wait,
+			      csk->tid, 600, __func__);
+}
+
 void cxgbit_free_conn(struct iscsi_conn *conn)
 {
 	struct cxgbit_sock *csk = conn->context;
@@ -1709,12 +1749,17 @@ static void cxgbit_abort_req_rss(struct cxgbit_sock *csk, struct sk_buff *skb)
 
 static void cxgbit_abort_rpl_rss(struct cxgbit_sock *csk, struct sk_buff *skb)
 {
+	struct cpl_abort_rpl_rss *rpl = cplhdr(skb);
+
 	pr_debug("%s: csk %p; tid %u; state %d\n",
 		 __func__, csk, csk->tid, csk->com.state);
 
 	switch (csk->com.state) {
 	case CSK_STATE_ABORTING:
 		csk->com.state = CSK_STATE_DEAD;
+		if (test_bit(CSK_ABORT_RPL_WAIT, &csk->com.flags))
+			cxgbit_wake_up(&csk->com.wr_wait, __func__,
+				       rpl->status);
 		cxgbit_put_csk(csk);
 		break;
 	default:

drivers/target/iscsi/cxgbit/cxgbit_ddp.c

@@ -275,6 +275,14 @@ void cxgbit_release_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 			struct cxgbit_device *cdev = csk->com.cdev;
 			struct cxgbi_ppm *ppm = cdev2ppm(cdev);
 
+			/* Abort the TCP conn if DDP is not complete to
+			 * avoid any possibility of DDP after freeing
+			 * the cmd.
+			 */
+			if (unlikely(cmd->write_data_done !=
+				     cmd->se_cmd.data_length))
+				cxgbit_abort_conn(csk);
+
 			cxgbi_ppm_ppod_release(ppm, ttinfo->idx);
 
 			dma_unmap_sg(&ppm->pdev->dev, ttinfo->sgl,