net/smc: put slot when connection is killed

To get a send slot smc_wr_tx_get_free_slot() is called, which might
wait for a free slot. When smc_wr_tx_get_free_slot() returns there is a
check if the connection was killed in the meantime. In that case don't
only return an error, but also put back the free slot.

Fixes: b2900980 ("net/smc: cancel send and receive for terminated socket")
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_cdc.c

@@ -66,9 +66,13 @@ int smc_cdc_get_free_slot(struct smc_connection *conn,
 	rc = smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf,
 				     wr_rdma_buf,
 				     (struct smc_wr_tx_pend_priv **)pend);
-	if (conn->killed)
+	if (conn->killed) {
 		/* abnormal termination */
+		if (!rc)
+			smc_wr_tx_put_slot(link,
+					   (struct smc_wr_tx_pend_priv *)pend);
 		rc = -EPIPE;
+	}
 	return rc;
 }