RDMA/cxgb4: Don't change QP state outside EP lock

Concurrent ingress CLOSE and ULP ABORT operations causes a crash due
to a race condition where the close path releases the EP lock and then
tries to move the QP state to CLOSED.  This must be done inside the EP
lock to avoid the race.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 9d8dcfa..d235810 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -1466,7 +1466,7 @@
 	struct c4iw_qp_attributes attrs;
 	int disconnect = 1;
 	int release = 0;
-	int closing = 0;
+	int abort = 0;
 	struct tid_info *t = dev->rdev.lldi.tids;
 	unsigned int tid = GET_TID(hdr);
 
@@ -1507,8 +1507,11 @@
 	case FPDU_MODE:
 		start_ep_timer(ep);
 		__state_set(&ep->com, CLOSING);
-		closing = 1;
+		attrs.next_state = C4IW_QP_STATE_CLOSING;
+		abort = c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
+				       C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
 		peer_close_upcall(ep);
+		disconnect = 1;
 		break;
 	case ABORTING:
 		disconnect = 0;
@@ -1536,11 +1539,6 @@
 		BUG_ON(1);
 	}
 	mutex_unlock(&ep->com.mutex);
-	if (closing) {
-		attrs.next_state = C4IW_QP_STATE_CLOSING;
-		c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
-			       C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
-	}
 	if (disconnect)
 		c4iw_ep_disconnect(ep, 0, GFP_KERNEL);
 	if (release)
@@ -1710,14 +1708,14 @@
 	ep = lookup_tid(t, tid);
 	BUG_ON(!ep);
 
-	if (ep->com.qp) {
+	if (ep && ep->com.qp) {
 		printk(KERN_WARNING MOD "TERM received tid %u qpid %u\n", tid,
 		       ep->com.qp->wq.sq.qid);
 		attrs.next_state = C4IW_QP_STATE_TERMINATE;
 		c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
 			       C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
 	} else
-		printk(KERN_WARNING MOD "TERM received tid %u no qp\n", tid);
+		printk(KERN_WARNING MOD "TERM received tid %u no ep/qp\n", tid);
 
 	return 0;
 }
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 9f6166f..8e16eb2 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -161,8 +161,8 @@
 		}
 	} while (!wr_waitp->done);
 	if (wr_waitp->ret)
-		printk(KERN_WARNING MOD "%s: FW reply %d tid %u qpid %u\n",
-		       pci_name(rdev->lldi.pdev), wr_waitp->ret, hwtid, qpid);
+		PDBG("%s: FW reply %d tid %u qpid %u\n",
+		     pci_name(rdev->lldi.pdev), wr_waitp->ret, hwtid, qpid);
 	return wr_waitp->ret;
 }
 
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index 70a5a3c..a1824a5 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -1210,7 +1210,6 @@
 			if (ret) {
 				if (internal)
 					c4iw_get_ep(&qhp->ep->com);
-				disconnect = abort = 1;
 				goto err;
 			}
 			break;