smb: server: let recv_done() consistently call put_recvmsg/smb_direct_disconnect_rdma_connection

We should call put_recvmsg() before smb_direct_disconnect_rdma_connection()
in order to call it before waking up the callers.

In all error cases we should call smb_direct_disconnect_rdma_connection()
in order to avoid stale connections.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: 0626e66 ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: metze-samba

fs/smb/server/transport_rdma.c

@@ -521,13 +521,13 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 	t = recvmsg->transport;
 
 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) {
+		put_recvmsg(t, recvmsg);
 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
 			pr_err("Recv error. status='%s (%d)' opcode=%d\n",
 			       ib_wc_status_msg(wc->status), wc->status,
 			       wc->opcode);
 			smb_direct_disconnect_rdma_connection(t);
 		}
-		put_recvmsg(t, recvmsg);
 		return;
 	}
 
@@ -542,14 +542,15 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 	case SMB_DIRECT_MSG_NEGOTIATE_REQ:
 		if (wc->byte_len < sizeof(struct smb_direct_negotiate_req)) {
 			put_recvmsg(t, recvmsg);
+			smb_direct_disconnect_rdma_connection(t);
 			return;
 		}
 		t->negotiation_requested = true;
 		t->full_packet_received = true;
 		t->status = SMB_DIRECT_CS_CONNECTED;
 		enqueue_reassembly(t, recvmsg, 0);
 		wake_up_interruptible(&t->wait_status);
-		break;
+		return;
 	case SMB_DIRECT_MSG_DATA_TRANSFER: {
 		struct smb_direct_data_transfer *data_transfer =
 			(struct smb_direct_data_transfer *)recvmsg->packet;
@@ -559,6 +560,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 		if (wc->byte_len <
 		    offsetof(struct smb_direct_data_transfer, padding)) {
 			put_recvmsg(t, recvmsg);
+			smb_direct_disconnect_rdma_connection(t);
 			return;
 		}
 
@@ -567,6 +569,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 			if (wc->byte_len < sizeof(struct smb_direct_data_transfer) +
 			    (u64)data_length) {
 				put_recvmsg(t, recvmsg);
+				smb_direct_disconnect_rdma_connection(t);
 				return;
 			}
 
@@ -609,11 +612,16 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 		if (is_receive_credit_post_required(receive_credits, avail_recvmsg_count))
 			mod_delayed_work(smb_direct_wq,
 					 &t->post_recv_credits_work, 0);
-		break;
+		return;
 	}
-	default:
-		break;
 	}
+
+	/*
+	 * This is an internal error!
+	 */
+	WARN_ON_ONCE(recvmsg->type != SMB_DIRECT_MSG_DATA_TRANSFER);
+	put_recvmsg(t, recvmsg);
+	smb_direct_disconnect_rdma_connection(t);
 }
 
 static int smb_direct_post_recv(struct smb_direct_transport *t,