smb: client: let send_done() cleanup before calling smbd_disconnect_rdma_connection()

We should call ib_dma_unmap_single() and mempool_free() before calling
smbd_disconnect_rdma_connection().

And smbd_disconnect_rdma_connection() needs to be the last function to
call as all other state might already be gone after it returns.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: metze-samba

fs/smb/client/smbdirect.c

@@ -281,18 +281,20 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 	log_rdma_send(INFO, "smbd_request 0x%p completed wc->status=%d\n",
 		request, wc->status);
 
-	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
-		log_rdma_send(ERR, "wc->status=%d wc->opcode=%d\n",
-			wc->status, wc->opcode);
-		smbd_disconnect_rdma_connection(request->info);
-	}
-
 	for (i = 0; i < request->num_sge; i++)
 		ib_dma_unmap_single(sc->ib.dev,
 			request->sge[i].addr,
 			request->sge[i].length,
 			DMA_TO_DEVICE);
 
+	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
+		log_rdma_send(ERR, "wc->status=%d wc->opcode=%d\n",
+			wc->status, wc->opcode);
+		mempool_free(request, info->request_mempool);
+		smbd_disconnect_rdma_connection(info);
+		return;
+	}
+
 	if (atomic_dec_and_test(&request->info->send_pending))
 		wake_up(&request->info->wait_send_pending);