From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45930 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933648AbdJJT7J (ORCPT ); Tue, 10 Oct 2017 15:59:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Olaf Hering , "K. Y. Srinivasan" Subject: [PATCH 4.9 082/105] Drivers: hv: fcopy: restore correct transfer length Date: Tue, 10 Oct 2017 21:50:53 +0200 Message-Id: <20171010192546.381145539@linuxfoundation.org> In-Reply-To: <20171010192533.717049376@linuxfoundation.org> References: <20171010192533.717049376@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Olaf Hering commit 549e658a0919e355a2b2144dc380b3729bef7f3e upstream. Till recently the expected length of bytes read by the daemon did depend on the context. It was either hv_start_fcopy or hv_do_fcopy. The daemon had a buffer size of two pages, which was much larger than needed. Now the expected length of bytes read by the daemon changed slightly. For START_FILE_COPY it is still the size of hv_start_fcopy. But for WRITE_TO_FILE and the other operations it is as large as the buffer that arrived via vmbus. In case of WRITE_TO_FILE that is slightly larger than a struct hv_do_fcopy. Since the buffer in the daemon was still larger everything was fine. Currently, the daemon reads only what is actually needed. The new buffer layout is as large as a struct hv_do_fcopy, for the WRITE_TO_FILE operation. Since the kernel expects a slightly larger size, hvt_op_read will return -EINVAL because the daemon will read slightly less than expected. Address this by restoring the expected buffer size in case of WRITE_TO_FILE. Fixes: 'c7e490fc23eb ("Drivers: hv: fcopy: convert to hv_utils_transport")' Fixes: '3f2baa8a7d2e ("Tools: hv: update buffer handling in hv_fcopy_daemon")' Signed-off-by: Olaf Hering Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_fcopy.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -161,6 +161,10 @@ static void fcopy_send_data(struct work_ out_src = smsg_out; break; + case WRITE_TO_FILE: + out_src = fcopy_transaction.fcopy_msg; + out_len = sizeof(struct hv_do_fcopy); + break; default: out_src = fcopy_transaction.fcopy_msg; out_len = fcopy_transaction.recv_len;