From patchwork Mon Feb 1 00:53:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12057853 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 791E1C433E0 for ; Mon, 1 Feb 2021 00:54:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C2D664E09 for ; Mon, 1 Feb 2021 00:54:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229594AbhBAAxo (ORCPT ); Sun, 31 Jan 2021 19:53:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:51228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229535AbhBAAxn (ORCPT ); Sun, 31 Jan 2021 19:53:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9E36F64E0F; Mon, 1 Feb 2021 00:53:02 +0000 (UTC) Subject: [PATCH v1] SUNRPC: Fix NFS READs that start at non-page-aligned offsets From: Chuck Lever To: linux-nfs@vger.kernel.org Cc: avian@extremenerds.net Date: Sun, 31 Jan 2021 19:53:01 -0500 Message-ID: <161214078155.1093.2334504504623797564.stgit@klimt.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Anj Duvnjak reports that the Kodi.tv NFS client is not able to read video files from a v5.10.11 Linux NFS server. The new sendpage-based TCP sendto logic was not attentive to non- zero page_base values. nfsd_splice_read() sets that field when a READ payload starts in the middle of a page. The Linux NFS client rarely emits an NFS READ that is not page- aligned. All of my testing so far has been with Linux clients, so I missed this one. Reported-by: A. Duvnjak BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211471 Fixes: 4a85a6a3320b ("SUNRPC: Handle TCP socket sends with kernel_sendpage() again") Signed-off-by: Chuck Lever --- net/sunrpc/svcsock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index c9766d07eb81..5a809c64dc7b 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1113,14 +1113,15 @@ static int svc_tcp_sendmsg(struct socket *sock, struct msghdr *msg, unsigned int offset, len, remaining; struct bio_vec *bvec; - bvec = xdr->bvec; - offset = xdr->page_base; + bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT); + offset = offset_in_page(xdr->page_base); remaining = xdr->page_len; flags = MSG_MORE | MSG_SENDPAGE_NOTLAST; while (remaining > 0) { if (remaining <= PAGE_SIZE && tail->iov_len == 0) flags = 0; - len = min(remaining, bvec->bv_len); + + len = min(remaining, bvec->bv_len - offset); ret = kernel_sendpage(sock, bvec->bv_page, bvec->bv_offset + offset, len, flags);