From patchwork Sat Dec 20 18:02:43 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "J. Bruce Fields" X-Patchwork-Id: 5523071 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B518F9F326 for ; Sat, 20 Dec 2014 18:02:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B2BF120158 for ; Sat, 20 Dec 2014 18:02:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78EEB20109 for ; Sat, 20 Dec 2014 18:02:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751083AbaLTSCp (ORCPT ); Sat, 20 Dec 2014 13:02:45 -0500 Received: from fieldses.org ([174.143.236.118]:55864 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750785AbaLTSCo (ORCPT ); Sat, 20 Dec 2014 13:02:44 -0500 Received: from bfields by fieldses.org with local (Exim 4.76) (envelope-from ) id 1Y2OMV-0002kA-8a; Sat, 20 Dec 2014 13:02:43 -0500 Date: Sat, 20 Dec 2014 13:02:43 -0500 From: "J. Bruce Fields" To: Holger =?utf-8?Q?Hoffst=C3=A4tte?= Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: 3.18.1: broken directory with one file too many Message-ID: <20141220180243.GA10273@fieldses.org> References: <20141217212159.GA11517@fieldses.org> <5492C710.20104@googlemail.com> <20141218144856.GA18179@fieldses.org> <20141218151914.GB18179@fieldses.org> <20141218163254.GF18179@fieldses.org> <549303FC.9090604@googlemail.com> <20141218170653.GG18179@fieldses.org> <54932EA5.9090803@googlemail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <54932EA5.9090803@googlemail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Thu, Dec 18, 2014 at 08:44:37PM +0100, Holger Hoffstätte wrote: > On 12/18/14 18:06, J. Bruce Fields wrote: > > Whoops, now I see, the server-side trace has the same problem, I > > just overlooked it the first time. > > Excellent, so we know it's the server's fault. Really would have been odd to not have it in the server trace. > > >> ..in order to rule out a mistake on my part with the two separate > >> runs (which prevents correlated analysis) I was just about to boot > >> the server back into 3.18.1 and re-run both client- and server-side > >> traces simultaneously. However I have to head out for a bit first; > >> will post that later today. > > > > So this might still be interesting, but it's not a high priority. > > Then I guess I'll better keep my feet still and don't muddle the waters further, looks like you found what you need. If you still need it just holler. > > Let me know if there's anything I can do to help/patch/test! Gah. Does this fix it? A struct xdr_stream at a page boundary might point to the end of one page or the beginning of the next, and I'm guessing xdr_truncate_encode wasn't prepared to handle the former. This happens if the readdir entry that would have exceeded the client's dircount/maxcount limit would have ended exactly on a 4k page boundary, and inspection of the trace shows you're hitting exactly that case. If this does the job then I'll go figure out how to make this logic less ugly.... --b. Reported-by: Holger Hoffstätte Tested-by: Holger Hoffstätte --- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 1cb61242e55e..32910b91d17c 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -630,6 +630,9 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) new = buf->page_base + buf->page_len; old = new + fraglen; + /* XXX: HACK: */ + if (xdr->p == page_address(*xdr->page_ptr) + PAGE_SIZE) + xdr->page_ptr++; xdr->page_ptr -= (old >> PAGE_SHIFT) - (new >> PAGE_SHIFT); if (buf->page_len) {