From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35746C433EF for ; Tue, 19 Apr 2022 18:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344083AbiDSSEq (ORCPT ); Tue, 19 Apr 2022 14:04:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238961AbiDSSEo (ORCPT ); Tue, 19 Apr 2022 14:04:44 -0400 Received: from nibbler.cm4all.net (nibbler.cm4all.net [IPv6:2001:8d8:970:e500:82:165:145:151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1FD23A192 for ; Tue, 19 Apr 2022 11:02:00 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by nibbler.cm4all.net (Postfix) with ESMTP id 3ED21C00A1 for ; Tue, 19 Apr 2022 20:01:59 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at nibbler.cm4all.net Received: from nibbler.cm4all.net ([127.0.0.1]) by localhost (nibbler.cm4all.net [127.0.0.1]) (amavisd-new, port 10024) with LMTP id hPWNnCV-JEvv for ; Tue, 19 Apr 2022 20:01:52 +0200 (CEST) Received: from zero.intern.cm-ag (zero.intern.cm-ag [172.30.16.10]) by nibbler.cm4all.net (Postfix) with SMTP id 218B6C00D5 for ; Tue, 19 Apr 2022 20:01:52 +0200 (CEST) Received: (qmail 2504 invoked from network); 19 Apr 2022 23:51:54 +0200 Received: from unknown (HELO rabbit.intern.cm-ag) (172.30.3.1) by zero.intern.cm-ag with SMTP; 19 Apr 2022 23:51:54 +0200 Received: by rabbit.intern.cm-ag (Postfix, from userid 1023) id E6D21460F1C; Tue, 19 Apr 2022 20:01:51 +0200 (CEST) Date: Tue, 19 Apr 2022 20:01:51 +0200 From: Max Kellermann To: David Howells Cc: Max Kellermann , linux-cachefs@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: fscache corruption in Linux 5.17? Message-ID: References: <507518.1650383808@warthog.procyon.org.uk> <509961.1650386569@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <509961.1650386569@warthog.procyon.org.uk> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2022/04/19 18:42, David Howells wrote: > Could the file have been modified by a third party? According to our support tickets, the customers used WordPress's built-in updater, which resulted in corrupt PHP sources. We have configured stickiness in the load balancer; HTTP requests to one website always go through the same web server. Which implies that the same web server that saw the corrupt files was the very same one that wrote the new file contents. This part surprises me, because writing a page to the NFS server should update (or flush/invalidate) the old cache page. It would be easy for a *different* NFS client to miss out on updated file contents, but this is not what happened. On 2022/04/19 18:47, David Howells wrote: > Do the NFS servers change the files that are being served - or is it > just WordPress pushing the changes to the NFS servers for the web > servers to then export? I'm not sure if I understand this question correctly. The NFS server (a NetApp, btw.) sees the new file contents correctly; all other web servers also see non-corrupt new files. Only the one web server which performed the update saw broken files. Max