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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 CE6B8C433ED for ; Thu, 13 May 2021 14:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A16BD6142C for ; Thu, 13 May 2021 14:16:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234301AbhEMORM (ORCPT ); Thu, 13 May 2021 10:17:12 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:44976 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S234249AbhEMORK (ORCPT ); Thu, 13 May 2021 10:17:10 -0400 Received: from cwcc.thunk.org (pool-72-74-133-215.bstnma.fios.verizon.net [72.74.133.215]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 14DEFVOa009307 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 May 2021 10:15:32 -0400 Received: by cwcc.thunk.org (Postfix, from userid 15806) id 9B67515C3B1D; Thu, 13 May 2021 10:15:31 -0400 (EDT) Date: Thu, 13 May 2021 10:15:31 -0400 From: "Theodore Ts'o" To: Changheun Lee Cc: alex_y_xu@yahoo.ca, axboe@kernel.dk, bgoncalv@redhat.com, bvanassche@acm.org, dm-crypt@saout.de, hch@lst.de, jaegeuk@kernel.org, linux-block@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, ming.lei@redhat.com, yi.zhang@redhat.com Subject: Re: regression: data corruption with ext4 on LUKS on nvme with torvalds master Message-ID: References: <20210513094222.17635-1-nanich.lee@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210513094222.17635-1-nanich.lee@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, May 13, 2021 at 06:42:22PM +0900, Changheun Lee wrote: > > Problem might be casued by exhausting of memory. And memory exhausting > would be caused by setting of small bio_max_size. Actually it was not > reproduced in my VM environment at first. But, I reproduced same problem > when bio_max_size is set with 8KB forced. Too many bio allocation would > be occurred by setting of 8KB bio_max_size. Hmm... I'm not sure how to align your diagnosis with the symptoms in the bug report. If we were limited by memory, that should slow down the I/O, but we should still be making forward progress, no? And a forced reboot should not result in data corruption, unless maybe there was a missing check for a failed memory allocation, causing data to be written to the wrong location, a missing error check leading to the block or file system layer not noticing that a write had failed (although again, memory exhaustion should not lead to failed writes; it might slow us down, sure, but if writes are being failed, something is Badly Going Wrong --- things like writes to the swap device or writes by the page cleaner must succeed, or else Things Would Go Bad In A Hurry). - Ted