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 91C8BC4338F for ; Mon, 16 Aug 2021 14:16:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 756A060F11 for ; Mon, 16 Aug 2021 14:16:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230486AbhHPORD (ORCPT ); Mon, 16 Aug 2021 10:17:03 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:39880 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230094AbhHPORC (ORCPT ); Mon, 16 Aug 2021 10:17:02 -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 17GEGGSQ005364 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 16 Aug 2021 10:16:17 -0400 Received: by cwcc.thunk.org (Postfix, from userid 15806) id 83F9D15C3DB9; Mon, 16 Aug 2021 10:16:16 -0400 (EDT) Date: Mon, 16 Aug 2021 10:16:16 -0400 From: "Theodore Ts'o" To: Jan Kara Cc: yangerkun , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, yukuai3@huawei.com Subject: Re: [PATCH] ext4: stop return ENOSPC from ext4_issue_zeroout Message-ID: References: <20210804125044.2480435-1-yangerkun@huawei.com> <20210804133529.GE4578@quack2.suse.cz> <20210816100545.GF24793@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210816100545.GF24793@quack2.suse.cz> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Aug 16, 2021 at 12:05:45PM +0200, Jan Kara wrote: > > Yes, that looks indeed better. I'd note that even splitting extent may fail > due to ENOSPC on thin-provisioned storage but the chances are *much* lower. Indeed, any kind of metadata update (updating an inode atime, creating a new inode, deleting a directory entry, etc.) can fail due to ENOSPC on thin-provision storage, leading to a potentially corrupted file system since some writes will succeed, while others won't --- and that's not a scenario that's super well tested, nor is there much we can do other than remounting the file system read/only or forcing a reboot. But at least we won't throw the kernel into an infinite loop, which is what yangerkun was reporting... - Ted