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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 A518FC433E0 for ; Mon, 15 Mar 2021 15:45:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CC3964EB9 for ; Mon, 15 Mar 2021 15:45:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230221AbhCOPoe (ORCPT ); Mon, 15 Mar 2021 11:44:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:35356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229644AbhCOPoH (ORCPT ); Mon, 15 Mar 2021 11:44:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6DC0DAC17; Mon, 15 Mar 2021 15:44:06 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 4B20CDA6E2; Mon, 15 Mar 2021 16:42:05 +0100 (CET) Date: Mon, 15 Mar 2021 16:42:05 +0100 From: David Sterba To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH 0/2] btrfs: fixes for subpage which also affect read-only mount Message-ID: <20210315154205.GX7604@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: <20210315053915.62420-1-wqu@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210315053915.62420-1-wqu@suse.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, Mar 15, 2021 at 01:39:13PM +0800, Qu Wenruo wrote: > During the fstests run for btrfs subpage read-write support, generic/475 > crashes the system with a very high chance. > > It turns out the cause is also affecting btrfs subpage read-only mount > so it's worthy a quick fix. > > Also the crash call site shows a new rabbit hole of hard coded > PAGE_SHIFT in readahead. There's still a lot of PAGE_SHIFT use, not all of them are wrong but I think we'll need to do an audit and categorize the valid uses, otherwise it'll be a whack-a-mole.