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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 DBC11C433DB for ; Tue, 26 Jan 2021 15:11:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A096C2310E for ; Tue, 26 Jan 2021 15:11:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406079AbhAZPLL (ORCPT ); Tue, 26 Jan 2021 10:11:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406197AbhAZPJV (ORCPT ); Tue, 26 Jan 2021 10:09:21 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E93DC061A31; Tue, 26 Jan 2021 07:08:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jywVRgQb+R/8nrC6wcC0tprf9W0TUepj2A0VJnxWY7w=; b=D4n+1nPul2NOhNPZRJuwX9YBXA JCsbDOMHCHWzYej2yXoxgPSqOSFOSutcobuuWI4mrpr2gxzMUDgMRUeHaPla/101DVXo0E2AWgrYV 9qcPPaqJlzqQgs6POzLFnL8qlSEosQofGYG+V4fgpkbMBH1OXZo0s+BaoVzJ/LlxghxvO5AM8vdZC jMQpJZRfNz/zt9dVM8wPjs6RQke1S6dshAm2nT/DLTOsyf8oKb4OkCjOmzr+JzXgQOSUezIeXLnIW NfWwvWl5+8K859FC+VwnewuNACvy8w+x7rH5FySoGGAL4E4cH50i7BeSeMiPrAJHyFaG6G1Gg8GMv qIaWxJVQ==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l4PuB-005nGD-92; Tue, 26 Jan 2021 15:05:48 +0000 Date: Tue, 26 Jan 2021 15:05:19 +0000 From: Christoph Hellwig To: Ming Lei Cc: Changheun Lee , Johannes.Thumshirn@wdc.com, asml.silence@gmail.com, axboe@kernel.dk, damien.lemoal@wdc.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, osandov@fb.com, patchwork-bot@kernel.org, tj@kernel.org, tom.leiming@gmail.com, jisoo2146.oh@samsung.com, junho89.kim@samsung.com, mj0123.lee@samsung.com, seunghwan.hyun@samsung.com, sookwan7.kim@samsung.com, woosung2.lee@samsung.com, yt0928.kim@samsung.com Subject: Re: [PATCH v3 1/2] bio: limit bio max size Message-ID: <20210126150519.GA1377213@infradead.org> References: <20210126013235.28711-1-nanich.lee@samsung.com> <20210126035748.GA1071341@T590> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210126035748.GA1071341@T590> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Jan 26, 2021 at 11:57:48AM +0800, Ming Lei wrote: > > *same_page = false; > > return false; > > } > > So far we don't need bio->bi_disk or bio->bi_bdev(will be changed in > Christoph's patch) during adding page to bio, so there is null ptr > refereance risk. I've started resurrecting my old plan to always have a valid device in the bio from allocation time on. It is pretty invasive, but probably worth it. Sending out the first prep series right now, the actual changes should be ready for an RFC later this week.