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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 394FFC3524E for ; Mon, 3 Feb 2020 08:29:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F88020658 for ; Mon, 3 Feb 2020 08:29:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="R5Uub/j2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727615AbgBCI3p (ORCPT ); Mon, 3 Feb 2020 03:29:45 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:40994 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727395AbgBCI3o (ORCPT ); Mon, 3 Feb 2020 03:29:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=UzHY2//8nge+6AVz84GBD+Hiv1MkHhsGePN/RRAL/cs=; b=R5Uub/j2Jo28TKhRreGG9CUlb L4WkOC7oIXbvx8zk1UOuQf7fLPmBgfXC/qq3bYoGjjZdWMuAWNbxKnOMPGohuXnLdEczq0aLhSKLX EvjwaCM91D24YH0KJyR9qrfYZ0vIcGRVi8fQegDE0zy2p9UGPX0FNuhV+t8jBZhPjBWvYKS1fptB4 BBcTHVkMBOSQZEajpYRQOGYGiFF+j3WedTdsCrKTdtfdogVif4+m84FGw9jQ1DBxubexp1IFDF0/E fTF37QXlaWCbgMQLk+RG0WZA+rqzIRpMGDHt4GVqAo9Y0Ik4XHkaoBcZT7+2ZAHV+QL+liHBTVMxZ VETRHgVeA==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iyX6x-00078v-2d; Mon, 03 Feb 2020 08:29:39 +0000 Date: Mon, 3 Feb 2020 00:29:39 -0800 From: Christoph Hellwig To: Johannes Thumshirn Cc: "dsterba@suse.cz" , Christoph Hellwig , David Sterba , Nikolay Borisov , "linux-btrfs @ vger . kernel . org" Subject: Re: [PATCH v3 0/5] btrfs: remove buffer heads form superblock handling Message-ID: <20200203082939.GA25604@infradead.org> References: <20200127155931.10818-1-johannes.thumshirn@wdc.com> <20200129142526.GE3929@twin.jikos.cz> <20200130121530.GO3929@twin.jikos.cz> <20200130133921.GA21841@infradead.org> <20200130161606.GV3929@twin.jikos.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, Jan 31, 2020 at 01:43:19PM +0000, Johannes Thumshirn wrote: > > I have a local version now, where btrfs_read_dev_one_super() uses > read_cache_page_gfp() and btrfs_scratch_superblocks() uses > write_one_page() offloading all the I/O to the pagecache. So far this > works as expected. > > Now when I started converting write_dev_supers() and friends I wasn't > sure if I can/should mix up read_cache_page_gfp() and submit_bio_wait(). > I could also convert it to write_one_page() but this way we would loose > integrity checking for the super block. > > Any advice? You can mix it, although it needs some big fat comments explaining what is going on there to the reader.