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=-3.9 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 E2428C388F9 for ; Fri, 23 Oct 2020 11:42:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8587120EDD for ; Fri, 23 Oct 2020 11:42:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ACJo1cAn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463151AbgJWLmW (ORCPT ); Fri, 23 Oct 2020 07:42:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S463147AbgJWLmW (ORCPT ); Fri, 23 Oct 2020 07:42:22 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83323C0613CE; Fri, 23 Oct 2020 04:42:22 -0700 (PDT) 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=uTBzimS1PCb6rk5CYfmm7DQ57ZumL5IF6N2uuwCT5ic=; b=ACJo1cAnkf3SCtOXvhzF84HPAz utZFVfmrmNmBVfyFa5t0dItqVsR7LlM9a/jTwu2II5s5V7yF3kAfVMAnMzrXyZDJpdWcEwVJSnBdA ssO+4GIuRRj3bJhia6MZuAmiwlqfgDAZwC+arcGcmvM62SC4BkH/APIgbr+WE9JUWbkEsxQJv1T+8 URB45+a6Ia7ysOI4DPNhoQMYW4TeQKE/LaC/YAFY5RH5zcgq+ifmOcQ6rd+lmpRFWMkpzlB1/MrUx w1PAwnEZ8ryBA9uzRY/Ptw2NcZNt8qJY6m1u4wwhuG9ZxAeJpjMOjMJrrw6GfqYiffp3/XudIOj1F F69t2U5g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVvSe-0007Yd-Ua; Fri, 23 Oct 2020 11:42:21 +0000 Date: Fri, 23 Oct 2020 12:42:20 +0100 From: Matthew Wilcox To: Hannes Reinecke Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] synchronous readpage for buffer_heads Message-ID: <20201023114220.GY20115@casper.infradead.org> References: <20201022152256.GU20115@casper.infradead.org> <25528b1a-7434-62cb-705a-7269d050bbc1@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <25528b1a-7434-62cb-705a-7269d050bbc1@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Archived-At: List-Archive: List-Post: On Fri, Oct 23, 2020 at 08:22:07AM +0200, Hannes Reinecke wrote: > On 10/22/20 5:22 PM, Matthew Wilcox wrote: > Hmm. You are aware, of course, that hch et al are working on replacing bhs > with iomap, right? $ git shortlog --author=Wilcox origin/master -- fs/iomap |head -1 Matthew Wilcox (Oracle) (17): But actually, I don't see anyone working on a mass migration of filesystems from either using BHs directly or using the mpage code to using iomap. I have a summer student for next summer who I'm going to let loose on this problem, but I fear buffer_heads will be with us for a long time to come. I mean, who's going to convert reiserfs to iomap? $ git log --no-merges --since=2015-01-01 origin/master fs/reiserfs |grep -c ^comm 130 Not exactly a thriving development community. It doesn't even support fallocate. > So wouldn't it be more useful to concentrate on the iomap code, and ensure > that _that_ is working correctly? Did that one first, then did mpage_readpage(), now I've moved on to block_read_full_page(). Now I'm going to go back and redo iomap with everything I learned doing block_read_full_page(). It's going to use blk_completion.