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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 8FF47C636C8 for ; Wed, 21 Jul 2021 02:27:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 791B761007 for ; Wed, 21 Jul 2021 02:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231262AbhGUBqf (ORCPT ); Tue, 20 Jul 2021 21:46:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229903AbhGUBqY (ORCPT ); Tue, 20 Jul 2021 21:46:24 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1923FC061574; Tue, 20 Jul 2021 19:27:02 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id a12so931870lfb.7; Tue, 20 Jul 2021 19:27:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=IMEA7XUipMCPe6h8ouCsvI5CYO5wKR/xBeSj7gVT1/8=; b=ZL2tFxwrvAaDcgkunbrl2DXK4XIAXlxgvsjOXndmxdfQ1aP/4Oi8plfR3O0VsRQxf0 Kj/IAHQTP8GgfPGfGebET4AOzmA/PyrMGb0D2skqhIVN8ZGr4m7y7dt9dY0HJ1YvZma+ Hhly9/7QgO4cZ3IYYU0q3ebArfbUXGkcF1T+IssQW79jiLOkRyIDT9kS5wSXpUKIcLOP Byz6t0ncf330RJcnL5OoaL7Om/VfFJtU0KXn+O0cZaIzkieo4LWeopnRmZMEB6jodKSn iu3uwpNM8RQPwuKkfXg1+0rjQnsUlkA4190PRkHwObJXyUh2DsNWgGSBwbB+MjlFwoBC 06vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=IMEA7XUipMCPe6h8ouCsvI5CYO5wKR/xBeSj7gVT1/8=; b=V1dzQlS+OukHfmuQd1JN2gulz7b9maORxqrBjESq3KAtOxftFSf90ZvAx9I6pJykU0 uDVvtYg8b6YPQOMtePmU1fo2skDmT/Gf9aDfVDk/n0AAZYLvBMjNuZeiZkutqDHtTekC 9HF9OIiO1GzJgGEHXmlMjnlVwChnzm9AM9UPsWJIDM0L5l7giP+kbETlDRUglktUWYm9 HUq269IfDnxTZwNa659th4/3AAgzl61VJ3V9oEbc7JJgQd38rLI9sm9D3AkTmBwvgrxu p6tJOXzX7+fKnx4qU3K+9Jvylk/7ne6KTtvoBN9p16Bo9U3IeRTyVxT8Zd5UqPIxG2F8 WoEQ== X-Gm-Message-State: AOAM530ATuAULtb5IG1Fp8mMcIXaVHp17xwgmrDG9/Ppw2zE/M0unc/P hXw8+mdWjoMu3O6nUfn7hyMqJXLFLjgg4C7v9ls= X-Google-Smtp-Source: ABdhPJy6dCrVihE64G/2FDHlAuzGdom8CulvBOLoo9EPFdwRFwalBwnjn6yQF+6SCWyYI7tIAeVjr0Y7QC+APrGtAFU= X-Received: by 2002:ac2:5482:: with SMTP id t2mr24222408lfk.135.1626834420374; Tue, 20 Jul 2021 19:27:00 -0700 (PDT) MIME-Version: 1.0 References: <20210720133554.44058-1-hsiangkao@linux.alibaba.com> <20210720204224.GK23236@magnolia> <20210721001720.GS22357@magnolia> In-Reply-To: From: =?UTF-8?Q?Andreas_Gr=C3=BCnbacher?= Date: Wed, 21 Jul 2021 04:26:47 +0200 Message-ID: Subject: Re: [PATCH v4] iomap: support tail packing inline read To: "Darrick J. Wong" , Matthew Wilcox , linux-erofs@lists.ozlabs.org, Linux FS-devel Mailing List , LKML , Christoph Hellwig , Andreas Gruenbacher Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Mi., 21. Juli 2021 um 02:33 Uhr schrieb Gao Xiang : > > And since you can only kmap one page at a time, an inline read grabs the > > first part of the data in "page one" and then we have to call > > iomap_begin a second time get a new address so that we can read the rest > > from "page two"? > > Nope, currently EROFS inline data won't cross page like this. > > But in principle, yes, I don't want to limit it to the current > EROFS or gfs2 usage. I think we could make this iomap function > more generally (I mean, I'd like to make the INLINE extent > functionity as general as possible, Nono. Can we please limit this patch what we actually need right now, and worry about extending it later? > my v1 original approach > in principle can support any inline extent in the middle of > file rather than just tail blocks, but zeroing out post-EOF > needs another iteration) and I don't see it add more code and > complexity. Thanks, Andreas 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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 2778DC636C8 for ; Wed, 21 Jul 2021 02:27:11 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B33A161178 for ; Wed, 21 Jul 2021 02:27:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B33A161178 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4GTzxT0NDpz309B for ; Wed, 21 Jul 2021 12:27:09 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=ZL2tFxwr; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2a00:1450:4864:20::12a; helo=mail-lf1-x12a.google.com; envelope-from=andreas.gruenbacher@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=ZL2tFxwr; dkim-atps=neutral Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4GTzxP1jhZz2yNK for ; Wed, 21 Jul 2021 12:27:04 +1000 (AEST) Received: by mail-lf1-x12a.google.com with SMTP id m16so895758lfg.13 for ; Tue, 20 Jul 2021 19:27:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=IMEA7XUipMCPe6h8ouCsvI5CYO5wKR/xBeSj7gVT1/8=; b=ZL2tFxwrvAaDcgkunbrl2DXK4XIAXlxgvsjOXndmxdfQ1aP/4Oi8plfR3O0VsRQxf0 Kj/IAHQTP8GgfPGfGebET4AOzmA/PyrMGb0D2skqhIVN8ZGr4m7y7dt9dY0HJ1YvZma+ Hhly9/7QgO4cZ3IYYU0q3ebArfbUXGkcF1T+IssQW79jiLOkRyIDT9kS5wSXpUKIcLOP Byz6t0ncf330RJcnL5OoaL7Om/VfFJtU0KXn+O0cZaIzkieo4LWeopnRmZMEB6jodKSn iu3uwpNM8RQPwuKkfXg1+0rjQnsUlkA4190PRkHwObJXyUh2DsNWgGSBwbB+MjlFwoBC 06vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=IMEA7XUipMCPe6h8ouCsvI5CYO5wKR/xBeSj7gVT1/8=; b=mhiKiCtM3jgiTYh/BNjsNnIyczsz+OhG+iy5yUI//vC/DEUIhNKIPpHVLLPRT8Pw/R PZxd5bSLosV8jRPdbz/ua84cMiDvzG53Df3bdSW1C8kANCiWOlMRRcpHFte2/aFfhJnE UhX1e/WzNrWss26MSVStnstaN8h+C2fGFAFphUp79gFzQCWS8Z9/AGioAgQEia2nyc4R kz0XN19PdAu7Ft5kVSVKxO1dRvVNPCOg7tsa7XHEwb67moWGYkk+TQcDA3kEOzH44Nc2 MIvZW8iOaLjddZgUZcUa+SdPndzM/m09vFggWvrw//9Q4YMORS6CyAtfTArKYpzGcfKR r2Iw== X-Gm-Message-State: AOAM531Q7qsgnqy2FgDq9ZWu9yGnf4KfRDMkJrCiyiwot01rtyPSw/V9 S6Rz30R/oFWAD4PjUE5elHJlfzAywwJDMlpof4w= X-Google-Smtp-Source: ABdhPJy6dCrVihE64G/2FDHlAuzGdom8CulvBOLoo9EPFdwRFwalBwnjn6yQF+6SCWyYI7tIAeVjr0Y7QC+APrGtAFU= X-Received: by 2002:ac2:5482:: with SMTP id t2mr24222408lfk.135.1626834420374; Tue, 20 Jul 2021 19:27:00 -0700 (PDT) MIME-Version: 1.0 References: <20210720133554.44058-1-hsiangkao@linux.alibaba.com> <20210720204224.GK23236@magnolia> <20210721001720.GS22357@magnolia> In-Reply-To: From: =?UTF-8?Q?Andreas_Gr=C3=BCnbacher?= Date: Wed, 21 Jul 2021 04:26:47 +0200 Message-ID: Subject: Re: [PATCH v4] iomap: support tail packing inline read To: "Darrick J. Wong" , Matthew Wilcox , linux-erofs@lists.ozlabs.org, Linux FS-devel Mailing List , LKML , Christoph Hellwig , Andreas Gruenbacher Content-Type: text/plain; charset="UTF-8" X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" Am Mi., 21. Juli 2021 um 02:33 Uhr schrieb Gao Xiang : > > And since you can only kmap one page at a time, an inline read grabs the > > first part of the data in "page one" and then we have to call > > iomap_begin a second time get a new address so that we can read the rest > > from "page two"? > > Nope, currently EROFS inline data won't cross page like this. > > But in principle, yes, I don't want to limit it to the current > EROFS or gfs2 usage. I think we could make this iomap function > more generally (I mean, I'd like to make the INLINE extent > functionity as general as possible, Nono. Can we please limit this patch what we actually need right now, and worry about extending it later? > my v1 original approach > in principle can support any inline extent in the middle of > file rather than just tail blocks, but zeroing out post-EOF > needs another iteration) and I don't see it add more code and > complexity. Thanks, Andreas