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=-2.2 required=3.0 tests=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 A8896C2D0D2 for ; Mon, 23 Dec 2019 03:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82C4C206D3 for ; Mon, 23 Dec 2019 03:36:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726645AbfLWDgz (ORCPT ); Sun, 22 Dec 2019 22:36:55 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:39490 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726539AbfLWDgy (ORCPT ); Sun, 22 Dec 2019 22:36:54 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 9596178A61233CC983FF; Mon, 23 Dec 2019 11:36:52 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server (TLS) id 14.3.439.0; Mon, 23 Dec 2019 11:36:50 +0800 Subject: Re: [RFC PATCH v5] f2fs: support data compression To: Geert Uytterhoeven CC: Jaegeuk Kim , , Linux Kernel Mailing List , Chao Yu References: <20191216062806.112361-1-yuchao0@huawei.com> From: Chao Yu Message-ID: Date: Mon, 23 Dec 2019 11:36:51 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/12/19 17:53, Geert Uytterhoeven wrote: > On Mon, Dec 16, 2019 at 7:29 AM Chao Yu wrote: >> This patch tries to support compression in f2fs. > >> +static int f2fs_write_raw_pages(struct compress_ctx *cc, >> + int *submitted, >> + struct writeback_control *wbc, >> + enum iostat_type io_type, >> + bool compressed) >> +{ >> + int i, _submitted; >> + int ret, err = 0; >> + >> + for (i = 0; i < cc->cluster_size; i++) { >> + if (!cc->rpages[i]) >> + continue; >> +retry_write: >> + BUG_ON(!PageLocked(cc->rpages[i])); >> + >> + ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted, >> + NULL, NULL, wbc, io_type); >> + if (ret) { >> + if (ret == AOP_WRITEPAGE_ACTIVATE) { >> + unlock_page(cc->rpages[i]); >> + ret = 0; >> + } else if (ret == -EAGAIN) { >> + ret = 0; >> + cond_resched(); >> + congestion_wait(BLK_RW_ASYNC, HZ/50); > > On some platforms, HZ can be less than 50. > What happens if congestion_wait() is called with a zero timeout? Thanks for the report, will fix in a separated patch. Thanks, > >> + lock_page(cc->rpages[i]); >> + clear_page_dirty_for_io(cc->rpages[i]); >> + goto retry_write; >> + } >> + err = ret; >> + goto out_fail; >> + } >> + >> + *submitted += _submitted; >> + } >> + return 0; >> + >> +out_fail: >> + /* TODO: revoke partially updated block addresses */ >> + BUG_ON(compressed); >> + >> + for (++i; i < cc->cluster_size; i++) { >> + if (!cc->rpages[i]) >> + continue; >> + redirty_page_for_writepage(wbc, cc->rpages[i]); >> + unlock_page(cc->rpages[i]); >> + } >> + return err; >> +} > > Gr{oetje,eeting}s, > > Geert >