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=-0.8 required=3.0 tests=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 6E1BDC2D0C0 for ; Thu, 19 Dec 2019 09:54:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D9D2206D8 for ; Thu, 19 Dec 2019 09:54:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726903AbfLSJyF (ORCPT ); Thu, 19 Dec 2019 04:54:05 -0500 Received: from mail-oi1-f195.google.com ([209.85.167.195]:34934 "EHLO mail-oi1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbfLSJyF (ORCPT ); Thu, 19 Dec 2019 04:54:05 -0500 Received: by mail-oi1-f195.google.com with SMTP id k4so2413134oik.2 for ; Thu, 19 Dec 2019 01:54:04 -0800 (PST) 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:cc; bh=ZUKPu+3lzNZNRX0GPct7+0OF4dHxMBRWmyHMUXjgvFU=; b=dM9Dri73SBvMSb0MX1ghwOP6xNEYF5EtDsbBpOmR1Lva+bOM7B8n9PHhi/okQdn0OP +tAolcwYNoU3Mofv2EDgwS2h55JBQwctHSUCQ3WnL5FdDGauPJRFto0A3McVO7j3tuDq AohhVrGgpKe8/Wa8bnun2nN5nUX9m0zT2fmnq+HFnXxWInBYrwSO0Fc7g4CEZz7A5CNx 8tq56bJwk0Bk7byPgvZaOKh4K2H1xJ34v9WFn8YcoZ5gMYZQgsW4pU3V8+gALe73Fvnb n4YsjOVvXoDeClqqlJfIjpXXcr8q/6un5thtHcN8Oix/YTM3+0UGQbVdXmC9ofJr2QNl YaTA== X-Gm-Message-State: APjAAAXk/Py5QLyIYaKUBRcRcJeBvTgGTRMQmLbga3R+C1oB6IoUE30c A5EkxQDLgpUjc04jGDy8lPEhbQqBe/vc+3XenkA= X-Google-Smtp-Source: APXvYqxGRCQ+HGG1eHMEhsUuHEO4jMulwydAvw7vvY4zmIqXYi1z525a9XEwSsmQKa80af+gnHaisBN2rlN7G8IGYk0= X-Received: by 2002:a05:6808:8ec:: with SMTP id d12mr1679787oic.131.1576749244150; Thu, 19 Dec 2019 01:54:04 -0800 (PST) MIME-Version: 1.0 References: <20191216062806.112361-1-yuchao0@huawei.com> In-Reply-To: <20191216062806.112361-1-yuchao0@huawei.com> From: Geert Uytterhoeven Date: Thu, 19 Dec 2019 10:53:52 +0100 Message-ID: Subject: Re: [RFC PATCH v5] f2fs: support data compression To: Chao Yu Cc: Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net, Linux Kernel Mailing List , Chao Yu Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > + 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 -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds