Received: by 2002:a05:7412:8d06:b0:f9:332d:97f1 with SMTP id bj6csp11723rdb; Mon, 18 Dec 2023 07:39:21 -0800 (PST) X-Google-Smtp-Source: AGHT+IGWXSH/7bYVx8LXGMBMdaW2cf2tGeq1Nkt0LBVFFoiy2AeM7siGHtvj5gfLS1hkdWxfKTla X-Received: by 2002:a17:902:bc4c:b0:1d3:aa36:3b7 with SMTP id t12-20020a170902bc4c00b001d3aa3603b7mr2955845plz.18.1702913960694; Mon, 18 Dec 2023 07:39:20 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1702913960; cv=none; d=google.com; s=arc-20160816; b=i+pFIPs+KzzXAU3iTZlSShSu/ywp2bitizvWLWnqJ3XWp6BIsStKkuiVV7STsUDMAO miMkSWt4ZcIgMVTlNbZY3JhKju7J/fa0jw0UvHLlDjiN1HJcikHVi9atz+QIdJl/QwR1 8rIm8DLKJhXHlZYElzH0vAuHchIT4cEKcvFWqprrfrE7VDde8hBotEnc477KZofU3Kdl /m8J9chiwV1DDWixbu4OnC65HJIs7wpq4wYdXBpVJsUzDcAuAAID2cysW3zFh4J6fWIq BEnYXF2zP+3hCFvczYChRDbzxQC6opKvyqptB0hZ67x0PHOLZ+CIm4m+waPjHNArW497 dj+g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=SkcRys0g0eAUf8/FxArC7DdEKspx8sFQujh+FCrTtN4=; fh=m0HBXuwgOCKat7wyuY7vstPypqMqxNmINnjBv5+EUjU=; b=sk59IaP+/Ekr4WaFnviEEaqqm/82VANJswl6xMLlzbIi+PqyR2rX0uYxNls7UZbpQh ByGinx9q087jxR9wZ086mOH7K3NzK55SfSSdPQQ5JY646rxGyoZG90BnE+Ztbp2ddoFC o/E81lLwUR6uTfCNLQzyont90ADX40OSUldcFniugbvc8/PYl3ZgbnrFC8RzUIfZ8dAH +q25iaWIsKL3jyi6/dFEDNK8U3otobiaCbdHJzjFhdBEr6KwJTaGiY/Hi/WT9fehFro2 ZarLEbqeBkApMq9kP4GD3T6Yr/lSTQayJk3vOyqVJHOWVNcAwe580vYhXXa6/fZvx5AL s+8Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b=wv7lyBIR; spf=pass (google.com: domain of linux-kernel+bounces-3945-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) smtp.mailfrom="linux-kernel+bounces-3945-linux.lists.archive=gmail.com@vger.kernel.org" Return-Path: Received: from sy.mirrors.kernel.org (sy.mirrors.kernel.org. [147.75.48.161]) by mx.google.com with ESMTPS id ju9-20020a170903428900b001d0a0ee28e0si427231plb.288.2023.12.18.07.39.20 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 07:39:20 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-3945-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b=wv7lyBIR; spf=pass (google.com: domain of linux-kernel+bounces-3945-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) smtp.mailfrom="linux-kernel+bounces-3945-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 0AC86B233FA for ; Mon, 18 Dec 2023 15:37:16 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E14093D568; Mon, 18 Dec 2023 15:36:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="wv7lyBIR" X-Original-To: linux-kernel@vger.kernel.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 966BF4FF74; Mon, 18 Dec 2023 15:36:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=SkcRys0g0eAUf8/FxArC7DdEKspx8sFQujh+FCrTtN4=; b=wv7lyBIRNIQLwC91K/1xIPUpmW 14UXm/U10zKWL8yi3CuNad4Wvj16dy3mlQm0OVgg9NbwoDwc9qHaPbHXu2UjDhtjk2lWCXoBQfv5y YEpJvvDmZco1oWzVjD3D1Bgi4x8XaNM+D43GKOOpJzTHkDmAlPg/KuQswq8wrsi4bfjwuTjO/hdvm dUdZUwx4kWJO8dxO3K/HNOHsO1nztgCOjXKRGJ3UzIgnl6x1j4KIzYPFncrhFFqH64N2gYSfK/F7I wirO6bPgiOsKjEkwmyDnPYkuODr8U12dz5uP43SplWoRAOxukXhfL16C6CpPgTpzEr6QuMYcez9D6 2LhabeBQ==; Received: from 2a02-8389-2341-5b80-39d3-4735-9a3c-88d8.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:39d3:4735:9a3c:88d8] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1rFFf1-00BEIj-0m; Mon, 18 Dec 2023 15:36:03 +0000 From: Christoph Hellwig To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , Jan Kara , David Howells , Brian Foster , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/17] writeback: rework the loop termination condition in write_cache_pages Date: Mon, 18 Dec 2023 16:35:39 +0100 Message-Id: <20231218153553.807799-4-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231218153553.807799-1-hch@lst.de> References: <20231218153553.807799-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Rework we deal with the cleanup after the writepage call. First handle the magic AOP_WRITEPAGE_ACTIVATE separately from real error returns to get it out of the way of the actual error handling. Then merge the code to set ret for integrity vs non-integrity writeback. For non-integrity writeback the loop is terminated on the first error, so ret will never be non-zero. Then use a single block to check for non-integrity writewack to consolidate the cases where it returns for either an error or running off the end of nr_to_write. Signed-off-by: Christoph Hellwig --- mm/page-writeback.c | 62 +++++++++++++++++++++------------------------ 1 file changed, 29 insertions(+), 33 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 8e312d73475646..7ed6c2bc8dd51c 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2474,43 +2474,39 @@ int write_cache_pages(struct address_space *mapping, error = writepage(folio, wbc, data); nr = folio_nr_pages(folio); wbc->nr_to_write -= nr; - if (unlikely(error)) { - /* - * Handle errors according to the type of - * writeback. There's no need to continue for - * background writeback. Just push done_index - * past this page so media errors won't choke - * writeout for the entire file. For integrity - * writeback, we must process the entire dirty - * set regardless of errors because the fs may - * still have state to clear for each page. In - * that case we continue processing and return - * the first error. - */ - if (error == AOP_WRITEPAGE_ACTIVATE) { - folio_unlock(folio); - error = 0; - } else if (wbc->sync_mode != WB_SYNC_ALL) { - ret = error; - done_index = folio->index + nr; - done = 1; - break; - } - if (!ret) - ret = error; + + /* + * Handle the legacy AOP_WRITEPAGE_ACTIVATE magic return + * value. Eventually all instances should just unlock + * the folio themselves and return 0; + */ + if (error == AOP_WRITEPAGE_ACTIVATE) { + folio_unlock(folio); + error = 0; } /* - * We stop writing back only if we are not doing - * integrity sync. In case of integrity sync we have to - * keep going until we have written all the pages - * we tagged for writeback prior to entering this loop. + * For integrity sync we have to keep going until we + * have written all the folios we tagged for writeback + * prior to entering this loop, even if we run past + * wbc->nr_to_write or encounter errors. This is + * because the file system may still have state to clear + * for each folio. We'll eventually return the first + * error encountered. + * + * For background writeback just push done_index past + * this folio so that we can just restart where we left + * off and media errors won't choke writeout for the + * entire file. */ - done_index = folio->index + nr; - if (wbc->nr_to_write <= 0 && - wbc->sync_mode == WB_SYNC_NONE) { - done = 1; - break; + if (error && !ret) + ret = error; + if (wbc->sync_mode == WB_SYNC_NONE) { + if (ret || wbc->nr_to_write <= 0) { + done_index = folio->index + nr; + done = 1; + break; + } } } folio_batch_release(&fbatch); -- 2.39.2