From patchwork Thu Jul 11 18:41:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 11040689 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DF71B14DB for ; Thu, 11 Jul 2019 18:41:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D46DD28846 for ; Thu, 11 Jul 2019 18:41:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C870128905; Thu, 11 Jul 2019 18:41:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7672028846 for ; Thu, 11 Jul 2019 18:41:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730256AbfGKSlo (ORCPT ); Thu, 11 Jul 2019 14:41:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:47794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730246AbfGKSlo (ORCPT ); Thu, 11 Jul 2019 14:41:44 -0400 Received: from tleilax.poochiereds.net (cpe-71-70-156-158.nc.res.rr.com [71.70.156.158]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DE54A2166E; Thu, 11 Jul 2019 18:41:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562870503; bh=E0XgnaRjFv6HDkww4jzqZoNYTr7VDJpb2nWWDEcSvvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nz19vKWQ4RQjEeKWBa2GPrTfA3bhAdHFfdcNOCJv0Xun6FTwfND0BPgl/bT78X+IT aruD4J2tXKjiidWTjr1doCctgKqbXmaHV0/ONV/ffmSw3Kh00rO2d+tUv1PqPlc2JT QKIUpQXaMc7ife6BfjddYM2UnXlb7Zs6nY6BQkRM= From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: zyan@redhat.com, idryomov@gmail.com, sage@redhat.com, lhenriques@suse.com Subject: [PATCH v2 4/5] ceph: lock page before checking Uptodate flag Date: Thu, 11 Jul 2019 14:41:35 -0400 Message-Id: <20190711184136.19779-5-jlayton@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190711184136.19779-1-jlayton@kernel.org> References: <20190711184136.19779-1-jlayton@kernel.org> MIME-Version: 1.0 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We could end up racing with a call to set or clear the Uptodate flag prior to taking the page lock. Use find_lock_page instead to have it return a locked page and unlock it before releasing it if it's not Uptodate. Signed-off-by: Jeff Layton --- fs/ceph/addr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 4606da82da6f..83b1f6dccab8 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1715,12 +1715,12 @@ int ceph_uninline_data(struct inode *inode, struct page *provided_page) WARN_ON(!PageUptodate(page)); } else if (ceph_caps_issued(ci) & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) { - page = find_get_page(inode->i_mapping, 0); + page = find_lock_page(inode->i_mapping, 0); if (page) { if (PageUptodate(page)) { from_pagecache = true; - lock_page(page); } else { + unlock_page(page); put_page(page); page = NULL; }