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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 96561C76191 for ; Fri, 26 Jul 2019 13:59:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 661BA22CE9 for ; Fri, 26 Jul 2019 13:59:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564149554; bh=2NCJjFBUvqETWR5SVhe2n+PWH56cjMvwqLhVgy30Vuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LQQe9Z5qq2rw+YRT8SGZ/1nG1MI9rQFNKup4MS3tLs0jaIgWOv2nOKY4N+OjtCpad q8P24wPQ4s74WuZ+P+l3qwM5wquth5Cm/XqsVSbK9ZZLpl1GccA+qRMcLF8b1HPqsX /DLa0aDA4X9AMW/Fc54F4zJQ69j69PhEHR/ggMwQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387488AbfGZNkd (ORCPT ); Fri, 26 Jul 2019 09:40:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:46614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727710AbfGZNkb (ORCPT ); Fri, 26 Jul 2019 09:40:31 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 08AC522CBF; Fri, 26 Jul 2019 13:40:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148430; bh=2NCJjFBUvqETWR5SVhe2n+PWH56cjMvwqLhVgy30Vuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QaeMwGb+LrlvTNZ9ff8z7GrzHyIadNvnZKz3K7kLdMBCwmVtVy2sNF/FmN72YUCXd K6G031Sec+gmw1SMDmtG30LXCTi7OjJxGpToj1U7nLRGWRi8eUhAYZcwHAtW6Gp6XA HmASsthGofrr8sSKQrj8U9y5rSZgj1FcMfz++PkM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrea Parri , "Paul E. McKenney" , Peter Zijlstra , "Yan, Zheng" , Ilya Dryomov , Sasha Levin , ceph-devel@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 33/85] ceph: fix improper use of smp_mb__before_atomic() Date: Fri, 26 Jul 2019 09:38:43 -0400 Message-Id: <20190726133936.11177-33-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726133936.11177-1-sashal@kernel.org> References: <20190726133936.11177-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrea Parri [ Upstream commit 749607731e26dfb2558118038c40e9c0c80d23b5 ] This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic64_set() primitive. Replace the barrier with an smp_mb(). Fixes: fdd4e15838e59 ("ceph: rework dcache readdir") Reported-by: "Paul E. McKenney" Reported-by: Peter Zijlstra Signed-off-by: Andrea Parri Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/super.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 5f27e1f7f2d6..172ce582b995 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -544,7 +544,12 @@ static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci, long long release_count, long long ordered_count) { - smp_mb__before_atomic(); + /* + * Makes sure operations that setup readdir cache (update page + * cache and i_size) are strongly ordered w.r.t. the following + * atomic64_set() operations. + */ + smp_mb(); atomic64_set(&ci->i_complete_seq[0], release_count); atomic64_set(&ci->i_complete_seq[1], ordered_count); } -- 2.20.1