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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 62C10C41514 for ; Fri, 26 Jul 2019 13:44:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 302AF22CD0 for ; Fri, 26 Jul 2019 13:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148694; bh=oBtKpssrtk9bhbLDtEqB6X5gVClL753A890gQUH2fYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zMurB0su1JYCPRKUW+++N2ugSK1kE1WACoaYqBWTcikXNEL3s3Jmc8ywKIwb2F5VD +Q3J4bNrCDk6UsLz3+AbrGFtvnYw9hvazZk38Jgs26ApLfS7CKyKZzQoL931g9sTxd HOwndQciJb+T7Cy2RSoDxFQgksXceMr1b+3Lf2lY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388453AbfGZNox (ORCPT ); Fri, 26 Jul 2019 09:44:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:53154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388424AbfGZNos (ORCPT ); Fri, 26 Jul 2019 09:44:48 -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 C8A3222CBF; Fri, 26 Jul 2019 13:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148687; bh=oBtKpssrtk9bhbLDtEqB6X5gVClL753A890gQUH2fYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vc5k0D/a+ZgrdWW30aq4epuctoRNHuHCXl0Is8A68daDilergte6sd8yFsDoF4UOl LEEZPNBGIKWxY8Mx6DWf19GfcbfpzmXc13vD80V0FML81nvdzoOL1PKQ/pYR+AHXjs txaS2o2zcb6LPiwvsgdZOalgMY3THxxveZayo8oU= 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 4.9 11/30] ceph: fix improper use of smp_mb__before_atomic() Date: Fri, 26 Jul 2019 09:44:13 -0400 Message-Id: <20190726134432.12993-11-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134432.12993-1-sashal@kernel.org> References: <20190726134432.12993-1-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 622d5dd9f616..9bd0d928057b 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -476,7 +476,12 @@ 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