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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EB32BC433FF for ; Mon, 5 Aug 2019 13:05:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AE54216F4 for ; Mon, 5 Aug 2019 13:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565010302; bh=iOD5e/7hmLfDGVKf/IPE7v43E5I8yZYwjWofb09Bq5M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HW7XfwLirRyymS6/w5caEbbJ4y3TqCXMVYLZnzeewKuFb/t6wpT5gti8gEPjm+7o6 h0oVKp7kY3e/ee5qEanXMjV/ST2GL4dbFA5VQxYt/7Efe9s/xEgjVo1GMXu498Xd4W biYA+M1LHpCWsgDtWA1V26LmW2W9ll52+zhrGBts= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729205AbfHENFB (ORCPT ); Mon, 5 Aug 2019 09:05:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:40762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729171AbfHENEz (ORCPT ); Mon, 5 Aug 2019 09:04:55 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 13CA5214C6; Mon, 5 Aug 2019 13:04:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565010294; bh=iOD5e/7hmLfDGVKf/IPE7v43E5I8yZYwjWofb09Bq5M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F8oMmSIUTCIE1uC/gcxa7D/oIkWOBPQI0nnTF6EFBwiohYkU9jYVlxVvaiJ3RNs1h 1sO/DZNi8m/wWhoFMgSlUz7wbR4bH1oB9up5CXFdz5BDMdKc8IrkkNeiHWDfuqS0vx B/GNXSDFO+bmg+tNG/BGp8f8SFtpFfSPsZBo2sPI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Paul E. McKenney" , Peter Zijlstra , Andrea Parri , "Yan, Zheng" , Ilya Dryomov , Sasha Levin Subject: [PATCH 4.9 11/42] ceph: fix improper use of smp_mb__before_atomic() Date: Mon, 5 Aug 2019 15:02:37 +0200 Message-Id: <20190805124926.168358583@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190805124924.788666484@linuxfoundation.org> References: <20190805124924.788666484@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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 622d5dd9f6169..9bd0d928057b7 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