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=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 B9FBFC3A589 for ; Tue, 20 Aug 2019 13:48:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80EE822DA9 for ; Tue, 20 Aug 2019 13:48:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308895; bh=B/hLYc7cxxyJ07aBCg1qJhDQzflRg5gX4K4s5PkaqLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=diyZyyUv1OHuTXFdklClql/VqKENnRJ9P2dXdv1VsCG1lBrrITnRjpVPG9mnGIKkf TBedPpaDg9WfmIlaYCnsgRpy+1hXhRhqDPKTcszfnhaeeXwm8FC+4nhA3YLCmBS9Y8 BAvUhMbs0FeMDUc2CA1qz+2337aRBnV+TTLmiGmM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730189AbfHTNsO (ORCPT ); Tue, 20 Aug 2019 09:48:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:35300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728248AbfHTNkg (ORCPT ); Tue, 20 Aug 2019 09:40:36 -0400 Received: from sasha-vm.mshome.net (unknown [12.236.144.82]) (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 1FEAE230F2; Tue, 20 Aug 2019 13:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308435; bh=B/hLYc7cxxyJ07aBCg1qJhDQzflRg5gX4K4s5PkaqLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fzUqS5DmbY3mSkYW32zqkfshDdDxiSpWaWtZ1SoeLxaOngchoE+SiY8eD1t7TDGnr V8rKQRtijMV5sqLrjOTT4XhhUEiR3KF4AdMZgpzbINbuiYdZqpSuTPwYAXjiSaDzuI hoNl58xwGi9vs8AvD/i1KFRtpV5ykY4Sk7wlIWWo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , Sasha Levin , linux-afs@lists.infradead.org Subject: [PATCH AUTOSEL 5.2 07/44] afs: Only update d_fsdata if different in afs_d_revalidate() Date: Tue, 20 Aug 2019 09:39:51 -0400 Message-Id: <20190820134028.10829-7-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190820134028.10829-1-sashal@kernel.org> References: <20190820134028.10829-1-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: David Howells [ Upstream commit 5dc84855b0fc7e1db182b55c5564fd539d6eff92 ] In the in-kernel afs filesystem, d_fsdata is set with the data version of the parent directory. afs_d_revalidate() will update this to the current directory version, but it shouldn't do this if it the value it read from d_fsdata is the same as no lock is held and cmpxchg() is not used. Fix the code to only change the value if it is different from the current directory version. Fixes: 260a980317da ("[AFS]: Add "directory write" support.") Signed-off-by: David Howells Signed-off-by: Sasha Levin --- fs/afs/dir.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 9750ac70f8ffb..b87b41721eaa8 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -1018,7 +1018,7 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) dir_version = (long)dir->status.data_version; de_version = (long)dentry->d_fsdata; if (de_version == dir_version) - goto out_valid; + goto out_valid_noupdate; dir_version = (long)dir->invalid_before; if (de_version - dir_version >= 0) @@ -1082,6 +1082,7 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) out_valid: dentry->d_fsdata = (void *)dir_version; +out_valid_noupdate: dput(parent); key_put(key); _leave(" = 1 [valid]"); -- 2.20.1