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 8A5F3C3A59E for ; Tue, 20 Aug 2019 13:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43E01230F2 for ; Tue, 20 Aug 2019 13:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308776; bh=U1wmmqt8IFCCBee96fUQLklIQ9/Yo6GEXftgBp6Hmrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UwcAth09ylOW3OK919tTE8I/6LX0Snbiir+DyEhu0JxGTcHQmc6Wwdr5/JaT6LUNu fPDKMpCl+BUgPjKo4/u6yuJO1GED4/313xsWwjhSzaFy8M+RJbN0sbxDHtqIZ2bUaW hFgJuaYJAK0fKjbBBM5+KUwJMTiri7AcePWJ7oOs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730071AbfHTNqP (ORCPT ); Tue, 20 Aug 2019 09:46:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:37608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730576AbfHTNmU (ORCPT ); Tue, 20 Aug 2019 09:42:20 -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 CA1F82332B; Tue, 20 Aug 2019 13:42:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308539; bh=U1wmmqt8IFCCBee96fUQLklIQ9/Yo6GEXftgBp6Hmrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VDbCA0OHHzSjVMSCVxjueD0FjeJ1oRRwRhEl6v6DUOQg+ZJVBajG06xh3H3vZJ1+7 Io0UCQmJHm4Hu97vduBJxQng1RaWjKy0RguzfPPeQuYcg6xyHRZroX41vX1lj4uagh ekKaLy0acvmwaWcLl9OM+vXmgff7GYBNzhBK/MGo= 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 4.19 06/27] afs: Only update d_fsdata if different in afs_d_revalidate() Date: Tue, 20 Aug 2019 09:41:52 -0400 Message-Id: <20190820134213.11279-6-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190820134213.11279-1-sashal@kernel.org> References: <20190820134213.11279-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 855bf2b79fed4..54e7f6f1405e2 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -937,7 +937,7 @@ 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) @@ -1001,6 +1001,7 @@ 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