From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752572AbcDZAID (ORCPT ); Mon, 25 Apr 2016 20:08:03 -0400 Received: from mail.kernel.org ([198.145.29.136]:50065 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752254AbcDZAHI (ORCPT ); Mon, 25 Apr 2016 20:07:08 -0400 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim , He YunLei Subject: [PATCH 7/7] f2fs: should check the remaining dentry bits Date: Mon, 25 Apr 2016 17:07:00 -0700 Message-Id: <1461629220-16280-7-git-send-email-jaegeuk@kernel.org> X-Mailer: git-send-email 2.6.3 In-Reply-To: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> References: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let's consider a race condition between f2fs_add_regular_entry and find_target_dentry. 1. - f2fs_add_regular_entry updated len: 24 first. | Bits: 0 0 0 1 Lens: 24 0 0 3 (name: foo) |-> - find_target_dentry checks the first bit to find "foo", then ++pointer. 2. - f2fs_add_regular_entry updates bits. |>|>| Bits: 1 1 1 1 Lens: 24 0 0 3 (name: foo) | - find_target_dentry is checking second bit, but it's len is zero, which makes the process being terminated. In this case, user can add additional dentry named "foo" accordingly. This patch enables to check the remaining bits. Signed-off-by: He YunLei Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index e90380d..aed5e6d 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -149,9 +149,9 @@ struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname, /* remain bug on condition */ if (unlikely(!de->name_len)) - d->max = -1; - - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + bit_pos++; + else + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); } de = NULL; -- 2.6.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: [PATCH 7/7] f2fs: should check the remaining dentry bits Date: Mon, 25 Apr 2016 17:07:00 -0700 Message-ID: <1461629220-16280-7-git-send-email-jaegeuk@kernel.org> References: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1auqX3-0003WE-IS for linux-f2fs-devel@lists.sourceforge.net; Tue, 26 Apr 2016 00:07:13 +0000 Received: from mail.kernel.org ([198.145.29.136]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1auqX2-00018W-Rq for linux-f2fs-devel@lists.sourceforge.net; Tue, 26 Apr 2016 00:07:13 +0000 In-Reply-To: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim Let's consider a race condition between f2fs_add_regular_entry and find_target_dentry. 1. - f2fs_add_regular_entry updated len: 24 first. | Bits: 0 0 0 1 Lens: 24 0 0 3 (name: foo) |-> - find_target_dentry checks the first bit to find "foo", then ++pointer. 2. - f2fs_add_regular_entry updates bits. |>|>| Bits: 1 1 1 1 Lens: 24 0 0 3 (name: foo) | - find_target_dentry is checking second bit, but it's len is zero, which makes the process being terminated. In this case, user can add additional dentry named "foo" accordingly. This patch enables to check the remaining bits. Signed-off-by: He YunLei Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index e90380d..aed5e6d 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -149,9 +149,9 @@ struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname, /* remain bug on condition */ if (unlikely(!de->name_len)) - d->max = -1; - - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + bit_pos++; + else + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); } de = NULL; -- 2.6.3 ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z