From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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> In-Reply-To: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> References: <1461629220-16280-1-git-send-email-jaegeuk@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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