From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Mahoney , Jan Kara Subject: [PATCH 3.4 29/43] reiserfs: fix race in readdir Date: Sun, 4 May 2014 11:42:23 -0400 Message-Id: <20140504154228.222208999@linuxfoundation.org> In-Reply-To: <20140504154224.211508175@linuxfoundation.org> References: <20140504154224.211508175@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Mahoney commit 01d8885785a60ae8f4c37b0ed75bdc96d0fc6a44 upstream. jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2) The -ENOENT is due to readdir calling dir_emit on the same entry twice. If the dir_emit callback sleeps and the tree is changed underneath us, we won't be able to trust deh_offset(deh) anymore. We need to save next_pos before we might sleep so we can find the next entry. Signed-off-by: Jeff Mahoney Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/reiserfs/dir.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/reiserfs/dir.c +++ b/fs/reiserfs/dir.c @@ -128,6 +128,7 @@ int reiserfs_readdir_dentry(struct dentr char *d_name; off_t d_off; ino_t d_ino; + loff_t cur_pos = deh_offset(deh); if (!de_visible(deh)) /* it is hidden entry */ @@ -200,8 +201,9 @@ int reiserfs_readdir_dentry(struct dentr if (local_buf != small_buf) { kfree(local_buf); } - // next entry should be looked for with such offset - next_pos = deh_offset(deh) + 1; + + /* deh_offset(deh) may be invalid now. */ + next_pos = cur_pos + 1; if (item_moved(&tmp_ih, &path_to_entry)) { goto research;