From: Shen Feng Subject: Re: [PATCH 2/2] ext4: Make ext4_ext_find_extent fills ext_path completely Date: Fri, 13 Jun 2008 13:40:03 +0800 Message-ID: <48520833.1080802@cn.fujitsu.com> References: <484F68BE.8040203@cn.fujitsu.com> <1213309672.3698.22.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, Theodore Tso , Andrew Morton To: cmm@us.ibm.com Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:55761 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752086AbYFMFng (ORCPT ); Fri, 13 Jun 2008 01:43:36 -0400 In-Reply-To: <1213309672.3698.22.camel@localhost.localdomain> Sender: linux-ext4-owner@vger.kernel.org List-ID: Mingming Cao Wrote: > On Wed, 2008-06-11 at 13:55 +0800, Shen Feng wrote: >> When pos=0 or depth, the fields of ext4_ext_path is not >> completely filled. >> This patch also removes some unnecessary code. >> > > I added this patch to the patch queue, unless somebody disagree. > > Mingming >> Signed-off-by: Shen Feng >> --- >> fs/ext4/extents.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c >> index d4f76d7..ff609df 100644 >> --- a/fs/ext4/extents.c >> +++ b/fs/ext4/extents.c >> @@ -524,6 +524,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, >> alloc = 1; >> } >> path[0].p_hdr = eh; >> + path[0].p_bh = NULL; >> >> i = depth; >> /* walk through the tree */ >> @@ -552,12 +553,11 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, >> } >> >> path[ppos].p_depth = i; >> - path[ppos].p_hdr = eh; >> - path[ppos].p_ext = NULL; >> path[ppos].p_idx = NULL; >> >> /* find extent */ >> ext4_ext_binsearch(inode, path + ppos, block); >> + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); Today I tested the patch with bonnie++ and found that sometimes path[ppos].p_ext may be NULL. This may cause kernel oops. This is because ext4_ext_binsearch return directly when the leaf is empty. >> >> ext4_ext_show_path(inode, path); >> > > >