lkml.org 
[lkml]   [2012]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH next/mmotm] ext4: fix cache_es after merge_left
On Thu, Sep 27, 2012 at 01:31:28PM -0700, Hugh Dickins wrote:
> Kernel build with CONFIG_DEBUG_SLAB or CONFIG_SLUB_DEBUG slub_debug=FPZ
> gives me kernel BUG at fs/ext4/extents_status.c:142! That's the
> BUG_ON(es->start + es->len < es->start) in extent_status_end() called
> from ext4_es_insert_extent(). tree->cache_es has been freed and poisoned.
>
> This comes from when ext4_es_try_to_merge_left() merges es into leftward
> es1, but ext4_es_insert_extent()'s out then updates cache_es to the freed
> extent_status. ext4_es_try_to_merge_right() does not pose a problem.
>
> Change ext4_es_try_to_merge_left() to return whichever extent_status
> should be recorded in tree->cache_es. Remove cache_es update from
> both of them, leaving that to ext4_es_insert_extent()'s out label.
>
> Signed-off-by: Hugh Dickins <hughd@google.com>

Hugh, thanks for finding this bug!

Zheng, you were going to send me an updated patch series; can you take
care of merging this patch into your patch series (and crediting Hugh
with a Signed-off-by as appropriate)?

Thanks!!

- Ted


\
 
 \ /
  Last update: 2012-09-27 23:21    [W:0.040 / U:0.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site