Messages in this thread | | | Date | Fri, 28 Sep 2012 06:53:57 +0800 | From | Zheng Liu <> | Subject | Re: [PATCH next/mmotm] ext4: fix cache_es after merge_left |
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On Thu, Sep 27, 2012 at 04:39:20PM -0400, Theodore Ts'o wrote: > 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)?
Yeah, thanks for fixing it, although I have fixed this problem in my new patch set. I will add a Signed-off-by into the patch.
Regards, Zheng
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