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@xxxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
