On Mon 18-12-23 15:43:42, Jan Kara wrote: > On Mon 18-12-23 22:18:14, Baokun Li wrote: > > When bb_free is not 0 but bb_fragments is 0, return directly to avoid > > system crash due to division by zero. > > How could this possibly happen? bb_fragments is the number of free space > extents and bb_free is the number of free blocks. No free space extents => > no free blocks seems pretty obvious? You can see the logic in > ext4_mb_generate_buddy()... Oh, I see. This is probably about "bitmap corrupted case". But still both allocation and freeing of blocks shouldn't operate on bitmaps marked as corrupted so this should not happen? Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR