BitmapActionStartwrite
llbitmap_state_machine(llbitmap, start, end, BitmapActionStartwrite);
llbitmap_state_machine(mddev->bitmap, s, e, BitmapActionStartwrite);
[BitmapActionStartwrite] = BitDirty,
[BitmapActionStartwrite] = BitDirty,
[BitmapActionStartwrite] = BitNone,
[BitmapActionStartwrite] = BitNone,
[BitmapActionStartwrite] = BitNone,
action == BitmapActionStartwrite)
action == BitmapActionStartwrite && level_456) {