Am 23.10.2014 um 11:11 hat Max Reitz geschrieben:
Leaves the question, is it worth the hassle?
Probably not. Would you be fine with setting bs->drv to NULL in the
problematic error paths?
By calling qcow2_signal_corruption(), right? I think that's fine.
I don't know. The image isn't corrupted, it's just dirty. When you
open it, it'll work fine. I'd just output an own error here and set
bs->drv to NULL.
Okay.
What about the assumption that 3 + l1_size fits in one refcount block?
Do we need to check it even now?
The alternative would be not to allocate 3 + l1_size, but rather
just 3. Then we have a working refcount structure and that's the
most important thing (the L1 table is not yet accounted for, but
repair can fix that).
Afterwards, we allocate the L1 table. With this change, we don't
know its offset yet, so we may have to change it again. But we can
easily do that by just setting s->l1_size to 0 and call
qcow2_grow_l1_table().
How do you make sure that the L1 table always stays zeroed then?