[AshamedCaptain]

This just can't happen with btrfs since the _old_ block tree should be still in the disk somewhere. i.e. to corrupt the image so that btrfs shits itself is easy to do, but the _previous_ version of the data is still there by construction and if you are already manipulating the data structures it should be easy enough to just point the sb to it.

The worst issue I've ever had with btrfs simply required zeroing the journal (by hand -- both the kernel and *fsck tools would crash when reading it). The first time I reported the issue to the mailing list and the underlying issue was promptly fixed. However, it still happened a second time, and I didn't bother reporting it. As many people say on this thread, once is too many when it comes to filesystems.