I'd say backup the volume conventionally to get important data secured. Then use btrfs check --repair to fix the problems with the file system, and then try the btrfs send receive again.
It most certainly is a bug, but it's not clear to me what the cause is; other than the kernel isn't handling the problem on-disk gracefully. Maybe repair will fix it. Another possibility is to move to kernel 4.9.0 and see if it still reproduces. Per usual, there's a ton of bug fixes in each kernel release. Otherwise I'm out of ideas. Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
