I don't know, maybe. This is not a new file system, clearly, it has half million+ generations.
backup_roots[4]: backup 0: backup_tree_root: 29360128 gen: 593817 level: 1 backup_chunk_root: 20971520 gen: 591139 level: 1 backup_extent_root: 29376512 gen: 593817 level: 1 backup_fs_root: 132562944 gen: 593815 level: 0 backup_dev_root: 29409280 gen: 593817 level: 0 backup_csum_root: 29491200 gen: 593817 level: 0 backup_total_bytes: 254007050240 backup_bytes_used: 43532288 backup_num_devices: 1 backup 1: backup_tree_root: 138821632 gen: 593818 level: 0 backup_chunk_root: 21020672 gen: 593818 level: 0 backup_extent_root: 138805248 gen: 593818 level: 0 backup_fs_root: 132562944 gen: 593815 level: 0 backup_dev_root: 132841472 gen: 593818 level: 0 backup_csum_root: 138870784 gen: 593818 level: 0 backup_total_bytes: 254007050240 backup_bytes_used: 655360 backup_num_devices: 1 The old chunk root and tree root might come in handy, from backup0, which is the generation prior to the one currently set in the super blocks. The bytes_used vs dev_item.bytes_used is also interesting, huge difference. So it looks like this was umounted very soon after you realized what you did. What do you get for btrfs restore -l <dev> Maybe just try this, which is the oldest generation we know about right now, which is found in backup root 2. sudo btrfs restore -D -v -t 138788864 /dev/mapper/brick1 . That's a dry run so the path to save stuff to doesn't matter, so I'm just using . for that. But what you'll get is a file listing. If there's nothing listed, then it's a dead end. But if it's listing everything you want, it's a win. Just point to a proper destination and remove -D. However, another possibility is that it's a partial - i.e. it might be a generation in between the cleaner running, so some stuff is restored but not all of it. Yeah, maybe there's a way to get an older generation and root with an older copy of btrfs-progs. I think the current one isn't working very well...on yet another file system I have that is very new (week) but has hours of writes on it, [chris@f25s ~]$ sudo btrfs-find-root /dev/mapper/brick1 Superblock thinks the generation is 5727 Superblock thinks the level is 1 Found tree root at 426847567872 gen 5727 level 1 That's it. So no hang, but only one tree root which is just bogus. Even the superblock has more information than this. I'm used to seeing dozens or more. Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html