Restore almost all files from non-mountable filesystem

Restore almost all files from non-mountable filesystem

[Christian Rädel]

$> uname -a

Linux core 5.5.2-arch1-1 #1 SMP PREEMPT Tue, 04 Feb 2020 18:56:18
+0000 x86_64 GNU/Linux

$> btrfs --version

btrfs-progs v5.4.1

$> btrfs fi show /dev/sdd1

Label: 'data'  uuid: 5bdd91dd-8a61-408d-9a22-f2f10293c36e
Total devices 1 FS bytes used 2.92TiB
devid    1 size 3.64TiB used 3.15TiB path /dev/sdd1

$> mount -o compress=lzo,clear_cache,nospace_cache,ro -L data /media/data

mount: /media/data: wrong fs type, bad option, bad superblock on
/dev/sdd1, missing                            codepage or helper
program, or other error.

$> dmesg | grep -i btrfs

[    2.846524] Btrfs loaded, crc32c=crc32c-intel
[    2.851902] BTRFS: device label data devid 1 transid 45682
/dev/sdd1 scanned by systemd-udevd (232)
[ 3704.305920] BTRFS info (device sdd1): use lzo compression, level 0
[ 3704.305923] BTRFS info (device sdd1): force clearing of disk cache
[ 3704.305925] BTRFS info (device sdd1): disabling disk space caching
[ 3704.305926] BTRFS info (device sdd1): has skinny extents
[ 3704.989970] BTRFS error (device sdd1): parent transid verify failed
on 33357824 wanted 45668 found 45681
[ 3704.990327] BTRFS error (device sdd1): parent transid verify failed
on 33357824 wanted 45668 found 45681
[ 3704.990336] BTRFS warning (device sdd1): failed to read root (objectid=4): -5
[ 3705.042892] BTRFS error (device sdd1): open_ctree failed

Hi,

I've done a

$> btrfs restore -m -S /dev/sdd1 /media/backup
parent transid verify failed on 33357824 wanted 45668 found 45681
parent transid verify failed on 33357824 wanted 45668 found 45681
parent transid verify failed on 33357824 wanted 45668 found 45681
Ignoring transid failure
parent transid verify failed on 31899648 wanted 45662 found 45680
parent transid verify failed on 31899648 wanted 45662 found 45680
parent transid verify failed on 31899648 wanted 45662 found 45680
Ignoring transid failure

but it has found nothing. After experimenting with the parameters -d
and --path-regex, it has found some deleted files, maybe from the root
directory. So my question: How to restore almost all files that can be
restored with the btrfs restore command without a knowledge of the
directory structure? By the way: There exists an application called
Reclaime (for Windows) that can scan and find all my files, and is
able to show/play them. But since it is only an evaluation version, I
cannot save anything.

Sincerly,
Christian