filesystem issues after abrupt powerloss.

[kenneth topp <ken@bllue.org>]

greetings,

my btrfs on luks device is having troubles again.  I believe the system 
abruptly powerdown due to heat.

I believe my backups are in good order.  Does anyone have any 
suggestions how to recover this filesystem by running a check  --repair 
or scrub?    Should I trust such a recovery or just recreate the 
filesystem from backups.

Are there any other debugging commands I can run to provide more 
information?

Are there any known defects in the filesystem that would explain how 
this filesystem got so corrupt?

relevent part of dmesg:

[ 1381.291103] BTRFS warning (device dm-22): 'recovery' is deprecated, 
use 'usebackuproot' instead
[ 1381.291104] BTRFS info (device dm-22): trying to use backup root at 
mount time
[ 1381.291105] BTRFS info (device dm-22): using free space tree
[ 1381.291106] BTRFS info (device dm-22): has skinny extents
[ 1488.716374] BTRFS info (device dm-22): checking UUID tree
[ 1520.983660] BTRFS error (device dm-22): parent transid verify failed 
on 19934974361600 wanted 675675 found 675394
[ 1520.984138] BTRFS error (device dm-22): parent transid verify failed 
on 19934974361600 wanted 675675 found 675394
[ 1520.984151] BTRFS: error (device dm-22) in __btrfs_free_extent:3080: 
errno=-5 IO failure
[ 1520.984157] BTRFS info (device dm-22): forced readonly
[ 1520.984163] BTRFS: error (device dm-22) in 
btrfs_run_delayed_refs:2188: errno=-5 IO failure

rest of diagnostics

#   uname -a
Linux static.myhost 5.4.52-100.fc32.x86_64 #1 SMP Thu Jul 16 12:00:22 
EDT 2020 x86_64 x86_64 x86_64 GNU/Linux
#   btrfs --version
btrfs-progs v5.7
#   btrfs fi show
Label: 't2'  uuid: ce50d21c-7727-4a53-b804-d02480643dfa
         Total devices 2 FS bytes used 640.00KiB
         devid    1 size 447.13GiB used 2.01GiB path /dev/mapper/cprt-30
         devid    2 size 447.13GiB used 2.01GiB path /dev/mapper/cprt-31

Label: 'btm'  uuid: 0a5b42a7-0e39-48fa-be1f-4aa29bc323f2
         Total devices 2 FS bytes used 27.34TiB
         devid    1 size 14.55TiB used 13.70TiB path /dev/mapper/cprt-50
         devid    2 size 14.55TiB used 13.70TiB path /dev/mapper/cprt-53
# btrfs fi df /mnt
Data, single: total=27.31TiB, used=27.30TiB
System, RAID1: total=32.00MiB, used=2.88MiB
Metadata, RAID1: total=47.00GiB, used=46.72GiB
GlobalReserve, single: total=512.00MiB, used=0.00B




thanks,

ken