Hi,
I have a btrfs with bcache setup that failed during a boot yesterday.
There is one SSD with bcache that is used as a cache for 3 btrfs HDDs.
Reading through a number of discussions, I've decided to ask for advice here.
Should I be running "btrfs check --recover"?
The last message in the dmesg log is this one:
Btrfs loaded, crc32c=crc32c-intel
BTRFS: device label root devid 3 transid 138434 /dev/bcache2 scanned
by btrfs (341)
BTRFS: device label root devid 2 transid 138434 /dev/bcache1 scanned
by btrfs (341)
BTRFS: device label root devid 1 transid 138434 /dev/bcache0 scanned
by btrfs (341)
BTRFS info (device bcache0): disk space caching is enabled
BTRFS info (device bcache0): has skinny extents
BTRFS error (device bcache0): parent transid verify failed on
16984159518720 wanted 138414 found 138207
BTRFS error (device bcache0): parent transid verify failed on
16984159518720 wanted 138414 found 138207
BTRFS error (device bcache0): open_ctree failed
Trying to mount it in the recovery mode does not seem to work:
(initramfs) mount -t btrfs -o ro,usebackuproot /dev/bcache0 /mnt
BTRFS info (device bcache1): trying to use backup root at mount time
BTRFS info (device bcache1): disk space caching is enabled
BTRFS info (device bcache1): has skinny extents
BTRFS error (device bcache1): parent transid verify failed on
16984159518720 wanted 138414 found 138207
BTRFS error (device bcache1): parent transid verify failed on
16984159518720 wanted 138414 found 138207
BTRFS error (device bcache1): parent transid verify failed on
16984173199360 wanted 138433 found 138195
BTRFS error (device bcache1): parent transid verify failed on
16984173199360 wanted 138433 found 138195
BTRFS warning (device bcache1): failed to read tree root
BTRFS error (device bcache1): parent transid verify failed on
16984171298816 wanted 138431 found 131157
BTRFS error (device bcache1): parent transid verify failed on
16984171298816 wanted 138431 found 131157
BTRFS warning (device bcache1): failed to read tree root
BTRFS critical (device bcache1): corrupt leaf: block=16984183013376
slot=36 extent bytenr=11447166291968 len=262144 invalid generation,
have 138434 expect (0, 138433]
BTRFS error (device bcache1): block=16984183013376 read time tree
block corruption detected
BTRFS critical (device bcache1): corrupt leaf: block=16984183013376
slot=36 extent bytenr=11447166291968 len=262144 invalid generation,
have 138434 expect (0, 138433]
BTRFS error (device bcache1): block=16984183013376 read time tree
block corruption detected
BTRFS warning (device bcache1): failed to read tree root
BUG: kernel NULL pointer dereference, address: 000000000000001f
#PF: supervisor read access in kernel mode
<a stack trace follows>
(initramfs) btrfs --version
btrfs-progs v5.4.1
(initramfs) uname -a
Linux (none) 5.6.11-050611-generic #202005061022 SMP Wed May 6 10:27:04
UTC 2020 x86_64 GNU/Linux
(initramfs) btrfs fi show
Label: 'root' uuid: 0a3d051b-72ef-4a5d-8a48-eb0dbb960b56
Total devices 3 FS bytes used 6.55TiB
devid 1 size 3.64TiB used 1.62TiB path /dev/bcache1
devid 2 size 7.28TiB used 5.21TiB path /dev/bcache0
devid 3 size 12.73TiB used 6.80TiB path /dev/bcache2
I have tried booting using a live ISO with 5.8.0 kernel and btrfs v5.6.1
from http://defender.exton.net/.
After booting tried mounting the bcache using the same command as above.
The only message in the console was "Killed".
/dev/kmsg on the other hand lists messages very similar to the ones I've
seen in the initramfs environment: https://pastebin.com/Vhy072Mx
P.S. Please CC me, as I am not subscribed.
Thank you,
Illia Bobyr
