Re: Recover from "couldn't read tree root"?
From: Nathan Dehnel <hidden>
Date: 2021-06-20 21:32:15
Was bcache in write back or write through mode?
Writeback.
What's the configuration?
NAME FSTYPE SIZE FSUSE% MOUNTPOINT
UUID MIN-IO SCHED DISC-GRAN
MODEL
loop0 squashfs 655.6M 100% /run/archiso/sfs/airootfs
512 mq-deadline 0B
sda 238.5G
512 mq-deadline 512B
C300-CTFDDAC256MAG
├─sda1 2M
512 mq-deadline 512B
├─sda2 linux_raid_member 512M
325a2f12-18b8-27f7-2f81-f554a9b0fccc 512 mq-deadline 512B
│ └─md126 vfat 511.9M
EF35-0411 512 512B
└─sda3 linux_raid_member 16G
93ed641f-394b-2122-7525-b3311aaac6b8 512 mq-deadline 512B
└─md125 swap 16G
9ea84fb7-8bd7-4a0e-91fe-398790643066 1048576 512B
sdb 232.9G
512 mq-deadline 512B
Samsung_SSD_850_EVO_250GB
├─sdb1 2M
512 mq-deadline 512B
├─sdb2 linux_raid_member 512M
325a2f12-18b8-27f7-2f81-f554a9b0fccc 512 mq-deadline 512B
│ └─md126 vfat 511.9M
EF35-0411 512 512B
└─sdb3 linux_raid_member 16G
93ed641f-394b-2122-7525-b3311aaac6b8 512 mq-deadline 512B
└─md125 swap 16G
9ea84fb7-8bd7-4a0e-91fe-398790643066 1048576 512B
sdc btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Z3A0
└─sdc1 bcache 931.5G
f34b26ea-8229-4f3f-bdc5-29c5fe16eaae 512 mq-deadline 0B
└─bcache0 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdd btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Z3A0
└─sdd1 bcache 931.5G
beb25260-1b36-473f-93c4-7ef016a62f44 512 mq-deadline 0B
└─bcache1 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sde btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 4096 mq-deadline 0B
WDC_WD1003FZEX-00MK2A0
└─sde1 bcache 931.5G
21b55c83-c951-4e4f-affc-0b9bf54c8783 4096 mq-deadline 0B
└─bcache2 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdf btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Z3A0
└─sdf1 bcache 931.5G
d4d2b9d6-077d-4328-b2cd-14f6db259955 512 mq-deadline 0B
└─bcache3 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdg btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
ST1000NM0011
└─sdg1 bcache 931.5G
a8513a01-c6be-4bec-b3f9-a5797225d304 512 mq-deadline 0B
└─bcache4 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdh 931.5G
512 mq-deadline 0B
WDC_WD1002FAEX-00Z3A0
└─sdh1 bcache 931.5G
ffeacab7-ff42-453c-b012-58b119236fa5 512 mq-deadline 0B
└─bcache5 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdi btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Y9A0
└─sdi1 bcache 931.5G
f3f4d706-7d73-4b48-a5b3-9802fc0de978 512 mq-deadline 0B
└─bcache6 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdj btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 4096 mq-deadline 0B
WDC_WD1003FZEX-00MK2A0
└─sdj1 bcache 931.5G
64d10dda-4ac2-44d4-941a-362ccb5ddbba 4096 mq-deadline 0B
└─bcache7 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdk btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Y9A0
└─sdk1 bcache 931.5G
c3ddc718-f700-4360-82c9-7db76114e3f6 512 mq-deadline 0B
└─bcache8 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdl btrfs 931.5G
12bcde5c-b3ae-4fa6-8e17-0a4b564f1ba1 512 mq-deadline 0B
WDC_WD1002FAEX-00Z3A0
└─sdl1 bcache 931.5G
2bf5ac80-cdf6-4c0c-9434-bcdc4626abff 512 mq-deadline 0B
└─bcache9 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
sdm iso9660 14.9G
2021-05-08-11-22-02-00 512 mq-deadline 0B
USB_2.0_FD
├─sdm1 iso9660 717M 100% /run/archiso/bootmnt
2021-05-08-11-22-02-00 512 mq-deadline 0B
└─sdm2 vfat 1.4M
0A52-44A0 512 mq-deadline 0B
nvme0n1 linux_raid_member 13.4G
4703551c-4570-b6c8-7dda-991b93b99c9a 512 none 512B
INTEL MEMPEK1W016GA
└─md127 bcache 13.4G
dfda7dc0-07a4-40bf-b5b8-e3458c181ce4 16384 512B
├─bcache0 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache1 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache2 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache3 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache4 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache5 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache6 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache7 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache8 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
└─bcache9 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
nvme1n1 linux_raid_member 13.4G
4703551c-4570-b6c8-7dda-991b93b99c9a 512 none 512B
INTEL MEMPEK1W016GA
└─md127 bcache 13.4G
dfda7dc0-07a4-40bf-b5b8-e3458c181ce4 16384 512B
├─bcache0 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache1 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache2 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache3 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache4 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache5 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache6 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache7 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
├─bcache8 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
└─bcache9 btrfs 931.5G
76189222-b60d-4402-a7ff-141f057e8574 512 512B
On Sun, Jun 20, 2021 at 9:09 PM Chris Murphy [off-list ref] wrote:On Sun, Jun 20, 2021 at 2:38 PM Nathan Dehnel [off-list ref] wrote:quoted
A machine failed to boot, so I tried to mount its root partition from systemrescuecd, which failed: [ 5404.240019] BTRFS info (device bcache3): disk space caching is enabled [ 5404.240022] BTRFS info (device bcache3): has skinny extents [ 5404.243195] BTRFS error (device bcache3): parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 [ 5404.243279] BTRFS error (device bcache3): parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 [ 5404.243362] BTRFS error (device bcache3): parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 [ 5404.243432] BTRFS error (device bcache3): parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 [ 5404.243435] BTRFS warning (device bcache3): couldn't read tree root [ 5404.244114] BTRFS error (device bcache3): open_ctree failed btrfs rescue super-recover -v /dev/bcache0 returned this: parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 parent transid verify failed on 3004631449600 wanted 1420882 found 1420435 Ignoring transid failure ERROR: could not setup extent tree Failed to recover bad superblocks uname -a: Linux sysrescue 5.10.34-1-lts #1 SMP Sun, 02 May 2021 12:41:09 +0000 x86_64 GNU/Linux btrfs --version: btrfs-progs v5.10.1 btrfs fi show: Label: none uuid: 76189222-b60d-4402-a7ff-141f057e8574 Total devices 10 FS bytes used 1.50TiB devid 1 size 931.51GiB used 311.03GiB path /dev/bcache3 devid 2 size 931.51GiB used 311.00GiB path /dev/bcache2 devid 3 size 931.51GiB used 311.00GiB path /dev/bcache1 devid 4 size 931.51GiB used 311.00GiB path /dev/bcache0 devid 5 size 931.51GiB used 311.00GiB path /dev/bcache4 devid 6 size 931.51GiB used 311.00GiB path /dev/bcache8 devid 7 size 931.51GiB used 311.00GiB path /dev/bcache6 devid 8 size 931.51GiB used 311.03GiB path /dev/bcache9 devid 9 size 931.51GiB used 311.03GiB path /dev/bcache7 devid 10 size 931.51GiB used 311.03GiB path /dev/bcache5 Is this filesystem recoverable?quoted
(Sorry, re-sending because I forgot to add a subject)Definitely don't write any irreversible changes, such as a repair attempt, to anything until you understand what what wrong or it'll make recovery harder or impossible. Was bcache in write back or write through mode? What's the configuration? Can you supply something like lsblk -o NAME,FSTYPE,SIZE,FSUSE%,MOUNTPOINT,UUID,MIN-IO,SCHED,DISC-GRAN,MODEL -- Chris Murphy