Re: parent transid verify failed

From: Eric Levy <contact@ericlevy.name>
To: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: parent transid verify failed
Date: Sat, 01 Jan 2022 16:58:58 -0500	[thread overview]
Message-ID: <59a9506eb880b054f8eff90d5b26ad0c673c7e1f.camel@ericlevy.name> (raw)
In-Reply-To: <YdDAGLU7M5mx7rL8@hungrycats.org>

Here is the new information:

1) Previously, the system log from R/W mount attempt, which failed:

Dec 31 15:15:48 hostname sudo[1477409]:      user : TTY=pts/0 ; PWD=/home/user ; USER=root ; COMMAND=/usr/bin/mount -o skip_balance /dev/sdc1
Dec 31 15:15:48 hostname sudo[1477409]: pam_unix(sudo:session): session opened for user root by (uid=0)
Dec 31 15:15:48 hostname sudo[1477409]: pam_unix(sudo:session): session closed for user root
Dec 31 15:15:48 hostname kernel: BTRFS info (device sdc1): disk space caching is enabled
Dec 31 15:15:48 hostname kernel: BTRFS error (device sdc1): Remounting read-write after error is not allowed

2) Same, but in RO:

Dec 31 15:14:50 hostname sudo[1477248]:      user : TTY=pts/0 ; PWD=/home/user ; USER=root ; COMMAND=/usr/bin/mount -o skip_balance,ro /dev/sdc1
Dec 31 15:14:50 hostname sudo[1477248]: pam_unix(sudo:session): session opened for user root by (uid=0)
Dec 31 15:14:50 hostname sudo[1477248]: pam_unix(sudo:session): session closed for user root
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (Device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675
Dec 31 15:14:50 hostname kernel: BTRFS error (device sdc1): parent transid verify failed on 867434496 wanted 9212 found 8675

3) After running iSCSI logout, and login, the devices were assigned new
names (sdc -> sdf, sdd -> sde). Then checking with readonly flag, using
admin tools, while unmounted:

$ sudo btrfs check --readonly /dev/sdf1
Opening filesystem to check...
Checking filesystem on /dev/sdf1
UUID: c6f83d24-1ac3-4417-bdd9-6249c899604d
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs
[7/7] checking quota groups skipped (not enabled on this FS)
found 266107584512 bytes used, no error found
total csum bytes: 259546380
total tree bytes: 586268672
total fs tree bytes: 214188032
total extent tree bytes: 52609024
btree space waste bytes: 89657360
file data blocks allocated: 1019677446144
 referenced 300654301184

4) However, mount still fails. Here is log output from trying to mount
/dev/sdf1:

kernel: BTRFS warning: duplicate device /dev/sdf1 devid 1 generation 9211 scanned by mount (1641108)

5) Same kind of results for /dev/sde:

kernel: BTRFS warning: duplicate device /dev/sde devid 2 generation 9211 scanned by mount (1642247)