btrfs fails to mount on kernel 5.11.4 but works on 5.10.19

[Norbert Preining]

Dear all

(please cc)

not sure this is the right mailing list, but I cannot boot into 5.11.4 
it gives me
        devid 9 uui .....
        failed to read the system array: -2
        open_ctree failed
(only partial, typed in from photo)

OTOH, 5.10.19 boots without a hinch
$ btrfs fi show /
Label: none  uuid: 911600cb-bd76-4299-9445-666382e8ad20
        Total devices 8 FS bytes used 3.28TiB
        devid    1 size 899.01GiB used 670.00GiB path /dev/sdb3
        devid    2 size 489.05GiB used 271.00GiB path /dev/sdd
        devid    3 size 1.82TiB used 1.58TiB path /dev/sde1
        devid    4 size 931.51GiB used 708.00GiB path /dev/sdf1
        devid    5 size 1.82TiB used 1.58TiB path /dev/sdc1
        devid    7 size 931.51GiB used 675.00GiB path /dev/nvme2n1p1
        devid    8 size 931.51GiB used 680.03GiB path /dev/nvme1n1p1
        devid    9 size 931.51GiB used 678.03GiB path /dev/nvme0n1p1

That is a multi disk array with all data duplicated data/sys:

$ btrfs fi us -T /
Overall:
    Device size:                   8.63TiB
    Device allocated:              6.76TiB
    Device unallocated:            1.87TiB
    Device missing:                  0.00B
    Used:                          6.57TiB
    Free (estimated):              1.03TiB      (min: 1.03TiB)
    Free (statfs, df):             1.01TiB
    Data ratio:                       2.00
    Metadata ratio:                   2.00
    Global reserve:              512.00MiB      (used: 0.00B)
    Multiple profiles:                  no

                  Data      Metadata System               
Id Path           RAID1     RAID1    RAID1     Unallocated
-- -------------- --------- -------- --------- -----------
 1 /dev/sdb3      662.00GiB  8.00GiB         -   229.01GiB
 2 /dev/sdd       271.00GiB        -         -     1.55TiB
 3 /dev/sde1        1.58TiB  7.00GiB         -   241.02GiB
 4 /dev/sdf1      701.00GiB  7.00GiB         -   223.51GiB
 5 /dev/sdc1        1.57TiB 10.00GiB         -   241.02GiB
 7 /dev/nvme2n1p1 675.00GiB        -         -   256.51GiB
 8 /dev/nvme1n1p1 673.00GiB  7.00GiB  32.00MiB   251.48GiB
 9 /dev/nvme0n1p1 671.00GiB  7.00GiB  32.00MiB   253.48GiB
-- -------------- --------- -------- --------- -----------
   Total            3.36TiB 23.00GiB  32.00MiB     3.21TiB
   Used             3.27TiB 15.70GiB 528.00KiB            
$

Is there something wrong with the filesystem? Or the kernel?
Any hint how to debug this?

(Please cc)

Thanks

Norbert

--
PREINING Norbert                              https://www.preining.info
Fujitsu Research Labs  +  IFMGA Guide + TU Wien + TeX Live + Debian Dev
GPG: 0x860CDC13   fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13