btrfs filesystem usage - Wrong Unallocated indications - RAID10

[Marco Lorenzo Crociani <marcoc@prismatelecomtesting.com>]

Hi,
as I wrote today in IRCI experienced an issue with 'btrfs filesystem usage'.
I have a 4 partitions RAID10 btrfs filesystem almost full.
'btrfs filesystem usage' reports wrong "Unallocated" indications.

Linux 4.5.3
btrfs-progs v4.5.3


# btrfs fi usage /data/

Overall:
     Device size:          13.93TiB
     Device allocated:          13.77TiB
     Device unallocated:         167.54GiB
     Device missing:             0.00B
     Used:              13.44TiB
     Free (estimated):         244.39GiB    (min: 244.39GiB)
     Data ratio:                  2.00
     Metadata ratio:              2.00
     Global reserve:         512.00MiB    (used: 0.00B)

Data,single: Size:8.00MiB, Used:0.00B
    /dev/sda4       8.00MiB

Data,RAID10: Size:6.87TiB, Used:6.71TiB
    /dev/sda4       1.72TiB
    /dev/sdb3       1.72TiB
    /dev/sdc3       1.72TiB
    /dev/sdd3       1.72TiB

Metadata,single: Size:8.00MiB, Used:0.00B
    /dev/sda4       8.00MiB

Metadata,RAID10: Size:19.00GiB, Used:14.15GiB
    /dev/sda4       4.75GiB
    /dev/sdb3       4.75GiB
    /dev/sdc3       4.75GiB
    /dev/sdd3       4.75GiB

System,single: Size:4.00MiB, Used:0.00B
    /dev/sda4       4.00MiB

System,RAID10: Size:16.00MiB, Used:768.00KiB
    /dev/sda4       4.00MiB
    /dev/sdb3       4.00MiB
    /dev/sdc3       4.00MiB
    /dev/sdd3       4.00MiB

Unallocated:
    /dev/sda4       1.76TiB
    /dev/sdb3       1.76TiB
    /dev/sdc3       1.76TiB
    /dev/sdd3       1.76TiB

----------------------------------------------------------------------------------
# btrfs fi show /data/
Label: 'data'  uuid: df6639d5-3ef2-4ff6-a871-9ede440e2dae
     Total devices 4 FS bytes used 6.72TiB
     devid    1 size 3.48TiB used 3.44TiB path /dev/sda4
     devid    2 size 3.48TiB used 3.44TiB path /dev/sdb3
     devid    3 size 3.48TiB used 3.44TiB path /dev/sdc3
     devid    4 size 3.48TiB used 3.44TiB path /dev/sdd3

----------------------------------------------------------------------------------
# btrfs fi df /data/
Data, RAID10: total=6.87TiB, used=6.71TiB
Data, single: total=8.00MiB, used=0.00B
System, RAID10: total=16.00MiB, used=768.00KiB
System, single: total=4.00MiB, used=0.00B
Metadata, RAID10: total=19.00GiB, used=14.15GiB
Metadata, single: total=8.00MiB, used=0.00B
GlobalReserve, single: total=512.00MiB, used=0.00B

----------------------------------------------------------------------------------
# df -h
/dev/sda4                     7,0T  6,8T    245G  97% /data

Regards,

-- 
Marco Crociani
Prisma Telecom Testing S.r.l.
via Petrocchi, 4  20127 MILANO  ITALY
Phone:  +39 02 26113507
Fax:  +39 02 26113597
e-mail:  marcoc@prismatelecomtesting.com
web:  http://www.prismatelecomtesting.com

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