Device Delete Stalls - Addition

[Stefan Malte Schumacher <s.schumacher@xxxxxxxxxxxxx>]

Hello everybody,

I think this might be useful:

root@mars:~# btrfs dev usage /mnt/btrfs-raid/
/dev/sda, ID: 1
   Device size:             3.64TiB
   Device slack:              0.00B
   Data,RAID1:              7.00GiB
   Metadata,RAID1:          1.00GiB
   Unallocated:             3.63TiB

Yours sincerely
Stefan