Comment 12 for bug 1529146

I do confirm that btrfs balance causes hard lockups here, with the same error. The raid1 is freshly modified (sdd is brand new) so had a lot to balance - didnt see the problem with the previous sdd that got replaced. Letting it balance when the box is idle (nighttime, no logged users) was OK, bu trying to do stuff at the same time locked it randomly.

This is my layout:

$ btrfs fi show /mnt/btrfs_pool/
Label: none uuid: 8aef485a-3e5e-4f45-96dd-44ee9d41fb09
        Total devices 2 FS bytes used 227.66GiB
        devid 1 size 931.51GiB used 229.03GiB path /dev/sdd1
        devid 2 size 931.51GiB used 229.03GiB path /dev/sdc1

$ btrfs fi df /mnt/btrfs_pool/
Data, RAID1: total=227.00GiB, used=226.36GiB
System, RAID1: total=32.00MiB, used=48.00KiB
Metadata, RAID1: total=2.00GiB, used=1.29GiB
GlobalReserve, single: total=448.00MiB, used=0.00B

$ btrfs fi show /mnt/backups/
Label: none uuid: 49963f07-64bf-427c-864e-c7a9b4bbcdf4
        Total devices 1 FS bytes used 227.33GiB
        devid 1 size 465.76GiB used 235.02GiB path /dev/sda1

$ uname -a
Linux cygn 4.2.6-301.fc23.x86_64 #1 SMP Fri Nov 20 22:22:41 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux