buttersink and btrfs quota issues

[ChojinDSL]

When I run buttersink on a directory with snapshots, it hangs with the message "Waiting for btrfs quota usage scan"

When I run "btrfs quota rescan -s /", it seems as if the quota scan never seems to end, as the ID never changes.

Is there any way I can abort a quota scan, or perhaps force it to rescan?
I'm guessing this process is rather essential for buttersink's functionality?

[ChojinDSL]

I think I've found what causes the issue. Apparently, if you have either the source or target BTRFS partition mounted with "autodefrag", then btrfs quota scan can hang.

At least, that's how it seems on my servers. Keep in mind, this is with Debian Wheezy 64bit. Kernel 3.16 but btrfs tools 3.17 and on some servers btrfs tools 4.4.

Remounting the partitions without autodefrag seems to fix it. (At least after a reboot).