btrfs defrag: success or failure?

Hi everyone,

I got the following message:

# btrfs fi defrag -r /home
ERROR: defrag failed on /home/user/.dropbox-dist/dropbox: Success
total 1 failures

I feel that something went wrong, but the message is a bit misleading.

Anyway: Provided that Dropbox is running in the system, does it mean that it cannot be defagmented?

With best regards,
Dmitry