bad tree block start

Hi,

the computer froze for a few seconds then this appeared in the log:

btrfs bad tree block start 9407756905013237084 32178176

There was no other messages from btrfs. I can mount, unmount, read, write and all the data seems to be there. What does it mean? My guess is that there was some kind of corruption and it was corrected by the raid1.

// Maria