Re: BTRFS critical (device dm-0): invalid dir item name len: 45389

[john terragon <jterragon@gmail.com>]

Everyone knows what raid0 entails. Moreover, with btrfs being an
experimental fs, not having backups would obviously be pure idiocy.

I wrote that it was "pretty serious" because the situation came out of
nowhere on a low-traffic fs on which the most exiciting thing that can
happen is an occasional snapshot once on a while when I do a heavy
update with apt-get (snapshot that gets always removed right after the
update goes invariably well and my paranoia fades).
The problem seems to have happen right after a hard lock probably due
to 3.17.0-rc3 (and before you explain to me what that rc3 stands for,
let me tell you that I'm not complaining, I knew what I was doing). I
had to power-off "brutally" and right after that the problem occurred.
I'm pretty sure about that because for obvious reasons I rsync the
hell out of that filesystem  every chance I get. Rsync obviously does
a traversal of the fs and so the "critical" (btrfs words, not mine)
problem would have showed on kmsg (another place that I watch like a
hawk, because of the raid0+experimental fs thing).

I don't know if you are a btrfs developer but that "pretty serious"
was not meant to offend them nor to complain. Actually I've been a
pretty happy customer up until now (and I still am) because I have
never been bitten by any big bug even with such a complex fs. I just
have this zombie directory that can't be rm'd, but I mv'd out of the
way and everything is fine. It'll get sorted when I do the next
wipe-and-restore iteration (again, being experimental, I don't let the
fs to become too "old").
So, the "pretty serious" was more due to the surprise than anything else.

John