Bug#579005: XFS internal error xfs_da_do_buf(2) at line 2085 of file fs/xfs/xfs_da_btree.c.
Jonathan Nieder wrote:
> Interesting. So this might be a case of the kernel not coping well
> with previous filesystem corruption.
Some reading: 
>From similar symptoms at :
| This indicates filesystem corruption, which may be caused by a hardware/media
| I suggest you run xfs_repair and then xfs_db to dump any inodes that may have
| Also check smartctl, dmesg etc for any hardware errors.
| This class of fault is typically very hard to track down, the corruption
| (whether caused by software or hardware) may have happened a week ago and
| its only now you have read that part of the filesystem again.
Apparently one cause of this in olden days was  (probably not
what's happening here, since that got fixed a while ago). Another was
running with write cache enabled but without barriers which didn't
work over the device mapper.
In any case, I think reporting "XFS internal error" rather than
something more enlightening like "magic number is wrong - filesystem
is probably corrupt" is a bug in itself. So it would be nice to
figure out what happened and at least fix this that much.
Hope that helps,