Hello. A friend and I were wroking on something using LUFS,
and I think we have found a problem with XFS and LUFS. If
we mount an XFS filesystem through LUFS (tested with
localfs), and try to copy files into that directory, sometimes
during the copy the file is truncated.
This is how to reproduce it:

- Set up and mount an XFS filesystem. In this case, it's
  mounted on /xfs

- Go to /xfs and create two directories, /xfs/a and /xfs/b

- cd /xfs ;  lufsmount localfs:// a

- cd /xfs/a/xfs/b  (yes, the "xfs/b" inside "xfs/a")

- Find a directory, preferably with big files (let's call it
  /bigdirectory/), and copy it into "b":  cp -a /bigdirectory/ .

- Verify the copy. In this test, in the copied directory (b),
  sometimes files are truncated. In one case, the size went
  from 37M to 16M *during* the copy (we kept checking with
  "ls -l" while "cp -a" hadn't finished. The file size grew for a
  while, then shrank and started to grow again)

Using ext2, ext3, or reiserfs, the problem doesn happen
(tested a dozen times with each one).

The kernel being used is 2.9.10 from kernel.org, and the
LUFS version is the Debian version 0.9.7-5, based on LUFS
v0.9.7. The cp version is the one in Debian Sid's coreutils
package (5.2.1-2), made from GNU coreutils 5.2.1.

Any ideas of what may be going on?