Exactly what userspace commands did you run with exactly what options? What is the architecture? (Arch & chunksize interact.)
You also need to say what userspace versions of lvm2 & device-mapper you are using - it's not necessarily a kernel bug.
There have been a lot of fixes to kernel device-mapper, including snapshots, since 2.6.15. So test against the latest upstream kernel and userspace packages if you can and see whether or not the problem has already been fixed there.
You need to improve your bug reporting skills:-)
Exactly what userspace commands did you run with exactly what options? What is the architecture? (Arch & chunksize interact.)
You also need to say what userspace versions of lvm2 & device-mapper you are using - it's not necessarily a kernel bug.
There have been a lot of fixes to kernel device-mapper, including snapshots, since 2.6.15. So test against the latest upstream kernel and userspace packages if you can and see whether or not the problem has already been fixed there.