I just compiled and booted bk head (2.6.1-rc1+), changeset key
ak@muc.de[torvalds]|ChangeSet|20040101194103|59346
and got this, probably when running /etc/init.d/nfs-kernel-server stop,
but I'm not sure about that. It's a Debian box.

nfsd: last server has exited
nfsd: unexporting all filesystems
Debug: sleeping function called from invalid context at mm/slab.c:1856
in_atomic():1, irqs_disabled():0
Call Trace:
  [<c011e71b>] __might_sleep+0xab/0xd0
  [<c010b8d9>] do_IRQ+0x109/0x140
  [<c01409b5>] kmem_cache_alloc+0x65/0x70
  [<c0198e4e>] new_handle+0x1e/0x50
  [<c0198f03>] journal_start+0x83/0xd0
  [<c018bc83>] start_transaction+0x23/0x60
  [<c018bd50>] ext3_delete_inode+0x0/0x100
  [<c018bd77>] ext3_delete_inode+0x27/0x100
  [<c018bd50>] ext3_delete_inode+0x0/0x100
  [<c016dcfc>] generic_delete_inode+0x6c/0x110
  [<c018bd34>] ext3_put_inode+0x14/0x30
  [<c016df73>] iput+0x63/0x80
  [<c016af7c>] dput+0xfc/0x210
  [<c020b162>] svc_export_put+0x42/0x80
  [<c04605e4>] cache_clean+0x144/0x220
  [<c0460725>] cache_flush+0x15/0x50
  [<c020cd1c>] nfsd_export_flush+0x4c/0x70
  [<c0203ead>] nfsd+0x31d/0x3a0
  [<c0203b90>] nfsd+0x0/0x3a0
  [<c01072a9>] kernel_thread_helper+0x5/0xc


Config and dmesg attached. Yes, I know about the hdg errors; that's
a "junk" disk not used for the actual OS files.