Ceph » Linux kernel client

I'm seeing this on the unstable branch:

[  443.860000] ------------[ cut here ]------------
[  443.860000] WARNING: at fs/fs-writeback.c:87 __mark_inode_dirty+0x114/0x1d6()
[  443.860000] Dirtiable inode bdi default != sb bdi (null)
[  443.860000] Modules linked in:
[  443.860000] Call Trace: 
[  443.860000] 76a69aa8:  [<6003029c>] warn_slowpath_common+0x5c/0x75
[  443.860000] 76a69ad8:  [<60090266>] filldir+0x0/0x120
[  443.860000] 76a69ae8:  [<6003040c>] warn_slowpath_fmt+0xa2/0xa4
[  443.860000] 76a69b18:  [<6012d87b>] ceph_readdir+0xba3/0x115d
[  443.860000] 76a69ba8:  [<60090266>] filldir+0x0/0x120
[  443.860000] 76a69bb8:  [<6022b023>] _raw_spin_lock+0x9/0xb
[  443.860000] 76a69bc8:  [<6009e1d1>] __mark_inode_dirty+0x114/0x1d6
[  443.860000] 76a69bf8:  [<600950cf>] touch_atime+0x100/0x123
[  443.860000] 76a69c48:  [<60090523>] vfs_readdir+0x80/0x9f
[  443.860000] 76a69c88:  [<600906b4>] sys_getdents+0x8f/0x11e
[  443.860000] 76a69cd8:  [<600170c5>] handle_syscall+0x59/0x70
[  443.860000] 76a69cf8:  [<600263c7>] userspace+0x3c0/0x465
[  443.860000] 76a69fc8:  [<60014b1b>] fork_handler+0x62/0x69
[  443.860000] 
[  443.860000] ---[ end trace 00c074596cf0ddd7 ]---