Additional info:
libreport version: 2.0.14
abrt_version:   2.0.13
cmdline:        BOOT_IMAGE=/vmlinuz-3.5.5-2.fc17.x86_64 root=UUID=af687f53-eaf4-4d46-b88a-eda148658671 ro rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True KEYTABLE=us rd.luks=0 LANG=en_US.UTF-8 rhgb quiet
kernel:         3.5.5-2.fc17.x86_64

kernel_tainted_long:
:Proprietary module has not been loaded.
:Modules from drivers/staging are loaded.

backtrace:
:WARNING: at fs/btrfs/extent_map.c:226 unpin_extent_cache+0x58/0xb0 [btrfs]()
:Hardware name:         
:Modules linked in: cpufreq_stats ip6table_filter ip6_tables vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) fuse tun sit tunnel4 bnep bluetooth rfkill nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack snd_hda_codec_hdmi snd_hda_codec_realtek uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev media coretemp kvm_intel kvm microcode serio_raw i2c_i801 snd_hda_intel lpc_ich mfd_core snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer snd e1000e mei soundcore uinput ata_generic pata_acpi btrfs libcrc32c zlib_deflate crc32c_intel ghash_clmulni_intel pata_marvell nouveau mxm_wmi wmi video i2c_algo_bit drm_kms_helper ttm drm i2c_core [last unloaded: ip6_tables]
:Pid: 1747, comm: btrfs-endio-wri Tainted: G         C O 3.5.5-2.fc17.x86_64 #1
:Call Trace:
: [<ffffffff8105864f>] warn_slowpath_common+0x7f/0xc0
: [<ffffffff810586aa>] warn_slowpath_null+0x1a/0x20
: [<ffffffffa01fcbc8>] unpin_extent_cache+0x58/0xb0 [btrfs]
: [<ffffffffa01f112b>] btrfs_finish_ordered_io+0x29b/0x410 [btrfs]
: [<ffffffffa01f12b5>] finish_ordered_fn+0x15/0x20 [btrfs]
: [<ffffffffa021bc46>] worker_loop+0x136/0x580 [btrfs]
: [<ffffffffa021bb10>] ? btrfs_queue_worker+0x300/0x300 [btrfs]
: [<ffffffff8107b183>] kthread+0x93/0xa0
: [<ffffffff816162a4>] kernel_thread_helper+0x4/0x10
: [<ffffffff8107b0f0>] ? kthread_freezable_should_stop+0x70/0x70
: [<ffffffff816162a0>] ? gs_change+0x13/0x13