Additional info:
reporter:       libreport-2.6.1
WARNING: CPU: 2 PID: 12337 at fs/fs-writeback.c:2079 __mark_inode_dirty+0x238/0x300()
bdi-block not registered
Modules linked in: uas usb_storage fuse ccm xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_broute bridge ebtable_nat ebtable_filter ebtables ip6table_security ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_raw ip6table_filter ip6_tables iptable_security iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_raw bnep intel_rapl iosf_mbi vfat fat x86_pkg_temp_thermal coretemp kvm_intel snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic iTCO_wdt arc4 kvm iTCO_vendor_support snd_hda_intel snd_hda_codec snd_hda_core iwldvm snd_hwdep crct10dif_pclmul crc32_pclmul snd_seq crc32c_intel mac80211
 btusb btrtl ghash_clmulni_intel uvcvideo btbcm btintel bluetooth snd_seq_device videobuf2_vmalloc videobuf2_core videobuf2_memops iwlwifi v4l2_common videodev snd_pcm cfg80211 media thinkpad_acpi snd_timer snd tpm_tis wmi soundcore rfkill mei_me tpm shpchp mei lpc_ich i2c_i801 nfsd auth_rpcgss nfs_acl lockd grace sunrpc 8021q garp stp llc mrp i915 i2c_algo_bit drm_kms_helper serio_raw sdhci_pci e1000e drm sdhci mmc_core ptp pps_core video
CPU: 2 PID: 12337 Comm: umount Not tainted 4.2.0-0.rc2.git1.1.fc24.x86_64 #1
Hardware name: LENOVO 23205NG/23205NG, BIOS G2ETA4WW (2.64 ) 04/09/2015
 0000000000000000 00000000ad3a60c6 ffff88013b9cfc78 ffffffff8176d900
 0000000000000000 ffff88013b9cfcd0 ffff88013b9cfcb8 ffffffff8109c7e6
 ffff880202e610c0 0000000000000000 ffff8802110e8a80 ffff880215428df0
Call Trace:
 [<ffffffff8176d900>] dump_stack+0x45/0x57
 [<ffffffff8109c7e6>] warn_slowpath_common+0x86/0xc0
 [<ffffffff8109c875>] warn_slowpath_fmt+0x55/0x70
 [<ffffffff81244bf1>] ? locked_inode_to_wb_and_lock_list+0x51/0xc0
 [<ffffffff812456f8>] __mark_inode_dirty+0x238/0x300
 [<ffffffff8124d1ee>] mark_buffer_dirty+0x8e/0x100
 [<ffffffff812c18fb>] ext4_commit_super+0x16b/0x210
 [<ffffffff812c26b2>] ext4_put_super+0xe2/0x350
 [<ffffffff8121b416>] generic_shutdown_super+0x76/0xf0
 [<ffffffff8121b787>] kill_block_super+0x27/0x70
 [<ffffffff8121bad3>] deactivate_locked_super+0x43/0x70
 [<ffffffff8121bf14>] deactivate_super+0x64/0x70
 [<ffffffff81238233>] cleanup_mnt+0x43/0x90
 [<ffffffff812382d2>] __cleanup_mnt+0x12/0x20
 [<ffffffff810b8e8b>] task_work_run+0x9b/0xb0
 [<ffffffff81014a6d>] do_notify_resume+0x8d/0x90
 [<ffffffff817741bc>] int_signal+0x12/0x17