Additional info:
reporter:       libreport-2.2.3
WARNING: CPU: 0 PID: 3447 at fs/ext4/ext4_jbd2.c:260 __ext4_handle_dirty_metadata+0x1b2/0x200()
Modules linked in: tcp_lp rfcomm fuse ccm ip6t_rpfilter ip6t_REJECT xt_conntrack bnep ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw vfat fat rtsx_usb_ms memstick rtsx_usb_sdmmc mmc_core arc4 rtsx_usb iwldvm snd_hda_codec_hdmi mac80211 uvcvideo x86_pkg_temp_thermal snd_hda_codec_realtek r8169 coretemp snd_hda_codec_generic iTCO_wdt kvm_intel videobuf2_vmalloc btusb iTCO_vendor_support snd_hda_intel mii snd_hda_controller bluetooth kvm crct10dif_pclmul crc32_pclmul videobuf2_memops videobuf2_core lpc_ich mei_me mei v4l2_common
videodev iwlwifi joydev cfg80211 shpchp crc32c_intel ghash_clmulni_intel snd_hda_codec ideapad_laptop i2c_i801 media serio_raw mfd_core snd_hwdep wmi sparse_keymap snd_seq rfkill snd_seq_device nfsd snd_pcm snd_timer snd auth_rpcgss soundcore nfs_acl lockd sunrpc binfmt_misc i915 i2c_algo_bit drm_kms_helper drm video
CPU: 0 PID: 3447 Comm: URL Classifier Not tainted 3.17.3-200.fc20.x86_64 #1
Hardware name: LENOVO IdeaPad Z580    /Lenovo          , BIOS 5FCN95WW 12/25/2012
0000000000000000 00000000e6bc1118 ffff8801acf3ba78 ffffffff81728acc
0000000000000000 ffff8801acf3bab0 ffffffff81094e6d ffff88021323cbc8
0000000000000000 ffff880210741570 ffffffff81840970 0000000000000b9a
Call Trace:
[<ffffffff81728acc>] dump_stack+0x45/0x56
[<ffffffff81094e6d>] warn_slowpath_common+0x7d/0xa0
[<ffffffff81094f9a>] warn_slowpath_null+0x1a/0x20
[<ffffffff812ba522>] __ext4_handle_dirty_metadata+0x1b2/0x200
[<ffffffff812d48d2>] ? jbd2_journal_get_write_access+0x32/0x40
[<ffffffff812c1206>] ext4_mb_mark_diskspace_used+0x2c6/0x4f0
[<ffffffff812c279d>] ext4_mb_new_blocks+0x2ad/0x550
[<ffffffff812b345d>] ? ext4_ext_find_extent+0x23d/0x2d0
[<ffffffff812b785a>] ext4_ext_map_blocks+0x6ba/0x1160
[<ffffffff8128a5fd>] ext4_map_blocks+0x16d/0x560
[<ffffffff8128da86>] ext4_writepages+0x666/0xcd0
[<ffffffff8118d1bf>] ? __generic_file_write_iter+0x15f/0x350
[<ffffffff8120120e>] ? new_sync_write+0x8e/0xd0
[<ffffffff8119813e>] do_writepages+0x1e/0x40
[<ffffffff8118c76d>] __filemap_fdatawrite_range+0x5d/0x80
[<ffffffff8118c88a>] filemap_write_and_wait_range+0x2a/0x70
[<ffffffff8128520a>] ext4_sync_file+0xba/0x320
[<ffffffff81231641>] do_fsync+0x51/0x80
[<ffffffff81131436>] ? __audit_syscall_exit+0x1f6/0x2a0
[<ffffffff812318e0>] SyS_fsync+0x10/0x20
[<ffffffff817301a9>] system_call_fastpath+0x16/0x1b

Potential duplicate: bug 1154258