WARNING: at fs/ext4/ext4_jbd2.c:50 __ext4_journal_start_sb+0x132/0x240()
Hardware name:         
Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod
Pid: 2406, comm: fstest Not tainted 3.8.0-rc3+ #101
Call Trace:
 [<ffffffff8106fb0d>] warn_slowpath_common+0xad/0xf0
 [<ffffffff813882a2>] ? ext4_ext_remove_space+0x62/0xb00
 [<ffffffff8106fb6a>] warn_slowpath_null+0x1a/0x20
 [<ffffffff8138a222>] __ext4_journal_start_sb+0x132/0x240
 [<ffffffff813882a2>] ext4_ext_remove_space+0x62/0xb00
 [<ffffffff813a5004>] ? ext4_es_remove_extent+0x134/0x150
 [<ffffffff813895cf>] ? ext4_ext_truncate+0x1ef/0x2c0
 [<ffffffff81389621>] ext4_ext_truncate+0x241/0x2c0
 [<ffffffff8133e338>] ext4_truncate+0x238/0x2a0
 [<ffffffff81342ae2>] ext4_setattr+0x232/0x900
 [<ffffffff81270e24>] notify_change+0x434/0x6a0
 [<ffffffff812411de>] do_truncate+0xae/0xe0
 [<ffffffff81259c7d>] do_last+0x80d/0xe20
 [<ffffffff8125b6c6>] path_openat+0x1d6/0x7f0
 [<ffffffff810ffb3d>] ? trace_hardirqs_off+0xd/0x10
 [<ffffffff810d0a55>] ? local_clock+0x165/0x170
 [<ffffffff8125bea9>] do_filp_open+0x49/0x120
 [<ffffffff81272c8e>] ? __alloc_fd+0x20e/0x240
 [<ffffffff81240254>] do_sys_open+0x264/0x320
 [<ffffffff81240351>] sys_open+0x21/0x30
 [<ffffffff818ff6d9>] system_call_fastpath+0x16/0x1b