[  254.634525] SysRq : Show Blocked State
[  254.635041]   task                        PC stack   pid father
[  254.635304] kworker/0:2     D ffff88013fc145c0     0    83      2 0x00000000
[  254.635304] Workqueue: xfs-log/vdb xfs_log_worker [xfs]
[  254.635304]  ffff880136bdfa58 0000000000000046 ffff880136bdffd8 00000000000145c0
[  254.635304]  ffff880136bdffd8 00000000000145c0 ffff880136ad8000 ffff88013fc14e88
[  254.635304]  ffff880037bd4380 ffff880037bc5068 ffff880037bd43b0 ffff880037bd4380
[  254.635304] Call Trace:
[  254.635304]  [<ffffffff815e797d>] io_schedule+0x9d/0x140
[  254.635304]  [<ffffffff812921d5>] get_request+0x1b5/0x790
[  254.635304]  [<ffffffff81086ab0>] ? wake_up_bit+0x30/0x30
[  254.635304]  [<ffffffff81294236>] blk_queue_bio+0x96/0x390
[  254.635304]  [<ffffffff812904e2>] generic_make_request+0xe2/0x130
[  254.635304]  [<ffffffff812905a1>] submit_bio+0x71/0x150
[  254.635304]  [<ffffffff811e72c8>] ? bio_alloc_bioset+0x1e8/0x2e0
[  254.635304]  [<ffffffffa03310bb>] _xfs_buf_ioapply+0x2bb/0x3d0 [xfs]
[  254.635304]  [<ffffffffa038d3ef>] ? xlog_bdstrat+0x1f/0x50 [xfs]
[  254.635304]  [<ffffffffa03328e6>] xfs_buf_iorequest+0x46/0xa0 [xfs]
[  254.635304]  [<ffffffffa038d3ef>] xlog_bdstrat+0x1f/0x50 [xfs]
[  254.635304]  [<ffffffffa038f135>] xlog_sync+0x265/0x450 [xfs]
[  254.635304]  [<ffffffffa038f3b2>] xlog_state_release_iclog+0x92/0xb0 [xfs]
[  254.635304]  [<ffffffffa039016a>] _xfs_log_force+0x15a/0x290 [xfs]
[  254.635304]  [<ffffffff810115d6>] ? __switch_to+0x136/0x490
[  254.635304]  [<ffffffffa03902c6>] xfs_log_force+0x26/0x80 [xfs]
[  254.635304]  [<ffffffffa0390344>] xfs_log_worker+0x24/0x50 [xfs]
[  254.635304]  [<ffffffff8107e02b>] process_one_work+0x17b/0x460
[  254.635304]  [<ffffffff8107edfb>] worker_thread+0x11b/0x400
[  254.635304]  [<ffffffff8107ece0>] ? rescuer_thread+0x400/0x400
[  254.635304]  [<ffffffff81085aef>] kthread+0xcf/0xe0
[  254.635304]  [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140
[  254.635304]  [<ffffffff815f24ec>] ret_from_fork+0x7c/0xb0
[  254.635304]  [<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140
[  254.635304] fio             D ffff88013fc145c0     0   772    770 0x00000000
[  254.635304]  ffff8800bba4b8c8 0000000000000082 ffff8800bba4bfd8 00000000000145c0
[  254.635304]  ffff8800bba4bfd8 00000000000145c0 ffff8801376ff1c0 ffff88013fc14e88
[  254.635304]  ffff880037bd4380 ffff880037baba90 ffff880037bd43b0 ffff880037bd4380
[  254.635304] Call Trace:
[  254.635304]  [<ffffffff815e797d>] io_schedule+0x9d/0x140
[  254.635304]  [<ffffffff812921d5>] get_request+0x1b5/0x790
[  254.635304]  [<ffffffff81086ab0>] ? wake_up_bit+0x30/0x30
[  254.635304]  [<ffffffff81294236>] blk_queue_bio+0x96/0x390
[  254.635304]  [<ffffffff812904e2>] generic_make_request+0xe2/0x130
[  254.635304]  [<ffffffff812905a1>] submit_bio+0x71/0x150
[  254.635304]  [<ffffffff811ed26c>] do_blockdev_direct_IO+0x14bc/0x2620
[  254.635304]  [<ffffffffa032bc30>] ? xfs_get_blocks+0x20/0x20 [xfs]
[  254.635304]  [<ffffffff811ee425>] __blockdev_direct_IO+0x55/0x60
[  254.635304]  [<ffffffffa032bc30>] ? xfs_get_blocks+0x20/0x20 [xfs]
[  254.635304]  [<ffffffffa032aaec>] xfs_vm_direct_IO+0x15c/0x180 [xfs]
[  254.635304]  [<ffffffffa032bc30>] ? xfs_get_blocks+0x20/0x20 [xfs]
[  254.635304]  [<ffffffff81143563>] generic_file_aio_read+0x6d3/0x750
[  254.635304]  [<ffffffff810b69c8>] ? ktime_get_ts+0x48/0xe0
[  254.635304]  [<ffffffff811030cf>] ? delayacct_end+0x8f/0xb0
[  254.635304]  [<ffffffff815e6a32>] ? down_read+0x12/0x30
[  254.635304]  [<ffffffffa0337224>] xfs_file_aio_read+0x154/0x2e0 [xfs]
[  254.635304]  [<ffffffffa03370d0>] ? xfs_file_splice_read+0x140/0x140 [xfs]
[  254.635304]  [<ffffffff811fd6a8>] do_io_submit+0x3b8/0x840
[  254.635304]  [<ffffffff811fdb40>] SyS_io_submit+0x10/0x20
[  254.635304]  [<ffffffff815f2599>] system_call_fastpath+0x16/0x1b