jul 14 21:49:11 mybox kernel: INFO: task kworker/u8:3:121 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: kworker/u8:3    D 0000000000000000     0   121      2 0x00000000
jul 14 21:49:11 mybox kernel: Workqueue: writeback bdi_writeback_workfn (flush-btrfs-2)
jul 14 21:49:11 mybox kernel:  ffff88007feaf9b8 0000000000000046 ffff880212e065e0 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88007feaffd8 0000000000014700 ffff880212e065e0 ffffffffa007c692
jul 14 21:49:11 mybox kernel:  0000000000000000 ffffffff00000050 ffff88007feafa34 ffff88007feaf938
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffffa007c692>] ? run_delalloc_range+0x192/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8101ce09>] ? read_tsc+0x9/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff810d49d8>] ? ktime_get_ts+0x48/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff810fed95>] ? delayacct_end+0x95/0xc0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f9e8>] __lock_page+0x78/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff810b1c80>] ? autoremove_wake_function+0x40/0x40
jul 14 21:49:11 mybox kernel:  [<ffffffffa0094c98>] extent_write_cache_pages.isra.28.constprop.45+0x258/0x3a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa009620c>] extent_writepages+0x5c/0x90 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00789d0>] ? __btrfs_submit_bio_start_direct_io+0x40/0x40 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task kworker/u8:3:121 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: kworker/u8:3    D 0000000000000000     0   121      2 0x00000000
jul 14 21:49:11 mybox kernel: Workqueue: writeback bdi_writeback_workfn (flush-btrfs-2)
jul 14 21:49:11 mybox kernel:  ffff88007feaf9b8 0000000000000046 ffff880212e065e0 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88007feaffd8 0000000000014700 ffff880212e065e0 ffffffffa007c692
jul 14 21:49:11 mybox kernel:  0000000000000000 ffffffff00000050 ffff88007feafa34 ffff88007feaf938
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffffa007c692>] ? run_delalloc_range+0x192/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8101ce09>] ? read_tsc+0x9/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff810d49d8>] ? ktime_get_ts+0x48/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff810fed95>] ? delayacct_end+0x95/0xc0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f9e8>] __lock_page+0x78/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff810b1c80>] ? autoremove_wake_function+0x40/0x40
jul 14 21:49:11 mybox kernel:  [<ffffffffa0094c98>] extent_write_cache_pages.isra.28.constprop.45+0x258/0x3a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa009620c>] extent_writepages+0x5c/0x90 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00789d0>] ? __btrfs_submit_bio_start_direct_io+0x40/0x40 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00776e8>] btrfs_writepages+0x28/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8114d1de>] do_writepages+0x1e/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff811df3a0>] __writeback_single_inode+0x40/0x2b0
jul 14 21:49:11 mybox kernel:  [<ffffffff811e08aa>] writeback_sb_inodes+0x26a/0x430
jul 14 21:49:11 mybox kernel:  [<ffffffff811e0b0f>] __writeback_inodes_wb+0x9f/0xd0
jul 14 21:49:11 mybox kernel:  [<ffffffff811e0d6b>] wb_writeback+0x22b/0x360
jul 14 21:49:11 mybox kernel:  [<ffffffff8114bec0>] ? bdi_dirty_limit+0x40/0xe0
jul 14 21:49:11 mybox kernel:  [<ffffffff811e11ec>] bdi_writeback_workfn+0x1ec/0x4c0
jul 14 21:49:11 mybox kernel:  [<ffffffff810861d8>] process_one_work+0x168/0x450
jul 14 21:49:11 mybox kernel:  [<ffffffff81086c32>] worker_thread+0x132/0x3e0
jul 14 21:49:11 mybox kernel:  [<ffffffff81086b00>] ? manage_workers.isra.23+0x2d0/0x2d0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d43a>] kthread+0xea/0x100
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task btrfs-transacti:436 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: btrfs-transacti D 0000000000000001     0   436      2 0x00000000
jul 14 21:49:11 mybox kernel:  ffff88020d89fc50 0000000000000046 ffff880212050000 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88020d89ffd8 0000000000014700 ffff880212050000 ffff88020d89fbc0
jul 14 21:49:11 mybox kernel:  ffffffff810a902e 0000000000014700 0000000000000000 ffff880212e051e8
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffff810a902e>] ? enqueue_entity+0x24e/0xaa0
jul 14 21:49:11 mybox kernel:  [<ffffffff810a998d>] ? enqueue_task_fair+0x10d/0x5b0
jul 14 21:49:11 mybox kernel:  [<ffffffff810a15f5>] ? sched_clock_cpu+0xb5/0xe0
jul 14 21:49:11 mybox kernel:  [<ffffffff8109b527>] ? check_preempt_curr+0x57/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff81509199>] schedule_timeout+0x1b9/0x240
jul 14 21:49:11 mybox kernel:  [<ffffffff8109e133>] ? wake_up_process+0x23/0x50
jul 14 21:49:11 mybox kernel:  [<ffffffff8150aa6f>] wait_for_common+0xcf/0x190
jul 14 21:49:11 mybox kernel:  [<ffffffff8109e160>] ? wake_up_process+0x50/0x50
jul 14 21:49:11 mybox kernel:  [<ffffffff8150ab4d>] wait_for_completion+0x1d/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffffa0084df6>] btrfs_wait_and_free_delalloc_work+0x16/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa008f128>] btrfs_run_ordered_operations+0x1f8/0x2e0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0074546>] btrfs_commit_transaction+0x36/0xa20 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0070475>] transaction_kthread+0x1e5/0x250 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0070290>] ? btrfs_cleanup_transaction+0x5a0/0x5a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d43a>] kthread+0xea/0x100
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task kworker/u8:12:882 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: kworker/u8:12   D 0000000000000000     0   882      2 0x00000000
jul 14 21:49:11 mybox kernel: Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
jul 14 21:49:11 mybox kernel:  ffff8801f7c23b48 0000000000000046 ffff880204991e90 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff8801f7c23fd8 0000000000014700 ffff880204991e90 ffff8802133ef740
jul 14 21:49:11 mybox kernel:  0000000000014700 0000000000014700 0000000000000000 ffff8802133ef6d8
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f9e8>] __lock_page+0x78/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff810b1c80>] ? autoremove_wake_function+0x40/0x40
jul 14 21:49:11 mybox kernel:  [<ffffffffa0094c98>] extent_write_cache_pages.isra.28.constprop.45+0x258/0x3a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff810a902e>] ? enqueue_entity+0x24e/0xaa0
jul 14 21:49:11 mybox kernel:  [<ffffffffa009620c>] extent_writepages+0x5c/0x90 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00789d0>] ? __btrfs_submit_bio_start_direct_io+0x40/0x40 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00776e8>] btrfs_writepages+0x28/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8114d1de>] do_writepages+0x1e/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff8114139d>] __filemap_fdatawrite_range+0x5d/0x80
jul 14 21:49:11 mybox kernel:  [<ffffffff8114140c>] filemap_flush+0x1c/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffffa007a46a>] btrfs_run_delalloc_work+0x5a/0xa0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00a4a77>] normal_work_helper+0x77/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff810861d8>] process_one_work+0x168/0x450
jul 14 21:49:11 mybox kernel:  [<ffffffff81086c32>] worker_thread+0x132/0x3e0
jul 14 21:49:11 mybox kernel:  [<ffffffff81086b00>] ? manage_workers.isra.23+0x2d0/0x2d0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d43a>] kthread+0xea/0x100
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task thunderbird:1015 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: thunderbird     D 0000000000000002     0  1015    952 0x00000004
jul 14 21:49:11 mybox kernel:  ffff88020da3bc48 0000000000000086 ffff880204abd180 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88020da3bfd8 0000000000014700 ffff880204abd180 ffff88020da3bc10
jul 14 21:49:11 mybox kernel:  ffffffffa007c692 0000000000000000 ffffffff00000050 ffff88020da3bccc
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffffa007c692>] ? run_delalloc_range+0x192/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Jul 14 21:49:11 mybox kernel: btrfs-transacti D 0000000000000001     0   436      2 0x00000000
jul 14 21:49:11 mybox kernel:  ffff88020d89fc50 0000000000000046 ffff880212050000 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88020d89ffd8 0000000000014700 ffff880212050000 ffff88020d89fbc0
jul 14 21:49:11 mybox kernel:  ffffffff810a902e 0000000000014700 0000000000000000 ffff880212e051e8
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffff810a902e>] ? enqueue_entity+0x24e/0xaa0
jul 14 21:49:11 mybox kernel:  [<ffffffff810a998d>] ? enqueue_task_fair+0x10d/0x5b0
jul 14 21:49:11 mybox kernel:  [<ffffffff810a15f5>] ? sched_clock_cpu+0xb5/0xe0
jul 14 21:49:11 mybox kernel:  [<ffffffff8109b527>] ? check_preempt_curr+0x57/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff81509199>] schedule_timeout+0x1b9/0x240
jul 14 21:49:11 mybox kernel:  [<ffffffff8109e133>] ? wake_up_process+0x23/0x50
jul 14 21:49:11 mybox kernel:  [<ffffffff8150aa6f>] wait_for_common+0xcf/0x190
jul 14 21:49:11 mybox kernel:  [<ffffffff8109e160>] ? wake_up_process+0x50/0x50
jul 14 21:49:11 mybox kernel:  [<ffffffff8150ab4d>] wait_for_completion+0x1d/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffffa0084df6>] btrfs_wait_and_free_delalloc_work+0x16/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa008f128>] btrfs_run_ordered_operations+0x1f8/0x2e0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0074546>] btrfs_commit_transaction+0x36/0xa20 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0070475>] transaction_kthread+0x1e5/0x250 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0070290>] ? btrfs_cleanup_transaction+0x5a0/0x5a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d43a>] kthread+0xea/0x100
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task kworker/u8:12:882 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: kworker/u8:12   D 0000000000000000     0   882      2 0x00000000
jul 14 21:49:11 mybox kernel: Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
jul 14 21:49:11 mybox kernel:  ffff8801f7c23b48 0000000000000046 ffff880204991e90 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff8801f7c23fd8 0000000000014700 ffff880204991e90 ffff8802133ef740
jul 14 21:49:11 mybox kernel:  0000000000014700 0000000000014700 0000000000000000 ffff8802133ef6d8
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f9e8>] __lock_page+0x78/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff810b1c80>] ? autoremove_wake_function+0x40/0x40
jul 14 21:49:11 mybox kernel:  [<ffffffffa0094c98>] extent_write_cache_pages.isra.28.constprop.45+0x258/0x3a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff810a902e>] ? enqueue_entity+0x24e/0xaa0
jul 14 21:49:11 mybox kernel:  [<ffffffffa009620c>] extent_writepages+0x5c/0x90 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00789d0>] ? __btrfs_submit_bio_start_direct_io+0x40/0x40 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00776e8>] btrfs_writepages+0x28/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8114d1de>] do_writepages+0x1e/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff8114139d>] __filemap_fdatawrite_range+0x5d/0x80
jul 14 21:49:11 mybox kernel:  [<ffffffff8114140c>] filemap_flush+0x1c/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffffa007a46a>] btrfs_run_delalloc_work+0x5a/0xa0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00a4a77>] normal_work_helper+0x77/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff810861d8>] process_one_work+0x168/0x450
jul 14 21:49:11 mybox kernel:  [<ffffffff81086c32>] worker_thread+0x132/0x3e0
jul 14 21:49:11 mybox kernel:  [<ffffffff81086b00>] ? manage_workers.isra.23+0x2d0/0x2d0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d43a>] kthread+0xea/0x100
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel:  [<ffffffff81515efc>] ret_from_fork+0x7c/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8108d350>] ? kthread_create_on_node+0x1b0/0x1b0
jul 14 21:49:11 mybox kernel: INFO: task thunderbird:1015 blocked for more than 120 seconds.
jul 14 21:49:11 mybox kernel:       Not tainted 3.15.5-1-ARCH #1
jul 14 21:49:11 mybox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
jul 14 21:49:11 mybox kernel: thunderbird     D 0000000000000002     0  1015    952 0x00000004
jul 14 21:49:11 mybox kernel:  ffff88020da3bc48 0000000000000086 ffff880204abd180 0000000000014700
jul 14 21:49:11 mybox kernel:  ffff88020da3bfd8 0000000000014700 ffff880204abd180 ffff88020da3bc10
jul 14 21:49:11 mybox kernel:  ffffffffa007c692 0000000000000000 ffffffff00000050 ffff88020da3bccc
jul 14 21:49:11 mybox kernel: Call Trace:
jul 14 21:49:11 mybox kernel:  [<ffffffffa007c692>] ? run_delalloc_range+0x192/0x350 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f880>] ? filemap_fdatawait+0x30/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff81509fa9>] schedule+0x29/0x70
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a294>] io_schedule+0x94/0xf0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f88e>] sleep_on_page+0xe/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff8150a788>] __wait_on_bit_lock+0x48/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff8113f9e8>] __lock_page+0x78/0x90
jul 14 21:49:11 mybox kernel:  [<ffffffff810b1c80>] ? autoremove_wake_function+0x40/0x40
jul 14 21:49:11 mybox kernel:  [<ffffffffa009077e>] ? flush_write_bio+0xe/0x10 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa0094c98>] extent_write_cache_pages.isra.28.constprop.45+0x258/0x3a0 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa009620c>] extent_writepages+0x5c/0x90 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00789d0>] ? __btrfs_submit_bio_start_direct_io+0x40/0x40 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffffa00776e8>] btrfs_writepages+0x28/0x30 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff8114d1de>] do_writepages+0x1e/0x30
jul 14 21:49:11 mybox kernel:  [<ffffffff8114139d>] __filemap_fdatawrite_range+0x5d/0x80
jul 14 21:49:11 mybox kernel:  [<ffffffff81141483>] filemap_fdatawrite_range+0x13/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffffa00857fd>] btrfs_sync_file+0x5d/0x310 [btrfs]
jul 14 21:49:11 mybox kernel:  [<ffffffff811d1d8e>] ? __fget+0x6e/0xb0
jul 14 21:49:11 mybox kernel:  [<ffffffff811e508e>] do_fsync+0x4e/0x80
jul 14 21:49:11 mybox kernel:  [<ffffffff811e5340>] SyS_fsync+0x10/0x20
jul 14 21:49:11 mybox kernel:  [<ffffffff81515fa9>] system_call_fastpath+0x16/0x1b