Comment 17 for bug 1767738

running with 4.17 rc2 mainline gives me this callstack

[Apr29 12:17] usb 4-2: reset SuperSpeed USB device number 2 using xhci_hcd
[Apr29 12:19] INFO: task pool:3929 blocked for more than 120 seconds.
[ +0.000005] Not tainted 4.17.0-041700rc2-generic #201804230622
[ +0.000001] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ +0.000002] pool D 0 3929 1 0x00000000
[ +0.000004] Call Trace:
[ +0.000008] __schedule+0x28e/0x830
[ +0.000005] ? enqueue_task_fair+0xdc/0x850
[ +0.000005] ? get_work_pool+0x40/0x40
[ +0.000003] schedule+0x2c/0x80
[ +0.000004] schedule_timeout+0x1db/0x360
[ +0.000004] ? ttwu_do_activate+0x77/0x80
[ +0.000003] ? get_work_pool+0x40/0x40
[ +0.000002] wait_for_completion+0xba/0x140
[ +0.000003] ? wake_up_q+0x80/0x80
[ +0.000004] flush_work+0x127/0x1e0
[ +0.000003] ? worker_detach_from_pool+0xa0/0xa0
[ +0.000003] __cancel_work_timer+0x131/0x1b0
[ +0.000005] ? exact_lock+0x11/0x20
[ +0.000003] cancel_delayed_work_sync+0x13/0x20
[ +0.000003] disk_block_events+0x78/0x80
[ +0.000005] __blkdev_get+0x73/0x510
[ +0.000005] blkdev_get+0x22e/0x340
[ +0.000005] ? mntput+0x24/0x40
[ +0.000003] ? path_put+0x1e/0x30
[ +0.000003] blkdev_get_by_path+0x53/0x90
[ +0.000003] mount_bdev+0x44/0x1b0
[ +0.000004] ? hfsplus_iget+0x210/0x210 [hfsplus]
[ +0.000004] hfsplus_mount+0x15/0x20 [hfsplus]
[ +0.000002] mount_fs+0x37/0x150
[ +0.000004] vfs_kern_mount.part.25+0x5d/0x110
[ +0.000002] do_mount+0x5ed/0xce0
[ +0.000002] ? copy_mount_options+0x2c/0x220
[ +0.000003] ksys_mount+0x98/0xe0
[ +0.000002] __x64_sys_mount+0x25/0x30
[ +0.000004] do_syscall_64+0x5a/0x120
[ +0.000003] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ +0.000003] RIP: 0033:0x7f5aa3c653ca
[ +0.000002] RSP: 002b:00007f5a8f1fb2a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
[ +0.000003] RAX: ffffffffffffffda RBX: 00007f5a84008bb0 RCX: 00007f5aa3c653ca
[ +0.000001] RDX: 00007f5a84008520 RSI: 00007f5a84008d90 RDI: 00007f5a84008540
[ +0.000002] RBP: 0000000000000000 R08: 00007f5a84008dc0 R09: 00007f5a8400864f
[ +0.000002] R10: 00000000c0ed0006 R11: 0000000000000202 R12: 00007f5a84008540
[ +0.000001] R13: 00007f5a84008520 R14: 0000000000000000 R15: 00007f5aa55c88a4

i suspect it's related to the hfsplus partition that's on the harddrive