Comment 4 for bug 1577792

There are a bunch of traces in the logs:

[52472.190933] Freezing user space processes ...
[52492.195179] Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0):
[52492.195506] fstrim D ffff880146613a98 0 28271 28270 0x00000004
[52492.195515] ffff880146613a98 ffff880146613a88 ffff88043bad9b80 ffff8803aa4bb700
[52492.195521] ffff880146614000 ffff88044dc96d00 7fffffffffffffff ffff8803aa4bb700
[52492.195527] 000000000245f288 ffff880146613ab0 ffffffff818203f5 0000000000000000
[52492.195532] Call Trace:
[52492.195546] [<ffffffff818203f5>] schedule+0x35/0x80
[52492.195553] [<ffffffff81823515>] schedule_timeout+0x1b5/0x270
[52492.195560] [<ffffffff8181f944>] io_schedule_timeout+0xa4/0x110
[52492.195566] [<ffffffff81821903>] wait_for_completion_io+0xb3/0x140
[52492.195572] [<ffffffff810abde0>] ? wake_up_q+0x70/0x70
[52492.195578] [<ffffffff813c2836>] blkdev_issue_discard+0x1f6/0x250
[52492.195586] [<ffffffff812d5aff>] ext4_trim_fs+0x49f/0xa20
[52492.195594] [<ffffffff812a11d9>] ext4_ioctl+0xdb9/0x1220
[52492.195600] [<ffffffff81211ae3>] ? cp_new_stat+0x153/0x180
[52492.195607] [<ffffffff81301028>] ecryptfs_unlocked_ioctl+0x48/0x80
[52492.195612] [<ffffffff812200ff>] do_vfs_ioctl+0x29f/0x490
[52492.195617] [<ffffffff81211c64>] ? SYSC_newfstat+0x34/0x60
[52492.195622] [<ffffffff81220369>] SyS_ioctl+0x79/0x90
[52492.195629] [<ffffffff818244f2>] entry_SYSCALL_64_fastpath+0x16/0x71