RHEL7: Soft lockup occurs while device is umounted.

Issue

[34511.019780] NMI watchdog: BUG: soft lockup - CPU#10 stuck for 22s! [umount:12332]
[34511.020056] CPU: 10 PID: 12332 Comm: umount Kdump: loaded Not tainted 3.10.0-1062.1.2.el7.x86_64 #1
[34511.020058] Hardware name: Cisco Systems Inc UCSC-C460-M4/UCSC-C460-M4, BIOS C460M4.3.0.4g.0.0508190204 05/08/2019
[34511.020059] task: ffff9ac97997c1c0 ti: ffff9acac63f8000 task.ti: ffff9acac63f8000
[34511.020061] RIP: 0010:[<ffffffff96381b20>]  [<ffffffff96381b20>] _raw_spin_lock+0x10/0x30
[34511.020071] RSP: 0018:ffff9acac63fbde0  EFLAGS: 00000246
[34511.020072] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000020090
[34511.020074] RDX: 0000000000000001 RSI: 0000000000000018 RDI: ffff9a932aa0d088
[34511.020075] RBP: ffff9acac63fbe48 R08: ffff9ab846403740 R09: 00000001802a0029
[34511.020076] R10: 0000000000000001 R11: ffff9ab846403740 R12: ffff9a8d19fc08d0
[34511.020077] R13: 00000001802a0029 R14: 0000000000000000 R15: 0000000000000000
[34511.020079] FS:  00007f3e3b342880(0000) GS:ffff9a787fc80000(0000) knlGS:0000000000000000
[34511.020080] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[34511.020081] CR2: 0000000000f774a8 CR3: 00000028295f4000 CR4: 00000000001607e0
[34511.020083] Call Trace:
[34511.020095]  [<ffffffff95e90d00>] ? fsnotify_unmount_inodes+0x90/0x1d0
[34511.020102]  [<ffffffff95e61eb0>] ? shrink_dcache_for_umount_subtree+0x160/0x1e0
[34511.020109]  [<ffffffff95e4b107>] generic_shutdown_super+0x37/0x100
[34511.020112]  [<ffffffff95e4b5b7>] kill_block_super+0x27/0x70
[34511.020115]  [<ffffffff95e4b91e>] deactivate_locked_super+0x4e/0x70
[34511.020117]  [<ffffffff95e4c0a6>] deactivate_super+0x46/0x60
[34511.020121]  [<ffffffff95e6abff>] cleanup_mnt+0x3f/0x80
[34511.020122]  [<ffffffff95e6ac92>] __cleanup_mnt+0x12/0x20
[34511.020131]  [<ffffffff95cc1c0b>] task_work_run+0xbb/0xe0
[34511.020137]  [<ffffffff95c2cc65>] do_notify_resume+0xa5/0xc0
[34511.020141]  [<ffffffff9638d23b>] int_signal+0x12/0x17
[34511.020146] Code: 44 00 00 85 d2 74 e4 0f 1f 40 00 eb ed 66 0f 1f 44 00 00 b8 01 00 00 00 5d c3 90 0f 1f 44 00 00 31 c0 ba 01 00 00 00 f0 0f b1 17 <85> c0 75 01 c3 55 89 c6 48 89 e5 e8 8a 18 ff ff 5d c3 0f 1f 40