System hang due to swap deadlock around plugged I/O

Issue

• System hang due to swap deadlock around plugged I/O:

Call Trace:
 __schedule+0x2d1/0x860
 ? cpumask_any_but+0x20/0x40
 ? wbt_exit+0x30/0x30
 ? __wbt_done+0x40/0x40
 schedule+0x35/0xa0
 io_schedule+0x12/0x40
 rq_qos_wait+0xb3/0x130
 ? karma_partition+0x1f0/0x1f0
 ? wbt_exit+0x30/0x30
 wbt_wait+0x96/0xc0
 __rq_qos_throttle+0x23/0x40
 blk_mq_make_request+0x131/0x5c0
 generic_make_request_no_check+0xe1/0x330
 ? get_swap_bio+0xf0/0xf0
 submit_bio+0x3c/0x160
 __swap_writepage+0x126/0x410
 ? __frontswap_store+0x6e/0x100
 pageout+0xf8/0x300
 shrink_page_list+0xa34/0xca0
 shrink_inactive_list+0x19e/0x3e0
 shrink_lruvec+0x474/0x6c0
 shrink_node+0x22e/0x700
 do_try_to_free_pages+0xc9/0x3e0
 try_to_free_mem_cgroup_pages+0xf8/0x200
 try_charge+0x236/0x670
 obj_cgroup_charge_pages+0x3f/0xe0
 __memcg_kmem_charge_page+0xd9/0x1c0
 __alloc_pages_nodemask+0x272/0x320
 kmalloc_large_node+0x3c/0xa0
 __kmalloc_node+0x23f/0x310
 kvmalloc_node+0x3e/0x70
 ? get_iowait_time.isra.4+0x40/0x40
 single_open_size+0x3c/0xb0
 proc_reg_open+0x71/0x140
 ? proc_put_link+0x10/0x10
 do_dentry_open+0x133/0x350
 path_openat+0x558/0x1500
 ? update_curr+0xe6/0x1c0
 do_filp_open+0x93/0x100
 ? mmput+0xf/0x130
 ? getname_flags+0x4a/0x1e0
 ? __check_object_size+0xac/0x173
 ? path_get+0x11/0x30
 ? __alloc_fd+0x44/0x150
 do_sys_openat2+0x211/0x2b0
 do_sys_open+0x4b/0x80
 do_syscall_64+0x5b/0x1b0
 entry_SYSCALL_64_after_hwframe+0x61/0xc6