Debug closures (bcache async widgits)

configname: CONFIG_DEBUG_CLOSURES

Linux Kernel Configuration
└─>Kernel hacking
└─>Debug kernel data structures
└─>Debug closures (bcache async widgits)
In linux kernel since version 4.14.330 (release Date: 2023-11-20)  
Keeps all active closures in a linked list and provides a debugfs
interface to list them, which makes it possible to see asynchronous
operations that get stuck.