How to make nginx fail if it can't write to cache dir.

[unikron]

The error on a base dir is critical to all cache requests, so no request
will succeed.
I know I can write a script to monitor it, but it seems like the wrong
approach.
I would like to have the option for nginx to stop if it can't do the job as
should, But I guess that if no one answered with that kind of solution, it
doesn't exist in nginx.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,293477,293533#msg-293533