Exploring building a tiny FUSE filesystem

The glibc test suite contains a few tiny FUSE file systems. For example, there is one that just happens to contain every file that mkstemp attempts to create, for a test that exercises the O_CREAT|O_EXCL failure path. Like the Rust fuser crate, it uses the kernel API directly. The tests are slightly brittle because sometimes we encounter a new LSM that triggers unexpected file system operations, but it's not too bad overall.

What I found funny when I discovered it is that you can create a thread in the same process that provides the FUSE file system implementation for this very process. It makes it much easier to write certain tests, especially debugging. We had to teach valgrind that more system calls effectively perform callbacks into the same process, but fortunately valgrind already had a FUSE_COMPATIBLE_MAY_BLOCK mechanism for that.

The older I get, the more I appreciate posts that are basically I wanted to understand X, so I built a tiny version of it.

I don't know why, but I really enjoy reading this kind of content. I admire the people who implement and maintain this system.

Kernel FUSE documentation is a dead link

Can someone tell me if this is LLM generated content or not? I tried to look for obvious signs but didn't notice anything.