On Wed, 2024-01-31 at 14:36 +0100, Christian Brauner wrote: > * If we have a session about this at LSFMM and I want to see a POC of > tracefs and eventfs built on top of kernfs. I'm tired of talking > about > a private implementation of functionality that already exists. > Otherwise, this is just wasting everyone's time and eventfs as it > is > will not become common infrastructure. Note: I asked for this to be updated to be a "how do we prevent this happening again" type session. I believe you took this as "the VFS is insufficiently documented" but that wasn't my intent. There's clearly something missing that should give people looking to do filesystems like this a clear direction on how to start, where to look and what vfs properties are required, which properties break some tools if not implemented (which may or may not be important to the use case) and which are nice to have. When I did shiftfs, my biggest problem was actually getting configfs to work for it due to being unable to operate without a superblock, so learning all the VFS intricacies came in second to that. I did think at the time I should do a talk more focussed on what I learned about the basics of the VFS for psuedo filesystems, but that got lost in the need to push shiftfs itself. After that most of my subsequent talks were about extending configfs because that was the area I had the most problems ... James
