White paper: Vendor Kernels, Bugs and Stability

Posted May 18, 2024 19:46 UTC (Sat) by NYKevin (subscriber, #129325)
In reply to: White paper: Vendor Kernels, Bugs and Stability by adobriyan
Parent article: White paper: Vendor Kernels, Bugs and Stability

There are a couple of problems with this idea:

0. /etc/fstab is a configuration file. It's not the kernel's place to modify config files (software like Puppet or Ansible will change it back).
1. Assuming you meant /etc/mtab, that's (usually) managed in userspace. It's also none of the kernel's business.
2. Assuming you meant /proc/mounts, there might be some userspace software that parses it and compares it against what it "should" look like, and misbehaves if a random mount option is missing (e.g. gets stuck in a hot loop of repeatedly remounting the device with the "correct" mount options, fires an alert and tells the sysadmin to come running, etc.).

(No, paging the sysadmin at 3 AM is not a reasonable response to this situation. Nothing is actually broken!)

White paper: Vendor Kernels, Bugs and Stability

Posted May 18, 2024 20:29 UTC (Sat) by adobriyan (subscriber, #30858) [Link] (1 responses)

> It's not the kernel's place to modify config files

I know, relax :-) it was a joke.

White paper: Vendor Kernels, Bugs and Stability

Posted May 19, 2024 4:01 UTC (Sun) by wtarreau (subscriber, #51152) [Link]

Even as a joke, please do not throw ideas like this, there's always a risk someone finds them great and starts to try to implement them and advocate them around.

White paper: Vendor Kernels, Bugs and Stability

Posted May 19, 2024 9:07 UTC (Sun) by smurf (subscriber, #17840) [Link] (1 responses)

Umm, /etc/mtab isn't managed in userspace. Or rather, it hasn't been for ages. These days it's a symlink to /proc/self/mounts.

White paper: Vendor Kernels, Bugs and Stability

Posted May 20, 2024 17:35 UTC (Mon) by NYKevin (subscriber, #129325) [Link]

It was... like 10-15 years ago when I cut my teeth on this stuff. But nowadays, we have software for everything, so I haven't actually played with low-level mounting etc. in a long time.

Which is also, sort of, the point I'm trying to make here. It is no longer accurate to divide userspace into "applications" and "stuff the sysadmin manually fiddles with." Sysadmins are not manually fiddling with mount options etc. these days. That's all managed by some other piece of software that isn't "the application," but can still break and cause problems all the same. E.g. k8s, Puppet, Docker, etc.