fs_param_cb(9)

📦 version 7.3.1, in nixpkgs unstable

✨ fs_param_cb(9) ✨

okay so welcome to the Kernel API Manual bestie, today we're doing fs_param_cb — the general callback for a module/cmdline parameter that gets evaluated before the fs initcall level 🎀 like it's literally the early-bird special of kernel params, and honestly? iconic.

🌸 NAME 🌸

fs_param_cb — general callback for a module/cmdline parameter to be evaluated before fs initcall level 💅

🦋 SYNOPSIS 🦋

fs_param_cb (name , ops , arg , perm );

no cap, that's the whole vibe ✨

💖 ARGUMENTS 💖

  • name — a valid C identifier which is the parameter name. yes bestie it literally has to be a valid C identifier, don't come at me with spaces 🙈
  • ops — the set & get operations for this parameter. this is where the actual doing stuff lives 👑
  • arg — args for ops. it's giving "pass it along" energy 🫶
  • perm — visibility in sysfs. who gets to peek 👀

🔥 DESCRIPTION 🔥

The ops can have NULL set or get functions. fr fr, that's allowed — you don't have to fill in both, it's not a group project where everyone has to participate 💀

lowkey important: NULL here is fine and expected, not a bug. don't @ me.

🌈 SEE ALSO 🌈

Kernel file ./include/linux/moduleparam.h, plus the whole friend group:

and that's the whole page, bestie 💜 this lil masterpiece lives in ./include/linux, dropped October 2026, brought to you by the Kernel API Manual — go forth and parameterize responsibly, ily, mwah 🍓✨

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