notifier_call_chain_robust(9)

📦 version 7.3.1, in nixpkgs unstable

👑 notifier_call_chain_robust — a Kernel API Manual moment 💅

okay so bestie, this is notifier_call_chain_robust(9) and honestly? it's giving responsible queen. it tells all the registered notifiers about an event, and if something goes wrong it rolls it back. no cap, it's the friend who texts the group chat and then un-sends the messy message. 🫶

✨ NAME ✨

notifier_call_chain_robust — Inform the registered notifiers about an event and rollback on error.

like literally, that's the whole vibe: notify everyone, and if the news was bad, politely take it back. 🎀

🌸 SYNOPSIS 🌸

int notifier_call_chain_robust (struct notifier_block **nl , unsigned
long val_up , unsigned long val_down , void *v );

copy that exactly, bestie, don't be typing it from memory 😭

🦋 ARGUMENTS 🦋

  • nl — Pointer to head of the blocking notifier chain. it's the head of the chain, the main character of this whole operation 👑
  • val_up — Value passed unmodified to the notifier function. unmodified, okay? we do not touch. we pass it through, pristine, like a fresh iced coffee 🍓
  • val_down — Value passed unmodified to the notifier function when recovering from an error on val_up. so like, the backup plan value 💜
  • v — Pointer passed unmodified to the notifier function. also untouched. also iconic. ✨

💀 NOTE 💀

It is important the nl chain doesn't change between the two invocations of notifier_call_chain such that we visit the exact same notifier callbacks; this rules out any RCU usage.

ngl this is the serious part, so listen up fr fr 🙈 — the chain has to stay the exact same between the two calls, so we hit the exact same callbacks both times. that means no RCU usage, periodt. don't try it. the vibe check fails. 💅

⭐ RETURN ⭐

the return value of the val_up call. that's it, that's the answer, we love a simple queen 🌈

🔥 SEE ALSO 🔥

Kernel file ./kernel/notifier.c and honestly the whole notifier friend group 💖:

and that's the page, bestie!! 🧚 from ./kernel, dated October 2026, this was notifier_call_chain_robust(9) — slay, stay robust, and don't change the chain mid-invocation 💅💖🎀

📦 where this page comes from