netdev_has_u..._dev_all_rcu(9)

📦 version 7.3.1, in nixpkgs unstable

💖 netdev_has_upper_dev_all_rcu(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — yes, the Kernel API Manual, that's the manual name, we're in the big leagues now 🎀. Today's main character is a lil boolean function that answers one very specific question about your network devices, and honestly? it ate. let's get into it 🦋

✨ NAME ✨

netdev_has_upper_dev_all_rcu — Check if device is linked to an upper device 💅

🌸 SYNOPSIS 🌸

bool netdev_has_upper_dev_all_rcu (struct net_device *dev , struct net_device *upper_dev );

like literally just hand it two devices and it'll tell you yes or no, no cap 🔥

🎀 ARGUMENTS 🎀

  • dev — the device. that's it, that's the whole vibe. it's your starting point, the main character of this little story 👑
  • upper_dev — the upper device you're checking for. the one we're like "hmm, is this one linked?" about 🙈

🦋 DESCRIPTION 🦋

So the whole point: you wanna find out if a device is linked to the specified upper device, and it returns true in case it is. Simple, clean, iconic ✨.

But wait, there's a plot twist — it checks the entire upper device chain, not just the immediate one. so it's giving "we went through the whole friend group to find this person" energy 💀. very thorough of it, honestly obsessed.

⚠️ and bestie, listen to me: the caller must hold rcu lock. that's not a suggestion, that's a requirement. hold the lock, or don't come crying to me 😭🔒

💜 SEE ALSO 💜

the squad 💅 — all of these live in the kernel file ./net/core/dev.c:

iykyk 😌 the whole dev.c friend group showed up fr fr 🌈

💫 sign-off 💫

and that's the tea, bestie 🍓 this lil page comes to you from the <./net/core> corner of the kernel and it's dated October 2026 📅 — so like, future vibes, but make it timeless 💜. go forth, hold that rcu lock, and slay ✨🧚‍♀️💅

📦 where this page comes from