radix_tree_iter_replace(9)

📦 version 7.3.1, in nixpkgs unstable

💅 radix_tree_iter_replace — bestie's guide to swapping items in a slot

okay so this is a page from the Kernel API Manual, and it's about radix_tree_iter_replace — the function that swaps out whatever's sitting in a slot while you're iterating. it's giving "surgical little swap" and honestly? iconic 🎀

✨ SYNOPSIS ✨

void radix_tree_iter_replace (struct radix_tree_root *root , const
struct radix_tree_iter *iter , void __rcu **slot , void *item );

like, five things going on in that signature and every one of them matters, no cap 💅

🌸 ARGUMENTS 🌸

  • root — the radix tree root. your tree. the whole vibe starts here 🌳
  • iter — iterator state. it's holding the place in the walk for you 🫶
  • slot — pointer to the slot. like, the actual address of the thing you're touching 📍
  • item — the new item to store in the slot. the glow-up ✨

🦋 DESCRIPTION 🦋

so this one is for use with radix_tree_for_each_slot. that's the whole reason it exists, fr fr — it's the replace call that lives inside that loop.

💀 the caveat, and do not skip this one: the caller must hold the tree write locked. not read. not "eh, probably fine." write locked. iykyk, but like, actually know it 😭

👑 SEE ALSO 👑

kernel file ./lib/radix-tree.c — that's the source, go read it, it's a whole journey 📖

and the family reunion of related functions, all of them, in order:

like, that's the whole friend group, they all show up 🫶

and that's the page, bestie! 🌈 sign-off time: this one comes from ./lib, dated October 2026 — screenshot it, pin it, live by it 💖🎀🌸

📦 where this page comes from