ns_tree_node_add(9)

💖 ns_tree_node_add(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — this is the page for ns_tree_node_add, and honestly? it's giving "one function, two data structures, zero chill" 💅 let's get into it.

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🎀 NAME 🎀

ns_tree_node_add — Add a node to a namespace tree 🌸

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✨ SYNOPSIS ✨

struct rb_node * ns_tree_node_add (struct ns_tree_node *node , struct
       ns_tree_root *root , int (*cmp)(struct rb_node *, const struct rb_node
       *) );

like. look at that signature. she's iconic, she's long, she returns a struct rb_node * and we love her for it 🫶

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🌈 ARGUMENTS 🌈

• node — the node you're adding, bestie. the actual star of the show 👑
• root — the tree root you're adding it to. gotta know where home is 🏡
• cmp — the comparison function for rbtree insertion. ngl she's doing a lot of the heavy lifting here, respect her 💅

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🦋 DESCRIPTION 🦋

okay so here's the vibe: this function adds the node to both the rbtree and the list, and it maintains sorted order the whole time ✨ no cap, both structures stay in sync.

and the reason the list is maintained in the same order as the rbtree? so you can do efficient iteration 💫 literally that's the whole point — iterate the list, get rbtree order, chef's kiss 🧚

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💀 RETURN 💀

• NULL — if the insertion succeeded 🎉 (yes bestie, NULL means success here, do not panic, this is not an error, i promise 😭)
• existing node — if a duplicate was found 🙈

⚠️ lowkey important: read that return value carefully. NULL = slay, worked fine. a node pointer = duplicate already exists. the vibes are inverted from what you'd expect, so don't get caught out 💀

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🍓 SEE ALSO 🍓

Kernel file ./kernel/nstree.c, plus the whole friend group:

• ns_tree_node_init(9)
• ns_tree_root_init(9)
• ns_tree_node_empty(9)
• ns_tree_node_del(9)
• __ns_tree_adjoined_rcu(9)
• __ns_tree_gen_id(9)

go give them a read, they're all icons in their own right 💜

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and that's the page, bestie!! 🎀 this one came to you straight from ./kernel and it's dated October 2026 ⭐ so if you're reading this in some other timeline, wyd 👀 anyway ily, go add some nodes, and remember: NULL means you ate 🔥💅