kernfs_link_sibling(9)

💅 kernfs_link_sibling — a kernel API manual, bestie edition

Okay so real talk: this is a page from the kernel API manual, section 9, and the function we're obsessing over today is kernfs_link_sibling. Yes it's a long name. Yes it ate. Let's get into it 🫶

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✨ NAME ✨

kernfs_link_sibling — the girlypop that links a kernfs_node into its sibling rbtree 🌸

✨ SYNOPSIS ✨

int kernfs_link_sibling (struct kernfs_node *kn );

✨ ARGUMENTS ✨

• kn — the kernfs_node of interest 💖 like, this is the node we're talking about, the main character of this whole operation honestly

✨ DESCRIPTION ✨

So here's the vibe: kernfs_link_sibling links kn into its sibling rbtree — and that rbtree starts all the way up at kn->parent->dir.children. Yes, you read that right, we're going through the parent. 🦋

Locking tea ☕: kernfs_rwsem is held exclusive. No sharing, no friends, exclusive. Do not come for this function without holding it, fr fr.

✨ RETURN ✨

• 0 on success — slay, we ate 💅
• -EEXIST on failure — ngl, it's already there 😭

✨ SEE ALSO ✨

Kernel file ./fs/kernfs/dir.c — and here's the whole friend group, no cap:

• kernfs_path_from_node_locked(9)
• kernfs_name(9)
• kernfs_path_from_node(9)
• pr_cont_kernfs_name(9)
• pr_cont_kernfs_path(9)
• kernfs_get_parent(9)
• kernfs_name_hash(9)
• kernfs_unlink_sibling(9)
• kernfs_get_active(9)
• kernfs_put_active(9)
• kernfs_drain(9)
• kernfs_get(9)
• kernfs_put(9)
• kernfs_node_from_dentry(9)
• kernfs_add_one(9)
• kernfs_find_ns(9)
• kernfs_find_and_get_ns(9)
• kernfs_walk_and_get_ns(9)
• kernfs_create_root(9)
• kernfs_destroy_root(9)
• kernfs_root_to_node(9)
• kernfs_create_dir_ns(9)
• kernfs_create_empty_dir(9)
• kernfs_next_descendant_post(9)
• kernfs_activate(9)
• kernfs_show(9)
• kernfs_remove(9)
• kernfs_break_active_protection(9)
• kernfs_unbreak_active_protection(9)
• kernfs_remove_self(9)
• kernfs_remove_by_name_ns(9)
• kernfs_rename_ns(9)

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And that's the whole page, bestie 🎀 This one's from ./fs/kernfs, dated October 2026, and it lives at kernfs_link_sibling(9) — go off, icon 👑