__kernfs_create_file(9)

🦋 __kernfs_create_file(9) — like, the kernel API manual page, bestie 🦋

okay so this is a page straight outta the Kernel API Manual, and it's about a kernfs internal function that creates a file. yes, internal. no cap, that word is doing a lot of heavy lifting here so keep it in mind 👀

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✨ NAME ✨

__kernfs_create_file — the kernfs internal function that creates a file 💅

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✨ SYNOPSIS ✨

struct kernfs_node * __kernfs_create_file (struct kernfs_node *parent ,
const char *name , umode_t mode , kuid_t uid , kgid_t gid , loff_t size
, const struct kernfs_ops *ops , void *priv , const struct ns_common *ns
, struct lock_class_key *key );

it's giving "ten whole arguments, and every single one of them matters" 🎀

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✨ ARGUMENTS ✨

• parent — the directory you're creating the file in. it's the vibe check location, iykyk 📁
• name — the name of the file ✏️
• mode — the mode of the file 🔐
• uid — the uid of the file 🫶
• gid — the gid of the file 🫶
• size — the size of the file 📏
• ops — the kernfs operations for the file ⚙️
• priv — private data for the file 🍓
• ns — optional namespace tag of the file. optional, bestie, so don't stress 🌸
• key — the lockdep key for the file's active_ref, and <italic>NULL</italic> to disable lockdep 💀

literally so important: key being NULL disables lockdep. that's the documented behavior, not me being dramatic (for once) 🙈

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✨ RETURN ✨

the created node on success ✨ — and an ERR_PTR value on error 😭

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✨ SEE ALSO ✨

• the Kernel file ./fs/kernfs/file.c
• of_on(9)
• kernfs_deref_open_node_locked(9)
• kernfs_get_open_node(9)
• kernfs_unlink_open_file(9)
• kernfs_notify(9)

go read the source, it's iconic 👑

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and that's the whole page omg 🎀 this one lives under ./fs/kernfs, dated October 2026, and it's __kernfs_create_file(9) — go forth and create files responsibly, bestie 💖🦋✨