libnvmf_registry_update(9)

📦 version 3.2, in arch rolling

💅 libnvmf_registry_update — update an attribute in a controller's registry entry

okay so bestie, this one's from the libnvme API manual and honestly it's giving "tiny function, big responsibility" ✨ it lives in section 9 and it's all about poking at one little attribute inside a controller's registry entry. let's get into it 🎀

✨ SYNOPSIS ✨

int libnvmf_registry_update (struct libnvme_global_ctx *ctx , const char
*device , const char *attr , const char *value );

🌸 ARGUMENTS 🌸

  • ctx — the libnvme global context, and no cap, it must not be NULL 🙅‍♀️ like, that's non-negotiable.
  • device — the kernel device name, e.g. "nvme3" 🖥️
  • attr — the name of the attribute you wanna update, e.g. "owner" 🏷️
  • value — the new attribute value ✍️ … or NULL if you'd rather nuke the attribute file entirely 💀

🦋 DESCRIPTION 🦋

so what does it actually do. it writes the attribute value into the controller's registry entry, and it does it the safe way — via an atomic tmp-file rename. it's giving "write it somewhere else first, then swap it in" main character energy 👑

and if the entry doesn't exist yet? don't stress, it gets created atomically the exact same way as on connect, including the best-effort seqnum stamp for the udev cleanup rule 🔥 (that little stamp is best-effort, so like… it tries its best, ok? 🙈)

now, the NULL case: if value is NULL, the attribute file gets removed instead of written. and here's the cute little caveat — in that case, a missing entry is simply left alone 🫶 no drama, no error, it just doesn't touch anything.

⭐ RETURN ⭐

  • 0 on success, slay 💖
  • a negative errno from the underlying system calls otherwise 😭 (straight from the syscalls, no filters)
ngl, the errno is negative here — so like, don't go comparing it to positive errno values, bestie, that's not the vibe check you want 💅

okay that's the whole page, no gatekeeping 🌈 this was libnvmf_registry_update from the libnvme API manual, dated October 2026 — mwah, go forth and update those registry attributes responsibly 🧚💜

📦 where this page comes from