libnvmf_ker...on_supported(9)

📦 version 3.2, in arch rolling

💅 libnvmf_ker...on_supported(9) — from the libnvme API manual, bestie

okay so picture this: you're in the libnvme API manual, section 9, and you stumble into libnvmf_ker...on_supported. yeah the name is doing the absolute most with those ellipses, but stick with me because this little function is genuinely iconic. ✨

🌸 NAME 🌸

libnvmf_kernel_option_supported — literally just checks if your kernel supports an option. that's it. that's the whole gig. 💖

🎀 SYNOPSIS 🎀

int libnvmf_kernel_option_supported (struct libnvme_global_ctx *ctx ,
const char *name , bool *supported );

like yes, three arguments, no drama, copy it exactly as written because we do not freestyle signatures around here. 🫶

🦋 ARGUMENTS 🦋

  • ctx — your libnvme global context. the main character of the whole libnvme situation tbh. 👑
  • name — the option name, and it has to be spelled exactly how the kernel lists it in /dev/nvme-fabrics. think "discovery", "tls", "ctrl_loss_tmo". no vibes-based guessing, the strings have to match fr fr. ⭐
  • supported — this is where the answer lands. it gets set to true if the kernel supports name. 🍓

✨ DESCRIPTION ✨

so here's the tea: the options get read from /dev/nvme-fabrics, and that read happens once per ctx. so it's not re-reading every single time, it's caching the vibe check, iykyk. 💅

⚠️ heads up bestie: that read blocks while another process is busy connecting a controller. so if it feels like it's just sitting there, it's not ghosting you — it's waiting its turn. 🙈

🔥 RETURN 🔥

  • 0 — success! everything slayed, no notes. 🌈
  • -EINVAL — one of the arguments is NULL. classic. 💀
  • -EOPNOTSUPP — the kernel doesn't list its options at all, which is the case on Linux < 5.17. old kernel behaviour, not your fault. 😭
  • or honestly any other negative error code, because life finds a way. 🧚
💜 little recap because you're my bestie and i want you to win: read once per ctx, block on a controller connect, and check your args for NULL before you come crying to me about -EINVAL.

and that's the page! brought to you by the libnvme API manual, dated October 2026 — go forth and check those kernel options, you gorgeous nerd. 🎀💖✨

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