libnvme_get_feature_length(9)

📦 version 3.2, in arch rolling

💅 libnvme_get_feature_length(9) — the libnvme API manual, bestie

okay so picture this: you're deep in nvme-land, you've got a feature identifier in your hand, and you just need to know how many bytes the command payload is gonna be. that's literally the whole gig of this function. it's giving "one job, does it well" energy. ✨

🌸 NAME 🌸

libnvme_get_feature_length — retrieve the command payload length for a specific feature identifier 🎀

🦋 SYNOPSIS 🦋

int libnvme_get_feature_length (int fid , __u32 cdw11 , enum
nvme_data_tfr dir , __u32 *len );

✨ ARGUMENTS ✨

  • fid — the feature identifier, bestie. peep enum nvme_features_id for the full menu. 👑
  • cdw11 — a __u32, and lowkey it can affect the transfer. the only fid we know of where that happens is NVME_FEAT_FID_HOST_ID. the way that one specific case matters… 🙈
  • dir — the data transfer direction, and it's a bool situation: false means host to controller, true means controller to host. and yes, it may affect the transfer — the only fid we know of for that one is NVME_FEAT_FID_HOST_MEM_BUF. two little special cases, both iconic. 🫶
  • len — an __u32 *. on success, this gets set to the feature's payload length in bytes. it's the whole point tbh. 💖

🔥 RETURN 🔥

  • 0 on success — slay, you got your length. 🌈
  • -1 with errno set to EINVAL if the function did not recognize fid. like, it literally looked at your feature id and went "who is she". 💀 no cap, that's a you problem, double-check your fid.
no undefined behaviour warnings here, just a very polite "i don't know her" via EINVAL. still, fr fr, don't ignore that return value. ⭐

🎀 the cute little sign-off 🎀

this whole page came to you courtesy of the libnvme API manual, dated October 2026 — and the footer was out here trying to spell libnvme_get_feature_len before getting cut off mid-word, which is honestly such a mood. libnvme_get_feature_length(9), periodt. 💅🧚🍓

📦 where this page comes from