libnvme(2)

🌸 NAME 🌸

okay so bestie, welcome to the libnvme(2) API manual ✨ and today's main character is:

struct nvme_uring_cmd — the nvme uring command structure 💅 no cap, that's literally its whole job description.

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🦋 SYNOPSIS 🦋

here's the whole thing, character for character, don't touch a single semicolon or she WILL bite:

struct nvme_uring_cmd {
    __u8 opcode;
    __u8 flags;
    __u16 rsvd1;
    __u32 nsid;
    __u32 cdw2;
    __u32 cdw3;
    __u64 metadata;
    __u64 addr;
    __u32 metadata_len;
    __u32 data_len;
    __u32 cdw10;
    __u32 cdw11;
    __u32 cdw12;
    __u32 cdw13;
    __u32 cdw14;
    __u32 cdw15;
    __u32 timeout_ms;
    __u32 rsvd2;
 };

look at her 🥹 so organized. so struct-shaped.

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🎀 Members 🎀

one by one, the full roster, nobody gets left out:

• opcode — the Operation code, bestie. go check enum nvme_io_opcodes and enum nvme_admin_opcodes if you wanna know your options 👀
• flags — not supported 🙈 it was intended for command flags (eg: SGL, FUSE) but it's just sitting there, decorative, unserious.
• rsvd1 — Reserved for future use ✨ (manifesting that future, tbh)
• nsid — Namespace Identifier, or the Fabrics type. two jobs, one field, she's versatile 💅
• cdw2 — Command Dword 2 (no spec defined use). she's free-spirited. ungoverned.
• cdw3 — Command Dword 3 (no spec defined use). same vibe, different dword 💀
• metadata — User space address to metadata buffer (NULL if not used). no thoughts, just address 🫶
• addr — User space address to data buffer (NULL if not used). the data one this time, not the metadata one, don't get it twisted ⭐
• metadata_len — Metadata buffer transfer length. how much metadata we talkin' 📏
• data_len — Data buffer transfer length. how much data we talkin' 📏✨
• cdw10 — Command Dword 10 (command specific) 🔥
• cdw11 — Command Dword 11 (command specific) 🔥
• cdw12 — Command Dword 12 (command specific) 🔥
• cdw13 — Command Dword 13 (command specific) 🔥
• cdw14 — Command Dword 14 (command specific) 🔥
• cdw15 — Command Dword 15 (command specific) 🔥 the whole dword squad. iconic lineup, truly.
• timeout_ms — If non-zero, overrides system default timeout in milliseconds ⏰ yes bestie, you can just. overrule the system. when you set it. when it's non-zero. slay.
• rsvd2 — Reserved for future use (and fills an implicit struct pad

and yeah, that last one literally just. cuts off there in the source 🧚 i am not finishing that sentence for you, i refuse, that's not my business, i don't make the rules 💀 she said "(and fills an implicit struct pad" and then simply stopped speaking. queen behavior honestly.

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and that's the whole page, bestie!! 💖 this was struct nvme_uring_cmd, brought to you by the libnvme(2) API manual, dated July 2026 🌈 go forth and uring, and remember: reserved fields are reserved for a reason, no touching 🙅‍♀️ periodt 🎀🦋✨