NVME_IDENTIFY_IOCS_NS_CSI_USER_DATA_FORMAT(2)

✨ nvme_identify_iocs_ns_csi_user_data_format ✨

okay bestie, so we're in the libnvme API manual today and the star of the show is nvme_identify_iocs_ns_csi_user_data_format — yes it's a whole mouthful, yes you're gonna say it in one breath, periodt. 💅

This one's all about asking a namespace "hey girl, what can you actually DO with this specific data format?" It's giving very ✨capability interrogation✨ energy.

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🌸 SYNOPSIS 🌸

int nvme_identify_iocs_ns_csi_user_data_format (int fd , __u16
user_data_format , __u8 uuidx , enum nvme_csi csi , void *data );

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🎀 ARGUMENTS 🎀

• fd — the file descriptor of your nvme device, your lil VIP pass to the hardware 🔑
• user_data_format — this is the identifier you use to return the namespaces capability of, iykyk
• uuidx — UUID selection, but only if it's supported babes, don't get your hopes up blindly 🦋
• csi — the Command Set Identifier, aka which command set we're talking about
• data — user space destination address where the data gets transferred to, the lil landing pad for your goods 📦

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💖 DESCRIPTION 💖

So here's the tea: this function gets you the I/O Command Set specific Identify Namespace data structure for whatever User Data Format index you slid in there, and it's packed with all the namespace capabilities for the I/O Command Set you named in the csi field. No cap, it's literally the namespace showing off its skill tree for that exact format. 🔥

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🫶 RETURN 🫶

It hands you back the nvme command status if a response actually came through (peep enum nvme_status_field for the deets), or it gives you -1 with errno set in literally every other case. So bestie, if you see that -1, go read errno before you spiral. 😭

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lowkey reminder: check that return value every single time, the way that -1 can sneak up on you is giving main character betrayal 💀

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July 2026, libnvme API manual — the nvme_identify_iocs_ns_csi_user_data_format(2) page said its goodbyes, slay, go identify some namespaces bestie 👑✨🌈