ubi_major2num(9)

💅 ubi_major2num — a kernel API moment (manual section 9)

okay so bestie, you're in the Kernel API Manual and today's main character is ubi_major2num(9). yes it's a whole vibe. let's get into it ✨

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🌸 NAME 🌸

ubi_major2num — get the UBI device number by character device major number. literally that's the whole gig 🎀

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⭐ SYNOPSIS ⭐

int ubi_major2num (int major );

no cap, that's the signature. keep it exactly like that 🫶

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🦋 ARGUMENTS 🦋

• major — the major number. that's it. that's the argument. it's giving simple and iconic 💅

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💖 DESCRIPTION 💖

so what does it do? this function searches for the UBI device number object by its major number, bestie 🔍 iykyk

if the UBI device was not found, this function returns -ENODEV 😭 otherwise, the UBI device number is returned ✨ slay.

lowkey important: -ENODEV means "no device, bestie, it's not here." don't be surprised when you get it 🙈

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🔥 SEE ALSO 🔥

the whole friend group, fr fr — starting with the kernel file:

• Kernel file ./drivers/mtd/ubi/build.c and struct mtd_dev_param(9)
• ubi_volume_notify(9)
• ubi_notify_all(9)
• ubi_enumerate_volumes(9)
• ubi_get_device(9)
• ubi_put_device(9)
• ubi_get_by_major(9)
• kill_volumes(9)
• uif_init(9)
• uif_close(9)
• ubi_free_volumes_from(9)
• ubi_free_all_volumes(9)
• ubi_free_internal_volumes(9)
• io_init(9)
• autoresize(9)
• ubi_attach_mtd_dev(9)
• ubi_detach_mtd_dev(9)
• open_mtd_by_chdev(9)
• open_mtd_device(9)
• bytes_str_to_int(9)
• ubi_mtd_param_parse(9)

go read them all, they're all iconic, periodt 👑

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sign-off time 🧚 this page lives in ./drivers/mtd/ubi, dated October 2026 — and the whole thing is titled ubi_major2num(9) in case you forgot already 💜 byeee 💖