guard_bio_eod(9)

📦 version 7.3.1, in nixpkgs unstable

💅 guard_bio_eod(9) 💅

okay so welcome to the Kernel API Manual, bestie — this little page is guard_bio_eod(9) and it's genuinely one of those tiny functions that saves your whole entire life 🫶

✨ NAME ✨

guard_bio_eod — truncate a BIO to fit the block device 🎀

🌸 SYNOPSIS 🌸

void guard_bio_eod (struct bio *bio );

that's it. that's the whole signature. short king behavior honestly 👑

🦋 ARGUMENTS 🦋

  • bio — the bio to truncate. yes it's just the one. she's low maintenance 💅

⭐ DESCRIPTION ⭐

so the whole point, and I need you to hear me on this: this lets us do IO even on the odd last sectors of a device — even when the block size is some multiple of the physical sector size. like, the math doesn't work out and we're still showing up to the function anyway 😭

we'll just truncate the bio down to the size of the device, and clear the end of the buffer head manually. no cap, that's the move ✨

and before you panic — truly out-of-range accesses will turn into actual I/O errors. this only handles the "we need to be able to do I/O at the final sector" case. that's the vibe check right there, don't ask her to do more 💀

🔥 SEE ALSO 🔥

kernel file ./block/bio.c and the whole friend group, fr fr:

like look at that lineup. main character energy all around 👑

🧚 and that's the page, bestie! this one came straight out of ./block, dated October 2026 — mwah, slay, periodt 💖🌈✨

📦 where this page comes from