fsverity_verify_bio(9)

💅 fsverity_verify_bio(9) — the kernel API manual, but make it make sense 🎀

okay bestie, so this is a page straight out of the Kernel API Manual (the fsverity_verify_bio(9) one, yes, that's the whole title, we love a self-referential moment) — and it's lowkey iconic actually. sit down, hydrate, let's get into it 🦋

---

✨ NAME ✨

fsverity_verify_bio — verify a 'read' bio that has just completed. that's it. that's the vibe. a bio finishes reading and we're like "girl, prove it" 💅

---

🌸 SYNOPSIS 🌸

void fsverity_verify_bio (struct fsverity_info *vi , struct bio *bio );

not me copy-pasting the signature exactly so nobody comes for me — returns void, takes two args, slay ✨

---

🎀 ARGUMENTS 🎀

• vi — the fsverity_info for the inode to be read. the receipts, basically 🧾
• bio — the bio to verify. the thing that just came back from the read and now has to answer for itself 💀

---

🔥 DESCRIPTION 🔥

so here's the tea ☕: this verifies the bio's data against the file's Merkle tree. that's the whole job. no cap.

hard requirement alert 🚨 — all bio data segments must be aligned to the file's Merkle tree block size. must. like, non-negotiable. if any data fails verification, then bio->bi_status is set to an error status. that's how the failure gets reported back — it's giving "you will be dealt with" and honestly? fair.

this is a helper function for use by the ->readahead method of filesystems that issue bios to read data directly into the page cache. so if your fs is out here doing that, this is your girl 🫶

⚠️ but listen — filesystems that populate the page cache without issuing bios (e.g. non block-based filesystems) must instead call fsverity_verify_blocks directly. different path, same energy. don't skip it.

also, and this part matters: all filesystems must also call fsverity_verify_blocks on holes. yes, all of them. holes get checked too. no exceptions, periodt 💯

---

👑 SEE ALSO 👑

• Kernel file ./fs/verity/verify.c
• fsverity_readahead(9)
• fsverity_verify_blocks(9)
• fsverity_enqueue_verify_work(9)

iykyk — go read them if you want the full lore 📚

---

🌈 the sign-off 🌈

so ./fs/verity is the source, this dropped October 2026, and the page itself is fsverity_verify_bio(9) — we've come full circle and honestly? main character energy ⭐💜

now go verify your bios bestie, and remember: aligned segments or it's not happening 💅✨🍓