fscrypt_zeroout_range(9)

📦 version 7.3.1, in nixpkgs unstable

💅 fscrypt_zeroout_range(9) — the Kernel API Manual glow-up 🎀

okay bestie, welcome to the Kernel API Manual entry for fscrypt_zeroout_range(9) — yes that's the full manual name, we're fancy like that ✨

✨ NAME ✨

fscrypt_zeroout_range — zero out a range of blocks in an encrypted file 🫶

🌸 SYNOPSIS 🌸

int fscrypt_zeroout_range (const struct inode *inode , loff_t pos ,
       sector_t sector , u64 len );

🦋 ARGUMENTS 🦋

  • inode — the file's inode, like the file's main character ID 💖
  • pos — the first file position (in bytes) to zero out 📍
  • sector — the first sector to zero out 🧚
  • len — bytes to zero out, and yes it's counting bytes, not vibes 😭

🔥 DESCRIPTION 🔥

So what this actually does: it zeroes out filesystem blocks in an encrypted regular file on-disk — meaning it writes ciphertext blocks that decrypt to the all-zeroes block. Not me explaining crypto at 2am but here we are 💀

The blocks have to be both logically and physically contiguous. No skipping, no gaps, no chaos, periodt 💅

It's also assumed that the filesystem only uses a single block device, ->s_bdev. That's the vibe check it's operating under 👑

And len must be a multiple of the file system logical block size. Like, mandatory. No cap 🚨

Also important, bestie: since each block uses a different IV, this involves writing a different ciphertext to each block — we can't simply reuse the same one. Each block gets its own little encrypted outfit, iykyk 🌈

⭐ RETURN ⭐

0 on success; -errno on failure. Slay when it works, errno when it doesn't 😭

💜 SEE ALSO 💜

Kernel file ./fs/crypto/block.c and its besties:

and that's the whole page, iconically complete 💖✨🎀

source/version: ./fs/crypto · date: October 2026 · page: fscrypt_zeroout_range(9) — mwah, go read the kernel docs bestie 🫶💅

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