fscrypt_add_test_dummy_key(9)

✨ fscrypt_add_test_dummy_key ✨

okay so bestie, this one is straight out of the Kernel API Manual, section 9 — the page is literally called fscrypt_add_test_dummy_key(9), yes the title is the function name, the kernel does that, we stan a consistent naming convention 💅

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🌸 NAME 🌸

fscrypt_add_test_dummy_key — add the test dummy encryption key 🎀

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🎀 SYNOPSIS 🎀

int fscrypt_add_test_dummy_key(struct super_block *sb, struct fscrypt_key_specifier *key_spec);

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🫶 ARGUMENTS 🫶

• sb — the filesystem instance you're adding the key to, like the whole vibe container 🌈
• key_spec — the key specifier of the test dummy encryption key 👑

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💖 DESCRIPTION 💖

So what she does: she adds the key for the test_dummy_encryption mount option to the filesystem. periodt.

But here's the iconique part — to prevent misuse of this mount option, a per-boot random key is used instead of a hardcoded one. not me being grateful for that fr fr 🔥

And the way that works out is: this makes it so that any encrypted files created using this option won't be accessible after a reboot. gone. deleted. not coming back 😭 so like, don't get attached to your test files, they're giving fleeting main character energy.

no cap, that's the actual design — the key is per-boot and random, so post-reboot access is a no 🚫

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⭐ RETURN ⭐

0 on success, -errno on failure. that's the whole report card 💀

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👑 SEE ALSO 👑

Kernel file ./fs/crypto/keyring.c — go read her, she ate 🦋

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mwah 💋 that's the whole page, sourced from ./fs/crypto and dated October 2026, signed off from the Kernel API Manual by yours truly — happy key-adding bestie 🍓✨