blk_crypto_evict_key(9)

💅 blk_crypto_evict_key(9) — a Kernel API Manual moment ✨

okay so bestie, welcome to the Kernel API Manual, and today's main character is blk_crypto_evict_key 🎀 lowkey a little function with big "clean up your room before you leave" energy.

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🌸 NAME 🌸

blk_crypto_evict_key — evict a blk_crypto_key from a block_device 🦋

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✨ SYNOPSIS ✨

void blk_crypto_evict_key (struct block_device *bdev , const struct
blk_crypto_key *key );

literally that's the whole signature, no cap.

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🫶 ARGUMENTS 🫶

• bdev — a block_device on which I/O using the key may have been done 👀 like, the device where this key was actually out here living its life.
• key — the key to evict 🗝️ bye bestie, your time is up.

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💖 DESCRIPTION 💖

So for a given block_device, this function removes the given blk_crypto_key from the keyslot management structures, and evicts it from any underlying hardware keyslot(s) or blk-crypto-fallback keyslot it may have been programmed into. it's giving "spring cleaning but for cryptographic key slots" 🧹✨

Upper layers must call this before freeing the blk_crypto_key. not optional, not a suggestion, it's a must fr fr. 🙈

It must be called for every block_device the key may have been used on — like, all of them, not just the one you remember. 🔥

And the key must no longer be in use by any I/O when this function is called. periodt. 💅

⚠️ warning bestie: key still doing I/O? do NOT call this. free the key without calling this? also do not. the vibes will be rancid and that's on you 😭

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🎀 CONTEXT 🎀

May sleep. 😴 so like, don't hit it from a context where sleeping is illegal, you know the drill.

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🌈 SEE ALSO 🌈

• Kernel file ./block/blk-crypto.c 📁
• blk_crypto_init_key(9)
• blk_crypto_config_supported_natively(9)
• blk_crypto_start_using_key(9)

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✨ that's the whole page, you ate that ✨ 💜

source: ./block · date: October 2026 · blk_crypto_evict_key(9) — mwah, go evict those keys responsibly 🍓🧚👑