rhashtable_free_and_destroy(9)

✨ rhashtable_free_and_destroy ✨

Okay bestie, welcome to the Kernel API Manual — this one's the cleanup queen of the rhashtable world: rhashtable_free_and_destroy, aka "free elements and destroy hash table" 💅

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🌸 SYNOPSIS 🌸

void rhashtable_free_and_destroy (struct rhashtable *ht , void
(*free_fn)(void *ptr, void *arg) , void *arg );

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🎀 ARGUMENTS 🎀

• ht — the hash table you're about to destroy, no cap. This is the main character of the operation 🫶
• free_fn — callback whose whole job is releasing the resources of an element ✨
• arg — the pointer that gets passed on through to free_fn, iykyk 🦋

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💖 DESCRIPTION 💖

So here's the vibe: this function stops an eventual async resize. Then, if free_fn is defined, it invokes free_fn for every single element so their resources get released. 🧚

⚠️ Heads up bestie, this part is literally so important: RCU protected readers may still be accessing the elements. So the releasing of resources has to happen in a compatible manner. Don't just yolo it 😭

After all that, it frees the bucket array. Slay.

Alsooo, this function will eventually sleep to wait for an async resize to complete 😴 — and the caller is responsible for making sure no further write operations occur in parallel. That's on you, not on the function, fr fr.

Once cancel_work_sync has returned, the deferred rehash worker is quiesced and — per the contract above — no other concurrent access to the rhashtable is possible. So the tables are owned exclusively by this function and can be walked without ht->mutex held. Iconic behavior honestly 👑

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🦋 SEE ALSO 🦋

Kernel file ./lib/rhashtable.c, plus the whole walk-and-shrink friend group 💜

• rhashtable_shrink(9)
• rhashtable_next_key(9)
• rhashtable_walk_enter(9)
• rhashtable_walk_exit(9)
• rhashtable_walk_start_check(9)
• __rhashtable_walk_find_next(9)
• rhashtable_walk_next(9)
• rhashtable_walk_peek(9)
• rhashtable_walk_stop(9)

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Alright bestie, that's the whole page 🍓 — brought to you by ./lib, dated October 2026, and filed under rhashtable_free_and_destroy(9). Go free those elements responsibly 💖✨