revoke_delegation(9)

💅 revoke_delegation — like, the Kernel API Manual page, bestie ✨

Okay so welcome to revoke_delegation(9), a page about doing nfs4 delegation structure cleanup. Yes it sounds dry. No it's not. Sit down, grab a strawberry 🍓, we're learning.

---

🌸 NAME 🌸

revoke_delegation — performs nfs4 delegation structure cleanup, and honestly? it's giving janitor energy and I respect it 💅

---

✨ SYNOPSIS ✨

void revoke_delegation (struct nfs4_delegation *dp );

That's it. That's the whole signature. Iconic, lowkey.

---

🎀 ARGUMENTS 🎀

• dp — pointer to the delegation, aka the main character of this whole function 🫶

---

🦋 DESCRIPTION 🦋

So here's the vibe check fr fr. This function assumes it's being called from one of two places, and it is not here to double-check your work:

1. From the administrative interface, nfsd4_revoke_states, which is revoking a specific delegation stateid.
2. From a laundromat thread, nfsd4_landromat, which determined that this specific state has expired and needs to be revoked.

Both of those mark the state with the appropriate stid sc_status mode, iykyk. It is also assumed that a reference was taken on the dp state — and heads up, this function consumes that reference. So like, it's yours no more. Gone. Consumed. 🙈

Now the fun part, the actual branching 🌈:

• If this function finds that the dp state is SC_STATUS_FREED, that means a FREE_STATEID operation for this stateid has already been processed, and we can proceed to removing it from the recalled list. Slay, we're basically done.
• But if the dp state isn't marked SC_STATUS_FREED, that means we need to place it on the cl_revoked list and wait for the FREE_STATEID to arrive from the client. So we're waiting. Patiently. 🧚

At the same time, we need to mark it as SC_STATUS_FREEABLE to indicate to the nfsd4_free_stateid function that this stateid has already been added to the cl_revoked list, and that nfsd4_free_stateid is now responsible for removing it from the list. Passing the baton, periodt. 🔥

Inspection of where the delegation state is in the revocation process is protected by the clp->cl_lock. Take that lock seriously, bestie, it's the vibe check for concurrency 💀

---

👑 SEE ALSO 👑

Kernel file ./fs/nfsd/nfs4state.c, plus the whole friend group:

• nfs4_delegation_exists(9)
• hash_delegation_locked(9)
• nfs4_replay_free_cache(9)
• nfsd4_revoke_states(9)
• nfsd4_revoke_export_states(9)
• nfsd_slot_shrinker_count(9)
• nfsd_slot_shrinker_scan(9)
• nfsd4_put_client(9)
• nfsd_wait_for_delegreturn(9)
• nfsd_breaker_owns_lease(9)
• nfsd4_deleg_lm_open_conflict(9)
• nfsd4_process_open2(9)
• nfsd4_force_end_grace(9)
• nfs4_preprocess_stateid_op(9)
• nfs4_preprocess_seqid_op(9)
• nfsd4_release_lockowner(9)
• nfsd4_vet_deleg_time(9)
• nfsd4_deleg_getattr_conflict(9)
• nfsd_get_dir_deleg(9)
• nfsd_update_cmtime_attr(9)

---

Quick reminder bestie: this page lives at ./fs/nfsd and it's dated October 2026 — so mark your calendar, mwah 💖 That's the whole page, go take a delegation reference and consume it responsibly, ily! 🎀