nlm4svc_proc_cancel(9)

💅 nlm4svc_proc_cancel(9) — the Kernel API Manual, but make it cute 🎀

okay so bestie, you're in the nlm4svc_proc_cancel(9) page of the Kernel API Manual and honestly? this one's a little baddie with a very specific job. let's get into it ✨

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🌸 NAME 🌸

nlm4svc_proc_cancel — CANCEL: cancel an outstanding blocked lock request. that's it, that's the whole vibe. it's giving "never mind, forget I asked" energy 💅

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🦋 SYNOPSIS 🦋

__be32 nlm4svc_proc_cancel (struct svc_rqst *rqstp );

look at her. one argument, one return type, zero drama (well… mostly zero, keep reading bestie 😭).

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💖 ARGUMENTS 💖

• rqstp — the RPC transaction context. literally the whole receipts folder for this request, she's carrying everything the call needs 🫶

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✨ RETURN ✨

the function hands back one of these and you will respect them:

• rpc_success — RPC executed successfully. slay, it worked, we love a clean run 💜
• rpc_drop_reply — do not send an RPC reply. like, at all. mute the reply, periodt 🙈

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🔥 DESCRIPTION 🔥

so here's the RPC synopsis, and yes she's iconic:

nlm4_res NLMPROC4_CANCEL(nlm4_cancargs) = 3;

the CANCEL procedure is literally number 3. main character number, no cap 👑

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🎀 permissible procedure status codes 🎀

these are the status codes that are allowed to come back out of this thing — memorize them, they're on the test:

• NLM4_LCK_GRANTED — the requested lock was canceled. okay so the cancel worked, the lock is gone, mission accomplished ✨
• NLM4_LCK_DENIED — there was no lock to cancel. imagining cancelling something that never existed… awkward 😭 but legit!
• NLM4_DENIED_GRACE_PERIOD — the server has recently restarted and is re-establishing existing locks, and is not yet ready to accept normal service requests. she's in her healing era, give her a minute 🌸

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🧚 what the Linux NLM server also returns 🧚

the Linux NLM server implementation is extra and also returns these bad boys:

• NLM4_DENIED_NOLOCKS — a needed resource could not be allocated. no resources, no service, sad girl hours 💀
• NLM4_STALE_FH — the request specified an invalid file handle. the file handle was not giving what it needed to give 🙈
• NLM4_FBIG — the request specified a length or offset that exceeds the range supported by the server. too big, too far, out of range, we're not doing that 🚫
• NLM4_FAILED — the request failed for an unspecified reason. the classic "it didn't work and honestly nobody knows why" vibe check 😭💀

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🌈 SEE ALSO 🌈

kernel file ./fs/lockd/svc4proc.c 👀 and the whole entire friend group:

nlm4svc_proc_null(9), nlm4svc_proc_test(9), nlm4svc_proc_lock(9), nlm4svc_proc_unlock(9), nlm4svc_proc_granted(9), nlm4svc_proc_test_msg(9), nlm4svc_proc_lock_msg(9), nlm4svc_proc_cancel_msg(9), nlm4svc_proc_unlock_msg(9), nlm4svc_proc_granted_msg(9), nlm4svc_proc_granted_res(9), nlm4svc_proc_sm_notify(9), nlm4svc_proc_unused(9), nlm4svc_proc_share(9), nlm4svc_proc_unshare(9), nlm4svc_proc_nm_lock(9), nlm4svc_proc_free_all(9)

all of them. the full squad. go read them, iykyk 🫶

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ok final note bestie: this page lives under ./fs/lockd and it's dated October 2026 🌸 so yeah, she's from the future and she's still serving. mwah, love you, bye 💋✨