nfsd4_cancel_copy_by_sb(9)

💅 nfsd4_cancel_copy_by_sb(9) 💅

okay so bestie, welcome to the Kernel API Manual entry for nfsd4_cancel_copy_by_sb — yes that name is a mouthful, no I will not be shortening it, and yes it's giving very much "function that knows what it wants." 🎀

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✨ NAME ✨

nfsd4_cancel_copy_by_sb — cancels the async copy operations happening on @sb. that's the whole vibe. it comes in, it shuts things down, it leaves. 💅

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🌸 SYNOPSIS 🌸

void nfsd4_cancel_copy_by_sb (struct net *net , struct super_block *sb );

literally just two args and no return value. it returns void, meaning it does not report back to you. it's not ghosting you, it's just built different. 🦋

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💖 ARGUMENTS 💖

• net — the net namespace that's holding the copy operations. think of it as the group chat these copies are living in. 🔥
• sb — the targeted superblock. the main character of this whole operation, honestly. 👑

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🫶 CONTEXT 🫶

okay this part is serious, so like, pay attention bestie. 😭

The caller must hold nfsd_mutex with NFSD_NET_UP set. not optional. not "eh probably fine." this is the rule.

why? because outside that window, nn->conf_id_hashtbl is unallocated or freed — and if you go walking through it anyway, you're gonna dereference a NULL or dangling pointer. and that is not the slay you think it is. that's a crash. 💀

so fr fr: hold nfsd_mutex, have NFSD_NET_UP set, or don't call this. no cap. 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./fs/nfsd/nfs4proc.c
• set_change_info(9)
• nfsd4_has_active_async_copies(9)
• nfsd4_async_copy_reaper(9)
• nfsd4_do_async_copy(9)
• nfsd4_spo_must_allow(9)

the whole async copy friend group honestly — go read them, they all ate. ⭐

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and that's the page!! mwah 💜 this one's from ./fs/nfsd, dated October 2026, and it's living in the Kernel API Manual — sign-off complete, go touch some superblocks, ily, bye 🧚🍓