debugfs_enter_cancellation(9)

💅 debugfs_enter_cancellation(9) 💅

okay so bestie, welcome to the Kernel API Manual ✨ — today's main character is debugfs_enter_cancellation, and honestly? she's doing a LOT of emotional labor so your debugfs file can be removed without a whole crisis. let's get into it 🫶

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🌸 NAME 🌸

debugfs_enter_cancellation — enter a debugfs cancellation. that's it, that's the vibe 💖

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✨ SYNOPSIS ✨

void debugfs_enter_cancellation (struct file *file , struct
       debugfs_cancellation *cancellation );

like, yes, the line break is literally right there in the middle. we don't question it. we accept it. 💀

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🎀 ARGUMENTS 🎀

• file — the file being accessed. yes, that file. the one you're poking at 👀
• cancellation — the cancellation object. heads up bestie: the cancel callback inside of it must be initialized before you come through. no half-built cancellations allowed, that's not the vibe 🙈

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🦋 DESCRIPTION 🦋

so here's the situation. when a debugfs file gets removed, it literally has to wait for all active operations to finish. like, sit there. patiently. but plot twist: the operation itself might need to wait for hardware, or for some async process to complete, or honestly just... something similar. and that's a problem, because now you've got waiting on waiting, which can mean long waits or — and this is the scary part — even deadlocks. 😭 not iconic. not slay.

that's exactly why this function exists.

you call debugfs_enter_cancellation from inside a debugfs handler that might need to be cancelled. and the moment you call it? the cancellation's 'cancel' callback may be called. and when that happens, the move is: go call debugfs_leave_cancellation and get out of that debugfs handler function as soon as possible. like, wrap it up, exit stage left, thank u next 💅

🫶 important side note: the 'cancel' callback is only ever called in the context of some kind of debugfs_remove. so no random drive-by cancellations. iykyk.

⚠️ and this one's a hard rule, no cap: this function must be paired with debugfs_leave_cancellation. they're a matching set. besties. soulmates. don't leave one hanging. 🔥

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⭐ SEE ALSO ⭐

the whole friend group, in the order the manual says (i don't make the rules, i just keep every single detail of them):

Kernel file ./fs/debugfs/file.c — debugfs_file_get(9), debugfs_file_put(9), debugfs_leave_cancellation(9), debugfs_create_u8(9), debugfs_create_u16(9), debugfs_create_u32(9), debugfs_create_u64(9), debugfs_create_ulong(9), debugfs_create_x8(9), debugfs_create_x16(9), debugfs_create_x32(9), debugfs_create_x64(9), debugfs_create_size_t(9), debugfs_create_atomic_t(9), debugfs_create_bool(9), debugfs_create_str(9), debugfs_create_blob(9), debugfs_create_u32_array(9), debugfs_print_regs32(9), debugfs_create_regset32(9), debugfs_create_devm_seqfile(9)

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👑 and that's the page!! go forth, pair your cancellations, and remember: waiting on a wait is NOT the move. mwah 💜

this has been a ./fs/debugfs production, dated October 2026 — catching you in the kernel source next time, bestie 🧚✨

debugfs_enter_cancellation(9) — periodt. 🍓