check_code(9)

💅 check_code(9) — yes bestie, it's a whole kernel man page

okay so this is check_code from section 9 of the manual (kernel API vibes only, no cap), and she's a little validation bouncer. Let's get into it 🫶

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✨ NAME ✨

check_code — literally just checks the result of a state validation. that's the whole gig. 💅

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🦋 SYNOPSIS 🦋

bool check_code (bool valid , const struct admin_state_code *code ,
const char *what , struct vdo_completion *waiter );

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🎀 ARGUMENTS 🎀

• valid — True if the code is of an appropriate type. this is the vibe check itself, bestie.
• code — the code which failed to be of the correct type. yeah. she failed. 😭
• what — what the code failed to be, for logging. basically the "you were supposed to be XYZ" note so the logs know what to cry about.
• waiter — the completion to notify of the error; may be NULL. so like, optional plus-one. 🙈

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🌸 DESCRIPTION 🌸

the way that this function is so simple:

if the result failed → log an invalid state error, and then, if there is a waiter, notify it. that's it. no extra lore. they just want the error logged and the waiter told. 🎀✨

ngl, waiter being allowed to be NULL is the whole plot twist here. no waiter? no notification. just a sad little log entry and we move on. 💀

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⭐ RETURN ⭐

the result of the check. she returns the check's result, periodt. 👑

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🌈 SEE ALSO 🌈

the kernel file ./drivers/md/dm-vdo/admin-state.c and this absolutely iconic friend group:

• get_next_state(9)
• vdo_finish_operation(9)
• begin_operation(9)
• start_operation(9)
• assert_vdo_drain_operation(9)
• vdo_start_draining(9)
• vdo_finish_draining(9)
• vdo_finish_draining_with_result(9)
• vdo_assert_load_operation(9)
• vdo_start_loading(9)
• vdo_finish_loading(9)
• vdo_finish_loading_with_result(9)
• assert_vdo_resume_operation(9)
• vdo_start_resuming(9)
• vdo_finish_resuming(9)
• vdo_finish_resuming_with_result(9)
• vdo_resume_if_quiescent(9)
• vdo_start_operation(9)
• vdo_start_operation_with_waiter(9)

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that's the whole page, bestie — go check some codes, stay valid 💜

sign-off time 🎀 this little masterpiece lives in ./drivers/md/dm-vdo, dated October 2026, and you've been reading check_code(9) the entire time. slay. 🦋✨🔥