async_syndrome_val(9)

💅 async_syndrome_val — or, "let's check that raid6 syndrome, but make it async"

okay so bestie, you found a kernel API manual page 💖 welcome, this one lives in the Kernel API Manual and it's about async_syndrome_val — asynchronously validate a raid6 syndrome. yes that's the whole NAME section, she's short and she's iconic ✨

🌸 SYNOPSIS

struct dma_async_tx_descriptor * async_syndrome_val (struct page
**blocks , unsigned int *offsets , int disks , size_t len , enum
sum_check_flags *pqres , struct page *spare , unsigned int s_off ,
struct async_submit_ctl *submit );

like, look at her. returns a struct dma_async_tx_descriptor *, takes a whole little friend group of arguments 🫶 full breakdown below, no skipping ✨

🎀 ARGUMENTS

• blocks — the source blocks, indexed from 0..disks-3, then P at disks-2 and Q at disks-1. so the P and Q blocks are literally the last two seats in the row, iykyk 💅
• offsets — the common offset into each block (both src and dest, bestie) where the transaction starts. one offset to rule them all ✨
• disks — the number of blocks, including any missing P or Q — see below, there's lore 👀
• len — length of the operation, in bytes. numbers, we love her 📏
• pqres — if the validation fails, SUM_CHECK_P_RESULT and/or SUM_CHECK_Q_RESULT get set here. it's giving "receipts" 🧾
• spare — a temporary result buffer, needed for the synchronous case 💀 yes, temporary. don't get attached.
• s_off — the spare buffer's page offset 🎀
• submit — the submission / completion modifiers, aka the vibe check for how this transaction goes down 🔥

🦋 DESCRIPTION

so the same notes from async_gen_syndrome apply to the blocks and disks parameters of this routine — like, go read that one too, bestie, it's a whole thing 📚

and the synchronous path? it requires a temporary result buffer and submit->scribble to be specified. not optional. not negotiable. literally required, no cap 🚨

🌈 SEE ALSO

• Kernel file ./crypto/async_tx/async_pq.c 📁
• async_gen_syndrome(9) 👑

that's the whole page, periodt 💖 she came from ./crypto/async_tx, dated October 2026, and she's filed under the Kernel API Manual. go forth and validate those syndromes, bestie 🌸🦋✨