pcl_check_re...nk_positions(9)

📦 version 7.3.1, in nixpkgs unstable

🎀 NAME 🎀

okay bestie, this is the Kernel API Manual page for pcl_check_read_chunk_positions — aka the function that validates Read chunk positions. It’s literally the vibe check for chunk positions, and we’re obsessed. 💅✨

✨ SYNOPSIS ✨

bool pcl_check_read_chunk_positions (struct svc_rdma_recv_ctxt *rctxt ,
unsigned int inline_len );

🫶 ARGUMENTS 🫶

  • rctxt — Ingress receive context with populated chunk lists. That’s the ingress receive context, bestie, with the chunk lists already populated. 🫶
  • inline_len — Length of the inline RPC body after the transport header. No cap.

💅 DESCRIPTION 💅

Read chunk positions are offsets in the unreduced XDR stream (RFC 8166 Section 3.4.4), so each position includes the cumulative length of preceding Read chunks. This function subtracts those lengths to recover the inline-body offset before comparing against inline_len or the Call chunk length. 🧚

It rejects frames where:

  • a Read chunk’s inline-body offset exceeds the bound,
  • adjacent Read chunks overlap, or
  • any single chunk length exceeds the page budget.

Return values:

  • true — Read chunk positions and lengths are valid
  • false — Malformed chunk list detected

🔥 SEE ALSO 🔥

Kernel file ./net/sunrpc/xprtrdma/svc_rdma_pcl.c is the main-character file, and these are the friends in the group chat:

mwah 💋 — signed off from ./net/sunrpc/xprtrdma, October 2026. periodt. 🦋

📦 where this page comes from