svc_rdma_encode_write_chunk(9)

📦 version 7.3.1, in nixpkgs unstable

💖 svc_rdma_encode_write_chunk — the Kernel API Manual page, bestie edition 💖

okay so this is a page from the Kernel API Manual, and it's about a function called svc_rdma_encode_write_chunk. it's short, it's sweet, and it's giving "small function, big job" energy. let's get into it 🫶

✨ NAME ✨

svc_rdma_encode_write_chunk — Encode one Write chunk

like, literally just one. singular. one chunk. 💅

🌸 SYNOPSIS 🌸

ssize_t svc_rdma_encode_write_chunk (struct svc_rdma_send_ctxt *sctxt ,
const struct svc_rdma_chunk *chunk );

that's the whole signature, no cap. it returns an ssize_t, so yes, it's gonna hand you back a signed size — keep that in mind for the return values later 👀

🎀 ARGUMENTS 🎀

  • sctxt — Send context for the RPC Reply. this is the send context, bestie. it's the Reply's whole little setup. 🦋
  • chunk — Write chunk to push. the actual Write chunk you're pushing out. that's it, that's the argument. 🌈

💜 DESCRIPTION 💜

so here's the vibe: this function copies a Write chunk from the Call transport header over to the Reply transport header. that's the main character move. 🔥

and it doesn't just copy — it also updates each segment's length field to reflect the number of bytes written in that segment. every single segment gets its length field refreshed. it's giving detail-oriented icon behavior. ✨

Return values:

  • On success, returns length in bytes of the Reply XDR buffer that was consumed by the Write chunk.
  • -EMSGSIZE on XDR buffer overflow. 😭 (that's the sad one, the buffer said "no more room")
ngl, that -EMSGSIZE is the one you're gonna be checking for. if the XDR buffer overflows, that's your error code right there. not me being dramatic, it's just in the manpage. 💀

🌟 SEE ALSO 🌟

Kernel file ./net/sunrpc/xprtrdma/svc_rdma_sendto.c

and the whole friend group 🫶 (fr fr, this is a long list, but every single one is here):

and that's the page!! 🎀 source path ./net/sunrpc/xprtrdma, dated October 2026 — mwah, slay, periodt. go read svc_rdma_sendto.c if you wanna see it in the wild, iykyk 💖👑

📦 where this page comes from