svc_rdma_read_chunk_range(9)

💅 svc_rdma_read_chunk_range(9)

okay so bestie, welcome to the Kernel API Manual ✨ — today's main character is svc_rdma_read_chunk_range, and honestly? she's a baddie. She builds RDMA Read WRs for a portion of a chunk. Not the whole chunk. A portion. She's precise like that. 🎀

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🌸 NAME 🌸

svc_rdma_read_chunk_range — Build RDMA Read WRs for portion of a chunk

✨ SYNOPSIS ✨

int svc_rdma_read_chunk_range (struct svc_rqst *rqstp , struct
svc_rdma_recv_ctxt *head , const struct svc_rdma_chunk *chunk , unsigned
int offset , unsigned int length );

literally the whole signature, no cuts, no remixes. 🫶

🦋 ARGUMENTS 🦋

• rqstp — the RPC transaction context. the setting, the vibe, the whole situation 💜
• head — context for ongoing I/O. she's holding the lore for what's currently happening.
• chunk — the parsed Call chunk to pull from. the parsed part is important, iykyk 🧚
• offset — offset of the region to pull. where we start, periodt.
• length — length of region to pull. how much we're taking. no more, no less ✨

🔥 DESCRIPTION 🔥

so like, this function goes and builds those RDMA Read WQEs for a slice of a chunk, and then it tells you how it went. and because this is kernel land, "how it went" is a whole mood board of return values 💀

Return values:

• 0 — RDMA Read WQEs were successfully built. ate. no crumbs. 👑
• -EINVAL — there were not enough resources to finish 😭
• -ENOMEM — the rdma_rw context pool was exhausted 🫠
• -ENOTCONN — posting failed (connection is lost) 💀
• -EIO — rdma_rw initialization failed (DMA mapping, etc) 🙈

ngl bestie, when you see anything other than 0 come back, that's your sign to actually read the error instead of scrolling past it. every single one of those has a different cause and a different fix. the lore matters. 💅

🌈 SEE ALSO 🌈

the Kernel file lives right here, go be nosy:

./net/sunrpc/xprtrdma/svc_rdma_rw.c

and here's the whole friend group, fr fr — every single one, in order:

svc_rdma_destroy_rw_ctxts(9), svc_rdma_rw_ctx_init(9), svc_rdma_cc_init(9), svc_rdma_cc_release(9), svc_rdma_write_chunk_release(9), svc_rdma_reply_chunk_release(9), svc_rdma_reply_done(9), svc_rdma_write_done(9), svc_rdma_wc_read_done(9), svc_rdma_iov_write(9), svc_rdma_pages_write(9), svc_rdma_xb_write(9), svc_rdma_prepare_write_list(9), svc_rdma_prepare_reply_chunk(9), svc_rdma_build_read_segment(9), svc_rdma_build_read_chunk(9), svc_rdma_copy_inline_range(9), svc_rdma_read_multiple_chunks(9), svc_rdma_read_data_item(9), svc_rdma_read_call_chunk(9), svc_rdma_read_special(9), svc_rdma_process_read_list(9)

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okay that's the whole page, you're officially educated 💖 this one came from ./net/sunrpc/xprtrdma, dated October 2026, manual section svc_rdma_read_chunk_range(9) — and yes she served, we love her, mwah 🎀✨🦋