STRUCT P9_TRANS_RDMA(9)

💅 struct p9_trans_rdma — the RDMA transport instance bestie ✨

okay so this page lives in the Kernel API Manual (that's section 9 of the manual, iykyk) and it's literally all about struct p9_trans_rdma 🎀 — the RDMA transport instance. yes, that one. the whole page is one struct and its little family of members, and honestly? she ate. 🫶

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✨ NAME ✨

struct p9_trans_rdma — RDMA transport instance, no cap 💖

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🌸 SYNOPSIS 🌸

here's the whole vibe, membrane by membrane, exactly as written — do not come for me if you think a field is missing, this is the full list fr fr:

struct p9_trans_rdma {
    enum {
      P9_RDMA_INIT,
      P9_RDMA_ADDR_RESOLVED,
      P9_RDMA_ROUTE_RESOLVED,
      P9_RDMA_CONNECTED,
      P9_RDMA_FLUSHING,
      P9_RDMA_CLOSING,
      P9_RDMA_CLOSED,
    } state;
    struct rdma_cm_id *cm_id;
    struct ib_pd *pd;
    struct ib_qp *qp;
    struct ib_cq *cq;
    long timeout;
    bool privport;
    u16 port;
    int sq_depth;
    struct semaphore sq_sem;
    int rq_depth;
    struct semaphore rq_sem;
    atomic_t excess_rc;
    struct sockaddr_in addr;
    spinlock_t req_lock;
    struct completion cm_done;
 };

like, look at that enum. seven little states, living their best lives. 👑

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🦋 Members 🦋

so here's the cast, one iconic member at a time — bestie, take notes:

• state — tracks the transport state machine for connection setup and tear down. it's giving main character energy, honestly, because she's the one holding the whole lifecycle together 💅
• cm_id — The RDMA CM ID 🔥
• pd — Protection Domain pointer ✨
• qp — Queue Pair pointer 🎀
• cq — Completion Queue pointer 🌸
• timeout — Number of uSecs to wait for connection management events. yes, uSecs. microseconds. she's impatient, respect it 😭
• privport — Whether a privileged port may be used 👑
• port — The port to use 🔌
• sq_depth — The depth of the Send Queue 📤
• sq_sem — Semaphore for the SQ 🔐
• rq_depth — The depth of the Receive Queue. 📥
• rq_sem — Semaphore for the RQ 🔐
• excess_rc — Amount of posted Receive Contexts without a pending request. basically the leftovers pile 🍓 — and note it says See rdma_request, so like, go look at rdma_request if you want the full lore, i don't make the rules 💀
• addr — The remote peer's address 🌈
• req_lock — Protects the active request list 🛡️ like a bouncer for the req list, periodt
• cm_done — Completion event for connection management tracking ✅

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🫶 quick vibe check: excess_rc is literally defined by pointing you at rdma_request, so that's not me being vague, that's the manual being mysterious. iconic of it.

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🧚 SEE ALSO 🧚

go read these next, they're the rest of the friend group 💜 — and they all live in the Kernel file ./net/9p/trans_rdma.c:

• struct p9_rdma_context(9)
• alloc_rdma(9)
• rdma_create_trans(9)
• p9_trans_rdma_init(9)

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and that's the page!! mwah 💋 this lil fandom lives at ./net/9p and the version stamp says October 2026 — so like, slightly future-dated, very mysterious, very slay. see you in the next man page, bestie 🌟💖