Replace C-structure-based XDR encoding with pointer-based,
which is more portable, and more idiomatic.
Add appropriate documenting comment.
rpc_xprt is used only to derive rpcrdma_xprt, which the
caller already has. Pass that directly instead.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 63 ++++++++++++++++++++++-----------------
net/sunrpc/xprtrdma/transport.c | 2 +
net/sunrpc/xprtrdma/xprt_rdma.h | 2 +
3 files changed, 38 insertions(+), 29 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index a044be2..103491e 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -651,37 +651,46 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
req->rl_mapped_sges = 0;
}
-/*
- * Marshal a request: the primary job of this routine is to choose
- * the transfer modes. See comments below.
+/**
+ * rpcrdma_marshal_req - Marshal and send one RPC request
+ * @r_xprt: controlling transport
+ * @rqst: RPC request to be marshaled
*
- * Returns zero on success, otherwise a negative errno.
+ * For the RPC in "rqst", this function:
+ * - Chooses the transfer mode (eg., RDMA_MSG or RDMA_NOMSG)
+ * - Registers Read, Write, and Reply chunks
+ * - Constructs the transport header
+ * - Posts a Send WR to send the transport header and request
+ *
+ * Returns:
+ * 0: the RPC was sent successfully
+ * ENOTCONN: the connection was lost
+ * EAGAIN: no pages are available for on-demand reply buffer
+ * ENOBUFS: no MRs are available to register chunks
+ * EIO: a permanent problem occurred while marshaling
*/
-
int
-rpcrdma_marshal_req(struct rpc_rqst *rqst)
+rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
{
- struct rpc_xprt *xprt = rqst->rq_xprt;
- struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+ struct rpcrdma_regbuf *rb = req->rl_rdmabuf;
enum rpcrdma_chunktype rtype, wtype;
- struct rpcrdma_msg *headerp;
bool ddp_allowed;
ssize_t hdrlen;
size_t rpclen;
- __be32 *iptr;
+ __be32 *p;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
return rpcrdma_bc_marshal_reply(rqst);
#endif
- headerp = rdmab_to_msg(req->rl_rdmabuf);
+ p = rb->rg_base;
/* don't byte-swap XID, it's already done in request */
- headerp->rm_xid = rqst->rq_xid;
- headerp->rm_vers = rpcrdma_version;
- headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests);
- headerp->rm_type = rdma_msg;
+ *p++ = rqst->rq_xid;
+ *p++ = rpcrdma_version;
+ *p++ = cpu_to_be32(r_xprt->rx_buf.rb_max_requests);
+ *p = rdma_msg;
/* When the ULP employs a GSS flavor that guarantees integrity
* or privacy, direct data placement of individual data items
@@ -729,7 +738,7 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
rqst->rq_snd_buf.tail[0].iov_len;
} else {
r_xprt->rx_stats.nomsg_call_count++;
- headerp->rm_type = htonl(RDMA_NOMSG);
+ *p = rdma_nomsg;
rtype = rpcrdma_areadch;
rpclen = 0;
}
@@ -756,17 +765,17 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
* send a Call message with a Position Zero Read chunk and a
* regular Read chunk at the same time.
*/
- iptr = headerp->rm_body.rm_chunks;
- iptr = rpcrdma_encode_read_list(r_xprt, req, rqst, iptr, rtype);
- if (IS_ERR(iptr))
+ p++;
+ p = rpcrdma_encode_read_list(r_xprt, req, rqst, p, rtype);
+ if (IS_ERR(p))
goto out_err;
- iptr = rpcrdma_encode_write_list(r_xprt, req, rqst, iptr, wtype);
- if (IS_ERR(iptr))
+ p = rpcrdma_encode_write_list(r_xprt, req, rqst, p, wtype);
+ if (IS_ERR(p))
goto out_err;
- iptr = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, iptr, wtype);
- if (IS_ERR(iptr))
+ p = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, p, wtype);
+ if (IS_ERR(p))
goto out_err;
- hdrlen = (unsigned char *)iptr - (unsigned char *)headerp;
+ hdrlen = (unsigned char *)p - (unsigned char *)rb->rg_base;
dprintk("RPC: %5u %s: %s/%s: hdrlen %zd rpclen %zd\n",
rqst->rq_task->tk_pid, __func__,
@@ -775,16 +784,16 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
if (!rpcrdma_prepare_send_sges(&r_xprt->rx_ia, req, hdrlen,
&rqst->rq_snd_buf, rtype)) {
- iptr = ERR_PTR(-EIO);
+ p = ERR_PTR(-EIO);
goto out_err;
}
return 0;
out_err:
pr_err("rpcrdma: rpcrdma_marshal_req failed, status %ld\n",
- PTR_ERR(iptr));
+ PTR_ERR(p));
r_xprt->rx_stats.failed_marshal_count++;
- return PTR_ERR(iptr);
+ return PTR_ERR(p);
}
/*
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index c717f54..26c9a19 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -689,7 +689,7 @@
if (unlikely(!list_empty(&req->rl_registered)))
r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
- rc = rpcrdma_marshal_req(rqst);
+ rc = rpcrdma_marshal_req(r_xprt, rqst);
if (rc < 0)
goto failed_marshal;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 171a351..e6d76a0 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -586,7 +586,7 @@ enum rpcrdma_chunktype {
bool rpcrdma_prepare_send_sges(struct rpcrdma_ia *, struct rpcrdma_req *,
u32, struct xdr_buf *, enum rpcrdma_chunktype);
void rpcrdma_unmap_sges(struct rpcrdma_ia *, struct rpcrdma_req *);
-int rpcrdma_marshal_req(struct rpc_rqst *);
+int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
void rpcrdma_reply_handler(struct work_struct *work);
--
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