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path: root/net/sunrpc/xprtrdma/backchannel.c
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Diffstat (limited to 'net/sunrpc/xprtrdma/backchannel.c')
-rw-r--r--net/sunrpc/xprtrdma/backchannel.c71
1 files changed, 27 insertions, 44 deletions
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 03f6b5840764..d31d0ac5ada9 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -49,6 +49,7 @@ static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt,
if (IS_ERR(rb))
goto out_fail;
req->rl_rdmabuf = rb;
+ xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
size = r_xprt->rx_data.inline_rsize;
rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, GFP_KERNEL);
@@ -202,20 +203,24 @@ size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt)
*/
int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
{
- struct rpc_xprt *xprt = rqst->rq_xprt;
- struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
- struct rpcrdma_msg *headerp;
-
- headerp = rdmab_to_msg(req->rl_rdmabuf);
- headerp->rm_xid = rqst->rq_xid;
- headerp->rm_vers = rpcrdma_version;
- headerp->rm_credit =
- cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_max_requests);
- headerp->rm_type = rdma_msg;
- headerp->rm_body.rm_chunks[0] = xdr_zero;
- headerp->rm_body.rm_chunks[1] = xdr_zero;
- headerp->rm_body.rm_chunks[2] = xdr_zero;
+ __be32 *p;
+
+ rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
+ xdr_init_encode(&req->rl_stream, &req->rl_hdrbuf,
+ req->rl_rdmabuf->rg_base);
+
+ p = xdr_reserve_space(&req->rl_stream, 28);
+ if (unlikely(!p))
+ return -EIO;
+ *p++ = rqst->rq_xid;
+ *p++ = rpcrdma_version;
+ *p++ = cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_max_requests);
+ *p++ = rdma_msg;
+ *p++ = xdr_zero;
+ *p++ = xdr_zero;
+ *p = xdr_zero;
if (!rpcrdma_prepare_send_sges(&r_xprt->rx_ia, req, RPCRDMA_HDRLEN_MIN,
&rqst->rq_snd_buf, rpcrdma_noch))
@@ -271,9 +276,6 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
* @xprt: transport receiving the call
* @rep: receive buffer containing the call
*
- * Called in the RPC reply handler, which runs in a tasklet.
- * Be quick about it.
- *
* Operational assumptions:
* o Backchannel credits are ignored, just as the NFS server
* forechannel currently does
@@ -284,7 +286,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_rep *rep)
{
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
- struct rpcrdma_msg *headerp;
struct svc_serv *bc_serv;
struct rpcrdma_req *req;
struct rpc_rqst *rqst;
@@ -292,24 +293,15 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
size_t size;
__be32 *p;
- headerp = rdmab_to_msg(rep->rr_rdmabuf);
+ p = xdr_inline_decode(&rep->rr_stream, 0);
+ size = xdr_stream_remaining(&rep->rr_stream);
+
#ifdef RPCRDMA_BACKCHANNEL_DEBUG
pr_info("RPC: %s: callback XID %08x, length=%u\n",
- __func__, be32_to_cpu(headerp->rm_xid), rep->rr_len);
- pr_info("RPC: %s: %*ph\n", __func__, rep->rr_len, headerp);
+ __func__, be32_to_cpup(p), size);
+ pr_info("RPC: %s: %*ph\n", __func__, size, p);
#endif
- /* Sanity check:
- * Need at least enough bytes for RPC/RDMA header, as code
- * here references the header fields by array offset. Also,
- * backward calls are always inline, so ensure there
- * are some bytes beyond the RPC/RDMA header.
- */
- if (rep->rr_len < RPCRDMA_HDRLEN_MIN + 24)
- goto out_short;
- p = (__be32 *)((unsigned char *)headerp + RPCRDMA_HDRLEN_MIN);
- size = rep->rr_len - RPCRDMA_HDRLEN_MIN;
-
/* Grab a free bc rqst */
spin_lock(&xprt->bc_pa_lock);
if (list_empty(&xprt->bc_pa_list)) {
@@ -325,7 +317,7 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
/* Prepare rqst */
rqst->rq_reply_bytes_recvd = 0;
rqst->rq_bytes_sent = 0;
- rqst->rq_xid = headerp->rm_xid;
+ rqst->rq_xid = *p;
rqst->rq_private_buf.len = size;
set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
@@ -337,9 +329,9 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
buf->len = size;
/* The receive buffer has to be hooked to the rpcrdma_req
- * so that it can be reposted after the server is done
- * parsing it but just before sending the backward
- * direction reply.
+ * so that it is not released while the req is pointing
+ * to its buffer, and so that it can be reposted after
+ * the Upper Layer is done decoding it.
*/
req = rpcr_to_rdmar(rqst);
dprintk("RPC: %s: attaching rep %p to req %p\n",
@@ -367,13 +359,4 @@ out_overflow:
* when the connection is re-established.
*/
return;
-
-out_short:
- pr_warn("RPC/RDMA short backward direction call\n");
-
- if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, rep))
- xprt_disconnect_done(xprt);
- else
- pr_warn("RPC: %s: reposting rep %p\n",
- __func__, rep);
}