Clean up: The error cases in rpcrdma_reply_handler() almost never
execute. Ensure the compiler places them out of the hot path.
No behavior change expected.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Reviewed-by: Devesh Sharma <devesh.sharma@xxxxxxxxxxxxx>
Tested-By: Devesh Sharma <devesh.sharma@xxxxxxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 89 ++++++++++++++++++++++-----------------
net/sunrpc/xprtrdma/verbs.c | 2 -
net/sunrpc/xprtrdma/xprt_rdma.h | 2 +
3 files changed, 53 insertions(+), 40 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index bc8bd65..60ffa63 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -741,52 +741,27 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
unsigned long cwnd;
u32 credits;
- /* Check status. If bad, signal disconnect and return rep to pool */
- if (rep->rr_len == ~0U) {
- rpcrdma_recv_buffer_put(rep);
- if (r_xprt->rx_ep.rep_connected == 1) {
- r_xprt->rx_ep.rep_connected = -EIO;
- rpcrdma_conn_func(&r_xprt->rx_ep);
- }
- return;
- }
- if (rep->rr_len < RPCRDMA_HDRLEN_MIN) {
- dprintk("RPC: %s: short/invalid reply\n", __func__);
- goto repost;
- }
+ dprintk("RPC: %s: incoming rep %p\n", __func__, rep);
+
+ if (rep->rr_len == RPCRDMA_BAD_LEN)
+ goto out_badstatus;
+ if (rep->rr_len < RPCRDMA_HDRLEN_MIN)
+ goto out_shortreply;
+
headerp = rdmab_to_msg(rep->rr_rdmabuf);
- if (headerp->rm_vers != rpcrdma_version) {
- dprintk("RPC: %s: invalid version %d\n",
- __func__, be32_to_cpu(headerp->rm_vers));
- goto repost;
- }
+ if (headerp->rm_vers != rpcrdma_version)
+ goto out_badversion;
/* Get XID and try for a match. */
spin_lock(&xprt->transport_lock);
rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
- if (rqst == NULL) {
- spin_unlock(&xprt->transport_lock);
- dprintk("RPC: %s: reply 0x%p failed "
- "to match any request xid 0x%08x len %d\n",
- __func__, rep, be32_to_cpu(headerp->rm_xid),
- rep->rr_len);
-repost:
- r_xprt->rx_stats.bad_reply_count++;
- if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
- rpcrdma_recv_buffer_put(rep);
-
- return;
- }
+ if (!rqst)
+ goto out_nomatch;
/* get request object */
req = rpcr_to_rdmar(rqst);
- if (req->rl_reply) {
- spin_unlock(&xprt->transport_lock);
- dprintk("RPC: %s: duplicate reply 0x%p to RPC "
- "request 0x%p: xid 0x%08x\n", __func__, rep, req,
- be32_to_cpu(headerp->rm_xid));
- goto repost;
- }
+ if (req->rl_reply)
+ goto out_duplicate;
dprintk("RPC: %s: reply 0x%p completes request 0x%p\n"
" RPC request 0x%p xid 0x%08x\n",
@@ -883,8 +858,44 @@ badheader:
if (xprt->cwnd > cwnd)
xprt_release_rqst_cong(rqst->rq_task);
+ xprt_complete_rqst(rqst->rq_task, status);
+ spin_unlock(&xprt->transport_lock);
dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
__func__, xprt, rqst, status);
- xprt_complete_rqst(rqst->rq_task, status);
+ return;
+
+out_badstatus:
+ rpcrdma_recv_buffer_put(rep);
+ if (r_xprt->rx_ep.rep_connected == 1) {
+ r_xprt->rx_ep.rep_connected = -EIO;
+ rpcrdma_conn_func(&r_xprt->rx_ep);
+ }
+ return;
+
+out_shortreply:
+ dprintk("RPC: %s: short/invalid reply\n", __func__);
+ goto repost;
+
+out_badversion:
+ dprintk("RPC: %s: invalid version %d\n",
+ __func__, be32_to_cpu(headerp->rm_vers));
+ goto repost;
+
+out_nomatch:
+ spin_unlock(&xprt->transport_lock);
+ dprintk("RPC: %s: no match for incoming xid 0x%08x len %d\n",
+ __func__, be32_to_cpu(headerp->rm_xid),
+ rep->rr_len);
+ goto repost;
+
+out_duplicate:
spin_unlock(&xprt->transport_lock);
+ dprintk("RPC: %s: "
+ "duplicate reply %p to RPC request %p: xid 0x%08x\n",
+ __func__, rep, req, be32_to_cpu(headerp->rm_xid));
+
+repost:
+ r_xprt->rx_stats.bad_reply_count++;
+ if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
+ rpcrdma_recv_buffer_put(rep);
}
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index e9599e9..0076129 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -225,7 +225,7 @@ out_fail:
if (wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("RPC: %s: rep %p: %s\n",
__func__, rep, ib_wc_status_msg(wc->status));
- rep->rr_len = ~0U;
+ rep->rr_len = RPCRDMA_BAD_LEN;
goto out_schedule;
}
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 42c8d44..a13508b 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -168,6 +168,8 @@ struct rpcrdma_rep {
struct rpcrdma_regbuf *rr_rdmabuf;
};
+#define RPCRDMA_BAD_LEN (~0U)
+
/*
* struct rpcrdma_mw - external memory region metadata
*
--
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