Return-Path: Received: from mail-io0-f170.google.com ([209.85.223.170]:35619 "EHLO mail-io0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752327AbbJFO7J (ORCPT ); Tue, 6 Oct 2015 10:59:09 -0400 Subject: [PATCH v2 04/16] xprtrdma: Refactor reply handler error handling From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Tue, 06 Oct 2015 10:59:07 -0400 Message-ID: <20151006145907.11788.18646.stgit@manet.1015granger.net> In-Reply-To: <20151006142430.11788.42604.stgit@manet.1015granger.net> References: <20151006142430.11788.42604.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- 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 *