From ce7c252a8c741aba7c38f817b86e34361f561e42 Mon Sep 17 00:00:00 2001 From: Trond Myklebust <trond.myklebust@primarydata.com> Date: Wed, 16 Aug 2017 15:30:35 -0400 Subject: SUNRPC: Add a separate spinlock to protect the RPC request receive list This further reduces contention with the transport_lock, and allows us to convert to using a non-bh-safe spinlock, since the list is now never accessed from a bh context. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> --- include/linux/sunrpc/xprt.h | 1 + net/sunrpc/svcsock.c | 6 +++--- net/sunrpc/xprt.c | 20 ++++++++++++-------- net/sunrpc/xprtrdma/rpc_rdma.c | 8 ++++---- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 7 +++++-- net/sunrpc/xprtsock.c | 30 ++++++++++++++++-------------- 6 files changed, 41 insertions(+), 31 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 65b9e02..a97e6de 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -232,6 +232,7 @@ struct rpc_xprt { */ spinlock_t transport_lock; /* lock transport info */ spinlock_t reserve_lock; /* lock slot table */ + spinlock_t recv_lock; /* lock receive list */ u32 xid; /* Next XID value to use */ struct rpc_task * snd_task; /* Task blocked in send */ struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 2b720fa..272063c 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1001,7 +1001,7 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) if (!bc_xprt) return -EAGAIN; - spin_lock_bh(&bc_xprt->transport_lock); + spin_lock(&bc_xprt->recv_lock); req = xprt_lookup_rqst(bc_xprt, xid); if (!req) goto unlock_notfound; @@ -1019,7 +1019,7 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) memcpy(dst->iov_base, src->iov_base, src->iov_len); xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len); rqstp->rq_arg.len = 0; - spin_unlock_bh(&bc_xprt->transport_lock); + spin_unlock(&bc_xprt->recv_lock); return 0; unlock_notfound: printk(KERN_NOTICE @@ -1028,7 +1028,7 @@ unlock_notfound: __func__, ntohl(calldir), bc_xprt, ntohl(xid)); unlock_eagain: - spin_unlock_bh(&bc_xprt->transport_lock); + spin_unlock(&bc_xprt->recv_lock); return -EAGAIN; } diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 3eb9ec1..2af189c 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -872,17 +872,17 @@ void xprt_unpin_rqst(struct rpc_rqst *req) } static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req) -__must_hold(&req->rq_xprt->transport_lock) +__must_hold(&req->rq_xprt->recv_lock) { struct rpc_task *task = req->rq_task; if (task && test_bit(RPC_TASK_MSG_RECV, &task->tk_runstate)) { - spin_unlock_bh(&req->rq_xprt->transport_lock); + spin_unlock(&req->rq_xprt->recv_lock); set_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate); wait_on_bit(&task->tk_runstate, RPC_TASK_MSG_RECV, TASK_UNINTERRUPTIBLE); clear_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate); - spin_lock_bh(&req->rq_xprt->transport_lock); + spin_lock(&req->rq_xprt->recv_lock); } } @@ -1008,13 +1008,13 @@ void xprt_transmit(struct rpc_task *task) /* * Add to the list only if we're expecting a reply */ - spin_lock_bh(&xprt->transport_lock); /* Update the softirq receive buffer */ memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(req->rq_private_buf)); /* Add request to the receive list */ + spin_lock(&xprt->recv_lock); list_add_tail(&req->rq_list, &xprt->recv); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); xprt_reset_majortimeo(req); /* Turn off autodisconnect */ del_singleshot_timer_sync(&xprt->timer); @@ -1329,15 +1329,18 @@ void xprt_release(struct rpc_task *task) task->tk_ops->rpc_count_stats(task, task->tk_calldata); else if (task->tk_client) rpc_count_iostats(task, task->tk_client->cl_metrics); + spin_lock(&xprt->recv_lock); + if (!list_empty(&req->rq_list)) { + list_del(&req->rq_list); + xprt_wait_on_pinned_rqst(req); + } + spin_unlock(&xprt->recv_lock); spin_lock_bh(&xprt->transport_lock); xprt->ops->release_xprt(xprt, task); if (xprt->ops->release_request) xprt->ops->release_request(task); - if (!list_empty(&req->rq_list)) - list_del(&req->rq_list); xprt->last_used = jiffies; xprt_schedule_autodisconnect(xprt); - xprt_wait_on_pinned_rqst(req); spin_unlock_bh(&xprt->transport_lock); if (req->rq_buffer) xprt->ops->buf_free(task); @@ -1361,6 +1364,7 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net) spin_lock_init(&xprt->transport_lock); spin_lock_init(&xprt->reserve_lock); + spin_lock_init(&xprt->recv_lock); INIT_LIST_HEAD(&xprt->free); INIT_LIST_HEAD(&xprt->recv); diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index ca4d6e4..dfa748a 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1051,7 +1051,7 @@ rpcrdma_reply_handler(struct work_struct *work) * RPC completion while holding the transport lock to ensure * the rep, rqst, and rq_task pointers remain stable. */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); rqst = xprt_lookup_rqst(xprt, headerp->rm_xid); if (!rqst) goto out_norqst; @@ -1136,7 +1136,7 @@ out: xprt_release_rqst_cong(rqst->rq_task); xprt_complete_rqst(rqst->rq_task, status); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n", __func__, xprt, rqst, status); return; @@ -1187,12 +1187,12 @@ out_rdmaerr: r_xprt->rx_stats.bad_reply_count++; goto out; -/* The req was still available, but by the time the transport_lock +/* The req was still available, but by the time the recv_lock * was acquired, the rqst and task had been released. Thus the RPC * has already been terminated. */ out_norqst: - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); rpcrdma_buffer_put(req); dprintk("RPC: %s: race, no rqst left for req %p\n", __func__, req); diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index c676ed0..0d574cd 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -52,7 +52,7 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp, if (src->iov_len < 24) goto out_shortreply; - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); req = xprt_lookup_rqst(xprt, xid); if (!req) goto out_notfound; @@ -69,17 +69,20 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp, else if (credits > r_xprt->rx_buf.rb_bc_max_requests) credits = r_xprt->rx_buf.rb_bc_max_requests; + spin_lock_bh(&xprt->transport_lock); cwnd = xprt->cwnd; xprt->cwnd = credits << RPC_CWNDSHIFT; if (xprt->cwnd > cwnd) xprt_release_rqst_cong(req->rq_task); + spin_unlock_bh(&xprt->transport_lock); + ret = 0; xprt_complete_rqst(req->rq_task, rcvbuf->len); rcvbuf->len = 0; out_unlock: - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); out: return ret; diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index a344bea..2b91813 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -969,12 +969,12 @@ static void xs_local_data_read_skb(struct rpc_xprt *xprt, return; /* Look up and lock the request corresponding to the given XID */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); rovr = xprt_lookup_rqst(xprt, *xp); if (!rovr) goto out_unlock; xprt_pin_rqst(rovr); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); task = rovr->rq_task; copied = rovr->rq_private_buf.buflen; @@ -983,16 +983,16 @@ static void xs_local_data_read_skb(struct rpc_xprt *xprt, if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) { dprintk("RPC: sk_buff copy failed\n"); - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); goto out_unpin; } - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); xprt_complete_rqst(task, copied); out_unpin: xprt_unpin_rqst(rovr); out_unlock: - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); } static void xs_local_data_receive(struct sock_xprt *transport) @@ -1055,12 +1055,12 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt, return; /* Look up and lock the request corresponding to the given XID */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); rovr = xprt_lookup_rqst(xprt, *xp); if (!rovr) goto out_unlock; xprt_pin_rqst(rovr); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); task = rovr->rq_task; if ((copied = rovr->rq_private_buf.buflen) > repsize) @@ -1069,7 +1069,7 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt, /* Suck it into the iovec, verify checksum if not done by hw. */ if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) { __UDPX_INC_STATS(sk, UDP_MIB_INERRORS); - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); goto out_unpin; } @@ -1077,11 +1077,13 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt, spin_lock_bh(&xprt->transport_lock); xprt_adjust_cwnd(xprt, task, copied); + spin_unlock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); xprt_complete_rqst(task, copied); out_unpin: xprt_unpin_rqst(rovr); out_unlock: - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); } static void xs_udp_data_receive(struct sock_xprt *transport) @@ -1344,24 +1346,24 @@ static inline int xs_tcp_read_reply(struct rpc_xprt *xprt, dprintk("RPC: read reply XID %08x\n", ntohl(transport->tcp_xid)); /* Find and lock the request corresponding to this xid */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); req = xprt_lookup_rqst(xprt, transport->tcp_xid); if (!req) { dprintk("RPC: XID %08x request not found!\n", ntohl(transport->tcp_xid)); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); return -1; } xprt_pin_rqst(req); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); xs_tcp_read_common(xprt, desc, req); - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->recv_lock); if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) xprt_complete_rqst(req->rq_task, transport->tcp_copied); xprt_unpin_rqst(req); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->recv_lock); return 0; } -- cgit v1.1