Return-Path: Received: from mail-it0-f67.google.com ([209.85.214.67]:40283 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727465AbeICWLG (ORCPT ); Mon, 3 Sep 2018 18:11:06 -0400 Received: by mail-it0-f67.google.com with SMTP id h23-v6so1851776ita.5 for ; Mon, 03 Sep 2018 10:49:52 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: [PATCH 20/27] SUNRPC: Treat the task and request as separate in the xprt_ops->send_request() From: Chuck Lever In-Reply-To: <0b84ef010e4b3e4d156b6b7ac60c5fb0c2a48627.camel@gmail.com> Date: Mon, 3 Sep 2018 13:49:50 -0400 Cc: Linux NFS Mailing List Message-Id: <4CBB86A7-C070-468C-A36E-2B586BEBD952@gmail.com> References: <20180903152936.24325-1-trond.myklebust@hammerspace.com> <20180903152936.24325-2-trond.myklebust@hammerspace.com> <20180903152936.24325-3-trond.myklebust@hammerspace.com> <20180903152936.24325-4-trond.myklebust@hammerspace.com> <20180903152936.24325-5-trond.myklebust@hammerspace.com> <20180903152936.24325-6-trond.myklebust@hammerspace.com> <20180903152936.24325-7-trond.myklebust@hammerspace.com> <20180903152936.24325-8-trond.myklebust@hammerspace.com> <20180903152936.24325-9-trond.myklebust@hammerspace.com> <20180903152936.24325-10-trond.myklebust@hammerspace.com> <20180903152936.24325-11-trond.myklebust@hammerspace.com> <20180903152936.24325-12-trond.myklebust@hammerspace.com> <20180903152936.24325-13-trond.myklebust@hammerspace.com> <20180903152936.24325-14-trond.myklebust@hammerspace.com> <20180903152936.24325-15-trond.myklebust@hammerspace.com> <20180903152936.24325-16-trond.myklebust@hammerspace.com> <20180903152936.24325-17-trond.myklebust@hammerspace.com> <20180903152936.24325-18-trond.myklebust@hammerspace.com> <20180903152936.24325-19-trond.myklebust@hammerspace.com> <20180903152936.24325-20-trond.myklebust@hammerspace.com> <20180903152936.24325-21-trond.myklebust@hammerspace.com> <0b84ef010e4b3e4d156b6b7ac60c5fb0c2a48627.camel@gmail.com> To: Trond Myklebust Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Sep 3, 2018, at 1:47 PM, Trond Myklebust wrote: > > On Mon, 2018-09-03 at 13:28 -0400, Chuck Lever wrote: >>> On Sep 3, 2018, at 11:29 AM, Trond Myklebust >>> wrote: >>> >>> When we shift to using the transmit queue, then the task that holds >>> the >>> write lock will not necessarily be the same as the one being >>> transmitted. >> >> Can you pass in just the rpc_rqst? Then @task would be available as >> xprt->snd_task. > > No. The point is that when we add queueing, @req->rq_task will usually > be asleep on xprt->sending. Only the task that holds the XPRT_LOCK is > awake, and so it is the one that needs to be put asleep when we hit a > socket nospace/EAGAIN error. Right, that task is rqst->rq_xprt->snd_task, isn't it? > We _could_ potentially avoid passing in the task at all, and just have > xs_nospace() put xprt->snd_task to sleep, but that would skirt the edge > of a transport layering violation. > >> >>> Signed-off-by: Trond Myklebust >>> --- >>> include/linux/sunrpc/xprt.h | 2 +- >>> net/sunrpc/xprt.c | 2 +- >>> net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 3 +-- >>> net/sunrpc/xprtrdma/transport.c | 5 ++-- >>> net/sunrpc/xprtsock.c | 27 +++++++++++------ >>> ----- >>> 5 files changed, 18 insertions(+), 21 deletions(-) >>> >>> diff --git a/include/linux/sunrpc/xprt.h >>> b/include/linux/sunrpc/xprt.h >>> index 81a6c2c8dfc7..6d91acfe0644 100644 >>> --- a/include/linux/sunrpc/xprt.h >>> +++ b/include/linux/sunrpc/xprt.h >>> @@ -140,7 +140,7 @@ struct rpc_xprt_ops { >>> void (*connect)(struct rpc_xprt *xprt, struct >>> rpc_task *task); >>> int (*buf_alloc)(struct rpc_task *task); >>> void (*buf_free)(struct rpc_task *task); >>> - int (*send_request)(struct rpc_task *task); >>> + int (*send_request)(struct rpc_rqst *req, struct >>> rpc_task *task); >>> void (*set_retrans_timeout)(struct rpc_task >>> *task); >>> void (*timer)(struct rpc_xprt *xprt, struct >>> rpc_task *task); >>> void (*release_request)(struct rpc_task *task); >>> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c >>> index defc6167570a..3efcb69af526 100644 >>> --- a/net/sunrpc/xprt.c >>> +++ b/net/sunrpc/xprt.c >>> @@ -1170,7 +1170,7 @@ void xprt_transmit(struct rpc_task *task) >>> } >>> >>> connect_cookie = xprt->connect_cookie; >>> - status = xprt->ops->send_request(task); >>> + status = xprt->ops->send_request(req, task); >>> trace_xprt_transmit(xprt, req->rq_xid, status); >>> if (status != 0) { >>> task->tk_status = status; >>> diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c >>> b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c >>> index 09b12b7568fe..d1618c70edb4 100644 >>> --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c >>> +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c >>> @@ -215,9 +215,8 @@ rpcrdma_bc_send_request(struct svcxprt_rdma >>> *rdma, struct rpc_rqst *rqst) >>> * connection. >>> */ >>> static int >>> -xprt_rdma_bc_send_request(struct rpc_task *task) >>> +xprt_rdma_bc_send_request(struct rpc_rqst *rqst, struct rpc_task >>> *task) >>> { >>> - struct rpc_rqst *rqst = task->tk_rqstp; >>> struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt; >>> struct svcxprt_rdma *rdma; >>> int ret; >>> diff --git a/net/sunrpc/xprtrdma/transport.c >>> b/net/sunrpc/xprtrdma/transport.c >>> index 143ce2579ba9..fa684bf4d090 100644 >>> --- a/net/sunrpc/xprtrdma/transport.c >>> +++ b/net/sunrpc/xprtrdma/transport.c >>> @@ -706,9 +706,8 @@ xprt_rdma_free(struct rpc_task *task) >>> * sent. Do not try to send this message again. >>> */ >>> static int >>> -xprt_rdma_send_request(struct rpc_task *task) >>> +xprt_rdma_send_request(struct rpc_rqst *rqst, struct rpc_task >>> *task) >> >> Nit: The function's documenting comment will need to be updated. >> >> >>> { >>> - struct rpc_rqst *rqst = task->tk_rqstp; >>> struct rpc_xprt *xprt = rqst->rq_xprt; >>> struct rpcrdma_req *req = rpcr_to_rdmar(rqst); >>> struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); >>> @@ -741,7 +740,7 @@ xprt_rdma_send_request(struct rpc_task *task) >>> /* An RPC with no reply will throw off credit accounting, >>> * so drop the connection to reset the credit grant. >>> */ >>> - if (!rpc_reply_expected(task)) >>> + if (!rpc_reply_expected(rqst->rq_task)) >>> goto drop_connection; >>> return 0; >>> >>> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c >>> index 8d6404259ff9..b8143eded4af 100644 >>> --- a/net/sunrpc/xprtsock.c >>> +++ b/net/sunrpc/xprtsock.c >>> @@ -449,12 +449,12 @@ static void xs_nospace_callback(struct >>> rpc_task *task) >>> >>> /** >>> * xs_nospace - place task on wait queue if transmit was incomplete >>> + * @req: pointer to RPC request >>> * @task: task to put to sleep >>> * >>> */ >>> -static int xs_nospace(struct rpc_task *task) >>> +static int xs_nospace(struct rpc_rqst *req, struct rpc_task *task) >>> { >>> - struct rpc_rqst *req = task->tk_rqstp; >>> struct rpc_xprt *xprt = req->rq_xprt; >>> struct sock_xprt *transport = container_of(xprt, struct >>> sock_xprt, xprt); >>> struct sock *sk = transport->inet; >>> @@ -513,6 +513,7 @@ static inline void >>> xs_encode_stream_record_marker(struct xdr_buf *buf) >>> >>> /** >>> * xs_local_send_request - write an RPC request to an AF_LOCAL >>> socket >>> + * @req: pointer to RPC request >>> * @task: RPC task that manages the state of an RPC request >>> * >>> * Return values: >>> @@ -522,9 +523,8 @@ static inline void >>> xs_encode_stream_record_marker(struct xdr_buf *buf) >>> * ENOTCONN: Caller needs to invoke connect logic then call >>> again >>> * other: Some other error occured, the request was not >>> sent >>> */ >>> -static int xs_local_send_request(struct rpc_task *task) >>> +static int xs_local_send_request(struct rpc_rqst *req, struct >>> rpc_task *task) >>> { >>> - struct rpc_rqst *req = task->tk_rqstp; >>> struct rpc_xprt *xprt = req->rq_xprt; >>> struct sock_xprt *transport = >>> container_of(xprt, struct sock_xprt, >>> xprt); >>> @@ -569,7 +569,7 @@ static int xs_local_send_request(struct >>> rpc_task *task) >>> case -ENOBUFS: >>> break; >>> case -EAGAIN: >>> - status = xs_nospace(task); >>> + status = xs_nospace(req, task); >>> break; >>> default: >>> dprintk("RPC: sendmsg returned unrecognized error >>> %d\n", >>> @@ -585,6 +585,7 @@ static int xs_local_send_request(struct >>> rpc_task *task) >>> >>> /** >>> * xs_udp_send_request - write an RPC request to a UDP socket >>> + * @req: pointer to RPC request >>> * @task: address of RPC task that manages the state of an RPC >>> request >>> * >>> * Return values: >>> @@ -594,9 +595,8 @@ static int xs_local_send_request(struct >>> rpc_task *task) >>> * ENOTCONN: Caller needs to invoke connect logic then call >>> again >>> * other: Some other error occurred, the request was not >>> sent >>> */ >>> -static int xs_udp_send_request(struct rpc_task *task) >>> +static int xs_udp_send_request(struct rpc_rqst *req, struct >>> rpc_task *task) >>> { >>> - struct rpc_rqst *req = task->tk_rqstp; >>> struct rpc_xprt *xprt = req->rq_xprt; >>> struct sock_xprt *transport = container_of(xprt, struct >>> sock_xprt, xprt); >>> struct xdr_buf *xdr = &req->rq_snd_buf; >>> @@ -638,7 +638,7 @@ static int xs_udp_send_request(struct rpc_task >>> *task) >>> /* Should we call xs_close() here? */ >>> break; >>> case -EAGAIN: >>> - status = xs_nospace(task); >>> + status = xs_nospace(req, task); >>> break; >>> case -ENETUNREACH: >>> case -ENOBUFS: >>> @@ -658,6 +658,7 @@ static int xs_udp_send_request(struct rpc_task >>> *task) >>> >>> /** >>> * xs_tcp_send_request - write an RPC request to a TCP socket >>> + * @req: pointer to RPC request >>> * @task: address of RPC task that manages the state of an RPC >>> request >>> * >>> * Return values: >>> @@ -670,9 +671,8 @@ static int xs_udp_send_request(struct rpc_task >>> *task) >>> * XXX: In the case of soft timeouts, should we eventually give up >>> * if sendmsg is not able to make progress? >>> */ >>> -static int xs_tcp_send_request(struct rpc_task *task) >>> +static int xs_tcp_send_request(struct rpc_rqst *req, struct >>> rpc_task *task) >>> { >>> - struct rpc_rqst *req = task->tk_rqstp; >>> struct rpc_xprt *xprt = req->rq_xprt; >>> struct sock_xprt *transport = container_of(xprt, struct >>> sock_xprt, xprt); >>> struct xdr_buf *xdr = &req->rq_snd_buf; >>> @@ -697,7 +697,7 @@ static int xs_tcp_send_request(struct rpc_task >>> *task) >>> * completes while the socket holds a reference to the pages, >>> * then we may end up resending corrupted data. >>> */ >>> - if (task->tk_flags & RPC_TASK_SENT) >>> + if (req->rq_task->tk_flags & RPC_TASK_SENT) >>> zerocopy = false; >>> >>> if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state)) >>> @@ -761,7 +761,7 @@ static int xs_tcp_send_request(struct rpc_task >>> *task) >>> /* Should we call xs_close() here? */ >>> break; >>> case -EAGAIN: >>> - status = xs_nospace(task); >>> + status = xs_nospace(req, task); >>> break; >>> case -ECONNRESET: >>> case -ECONNREFUSED: >>> @@ -2706,9 +2706,8 @@ static int bc_sendto(struct rpc_rqst *req) >>> /* >>> * The send routine. Borrows from svc_send >>> */ >>> -static int bc_send_request(struct rpc_task *task) >>> +static int bc_send_request(struct rpc_rqst *req, struct rpc_task >>> *task) >>> { >>> - struct rpc_rqst *req = task->tk_rqstp; >>> struct svc_xprt *xprt; >>> int len; >>> >>> -- >>> 2.17.1 >>> >> >> -- >> Chuck Lever >> chucklever@gmail.com >> >> >> > -- Chuck Lever chucklever@gmail.com