From: Trond Myklebust RPC: Ensure that we disconnect TCP socket when client requests error out If we're part way through transmitting a TCP request, and the client errors, then we need to disconnect and reconnect the TCP socket in order to avoid confusing the server. Signed-off-by: Trond Myklebust --- include/linux/sunrpc/xprt.h | 2 +- net/sunrpc/clnt.c | 52 ++++++++++++++++++++++++------------------- net/sunrpc/xprt.c | 21 ++--------------- net/sunrpc/xprtsock.c | 29 +++++++++++++++++++++++- 4 files changed, 61 insertions(+), 43 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index e8bbe81..840e47a 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -229,7 +229,7 @@ int xprt_reserve_xprt(struct rpc_task int xprt_reserve_xprt_cong(struct rpc_task *task); int xprt_prepare_transmit(struct rpc_task *task); void xprt_transmit(struct rpc_task *task); -void xprt_abort_transmit(struct rpc_task *task); +void xprt_end_transmit(struct rpc_task *task); int xprt_adjust_timeout(struct rpc_rqst *req); void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task); void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 4ba271f..d6409e7 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -921,26 +921,43 @@ call_transmit(struct rpc_task *task) task->tk_status = xprt_prepare_transmit(task); if (task->tk_status != 0) return; + task->tk_action = call_transmit_status; /* Encode here so that rpcsec_gss can use correct sequence number. */ if (rpc_task_need_encode(task)) { - task->tk_rqstp->rq_bytes_sent = 0; + BUG_ON(task->tk_rqstp->rq_bytes_sent != 0); call_encode(task); /* Did the encode result in an error condition? */ if (task->tk_status != 0) - goto out_nosend; + return; } - task->tk_action = call_transmit_status; xprt_transmit(task); if (task->tk_status < 0) return; - if (!task->tk_msg.rpc_proc->p_decode) { - task->tk_action = rpc_exit_task; - rpc_wake_up_task(task); - } - return; -out_nosend: - /* release socket write lock before attempting to handle error */ - xprt_abort_transmit(task); + /* + * On success, ensure that we call xprt_end_transmit() before sleeping + * in order to allow access to the socket to other RPC requests. + */ + call_transmit_status(task); + if (task->tk_msg.rpc_proc->p_decode != NULL) + return; + task->tk_action = rpc_exit_task; + rpc_wake_up_task(task); +} + +/* + * 5a. Handle cleanup after a transmission + */ +static void +call_transmit_status(struct rpc_task *task) +{ + task->tk_action = call_status; + /* + * Special case: if we've been waiting on the socket's write_space() + * callback, then don't call xprt_end_transmit(). + */ + if (task->tk_status == -EAGAIN) + return; + xprt_end_transmit(task); rpc_task_force_reencode(task); } @@ -992,18 +1009,7 @@ call_status(struct rpc_task *task) } /* - * 6a. Handle transmission errors. - */ -static void -call_transmit_status(struct rpc_task *task) -{ - if (task->tk_status != -EAGAIN) - rpc_task_force_reencode(task); - call_status(task); -} - -/* - * 6b. Handle RPC timeout + * 6a. Handle RPC timeout * We do not release the request slot, so we keep using the * same XID for all retransmits. */ diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 313b68d..e8c2bc4 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -707,12 +707,9 @@ out_unlock: return err; } -void -xprt_abort_transmit(struct rpc_task *task) +void xprt_end_transmit(struct rpc_task *task) { - struct rpc_xprt *xprt = task->tk_xprt; - - xprt_release_write(xprt, task); + xprt_release_write(task->tk_xprt, task); } /** @@ -761,8 +758,6 @@ void xprt_transmit(struct rpc_task *task task->tk_status = -ENOTCONN; else if (!req->rq_received) rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer); - - xprt->ops->release_xprt(xprt, task); spin_unlock_bh(&xprt->transport_lock); return; } @@ -772,18 +767,8 @@ void xprt_transmit(struct rpc_task *task * schedq, and being picked up by a parallel run of rpciod(). */ task->tk_status = status; - - switch (status) { - case -ECONNREFUSED: + if (status == -ECONNREFUSED) rpc_sleep_on(&xprt->sending, task, NULL, NULL); - case -EAGAIN: - case -ENOTCONN: - return; - default: - break; - } - xprt_release_write(xprt, task); - return; } static inline void do_xprt_reserve(struct rpc_task *task) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index ee678ed..441bd53 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -414,6 +414,33 @@ static int xs_tcp_send_request(struct rp } /** + * xs_tcp_release_xprt - clean up after a tcp transmission + * @xprt: transport + * @task: rpc task + * + * This cleans up if an error causes us to abort the transmission of a request. + * In this case, the socket may need to be reset in order to avoid confusing + * the server. + */ +static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) +{ + struct rpc_rqst *req; + + if (task != xprt->snd_task) + return; + if (task == NULL) + goto out_release; + req = task->tk_rqstp; + if (req->rq_bytes_sent == 0) + goto out_release; + if (req->rq_bytes_sent == req->rq_snd_buf.len) + goto out_release; + set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state); +out_release: + xprt_release_xprt(xprt, task); +} + +/** * xs_close - close a socket * @xprt: transport * @@ -1250,7 +1277,7 @@ static struct rpc_xprt_ops xs_udp_ops = static struct rpc_xprt_ops xs_tcp_ops = { .reserve_xprt = xprt_reserve_xprt, - .release_xprt = xprt_release_xprt, + .release_xprt = xs_tcp_release_xprt, .set_port = xs_set_port, .connect = xs_connect, .buf_alloc = rpc_malloc,