diff options
| -rw-r--r-- | include/linux/sunrpc/xprt.h | 3 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 64 | ||||
| -rw-r--r-- | net/sunrpc/xprtsock.c | 2 |
3 files changed, 57 insertions, 12 deletions
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index ac08e99a81cb..eee1c6877851 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -132,6 +132,7 @@ struct rpc_xprt; struct rpc_xprt_ops { void (*set_buffer_size)(struct rpc_xprt *xprt); + int (*reserve_xprt)(struct rpc_task *task); void (*connect)(struct rpc_task *task); int (*send_request)(struct rpc_task *task); void (*set_retrans_timeout)(struct rpc_task *task); @@ -232,6 +233,8 @@ void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long */ void xprt_connect(struct rpc_task *task); void xprt_reserve(struct rpc_task *task); +int xprt_reserve_xprt(struct rpc_task *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); int xprt_adjust_timeout(struct rpc_rqst *req); diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 1ac2fbe05102..2d1e8b83dd68 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -64,14 +64,56 @@ static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); static int xprt_clear_backlog(struct rpc_xprt *xprt); +/** + * xprt_reserve_xprt - serialize write access to transports + * @task: task that is requesting access to the transport + * + * This prevents mixing the payload of separate requests, and prevents + * transport connects from colliding with writes. No congestion control + * is provided. + */ +int xprt_reserve_xprt(struct rpc_task *task) +{ + struct rpc_xprt *xprt = task->tk_xprt; + struct rpc_rqst *req = task->tk_rqstp; + + if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { + if (task == xprt->snd_task) + return 1; + if (task == NULL) + return 0; + goto out_sleep; + } + xprt->snd_task = task; + if (req) { + req->rq_bytes_sent = 0; + req->rq_ntrans++; + } + return 1; + +out_sleep: + dprintk("RPC: %4d failed to lock transport %p\n", + task->tk_pid, xprt); + task->tk_timeout = 0; + task->tk_status = -EAGAIN; + if (req && req->rq_ntrans) + rpc_sleep_on(&xprt->resend, task, NULL, NULL); + else + rpc_sleep_on(&xprt->sending, task, NULL, NULL); + return 0; +} + /* - * Serialize write access to transports, in order to prevent different - * requests from interfering with each other. - * Also prevents transport connects from colliding with writes. + * xprt_reserve_xprt_cong - serialize write access to transports + * @task: task that is requesting access to the transport + * + * Same as xprt_reserve_xprt, but Van Jacobson congestion control is + * integrated into the decision of whether a request is allowed to be + * woken up and given access to the transport. */ -static int -__xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) +int xprt_reserve_xprt_cong(struct rpc_task *task) { + struct rpc_xprt *xprt = task->tk_xprt; struct rpc_rqst *req = task->tk_rqstp; if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { @@ -79,7 +121,7 @@ __xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) return 1; goto out_sleep; } - if (xprt->nocong || __xprt_get_cong(xprt, task)) { + if (__xprt_get_cong(xprt, task)) { xprt->snd_task = task; if (req) { req->rq_bytes_sent = 0; @@ -101,20 +143,18 @@ out_sleep: return 0; } -static inline int -xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) +static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) { int retval; spin_lock_bh(&xprt->transport_lock); - retval = __xprt_lock_write(xprt, task); + retval = xprt->ops->reserve_xprt(task); spin_unlock_bh(&xprt->transport_lock); return retval; } -static void -__xprt_lock_write_next(struct rpc_xprt *xprt) +static void __xprt_lock_write_next(struct rpc_xprt *xprt) { struct rpc_task *task; @@ -598,7 +638,7 @@ int xprt_prepare_transmit(struct rpc_task *task) err = req->rq_received; goto out_unlock; } - if (!__xprt_lock_write(xprt, task)) { + if (!xprt->ops->reserve_xprt(task)) { err = -EAGAIN; goto out_unlock; } diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 79433ffd1df0..fc4fbe8ea346 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1045,6 +1045,7 @@ static void xs_connect(struct rpc_task *task) static struct rpc_xprt_ops xs_udp_ops = { .set_buffer_size = xs_udp_set_buffer_size, + .reserve_xprt = xprt_reserve_xprt_cong, .connect = xs_connect, .send_request = xs_udp_send_request, .set_retrans_timeout = xprt_set_retrans_timeout_rtt, @@ -1054,6 +1055,7 @@ static struct rpc_xprt_ops xs_udp_ops = { static struct rpc_xprt_ops xs_tcp_ops = { .set_buffer_size = xs_tcp_set_buffer_size, + .reserve_xprt = xprt_reserve_xprt, .connect = xs_connect, .send_request = xs_tcp_send_request, .set_retrans_timeout = xprt_set_retrans_timeout_def, |