diff options
| -rw-r--r-- | include/linux/sunrpc/xprt.h | 2 | ||||
| -rw-r--r-- | net/sunrpc/clnt.c | 5 | ||||
| -rw-r--r-- | net/sunrpc/xprt.c | 128 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/backchannel.c | 3 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/transport.c | 3 | ||||
| -rw-r--r-- | net/sunrpc/xprtsock.c | 4 |
6 files changed, 109 insertions, 36 deletions
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index e377620b9744..0d0cc127615e 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -397,6 +397,7 @@ void xprt_complete_rqst(struct rpc_task *task, int copied); void xprt_pin_rqst(struct rpc_rqst *req); void xprt_unpin_rqst(struct rpc_rqst *req); void xprt_release_rqst_cong(struct rpc_task *task); +bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req); void xprt_disconnect_done(struct rpc_xprt *xprt); void xprt_force_disconnect(struct rpc_xprt *xprt); void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); @@ -415,6 +416,7 @@ void xprt_unlock_connect(struct rpc_xprt *, void *); #define XPRT_BINDING (5) #define XPRT_CLOSING (6) #define XPRT_CONGESTED (9) +#define XPRT_CWND_WAIT (10) static inline void xprt_set_connected(struct rpc_xprt *xprt) { diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 8dc3d33827c4..f03911f84953 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1996,6 +1996,11 @@ call_transmit_status(struct rpc_task *task) dprint_status(task); xprt_end_transmit(task); break; + case -EBADSLT: + xprt_end_transmit(task); + task->tk_action = call_transmit; + task->tk_status = 0; + break; case -EBADMSG: xprt_end_transmit(task); task->tk_status = 0; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 44d0eeaddaac..b03355ae7b16 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -68,8 +68,6 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net); static __be32 xprt_alloc_xid(struct rpc_xprt *xprt); static void xprt_connect_status(struct rpc_task *task); -static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); -static void __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *); static void xprt_destroy(struct rpc_xprt *xprt); static DEFINE_SPINLOCK(xprt_list_lock); @@ -221,6 +219,31 @@ static void xprt_clear_locked(struct rpc_xprt *xprt) queue_work(xprtiod_workqueue, &xprt->task_cleanup); } +static bool +xprt_need_congestion_window_wait(struct rpc_xprt *xprt) +{ + return test_bit(XPRT_CWND_WAIT, &xprt->state); +} + +static void +xprt_set_congestion_window_wait(struct rpc_xprt *xprt) +{ + if (!list_empty(&xprt->xmit_queue)) { + /* Peek at head of queue to see if it can make progress */ + if (list_first_entry(&xprt->xmit_queue, struct rpc_rqst, + rq_xmit)->rq_cong) + return; + } + set_bit(XPRT_CWND_WAIT, &xprt->state); +} + +static void +xprt_test_and_clear_congestion_window_wait(struct rpc_xprt *xprt) +{ + if (!RPCXPRT_CONGESTED(xprt)) + clear_bit(XPRT_CWND_WAIT, &xprt->state); +} + /* * xprt_reserve_xprt_cong - serialize write access to transports * @task: task that is requesting access to the transport @@ -228,6 +251,7 @@ static void xprt_clear_locked(struct rpc_xprt *xprt) * 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. + * Note that the lock is only granted if we know there are free slots. */ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) { @@ -243,14 +267,12 @@ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) xprt->snd_task = task; return 1; } - if (__xprt_get_cong(xprt, task)) { + if (!xprt_need_congestion_window_wait(xprt)) { xprt->snd_task = task; return 1; } xprt_clear_locked(xprt); out_sleep: - if (req) - __xprt_put_cong(xprt, req); dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); task->tk_timeout = 0; task->tk_status = -EAGAIN; @@ -294,32 +316,14 @@ static void __xprt_lock_write_next(struct rpc_xprt *xprt) xprt_clear_locked(xprt); } -static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data) -{ - struct rpc_xprt *xprt = data; - struct rpc_rqst *req; - - req = task->tk_rqstp; - if (req == NULL) { - xprt->snd_task = task; - return true; - } - if (__xprt_get_cong(xprt, task)) { - xprt->snd_task = task; - req->rq_ntrans++; - return true; - } - return false; -} - static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) { if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) return; - if (RPCXPRT_CONGESTED(xprt)) + if (xprt_need_congestion_window_wait(xprt)) goto out_unlock; if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, - __xprt_lock_write_cong_func, xprt)) + __xprt_lock_write_func, xprt)) return; out_unlock: xprt_clear_locked(xprt); @@ -370,16 +374,16 @@ static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *ta * overflowed. Put the task to sleep if this is the case. */ static int -__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) +__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) { - struct rpc_rqst *req = task->tk_rqstp; - if (req->rq_cong) return 1; dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", - task->tk_pid, xprt->cong, xprt->cwnd); - if (RPCXPRT_CONGESTED(xprt)) + req->rq_task->tk_pid, xprt->cong, xprt->cwnd); + if (RPCXPRT_CONGESTED(xprt)) { + xprt_set_congestion_window_wait(xprt); return 0; + } req->rq_cong = 1; xprt->cong += RPC_CWNDSCALE; return 1; @@ -396,10 +400,32 @@ __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) return; req->rq_cong = 0; xprt->cong -= RPC_CWNDSCALE; + xprt_test_and_clear_congestion_window_wait(xprt); __xprt_lock_write_next_cong(xprt); } /** + * xprt_request_get_cong - Request congestion control credits + * @xprt: pointer to transport + * @req: pointer to RPC request + * + * Useful for transports that require congestion control. + */ +bool +xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) +{ + bool ret = false; + + if (req->rq_cong) + return true; + spin_lock_bh(&xprt->transport_lock); + ret = __xprt_get_cong(xprt, req) != 0; + spin_unlock_bh(&xprt->transport_lock); + return ret; +} +EXPORT_SYMBOL_GPL(xprt_request_get_cong); + +/** * xprt_release_rqst_cong - housekeeping when request is complete * @task: RPC request that recently completed * @@ -413,6 +439,20 @@ void xprt_release_rqst_cong(struct rpc_task *task) } EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); +/* + * Clear the congestion window wait flag and wake up the next + * entry on xprt->sending + */ +static void +xprt_clear_congestion_window_wait(struct rpc_xprt *xprt) +{ + if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state)) { + spin_lock_bh(&xprt->transport_lock); + __xprt_lock_write_next_cong(xprt); + spin_unlock_bh(&xprt->transport_lock); + } +} + /** * xprt_adjust_cwnd - adjust transport congestion window * @xprt: pointer to xprt @@ -1058,12 +1098,28 @@ xprt_request_enqueue_transmit(struct rpc_task *task) if (xprt_request_need_enqueue_transmit(task, req)) { spin_lock(&xprt->queue_lock); - list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { - if (pos->rq_task->tk_owner != task->tk_owner) - continue; - list_add_tail(&req->rq_xmit2, &pos->rq_xmit2); - INIT_LIST_HEAD(&req->rq_xmit); - goto out; + /* + * Requests that carry congestion control credits are added + * to the head of the list to avoid starvation issues. + */ + if (req->rq_cong) { + xprt_clear_congestion_window_wait(xprt); + list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { + if (pos->rq_cong) + continue; + /* Note: req is added _before_ pos */ + list_add_tail(&req->rq_xmit, &pos->rq_xmit); + INIT_LIST_HEAD(&req->rq_xmit2); + goto out; + } + } else { + list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { + if (pos->rq_task->tk_owner != task->tk_owner) + continue; + list_add_tail(&req->rq_xmit2, &pos->rq_xmit2); + INIT_LIST_HEAD(&req->rq_xmit); + goto out; + } } list_add_tail(&req->rq_xmit, &xprt->xmit_queue); INIT_LIST_HEAD(&req->rq_xmit2); diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index ed58761e6b23..e7c445cee16f 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -200,6 +200,9 @@ int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst) if (!xprt_connected(rqst->rq_xprt)) goto drop_connection; + if (!xprt_request_get_cong(rqst->rq_xprt, rqst)) + return -EBADSLT; + rc = rpcrdma_bc_marshal_reply(rqst); if (rc < 0) goto failed_marshal; diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index fa684bf4d090..9ff322e53f37 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -721,6 +721,9 @@ xprt_rdma_send_request(struct rpc_rqst *rqst, struct rpc_task *task) if (!xprt_connected(xprt)) goto drop_connection; + if (!xprt_request_get_cong(xprt, rqst)) + return -EBADSLT; + rc = rpcrdma_marshal_req(r_xprt, rqst); if (rc < 0) goto failed_marshal; diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index b8143eded4af..8831e84a058a 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -609,6 +609,10 @@ static int xs_udp_send_request(struct rpc_rqst *req, struct rpc_task *task) if (!xprt_bound(xprt)) return -ENOTCONN; + + if (!xprt_request_get_cong(xprt, req)) + return -EBADSLT; + req->rq_xtime = ktime_get(); status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen, xdr, 0, true, &sent); |