static void xprt_connect_status(struct rpc_task *task);
static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
-static int xprt_clear_backlog(struct rpc_xprt *xprt);
+/*
+ * The transport code maintains an estimate on the maximum number of out-
+ * standing RPC requests, using a smoothed version of the congestion
+ * avoidance implemented in 44BSD. This is basically the Van Jacobson
+ * congestion algorithm: If a retransmit occurs, the congestion window is
+ * halved; otherwise, it is incremented by 1/cwnd when
+ *
+ * - a reply is received and
+ * - a full number of requests are outstanding and
+ * - the congestion window hasn't been updated recently.
+ */
+#define RPC_CWNDSHIFT (8U)
+#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
+#define RPC_INITCWND RPC_CWNDSCALE
+#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
+
+#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
+
+/**
+ * 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;
+}
+
+static void xprt_clear_locked(struct rpc_xprt *xprt)
+{
+ xprt->snd_task = NULL;
+ if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) {
+ smp_mb__before_clear_bit();
+ clear_bit(XPRT_LOCKED, &xprt->state);
+ smp_mb__after_clear_bit();
+ } else
+ schedule_work(&xprt->task_cleanup);
+}
/*
- * 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)) {
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;
}
return 1;
}
- smp_mb__before_clear_bit();
- clear_bit(XPRT_LOCKED, &xprt->state);
- smp_mb__after_clear_bit();
+ xprt_clear_locked(xprt);
out_sleep:
dprintk("RPC: %4d failed to lock transport %p\n", task->tk_pid, xprt);
task->tk_timeout = 0;
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)
+{
+ struct rpc_task *task;
+ struct rpc_rqst *req;
-static void
-__xprt_lock_write_next(struct rpc_xprt *xprt)
+ if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
+ return;
+
+ task = rpc_wake_up_next(&xprt->resend);
+ if (!task) {
+ task = rpc_wake_up_next(&xprt->sending);
+ if (!task)
+ goto out_unlock;
+ }
+
+ req = task->tk_rqstp;
+ xprt->snd_task = task;
+ if (req) {
+ req->rq_bytes_sent = 0;
+ req->rq_ntrans++;
+ }
+ return;
+
+out_unlock:
+ xprt_clear_locked(xprt);
+}
+
+static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
{
struct rpc_task *task;
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
return;
- if (!xprt->nocong && RPCXPRT_CONGESTED(xprt))
+ if (RPCXPRT_CONGESTED(xprt))
goto out_unlock;
task = rpc_wake_up_next(&xprt->resend);
if (!task) {
if (!task)
goto out_unlock;
}
- if (xprt->nocong || __xprt_get_cong(xprt, task)) {
+ if (__xprt_get_cong(xprt, task)) {
struct rpc_rqst *req = task->tk_rqstp;
xprt->snd_task = task;
if (req) {
return;
}
out_unlock:
- smp_mb__before_clear_bit();
- clear_bit(XPRT_LOCKED, &xprt->state);
- smp_mb__after_clear_bit();
+ xprt_clear_locked(xprt);
}
-/*
- * Releases the transport for use by other requests.
+/**
+ * xprt_release_xprt - allow other requests to use a transport
+ * @xprt: transport with other tasks potentially waiting
+ * @task: task that is releasing access to the transport
+ *
+ * Note that "task" can be NULL. No congestion control is provided.
*/
-static void
-__xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
+void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
{
if (xprt->snd_task == task) {
- xprt->snd_task = NULL;
- smp_mb__before_clear_bit();
- clear_bit(XPRT_LOCKED, &xprt->state);
- smp_mb__after_clear_bit();
+ xprt_clear_locked(xprt);
__xprt_lock_write_next(xprt);
}
}
-static inline void
-xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
+/**
+ * xprt_release_xprt_cong - allow other requests to use a transport
+ * @xprt: transport with other tasks potentially waiting
+ * @task: task that is releasing access to the transport
+ *
+ * Note that "task" can be NULL. Another task is awoken to use the
+ * transport if the transport's congestion window allows it.
+ */
+void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+ if (xprt->snd_task == task) {
+ xprt_clear_locked(xprt);
+ __xprt_lock_write_next_cong(xprt);
+ }
+}
+
+static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
{
spin_lock_bh(&xprt->transport_lock);
- __xprt_release_write(xprt, task);
+ xprt->ops->release_xprt(xprt, task);
spin_unlock_bh(&xprt->transport_lock);
}
return;
req->rq_cong = 0;
xprt->cong -= RPC_CWNDSCALE;
- __xprt_lock_write_next(xprt);
+ __xprt_lock_write_next_cong(xprt);
}
-/*
- * Adjust RPC congestion window
+/**
+ * xprt_release_rqst_cong - housekeeping when request is complete
+ * @task: RPC request that recently completed
+ *
+ * Useful for transports that require congestion control.
+ */
+void xprt_release_rqst_cong(struct rpc_task *task)
+{
+ __xprt_put_cong(task->tk_xprt, task->tk_rqstp);
+}
+
+/**
+ * xprt_adjust_cwnd - adjust transport congestion window
+ * @task: recently completed RPC request used to adjust window
+ * @result: result code of completed RPC request
+ *
* We use a time-smoothed congestion estimator to avoid heavy oscillation.
*/
-static void
-xprt_adjust_cwnd(struct rpc_xprt *xprt, int result)
+void xprt_adjust_cwnd(struct rpc_task *task, int result)
{
- unsigned long cwnd;
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = task->tk_xprt;
+ unsigned long cwnd = xprt->cwnd;
- cwnd = xprt->cwnd;
if (result >= 0 && cwnd <= xprt->cong) {
/* The (cwnd >> 1) term makes sure
* the result gets rounded properly. */
cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
if (cwnd > RPC_MAXCWND(xprt))
cwnd = RPC_MAXCWND(xprt);
- __xprt_lock_write_next(xprt);
+ __xprt_lock_write_next_cong(xprt);
} else if (result == -ETIMEDOUT) {
cwnd >>= 1;
if (cwnd < RPC_CWNDSCALE)
dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
xprt->cong, xprt->cwnd, cwnd);
xprt->cwnd = cwnd;
+ __xprt_put_cong(xprt, req);
}
/**
dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid,
xprt, (xprt_connected(xprt) ? "is" : "is not"));
- if (xprt->shutdown) {
- task->tk_status = -EIO;
- return;
- }
if (!xprt->addr.sin_port) {
task->tk_status = -EIO;
return;
if (task->tk_rqstp)
task->tk_rqstp->rq_bytes_sent = 0;
- task->tk_timeout = RPC_CONNECT_TIMEOUT;
+ task->tk_timeout = xprt->connect_timeout;
rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL);
xprt->ops->connect(task);
}
return req;
}
+/**
+ * xprt_update_rtt - update an RPC client's RTT state after receiving a reply
+ * @task: RPC request that recently completed
+ *
+ */
+void xprt_update_rtt(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_rtt *rtt = task->tk_client->cl_rtt;
+ unsigned timer = task->tk_msg.rpc_proc->p_timer;
+
+ if (timer) {
+ if (req->rq_ntrans == 1)
+ rpc_update_rtt(rtt, timer,
+ (long)jiffies - req->rq_xtime);
+ rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
+ }
+}
+
/**
* xprt_complete_rqst - called when reply processing is complete
- * @xprt: controlling transport
- * @req: RPC request that just completed
+ * @task: RPC request that recently completed
* @copied: actual number of bytes received from the transport
*
+ * Caller holds transport lock.
*/
-void xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
-{
- struct rpc_task *task = req->rq_task;
- struct rpc_clnt *clnt = task->tk_client;
-
- /* Adjust congestion window */
- if (!xprt->nocong) {
- unsigned timer = task->tk_msg.rpc_proc->p_timer;
- xprt_adjust_cwnd(xprt, copied);
- __xprt_put_cong(xprt, req);
- if (timer) {
- if (req->rq_ntrans == 1)
- rpc_update_rtt(clnt->cl_rtt, timer,
- (long)jiffies - req->rq_xtime);
- rpc_set_timeo(clnt->cl_rtt, timer, req->rq_ntrans - 1);
- }
- }
+void xprt_complete_rqst(struct rpc_task *task, int copied)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
-#ifdef RPC_PROFILE
- /* Profile only reads for now */
- if (copied > 1024) {
- static unsigned long nextstat;
- static unsigned long pkt_rtt, pkt_len, pkt_cnt;
-
- pkt_cnt++;
- pkt_len += req->rq_slen + copied;
- pkt_rtt += jiffies - req->rq_xtime;
- if (time_before(nextstat, jiffies)) {
- printk("RPC: %lu %ld cwnd\n", jiffies, xprt->cwnd);
- printk("RPC: %ld %ld %ld %ld stat\n",
- jiffies, pkt_cnt, pkt_len, pkt_rtt);
- pkt_rtt = pkt_len = pkt_cnt = 0;
- nextstat = jiffies + 5 * HZ;
- }
- }
-#endif
+ dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
+ task->tk_pid, ntohl(req->rq_xid), copied);
- dprintk("RPC: %4d has input (%d bytes)\n", task->tk_pid, copied);
list_del_init(&req->rq_list);
req->rq_received = req->rq_private_buf.len = copied;
-
- /* ... and wake up the process. */
rpc_wake_up_task(task);
- return;
}
-/*
- * RPC receive timeout handler.
- */
-static void
-xprt_timer(struct rpc_task *task)
+static void xprt_timer(struct rpc_task *task)
{
- struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
- spin_lock(&xprt->transport_lock);
- if (req->rq_received)
- goto out;
-
- xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT);
- __xprt_put_cong(xprt, req);
-
- dprintk("RPC: %4d xprt_timer (%s request)\n",
- task->tk_pid, req ? "pending" : "backlogged");
+ dprintk("RPC: %4d xprt_timer\n", task->tk_pid);
- task->tk_status = -ETIMEDOUT;
-out:
+ spin_lock(&xprt->transport_lock);
+ if (!req->rq_received) {
+ if (xprt->ops->timer)
+ xprt->ops->timer(task);
+ task->tk_status = -ETIMEDOUT;
+ }
task->tk_timeout = 0;
rpc_wake_up_task(task);
spin_unlock(&xprt->transport_lock);
dprintk("RPC: %4d xprt_prepare_transmit\n", task->tk_pid);
- if (xprt->shutdown)
- return -EIO;
-
spin_lock_bh(&xprt->transport_lock);
if (req->rq_received && !req->rq_bytes_sent) {
err = req->rq_received;
goto out_unlock;
}
- if (!__xprt_lock_write(xprt, task)) {
+ if (!xprt->ops->reserve_xprt(task)) {
err = -EAGAIN;
goto out_unlock;
}
return err;
}
+void
+xprt_abort_transmit(struct rpc_task *task)
+{
+ struct rpc_xprt *xprt = task->tk_xprt;
+
+ xprt_release_write(xprt, task);
+}
+
/**
* xprt_transmit - send an RPC request on a transport
* @task: controlling RPC task
task->tk_status = -ENOTCONN;
else if (!req->rq_received)
rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer);
- __xprt_release_write(xprt, task);
+ xprt->ops->release_xprt(xprt, task);
spin_unlock_bh(&xprt->transport_lock);
return;
}
switch (status) {
case -ECONNREFUSED:
- task->tk_timeout = RPC_REESTABLISH_TIMEOUT;
rpc_sleep_on(&xprt->sending, task, NULL, NULL);
case -EAGAIN:
case -ENOTCONN:
struct rpc_xprt *xprt = task->tk_xprt;
task->tk_status = -EIO;
- if (!xprt->shutdown) {
- spin_lock(&xprt->reserve_lock);
- do_xprt_reserve(task);
- spin_unlock(&xprt->reserve_lock);
- }
+ spin_lock(&xprt->reserve_lock);
+ do_xprt_reserve(task);
+ spin_unlock(&xprt->reserve_lock);
}
static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt)
req->rq_timeout = xprt->timeout.to_initval;
req->rq_task = task;
req->rq_xprt = xprt;
+ req->rq_buffer = NULL;
+ req->rq_bufsize = 0;
req->rq_xid = xprt_alloc_xid(xprt);
+ req->rq_release_snd_buf = NULL;
dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid,
req, ntohl(req->rq_xid));
}
if (!(req = task->tk_rqstp))
return;
spin_lock_bh(&xprt->transport_lock);
- __xprt_release_write(xprt, task);
- __xprt_put_cong(xprt, req);
+ 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;
- if (list_empty(&xprt->recv) && !xprt->shutdown)
+ if (list_empty(&xprt->recv))
mod_timer(&xprt->timer,
- xprt->last_used + RPC_IDLE_DISCONNECT_TIMEOUT);
+ xprt->last_used + xprt->idle_timeout);
spin_unlock_bh(&xprt->transport_lock);
+ xprt->ops->buf_free(task);
task->tk_rqstp = NULL;
+ if (req->rq_release_snd_buf)
+ req->rq_release_snd_buf(req);
memset(req, 0, sizeof(*req)); /* mark unused */
dprintk("RPC: %4d release request %p\n", task->tk_pid, req);
spin_lock(&xprt->reserve_lock);
list_add(&req->rq_list, &xprt->free);
- xprt_clear_backlog(xprt);
+ rpc_wake_up_next(&xprt->backlog);
spin_unlock(&xprt->reserve_lock);
}
spin_lock_init(&xprt->transport_lock);
spin_lock_init(&xprt->reserve_lock);
- init_waitqueue_head(&xprt->cong_wait);
INIT_LIST_HEAD(&xprt->free);
INIT_LIST_HEAD(&xprt->recv);
xprt->timer.function = xprt_init_autodisconnect;
xprt->timer.data = (unsigned long) xprt;
xprt->last_used = jiffies;
+ xprt->cwnd = RPC_INITCWND;
rpc_init_wait_queue(&xprt->pending, "xprt_pending");
rpc_init_wait_queue(&xprt->sending, "xprt_sending");
return xprt;
}
-static void xprt_shutdown(struct rpc_xprt *xprt)
-{
- xprt->shutdown = 1;
- rpc_wake_up(&xprt->sending);
- rpc_wake_up(&xprt->resend);
- xprt_wake_pending_tasks(xprt, -EIO);
- rpc_wake_up(&xprt->backlog);
- wake_up(&xprt->cong_wait);
- del_timer_sync(&xprt->timer);
-}
-
-static int xprt_clear_backlog(struct rpc_xprt *xprt) {
- rpc_wake_up_next(&xprt->backlog);
- wake_up(&xprt->cong_wait);
- return 1;
-}
-
/**
* xprt_destroy - destroy an RPC transport, killing off all requests.
* @xprt: transport to destroy
int xprt_destroy(struct rpc_xprt *xprt)
{
dprintk("RPC: destroying transport %p\n", xprt);
- xprt_shutdown(xprt);
+ xprt->shutdown = 1;
+ del_timer_sync(&xprt->timer);
xprt->ops->destroy(xprt);
kfree(xprt);
projects / linux-2.6-omap-h63xx.git / blobdiff