| /* |
| * linux/net/sunrpc/xprt.c |
| * |
| * This is a generic RPC call interface supporting congestion avoidance, |
| * and asynchronous calls. |
| * |
| * The interface works like this: |
| * |
| * - When a process places a call, it allocates a request slot if |
| * one is available. Otherwise, it sleeps on the backlog queue |
| * (xprt_reserve). |
| * - Next, the caller puts together the RPC message, stuffs it into |
| * the request struct, and calls xprt_transmit(). |
| * - xprt_transmit sends the message and installs the caller on the |
| * transport's wait list. At the same time, if a reply is expected, |
| * it installs a timer that is run after the packet's timeout has |
| * expired. |
| * - When a packet arrives, the data_ready handler walks the list of |
| * pending requests for that transport. If a matching XID is found, the |
| * caller is woken up, and the timer removed. |
| * - When no reply arrives within the timeout interval, the timer is |
| * fired by the kernel and runs xprt_timer(). It either adjusts the |
| * timeout values (minor timeout) or wakes up the caller with a status |
| * of -ETIMEDOUT. |
| * - When the caller receives a notification from RPC that a reply arrived, |
| * it should release the RPC slot, and process the reply. |
| * If the call timed out, it may choose to retry the operation by |
| * adjusting the initial timeout value, and simply calling rpc_call |
| * again. |
| * |
| * Support for async RPC is done through a set of RPC-specific scheduling |
| * primitives that `transparently' work for processes as well as async |
| * tasks that rely on callbacks. |
| * |
| * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> |
| * |
| * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> |
| */ |
| |
| #include <linux/module.h> |
| |
| #include <linux/types.h> |
| #include <linux/interrupt.h> |
| #include <linux/workqueue.h> |
| #include <linux/net.h> |
| #include <linux/ktime.h> |
| |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/sunrpc/metrics.h> |
| #include <linux/sunrpc/bc_xprt.h> |
| #include <linux/rcupdate.h> |
| |
| #include <trace/events/sunrpc.h> |
| |
| #include "sunrpc.h" |
| |
| /* |
| * Local variables |
| */ |
| |
| #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
| # define RPCDBG_FACILITY RPCDBG_XPRT |
| #endif |
| |
| /* |
| * Local functions |
| */ |
| static void xprt_init(struct rpc_xprt *xprt, struct net *net); |
| static void xprt_request_init(struct rpc_task *, struct rpc_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); |
| static LIST_HEAD(xprt_list); |
| |
| /** |
| * xprt_register_transport - register a transport implementation |
| * @transport: transport to register |
| * |
| * If a transport implementation is loaded as a kernel module, it can |
| * call this interface to make itself known to the RPC client. |
| * |
| * Returns: |
| * 0: transport successfully registered |
| * -EEXIST: transport already registered |
| * -EINVAL: transport module being unloaded |
| */ |
| int xprt_register_transport(struct xprt_class *transport) |
| { |
| struct xprt_class *t; |
| int result; |
| |
| result = -EEXIST; |
| spin_lock(&xprt_list_lock); |
| list_for_each_entry(t, &xprt_list, list) { |
| /* don't register the same transport class twice */ |
| if (t->ident == transport->ident) |
| goto out; |
| } |
| |
| list_add_tail(&transport->list, &xprt_list); |
| printk(KERN_INFO "RPC: Registered %s transport module.\n", |
| transport->name); |
| result = 0; |
| |
| out: |
| spin_unlock(&xprt_list_lock); |
| return result; |
| } |
| EXPORT_SYMBOL_GPL(xprt_register_transport); |
| |
| /** |
| * xprt_unregister_transport - unregister a transport implementation |
| * @transport: transport to unregister |
| * |
| * Returns: |
| * 0: transport successfully unregistered |
| * -ENOENT: transport never registered |
| */ |
| int xprt_unregister_transport(struct xprt_class *transport) |
| { |
| struct xprt_class *t; |
| int result; |
| |
| result = 0; |
| spin_lock(&xprt_list_lock); |
| list_for_each_entry(t, &xprt_list, list) { |
| if (t == transport) { |
| printk(KERN_INFO |
| "RPC: Unregistered %s transport module.\n", |
| transport->name); |
| list_del_init(&transport->list); |
| goto out; |
| } |
| } |
| result = -ENOENT; |
| |
| out: |
| spin_unlock(&xprt_list_lock); |
| return result; |
| } |
| EXPORT_SYMBOL_GPL(xprt_unregister_transport); |
| |
| /** |
| * xprt_load_transport - load a transport implementation |
| * @transport_name: transport to load |
| * |
| * Returns: |
| * 0: transport successfully loaded |
| * -ENOENT: transport module not available |
| */ |
| int xprt_load_transport(const char *transport_name) |
| { |
| struct xprt_class *t; |
| int result; |
| |
| result = 0; |
| spin_lock(&xprt_list_lock); |
| list_for_each_entry(t, &xprt_list, list) { |
| if (strcmp(t->name, transport_name) == 0) { |
| spin_unlock(&xprt_list_lock); |
| goto out; |
| } |
| } |
| spin_unlock(&xprt_list_lock); |
| result = request_module("xprt%s", transport_name); |
| out: |
| return result; |
| } |
| EXPORT_SYMBOL_GPL(xprt_load_transport); |
| |
| /** |
| * xprt_reserve_xprt - serialize write access to transports |
| * @task: task that is requesting access to the transport |
| * @xprt: pointer to the target 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_xprt *xprt, struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| int priority; |
| |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
| if (task == xprt->snd_task) |
| return 1; |
| goto out_sleep; |
| } |
| xprt->snd_task = task; |
| if (req != NULL) |
| req->rq_ntrans++; |
| |
| return 1; |
| |
| out_sleep: |
| dprintk("RPC: %5u failed to lock transport %p\n", |
| task->tk_pid, xprt); |
| task->tk_timeout = 0; |
| task->tk_status = -EAGAIN; |
| if (req == NULL) |
| priority = RPC_PRIORITY_LOW; |
| else if (!req->rq_ntrans) |
| priority = RPC_PRIORITY_NORMAL; |
| else |
| priority = RPC_PRIORITY_HIGH; |
| rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
| |
| static void xprt_clear_locked(struct rpc_xprt *xprt) |
| { |
| xprt->snd_task = NULL; |
| if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { |
| smp_mb__before_atomic(); |
| clear_bit(XPRT_LOCKED, &xprt->state); |
| smp_mb__after_atomic(); |
| } else |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| } |
| |
| /* |
| * 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. |
| */ |
| int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| int priority; |
| |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
| if (task == xprt->snd_task) |
| return 1; |
| goto out_sleep; |
| } |
| if (req == NULL) { |
| xprt->snd_task = task; |
| return 1; |
| } |
| if (__xprt_get_cong(xprt, task)) { |
| xprt->snd_task = task; |
| req->rq_ntrans++; |
| 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; |
| if (req == NULL) |
| priority = RPC_PRIORITY_LOW; |
| else if (!req->rq_ntrans) |
| priority = RPC_PRIORITY_NORMAL; |
| else |
| priority = RPC_PRIORITY_HIGH; |
| rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
| |
| static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| int retval; |
| |
| spin_lock_bh(&xprt->transport_lock); |
| retval = xprt->ops->reserve_xprt(xprt, task); |
| spin_unlock_bh(&xprt->transport_lock); |
| return retval; |
| } |
| |
| static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
| { |
| struct rpc_xprt *xprt = data; |
| struct rpc_rqst *req; |
| |
| req = task->tk_rqstp; |
| xprt->snd_task = task; |
| if (req) |
| req->rq_ntrans++; |
| return true; |
| } |
| |
| static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
| { |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
| return; |
| |
| if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
| __xprt_lock_write_func, xprt)) |
| return; |
| 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)) |
| goto out_unlock; |
| if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
| __xprt_lock_write_cong_func, xprt)) |
| return; |
| out_unlock: |
| xprt_clear_locked(xprt); |
| } |
| |
| static void xprt_task_clear_bytes_sent(struct rpc_task *task) |
| { |
| if (task != NULL) { |
| struct rpc_rqst *req = task->tk_rqstp; |
| if (req != NULL) |
| req->rq_bytes_sent = 0; |
| } |
| } |
| |
| /** |
| * 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. |
| */ |
| void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| if (xprt->snd_task == task) { |
| xprt_task_clear_bytes_sent(task); |
| xprt_clear_locked(xprt); |
| __xprt_lock_write_next(xprt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(xprt_release_xprt); |
| |
| /** |
| * 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_task_clear_bytes_sent(task); |
| xprt_clear_locked(xprt); |
| __xprt_lock_write_next_cong(xprt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
| |
| static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| spin_lock_bh(&xprt->transport_lock); |
| xprt->ops->release_xprt(xprt, task); |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| |
| /* |
| * Van Jacobson congestion avoidance. Check if the congestion window |
| * overflowed. Put the task to sleep if this is the case. |
| */ |
| static int |
| __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| 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)) |
| return 0; |
| req->rq_cong = 1; |
| xprt->cong += RPC_CWNDSCALE; |
| return 1; |
| } |
| |
| /* |
| * Adjust the congestion window, and wake up the next task |
| * that has been sleeping due to congestion |
| */ |
| static void |
| __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| if (!req->rq_cong) |
| return; |
| req->rq_cong = 0; |
| xprt->cong -= RPC_CWNDSCALE; |
| __xprt_lock_write_next_cong(xprt); |
| } |
| |
| /** |
| * 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) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| __xprt_put_cong(req->rq_xprt, req); |
| } |
| EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
| |
| /** |
| * xprt_adjust_cwnd - adjust transport congestion window |
| * @xprt: pointer to xprt |
| * @task: recently completed RPC request used to adjust window |
| * @result: result code of completed RPC request |
| * |
| * 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. |
| */ |
| void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| unsigned long 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_cong(xprt); |
| } else if (result == -ETIMEDOUT) { |
| cwnd >>= 1; |
| if (cwnd < RPC_CWNDSCALE) |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
| |
| /** |
| * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue |
| * @xprt: transport with waiting tasks |
| * @status: result code to plant in each task before waking it |
| * |
| */ |
| void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) |
| { |
| if (status < 0) |
| rpc_wake_up_status(&xprt->pending, status); |
| else |
| rpc_wake_up(&xprt->pending); |
| } |
| EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
| |
| /** |
| * xprt_wait_for_buffer_space - wait for transport output buffer to clear |
| * @task: task to be put to sleep |
| * @action: function pointer to be executed after wait |
| * |
| * Note that we only set the timer for the case of RPC_IS_SOFT(), since |
| * we don't in general want to force a socket disconnection due to |
| * an incomplete RPC call transmission. |
| */ |
| void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0; |
| rpc_sleep_on(&xprt->pending, task, action); |
| } |
| EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
| |
| /** |
| * xprt_write_space - wake the task waiting for transport output buffer space |
| * @xprt: transport with waiting tasks |
| * |
| * Can be called in a soft IRQ context, so xprt_write_space never sleeps. |
| */ |
| void xprt_write_space(struct rpc_xprt *xprt) |
| { |
| spin_lock_bh(&xprt->transport_lock); |
| if (xprt->snd_task) { |
| dprintk("RPC: write space: waking waiting task on " |
| "xprt %p\n", xprt); |
| rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); |
| } |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_write_space); |
| |
| /** |
| * xprt_set_retrans_timeout_def - set a request's retransmit timeout |
| * @task: task whose timeout is to be set |
| * |
| * Set a request's retransmit timeout based on the transport's |
| * default timeout parameters. Used by transports that don't adjust |
| * the retransmit timeout based on round-trip time estimation. |
| */ |
| void xprt_set_retrans_timeout_def(struct rpc_task *task) |
| { |
| task->tk_timeout = task->tk_rqstp->rq_timeout; |
| } |
| EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); |
| |
| /** |
| * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout |
| * @task: task whose timeout is to be set |
| * |
| * Set a request's retransmit timeout using the RTT estimator. |
| */ |
| void xprt_set_retrans_timeout_rtt(struct rpc_task *task) |
| { |
| int timer = task->tk_msg.rpc_proc->p_timer; |
| struct rpc_clnt *clnt = task->tk_client; |
| struct rpc_rtt *rtt = clnt->cl_rtt; |
| struct rpc_rqst *req = task->tk_rqstp; |
| unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
| |
| task->tk_timeout = rpc_calc_rto(rtt, timer); |
| task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; |
| if (task->tk_timeout > max_timeout || task->tk_timeout == 0) |
| task->tk_timeout = max_timeout; |
| } |
| EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); |
| |
| static void xprt_reset_majortimeo(struct rpc_rqst *req) |
| { |
| const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
| |
| req->rq_majortimeo = req->rq_timeout; |
| if (to->to_exponential) |
| req->rq_majortimeo <<= to->to_retries; |
| else |
| req->rq_majortimeo += to->to_increment * to->to_retries; |
| if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) |
| req->rq_majortimeo = to->to_maxval; |
| req->rq_majortimeo += jiffies; |
| } |
| |
| /** |
| * xprt_adjust_timeout - adjust timeout values for next retransmit |
| * @req: RPC request containing parameters to use for the adjustment |
| * |
| */ |
| int xprt_adjust_timeout(struct rpc_rqst *req) |
| { |
| struct rpc_xprt *xprt = req->rq_xprt; |
| const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
| int status = 0; |
| |
| if (time_before(jiffies, req->rq_majortimeo)) { |
| if (to->to_exponential) |
| req->rq_timeout <<= 1; |
| else |
| req->rq_timeout += to->to_increment; |
| if (to->to_maxval && req->rq_timeout >= to->to_maxval) |
| req->rq_timeout = to->to_maxval; |
| req->rq_retries++; |
| } else { |
| req->rq_timeout = to->to_initval; |
| req->rq_retries = 0; |
| xprt_reset_majortimeo(req); |
| /* Reset the RTT counters == "slow start" */ |
| spin_lock_bh(&xprt->transport_lock); |
| rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
| spin_unlock_bh(&xprt->transport_lock); |
| status = -ETIMEDOUT; |
| } |
| |
| if (req->rq_timeout == 0) { |
| printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); |
| req->rq_timeout = 5 * HZ; |
| } |
| return status; |
| } |
| |
| static void xprt_autoclose(struct work_struct *work) |
| { |
| struct rpc_xprt *xprt = |
| container_of(work, struct rpc_xprt, task_cleanup); |
| |
| clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
| xprt->ops->close(xprt); |
| xprt_release_write(xprt, NULL); |
| wake_up_bit(&xprt->state, XPRT_LOCKED); |
| } |
| |
| /** |
| * xprt_disconnect_done - mark a transport as disconnected |
| * @xprt: transport to flag for disconnect |
| * |
| */ |
| void xprt_disconnect_done(struct rpc_xprt *xprt) |
| { |
| dprintk("RPC: disconnected transport %p\n", xprt); |
| spin_lock_bh(&xprt->transport_lock); |
| xprt_clear_connected(xprt); |
| xprt_wake_pending_tasks(xprt, -EAGAIN); |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
| |
| /** |
| * xprt_force_disconnect - force a transport to disconnect |
| * @xprt: transport to disconnect |
| * |
| */ |
| void xprt_force_disconnect(struct rpc_xprt *xprt) |
| { |
| /* Don't race with the test_bit() in xprt_clear_locked() */ |
| spin_lock_bh(&xprt->transport_lock); |
| set_bit(XPRT_CLOSE_WAIT, &xprt->state); |
| /* Try to schedule an autoclose RPC call */ |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| xprt_wake_pending_tasks(xprt, -EAGAIN); |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| |
| /** |
| * xprt_conditional_disconnect - force a transport to disconnect |
| * @xprt: transport to disconnect |
| * @cookie: 'connection cookie' |
| * |
| * This attempts to break the connection if and only if 'cookie' matches |
| * the current transport 'connection cookie'. It ensures that we don't |
| * try to break the connection more than once when we need to retransmit |
| * a batch of RPC requests. |
| * |
| */ |
| void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) |
| { |
| /* Don't race with the test_bit() in xprt_clear_locked() */ |
| spin_lock_bh(&xprt->transport_lock); |
| if (cookie != xprt->connect_cookie) |
| goto out; |
| if (test_bit(XPRT_CLOSING, &xprt->state)) |
| goto out; |
| set_bit(XPRT_CLOSE_WAIT, &xprt->state); |
| /* Try to schedule an autoclose RPC call */ |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| xprt_wake_pending_tasks(xprt, -EAGAIN); |
| out: |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| |
| static bool |
| xprt_has_timer(const struct rpc_xprt *xprt) |
| { |
| return xprt->idle_timeout != 0; |
| } |
| |
| static void |
| xprt_schedule_autodisconnect(struct rpc_xprt *xprt) |
| __must_hold(&xprt->transport_lock) |
| { |
| if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) |
| mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout); |
| } |
| |
| static void |
| xprt_init_autodisconnect(unsigned long data) |
| { |
| struct rpc_xprt *xprt = (struct rpc_xprt *)data; |
| |
| spin_lock(&xprt->transport_lock); |
| if (!list_empty(&xprt->recv)) |
| goto out_abort; |
| /* Reset xprt->last_used to avoid connect/autodisconnect cycling */ |
| xprt->last_used = jiffies; |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
| goto out_abort; |
| spin_unlock(&xprt->transport_lock); |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| return; |
| out_abort: |
| spin_unlock(&xprt->transport_lock); |
| } |
| |
| bool xprt_lock_connect(struct rpc_xprt *xprt, |
| struct rpc_task *task, |
| void *cookie) |
| { |
| bool ret = false; |
| |
| spin_lock_bh(&xprt->transport_lock); |
| if (!test_bit(XPRT_LOCKED, &xprt->state)) |
| goto out; |
| if (xprt->snd_task != task) |
| goto out; |
| xprt_task_clear_bytes_sent(task); |
| xprt->snd_task = cookie; |
| ret = true; |
| out: |
| spin_unlock_bh(&xprt->transport_lock); |
| return ret; |
| } |
| |
| void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) |
| { |
| spin_lock_bh(&xprt->transport_lock); |
| if (xprt->snd_task != cookie) |
| goto out; |
| if (!test_bit(XPRT_LOCKED, &xprt->state)) |
| goto out; |
| xprt->snd_task =NULL; |
| xprt->ops->release_xprt(xprt, NULL); |
| xprt_schedule_autodisconnect(xprt); |
| out: |
| spin_unlock_bh(&xprt->transport_lock); |
| wake_up_bit(&xprt->state, XPRT_LOCKED); |
| } |
| |
| /** |
| * xprt_connect - schedule a transport connect operation |
| * @task: RPC task that is requesting the connect |
| * |
| */ |
| void xprt_connect(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
| |
| dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, |
| xprt, (xprt_connected(xprt) ? "is" : "is not")); |
| |
| if (!xprt_bound(xprt)) { |
| task->tk_status = -EAGAIN; |
| return; |
| } |
| if (!xprt_lock_write(xprt, task)) |
| return; |
| |
| if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) |
| xprt->ops->close(xprt); |
| |
| if (!xprt_connected(xprt)) { |
| task->tk_rqstp->rq_bytes_sent = 0; |
| task->tk_timeout = task->tk_rqstp->rq_timeout; |
| task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie; |
| rpc_sleep_on(&xprt->pending, task, xprt_connect_status); |
| |
| if (test_bit(XPRT_CLOSING, &xprt->state)) |
| return; |
| if (xprt_test_and_set_connecting(xprt)) |
| return; |
| xprt->stat.connect_start = jiffies; |
| xprt->ops->connect(xprt, task); |
| } |
| xprt_release_write(xprt, task); |
| } |
| |
| static void xprt_connect_status(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
| |
| if (task->tk_status == 0) { |
| xprt->stat.connect_count++; |
| xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; |
| dprintk("RPC: %5u xprt_connect_status: connection established\n", |
| task->tk_pid); |
| return; |
| } |
| |
| switch (task->tk_status) { |
| case -ECONNREFUSED: |
| case -ECONNRESET: |
| case -ECONNABORTED: |
| case -ENETUNREACH: |
| case -EHOSTUNREACH: |
| case -EPIPE: |
| case -EAGAIN: |
| dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); |
| break; |
| case -ETIMEDOUT: |
| dprintk("RPC: %5u xprt_connect_status: connect attempt timed " |
| "out\n", task->tk_pid); |
| break; |
| default: |
| dprintk("RPC: %5u xprt_connect_status: error %d connecting to " |
| "server %s\n", task->tk_pid, -task->tk_status, |
| xprt->servername); |
| task->tk_status = -EIO; |
| } |
| } |
| |
| /** |
| * xprt_lookup_rqst - find an RPC request corresponding to an XID |
| * @xprt: transport on which the original request was transmitted |
| * @xid: RPC XID of incoming reply |
| * |
| */ |
| struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
| { |
| struct rpc_rqst *entry; |
| |
| list_for_each_entry(entry, &xprt->recv, rq_list) |
| if (entry->rq_xid == xid) { |
| trace_xprt_lookup_rqst(xprt, xid, 0); |
| return entry; |
| } |
| |
| dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", |
| ntohl(xid)); |
| trace_xprt_lookup_rqst(xprt, xid, -ENOENT); |
| xprt->stat.bad_xids++; |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
| |
| static 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 int timer = task->tk_msg.rpc_proc->p_timer; |
| long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); |
| |
| if (timer) { |
| if (req->rq_ntrans == 1) |
| rpc_update_rtt(rtt, timer, m); |
| rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); |
| } |
| } |
| |
| /** |
| * xprt_complete_rqst - called when reply processing is complete |
| * @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_task *task, int copied) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", |
| task->tk_pid, ntohl(req->rq_xid), copied); |
| trace_xprt_complete_rqst(xprt, req->rq_xid, copied); |
| |
| xprt->stat.recvs++; |
| req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); |
| if (xprt->ops->timer != NULL) |
| xprt_update_rtt(task); |
| |
| list_del_init(&req->rq_list); |
| req->rq_private_buf.len = copied; |
| /* Ensure all writes are done before we update */ |
| /* req->rq_reply_bytes_recvd */ |
| smp_wmb(); |
| req->rq_reply_bytes_recvd = copied; |
| rpc_wake_up_queued_task(&xprt->pending, task); |
| } |
| EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
| |
| static void xprt_timer(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (task->tk_status != -ETIMEDOUT) |
| return; |
| dprintk("RPC: %5u xprt_timer\n", task->tk_pid); |
| |
| if (!req->rq_reply_bytes_recvd) { |
| if (xprt->ops->timer) |
| xprt->ops->timer(xprt, task); |
| } else |
| task->tk_status = 0; |
| } |
| |
| /** |
| * xprt_prepare_transmit - reserve the transport before sending a request |
| * @task: RPC task about to send a request |
| * |
| */ |
| bool xprt_prepare_transmit(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| bool ret = false; |
| |
| dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); |
| |
| spin_lock_bh(&xprt->transport_lock); |
| if (!req->rq_bytes_sent) { |
| if (req->rq_reply_bytes_recvd) { |
| task->tk_status = req->rq_reply_bytes_recvd; |
| goto out_unlock; |
| } |
| if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) |
| && xprt_connected(xprt) |
| && req->rq_connect_cookie == xprt->connect_cookie) { |
| xprt->ops->set_retrans_timeout(task); |
| rpc_sleep_on(&xprt->pending, task, xprt_timer); |
| goto out_unlock; |
| } |
| } |
| if (!xprt->ops->reserve_xprt(xprt, task)) { |
| task->tk_status = -EAGAIN; |
| goto out_unlock; |
| } |
| ret = true; |
| out_unlock: |
| spin_unlock_bh(&xprt->transport_lock); |
| return ret; |
| } |
| |
| void xprt_end_transmit(struct rpc_task *task) |
| { |
| xprt_release_write(task->tk_rqstp->rq_xprt, task); |
| } |
| |
| /** |
| * xprt_transmit - send an RPC request on a transport |
| * @task: controlling RPC task |
| * |
| * We have to copy the iovec because sendmsg fiddles with its contents. |
| */ |
| void xprt_transmit(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| int status, numreqs; |
| |
| dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); |
| |
| if (!req->rq_reply_bytes_recvd) { |
| if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { |
| /* |
| * Add to the list only if we're expecting a reply |
| */ |
| spin_lock_bh(&xprt->transport_lock); |
| /* Update the softirq receive buffer */ |
| memcpy(&req->rq_private_buf, &req->rq_rcv_buf, |
| sizeof(req->rq_private_buf)); |
| /* Add request to the receive list */ |
| list_add_tail(&req->rq_list, &xprt->recv); |
| spin_unlock_bh(&xprt->transport_lock); |
| xprt_reset_majortimeo(req); |
| /* Turn off autodisconnect */ |
| del_singleshot_timer_sync(&xprt->timer); |
| } |
| } else if (!req->rq_bytes_sent) |
| return; |
| |
| req->rq_xtime = ktime_get(); |
| status = xprt->ops->send_request(task); |
| trace_xprt_transmit(xprt, req->rq_xid, status); |
| if (status != 0) { |
| task->tk_status = status; |
| return; |
| } |
| xprt_inject_disconnect(xprt); |
| |
| dprintk("RPC: %5u xmit complete\n", task->tk_pid); |
| task->tk_flags |= RPC_TASK_SENT; |
| spin_lock_bh(&xprt->transport_lock); |
| |
| xprt->ops->set_retrans_timeout(task); |
| |
| numreqs = atomic_read(&xprt->num_reqs); |
| if (numreqs > xprt->stat.max_slots) |
| xprt->stat.max_slots = numreqs; |
| xprt->stat.sends++; |
| xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; |
| xprt->stat.bklog_u += xprt->backlog.qlen; |
| xprt->stat.sending_u += xprt->sending.qlen; |
| xprt->stat.pending_u += xprt->pending.qlen; |
| |
| /* Don't race with disconnect */ |
| if (!xprt_connected(xprt)) |
| task->tk_status = -ENOTCONN; |
| else { |
| /* |
| * Sleep on the pending queue since |
| * we're expecting a reply. |
| */ |
| if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) |
| rpc_sleep_on(&xprt->pending, task, xprt_timer); |
| req->rq_connect_cookie = xprt->connect_cookie; |
| } |
| spin_unlock_bh(&xprt->transport_lock); |
| } |
| |
| static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| set_bit(XPRT_CONGESTED, &xprt->state); |
| rpc_sleep_on(&xprt->backlog, task, NULL); |
| } |
| |
| static void xprt_wake_up_backlog(struct rpc_xprt *xprt) |
| { |
| if (rpc_wake_up_next(&xprt->backlog) == NULL) |
| clear_bit(XPRT_CONGESTED, &xprt->state); |
| } |
| |
| static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| bool ret = false; |
| |
| if (!test_bit(XPRT_CONGESTED, &xprt->state)) |
| goto out; |
| spin_lock(&xprt->reserve_lock); |
| if (test_bit(XPRT_CONGESTED, &xprt->state)) { |
| rpc_sleep_on(&xprt->backlog, task, NULL); |
| ret = true; |
| } |
| spin_unlock(&xprt->reserve_lock); |
| out: |
| return ret; |
| } |
| |
| static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) |
| { |
| struct rpc_rqst *req = ERR_PTR(-EAGAIN); |
| |
| if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) |
| goto out; |
| req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); |
| if (req != NULL) |
| goto out; |
| atomic_dec(&xprt->num_reqs); |
| req = ERR_PTR(-ENOMEM); |
| out: |
| return req; |
| } |
| |
| static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { |
| kfree(req); |
| return true; |
| } |
| return false; |
| } |
| |
| void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| struct rpc_rqst *req; |
| |
| spin_lock(&xprt->reserve_lock); |
| if (!list_empty(&xprt->free)) { |
| req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
| list_del(&req->rq_list); |
| goto out_init_req; |
| } |
| req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN); |
| if (!IS_ERR(req)) |
| goto out_init_req; |
| switch (PTR_ERR(req)) { |
| case -ENOMEM: |
| dprintk("RPC: dynamic allocation of request slot " |
| "failed! Retrying\n"); |
| task->tk_status = -ENOMEM; |
| break; |
| case -EAGAIN: |
| xprt_add_backlog(xprt, task); |
| dprintk("RPC: waiting for request slot\n"); |
| default: |
| task->tk_status = -EAGAIN; |
| } |
| spin_unlock(&xprt->reserve_lock); |
| return; |
| out_init_req: |
| task->tk_status = 0; |
| task->tk_rqstp = req; |
| xprt_request_init(task, xprt); |
| spin_unlock(&xprt->reserve_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_alloc_slot); |
| |
| void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| /* Note: grabbing the xprt_lock_write() ensures that we throttle |
| * new slot allocation if the transport is congested (i.e. when |
| * reconnecting a stream transport or when out of socket write |
| * buffer space). |
| */ |
| if (xprt_lock_write(xprt, task)) { |
| xprt_alloc_slot(xprt, task); |
| xprt_release_write(xprt, task); |
| } |
| } |
| EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot); |
| |
| static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| spin_lock(&xprt->reserve_lock); |
| if (!xprt_dynamic_free_slot(xprt, req)) { |
| memset(req, 0, sizeof(*req)); /* mark unused */ |
| list_add(&req->rq_list, &xprt->free); |
| } |
| xprt_wake_up_backlog(xprt); |
| spin_unlock(&xprt->reserve_lock); |
| } |
| |
| static void xprt_free_all_slots(struct rpc_xprt *xprt) |
| { |
| struct rpc_rqst *req; |
| while (!list_empty(&xprt->free)) { |
| req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); |
| list_del(&req->rq_list); |
| kfree(req); |
| } |
| } |
| |
| struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
| unsigned int num_prealloc, |
| unsigned int max_alloc) |
| { |
| struct rpc_xprt *xprt; |
| struct rpc_rqst *req; |
| int i; |
| |
| xprt = kzalloc(size, GFP_KERNEL); |
| if (xprt == NULL) |
| goto out; |
| |
| xprt_init(xprt, net); |
| |
| for (i = 0; i < num_prealloc; i++) { |
| req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); |
| if (!req) |
| goto out_free; |
| list_add(&req->rq_list, &xprt->free); |
| } |
| if (max_alloc > num_prealloc) |
| xprt->max_reqs = max_alloc; |
| else |
| xprt->max_reqs = num_prealloc; |
| xprt->min_reqs = num_prealloc; |
| atomic_set(&xprt->num_reqs, num_prealloc); |
| |
| return xprt; |
| |
| out_free: |
| xprt_free(xprt); |
| out: |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(xprt_alloc); |
| |
| void xprt_free(struct rpc_xprt *xprt) |
| { |
| put_net(xprt->xprt_net); |
| xprt_free_all_slots(xprt); |
| kfree_rcu(xprt, rcu); |
| } |
| EXPORT_SYMBOL_GPL(xprt_free); |
| |
| /** |
| * xprt_reserve - allocate an RPC request slot |
| * @task: RPC task requesting a slot allocation |
| * |
| * If the transport is marked as being congested, or if no more |
| * slots are available, place the task on the transport's |
| * backlog queue. |
| */ |
| void xprt_reserve(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt = task->tk_xprt; |
| |
| task->tk_status = 0; |
| if (task->tk_rqstp != NULL) |
| return; |
| |
| task->tk_timeout = 0; |
| task->tk_status = -EAGAIN; |
| if (!xprt_throttle_congested(xprt, task)) |
| xprt->ops->alloc_slot(xprt, task); |
| } |
| |
| /** |
| * xprt_retry_reserve - allocate an RPC request slot |
| * @task: RPC task requesting a slot allocation |
| * |
| * If no more slots are available, place the task on the transport's |
| * backlog queue. |
| * Note that the only difference with xprt_reserve is that we now |
| * ignore the value of the XPRT_CONGESTED flag. |
| */ |
| void xprt_retry_reserve(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt = task->tk_xprt; |
| |
| task->tk_status = 0; |
| if (task->tk_rqstp != NULL) |
| return; |
| |
| task->tk_timeout = 0; |
| task->tk_status = -EAGAIN; |
| xprt->ops->alloc_slot(xprt, task); |
| } |
| |
| static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) |
| { |
| return (__force __be32)xprt->xid++; |
| } |
| |
| static inline void xprt_init_xid(struct rpc_xprt *xprt) |
| { |
| xprt->xid = prandom_u32(); |
| } |
| |
| static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| INIT_LIST_HEAD(&req->rq_list); |
| req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
| req->rq_task = task; |
| req->rq_xprt = xprt; |
| req->rq_buffer = NULL; |
| req->rq_xid = xprt_alloc_xid(xprt); |
| req->rq_connect_cookie = xprt->connect_cookie - 1; |
| req->rq_bytes_sent = 0; |
| req->rq_snd_buf.len = 0; |
| req->rq_snd_buf.buflen = 0; |
| req->rq_rcv_buf.len = 0; |
| req->rq_rcv_buf.buflen = 0; |
| req->rq_release_snd_buf = NULL; |
| xprt_reset_majortimeo(req); |
| dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, |
| req, ntohl(req->rq_xid)); |
| } |
| |
| /** |
| * xprt_release - release an RPC request slot |
| * @task: task which is finished with the slot |
| * |
| */ |
| void xprt_release(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt; |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| if (req == NULL) { |
| if (task->tk_client) { |
| xprt = task->tk_xprt; |
| if (xprt->snd_task == task) |
| xprt_release_write(xprt, task); |
| } |
| return; |
| } |
| |
| xprt = req->rq_xprt; |
| if (task->tk_ops->rpc_count_stats != NULL) |
| task->tk_ops->rpc_count_stats(task, task->tk_calldata); |
| else if (task->tk_client) |
| rpc_count_iostats(task, task->tk_client->cl_metrics); |
| spin_lock_bh(&xprt->transport_lock); |
| 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; |
| xprt_schedule_autodisconnect(xprt); |
| spin_unlock_bh(&xprt->transport_lock); |
| if (req->rq_buffer) |
| xprt->ops->buf_free(task); |
| xprt_inject_disconnect(xprt); |
| if (req->rq_cred != NULL) |
| put_rpccred(req->rq_cred); |
| task->tk_rqstp = NULL; |
| if (req->rq_release_snd_buf) |
| req->rq_release_snd_buf(req); |
| |
| dprintk("RPC: %5u release request %p\n", task->tk_pid, req); |
| if (likely(!bc_prealloc(req))) |
| xprt_free_slot(xprt, req); |
| else |
| xprt_free_bc_request(req); |
| } |
| |
| static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
| { |
| kref_init(&xprt->kref); |
| |
| spin_lock_init(&xprt->transport_lock); |
| spin_lock_init(&xprt->reserve_lock); |
| |
| INIT_LIST_HEAD(&xprt->free); |
| INIT_LIST_HEAD(&xprt->recv); |
| #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
| spin_lock_init(&xprt->bc_pa_lock); |
| INIT_LIST_HEAD(&xprt->bc_pa_list); |
| #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
| INIT_LIST_HEAD(&xprt->xprt_switch); |
| |
| xprt->last_used = jiffies; |
| xprt->cwnd = RPC_INITCWND; |
| xprt->bind_index = 0; |
| |
| rpc_init_wait_queue(&xprt->binding, "xprt_binding"); |
| rpc_init_wait_queue(&xprt->pending, "xprt_pending"); |
| rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); |
| rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
| |
| xprt_init_xid(xprt); |
| |
| xprt->xprt_net = get_net(net); |
| } |
| |
| /** |
| * xprt_create_transport - create an RPC transport |
| * @args: rpc transport creation arguments |
| * |
| */ |
| struct rpc_xprt *xprt_create_transport(struct xprt_create *args) |
| { |
| struct rpc_xprt *xprt; |
| struct xprt_class *t; |
| |
| spin_lock(&xprt_list_lock); |
| list_for_each_entry(t, &xprt_list, list) { |
| if (t->ident == args->ident) { |
| spin_unlock(&xprt_list_lock); |
| goto found; |
| } |
| } |
| spin_unlock(&xprt_list_lock); |
| dprintk("RPC: transport (%d) not supported\n", args->ident); |
| return ERR_PTR(-EIO); |
| |
| found: |
| xprt = t->setup(args); |
| if (IS_ERR(xprt)) { |
| dprintk("RPC: xprt_create_transport: failed, %ld\n", |
| -PTR_ERR(xprt)); |
| goto out; |
| } |
| if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT) |
| xprt->idle_timeout = 0; |
| INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
| if (xprt_has_timer(xprt)) |
| setup_timer(&xprt->timer, xprt_init_autodisconnect, |
| (unsigned long)xprt); |
| else |
| init_timer(&xprt->timer); |
| |
| if (strlen(args->servername) > RPC_MAXNETNAMELEN) { |
| xprt_destroy(xprt); |
| return ERR_PTR(-EINVAL); |
| } |
| xprt->servername = kstrdup(args->servername, GFP_KERNEL); |
| if (xprt->servername == NULL) { |
| xprt_destroy(xprt); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| rpc_xprt_debugfs_register(xprt); |
| |
| dprintk("RPC: created transport %p with %u slots\n", xprt, |
| xprt->max_reqs); |
| out: |
| return xprt; |
| } |
| |
| /** |
| * xprt_destroy - destroy an RPC transport, killing off all requests. |
| * @xprt: transport to destroy |
| * |
| */ |
| static void xprt_destroy(struct rpc_xprt *xprt) |
| { |
| dprintk("RPC: destroying transport %p\n", xprt); |
| |
| /* Exclude transport connect/disconnect handlers */ |
| wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); |
| |
| del_timer_sync(&xprt->timer); |
| |
| rpc_xprt_debugfs_unregister(xprt); |
| rpc_destroy_wait_queue(&xprt->binding); |
| rpc_destroy_wait_queue(&xprt->pending); |
| rpc_destroy_wait_queue(&xprt->sending); |
| rpc_destroy_wait_queue(&xprt->backlog); |
| cancel_work_sync(&xprt->task_cleanup); |
| kfree(xprt->servername); |
| /* |
| * Tear down transport state and free the rpc_xprt |
| */ |
| xprt->ops->destroy(xprt); |
| } |
| |
| static void xprt_destroy_kref(struct kref *kref) |
| { |
| xprt_destroy(container_of(kref, struct rpc_xprt, kref)); |
| } |
| |
| /** |
| * xprt_get - return a reference to an RPC transport. |
| * @xprt: pointer to the transport |
| * |
| */ |
| struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) |
| { |
| if (xprt != NULL && kref_get_unless_zero(&xprt->kref)) |
| return xprt; |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(xprt_get); |
| |
| /** |
| * xprt_put - release a reference to an RPC transport. |
| * @xprt: pointer to the transport |
| * |
| */ |
| void xprt_put(struct rpc_xprt *xprt) |
| { |
| if (xprt != NULL) |
| kref_put(&xprt->kref, xprt_destroy_kref); |
| } |
| EXPORT_SYMBOL_GPL(xprt_put); |