| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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 <linux/sched/mm.h> |
| |
| #include <trace/events/sunrpc.h> |
| |
| #include "sunrpc.h" |
| #include "sysfs.h" |
| #include "fail.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 __be32 xprt_alloc_xid(struct rpc_xprt *xprt); |
| static void xprt_destroy(struct rpc_xprt *xprt); |
| static void xprt_request_init(struct rpc_task *task); |
| static int xprt_request_prepare(struct rpc_rqst *req); |
| |
| static DEFINE_SPINLOCK(xprt_list_lock); |
| static LIST_HEAD(xprt_list); |
| |
| static unsigned long xprt_request_timeout(const struct rpc_rqst *req) |
| { |
| unsigned long timeout = jiffies + req->rq_timeout; |
| |
| if (time_before(timeout, req->rq_majortimeo)) |
| return timeout; |
| return req->rq_majortimeo; |
| } |
| |
| /** |
| * 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); |
| |
| static void |
| xprt_class_release(const struct xprt_class *t) |
| { |
| module_put(t->owner); |
| } |
| |
| static const struct xprt_class * |
| xprt_class_find_by_ident_locked(int ident) |
| { |
| const struct xprt_class *t; |
| |
| list_for_each_entry(t, &xprt_list, list) { |
| if (t->ident != ident) |
| continue; |
| if (!try_module_get(t->owner)) |
| continue; |
| return t; |
| } |
| return NULL; |
| } |
| |
| static const struct xprt_class * |
| xprt_class_find_by_ident(int ident) |
| { |
| const struct xprt_class *t; |
| |
| spin_lock(&xprt_list_lock); |
| t = xprt_class_find_by_ident_locked(ident); |
| spin_unlock(&xprt_list_lock); |
| return t; |
| } |
| |
| static const struct xprt_class * |
| xprt_class_find_by_netid_locked(const char *netid) |
| { |
| const struct xprt_class *t; |
| unsigned int i; |
| |
| list_for_each_entry(t, &xprt_list, list) { |
| for (i = 0; t->netid[i][0] != '\0'; i++) { |
| if (strcmp(t->netid[i], netid) != 0) |
| continue; |
| if (!try_module_get(t->owner)) |
| continue; |
| return t; |
| } |
| } |
| return NULL; |
| } |
| |
| static const struct xprt_class * |
| xprt_class_find_by_netid(const char *netid) |
| { |
| const struct xprt_class *t; |
| |
| spin_lock(&xprt_list_lock); |
| t = xprt_class_find_by_netid_locked(netid); |
| if (!t) { |
| spin_unlock(&xprt_list_lock); |
| request_module("rpc%s", netid); |
| spin_lock(&xprt_list_lock); |
| t = xprt_class_find_by_netid_locked(netid); |
| } |
| spin_unlock(&xprt_list_lock); |
| return t; |
| } |
| |
| /** |
| * xprt_find_transport_ident - convert a netid into a transport identifier |
| * @netid: transport to load |
| * |
| * Returns: |
| * > 0: transport identifier |
| * -ENOENT: transport module not available |
| */ |
| int xprt_find_transport_ident(const char *netid) |
| { |
| const struct xprt_class *t; |
| int ret; |
| |
| t = xprt_class_find_by_netid(netid); |
| if (!t) |
| return -ENOENT; |
| ret = t->ident; |
| xprt_class_release(t); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(xprt_find_transport_ident); |
| |
| static void xprt_clear_locked(struct rpc_xprt *xprt) |
| { |
| xprt->snd_task = NULL; |
| if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) |
| clear_bit_unlock(XPRT_LOCKED, &xprt->state); |
| else |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| } |
| |
| /** |
| * 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; |
| |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
| if (task == xprt->snd_task) |
| goto out_locked; |
| goto out_sleep; |
| } |
| if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
| goto out_unlock; |
| xprt->snd_task = task; |
| |
| out_locked: |
| trace_xprt_reserve_xprt(xprt, task); |
| return 1; |
| |
| out_unlock: |
| xprt_clear_locked(xprt); |
| out_sleep: |
| task->tk_status = -EAGAIN; |
| if (RPC_IS_SOFT(task)) |
| rpc_sleep_on_timeout(&xprt->sending, task, NULL, |
| xprt_request_timeout(req)); |
| else |
| rpc_sleep_on(&xprt->sending, task, NULL); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
| |
| 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 |
| * |
| * 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) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
| if (task == xprt->snd_task) |
| goto out_locked; |
| goto out_sleep; |
| } |
| if (req == NULL) { |
| xprt->snd_task = task; |
| goto out_locked; |
| } |
| if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
| goto out_unlock; |
| if (!xprt_need_congestion_window_wait(xprt)) { |
| xprt->snd_task = task; |
| goto out_locked; |
| } |
| out_unlock: |
| xprt_clear_locked(xprt); |
| out_sleep: |
| task->tk_status = -EAGAIN; |
| if (RPC_IS_SOFT(task)) |
| rpc_sleep_on_timeout(&xprt->sending, task, NULL, |
| xprt_request_timeout(req)); |
| else |
| rpc_sleep_on(&xprt->sending, task, NULL); |
| return 0; |
| out_locked: |
| trace_xprt_reserve_cong(xprt, task); |
| return 1; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
| |
| static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| int retval; |
| |
| if (test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == task) |
| return 1; |
| spin_lock(&xprt->transport_lock); |
| retval = xprt->ops->reserve_xprt(xprt, task); |
| spin_unlock(&xprt->transport_lock); |
| return retval; |
| } |
| |
| static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
| { |
| struct rpc_xprt *xprt = data; |
| |
| xprt->snd_task = task; |
| return true; |
| } |
| |
| static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
| { |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
| return; |
| if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
| goto out_unlock; |
| if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
| __xprt_lock_write_func, xprt)) |
| return; |
| out_unlock: |
| xprt_clear_locked(xprt); |
| } |
| |
| static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) |
| { |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
| return; |
| if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
| goto out_unlock; |
| if (xprt_need_congestion_window_wait(xprt)) |
| goto out_unlock; |
| if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
| __xprt_lock_write_func, xprt)) |
| return; |
| out_unlock: |
| xprt_clear_locked(xprt); |
| } |
| |
| /** |
| * 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_clear_locked(xprt); |
| __xprt_lock_write_next(xprt); |
| } |
| trace_xprt_release_xprt(xprt, task); |
| } |
| 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_clear_locked(xprt); |
| __xprt_lock_write_next_cong(xprt); |
| } |
| trace_xprt_release_cong(xprt, task); |
| } |
| EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
| |
| void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| if (xprt->snd_task != task) |
| return; |
| spin_lock(&xprt->transport_lock); |
| xprt->ops->release_xprt(xprt, task); |
| spin_unlock(&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_rqst *req) |
| { |
| if (req->rq_cong) |
| return 1; |
| trace_xprt_get_cong(xprt, req->rq_task); |
| if (RPCXPRT_CONGESTED(xprt)) { |
| xprt_set_congestion_window_wait(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_test_and_clear_congestion_window_wait(xprt); |
| trace_xprt_put_cong(xprt, req->rq_task); |
| __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(&xprt->transport_lock); |
| ret = __xprt_get_cong(xprt, req) != 0; |
| spin_unlock(&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 |
| * |
| * 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); |
| |
| static void xprt_clear_congestion_window_wait_locked(struct rpc_xprt *xprt) |
| { |
| if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state)) |
| __xprt_lock_write_next_cong(xprt); |
| } |
| |
| /* |
| * 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(&xprt->transport_lock); |
| __xprt_lock_write_next_cong(xprt); |
| spin_unlock(&xprt->transport_lock); |
| } |
| } |
| |
| /** |
| * 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 |
| * @xprt: transport |
| * |
| * 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_xprt *xprt) |
| { |
| set_bit(XPRT_WRITE_SPACE, &xprt->state); |
| } |
| EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
| |
| static bool |
| xprt_clear_write_space_locked(struct rpc_xprt *xprt) |
| { |
| if (test_and_clear_bit(XPRT_WRITE_SPACE, &xprt->state)) { |
| __xprt_lock_write_next(xprt); |
| dprintk("RPC: write space: waking waiting task on " |
| "xprt %p\n", xprt); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * 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. |
| */ |
| bool xprt_write_space(struct rpc_xprt *xprt) |
| { |
| bool ret; |
| |
| if (!test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
| return false; |
| spin_lock(&xprt->transport_lock); |
| ret = xprt_clear_write_space_locked(xprt); |
| spin_unlock(&xprt->transport_lock); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(xprt_write_space); |
| |
| static unsigned long xprt_abs_ktime_to_jiffies(ktime_t abstime) |
| { |
| s64 delta = ktime_to_ns(ktime_get() - abstime); |
| return likely(delta >= 0) ? |
| jiffies - nsecs_to_jiffies(delta) : |
| jiffies + nsecs_to_jiffies(-delta); |
| } |
| |
| static unsigned long xprt_calc_majortimeo(struct rpc_rqst *req) |
| { |
| const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
| unsigned long majortimeo = req->rq_timeout; |
| |
| if (to->to_exponential) |
| majortimeo <<= to->to_retries; |
| else |
| majortimeo += to->to_increment * to->to_retries; |
| if (majortimeo > to->to_maxval || majortimeo == 0) |
| majortimeo = to->to_maxval; |
| return majortimeo; |
| } |
| |
| static void xprt_reset_majortimeo(struct rpc_rqst *req) |
| { |
| req->rq_majortimeo += xprt_calc_majortimeo(req); |
| } |
| |
| static void xprt_reset_minortimeo(struct rpc_rqst *req) |
| { |
| req->rq_minortimeo += req->rq_timeout; |
| } |
| |
| static void xprt_init_majortimeo(struct rpc_task *task, struct rpc_rqst *req) |
| { |
| unsigned long time_init; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (likely(xprt && xprt_connected(xprt))) |
| time_init = jiffies; |
| else |
| time_init = xprt_abs_ktime_to_jiffies(task->tk_start); |
| req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
| req->rq_majortimeo = time_init + xprt_calc_majortimeo(req); |
| req->rq_minortimeo = time_init + req->rq_timeout; |
| } |
| |
| /** |
| * 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 (time_before(jiffies, req->rq_minortimeo)) |
| return status; |
| 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(&xprt->transport_lock); |
| rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
| spin_unlock(&xprt->transport_lock); |
| status = -ETIMEDOUT; |
| } |
| xprt_reset_minortimeo(req); |
| |
| 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); |
| unsigned int pflags = memalloc_nofs_save(); |
| |
| trace_xprt_disconnect_auto(xprt); |
| xprt->connect_cookie++; |
| smp_mb__before_atomic(); |
| clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
| xprt->ops->close(xprt); |
| xprt_release_write(xprt, NULL); |
| wake_up_bit(&xprt->state, XPRT_LOCKED); |
| memalloc_nofs_restore(pflags); |
| } |
| |
| /** |
| * xprt_disconnect_done - mark a transport as disconnected |
| * @xprt: transport to flag for disconnect |
| * |
| */ |
| void xprt_disconnect_done(struct rpc_xprt *xprt) |
| { |
| trace_xprt_disconnect_done(xprt); |
| spin_lock(&xprt->transport_lock); |
| xprt_clear_connected(xprt); |
| xprt_clear_write_space_locked(xprt); |
| xprt_clear_congestion_window_wait_locked(xprt); |
| xprt_wake_pending_tasks(xprt, -ENOTCONN); |
| spin_unlock(&xprt->transport_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
| |
| /** |
| * xprt_schedule_autoclose_locked - Try to schedule an autoclose RPC call |
| * @xprt: transport to disconnect |
| */ |
| static void xprt_schedule_autoclose_locked(struct rpc_xprt *xprt) |
| { |
| if (test_and_set_bit(XPRT_CLOSE_WAIT, &xprt->state)) |
| return; |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| else if (xprt->snd_task && !test_bit(XPRT_SND_IS_COOKIE, &xprt->state)) |
| rpc_wake_up_queued_task_set_status(&xprt->pending, |
| xprt->snd_task, -ENOTCONN); |
| } |
| |
| /** |
| * xprt_force_disconnect - force a transport to disconnect |
| * @xprt: transport to disconnect |
| * |
| */ |
| void xprt_force_disconnect(struct rpc_xprt *xprt) |
| { |
| trace_xprt_disconnect_force(xprt); |
| |
| /* Don't race with the test_bit() in xprt_clear_locked() */ |
| spin_lock(&xprt->transport_lock); |
| xprt_schedule_autoclose_locked(xprt); |
| spin_unlock(&xprt->transport_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_force_disconnect); |
| |
| static unsigned int |
| xprt_connect_cookie(struct rpc_xprt *xprt) |
| { |
| return READ_ONCE(xprt->connect_cookie); |
| } |
| |
| static bool |
| xprt_request_retransmit_after_disconnect(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| return req->rq_connect_cookie != xprt_connect_cookie(xprt) || |
| !xprt_connected(xprt); |
| } |
| |
| /** |
| * 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(&xprt->transport_lock); |
| if (cookie != xprt->connect_cookie) |
| goto out; |
| if (test_bit(XPRT_CLOSING, &xprt->state)) |
| goto out; |
| xprt_schedule_autoclose_locked(xprt); |
| out: |
| spin_unlock(&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) |
| { |
| xprt->last_used = jiffies; |
| if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt)) |
| mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout); |
| } |
| |
| static void |
| xprt_init_autodisconnect(struct timer_list *t) |
| { |
| struct rpc_xprt *xprt = from_timer(xprt, t, timer); |
| |
| if (!RB_EMPTY_ROOT(&xprt->recv_queue)) |
| return; |
| /* Reset xprt->last_used to avoid connect/autodisconnect cycling */ |
| xprt->last_used = jiffies; |
| if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
| return; |
| queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
| } |
| |
| #if IS_ENABLED(CONFIG_FAIL_SUNRPC) |
| static void xprt_inject_disconnect(struct rpc_xprt *xprt) |
| { |
| if (!fail_sunrpc.ignore_client_disconnect && |
| should_fail(&fail_sunrpc.attr, 1)) |
| xprt->ops->inject_disconnect(xprt); |
| } |
| #else |
| static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) |
| { |
| } |
| #endif |
| |
| bool xprt_lock_connect(struct rpc_xprt *xprt, |
| struct rpc_task *task, |
| void *cookie) |
| { |
| bool ret = false; |
| |
| spin_lock(&xprt->transport_lock); |
| if (!test_bit(XPRT_LOCKED, &xprt->state)) |
| goto out; |
| if (xprt->snd_task != task) |
| goto out; |
| set_bit(XPRT_SND_IS_COOKIE, &xprt->state); |
| xprt->snd_task = cookie; |
| ret = true; |
| out: |
| spin_unlock(&xprt->transport_lock); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(xprt_lock_connect); |
| |
| void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) |
| { |
| spin_lock(&xprt->transport_lock); |
| if (xprt->snd_task != cookie) |
| goto out; |
| if (!test_bit(XPRT_LOCKED, &xprt->state)) |
| goto out; |
| xprt->snd_task =NULL; |
| clear_bit(XPRT_SND_IS_COOKIE, &xprt->state); |
| xprt->ops->release_xprt(xprt, NULL); |
| xprt_schedule_autodisconnect(xprt); |
| out: |
| spin_unlock(&xprt->transport_lock); |
| wake_up_bit(&xprt->state, XPRT_LOCKED); |
| } |
| EXPORT_SYMBOL_GPL(xprt_unlock_connect); |
| |
| /** |
| * 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; |
| |
| trace_xprt_connect(xprt); |
| |
| if (!xprt_bound(xprt)) { |
| task->tk_status = -EAGAIN; |
| return; |
| } |
| if (!xprt_lock_write(xprt, task)) |
| return; |
| |
| if (!xprt_connected(xprt) && !test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { |
| task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie; |
| rpc_sleep_on_timeout(&xprt->pending, task, NULL, |
| xprt_request_timeout(task->tk_rqstp)); |
| |
| if (test_bit(XPRT_CLOSING, &xprt->state)) |
| return; |
| if (xprt_test_and_set_connecting(xprt)) |
| return; |
| /* Race breaker */ |
| if (!xprt_connected(xprt)) { |
| xprt->stat.connect_start = jiffies; |
| xprt->ops->connect(xprt, task); |
| } else { |
| xprt_clear_connecting(xprt); |
| task->tk_status = 0; |
| rpc_wake_up_queued_task(&xprt->pending, task); |
| } |
| } |
| xprt_release_write(xprt, task); |
| } |
| |
| /** |
| * xprt_reconnect_delay - compute the wait before scheduling a connect |
| * @xprt: transport instance |
| * |
| */ |
| unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt) |
| { |
| unsigned long start, now = jiffies; |
| |
| start = xprt->stat.connect_start + xprt->reestablish_timeout; |
| if (time_after(start, now)) |
| return start - now; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reconnect_delay); |
| |
| /** |
| * xprt_reconnect_backoff - compute the new re-establish timeout |
| * @xprt: transport instance |
| * @init_to: initial reestablish timeout |
| * |
| */ |
| void xprt_reconnect_backoff(struct rpc_xprt *xprt, unsigned long init_to) |
| { |
| xprt->reestablish_timeout <<= 1; |
| if (xprt->reestablish_timeout > xprt->max_reconnect_timeout) |
| xprt->reestablish_timeout = xprt->max_reconnect_timeout; |
| if (xprt->reestablish_timeout < init_to) |
| xprt->reestablish_timeout = init_to; |
| } |
| EXPORT_SYMBOL_GPL(xprt_reconnect_backoff); |
| |
| enum xprt_xid_rb_cmp { |
| XID_RB_EQUAL, |
| XID_RB_LEFT, |
| XID_RB_RIGHT, |
| }; |
| static enum xprt_xid_rb_cmp |
| xprt_xid_cmp(__be32 xid1, __be32 xid2) |
| { |
| if (xid1 == xid2) |
| return XID_RB_EQUAL; |
| if ((__force u32)xid1 < (__force u32)xid2) |
| return XID_RB_LEFT; |
| return XID_RB_RIGHT; |
| } |
| |
| static struct rpc_rqst * |
| xprt_request_rb_find(struct rpc_xprt *xprt, __be32 xid) |
| { |
| struct rb_node *n = xprt->recv_queue.rb_node; |
| struct rpc_rqst *req; |
| |
| while (n != NULL) { |
| req = rb_entry(n, struct rpc_rqst, rq_recv); |
| switch (xprt_xid_cmp(xid, req->rq_xid)) { |
| case XID_RB_LEFT: |
| n = n->rb_left; |
| break; |
| case XID_RB_RIGHT: |
| n = n->rb_right; |
| break; |
| case XID_RB_EQUAL: |
| return req; |
| } |
| } |
| return NULL; |
| } |
| |
| static void |
| xprt_request_rb_insert(struct rpc_xprt *xprt, struct rpc_rqst *new) |
| { |
| struct rb_node **p = &xprt->recv_queue.rb_node; |
| struct rb_node *n = NULL; |
| struct rpc_rqst *req; |
| |
| while (*p != NULL) { |
| n = *p; |
| req = rb_entry(n, struct rpc_rqst, rq_recv); |
| switch(xprt_xid_cmp(new->rq_xid, req->rq_xid)) { |
| case XID_RB_LEFT: |
| p = &n->rb_left; |
| break; |
| case XID_RB_RIGHT: |
| p = &n->rb_right; |
| break; |
| case XID_RB_EQUAL: |
| WARN_ON_ONCE(new != req); |
| return; |
| } |
| } |
| rb_link_node(&new->rq_recv, n, p); |
| rb_insert_color(&new->rq_recv, &xprt->recv_queue); |
| } |
| |
| static void |
| xprt_request_rb_remove(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| rb_erase(&req->rq_recv, &xprt->recv_queue); |
| } |
| |
| /** |
| * 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 |
| * |
| * Caller holds xprt->queue_lock. |
| */ |
| struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
| { |
| struct rpc_rqst *entry; |
| |
| entry = xprt_request_rb_find(xprt, xid); |
| if (entry != NULL) { |
| trace_xprt_lookup_rqst(xprt, xid, 0); |
| entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime); |
| 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 bool |
| xprt_is_pinned_rqst(struct rpc_rqst *req) |
| { |
| return atomic_read(&req->rq_pin) != 0; |
| } |
| |
| /** |
| * xprt_pin_rqst - Pin a request on the transport receive list |
| * @req: Request to pin |
| * |
| * Caller must ensure this is atomic with the call to xprt_lookup_rqst() |
| * so should be holding xprt->queue_lock. |
| */ |
| void xprt_pin_rqst(struct rpc_rqst *req) |
| { |
| atomic_inc(&req->rq_pin); |
| } |
| EXPORT_SYMBOL_GPL(xprt_pin_rqst); |
| |
| /** |
| * xprt_unpin_rqst - Unpin a request on the transport receive list |
| * @req: Request to pin |
| * |
| * Caller should be holding xprt->queue_lock. |
| */ |
| void xprt_unpin_rqst(struct rpc_rqst *req) |
| { |
| if (!test_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate)) { |
| atomic_dec(&req->rq_pin); |
| return; |
| } |
| if (atomic_dec_and_test(&req->rq_pin)) |
| wake_up_var(&req->rq_pin); |
| } |
| EXPORT_SYMBOL_GPL(xprt_unpin_rqst); |
| |
| static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req) |
| { |
| wait_var_event(&req->rq_pin, !xprt_is_pinned_rqst(req)); |
| } |
| |
| static bool |
| xprt_request_data_received(struct rpc_task *task) |
| { |
| return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && |
| READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) != 0; |
| } |
| |
| static bool |
| xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req) |
| { |
| return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && |
| READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) == 0; |
| } |
| |
| /** |
| * xprt_request_enqueue_receive - Add an request to the receive queue |
| * @task: RPC task |
| * |
| */ |
| int |
| xprt_request_enqueue_receive(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| int ret; |
| |
| if (!xprt_request_need_enqueue_receive(task, req)) |
| return 0; |
| |
| ret = xprt_request_prepare(task->tk_rqstp); |
| if (ret) |
| return ret; |
| spin_lock(&xprt->queue_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 */ |
| xprt_request_rb_insert(xprt, req); |
| set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate); |
| spin_unlock(&xprt->queue_lock); |
| |
| /* Turn off autodisconnect */ |
| del_singleshot_timer_sync(&xprt->timer); |
| return 0; |
| } |
| |
| /** |
| * xprt_request_dequeue_receive_locked - Remove a request from the receive queue |
| * @task: RPC task |
| * |
| * Caller must hold xprt->queue_lock. |
| */ |
| static void |
| xprt_request_dequeue_receive_locked(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) |
| xprt_request_rb_remove(req->rq_xprt, req); |
| } |
| |
| /** |
| * xprt_update_rtt - Update RPC RTT statistics |
| * @task: RPC request that recently completed |
| * |
| * Caller holds xprt->queue_lock. |
| */ |
| 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); |
| } |
| } |
| EXPORT_SYMBOL_GPL(xprt_update_rtt); |
| |
| /** |
| * 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 xprt->queue_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; |
| |
| xprt->stat.recvs++; |
| |
| 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; |
| xprt_request_dequeue_receive_locked(task); |
| 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; |
| |
| trace_xprt_timer(xprt, req->rq_xid, task->tk_status); |
| if (!req->rq_reply_bytes_recvd) { |
| if (xprt->ops->timer) |
| xprt->ops->timer(xprt, task); |
| } else |
| task->tk_status = 0; |
| } |
| |
| /** |
| * xprt_wait_for_reply_request_def - wait for reply |
| * @task: pointer to rpc_task |
| * |
| * 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, |
| * and put the task to sleep on the pending queue. |
| */ |
| void xprt_wait_for_reply_request_def(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| rpc_sleep_on_timeout(&req->rq_xprt->pending, task, xprt_timer, |
| xprt_request_timeout(req)); |
| } |
| EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_def); |
| |
| /** |
| * xprt_wait_for_reply_request_rtt - wait for reply using RTT estimator |
| * @task: pointer to rpc_task |
| * |
| * Set a request's retransmit timeout using the RTT estimator, |
| * and put the task to sleep on the pending queue. |
| */ |
| void xprt_wait_for_reply_request_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; |
| unsigned long timeout; |
| |
| timeout = rpc_calc_rto(rtt, timer); |
| timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; |
| if (timeout > max_timeout || timeout == 0) |
| timeout = max_timeout; |
| rpc_sleep_on_timeout(&req->rq_xprt->pending, task, xprt_timer, |
| jiffies + timeout); |
| } |
| EXPORT_SYMBOL_GPL(xprt_wait_for_reply_request_rtt); |
| |
| /** |
| * xprt_request_wait_receive - wait for the reply to an RPC request |
| * @task: RPC task about to send a request |
| * |
| */ |
| void xprt_request_wait_receive(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (!test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) |
| return; |
| /* |
| * Sleep on the pending queue if we're expecting a reply. |
| * The spinlock ensures atomicity between the test of |
| * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on(). |
| */ |
| spin_lock(&xprt->queue_lock); |
| if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) { |
| xprt->ops->wait_for_reply_request(task); |
| /* |
| * Send an extra queue wakeup call if the |
| * connection was dropped in case the call to |
| * rpc_sleep_on() raced. |
| */ |
| if (xprt_request_retransmit_after_disconnect(task)) |
| rpc_wake_up_queued_task_set_status(&xprt->pending, |
| task, -ENOTCONN); |
| } |
| spin_unlock(&xprt->queue_lock); |
| } |
| |
| static bool |
| xprt_request_need_enqueue_transmit(struct rpc_task *task, struct rpc_rqst *req) |
| { |
| return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate); |
| } |
| |
| /** |
| * xprt_request_enqueue_transmit - queue a task for transmission |
| * @task: pointer to rpc_task |
| * |
| * Add a task to the transmission queue. |
| */ |
| void |
| xprt_request_enqueue_transmit(struct rpc_task *task) |
| { |
| struct rpc_rqst *pos, *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (xprt_request_need_enqueue_transmit(task, req)) { |
| req->rq_bytes_sent = 0; |
| spin_lock(&xprt->queue_lock); |
| /* |
| * 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 if (!req->rq_seqno) { |
| 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); |
| out: |
| atomic_long_inc(&xprt->xmit_queuelen); |
| set_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate); |
| spin_unlock(&xprt->queue_lock); |
| } |
| } |
| |
| /** |
| * xprt_request_dequeue_transmit_locked - remove a task from the transmission queue |
| * @task: pointer to rpc_task |
| * |
| * Remove a task from the transmission queue |
| * Caller must hold xprt->queue_lock |
| */ |
| static void |
| xprt_request_dequeue_transmit_locked(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| if (!test_and_clear_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
| return; |
| if (!list_empty(&req->rq_xmit)) { |
| list_del(&req->rq_xmit); |
| if (!list_empty(&req->rq_xmit2)) { |
| struct rpc_rqst *next = list_first_entry(&req->rq_xmit2, |
| struct rpc_rqst, rq_xmit2); |
| list_del(&req->rq_xmit2); |
| list_add_tail(&next->rq_xmit, &next->rq_xprt->xmit_queue); |
| } |
| } else |
| list_del(&req->rq_xmit2); |
| atomic_long_dec(&req->rq_xprt->xmit_queuelen); |
| } |
| |
| /** |
| * xprt_request_dequeue_transmit - remove a task from the transmission queue |
| * @task: pointer to rpc_task |
| * |
| * Remove a task from the transmission queue |
| */ |
| static void |
| xprt_request_dequeue_transmit(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| spin_lock(&xprt->queue_lock); |
| xprt_request_dequeue_transmit_locked(task); |
| spin_unlock(&xprt->queue_lock); |
| } |
| |
| /** |
| * xprt_request_dequeue_xprt - remove a task from the transmit+receive queue |
| * @task: pointer to rpc_task |
| * |
| * Remove a task from the transmit and receive queues, and ensure that |
| * it is not pinned by the receive work item. |
| */ |
| void |
| xprt_request_dequeue_xprt(struct rpc_task *task) |
| { |
| struct rpc_rqst *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) || |
| test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) || |
| xprt_is_pinned_rqst(req)) { |
| spin_lock(&xprt->queue_lock); |
| xprt_request_dequeue_transmit_locked(task); |
| xprt_request_dequeue_receive_locked(task); |
| while (xprt_is_pinned_rqst(req)) { |
| set_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate); |
| spin_unlock(&xprt->queue_lock); |
| xprt_wait_on_pinned_rqst(req); |
| spin_lock(&xprt->queue_lock); |
| clear_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate); |
| } |
| spin_unlock(&xprt->queue_lock); |
| } |
| } |
| |
| /** |
| * xprt_request_prepare - prepare an encoded request for transport |
| * @req: pointer to rpc_rqst |
| * |
| * Calls into the transport layer to do whatever is needed to prepare |
| * the request for transmission or receive. |
| * Returns error, or zero. |
| */ |
| static int |
| xprt_request_prepare(struct rpc_rqst *req) |
| { |
| struct rpc_xprt *xprt = req->rq_xprt; |
| |
| if (xprt->ops->prepare_request) |
| return xprt->ops->prepare_request(req); |
| return 0; |
| } |
| |
| /** |
| * xprt_request_need_retransmit - Test if a task needs retransmission |
| * @task: pointer to rpc_task |
| * |
| * Test for whether a connection breakage requires the task to retransmit |
| */ |
| bool |
| xprt_request_need_retransmit(struct rpc_task *task) |
| { |
| return xprt_request_retransmit_after_disconnect(task); |
| } |
| |
| /** |
| * 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; |
| |
| if (!xprt_lock_write(xprt, task)) { |
| /* Race breaker: someone may have transmitted us */ |
| if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
| rpc_wake_up_queued_task_set_status(&xprt->sending, |
| task, 0); |
| return false; |
| |
| } |
| if (atomic_read(&xprt->swapper)) |
| /* This will be clear in __rpc_execute */ |
| current->flags |= PF_MEMALLOC; |
| return true; |
| } |
| |
| void xprt_end_transmit(struct rpc_task *task) |
| { |
| struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
| |
| xprt_inject_disconnect(xprt); |
| xprt_release_write(xprt, task); |
| } |
| |
| /** |
| * xprt_request_transmit - send an RPC request on a transport |
| * @req: pointer to request to transmit |
| * @snd_task: RPC task that owns the transport lock |
| * |
| * This performs the transmission of a single request. |
| * Note that if the request is not the same as snd_task, then it |
| * does need to be pinned. |
| * Returns '0' on success. |
| */ |
| static int |
| xprt_request_transmit(struct rpc_rqst *req, struct rpc_task *snd_task) |
| { |
| struct rpc_xprt *xprt = req->rq_xprt; |
| struct rpc_task *task = req->rq_task; |
| unsigned int connect_cookie; |
| int is_retrans = RPC_WAS_SENT(task); |
| int status; |
| |
| if (!req->rq_bytes_sent) { |
| if (xprt_request_data_received(task)) { |
| status = 0; |
| goto out_dequeue; |
| } |
| /* Verify that our message lies in the RPCSEC_GSS window */ |
| if (rpcauth_xmit_need_reencode(task)) { |
| status = -EBADMSG; |
| goto out_dequeue; |
| } |
| if (RPC_SIGNALLED(task)) { |
| status = -ERESTARTSYS; |
| goto out_dequeue; |
| } |
| } |
| |
| /* |
| * Update req->rq_ntrans before transmitting to avoid races with |
| * xprt_update_rtt(), which needs to know that it is recording a |
| * reply to the first transmission. |
| */ |
| req->rq_ntrans++; |
| |
| trace_rpc_xdr_sendto(task, &req->rq_snd_buf); |
| connect_cookie = xprt->connect_cookie; |
| status = xprt->ops->send_request(req); |
| if (status != 0) { |
| req->rq_ntrans--; |
| trace_xprt_transmit(req, status); |
| return status; |
| } |
| |
| if (is_retrans) { |
| task->tk_client->cl_stats->rpcretrans++; |
| trace_xprt_retransmit(req); |
| } |
| |
| xprt_inject_disconnect(xprt); |
| |
| task->tk_flags |= RPC_TASK_SENT; |
| spin_lock(&xprt->transport_lock); |
| |
| 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; |
| spin_unlock(&xprt->transport_lock); |
| |
| req->rq_connect_cookie = connect_cookie; |
| out_dequeue: |
| trace_xprt_transmit(req, status); |
| xprt_request_dequeue_transmit(task); |
| rpc_wake_up_queued_task_set_status(&xprt->sending, task, status); |
| return status; |
| } |
| |
| /** |
| * xprt_transmit - send an RPC request on a transport |
| * @task: controlling RPC task |
| * |
| * Attempts to drain the transmit queue. On exit, either the transport |
| * signalled an error that needs to be handled before transmission can |
| * resume, or @task finished transmitting, and detected that it already |
| * received a reply. |
| */ |
| void |
| xprt_transmit(struct rpc_task *task) |
| { |
| struct rpc_rqst *next, *req = task->tk_rqstp; |
| struct rpc_xprt *xprt = req->rq_xprt; |
| int status; |
| |
| spin_lock(&xprt->queue_lock); |
| for (;;) { |
| next = list_first_entry_or_null(&xprt->xmit_queue, |
| struct rpc_rqst, rq_xmit); |
| if (!next) |
| break; |
| xprt_pin_rqst(next); |
| spin_unlock(&xprt->queue_lock); |
| status = xprt_request_transmit(next, task); |
| if (status == -EBADMSG && next != req) |
| status = 0; |
| spin_lock(&xprt->queue_lock); |
| xprt_unpin_rqst(next); |
| if (status < 0) { |
| if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
| task->tk_status = status; |
| break; |
| } |
| /* Was @task transmitted, and has it received a reply? */ |
| if (xprt_request_data_received(task) && |
| !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
| break; |
| cond_resched_lock(&xprt->queue_lock); |
| } |
| spin_unlock(&xprt->queue_lock); |
| } |
| |
| static void xprt_complete_request_init(struct rpc_task *task) |
| { |
| if (task->tk_rqstp) |
| xprt_request_init(task); |
| } |
| |
| void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| set_bit(XPRT_CONGESTED, &xprt->state); |
| rpc_sleep_on(&xprt->backlog, task, xprt_complete_request_init); |
| } |
| EXPORT_SYMBOL_GPL(xprt_add_backlog); |
| |
| static bool __xprt_set_rq(struct rpc_task *task, void *data) |
| { |
| struct rpc_rqst *req = data; |
| |
| if (task->tk_rqstp == NULL) { |
| memset(req, 0, sizeof(*req)); /* mark unused */ |
| task->tk_rqstp = req; |
| return true; |
| } |
| return false; |
| } |
| |
| bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| if (rpc_wake_up_first(&xprt->backlog, __xprt_set_rq, req) == NULL) { |
| clear_bit(XPRT_CONGESTED, &xprt->state); |
| return false; |
| } |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(xprt_wake_up_backlog); |
| |
| 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)) { |
| xprt_add_backlog(xprt, task); |
| ret = true; |
| } |
| spin_unlock(&xprt->reserve_lock); |
| out: |
| return ret; |
| } |
| |
| static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt) |
| { |
| struct rpc_rqst *req = ERR_PTR(-EAGAIN); |
| |
| if (xprt->num_reqs >= xprt->max_reqs) |
| goto out; |
| ++xprt->num_reqs; |
| spin_unlock(&xprt->reserve_lock); |
| req = kzalloc(sizeof(*req), rpc_task_gfp_mask()); |
| spin_lock(&xprt->reserve_lock); |
| if (req != NULL) |
| goto out; |
| --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 (xprt->num_reqs > xprt->min_reqs) { |
| --xprt->num_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); |
| 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"); |
| fallthrough; |
| default: |
| task->tk_status = -EAGAIN; |
| } |
| spin_unlock(&xprt->reserve_lock); |
| return; |
| out_init_req: |
| xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots, |
| xprt->num_reqs); |
| spin_unlock(&xprt->reserve_lock); |
| |
| task->tk_status = 0; |
| task->tk_rqstp = req; |
| } |
| EXPORT_SYMBOL_GPL(xprt_alloc_slot); |
| |
| void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
| { |
| spin_lock(&xprt->reserve_lock); |
| if (!xprt_wake_up_backlog(xprt, req) && |
| !xprt_dynamic_free_slot(xprt, req)) { |
| memset(req, 0, sizeof(*req)); /* mark unused */ |
| list_add(&req->rq_list, &xprt->free); |
| } |
| spin_unlock(&xprt->reserve_lock); |
| } |
| EXPORT_SYMBOL_GPL(xprt_free_slot); |
| |
| 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); |
| } |
| } |
| |
| static DEFINE_IDA(rpc_xprt_ids); |
| |
| void xprt_cleanup_ids(void) |
| { |
| ida_destroy(&rpc_xprt_ids); |
| } |
| |
| static int xprt_alloc_id(struct rpc_xprt *xprt) |
| { |
| int id; |
| |
| id = ida_simple_get(&rpc_xprt_ids, 0, 0, GFP_KERNEL); |
| if (id < 0) |
| return id; |
| |
| xprt->id = id; |
| return 0; |
| } |
| |
| static void xprt_free_id(struct rpc_xprt *xprt) |
| { |
| ida_simple_remove(&rpc_xprt_ids, xprt->id); |
| } |
| |
| 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_alloc_id(xprt); |
| 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; |
| 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_track(xprt->xprt_net, &xprt->ns_tracker); |
| xprt_free_all_slots(xprt); |
| xprt_free_id(xprt); |
| rpc_sysfs_xprt_destroy(xprt); |
| kfree_rcu(xprt, rcu); |
| } |
| EXPORT_SYMBOL_GPL(xprt_free); |
| |
| static void |
| xprt_init_connect_cookie(struct rpc_rqst *req, struct rpc_xprt *xprt) |
| { |
| req->rq_connect_cookie = xprt_connect_cookie(xprt) - 1; |
| } |
| |
| static __be32 |
| xprt_alloc_xid(struct rpc_xprt *xprt) |
| { |
| __be32 xid; |
| |
| spin_lock(&xprt->reserve_lock); |
| xid = (__force __be32)xprt->xid++; |
| spin_unlock(&xprt->reserve_lock); |
| return xid; |
| } |
| |
| static 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 = task->tk_xprt; |
| struct rpc_rqst *req = task->tk_rqstp; |
| |
| req->rq_task = task; |
| req->rq_xprt = xprt; |
| req->rq_buffer = NULL; |
| req->rq_xid = xprt_alloc_xid(xprt); |
| xprt_init_connect_cookie(req, xprt); |
| 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_snd_buf.bvec = NULL; |
| req->rq_rcv_buf.bvec = NULL; |
| req->rq_release_snd_buf = NULL; |
| xprt_init_majortimeo(task, req); |
| |
| trace_xprt_reserve(req); |
| } |
| |
| static void |
| xprt_do_reserve(struct rpc_xprt *xprt, struct rpc_task *task) |
| { |
| xprt->ops->alloc_slot(xprt, task); |
| if (task->tk_rqstp != NULL) |
| xprt_request_init(task); |
| } |
| |
| /** |
| * 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_status = -EAGAIN; |
| if (!xprt_throttle_congested(xprt, task)) |
| xprt_do_reserve(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_status = -EAGAIN; |
| xprt_do_reserve(xprt, task); |
| } |
| |
| /** |
| * 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; |
| xprt_release_write(xprt, task); |
| } |
| return; |
| } |
| |
| xprt = req->rq_xprt; |
| xprt_request_dequeue_xprt(task); |
| spin_lock(&xprt->transport_lock); |
| xprt->ops->release_xprt(xprt, task); |
| if (xprt->ops->release_request) |
| xprt->ops->release_request(task); |
| xprt_schedule_autodisconnect(xprt); |
| spin_unlock(&xprt->transport_lock); |
| if (req->rq_buffer) |
| xprt->ops->buf_free(task); |
| xdr_free_bvec(&req->rq_rcv_buf); |
| xdr_free_bvec(&req->rq_snd_buf); |
| if (req->rq_cred != NULL) |
| put_rpccred(req->rq_cred); |
| if (req->rq_release_snd_buf) |
| req->rq_release_snd_buf(req); |
| |
| task->tk_rqstp = NULL; |
| if (likely(!bc_prealloc(req))) |
| xprt->ops->free_slot(xprt, req); |
| else |
| xprt_free_bc_request(req); |
| } |
| |
| #ifdef CONFIG_SUNRPC_BACKCHANNEL |
| void |
| xprt_init_bc_request(struct rpc_rqst *req, struct rpc_task *task) |
| { |
| struct xdr_buf *xbufp = &req->rq_snd_buf; |
| |
| task->tk_rqstp = req; |
| req->rq_task = task; |
| xprt_init_connect_cookie(req, req->rq_xprt); |
| /* |
| * Set up the xdr_buf length. |
| * This also indicates that the buffer is XDR encoded already. |
| */ |
| xbufp->len = xbufp->head[0].iov_len + xbufp->page_len + |
| xbufp->tail[0].iov_len; |
| } |
| #endif |
| |
| 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); |
| spin_lock_init(&xprt->queue_lock); |
| |
| INIT_LIST_HEAD(&xprt->free); |
| xprt->recv_queue = RB_ROOT; |
| INIT_LIST_HEAD(&xprt->xmit_queue); |
| #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_wait_queue(&xprt->sending, "xprt_sending"); |
| rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
| |
| xprt_init_xid(xprt); |
| |
| xprt->xprt_net = get_net_track(net, &xprt->ns_tracker, GFP_KERNEL); |
| } |
| |
| /** |
| * 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; |
| const struct xprt_class *t; |
| |
| t = xprt_class_find_by_ident(args->ident); |
| if (!t) { |
| dprintk("RPC: transport (%d) not supported\n", args->ident); |
| return ERR_PTR(-EIO); |
| } |
| |
| xprt = t->setup(args); |
| xprt_class_release(t); |
| |
| if (IS_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)) |
| timer_setup(&xprt->timer, xprt_init_autodisconnect, 0); |
| else |
| timer_setup(&xprt->timer, NULL, 0); |
| |
| 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); |
| |
| trace_xprt_create(xprt); |
| out: |
| return xprt; |
| } |
| |
| static void xprt_destroy_cb(struct work_struct *work) |
| { |
| struct rpc_xprt *xprt = |
| container_of(work, struct rpc_xprt, task_cleanup); |
| |
| trace_xprt_destroy(xprt); |
| |
| 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); |
| kfree(xprt->servername); |
| /* |
| * Destroy any existing back channel |
| */ |
| xprt_destroy_backchannel(xprt, UINT_MAX); |
| |
| /* |
| * Tear down transport state and free the rpc_xprt |
| */ |
| xprt->ops->destroy(xprt); |
| } |
| |
| /** |
| * xprt_destroy - destroy an RPC transport, killing off all requests. |
| * @xprt: transport to destroy |
| * |
| */ |
| static void xprt_destroy(struct rpc_xprt *xprt) |
| { |
| /* |
| * Exclude transport connect/disconnect handlers and autoclose |
| */ |
| wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); |
| |
| /* |
| * xprt_schedule_autodisconnect() can run after XPRT_LOCKED |
| * is cleared. We use ->transport_lock to ensure the mod_timer() |
| * can only run *before* del_time_sync(), never after. |
| */ |
| spin_lock(&xprt->transport_lock); |
| del_timer_sync(&xprt->timer); |
| spin_unlock(&xprt->transport_lock); |
| |
| /* |
| * Destroy sockets etc from the system workqueue so they can |
| * safely flush receive work running on rpciod. |
| */ |
| INIT_WORK(&xprt->task_cleanup, xprt_destroy_cb); |
| schedule_work(&xprt->task_cleanup); |
| } |
| |
| 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); |