911813d7a1
Refactor: Hoist create/destroy/disconnect tracepoints out of xprtrdma and into the generic RPC client. Some benefits include: - Enable tracing of xprt lifetime events for the socket transport types - Expose the different types of disconnect to help run down issues with lingering connections Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2013 lines
51 KiB
C
2013 lines
51 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/net/sunrpc/xprt.c
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*
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* This is a generic RPC call interface supporting congestion avoidance,
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* and asynchronous calls.
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*
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* The interface works like this:
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*
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* - When a process places a call, it allocates a request slot if
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* one is available. Otherwise, it sleeps on the backlog queue
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* (xprt_reserve).
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* - Next, the caller puts together the RPC message, stuffs it into
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* the request struct, and calls xprt_transmit().
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* - xprt_transmit sends the message and installs the caller on the
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* transport's wait list. At the same time, if a reply is expected,
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* it installs a timer that is run after the packet's timeout has
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* expired.
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* - When a packet arrives, the data_ready handler walks the list of
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* pending requests for that transport. If a matching XID is found, the
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* caller is woken up, and the timer removed.
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* - When no reply arrives within the timeout interval, the timer is
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* fired by the kernel and runs xprt_timer(). It either adjusts the
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* timeout values (minor timeout) or wakes up the caller with a status
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* of -ETIMEDOUT.
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* - When the caller receives a notification from RPC that a reply arrived,
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* it should release the RPC slot, and process the reply.
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* If the call timed out, it may choose to retry the operation by
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* adjusting the initial timeout value, and simply calling rpc_call
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* again.
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*
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* Support for async RPC is done through a set of RPC-specific scheduling
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* primitives that `transparently' work for processes as well as async
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* tasks that rely on callbacks.
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*
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* Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
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*
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* Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com>
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/interrupt.h>
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#include <linux/workqueue.h>
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#include <linux/net.h>
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#include <linux/ktime.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/sunrpc/metrics.h>
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#include <linux/sunrpc/bc_xprt.h>
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#include <linux/rcupdate.h>
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#include <linux/sched/mm.h>
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#include <trace/events/sunrpc.h>
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#include "sunrpc.h"
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/*
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* Local variables
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*/
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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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# define RPCDBG_FACILITY RPCDBG_XPRT
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#endif
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/*
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* Local functions
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*/
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static void xprt_init(struct rpc_xprt *xprt, struct net *net);
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static __be32 xprt_alloc_xid(struct rpc_xprt *xprt);
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static void xprt_destroy(struct rpc_xprt *xprt);
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static DEFINE_SPINLOCK(xprt_list_lock);
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static LIST_HEAD(xprt_list);
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static unsigned long xprt_request_timeout(const struct rpc_rqst *req)
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{
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unsigned long timeout = jiffies + req->rq_timeout;
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if (time_before(timeout, req->rq_majortimeo))
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return timeout;
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return req->rq_majortimeo;
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}
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/**
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* xprt_register_transport - register a transport implementation
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* @transport: transport to register
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*
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* If a transport implementation is loaded as a kernel module, it can
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* call this interface to make itself known to the RPC client.
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*
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* Returns:
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* 0: transport successfully registered
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* -EEXIST: transport already registered
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* -EINVAL: transport module being unloaded
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*/
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int xprt_register_transport(struct xprt_class *transport)
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{
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struct xprt_class *t;
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int result;
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result = -EEXIST;
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spin_lock(&xprt_list_lock);
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list_for_each_entry(t, &xprt_list, list) {
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/* don't register the same transport class twice */
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if (t->ident == transport->ident)
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goto out;
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}
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list_add_tail(&transport->list, &xprt_list);
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printk(KERN_INFO "RPC: Registered %s transport module.\n",
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transport->name);
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result = 0;
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out:
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spin_unlock(&xprt_list_lock);
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return result;
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}
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EXPORT_SYMBOL_GPL(xprt_register_transport);
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/**
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* xprt_unregister_transport - unregister a transport implementation
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* @transport: transport to unregister
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*
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* Returns:
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* 0: transport successfully unregistered
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* -ENOENT: transport never registered
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*/
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int xprt_unregister_transport(struct xprt_class *transport)
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{
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struct xprt_class *t;
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int result;
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result = 0;
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spin_lock(&xprt_list_lock);
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list_for_each_entry(t, &xprt_list, list) {
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if (t == transport) {
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printk(KERN_INFO
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"RPC: Unregistered %s transport module.\n",
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transport->name);
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list_del_init(&transport->list);
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goto out;
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}
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}
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result = -ENOENT;
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out:
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spin_unlock(&xprt_list_lock);
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return result;
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}
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EXPORT_SYMBOL_GPL(xprt_unregister_transport);
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/**
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* xprt_load_transport - load a transport implementation
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* @transport_name: transport to load
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*
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* Returns:
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* 0: transport successfully loaded
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* -ENOENT: transport module not available
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*/
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int xprt_load_transport(const char *transport_name)
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{
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struct xprt_class *t;
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int result;
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result = 0;
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spin_lock(&xprt_list_lock);
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list_for_each_entry(t, &xprt_list, list) {
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if (strcmp(t->name, transport_name) == 0) {
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spin_unlock(&xprt_list_lock);
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goto out;
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}
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}
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spin_unlock(&xprt_list_lock);
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result = request_module("xprt%s", transport_name);
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out:
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return result;
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}
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EXPORT_SYMBOL_GPL(xprt_load_transport);
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static void xprt_clear_locked(struct rpc_xprt *xprt)
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{
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xprt->snd_task = NULL;
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if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) {
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smp_mb__before_atomic();
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clear_bit(XPRT_LOCKED, &xprt->state);
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smp_mb__after_atomic();
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} else
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queue_work(xprtiod_workqueue, &xprt->task_cleanup);
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}
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/**
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* xprt_reserve_xprt - serialize write access to transports
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* @task: task that is requesting access to the transport
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* @xprt: pointer to the target transport
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*
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* This prevents mixing the payload of separate requests, and prevents
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* transport connects from colliding with writes. No congestion control
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* is provided.
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*/
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int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
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if (task == xprt->snd_task)
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goto out_locked;
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goto out_sleep;
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}
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if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
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goto out_unlock;
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xprt->snd_task = task;
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out_locked:
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trace_xprt_reserve_xprt(xprt, task);
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return 1;
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out_unlock:
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xprt_clear_locked(xprt);
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out_sleep:
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task->tk_status = -EAGAIN;
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if (RPC_IS_SOFT(task))
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rpc_sleep_on_timeout(&xprt->sending, task, NULL,
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xprt_request_timeout(req));
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else
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rpc_sleep_on(&xprt->sending, task, NULL);
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return 0;
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}
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EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
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static bool
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xprt_need_congestion_window_wait(struct rpc_xprt *xprt)
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{
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return test_bit(XPRT_CWND_WAIT, &xprt->state);
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}
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static void
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xprt_set_congestion_window_wait(struct rpc_xprt *xprt)
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{
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if (!list_empty(&xprt->xmit_queue)) {
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/* Peek at head of queue to see if it can make progress */
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if (list_first_entry(&xprt->xmit_queue, struct rpc_rqst,
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rq_xmit)->rq_cong)
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return;
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}
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set_bit(XPRT_CWND_WAIT, &xprt->state);
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}
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static void
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xprt_test_and_clear_congestion_window_wait(struct rpc_xprt *xprt)
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{
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if (!RPCXPRT_CONGESTED(xprt))
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clear_bit(XPRT_CWND_WAIT, &xprt->state);
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}
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/*
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* xprt_reserve_xprt_cong - serialize write access to transports
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* @task: task that is requesting access to the transport
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*
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* Same as xprt_reserve_xprt, but Van Jacobson congestion control is
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* integrated into the decision of whether a request is allowed to be
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* woken up and given access to the transport.
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* Note that the lock is only granted if we know there are free slots.
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*/
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int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
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if (task == xprt->snd_task)
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goto out_locked;
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goto out_sleep;
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}
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if (req == NULL) {
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xprt->snd_task = task;
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goto out_locked;
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}
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if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
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goto out_unlock;
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if (!xprt_need_congestion_window_wait(xprt)) {
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xprt->snd_task = task;
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goto out_locked;
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}
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out_unlock:
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xprt_clear_locked(xprt);
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out_sleep:
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task->tk_status = -EAGAIN;
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if (RPC_IS_SOFT(task))
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rpc_sleep_on_timeout(&xprt->sending, task, NULL,
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xprt_request_timeout(req));
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else
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rpc_sleep_on(&xprt->sending, task, NULL);
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return 0;
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out_locked:
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trace_xprt_reserve_cong(xprt, task);
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return 1;
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}
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EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
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static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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int retval;
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if (test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == task)
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return 1;
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spin_lock(&xprt->transport_lock);
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retval = xprt->ops->reserve_xprt(xprt, task);
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spin_unlock(&xprt->transport_lock);
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return retval;
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}
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static bool __xprt_lock_write_func(struct rpc_task *task, void *data)
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{
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struct rpc_xprt *xprt = data;
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xprt->snd_task = task;
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return true;
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}
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static void __xprt_lock_write_next(struct rpc_xprt *xprt)
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{
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
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return;
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if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
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goto out_unlock;
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if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending,
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__xprt_lock_write_func, xprt))
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return;
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out_unlock:
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xprt_clear_locked(xprt);
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}
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static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
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{
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
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return;
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if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
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goto out_unlock;
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if (xprt_need_congestion_window_wait(xprt))
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goto out_unlock;
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if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending,
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__xprt_lock_write_func, xprt))
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return;
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out_unlock:
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xprt_clear_locked(xprt);
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}
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/**
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* xprt_release_xprt - allow other requests to use a transport
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* @xprt: transport with other tasks potentially waiting
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* @task: task that is releasing access to the transport
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*
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* Note that "task" can be NULL. No congestion control is provided.
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*/
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void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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if (xprt->snd_task == task) {
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xprt_clear_locked(xprt);
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__xprt_lock_write_next(xprt);
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}
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trace_xprt_release_xprt(xprt, task);
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}
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EXPORT_SYMBOL_GPL(xprt_release_xprt);
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/**
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* xprt_release_xprt_cong - allow other requests to use a transport
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* @xprt: transport with other tasks potentially waiting
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* @task: task that is releasing access to the transport
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*
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* Note that "task" can be NULL. Another task is awoken to use the
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* transport if the transport's congestion window allows it.
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*/
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void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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if (xprt->snd_task == task) {
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xprt_clear_locked(xprt);
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__xprt_lock_write_next_cong(xprt);
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}
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trace_xprt_release_cong(xprt, task);
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}
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EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
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static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
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{
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if (xprt->snd_task != task)
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return;
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spin_lock(&xprt->transport_lock);
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xprt->ops->release_xprt(xprt, task);
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spin_unlock(&xprt->transport_lock);
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}
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/*
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* Van Jacobson congestion avoidance. Check if the congestion window
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* overflowed. Put the task to sleep if this is the case.
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*/
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static int
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__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
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{
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if (req->rq_cong)
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return 1;
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trace_xprt_get_cong(xprt, req->rq_task);
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if (RPCXPRT_CONGESTED(xprt)) {
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xprt_set_congestion_window_wait(xprt);
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return 0;
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}
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req->rq_cong = 1;
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xprt->cong += RPC_CWNDSCALE;
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return 1;
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}
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/*
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* Adjust the congestion window, and wake up the next task
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* that has been sleeping due to congestion
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*/
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static void
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__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
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{
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if (!req->rq_cong)
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return;
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req->rq_cong = 0;
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xprt->cong -= RPC_CWNDSCALE;
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xprt_test_and_clear_congestion_window_wait(xprt);
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trace_xprt_put_cong(xprt, req->rq_task);
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__xprt_lock_write_next_cong(xprt);
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}
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/**
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* xprt_request_get_cong - Request congestion control credits
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* @xprt: pointer to transport
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* @req: pointer to RPC request
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*
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* Useful for transports that require congestion control.
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*/
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bool
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xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
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{
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bool ret = false;
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if (req->rq_cong)
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return true;
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spin_lock(&xprt->transport_lock);
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ret = __xprt_get_cong(xprt, req) != 0;
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spin_unlock(&xprt->transport_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(xprt_request_get_cong);
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/**
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* xprt_release_rqst_cong - housekeeping when request is complete
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* @task: RPC request that recently completed
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*
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* Useful for transports that require congestion control.
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*/
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void xprt_release_rqst_cong(struct rpc_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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__xprt_put_cong(req->rq_xprt, req);
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}
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EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
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static void xprt_clear_congestion_window_wait_locked(struct rpc_xprt *xprt)
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{
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if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state))
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__xprt_lock_write_next_cong(xprt);
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}
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/*
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* Clear the congestion window wait flag and wake up the next
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* entry on xprt->sending
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*/
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static void
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xprt_clear_congestion_window_wait(struct rpc_xprt *xprt)
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{
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if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state)) {
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spin_lock(&xprt->transport_lock);
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__xprt_lock_write_next_cong(xprt);
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spin_unlock(&xprt->transport_lock);
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}
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}
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/**
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* xprt_adjust_cwnd - adjust transport congestion window
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* @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_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);
|
|
}
|
|
|
|
/**
|
|
* 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(&xprt->transport_lock);
|
|
rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
|
|
spin_unlock(&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);
|
|
unsigned int pflags = memalloc_nofs_save();
|
|
|
|
trace_xprt_disconnect_auto(xprt);
|
|
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_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);
|
|
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);
|
|
else if (xprt->snd_task)
|
|
rpc_wake_up_queued_task_set_status(&xprt->pending,
|
|
xprt->snd_task, -ENOTCONN);
|
|
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;
|
|
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(&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);
|
|
}
|
|
|
|
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;
|
|
xprt->snd_task = cookie;
|
|
ret = true;
|
|
out:
|
|
spin_unlock(&xprt->transport_lock);
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
xprt->ops->release_xprt(xprt, NULL);
|
|
xprt_schedule_autodisconnect(xprt);
|
|
out:
|
|
spin_unlock(&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)) {
|
|
trace_xprt_disconnect_cleanup(xprt);
|
|
xprt->ops->close(xprt);
|
|
}
|
|
|
|
if (!xprt_connected(xprt)) {
|
|
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
|
|
*
|
|
*/
|
|
void
|
|
xprt_request_enqueue_receive(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
if (!xprt_request_need_enqueue_receive(task, req))
|
|
return;
|
|
|
|
xprt_request_prepare(task->tk_rqstp);
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
trace_xprt_complete_rqst(xprt, req->rq_xid, copied);
|
|
|
|
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);
|
|
trace_xprt_enq_xmit(task, 1);
|
|
goto out;
|
|
}
|
|
} else if (RPC_IS_SWAPPER(task)) {
|
|
list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) {
|
|
if (pos->rq_cong || pos->rq_bytes_sent)
|
|
continue;
|
|
if (RPC_IS_SWAPPER(pos->rq_task))
|
|
continue;
|
|
/* Note: req is added _before_ pos */
|
|
list_add_tail(&req->rq_xmit, &pos->rq_xmit);
|
|
INIT_LIST_HEAD(&req->rq_xmit2);
|
|
trace_xprt_enq_xmit(task, 2);
|
|
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);
|
|
trace_xprt_enq_xmit(task, 3);
|
|
goto out;
|
|
}
|
|
}
|
|
list_add_tail(&req->rq_xmit, &xprt->xmit_queue);
|
|
INIT_LIST_HEAD(&req->rq_xmit2);
|
|
trace_xprt_enq_xmit(task, 4);
|
|
out:
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
void
|
|
xprt_request_prepare(struct rpc_rqst *req)
|
|
{
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
if (xprt->ops->prepare_request)
|
|
xprt->ops->prepare_request(req);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
|
|
|
|
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;
|
|
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void xprt_end_transmit(struct rpc_task *task)
|
|
{
|
|
xprt_release_write(task->tk_rqstp->rq_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++;
|
|
|
|
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);
|
|
while (!list_empty(&xprt->xmit_queue)) {
|
|
next = list_first_entry(&xprt->xmit_queue,
|
|
struct rpc_rqst, rq_xmit);
|
|
xprt_pin_rqst(next);
|
|
spin_unlock(&xprt->queue_lock);
|
|
status = xprt_request_transmit(next, task);
|
|
if (status == -EBADMSG && next != req)
|
|
status = 0;
|
|
cond_resched();
|
|
spin_lock(&xprt->queue_lock);
|
|
xprt_unpin_rqst(next);
|
|
if (status == 0) {
|
|
if (!xprt_request_data_received(task) ||
|
|
test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
|
|
continue;
|
|
} else if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
|
|
task->tk_status = status;
|
|
break;
|
|
}
|
|
spin_unlock(&xprt->queue_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)
|
|
{
|
|
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(struct rpc_rqst), GFP_NOFS);
|
|
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");
|
|
/* fall through */
|
|
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_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);
|
|
}
|
|
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);
|
|
}
|
|
}
|
|
|
|
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;
|
|
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);
|
|
|
|
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);
|
|
dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
|
|
req, ntohl(req->rq_xid));
|
|
}
|
|
|
|
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);
|
|
xprt_inject_disconnect(xprt);
|
|
xdr_free_bvec(&req->rq_rcv_buf);
|
|
xdr_free_bvec(&req->rq_snd_buf);
|
|
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->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(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))
|
|
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);
|
|
|
|
del_timer_sync(&xprt->timer);
|
|
|
|
/*
|
|
* 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);
|