mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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feb8ca37cc
If the XPRT_CLOSE_WAIT flag is set, we need to ensure that we call xprt->ops->close() while holding xprt_lock_write() before we can start reconnecting. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
1164 lines
31 KiB
C
1164 lines
31 KiB
C
/*
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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/sunrpc/clnt.h>
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#include <linux/sunrpc/metrics.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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#ifdef RPC_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_request_init(struct rpc_task *, struct rpc_xprt *);
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static inline void do_xprt_reserve(struct rpc_task *);
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static void xprt_connect_status(struct rpc_task *task);
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static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
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static DEFINE_SPINLOCK(xprt_list_lock);
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static LIST_HEAD(xprt_list);
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/*
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* The transport code maintains an estimate on the maximum number of out-
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* standing RPC requests, using a smoothed version of the congestion
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* avoidance implemented in 44BSD. This is basically the Van Jacobson
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* congestion algorithm: If a retransmit occurs, the congestion window is
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* halved; otherwise, it is incremented by 1/cwnd when
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*
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* - a reply is received and
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* - a full number of requests are outstanding and
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* - the congestion window hasn't been updated recently.
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*/
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#define RPC_CWNDSHIFT (8U)
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#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
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#define RPC_INITCWND RPC_CWNDSCALE
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#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
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#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
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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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char module_name[sizeof t->name + 5];
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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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strcpy(module_name, "xprt");
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strncat(module_name, transport_name, sizeof t->name);
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result = request_module(module_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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/**
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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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*
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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_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = req->rq_xprt;
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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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return 1;
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if (task == NULL)
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return 0;
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goto out_sleep;
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}
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xprt->snd_task = task;
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if (req) {
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req->rq_bytes_sent = 0;
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req->rq_ntrans++;
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}
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return 1;
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out_sleep:
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dprintk("RPC: %5u failed to lock transport %p\n",
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task->tk_pid, xprt);
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task->tk_timeout = 0;
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task->tk_status = -EAGAIN;
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if (req && req->rq_ntrans)
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rpc_sleep_on(&xprt->resend, task, NULL);
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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 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) || xprt->shutdown) {
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smp_mb__before_clear_bit();
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clear_bit(XPRT_LOCKED, &xprt->state);
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smp_mb__after_clear_bit();
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} else
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queue_work(rpciod_workqueue, &xprt->task_cleanup);
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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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*/
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int xprt_reserve_xprt_cong(struct rpc_task *task)
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{
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struct rpc_xprt *xprt = task->tk_xprt;
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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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return 1;
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goto out_sleep;
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}
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if (__xprt_get_cong(xprt, task)) {
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xprt->snd_task = task;
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if (req) {
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req->rq_bytes_sent = 0;
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req->rq_ntrans++;
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}
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return 1;
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}
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xprt_clear_locked(xprt);
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out_sleep:
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dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
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task->tk_timeout = 0;
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task->tk_status = -EAGAIN;
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if (req && req->rq_ntrans)
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rpc_sleep_on(&xprt->resend, task, NULL);
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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_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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spin_lock_bh(&xprt->transport_lock);
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retval = xprt->ops->reserve_xprt(task);
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spin_unlock_bh(&xprt->transport_lock);
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return retval;
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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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struct rpc_task *task;
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struct rpc_rqst *req;
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
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return;
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task = rpc_wake_up_next(&xprt->resend);
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if (!task) {
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task = rpc_wake_up_next(&xprt->sending);
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if (!task)
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goto out_unlock;
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}
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req = task->tk_rqstp;
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xprt->snd_task = task;
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if (req) {
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req->rq_bytes_sent = 0;
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req->rq_ntrans++;
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}
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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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struct rpc_task *task;
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if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
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return;
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if (RPCXPRT_CONGESTED(xprt))
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goto out_unlock;
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task = rpc_wake_up_next(&xprt->resend);
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if (!task) {
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task = rpc_wake_up_next(&xprt->sending);
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if (!task)
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goto out_unlock;
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}
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if (__xprt_get_cong(xprt, task)) {
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struct rpc_rqst *req = task->tk_rqstp;
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xprt->snd_task = task;
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if (req) {
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req->rq_bytes_sent = 0;
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req->rq_ntrans++;
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}
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return;
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}
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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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}
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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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}
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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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spin_lock_bh(&xprt->transport_lock);
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xprt->ops->release_xprt(xprt, task);
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spin_unlock_bh(&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_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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if (req->rq_cong)
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return 1;
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dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
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task->tk_pid, xprt->cong, xprt->cwnd);
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if (RPCXPRT_CONGESTED(xprt))
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return 0;
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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_lock_write_next_cong(xprt);
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}
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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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__xprt_put_cong(task->tk_xprt, task->tk_rqstp);
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}
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EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
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|
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/**
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* xprt_adjust_cwnd - adjust transport congestion window
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* @task: recently completed RPC request used to adjust window
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* @result: result code of completed RPC request
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*
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* We use a time-smoothed congestion estimator to avoid heavy oscillation.
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*/
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void xprt_adjust_cwnd(struct rpc_task *task, int result)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = task->tk_xprt;
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unsigned long cwnd = xprt->cwnd;
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if (result >= 0 && cwnd <= xprt->cong) {
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/* The (cwnd >> 1) term makes sure
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* the result gets rounded properly. */
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cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
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if (cwnd > RPC_MAXCWND(xprt))
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cwnd = RPC_MAXCWND(xprt);
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__xprt_lock_write_next_cong(xprt);
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} else if (result == -ETIMEDOUT) {
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cwnd >>= 1;
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if (cwnd < RPC_CWNDSCALE)
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cwnd = RPC_CWNDSCALE;
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}
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dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
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xprt->cong, xprt->cwnd, cwnd);
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xprt->cwnd = cwnd;
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__xprt_put_cong(xprt, req);
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}
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EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
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|
|
|
/**
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* xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
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* @xprt: transport with waiting tasks
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* @status: result code to plant in each task before waking it
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*
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*/
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void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
|
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{
|
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if (status < 0)
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rpc_wake_up_status(&xprt->pending, status);
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else
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rpc_wake_up(&xprt->pending);
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}
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EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
|
|
|
|
/**
|
|
* xprt_wait_for_buffer_space - wait for transport output buffer to clear
|
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* @task: task to be put to sleep
|
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* @action: function pointer to be executed after wait
|
|
*/
|
|
void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
task->tk_timeout = req->rq_timeout;
|
|
rpc_sleep_on(&xprt->pending, task, action);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
|
|
|
|
/**
|
|
* xprt_write_space - wake the task waiting for transport output buffer space
|
|
* @xprt: transport with waiting tasks
|
|
*
|
|
* Can be called in a soft IRQ context, so xprt_write_space never sleeps.
|
|
*/
|
|
void xprt_write_space(struct rpc_xprt *xprt)
|
|
{
|
|
if (unlikely(xprt->shutdown))
|
|
return;
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (xprt->snd_task) {
|
|
dprintk("RPC: write space: waking waiting task on "
|
|
"xprt %p\n", xprt);
|
|
rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
|
|
}
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_write_space);
|
|
|
|
/**
|
|
* xprt_set_retrans_timeout_def - set a request's retransmit timeout
|
|
* @task: task whose timeout is to be set
|
|
*
|
|
* Set a request's retransmit timeout based on the transport's
|
|
* default timeout parameters. Used by transports that don't adjust
|
|
* the retransmit timeout based on round-trip time estimation.
|
|
*/
|
|
void xprt_set_retrans_timeout_def(struct rpc_task *task)
|
|
{
|
|
task->tk_timeout = task->tk_rqstp->rq_timeout;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
|
|
|
|
/*
|
|
* xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
|
|
* @task: task whose timeout is to be set
|
|
*
|
|
* Set a request's retransmit timeout using the RTT estimator.
|
|
*/
|
|
void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
|
|
{
|
|
int timer = task->tk_msg.rpc_proc->p_timer;
|
|
struct rpc_clnt *clnt = task->tk_client;
|
|
struct rpc_rtt *rtt = clnt->cl_rtt;
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
unsigned long max_timeout = clnt->cl_timeout->to_maxval;
|
|
|
|
task->tk_timeout = rpc_calc_rto(rtt, timer);
|
|
task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
|
|
if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
|
|
task->tk_timeout = max_timeout;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
|
|
|
|
static void xprt_reset_majortimeo(struct rpc_rqst *req)
|
|
{
|
|
const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
|
|
|
|
req->rq_majortimeo = req->rq_timeout;
|
|
if (to->to_exponential)
|
|
req->rq_majortimeo <<= to->to_retries;
|
|
else
|
|
req->rq_majortimeo += to->to_increment * to->to_retries;
|
|
if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
|
|
req->rq_majortimeo = to->to_maxval;
|
|
req->rq_majortimeo += jiffies;
|
|
}
|
|
|
|
/**
|
|
* xprt_adjust_timeout - adjust timeout values for next retransmit
|
|
* @req: RPC request containing parameters to use for the adjustment
|
|
*
|
|
*/
|
|
int xprt_adjust_timeout(struct rpc_rqst *req)
|
|
{
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
|
|
int status = 0;
|
|
|
|
if (time_before(jiffies, req->rq_majortimeo)) {
|
|
if (to->to_exponential)
|
|
req->rq_timeout <<= 1;
|
|
else
|
|
req->rq_timeout += to->to_increment;
|
|
if (to->to_maxval && req->rq_timeout >= to->to_maxval)
|
|
req->rq_timeout = to->to_maxval;
|
|
req->rq_retries++;
|
|
} else {
|
|
req->rq_timeout = to->to_initval;
|
|
req->rq_retries = 0;
|
|
xprt_reset_majortimeo(req);
|
|
/* Reset the RTT counters == "slow start" */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
status = -ETIMEDOUT;
|
|
}
|
|
|
|
if (req->rq_timeout == 0) {
|
|
printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
|
|
req->rq_timeout = 5 * HZ;
|
|
}
|
|
return status;
|
|
}
|
|
|
|
static void xprt_autoclose(struct work_struct *work)
|
|
{
|
|
struct rpc_xprt *xprt =
|
|
container_of(work, struct rpc_xprt, task_cleanup);
|
|
|
|
xprt->ops->close(xprt);
|
|
clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
|
|
xprt_release_write(xprt, NULL);
|
|
}
|
|
|
|
/**
|
|
* xprt_disconnect_done - mark a transport as disconnected
|
|
* @xprt: transport to flag for disconnect
|
|
*
|
|
*/
|
|
void xprt_disconnect_done(struct rpc_xprt *xprt)
|
|
{
|
|
dprintk("RPC: disconnected transport %p\n", xprt);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
xprt_clear_connected(xprt);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_disconnect_done);
|
|
|
|
/**
|
|
* xprt_force_disconnect - force a transport to disconnect
|
|
* @xprt: transport to disconnect
|
|
*
|
|
*/
|
|
void xprt_force_disconnect(struct rpc_xprt *xprt)
|
|
{
|
|
/* Don't race with the test_bit() in xprt_clear_locked() */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
|
|
/* Try to schedule an autoclose RPC call */
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
/**
|
|
* xprt_conditional_disconnect - force a transport to disconnect
|
|
* @xprt: transport to disconnect
|
|
* @cookie: 'connection cookie'
|
|
*
|
|
* This attempts to break the connection if and only if 'cookie' matches
|
|
* the current transport 'connection cookie'. It ensures that we don't
|
|
* try to break the connection more than once when we need to retransmit
|
|
* a batch of RPC requests.
|
|
*
|
|
*/
|
|
void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
|
|
{
|
|
/* Don't race with the test_bit() in xprt_clear_locked() */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (cookie != xprt->connect_cookie)
|
|
goto out;
|
|
if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
|
|
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(rpciod_workqueue, &xprt->task_cleanup);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
out:
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static void
|
|
xprt_init_autodisconnect(unsigned long data)
|
|
{
|
|
struct rpc_xprt *xprt = (struct rpc_xprt *)data;
|
|
|
|
spin_lock(&xprt->transport_lock);
|
|
if (!list_empty(&xprt->recv) || xprt->shutdown)
|
|
goto out_abort;
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
|
|
goto out_abort;
|
|
spin_unlock(&xprt->transport_lock);
|
|
set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
return;
|
|
out_abort:
|
|
spin_unlock(&xprt->transport_lock);
|
|
}
|
|
|
|
/**
|
|
* 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_xprt;
|
|
|
|
dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
|
|
xprt, (xprt_connected(xprt) ? "is" : "is not"));
|
|
|
|
if (!xprt_bound(xprt)) {
|
|
task->tk_status = -EAGAIN;
|
|
return;
|
|
}
|
|
if (!xprt_lock_write(xprt, task))
|
|
return;
|
|
|
|
if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
|
|
xprt->ops->close(xprt);
|
|
|
|
if (xprt_connected(xprt))
|
|
xprt_release_write(xprt, task);
|
|
else {
|
|
if (task->tk_rqstp)
|
|
task->tk_rqstp->rq_bytes_sent = 0;
|
|
|
|
task->tk_timeout = xprt->connect_timeout;
|
|
rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
|
|
xprt->stat.connect_start = jiffies;
|
|
xprt->ops->connect(task);
|
|
}
|
|
return;
|
|
}
|
|
|
|
static void xprt_connect_status(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
if (task->tk_status == 0) {
|
|
xprt->stat.connect_count++;
|
|
xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
|
|
dprintk("RPC: %5u xprt_connect_status: connection established\n",
|
|
task->tk_pid);
|
|
return;
|
|
}
|
|
|
|
switch (task->tk_status) {
|
|
case -EAGAIN:
|
|
dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
|
|
break;
|
|
case -ETIMEDOUT:
|
|
dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
|
|
"out\n", task->tk_pid);
|
|
break;
|
|
default:
|
|
dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
|
|
"server %s\n", task->tk_pid, -task->tk_status,
|
|
task->tk_client->cl_server);
|
|
xprt_release_write(xprt, task);
|
|
task->tk_status = -EIO;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xprt_lookup_rqst - find an RPC request corresponding to an XID
|
|
* @xprt: transport on which the original request was transmitted
|
|
* @xid: RPC XID of incoming reply
|
|
*
|
|
*/
|
|
struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
|
|
{
|
|
struct list_head *pos;
|
|
|
|
list_for_each(pos, &xprt->recv) {
|
|
struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list);
|
|
if (entry->rq_xid == xid)
|
|
return entry;
|
|
}
|
|
|
|
dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
|
|
ntohl(xid));
|
|
xprt->stat.bad_xids++;
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
|
|
|
|
/**
|
|
* xprt_update_rtt - update an RPC client's RTT state after receiving a reply
|
|
* @task: RPC request that recently completed
|
|
*
|
|
*/
|
|
void xprt_update_rtt(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_rtt *rtt = task->tk_client->cl_rtt;
|
|
unsigned timer = task->tk_msg.rpc_proc->p_timer;
|
|
|
|
if (timer) {
|
|
if (req->rq_ntrans == 1)
|
|
rpc_update_rtt(rtt, timer,
|
|
(long)jiffies - req->rq_xtime);
|
|
rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
|
|
}
|
|
}
|
|
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 transport lock.
|
|
*/
|
|
void xprt_complete_rqst(struct rpc_task *task, int copied)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
|
|
task->tk_pid, ntohl(req->rq_xid), copied);
|
|
|
|
xprt->stat.recvs++;
|
|
task->tk_rtt = (long)jiffies - req->rq_xtime;
|
|
|
|
list_del_init(&req->rq_list);
|
|
req->rq_private_buf.len = copied;
|
|
/* Ensure all writes are done before we update */
|
|
/* req->rq_reply_bytes_recvd */
|
|
smp_wmb();
|
|
req->rq_reply_bytes_recvd = copied;
|
|
rpc_wake_up_queued_task(&xprt->pending, task);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_complete_rqst);
|
|
|
|
static void xprt_timer(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
if (task->tk_status != -ETIMEDOUT)
|
|
return;
|
|
dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (!req->rq_reply_bytes_recvd) {
|
|
if (xprt->ops->timer)
|
|
xprt->ops->timer(task);
|
|
} else
|
|
task->tk_status = 0;
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static inline int xprt_has_timer(struct rpc_xprt *xprt)
|
|
{
|
|
return xprt->idle_timeout != 0;
|
|
}
|
|
|
|
/**
|
|
* xprt_prepare_transmit - reserve the transport before sending a request
|
|
* @task: RPC task about to send a request
|
|
*
|
|
*/
|
|
int xprt_prepare_transmit(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
int err = 0;
|
|
|
|
dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) {
|
|
err = req->rq_reply_bytes_recvd;
|
|
goto out_unlock;
|
|
}
|
|
if (!xprt->ops->reserve_xprt(task))
|
|
err = -EAGAIN;
|
|
out_unlock:
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
return err;
|
|
}
|
|
|
|
void xprt_end_transmit(struct rpc_task *task)
|
|
{
|
|
xprt_release_write(task->tk_rqstp->rq_xprt, task);
|
|
}
|
|
|
|
/**
|
|
* xprt_transmit - send an RPC request on a transport
|
|
* @task: controlling RPC task
|
|
*
|
|
* We have to copy the iovec because sendmsg fiddles with its contents.
|
|
*/
|
|
void xprt_transmit(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
int status;
|
|
|
|
dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
|
|
|
|
if (!req->rq_reply_bytes_recvd) {
|
|
if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
|
|
/*
|
|
* Add to the list only if we're expecting a reply
|
|
*/
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
/* Update the softirq receive buffer */
|
|
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
|
|
sizeof(req->rq_private_buf));
|
|
/* Add request to the receive list */
|
|
list_add_tail(&req->rq_list, &xprt->recv);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
xprt_reset_majortimeo(req);
|
|
/* Turn off autodisconnect */
|
|
del_singleshot_timer_sync(&xprt->timer);
|
|
}
|
|
} else if (!req->rq_bytes_sent)
|
|
return;
|
|
|
|
req->rq_connect_cookie = xprt->connect_cookie;
|
|
req->rq_xtime = jiffies;
|
|
status = xprt->ops->send_request(task);
|
|
if (status != 0) {
|
|
task->tk_status = status;
|
|
return;
|
|
}
|
|
|
|
dprintk("RPC: %5u xmit complete\n", task->tk_pid);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
|
|
xprt->ops->set_retrans_timeout(task);
|
|
|
|
xprt->stat.sends++;
|
|
xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
|
|
xprt->stat.bklog_u += xprt->backlog.qlen;
|
|
|
|
/* Don't race with disconnect */
|
|
if (!xprt_connected(xprt))
|
|
task->tk_status = -ENOTCONN;
|
|
else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) {
|
|
/*
|
|
* Sleep on the pending queue since
|
|
* we're expecting a reply.
|
|
*/
|
|
rpc_sleep_on(&xprt->pending, task, xprt_timer);
|
|
}
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static inline void do_xprt_reserve(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
task->tk_status = 0;
|
|
if (task->tk_rqstp)
|
|
return;
|
|
if (!list_empty(&xprt->free)) {
|
|
struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
|
|
list_del_init(&req->rq_list);
|
|
task->tk_rqstp = req;
|
|
xprt_request_init(task, xprt);
|
|
return;
|
|
}
|
|
dprintk("RPC: waiting for request slot\n");
|
|
task->tk_status = -EAGAIN;
|
|
task->tk_timeout = 0;
|
|
rpc_sleep_on(&xprt->backlog, task, NULL);
|
|
}
|
|
|
|
/**
|
|
* xprt_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.
|
|
*/
|
|
void xprt_reserve(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
task->tk_status = -EIO;
|
|
spin_lock(&xprt->reserve_lock);
|
|
do_xprt_reserve(task);
|
|
spin_unlock(&xprt->reserve_lock);
|
|
}
|
|
|
|
static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
|
|
{
|
|
return xprt->xid++;
|
|
}
|
|
|
|
static inline void xprt_init_xid(struct rpc_xprt *xprt)
|
|
{
|
|
xprt->xid = net_random();
|
|
}
|
|
|
|
static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
|
|
req->rq_timeout = task->tk_client->cl_timeout->to_initval;
|
|
req->rq_task = task;
|
|
req->rq_xprt = xprt;
|
|
req->rq_buffer = NULL;
|
|
req->rq_xid = xprt_alloc_xid(xprt);
|
|
req->rq_release_snd_buf = NULL;
|
|
xprt_reset_majortimeo(req);
|
|
dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
|
|
req, ntohl(req->rq_xid));
|
|
}
|
|
|
|
/**
|
|
* xprt_release - release an RPC request slot
|
|
* @task: task which is finished with the slot
|
|
*
|
|
*/
|
|
void xprt_release(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt;
|
|
struct rpc_rqst *req;
|
|
int is_bc_request;
|
|
|
|
if (!(req = task->tk_rqstp))
|
|
return;
|
|
|
|
/* Preallocated backchannel request? */
|
|
is_bc_request = bc_prealloc(req);
|
|
|
|
xprt = req->rq_xprt;
|
|
rpc_count_iostats(task);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
xprt->ops->release_xprt(xprt, task);
|
|
if (xprt->ops->release_request)
|
|
xprt->ops->release_request(task);
|
|
if (!list_empty(&req->rq_list))
|
|
list_del(&req->rq_list);
|
|
xprt->last_used = jiffies;
|
|
if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
|
|
mod_timer(&xprt->timer,
|
|
xprt->last_used + xprt->idle_timeout);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
if (!bc_prealloc(req))
|
|
xprt->ops->buf_free(req->rq_buffer);
|
|
task->tk_rqstp = NULL;
|
|
if (req->rq_release_snd_buf)
|
|
req->rq_release_snd_buf(req);
|
|
|
|
/*
|
|
* Early exit if this is a backchannel preallocated request.
|
|
* There is no need to have it added to the RPC slot list.
|
|
*/
|
|
if (is_bc_request)
|
|
return;
|
|
|
|
memset(req, 0, sizeof(*req)); /* mark unused */
|
|
|
|
dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
|
|
|
|
spin_lock(&xprt->reserve_lock);
|
|
list_add(&req->rq_list, &xprt->free);
|
|
rpc_wake_up_next(&xprt->backlog);
|
|
spin_unlock(&xprt->reserve_lock);
|
|
}
|
|
|
|
/**
|
|
* 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 rpc_rqst *req;
|
|
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);
|
|
printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
|
|
return ERR_PTR(-EIO);
|
|
|
|
found:
|
|
xprt = t->setup(args);
|
|
if (IS_ERR(xprt)) {
|
|
dprintk("RPC: xprt_create_transport: failed, %ld\n",
|
|
-PTR_ERR(xprt));
|
|
return xprt;
|
|
}
|
|
|
|
kref_init(&xprt->kref);
|
|
spin_lock_init(&xprt->transport_lock);
|
|
spin_lock_init(&xprt->reserve_lock);
|
|
|
|
INIT_LIST_HEAD(&xprt->free);
|
|
INIT_LIST_HEAD(&xprt->recv);
|
|
#if defined(CONFIG_NFS_V4_1)
|
|
spin_lock_init(&xprt->bc_pa_lock);
|
|
INIT_LIST_HEAD(&xprt->bc_pa_list);
|
|
#endif /* CONFIG_NFS_V4_1 */
|
|
|
|
INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
|
|
if (xprt_has_timer(xprt))
|
|
setup_timer(&xprt->timer, xprt_init_autodisconnect,
|
|
(unsigned long)xprt);
|
|
else
|
|
init_timer(&xprt->timer);
|
|
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_wait_queue(&xprt->resend, "xprt_resend");
|
|
rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
|
|
|
|
/* initialize free list */
|
|
for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--)
|
|
list_add(&req->rq_list, &xprt->free);
|
|
|
|
xprt_init_xid(xprt);
|
|
|
|
dprintk("RPC: created transport %p with %u slots\n", xprt,
|
|
xprt->max_reqs);
|
|
return xprt;
|
|
}
|
|
|
|
/**
|
|
* xprt_destroy - destroy an RPC transport, killing off all requests.
|
|
* @kref: kref for the transport to destroy
|
|
*
|
|
*/
|
|
static void xprt_destroy(struct kref *kref)
|
|
{
|
|
struct rpc_xprt *xprt = container_of(kref, struct rpc_xprt, kref);
|
|
|
|
dprintk("RPC: destroying transport %p\n", xprt);
|
|
xprt->shutdown = 1;
|
|
del_timer_sync(&xprt->timer);
|
|
|
|
rpc_destroy_wait_queue(&xprt->binding);
|
|
rpc_destroy_wait_queue(&xprt->pending);
|
|
rpc_destroy_wait_queue(&xprt->sending);
|
|
rpc_destroy_wait_queue(&xprt->resend);
|
|
rpc_destroy_wait_queue(&xprt->backlog);
|
|
/*
|
|
* Tear down transport state and free the rpc_xprt
|
|
*/
|
|
xprt->ops->destroy(xprt);
|
|
}
|
|
|
|
/**
|
|
* xprt_put - release a reference to an RPC transport.
|
|
* @xprt: pointer to the transport
|
|
*
|
|
*/
|
|
void xprt_put(struct rpc_xprt *xprt)
|
|
{
|
|
kref_put(&xprt->kref, xprt_destroy);
|
|
}
|
|
|
|
/**
|
|
* xprt_get - return a reference to an RPC transport.
|
|
* @xprt: pointer to the transport
|
|
*
|
|
*/
|
|
struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
|
|
{
|
|
kref_get(&xprt->kref);
|
|
return xprt;
|
|
}
|