path: root/net/sunrpc/clnt.c

/*
 *  linux/net/sunrpc/clnt.c
 *
 *  This file contains the high-level RPC interface.
 *  It is modeled as a finite state machine to support both synchronous
 *  and asynchronous requests.
 *
 *  -	RPC header generation and argument serialization.
 *  -	Credential refresh.
 *  -	TCP connect handling.
 *  -	Retry of operation when it is suspected the operation failed because
 *	of uid squashing on the server, or when the credentials were stale
 *	and need to be refreshed, or when a packet was damaged in transit.
 *	This may be have to be moved to the VFS layer.
 *
 *  NB: BSD uses a more intelligent approach to guessing when a request
 *  or reply has been lost by keeping the RTO estimate for each procedure.
 *  We currently make do with a constant timeout value.
 *
 *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
 *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <asm/system.h>

#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/metrics.h>


#define RPC_SLACK_SPACE		(1024)	/* total overkill */

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_CALL
#endif

static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);


static void	call_start(struct rpc_task *task);
static void	call_reserve(struct rpc_task *task);
static void	call_reserveresult(struct rpc_task *task);
static void	call_allocate(struct rpc_task *task);
static void	call_encode(struct rpc_task *task);
static void	call_decode(struct rpc_task *task);
static void	call_bind(struct rpc_task *task);
static void	call_bind_status(struct rpc_task *task);
static void	call_transmit(struct rpc_task *task);
static void	call_status(struct rpc_task *task);
static void	call_transmit_status(struct rpc_task *task);
static void	call_refresh(struct rpc_task *task);
static void	call_refreshresult(struct rpc_task *task);
static void	call_timeout(struct rpc_task *task);
static void	call_connect(struct rpc_task *task);
static void	call_connect_status(struct rpc_task *task);
static u32 *	call_header(struct rpc_task *task);
static u32 *	call_verify(struct rpc_task *task);


static int
rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
{
	static uint32_t clntid;
	int error;

	clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
	clnt->cl_dentry = ERR_PTR(-ENOENT);
	if (dir_name ==