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clnt.c
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/*
* 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/kallsyms.h>
#include <linux/mm.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>
#include <linux/in6.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/metrics.h>
#include <linux/sunrpc/bc_xprt.h>
#include "sunrpc.h"
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_CALL
#endif
#define dprint_status(t) \
dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
__func__, t->tk_status)
/*
* All RPC clients are linked into this list
*/
static LIST_HEAD(all_clients);
static DEFINE_SPINLOCK(rpc_client_lock);
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_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);
#if defined(CONFIG_NFS_V4_1)
static void call_bc_transmit(struct rpc_task *task);
#endif /* CONFIG_NFS_V4_1 */
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 __be32 *rpc_encode_header(struct rpc_task *task);
static __be32 *rpc_verify_header(struct rpc_task *task);
static int rpc_ping(struct rpc_clnt *clnt);
static void rpc_register_client(struct rpc_clnt *clnt)
{
spin_lock(&rpc_client_lock);
list_add(&clnt->cl_clients, &all_clients);
spin_unlock(&rpc_client_lock);
}
static void rpc_unregister_client(struct rpc_clnt *clnt)
{
spin_lock(&rpc_client_lock);
list_del(&clnt->cl_clients);
spin_unlock(&rpc_client_lock);
}
static int
rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
{
static uint32_t clntid;
struct nameidata nd;
struct path path;
char name[15];
struct qstr q = {
.name = name,
};
int error;
clnt->cl_path.mnt = ERR_PTR(-ENOENT);
clnt->cl_path.dentry = ERR_PTR(-ENOENT);
if (dir_name == NULL)
return 0;
path.mnt = rpc_get_mount();
if (IS_ERR(path.mnt))
return PTR_ERR(path.mnt);
error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
if (error)
goto err;
for (;;) {
q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
name[sizeof(name) - 1] = '\0';
q.hash = full_name_hash(q.name, q.len);
path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
if (!IS_ERR(path.dentry))
break;
error = PTR_ERR(path.dentry);
if (error != -EEXIST) {
printk(KERN_INFO "RPC: Couldn't create pipefs entry"
" %s/%s, error %d\n",
dir_name, name, error);
goto err_path_put;
}
}
path_put(&nd.path);
clnt->cl_path = path;
return 0;
err_path_put:
path_put(&nd.path);
err:
rpc_put_mount();
return error;
}
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
{
struct rpc_program *program = args->program;
struct rpc_version *version;
struct rpc_clnt *clnt = NULL;
struct rpc_auth *auth;
int err;
size_t len;
/* sanity check the name before trying to print it */
err = -EINVAL;
len = strlen(args->servername);
if (len > RPC_MAXNETNAMELEN)
goto out_no_rpciod;
len++;
dprintk("RPC: creating %s client for %s (xprt %p)\n",
program->name, args->servername, xprt);
err = rpciod_up();
if (err)
goto out_no_rpciod;
err = -EINVAL;
if (!xprt)
goto out_no_xprt;
if (args->version >= program->nrvers)
goto out_err;
version = program->version[args->version];
if (version == NULL)
goto out_err;
err = -ENOMEM;
clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
if (!clnt)
goto out_err;
clnt->cl_parent = clnt;
clnt->cl_server = clnt->cl_inline_name;
if (len > sizeof(clnt->cl_inline_name)) {
char *buf = kmalloc(len, GFP_KERNEL);
if (buf != NULL)
clnt->cl_server = buf;
else
len = sizeof(clnt->cl_inline_name);
}
strlcpy(clnt->cl_server, args->servername, len);
clnt->cl_xprt = xprt;
clnt->cl_procinfo = version->procs;
clnt->cl_maxproc = version->nrprocs;
clnt->cl_protname = program->name;
clnt->cl_prog = args->prognumber ? : program->number;
clnt->cl_vers = version->number;
clnt->cl_stats = program->stats;
clnt->cl_metrics = rpc_alloc_iostats(clnt);
err = -ENOMEM;
if (clnt->cl_metrics == NULL)
goto out_no_stats;
clnt->cl_program = program;
INIT_LIST_HEAD(&clnt->cl_tasks);
spin_lock_init(&clnt->cl_lock);
if (!xprt_bound(clnt->cl_xprt))
clnt->cl_autobind = 1;
clnt->cl_timeout = xprt->timeout;
if (args->timeout != NULL) {
memcpy(&clnt->cl_timeout_default, args->timeout,
sizeof(clnt->cl_timeout_default));
clnt->cl_timeout = &clnt->cl_timeout_default;
}
clnt->cl_rtt = &clnt->cl_rtt_default;
rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
clnt->cl_principal = NULL;
if (args->client_name) {
clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
if (!clnt->cl_principal)
goto out_no_principal;
}
kref_init(&clnt->cl_kref);
err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
if (err < 0)
goto out_no_path;
auth = rpcauth_create(args->authflavor, clnt);
if (IS_ERR(auth)) {
printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
args->authflavor);
err = PTR_ERR(auth);
goto out_no_auth;
}
/* save the nodename */
clnt->cl_nodelen = strlen(init_utsname()->nodename);
if (clnt->cl_nodelen > UNX_MAXNODENAME)
clnt->cl_nodelen = UNX_MAXNODENAME;
memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
rpc_register_client(clnt);
return clnt;
out_no_auth:
if (!IS_ERR(clnt->cl_path.dentry)) {
rpc_remove_client_dir(clnt->cl_path.dentry);
rpc_put_mount();
}
out_no_path:
kfree(clnt->cl_principal);
out_no_principal:
rpc_free_iostats(clnt->cl_metrics);
out_no_stats:
if (clnt->cl_server != clnt->cl_inline_name)
kfree(clnt->cl_server);
kfree(clnt);
out_err:
xprt_put(xprt);
out_no_xprt:
rpciod_down();
out_no_rpciod:
return ERR_PTR(err);
}
/*
* rpc_create - create an RPC client and transport with one call
* @args: rpc_clnt create argument structure
*
* Creates and initializes an RPC transport and an RPC client.
*
* It can ping the server in order to determine if it is up, and to see if
* it supports this program and version. RPC_CLNT_CREATE_NOPING disables
* this behavior so asynchronous tasks can also use rpc_create.
*/
struct rpc_clnt *rpc_create(struct rpc_create_args *args)
{
struct rpc_xprt *xprt;
struct rpc_clnt *clnt;
struct xprt_create xprtargs = {
.ident = args->protocol,
.srcaddr = args->saddress,
.dstaddr = args->address,
.addrlen = args->addrsize,
.bc_xprt = args->bc_xprt,
};
char servername[48];
/*
* If the caller chooses not to specify a hostname, whip
* up a string representation of the passed-in address.
*/
if (args->servername == NULL) {
servername[0] = '\0';
switch (args->address->sa_family) {
case AF_INET: {
struct sockaddr_in *sin =
(struct sockaddr_in *)args->address;
snprintf(servername, sizeof(servername), "%pI4",
&sin->sin_addr.s_addr);
break;
}
case AF_INET6: {
struct sockaddr_in6 *sin =
(struct sockaddr_in6 *)args->address;
snprintf(servername, sizeof(servername), "%pI6",
&sin->sin6_addr);
break;
}
default:
/* caller wants default server name, but
* address family isn't recognized. */
return ERR_PTR(-EINVAL);
}
args->servername = servername;
}
xprt = xprt_create_transport(&xprtargs);
if (IS_ERR(xprt))
return (struct rpc_clnt *)xprt;
/*
* By default, kernel RPC client connects from a reserved port.
* CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
* but it is always enabled for rpciod, which handles the connect
* operation.
*/
xprt->resvport = 1;
if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
xprt->resvport = 0;
clnt = rpc_new_client(args, xprt);
if (IS_ERR(clnt))
return clnt;
if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
int err = rpc_ping(clnt);
if (err != 0) {
rpc_shutdown_client(clnt);
return ERR_PTR(err);
}
}
clnt->cl_softrtry = 1;
if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
clnt->cl_softrtry = 0;
if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
clnt->cl_autobind = 1;
if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
clnt->cl_discrtry = 1;
if (!(args->flags & RPC_CLNT_CREATE_QUIET))
clnt->cl_chatty = 1;
return clnt;
}
EXPORT_SYMBOL_GPL(rpc_create);
/*
* This function clones the RPC client structure. It allows us to share the
* same transport while varying parameters such as the authentication
* flavour.
*/
struct rpc_clnt *
rpc_clone_client(struct rpc_clnt *clnt)
{
struct rpc_clnt *new;
int err = -ENOMEM;
new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
if (!new)
goto out_no_clnt;
new->cl_parent = clnt;
/* Turn off autobind on clones */
new->cl_autobind = 0;
INIT_LIST_HEAD(&new->cl_tasks);
spin_lock_init(&new->cl_lock);
rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
new->cl_metrics = rpc_alloc_iostats(clnt);
if (new->cl_metrics == NULL)
goto out_no_stats;
if (clnt->cl_principal) {
new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
if (new->cl_principal == NULL)
goto out_no_principal;
}
kref_init(&new->cl_kref);
err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
if (err != 0)
goto out_no_path;
if (new->cl_auth)
atomic_inc(&new->cl_auth->au_count);
xprt_get(clnt->cl_xprt);
kref_get(&clnt->cl_kref);
rpc_register_client(new);
rpciod_up();
return new;
out_no_path:
kfree(new->cl_principal);
out_no_principal:
rpc_free_iostats(new->cl_metrics);
out_no_stats:
kfree(new);
out_no_clnt:
dprintk("RPC: %s: returned error %d\n", __func__, err);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(rpc_clone_client);
/*
* Properly shut down an RPC client, terminating all outstanding
* requests.
*/
void rpc_shutdown_client(struct rpc_clnt *clnt)
{
dprintk("RPC: shutting down %s client for %s\n",
clnt->cl_protname, clnt->cl_server);
while (!list_empty(&clnt->cl_tasks)) {
rpc_killall_tasks(clnt);
wait_event_timeout(destroy_wait,
list_empty(&clnt->cl_tasks), 1*HZ);
}
rpc_release_client(clnt);
}
EXPORT_SYMBOL_GPL(rpc_shutdown_client);
/*
* Free an RPC client
*/
static void
rpc_free_client(struct kref *kref)
{
struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
dprintk("RPC: destroying %s client for %s\n",
clnt->cl_protname, clnt->cl_server);
if (!IS_ERR(clnt->cl_path.dentry)) {
rpc_remove_client_dir(clnt->cl_path.dentry);
rpc_put_mount();
}
if (clnt->cl_parent != clnt) {
rpc_release_client(clnt->cl_parent);
goto out_free;
}
if (clnt->cl_server != clnt->cl_inline_name)
kfree(clnt->cl_server);
out_free:
rpc_unregister_client(clnt);
rpc_free_iostats(clnt->cl_metrics);
kfree(clnt->cl_principal);
clnt->cl_metrics = NULL;
xprt_put(clnt->cl_xprt);
rpciod_down();
kfree(clnt);
}
/*
* Free an RPC client
*/
static void
rpc_free_auth(struct kref *kref)
{
struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
if (clnt->cl_auth == NULL) {
rpc_free_client(kref);
return;
}
/*
* Note: RPCSEC_GSS may need to send NULL RPC calls in order to
* release remaining GSS contexts. This mechanism ensures
* that it can do so safely.
*/
kref_init(kref);
rpcauth_release(clnt->cl_auth);
clnt->cl_auth = NULL;
kref_put(kref, rpc_free_client);
}
/*
* Release reference to the RPC client
*/
void
rpc_release_client(struct rpc_clnt *clnt)
{
dprintk("RPC: rpc_release_client(%p)\n", clnt);
if (list_empty(&clnt->cl_tasks))
wake_up(&destroy_wait);
kref_put(&clnt->cl_kref, rpc_free_auth);
}
/**
* rpc_bind_new_program - bind a new RPC program to an existing client
* @old: old rpc_client
* @program: rpc program to set
* @vers: rpc program version
*
* Clones the rpc client and sets up a new RPC program. This is mainly
* of use for enabling different RPC programs to share the same transport.
* The Sun NFSv2/v3 ACL protocol can do this.
*/
struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
struct rpc_program *program,
u32 vers)
{
struct rpc_clnt *clnt;
struct rpc_version *version;
int err;
BUG_ON(vers >= program->nrvers || !program->version[vers]);
version = program->version[vers];
clnt = rpc_clone_client(old);
if (IS_ERR(clnt))
goto out;
clnt->cl_procinfo = version->procs;
clnt->cl_maxproc = version->nrprocs;
clnt->cl_protname = program->name;
clnt->cl_prog = program->number;
clnt->cl_vers = version->number;
clnt->cl_stats = program->stats;
err = rpc_ping(clnt);
if (err != 0) {
rpc_shutdown_client(clnt);
clnt = ERR_PTR(err);
}
out:
return clnt;
}
EXPORT_SYMBOL_GPL(rpc_bind_new_program);
/*
* Default callback for async RPC calls
*/
static void
rpc_default_callback(struct rpc_task *task, void *data)
{
}
static const struct rpc_call_ops rpc_default_ops = {
.rpc_call_done = rpc_default_callback,
};
/**
* rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
* @task_setup_data: pointer to task initialisation data
*/
struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
{
struct rpc_task *task;
task = rpc_new_task(task_setup_data);
if (IS_ERR(task))
goto out;
atomic_inc(&task->tk_count);
rpc_execute(task);
out:
return task;
}
EXPORT_SYMBOL_GPL(rpc_run_task);
/**
* rpc_call_sync - Perform a synchronous RPC call
* @clnt: pointer to RPC client
* @msg: RPC call parameters
* @flags: RPC call flags
*/
int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
{
struct rpc_task *task;
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
.rpc_message = msg,
.callback_ops = &rpc_default_ops,
.flags = flags,
};
int status;
BUG_ON(flags & RPC_TASK_ASYNC);
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
status = task->tk_status;
rpc_put_task(task);
return status;
}
EXPORT_SYMBOL_GPL(rpc_call_sync);
/**
* rpc_call_async - Perform an asynchronous RPC call
* @clnt: pointer to RPC client
* @msg: RPC call parameters
* @flags: RPC call flags
* @tk_ops: RPC call ops
* @data: user call data
*/
int
rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
const struct rpc_call_ops *tk_ops, void *data)
{
struct rpc_task *task;
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
.rpc_message = msg,
.callback_ops = tk_ops,
.callback_data = data,
.flags = flags|RPC_TASK_ASYNC,
};
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
rpc_put_task(task);
return 0;
}
EXPORT_SYMBOL_GPL(rpc_call_async);
#if defined(CONFIG_NFS_V4_1)
/**
* rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
* rpc_execute against it
* @req: RPC request
* @tk_ops: RPC call ops
*/
struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
const struct rpc_call_ops *tk_ops)
{
struct rpc_task *task;
struct xdr_buf *xbufp = &req->rq_snd_buf;
struct rpc_task_setup task_setup_data = {
.callback_ops = tk_ops,
};
dprintk("RPC: rpc_run_bc_task req= %p\n", req);
/*
* Create an rpc_task to send the data
*/
task = rpc_new_task(&task_setup_data);
if (IS_ERR(task)) {
xprt_free_bc_request(req);
goto out;
}
task->tk_rqstp = req;
/*
* 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;
task->tk_action = call_bc_transmit;
atomic_inc(&task->tk_count);
BUG_ON(atomic_read(&task->tk_count) != 2);
rpc_execute(task);
out:
dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
return task;
}
#endif /* CONFIG_NFS_V4_1 */
void
rpc_call_start(struct rpc_task *task)
{
task->tk_action = call_start;
}
EXPORT_SYMBOL_GPL(rpc_call_start);
/**
* rpc_peeraddr - extract remote peer address from clnt's xprt
* @clnt: RPC client structure
* @buf: target buffer
* @bufsize: length of target buffer
*
* Returns the number of bytes that are actually in the stored address.
*/
size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
{
size_t bytes;
struct rpc_xprt *xprt = clnt->cl_xprt;
bytes = sizeof(xprt->addr);
if (bytes > bufsize)
bytes = bufsize;
memcpy(buf, &clnt->cl_xprt->addr, bytes);
return xprt->addrlen;
}
EXPORT_SYMBOL_GPL(rpc_peeraddr);
/**
* rpc_peeraddr2str - return remote peer address in printable format
* @clnt: RPC client structure
* @format: address format
*
*/
const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
enum rpc_display_format_t format)
{
struct rpc_xprt *xprt = clnt->cl_xprt;
if (xprt->address_strings[format] != NULL)
return xprt->address_strings[format];
else
return "unprintable";
}
EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
void
rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
{
struct rpc_xprt *xprt = clnt->cl_xprt;
if (xprt->ops->set_buffer_size)
xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
}
EXPORT_SYMBOL_GPL(rpc_setbufsize);
/*
* Return size of largest payload RPC client can support, in bytes
*
* For stream transports, this is one RPC record fragment (see RFC
* 1831), as we don't support multi-record requests yet. For datagram
* transports, this is the size of an IP packet minus the IP, UDP, and
* RPC header sizes.
*/
size_t rpc_max_payload(struct rpc_clnt *clnt)
{
return clnt->cl_xprt->max_payload;
}
EXPORT_SYMBOL_GPL(rpc_max_payload);
/**
* rpc_force_rebind - force transport to check that remote port is unchanged
* @clnt: client to rebind
*
*/
void rpc_force_rebind(struct rpc_clnt *clnt)
{
if (clnt->cl_autobind)
xprt_clear_bound(clnt->cl_xprt);
}
EXPORT_SYMBOL_GPL(rpc_force_rebind);
/*
* Restart an (async) RPC call from the call_prepare state.
* Usually called from within the exit handler.
*/
void
rpc_restart_call_prepare(struct rpc_task *task)
{
if (RPC_ASSASSINATED(task))
return;
task->tk_action = rpc_prepare_task;
}
EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
/*
* Restart an (async) RPC call. Usually called from within the
* exit handler.
*/
void
rpc_restart_call(struct rpc_task *task)
{
if (RPC_ASSASSINATED(task))
return;
task->tk_action = call_start;
}
EXPORT_SYMBOL_GPL(rpc_restart_call);
#ifdef RPC_DEBUG
static const char *rpc_proc_name(const struct rpc_task *task)
{
const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
if (proc) {
if (proc->p_name)
return proc->p_name;
else
return "NULL";
} else
return "no proc";
}
#endif
/*
* 0. Initial state
*
* Other FSM states can be visited zero or more times, but
* this state is visited exactly once for each RPC.
*/
static void
call_start(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
clnt->cl_protname, clnt->cl_vers,
rpc_proc_name(task),
(RPC_IS_ASYNC(task) ? "async" : "sync"));
/* Increment call count */
task->tk_msg.rpc_proc->p_count++;
clnt->cl_stats->rpccnt++;
task->tk_action = call_reserve;
}
/*
* 1. Reserve an RPC call slot
*/
static void
call_reserve(struct rpc_task *task)
{
dprint_status(task);
if (!rpcauth_uptodatecred(task)) {
task->tk_action = call_refresh;
return;
}
task->tk_status = 0;
task->tk_action = call_reserveresult;
xprt_reserve(task);
}
/*
* 1b. Grok the result of xprt_reserve()
*/
static void
call_reserveresult(struct rpc_task *task)
{
int status = task->tk_status;
dprint_status(task);
/*
* After a call to xprt_reserve(), we must have either
* a request slot or else an error status.
*/
task->tk_status = 0;
if (status >= 0) {
if (task->tk_rqstp) {
task->tk_action = call_allocate;
return;
}
printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
__func__, status);
rpc_exit(task, -EIO);
return;
}
/*
* Even though there was an error, we may have acquired
* a request slot somehow. Make sure not to leak it.
*/
if (task->tk_rqstp) {
printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
__func__, status);
xprt_release(task);
}
switch (status) {
case -EAGAIN: /* woken up; retry */
task->tk_action = call_reserve;
return;
case -EIO: /* probably a shutdown */
break;
default:
printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
__func__, status);
break;
}
rpc_exit(task, status);
}
/*
* 2. Allocate the buffer. For details, see sched.c:rpc_malloc.
* (Note: buffer memory is freed in xprt_release).
*/
static void
call_allocate(struct rpc_task *task)
{
unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = task->tk_xprt;
struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_bind;
if (req->rq_buffer)
return;
if (proc->p_proc != 0) {
BUG_ON(proc->p_arglen == 0);
if (proc->p_decode != NULL)
BUG_ON(proc->p_replen == 0);
}
/*
* Calculate the size (in quads) of the RPC call
* and reply headers, and convert both values
* to byte sizes.
*/
req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
req->rq_callsize <<= 2;
req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
req->rq_rcvsize <<= 2;
req->rq_buffer = xprt->ops->buf_alloc(task,
req->rq_callsize + req->rq_rcvsize);
if (req->rq_buffer != NULL)
return;
dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
if (RPC_IS_ASYNC(task) || !signalled()) {
task->tk_action = call_allocate;
rpc_delay(task, HZ>>4);
return;
}
rpc_exit(task, -ERESTARTSYS);
}
static inline int
rpc_task_need_encode(struct rpc_task *task)
{
return task->tk_rqstp->rq_snd_buf.len == 0;
}
static inline void
rpc_task_force_reencode(struct rpc_task *task)
{
task->tk_rqstp->rq_snd_buf.len = 0;
task->tk_rqstp->rq_bytes_sent = 0;
}
static inline void
rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
{
buf->head[0].iov_base = start;
buf->head[0].iov_len = len;
buf->tail[0].iov_len = 0;
buf->page_len = 0;
buf->flags = 0;
buf->len = 0;
buf->buflen = len;
}
/*
* 3. Encode arguments of an RPC call
*/
static void
rpc_xdr_encode(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
kxdrproc_t encode;
__be32 *p;
dprint_status(task);
rpc_xdr_buf_init(&req->rq_snd_buf,
req->rq_buffer,
req->rq_callsize);
rpc_xdr_buf_init(&req->rq_rcv_buf,
(char *)req->rq_buffer + req->rq_callsize,
req->rq_rcvsize);
p = rpc_encode_header(task);
if (p == NULL) {
printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
rpc_exit(task, -EIO);
return;
}
encode = task->tk_msg.rpc_proc->p_encode;
if (encode == NULL)
return;
task->tk_status = rpcauth_wrap_req(task, encode, req, p,
task->tk_msg.rpc_argp);
}
/*
* 4. Get the server port number if not yet set