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linux-pinenote/net/sunrpc/clnt.c
Trond Myklebust d07ba8422f SUNRPC: Avoid deep recursion in rpc_release_client 
In cases where an rpc client has a parent hierarchy, then
rpc_free_client may end up calling rpc_release_client() on the
parent, thus recursing back into rpc_free_client. If the hierarchy
is deep enough, then we can get into situations where the stack
simply overflows.

The fix is to have rpc_release_client() loop so that it can take
care of the parent rpc client hierarchy without needing to
recurse.

Reported-by: Jeff Layton <jlayton@redhat.com>
Reported-by: Weston Andros Adamson <dros@netapp.com>
Reported-by: Bruce Fields <bfields@fieldses.org>
Link: http://lkml.kernel.org/r/2C73011F-0939-434C-9E4D-13A1EB1403D7@netapp.com
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-11-12 18:56:57 -05:00

2437 lines
58 KiB
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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.
*
* Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
* Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
*/
#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/rcupdate.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/un.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/metrics.h>
#include <linux/sunrpc/bc_xprt.h>
#include <trace/events/sunrpc.h>
#include "sunrpc.h"
#include "netns.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 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_SUNRPC_BACKCHANNEL)
static void call_bc_transmit(struct rpc_task *task);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
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)
{
struct net *net = rpc_net_ns(clnt);
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
spin_lock(&sn->rpc_client_lock);
list_add(&clnt->cl_clients, &sn->all_clients);
spin_unlock(&sn->rpc_client_lock);
}
static void rpc_unregister_client(struct rpc_clnt *clnt)
{
struct net *net = rpc_net_ns(clnt);
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
spin_lock(&sn->rpc_client_lock);
list_del(&clnt->cl_clients);
spin_unlock(&sn->rpc_client_lock);
}
static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
{
rpc_remove_client_dir(clnt);
}
static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
{
struct net *net = rpc_net_ns(clnt);
struct super_block *pipefs_sb;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
__rpc_clnt_remove_pipedir(clnt);
rpc_put_sb_net(net);
}
}
static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
struct rpc_clnt *clnt)
{
static uint32_t clntid;
const char *dir_name = clnt->cl_program->pipe_dir_name;
char name[15];
struct dentry *dir, *dentry;
dir = rpc_d_lookup_sb(sb, dir_name);
if (dir == NULL) {
pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
return dir;
}
for (;;) {
snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
name[sizeof(name) - 1] = '\0';
dentry = rpc_create_client_dir(dir, name, clnt);
if (!IS_ERR(dentry))
break;
if (dentry == ERR_PTR(-EEXIST))
continue;
printk(KERN_INFO "RPC: Couldn't create pipefs entry"
" %s/%s, error %ld\n",
dir_name, name, PTR_ERR(dentry));
break;
}
dput(dir);
return dentry;
}
static int
rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
{
struct dentry *dentry;
if (clnt->cl_program->pipe_dir_name != NULL) {
dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
return 0;
}
static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
{
if (clnt->cl_program->pipe_dir_name == NULL)
return 1;
switch (event) {
case RPC_PIPEFS_MOUNT:
if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
return 1;
if (atomic_read(&clnt->cl_count) == 0)
return 1;
break;
case RPC_PIPEFS_UMOUNT:
if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
return 1;
break;
}
return 0;
}
static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
struct super_block *sb)
{
struct dentry *dentry;
int err = 0;
switch (event) {
case RPC_PIPEFS_MOUNT:
dentry = rpc_setup_pipedir_sb(sb, clnt);
if (!dentry)
return -ENOENT;
if (IS_ERR(dentry))
return PTR_ERR(dentry);
break;
case RPC_PIPEFS_UMOUNT:
__rpc_clnt_remove_pipedir(clnt);
break;
default:
printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
return -ENOTSUPP;
}
return err;
}
static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
struct super_block *sb)
{
int error = 0;
for (;; clnt = clnt->cl_parent) {
if (!rpc_clnt_skip_event(clnt, event))
error = __rpc_clnt_handle_event(clnt, event, sb);
if (error || clnt == clnt->cl_parent)
break;
}
return error;
}
static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_clnt *clnt;
spin_lock(&sn->rpc_client_lock);
list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
if (rpc_clnt_skip_event(clnt, event))
continue;
spin_unlock(&sn->rpc_client_lock);
return clnt;
}
spin_unlock(&sn->rpc_client_lock);
return NULL;
}
static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
void *ptr)
{
struct super_block *sb = ptr;
struct rpc_clnt *clnt;
int error = 0;
while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
error = __rpc_pipefs_event(clnt, event, sb);
if (error)
break;
}
return error;
}
static struct notifier_block rpc_clients_block = {
.notifier_call = rpc_pipefs_event,
.priority = SUNRPC_PIPEFS_RPC_PRIO,
};
int rpc_clients_notifier_register(void)
{
return rpc_pipefs_notifier_register(&rpc_clients_block);
}
void rpc_clients_notifier_unregister(void)
{
return rpc_pipefs_notifier_unregister(&rpc_clients_block);
}
static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
struct rpc_xprt *xprt,
const struct rpc_timeout *timeout)
{
struct rpc_xprt *old;
spin_lock(&clnt->cl_lock);
old = rcu_dereference_protected(clnt->cl_xprt,
lockdep_is_held(&clnt->cl_lock));
if (!xprt_bound(xprt))
clnt->cl_autobind = 1;
clnt->cl_timeout = timeout;
rcu_assign_pointer(clnt->cl_xprt, xprt);
spin_unlock(&clnt->cl_lock);
return old;
}
static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
{
clnt->cl_nodelen = strlen(nodename);
if (clnt->cl_nodelen > UNX_MAXNODENAME)
clnt->cl_nodelen = UNX_MAXNODENAME;
memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
}
static int rpc_client_register(struct rpc_clnt *clnt,
rpc_authflavor_t pseudoflavor,
const char *client_name)
{
struct rpc_auth_create_args auth_args = {
.pseudoflavor = pseudoflavor,
.target_name = client_name,
};
struct rpc_auth *auth;
struct net *net = rpc_net_ns(clnt);
struct super_block *pipefs_sb;
int err;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
err = rpc_setup_pipedir(pipefs_sb, clnt);
if (err)
goto out;
}
rpc_register_client(clnt);
if (pipefs_sb)
rpc_put_sb_net(net);
auth = rpcauth_create(&auth_args, clnt);
if (IS_ERR(auth)) {
dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
pseudoflavor);
err = PTR_ERR(auth);
goto err_auth;
}
return 0;
err_auth:
pipefs_sb = rpc_get_sb_net(net);
rpc_unregister_client(clnt);
__rpc_clnt_remove_pipedir(clnt);
out:
if (pipefs_sb)
rpc_put_sb_net(net);
return err;
}
static DEFINE_IDA(rpc_clids);
static int rpc_alloc_clid(struct rpc_clnt *clnt)
{
int clid;
clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
if (clid < 0)
return clid;
clnt->cl_clid = clid;
return 0;
}
static void rpc_free_clid(struct rpc_clnt *clnt)
{
ida_simple_remove(&rpc_clids, clnt->cl_clid);
}
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
struct rpc_xprt *xprt,
struct rpc_clnt *parent)
{
const struct rpc_program *program = args->program;
const struct rpc_version *version;
struct rpc_clnt *clnt = NULL;
const struct rpc_timeout *timeout;
int err;
/* sanity check the name before trying to print it */
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 (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 = parent ? : clnt;
err = rpc_alloc_clid(clnt);
if (err)
goto out_no_clid;
clnt->cl_procinfo = version->procs;
clnt->cl_maxproc = version->nrprocs;
clnt->cl_prog = args->prognumber ? : program->number;
clnt->cl_vers = version->number;
clnt->cl_stats = program->stats;
clnt->cl_metrics = rpc_alloc_iostats(clnt);
rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
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);
timeout = xprt->timeout;
if (args->timeout != NULL) {
memcpy(&clnt->cl_timeout_default, args->timeout,
sizeof(clnt->cl_timeout_default));
timeout = &clnt->cl_timeout_default;
}
rpc_clnt_set_transport(clnt, xprt, timeout);
clnt->cl_rtt = &clnt->cl_rtt_default;
rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
atomic_set(&clnt->cl_count, 1);
/* save the nodename */
rpc_clnt_set_nodename(clnt, utsname()->nodename);
err = rpc_client_register(clnt, args->authflavor, args->client_name);
if (err)
goto out_no_path;
if (parent)
atomic_inc(&parent->cl_count);
return clnt;
out_no_path:
rpc_free_iostats(clnt->cl_metrics);
out_no_stats:
rpc_free_clid(clnt);
out_no_clid:
kfree(clnt);
out_err:
rpciod_down();
out_no_rpciod:
xprt_put(xprt);
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 = {
.net = args->net,
.ident = args->protocol,
.srcaddr = args->saddress,
.dstaddr = args->address,
.addrlen = args->addrsize,
.servername = args->servername,
.bc_xprt = args->bc_xprt,
};
char servername[48];
if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
/*
* If the caller chooses not to specify a hostname, whip
* up a string representation of the passed-in address.
*/
if (xprtargs.servername == NULL) {
struct sockaddr_un *sun =
(struct sockaddr_un *)args->address;
struct sockaddr_in *sin =
(struct sockaddr_in *)args->address;
struct sockaddr_in6 *sin6 =
(struct sockaddr_in6 *)args->address;
servername[0] = '\0';
switch (args->address->sa_family) {
case AF_LOCAL:
snprintf(servername, sizeof(servername), "%s",
sun->sun_path);
break;
case AF_INET:
snprintf(servername, sizeof(servername), "%pI4",
&sin->sin_addr.s_addr);
break;
case AF_INET6:
snprintf(servername, sizeof(servername), "%pI6",
&sin6->sin6_addr);
break;
default:
/* caller wants default server name, but
* address family isn't recognized. */
return ERR_PTR(-EINVAL);
}
xprtargs.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, NULL);
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.
*/
static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
struct rpc_clnt *clnt)
{
struct rpc_xprt *xprt;
struct rpc_clnt *new;
int err;
err = -ENOMEM;
rcu_read_lock();
xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
rcu_read_unlock();
if (xprt == NULL)
goto out_err;
args->servername = xprt->servername;
new = rpc_new_client(args, xprt, clnt);
if (IS_ERR(new)) {
err = PTR_ERR(new);
goto out_err;
}
/* Turn off autobind on clones */
new->cl_autobind = 0;
new->cl_softrtry = clnt->cl_softrtry;
new->cl_discrtry = clnt->cl_discrtry;
new->cl_chatty = clnt->cl_chatty;
return new;
out_err:
dprintk("RPC: %s: returned error %d\n", __func__, err);
return ERR_PTR(err);
}
/**
* rpc_clone_client - Clone an RPC client structure
*
* @clnt: RPC client whose parameters are copied
*
* Returns a fresh RPC client or an ERR_PTR.
*/
struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
{
struct rpc_create_args args = {
.program = clnt->cl_program,
.prognumber = clnt->cl_prog,
.version = clnt->cl_vers,
.authflavor = clnt->cl_auth->au_flavor,
};
return __rpc_clone_client(&args, clnt);
}
EXPORT_SYMBOL_GPL(rpc_clone_client);
/**
* rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
*
* @clnt: RPC client whose parameters are copied
* @flavor: security flavor for new client
*
* Returns a fresh RPC client or an ERR_PTR.
*/
struct rpc_clnt *
rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
struct rpc_create_args args = {
.program = clnt->cl_program,
.prognumber = clnt->cl_prog,
.version = clnt->cl_vers,
.authflavor = flavor,
};
return __rpc_clone_client(&args, clnt);
}
EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
/**
* rpc_switch_client_transport: switch the RPC transport on the fly
* @clnt: pointer to a struct rpc_clnt
* @args: pointer to the new transport arguments
* @timeout: pointer to the new timeout parameters
*
* This function allows the caller to switch the RPC transport for the
* rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
* server, for instance. It assumes that the caller has ensured that
* there are no active RPC tasks by using some form of locking.
*
* Returns zero if "clnt" is now using the new xprt. Otherwise a
* negative errno is returned, and "clnt" continues to use the old
* xprt.
*/
int rpc_switch_client_transport(struct rpc_clnt *clnt,
struct xprt_create *args,
const struct rpc_timeout *timeout)
{
const struct rpc_timeout *old_timeo;
rpc_authflavor_t pseudoflavor;
struct rpc_xprt *xprt, *old;
struct rpc_clnt *parent;
int err;
xprt = xprt_create_transport(args);
if (IS_ERR(xprt)) {
dprintk("RPC: failed to create new xprt for clnt %p\n",
clnt);
return PTR_ERR(xprt);
}
pseudoflavor = clnt->cl_auth->au_flavor;
old_timeo = clnt->cl_timeout;
old = rpc_clnt_set_transport(clnt, xprt, timeout);
rpc_unregister_client(clnt);
__rpc_clnt_remove_pipedir(clnt);
/*
* A new transport was created. "clnt" therefore
* becomes the root of a new cl_parent tree. clnt's
* children, if it has any, still point to the old xprt.
*/
parent = clnt->cl_parent;
clnt->cl_parent = clnt;
/*
* The old rpc_auth cache cannot be re-used. GSS
* contexts in particular are between a single
* client and server.
*/
err = rpc_client_register(clnt, pseudoflavor, NULL);
if (err)
goto out_revert;
synchronize_rcu();
if (parent != clnt)
rpc_release_client(parent);
xprt_put(old);
dprintk("RPC: replaced xprt for clnt %p\n", clnt);
return 0;
out_revert:
rpc_clnt_set_transport(clnt, old, old_timeo);
clnt->cl_parent = parent;
rpc_client_register(clnt, pseudoflavor, NULL);
xprt_put(xprt);
dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
return err;
}
EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
/*
* Kill all tasks for the given client.
* XXX: kill their descendants as well?
*/
void rpc_killall_tasks(struct rpc_clnt *clnt)
{
struct rpc_task *rovr;
if (list_empty(&clnt->cl_tasks))
return;
dprintk("RPC: killing all tasks for client %p\n", clnt);
/*
* Spin lock all_tasks to prevent changes...
*/
spin_lock(&clnt->cl_lock);
list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
if (!RPC_IS_ACTIVATED(rovr))
continue;
if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
rovr->tk_flags |= RPC_TASK_KILLED;
rpc_exit(rovr, -EIO);
if (RPC_IS_QUEUED(rovr))
rpc_wake_up_queued_task(rovr->tk_waitqueue,
rovr);
}
}
spin_unlock(&clnt->cl_lock);
}
EXPORT_SYMBOL_GPL(rpc_killall_tasks);
/*
* Properly shut down an RPC client, terminating all outstanding
* requests.
*/
void rpc_shutdown_client(struct rpc_clnt *clnt)
{
might_sleep();
dprintk_rcu("RPC: shutting down %s client for %s\n",
clnt->cl_program->name,
rcu_dereference(clnt->cl_xprt)->servername);
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 struct rpc_clnt *
rpc_free_client(struct rpc_clnt *clnt)
{
struct rpc_clnt *parent = NULL;
dprintk_rcu("RPC: destroying %s client for %s\n",
clnt->cl_program->name,
rcu_dereference(clnt->cl_xprt)->servername);
if (clnt->cl_parent != clnt)
parent = clnt->cl_parent;
rpc_clnt_remove_pipedir(clnt);
rpc_unregister_client(clnt);
rpc_free_iostats(clnt->cl_metrics);
clnt->cl_metrics = NULL;
xprt_put(rcu_dereference_raw(clnt->cl_xprt));
rpciod_down();
rpc_free_clid(clnt);
kfree(clnt);
return parent;
}
/*
* Free an RPC client
*/
static struct rpc_clnt *
rpc_free_auth(struct rpc_clnt *clnt)
{
if (clnt->cl_auth == NULL)
return rpc_free_client(clnt);
/*
* 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.
*/
atomic_inc(&clnt->cl_count);
rpcauth_release(clnt->cl_auth);
clnt->cl_auth = NULL;
if (atomic_dec_and_test(&clnt->cl_count))
return rpc_free_client(clnt);
return NULL;
}
/*
* Release reference to the RPC client
*/
void
rpc_release_client(struct rpc_clnt *clnt)
{
dprintk("RPC: rpc_release_client(%p)\n", clnt);
do {
if (list_empty(&clnt->cl_tasks))
wake_up(&destroy_wait);
if (!atomic_dec_and_test(&clnt->cl_count))
break;
clnt = rpc_free_auth(clnt);
} while (clnt != NULL);
}
EXPORT_SYMBOL_GPL(rpc_release_client);
/**
* 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,
const struct rpc_program *program,
u32 vers)
{
struct rpc_create_args args = {
.program = program,
.prognumber = program->number,
.version = vers,
.authflavor = old->cl_auth->au_flavor,
};
struct rpc_clnt *clnt;
int err;
clnt = __rpc_clone_client(&args, old);
if (IS_ERR(clnt))
goto out;
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);
void rpc_task_release_client(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
if (clnt != NULL) {
/* Remove from client task list */
spin_lock(&clnt->cl_lock);
list_del(&task->tk_task);
spin_unlock(&clnt->cl_lock);
task->tk_client = NULL;
rpc_release_client(clnt);
}
}
static
void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
{
if (clnt != NULL) {
rpc_task_release_client(task);
task->tk_client = clnt;
atomic_inc(&clnt->cl_count);
if (clnt->cl_softrtry)
task->tk_flags |= RPC_TASK_SOFT;
if (clnt->cl_noretranstimeo)
task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
if (sk_memalloc_socks()) {
struct rpc_xprt *xprt;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
if (xprt->swapper)
task->tk_flags |= RPC_TASK_SWAPPER;
rcu_read_unlock();
}
/* Add to the client's list of all tasks */
spin_lock(&clnt->cl_lock);
list_add_tail(&task->tk_task, &clnt->cl_tasks);
spin_unlock(&clnt->cl_lock);
}
}
void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
{
rpc_task_release_client(task);
rpc_task_set_client(task, clnt);
}
EXPORT_SYMBOL_GPL(rpc_task_reset_client);
static void
rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
{
if (msg != NULL) {
task->tk_msg.rpc_proc = msg->rpc_proc;
task->tk_msg.rpc_argp = msg->rpc_argp;
task->tk_msg.rpc_resp = msg->rpc_resp;
if (msg->rpc_cred != NULL)
task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
}
}
/*
* 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;
rpc_task_set_client(task, task_setup_data->rpc_client);
rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
if (task->tk_action == NULL)
rpc_call_start(task);
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;
WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
if (flags & RPC_TASK_ASYNC) {
rpc_release_calldata(task_setup_data.callback_ops,
task_setup_data.callback_data);
return -EINVAL;
}
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_SUNRPC_BACKCHANNEL)
/**
* 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);
WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
rpc_execute(task);
out:
dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
return task;
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
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;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
bytes = xprt->addrlen;
if (bytes > bufsize)
bytes = bufsize;
memcpy(buf, &xprt->addr, bytes);
rcu_read_unlock();
return bytes;
}
EXPORT_SYMBOL_GPL(rpc_peeraddr);
/**
* rpc_peeraddr2str - return remote peer address in printable format
* @clnt: RPC client structure
* @format: address format
*
* NB: the lifetime of the memory referenced by the returned pointer is
* the same as the rpc_xprt itself. As long as the caller uses this
* pointer, it must hold the RCU read lock.
*/
const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
enum rpc_display_format_t format)
{
struct rpc_xprt *xprt;
xprt = rcu_dereference(clnt->cl_xprt);
if (xprt->address_strings[format] != NULL)
return xprt->address_strings[format];
else
return "unprintable";
}
EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
static const struct sockaddr_in rpc_inaddr_loopback = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_ANY),
};
static const struct sockaddr_in6 rpc_in6addr_loopback = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
};
/*
* Try a getsockname() on a connected datagram socket. Using a
* connected datagram socket prevents leaving a socket in TIME_WAIT.
* This conserves the ephemeral port number space.
*
* Returns zero and fills in "buf" if successful; otherwise, a
* negative errno is returned.
*/
static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
struct sockaddr *buf, int buflen)
{
struct socket *sock;
int err;
err = __sock_create(net, sap->sa_family,
SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
if (err < 0) {
dprintk("RPC: can't create UDP socket (%d)\n", err);
goto out;
}
switch (sap->sa_family) {
case AF_INET:
err = kernel_bind(sock,
(struct sockaddr *)&rpc_inaddr_loopback,
sizeof(rpc_inaddr_loopback));
break;
case AF_INET6:
err = kernel_bind(sock,
(struct sockaddr *)&rpc_in6addr_loopback,
sizeof(rpc_in6addr_loopback));
break;
default:
err = -EAFNOSUPPORT;
goto out;
}
if (err < 0) {
dprintk("RPC: can't bind UDP socket (%d)\n", err);
goto out_release;
}
err = kernel_connect(sock, sap, salen, 0);
if (err < 0) {
dprintk("RPC: can't connect UDP socket (%d)\n", err);
goto out_release;
}
err = kernel_getsockname(sock, buf, &buflen);
if (err < 0) {
dprintk("RPC: getsockname failed (%d)\n", err);
goto out_release;
}
err = 0;
if (buf->sa_family == AF_INET6) {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
sin6->sin6_scope_id = 0;
}
dprintk("RPC: %s succeeded\n", __func__);
out_release:
sock_release(sock);
out:
return err;
}
/*
* Scraping a connected socket failed, so we don't have a useable
* local address. Fallback: generate an address that will prevent
* the server from calling us back.
*
* Returns zero and fills in "buf" if successful; otherwise, a
* negative errno is returned.
*/
static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
{
switch (family) {
case AF_INET:
if (buflen < sizeof(rpc_inaddr_loopback))
return -EINVAL;
memcpy(buf, &rpc_inaddr_loopback,
sizeof(rpc_inaddr_loopback));
break;
case AF_INET6:
if (buflen < sizeof(rpc_in6addr_loopback))
return -EINVAL;
memcpy(buf, &rpc_in6addr_loopback,
sizeof(rpc_in6addr_loopback));
default:
dprintk("RPC: %s: address family not supported\n",
__func__);
return -EAFNOSUPPORT;
}
dprintk("RPC: %s: succeeded\n", __func__);
return 0;
}
/**
* rpc_localaddr - discover local endpoint address for an RPC client
* @clnt: RPC client structure
* @buf: target buffer
* @buflen: size of target buffer, in bytes
*
* Returns zero and fills in "buf" and "buflen" if successful;
* otherwise, a negative errno is returned.
*
* This works even if the underlying transport is not currently connected,
* or if the upper layer never previously provided a source address.
*
* The result of this function call is transient: multiple calls in
* succession may give different results, depending on how local
* networking configuration changes over time.
*/
int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
{
struct sockaddr_storage address;
struct sockaddr *sap = (struct sockaddr *)&address;
struct rpc_xprt *xprt;
struct net *net;
size_t salen;
int err;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
salen = xprt->addrlen;
memcpy(sap, &xprt->addr, salen);
net = get_net(xprt->xprt_net);
rcu_read_unlock();
rpc_set_port(sap, 0);
err = rpc_sockname(net, sap, salen, buf, buflen);
put_net(net);
if (err != 0)
/* Couldn't discover local address, return ANYADDR */
return rpc_anyaddr(sap->sa_family, buf, buflen);
return 0;
}
EXPORT_SYMBOL_GPL(rpc_localaddr);
void
rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
{
struct rpc_xprt *xprt;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
if (xprt->ops->set_buffer_size)
xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rpc_setbufsize);
/**
* rpc_protocol - Get transport protocol number for an RPC client
* @clnt: RPC client to query
*
*/
int rpc_protocol(struct rpc_clnt *clnt)
{
int protocol;
rcu_read_lock();
protocol = rcu_dereference(clnt->cl_xprt)->prot;
rcu_read_unlock();
return protocol;
}
EXPORT_SYMBOL_GPL(rpc_protocol);
/**
* rpc_net_ns - Get the network namespace for this RPC client
* @clnt: RPC client to query
*
*/
struct net *rpc_net_ns(struct rpc_clnt *clnt)
{
struct net *ret;
rcu_read_lock();
ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_net_ns);
/**
* rpc_max_payload - Get maximum payload size for a transport, in bytes
* @clnt: RPC client to query
*
* 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)
{
size_t ret;
rcu_read_lock();
ret = rcu_dereference(clnt->cl_xprt)->max_payload;
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_max_payload);
/**
* rpc_get_timeout - Get timeout for transport in units of HZ
* @clnt: RPC client to query
*/
unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
{
unsigned long ret;
rcu_read_lock();
ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_get_timeout);
/**
* 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) {
rcu_read_lock();
xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
rcu_read_unlock();
}
}
EXPORT_SYMBOL_GPL(rpc_force_rebind);
/*
* Restart an (async) RPC call from the call_prepare state.
* Usually called from within the exit handler.
*/
int
rpc_restart_call_prepare(struct rpc_task *task)
{
if (RPC_ASSASSINATED(task))
return 0;
task->tk_action = call_start;
if (task->tk_ops->rpc_call_prepare != NULL)
task->tk_action = rpc_prepare_task;
return 1;
}
EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
/*
* Restart an (async) RPC call. Usually called from within the
* exit handler.
*/
int
rpc_restart_call(struct rpc_task *task)
{
if (RPC_ASSASSINATED(task))
return 0;
task->tk_action = call_start;
return 1;
}
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_program->name, 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);
task->tk_status = 0;
task->tk_action = call_reserveresult;
xprt_reserve(task);
}
static void call_retry_reserve(struct rpc_task *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_refresh;
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 -ENOMEM:
rpc_delay(task, HZ >> 2);
case -EAGAIN: /* woken up; retry */
task->tk_action = call_retry_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);
}
/*
* 1c. Retry reserving an RPC call slot
*/
static void
call_retry_reserve(struct rpc_task *task)
{
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_reserveresult;
xprt_retry_reserve(task);
}
/*
* 2. Bind and/or refresh the credentials
*/
static void
call_refresh(struct rpc_task *task)
{
dprint_status(task);
task->tk_action = call_refreshresult;
task->tk_status = 0;
task->tk_client->cl_stats->rpcauthrefresh++;
rpcauth_refreshcred(task);
}
/*
* 2a. Process the results of a credential refresh
*/
static void
call_refreshresult(struct rpc_task *task)
{
int status = task->tk_status;
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_refresh;
switch (status) {
case 0:
if (rpcauth_uptodatecred(task))
task->tk_action = call_allocate;
return;
case -ETIMEDOUT:
rpc_delay(task, 3*HZ);
case -EAGAIN:
status = -EACCES;
case -EKEYEXPIRED:
if (!task->tk_cred_retry)
break;
task->tk_cred_retry--;
dprintk("RPC: %5u %s: retry refresh creds\n",
task->tk_pid, __func__);
return;
}
dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
task->tk_pid, __func__, status);
rpc_exit(task, status);
}
/*
* 2b. 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_rqstp->rq_cred->cr_auth->au_cslack;
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_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) || !fatal_signal_pending(current)) {
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;
kxdreproc_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
*/
static void
call_bind(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
dprint_status(task);
task->tk_action = call_connect;
if (!xprt_bound(xprt)) {
task->tk_action = call_bind_status;
task->tk_timeout = xprt->bind_timeout;
xprt->ops->rpcbind(task);
}
}
/*
* 4a. Sort out bind result
*/
static void
call_bind_status(struct rpc_task *task)
{
int status = -EIO;
if (task->tk_status >= 0) {
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_connect;
return;
}
trace_rpc_bind_status(task);
switch (task->tk_status) {
case -ENOMEM:
dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
rpc_delay(task, HZ >> 2);
goto retry_timeout;
case -EACCES:
dprintk("RPC: %5u remote rpcbind: RPC program/version "
"unavailable\n", task->tk_pid);
/* fail immediately if this is an RPC ping */
if (task->tk_msg.rpc_proc->p_proc == 0) {
status = -EOPNOTSUPP;
break;
}
if (task->tk_rebind_retry == 0)
break;
task->tk_rebind_retry--;
rpc_delay(task, 3*HZ);
goto retry_timeout;
case -ETIMEDOUT:
dprintk("RPC: %5u rpcbind request timed out\n",
task->tk_pid);
goto retry_timeout;
case -EPFNOSUPPORT:
/* server doesn't support any rpcbind version we know of */
dprintk("RPC: %5u unrecognized remote rpcbind service\n",
task->tk_pid);
break;
case -EPROTONOSUPPORT:
dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
task->tk_pid);
task->tk_status = 0;
task->tk_action = call_bind;
return;
case -ECONNREFUSED: /* connection problems */
case -ECONNRESET:
case -ENOTCONN:
case -EHOSTDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
case -EPIPE:
dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
task->tk_pid, task->tk_status);
if (!RPC_IS_SOFTCONN(task)) {
rpc_delay(task, 5*HZ);
goto retry_timeout;
}
status = task->tk_status;
break;
default:
dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
task->tk_pid, -task->tk_status);
}
rpc_exit(task, status);
return;
retry_timeout:
task->tk_action = call_timeout;
}
/*
* 4b. Connect to the RPC server
*/
static void
call_connect(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
dprintk("RPC: %5u call_connect xprt %p %s connected\n",
task->tk_pid, xprt,
(xprt_connected(xprt) ? "is" : "is not"));
task->tk_action = call_transmit;
if (!xprt_connected(xprt)) {
task->tk_action = call_connect_status;
if (task->tk_status < 0)
return;
if (task->tk_flags & RPC_TASK_NOCONNECT) {
rpc_exit(task, -ENOTCONN);
return;
}
xprt_connect(task);
}
}
/*
* 4c. Sort out connect result
*/
static void
call_connect_status(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
int status = task->tk_status;
dprint_status(task);
trace_rpc_connect_status(task, status);
task->tk_status = 0;
switch (status) {
/* if soft mounted, test if we've timed out */
case -ETIMEDOUT:
task->tk_action = call_timeout;
return;
case -ECONNREFUSED:
case -ECONNRESET:
case -ENETUNREACH:
/* retry with existing socket, after a delay */
rpc_delay(task, 3*HZ);
if (RPC_IS_SOFTCONN(task))
break;
case -EAGAIN:
task->tk_action = call_bind;
return;
case 0:
clnt->cl_stats->netreconn++;
task->tk_action = call_transmit;
return;
}
rpc_exit(task, status);
}
/*
* 5. Transmit the RPC request, and wait for reply
*/
static void
call_transmit(struct rpc_task *task)
{
int is_retrans = RPC_WAS_SENT(task);
dprint_status(task);
task->tk_action = call_status;
if (task->tk_status < 0)
return;
if (!xprt_prepare_transmit(task))
return;
task->tk_action = call_transmit_status;
/* Encode here so that rpcsec_gss can use correct sequence number. */
if (rpc_task_need_encode(task)) {
rpc_xdr_encode(task);
/* Did the encode result in an error condition? */
if (task->tk_status != 0) {
/* Was the error nonfatal? */
if (task->tk_status == -EAGAIN)
rpc_delay(task, HZ >> 4);
else
rpc_exit(task, task->tk_status);
return;
}
}
xprt_transmit(task);
if (task->tk_status < 0)
return;
if (is_retrans)
task->tk_client->cl_stats->rpcretrans++;
/*
* On success, ensure that we call xprt_end_transmit() before sleeping
* in order to allow access to the socket to other RPC requests.
*/
call_transmit_status(task);
if (rpc_reply_expected(task))
return;
task->tk_action = rpc_exit_task;
rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
}
/*
* 5a. Handle cleanup after a transmission
*/
static void
call_transmit_status(struct rpc_task *task)
{
task->tk_action = call_status;
/*
* Common case: success. Force the compiler to put this
* test first.
*/
if (task->tk_status == 0) {
xprt_end_transmit(task);
rpc_task_force_reencode(task);
return;
}
switch (task->tk_status) {
case -EAGAIN:
break;
default:
dprint_status(task);
xprt_end_transmit(task);
rpc_task_force_reencode(task);
break;
/*
* Special cases: if we've been waiting on the
* socket's write_space() callback, or if the
* socket just returned a connection error,
* then hold onto the transport lock.
*/
case -ECONNREFUSED:
case -EHOSTDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
if (RPC_IS_SOFTCONN(task)) {
xprt_end_transmit(task);
rpc_exit(task, task->tk_status);
break;
}
case -ECONNRESET:
case -ENOTCONN:
case -EPIPE:
rpc_task_force_reencode(task);
}
}
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
/*
* 5b. Send the backchannel RPC reply. On error, drop the reply. In
* addition, disconnect on connectivity errors.
*/
static void
call_bc_transmit(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
if (!xprt_prepare_transmit(task)) {
/*
* Could not reserve the transport. Try again after the
* transport is released.
*/
task->tk_status = 0;
task->tk_action = call_bc_transmit;
return;
}
task->tk_action = rpc_exit_task;
if (task->tk_status < 0) {
printk(KERN_NOTICE "RPC: Could not send backchannel reply "
"error: %d\n", task->tk_status);
return;
}
xprt_transmit(task);
xprt_end_transmit(task);
dprint_status(task);
switch (task->tk_status) {
case 0:
/* Success */
break;
case -EHOSTDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
case -ETIMEDOUT:
/*
* Problem reaching the server. Disconnect and let the
* forechannel reestablish the connection. The server will
* have to retransmit the backchannel request and we'll
* reprocess it. Since these ops are idempotent, there's no
* need to cache our reply at this time.
*/
printk(KERN_NOTICE "RPC: Could not send backchannel reply "
"error: %d\n", task->tk_status);
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
break;
default:
/*
* We were unable to reply and will have to drop the
* request. The server should reconnect and retransmit.
*/
WARN_ON_ONCE(task->tk_status == -EAGAIN);
printk(KERN_NOTICE "RPC: Could not send backchannel reply "
"error: %d\n", task->tk_status);
break;
}
rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
/*
* 6. Sort out the RPC call status
*/
static void
call_status(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
struct rpc_rqst *req = task->tk_rqstp;
int status;
if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
task->tk_status = req->rq_reply_bytes_recvd;
dprint_status(task);
status = task->tk_status;
if (status >= 0) {
task->tk_action = call_decode;
return;
}
trace_rpc_call_status(task);
task->tk_status = 0;
switch(status) {
case -EHOSTDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
/*
* Delay any retries for 3 seconds, then handle as if it
* were a timeout.
*/
rpc_delay(task, 3*HZ);
case -ETIMEDOUT:
task->tk_action = call_timeout;
if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
&& task->tk_client->cl_discrtry)
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
break;
case -ECONNRESET:
case -ECONNREFUSED:
rpc_force_rebind(clnt);
rpc_delay(task, 3*HZ);
case -EPIPE:
case -ENOTCONN:
task->tk_action = call_bind;
break;
case -EAGAIN:
task->tk_action = call_transmit;
break;
case -EIO:
/* shutdown or soft timeout */
rpc_exit(task, status);
break;
default:
if (clnt->cl_chatty)
printk("%s: RPC call returned error %d\n",
clnt->cl_program->name, -status);
rpc_exit(task, status);
}
}
/*
* 6a. Handle RPC timeout
* We do not release the request slot, so we keep using the
* same XID for all retransmits.
*/
static void
call_timeout(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
goto retry;
}
dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
task->tk_timeouts++;
if (RPC_IS_SOFTCONN(task)) {
rpc_exit(task, -ETIMEDOUT);
return;
}
if (RPC_IS_SOFT(task)) {
if (clnt->cl_chatty) {
rcu_read_lock();
printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
clnt->cl_program->name,
rcu_dereference(clnt->cl_xprt)->servername);
rcu_read_unlock();
}
if (task->tk_flags & RPC_TASK_TIMEOUT)
rpc_exit(task, -ETIMEDOUT);
else
rpc_exit(task, -EIO);
return;
}
if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
task->tk_flags |= RPC_CALL_MAJORSEEN;
if (clnt->cl_chatty) {
rcu_read_lock();
printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
clnt->cl_program->name,
rcu_dereference(clnt->cl_xprt)->servername);
rcu_read_unlock();
}
}
rpc_force_rebind(clnt);
/*
* Did our request time out due to an RPCSEC_GSS out-of-sequence
* event? RFC2203 requires the server to drop all such requests.
*/
rpcauth_invalcred(task);
retry:
task->tk_action = call_bind;
task->tk_status = 0;
}
/*
* 7. Decode the RPC reply
*/
static void
call_decode(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
struct rpc_rqst *req = task->tk_rqstp;
kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
__be32 *p;
dprint_status(task);
if (task->tk_flags & RPC_CALL_MAJORSEEN) {
if (clnt->cl_chatty) {
rcu_read_lock();
printk(KERN_NOTICE "%s: server %s OK\n",
clnt->cl_program->name,
rcu_dereference(clnt->cl_xprt)->servername);
rcu_read_unlock();
}
task->tk_flags &= ~RPC_CALL_MAJORSEEN;
}
/*
* Ensure that we see all writes made by xprt_complete_rqst()
* before it changed req->rq_reply_bytes_recvd.
*/
smp_rmb();
req->rq_rcv_buf.len = req->rq_private_buf.len;
/* Check that the softirq receive buffer is valid */
WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
sizeof(req->rq_rcv_buf)) != 0);
if (req->rq_rcv_buf.len < 12) {
if (!RPC_IS_SOFT(task)) {
task->tk_action = call_bind;
goto out_retry;
}
dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
clnt->cl_program->name, task->tk_status);
task->tk_action = call_timeout;
goto out_retry;
}
p = rpc_verify_header(task);
if (IS_ERR(p)) {
if (p == ERR_PTR(-EAGAIN))
goto out_retry;
return;
}
task->tk_action = rpc_exit_task;
if (decode) {
task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
task->tk_msg.rpc_resp);
}
dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
task->tk_status);
return;
out_retry:
task->tk_status = 0;
/* Note: rpc_verify_header() may have freed the RPC slot */
if (task->tk_rqstp == req) {
req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
if (task->tk_client->cl_discrtry)
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
}
}
static __be32 *
rpc_encode_header(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
struct rpc_rqst *req = task->tk_rqstp;
__be32 *p = req->rq_svec[0].iov_base;
/* FIXME: check buffer size? */
p = xprt_skip_transport_header(req->rq_xprt, p);
*p++ = req->rq_xid; /* XID */
*p++ = htonl(RPC_CALL); /* CALL */
*p++ = htonl(RPC_VERSION); /* RPC version */
*p++ = htonl(clnt->cl_prog); /* program number */
*p++ = htonl(clnt->cl_vers); /* program version */
*p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
p = rpcauth_marshcred(task, p);
req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
return p;
}
static __be32 *
rpc_verify_header(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
__be32 *p = iov->iov_base;
u32 n;
int error = -EACCES;
if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
/* RFC-1014 says that the representation of XDR data must be a
* multiple of four bytes
* - if it isn't pointer subtraction in the NFS client may give
* undefined results
*/
dprintk("RPC: %5u %s: XDR representation not a multiple of"
" 4 bytes: 0x%x\n", task->tk_pid, __func__,
task->tk_rqstp->rq_rcv_buf.len);
error = -EIO;
goto out_err;
}
if ((len -= 3) < 0)
goto out_overflow;
p += 1; /* skip XID */
if ((n = ntohl(*p++)) != RPC_REPLY) {
dprintk("RPC: %5u %s: not an RPC reply: %x\n",
task->tk_pid, __func__, n);
error = -EIO;
goto out_garbage;
}
if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
if (--len < 0)
goto out_overflow;
switch ((n = ntohl(*p++))) {
case RPC_AUTH_ERROR:
break;
case RPC_MISMATCH:
dprintk("RPC: %5u %s: RPC call version mismatch!\n",
task->tk_pid, __func__);
error = -EPROTONOSUPPORT;
goto out_err;
default:
dprintk("RPC: %5u %s: RPC call rejected, "
"unknown error: %x\n",
task->tk_pid, __func__, n);
error = -EIO;
goto out_err;
}
if (--len < 0)
goto out_overflow;
switch ((n = ntohl(*p++))) {
case RPC_AUTH_REJECTEDCRED:
case RPC_AUTH_REJECTEDVERF:
case RPCSEC_GSS_CREDPROBLEM:
case RPCSEC_GSS_CTXPROBLEM:
if (!task->tk_cred_retry)
break;
task->tk_cred_retry--;
dprintk("RPC: %5u %s: retry stale creds\n",
task->tk_pid, __func__);
rpcauth_invalcred(task);
/* Ensure we obtain a new XID! */
xprt_release(task);
task->tk_action = call_reserve;
goto out_retry;
case RPC_AUTH_BADCRED:
case RPC_AUTH_BADVERF:
/* possibly garbled cred/verf? */
if (!task->tk_garb_retry)
break;
task->tk_garb_retry--;
dprintk("RPC: %5u %s: retry garbled creds\n",
task->tk_pid, __func__);
task->tk_action = call_bind;
goto out_retry;
case RPC_AUTH_TOOWEAK:
rcu_read_lock();
printk(KERN_NOTICE "RPC: server %s requires stronger "
"authentication.\n",
rcu_dereference(clnt->cl_xprt)->servername);
rcu_read_unlock();
break;
default:
dprintk("RPC: %5u %s: unknown auth error: %x\n",
task->tk_pid, __func__, n);
error = -EIO;
}
dprintk("RPC: %5u %s: call rejected %d\n",
task->tk_pid, __func__, n);
goto out_err;
}
p = rpcauth_checkverf(task, p);
if (IS_ERR(p)) {
error = PTR_ERR(p);
dprintk("RPC: %5u %s: auth check failed with %d\n",
task->tk_pid, __func__, error);
goto out_garbage; /* bad verifier, retry */
}
len = p - (__be32 *)iov->iov_base - 1;
if (len < 0)
goto out_overflow;
switch ((n = ntohl(*p++))) {
case RPC_SUCCESS:
return p;
case RPC_PROG_UNAVAIL:
dprintk_rcu("RPC: %5u %s: program %u is unsupported "
"by server %s\n", task->tk_pid, __func__,
(unsigned int)clnt->cl_prog,
rcu_dereference(clnt->cl_xprt)->servername);
error = -EPFNOSUPPORT;
goto out_err;
case RPC_PROG_MISMATCH:
dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
"by server %s\n", task->tk_pid, __func__,
(unsigned int)clnt->cl_prog,
(unsigned int)clnt->cl_vers,
rcu_dereference(clnt->cl_xprt)->servername);
error = -EPROTONOSUPPORT;
goto out_err;
case RPC_PROC_UNAVAIL:
dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
"version %u on server %s\n",
task->tk_pid, __func__,
rpc_proc_name(task),
clnt->cl_prog, clnt->cl_vers,
rcu_dereference(clnt->cl_xprt)->servername);
error = -EOPNOTSUPP;
goto out_err;
case RPC_GARBAGE_ARGS:
dprintk("RPC: %5u %s: server saw garbage\n",
task->tk_pid, __func__);
break; /* retry */
default:
dprintk("RPC: %5u %s: server accept status: %x\n",
task->tk_pid, __func__, n);
/* Also retry */
}
out_garbage:
clnt->cl_stats->rpcgarbage++;
if (task->tk_garb_retry) {
task->tk_garb_retry--;
dprintk("RPC: %5u %s: retrying\n",
task->tk_pid, __func__);
task->tk_action = call_bind;
out_retry:
return ERR_PTR(-EAGAIN);
}
out_err:
rpc_exit(task, error);
dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
__func__, error);
return ERR_PTR(error);
out_overflow:
dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
__func__);
goto out_garbage;
}
static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
{
}
static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
{
return 0;
}
static struct rpc_procinfo rpcproc_null = {
.p_encode = rpcproc_encode_null,
.p_decode = rpcproc_decode_null,
};
static int rpc_ping(struct rpc_clnt *clnt)
{
struct rpc_message msg = {
.rpc_proc = &rpcproc_null,
};
int err;
msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
put_rpccred(msg.rpc_cred);
return err;
}
struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
{
struct rpc_message msg = {
.rpc_proc = &rpcproc_null,
.rpc_cred = cred,
};
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
.rpc_message = &msg,
.callback_ops = &rpc_default_ops,
.flags = flags,
};
return rpc_run_task(&task_setup_data);
}
EXPORT_SYMBOL_GPL(rpc_call_null);
#ifdef RPC_DEBUG
static void rpc_show_header(void)
{
printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
"-timeout ---ops--\n");
}
static void rpc_show_task(const struct rpc_clnt *clnt,
const struct rpc_task *task)
{
const char *rpc_waitq = "none";
if (RPC_IS_QUEUED(task))
rpc_waitq = rpc_qname(task->tk_waitqueue);
printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
task->tk_pid, task->tk_flags, task->tk_status,
clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
task->tk_action, rpc_waitq);
}
void rpc_show_tasks(struct net *net)
{
struct rpc_clnt *clnt;
struct rpc_task *task;
int header = 0;
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
spin_lock(&sn->rpc_client_lock);
list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
spin_lock(&clnt->cl_lock);
list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
if (!header) {
rpc_show_header();
header++;
}
rpc_show_task(clnt, task);
}
spin_unlock(&clnt->cl_lock);
}
spin_unlock(&sn->rpc_client_lock);
}
#endif
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