linux/net/sunrpc/clnt.c
NeilBrown 7c4310ff56 SUNRPC: defer slow parts of rpc_free_client() to a workqueue.
The rpciod workqueue is on the write-out path for freeing dirty memory,
so it is important that it never block waiting for memory to be
allocated - this can lead to a deadlock.

rpc_execute() - which is often called by an rpciod work item - calls
rcp_task_release_client() which can lead to rpc_free_client().

rpc_free_client() makes two calls which could potentially block wating
for memory allocation.

rpc_clnt_debugfs_unregister() calls into debugfs and will block while
any of the debugfs files are being accessed.  In particular it can block
while any of the 'open' methods are being called and all of these use
malloc for one thing or another.  So this can deadlock if the memory
allocation waits for NFS to complete some writes via rpciod.

rpc_clnt_remove_pipedir() can take the inode_lock() and while it isn't
obvious that memory allocations can happen while the lock it held, it is
safer to assume they might and to not let rpciod call
rpc_clnt_remove_pipedir().

So this patch moves these two calls (together with the final kfree() and
rpciod_down()) into a work-item to be run from the system work-queue.
rpciod can continue its important work, and the final stages of the free
can happen whenever they happen.

I have seen this deadlock on a 4.12 based kernel where debugfs used
synchronize_srcu() when removing objects.  synchronize_srcu() requires a
workqueue and there were no free workther threads and none could be
allocated.  While debugsfs no longer uses SRCU, I believe the deadlock
is still possible.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-04-28 15:58:38 -04:00

3111 lines
73 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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"
#if IS_ENABLED(CONFIG_SUNRPC_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_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_connect(struct rpc_task *task);
static void call_connect_status(struct rpc_task *task);
static int rpc_encode_header(struct rpc_task *task,
struct xdr_stream *xdr);
static int rpc_decode_header(struct rpc_task *task,
struct xdr_stream *xdr);
static int rpc_ping(struct rpc_clnt *clnt);
static void rpc_check_timeout(struct rpc_task *task);
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;
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 0;
}
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 = strlcpy(clnt->cl_nodename,
nodename, sizeof(clnt->cl_nodename));
}
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;
rpc_clnt_debugfs_register(clnt);
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);
rpc_clnt_debugfs_unregister(clnt);
return err;
}
static DEFINE_IDA(rpc_clids);
void rpc_cleanup_clids(void)
{
ida_destroy(&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_switch *xps,
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;
const char *nodename = args->nodename;
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_cred = get_cred(args->cred);
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);
xprt_iter_init(&clnt->cl_xpi, xps);
xprt_switch_put(xps);
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);
if (nodename == NULL)
nodename = utsname()->nodename;
/* save the nodename */
rpc_clnt_set_nodename(clnt, 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:
put_cred(clnt->cl_cred);
rpc_free_clid(clnt);
out_no_clid:
kfree(clnt);
out_err:
rpciod_down();
out_no_rpciod:
xprt_switch_put(xps);
xprt_put(xprt);
return ERR_PTR(err);
}
static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
struct rpc_xprt *xprt)
{
struct rpc_clnt *clnt = NULL;
struct rpc_xprt_switch *xps;
if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
xps = args->bc_xprt->xpt_bc_xps;
xprt_switch_get(xps);
} else {
xps = xprt_switch_alloc(xprt, GFP_KERNEL);
if (xps == NULL) {
xprt_put(xprt);
return ERR_PTR(-ENOMEM);
}
if (xprt->bc_xprt) {
xprt_switch_get(xps);
xprt->bc_xprt->xpt_bc_xps = xps;
}
}
clnt = rpc_new_client(args, xps, 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|RPC_CLNT_CREATE_SOFTERR)) {
clnt->cl_softrtry = 0;
if (args->flags & RPC_CLNT_CREATE_SOFTERR)
clnt->cl_softerr = 1;
}
if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
clnt->cl_autobind = 1;
if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
clnt->cl_noretranstimeo = 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;
}
/**
* 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 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];
struct rpc_clnt *clnt;
int i;
if (args->bc_xprt) {
WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
xprt = args->bc_xprt->xpt_bc_xprt;
if (xprt) {
xprt_get(xprt);
return rpc_create_xprt(args, xprt);
}
}
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;
xprt->reuseport = 0;
if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
xprt->reuseport = 1;
clnt = rpc_create_xprt(args, xprt);
if (IS_ERR(clnt) || args->nconnect <= 1)
return clnt;
for (i = 0; i < args->nconnect - 1; i++) {
if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
break;
}
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_switch *xps;
struct rpc_xprt *xprt;
struct rpc_clnt *new;
int err;
err = -ENOMEM;
rcu_read_lock();
xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
rcu_read_unlock();
if (xprt == NULL || xps == NULL) {
xprt_put(xprt);
xprt_switch_put(xps);
goto out_err;
}
args->servername = xprt->servername;
args->nodename = clnt->cl_nodename;
new = rpc_new_client(args, xps, 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_softerr = clnt->cl_softerr;
new->cl_noretranstimeo = clnt->cl_noretranstimeo;
new->cl_discrtry = clnt->cl_discrtry;
new->cl_chatty = clnt->cl_chatty;
new->cl_principal = clnt->cl_principal;
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,
.cred = clnt->cl_cred,
};
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,
.cred = clnt->cl_cred,
};
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_switch *xps, *oldxps;
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);
}
xps = xprt_switch_alloc(xprt, GFP_KERNEL);
if (xps == NULL) {
xprt_put(xprt);
return -ENOMEM;
}
pseudoflavor = clnt->cl_auth->au_flavor;
old_timeo = clnt->cl_timeout;
old = rpc_clnt_set_transport(clnt, xprt, timeout);
oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
rpc_unregister_client(clnt);
__rpc_clnt_remove_pipedir(clnt);
rpc_clnt_debugfs_unregister(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_switch_put(oldxps);
xprt_put(old);
dprintk("RPC: replaced xprt for clnt %p\n", clnt);
return 0;
out_revert:
xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
rpc_clnt_set_transport(clnt, old, old_timeo);
clnt->cl_parent = parent;
rpc_client_register(clnt, pseudoflavor, NULL);
xprt_switch_put(xps);
xprt_put(xprt);
dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
return err;
}
EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
static
int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
{
struct rpc_xprt_switch *xps;
rcu_read_lock();
xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
rcu_read_unlock();
if (xps == NULL)
return -EAGAIN;
xprt_iter_init_listall(xpi, xps);
xprt_switch_put(xps);
return 0;
}
/**
* rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
* @clnt: pointer to client
* @fn: function to apply
* @data: void pointer to function data
*
* Iterates through the list of RPC transports currently attached to the
* client and applies the function fn(clnt, xprt, data).
*
* On error, the iteration stops, and the function returns the error value.
*/
int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
void *data)
{
struct rpc_xprt_iter xpi;
int ret;
ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
if (ret)
return ret;
for (;;) {
struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
if (!xprt)
break;
ret = fn(clnt, xprt, data);
xprt_put(xprt);
if (ret < 0)
break;
}
xprt_iter_destroy(&xpi);
return ret;
}
EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
/*
* 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)
rpc_signal_task(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 void rpc_free_client_work(struct work_struct *work)
{
struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
/* These might block on processes that might allocate memory,
* so they cannot be called in rpciod, so they are handled separately
* here.
*/
rpc_clnt_debugfs_unregister(clnt);
rpc_clnt_remove_pipedir(clnt);
kfree(clnt);
rpciod_down();
}
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_unregister_client(clnt);
rpc_free_iostats(clnt->cl_metrics);
clnt->cl_metrics = NULL;
xprt_put(rcu_dereference_raw(clnt->cl_xprt));
xprt_iter_destroy(&clnt->cl_xpi);
put_cred(clnt->cl_cred);
rpc_free_clid(clnt);
INIT_WORK(&clnt->cl_work, rpc_free_client_work);
schedule_work(&clnt->cl_work);
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,
.cred = old->cl_cred,
};
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);
struct rpc_xprt *
rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
{
struct rpc_xprt_switch *xps;
if (!xprt)
return NULL;
rcu_read_lock();
xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
atomic_long_inc(&xps->xps_queuelen);
rcu_read_unlock();
atomic_long_inc(&xprt->queuelen);
return xprt;
}
static void
rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
{
struct rpc_xprt_switch *xps;
atomic_long_dec(&xprt->queuelen);
rcu_read_lock();
xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
atomic_long_dec(&xps->xps_queuelen);
rcu_read_unlock();
xprt_put(xprt);
}
void rpc_task_release_transport(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_xprt;
if (xprt) {
task->tk_xprt = NULL;
if (task->tk_client)
rpc_task_release_xprt(task->tk_client, xprt);
else
xprt_put(xprt);
}
}
EXPORT_SYMBOL_GPL(rpc_task_release_transport);
void rpc_task_release_client(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
rpc_task_release_transport(task);
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 struct rpc_xprt *
rpc_task_get_first_xprt(struct rpc_clnt *clnt)
{
struct rpc_xprt *xprt;
rcu_read_lock();
xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
rcu_read_unlock();
return rpc_task_get_xprt(clnt, xprt);
}
static struct rpc_xprt *
rpc_task_get_next_xprt(struct rpc_clnt *clnt)
{
return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
}
static
void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
{
if (task->tk_xprt)
return;
if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
task->tk_xprt = rpc_task_get_first_xprt(clnt);
else
task->tk_xprt = rpc_task_get_next_xprt(clnt);
}
static
void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
{
if (clnt != NULL) {
rpc_task_set_transport(task, clnt);
task->tk_client = clnt;
atomic_inc(&clnt->cl_count);
if (clnt->cl_softrtry)
task->tk_flags |= RPC_TASK_SOFT;
if (clnt->cl_softerr)
task->tk_flags |= RPC_TASK_TIMEOUT;
if (clnt->cl_noretranstimeo)
task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
if (atomic_read(&clnt->cl_swapper))
task->tk_flags |= RPC_TASK_SWAPPER;
/* 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);
}
}
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;
task->tk_msg.rpc_cred = msg->rpc_cred;
if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
get_cred(task->tk_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 (!RPC_IS_ASYNC(task))
task->tk_flags |= RPC_TASK_CRED_NOREF;
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);
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)
static void call_bc_encode(struct rpc_task *task);
/**
* rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
* rpc_execute against it
* @req: RPC request
*/
struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
{
struct rpc_task *task;
struct rpc_task_setup task_setup_data = {
.callback_ops = &rpc_default_ops,
.flags = RPC_TASK_SOFTCONN |
RPC_TASK_NO_RETRANS_TIMEOUT,
};
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);
xprt_init_bc_request(req, task);
task->tk_action = call_bc_encode;
atomic_inc(&task->tk_count);
WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
rpc_execute(task);
dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
return task;
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
/**
* rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
* @req: RPC request to prepare
* @pages: vector of struct page pointers
* @base: offset in first page where receive should start, in bytes
* @len: expected size of the upper layer data payload, in bytes
* @hdrsize: expected size of upper layer reply header, in XDR words
*
*/
void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
unsigned int base, unsigned int len,
unsigned int hdrsize)
{
/* Subtract one to force an extra word of buffer space for the
* payload's XDR pad to fall into the rcv_buf's tail iovec.
*/
hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
trace_rpc_reply_pages(req);
}
EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
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)
{
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);
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));
break;
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);
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_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_max_bc_payload - Get maximum backchannel payload size, in bytes
* @clnt: RPC client to query
*/
size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
{
struct rpc_xprt *xprt;
size_t ret;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
ret = xprt->ops->bc_maxpayload(xprt);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
{
struct rpc_xprt *xprt;
unsigned int ret;
rcu_read_lock();
xprt = rcu_dereference(clnt->cl_xprt);
ret = xprt->ops->bc_num_slots(xprt);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
/**
* 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);
static int
__rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
{
task->tk_status = 0;
task->tk_rpc_status = 0;
task->tk_action = action;
return 1;
}
/*
* Restart an (async) RPC call. Usually called from within the
* exit handler.
*/
int
rpc_restart_call(struct rpc_task *task)
{
return __rpc_restart_call(task, call_start);
}
EXPORT_SYMBOL_GPL(rpc_restart_call);
/*
* 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 (task->tk_ops->rpc_call_prepare != NULL)
return __rpc_restart_call(task, rpc_prepare_task);
return rpc_restart_call(task);
}
EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
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";
}
static void
__rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
{
task->tk_rpc_status = rpc_status;
rpc_exit(task, tk_status);
}
static void
rpc_call_rpcerror(struct rpc_task *task, int status)
{
__rpc_call_rpcerror(task, status, status);
}
/*
* 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;
int idx = task->tk_msg.rpc_proc->p_statidx;
trace_rpc_request(task);
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 (version might not be valid for ping) */
if (clnt->cl_program->version[clnt->cl_vers])
clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
clnt->cl_stats->rpccnt++;
task->tk_action = call_reserve;
rpc_task_set_transport(task, clnt);
}
/*
* 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;
}
rpc_call_rpcerror(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)
xprt_release(task);
switch (status) {
case -ENOMEM:
rpc_delay(task, HZ >> 2);
/* fall through */
case -EAGAIN: /* woken up; retry */
task->tk_action = call_retry_reserve;
return;
default:
rpc_call_rpcerror(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;
}
/* Use rate-limiting and a max number of retries if refresh
* had status 0 but failed to update the cred.
*/
/* fall through */
case -ETIMEDOUT:
rpc_delay(task, 3*HZ);
/* fall through */
case -EAGAIN:
status = -EACCES;
/* fall through */
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_call_rpcerror(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)
{
const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
int status;
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_encode;
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 + (auth->au_cslack << 1) +
proc->p_arglen;
req->rq_callsize <<= 2;
/*
* Note: the reply buffer must at minimum allocate enough space
* for the 'struct accepted_reply' from RFC5531.
*/
req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
max_t(size_t, proc->p_replen, 2);
req->rq_rcvsize <<= 2;
status = xprt->ops->buf_alloc(task);
xprt_inject_disconnect(xprt);
if (status == 0)
return;
if (status != -ENOMEM) {
rpc_call_rpcerror(task, status);
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_call_rpcerror(task, -ERESTARTSYS);
}
static int
rpc_task_need_encode(struct rpc_task *task)
{
return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
(!(task->tk_flags & RPC_TASK_SENT) ||
!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
xprt_request_need_retransmit(task));
}
static void
rpc_xdr_encode(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
struct xdr_stream xdr;
xdr_buf_init(&req->rq_snd_buf,
req->rq_buffer,
req->rq_callsize);
xdr_buf_init(&req->rq_rcv_buf,
req->rq_rbuffer,
req->rq_rcvsize);
req->rq_reply_bytes_recvd = 0;
req->rq_snd_buf.head[0].iov_len = 0;
xdr_init_encode(&xdr, &req->rq_snd_buf,
req->rq_snd_buf.head[0].iov_base, req);
xdr_free_bvec(&req->rq_snd_buf);
if (rpc_encode_header(task, &xdr))
return;
task->tk_status = rpcauth_wrap_req(task, &xdr);
}
/*
* 3. Encode arguments of an RPC call
*/
static void
call_encode(struct rpc_task *task)
{
if (!rpc_task_need_encode(task))
goto out;
dprint_status(task);
/* Dequeue task from the receive queue while we're encoding */
xprt_request_dequeue_xprt(task);
/* Encode here so that rpcsec_gss can use correct sequence number. */
rpc_xdr_encode(task);
/* Did the encode result in an error condition? */
if (task->tk_status != 0) {
/* Was the error nonfatal? */
switch (task->tk_status) {
case -EAGAIN:
case -ENOMEM:
rpc_delay(task, HZ >> 4);
break;
case -EKEYEXPIRED:
if (!task->tk_cred_retry) {
rpc_exit(task, task->tk_status);
} else {
task->tk_action = call_refresh;
task->tk_cred_retry--;
dprintk("RPC: %5u %s: retry refresh creds\n",
task->tk_pid, __func__);
}
break;
default:
rpc_call_rpcerror(task, task->tk_status);
}
return;
}
/* Add task to reply queue before transmission to avoid races */
if (rpc_reply_expected(task))
xprt_request_enqueue_receive(task);
xprt_request_enqueue_transmit(task);
out:
task->tk_action = call_transmit;
/* Check that the connection is OK */
if (!xprt_bound(task->tk_xprt))
task->tk_action = call_bind;
else if (!xprt_connected(task->tk_xprt))
task->tk_action = call_connect;
}
/*
* Helpers to check if the task was already transmitted, and
* to take action when that is the case.
*/
static bool
rpc_task_transmitted(struct rpc_task *task)
{
return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
}
static void
rpc_task_handle_transmitted(struct rpc_task *task)
{
xprt_end_transmit(task);
task->tk_action = call_transmit_status;
}
/*
* 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;
if (rpc_task_transmitted(task)) {
rpc_task_handle_transmitted(task);
return;
}
if (xprt_bound(xprt)) {
task->tk_action = call_connect;
return;
}
dprint_status(task);
task->tk_action = call_bind_status;
if (!xprt_prepare_transmit(task))
return;
xprt->ops->rpcbind(task);
}
/*
* 4a. Sort out bind result
*/
static void
call_bind_status(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
int status = -EIO;
if (rpc_task_transmitted(task)) {
rpc_task_handle_transmitted(task);
return;
}
dprint_status(task);
trace_rpc_bind_status(task);
if (task->tk_status >= 0)
goto out_next;
if (xprt_bound(xprt)) {
task->tk_status = 0;
goto out_next;
}
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 -ENOBUFS:
rpc_delay(task, HZ >> 2);
goto retry_timeout;
case -EAGAIN:
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);
goto retry_timeout;
case -ECONNREFUSED: /* connection problems */
case -ECONNRESET:
case -ECONNABORTED:
case -ENOTCONN:
case -EHOSTDOWN:
case -ENETDOWN:
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_call_rpcerror(task, status);
return;
out_next:
task->tk_action = call_connect;
return;
retry_timeout:
task->tk_status = 0;
task->tk_action = call_bind;
rpc_check_timeout(task);
}
/*
* 4b. Connect to the RPC server
*/
static void
call_connect(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
if (rpc_task_transmitted(task)) {
rpc_task_handle_transmitted(task);
return;
}
if (xprt_connected(xprt)) {
task->tk_action = call_transmit;
return;
}
dprintk("RPC: %5u call_connect xprt %p %s connected\n",
task->tk_pid, xprt,
(xprt_connected(xprt) ? "is" : "is not"));
task->tk_action = call_connect_status;
if (task->tk_status < 0)
return;
if (task->tk_flags & RPC_TASK_NOCONNECT) {
rpc_call_rpcerror(task, -ENOTCONN);
return;
}
if (!xprt_prepare_transmit(task))
return;
xprt_connect(task);
}
/*
* 4c. Sort out connect result
*/
static void
call_connect_status(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
struct rpc_clnt *clnt = task->tk_client;
int status = task->tk_status;
if (rpc_task_transmitted(task)) {
rpc_task_handle_transmitted(task);
return;
}
dprint_status(task);
trace_rpc_connect_status(task);
if (task->tk_status == 0) {
clnt->cl_stats->netreconn++;
goto out_next;
}
if (xprt_connected(xprt)) {
task->tk_status = 0;
goto out_next;
}
task->tk_status = 0;
switch (status) {
case -ECONNREFUSED:
/* A positive refusal suggests a rebind is needed. */
if (RPC_IS_SOFTCONN(task))
break;
if (clnt->cl_autobind) {
rpc_force_rebind(clnt);
goto out_retry;
}
/* fall through */
case -ECONNRESET:
case -ECONNABORTED:
case -ENETDOWN:
case -ENETUNREACH:
case -EHOSTUNREACH:
case -EPIPE:
case -EPROTO:
xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
task->tk_rqstp->rq_connect_cookie);
if (RPC_IS_SOFTCONN(task))
break;
/* retry with existing socket, after a delay */
rpc_delay(task, 3*HZ);
/* fall through */
case -EADDRINUSE:
case -ENOTCONN:
case -EAGAIN:
case -ETIMEDOUT:
goto out_retry;
case -ENOBUFS:
rpc_delay(task, HZ >> 2);
goto out_retry;
}
rpc_call_rpcerror(task, status);
return;
out_next:
task->tk_action = call_transmit;
return;
out_retry:
/* Check for timeouts before looping back to call_bind */
task->tk_action = call_bind;
rpc_check_timeout(task);
}
/*
* 5. Transmit the RPC request, and wait for reply
*/
static void
call_transmit(struct rpc_task *task)
{
if (rpc_task_transmitted(task)) {
rpc_task_handle_transmitted(task);
return;
}
dprint_status(task);
task->tk_action = call_transmit_status;
if (!xprt_prepare_transmit(task))
return;
task->tk_status = 0;
if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
if (!xprt_connected(task->tk_xprt)) {
task->tk_status = -ENOTCONN;
return;
}
xprt_transmit(task);
}
xprt_end_transmit(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 (rpc_task_transmitted(task)) {
task->tk_status = 0;
xprt_request_wait_receive(task);
return;
}
switch (task->tk_status) {
default:
dprint_status(task);
break;
case -EBADMSG:
task->tk_status = 0;
task->tk_action = call_encode;
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 -ENOBUFS:
rpc_delay(task, HZ>>2);
/* fall through */
case -EBADSLT:
case -EAGAIN:
task->tk_action = call_transmit;
task->tk_status = 0;
break;
case -ECONNREFUSED:
case -EHOSTDOWN:
case -ENETDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
case -EPERM:
if (RPC_IS_SOFTCONN(task)) {
if (!task->tk_msg.rpc_proc->p_proc)
trace_xprt_ping(task->tk_xprt,
task->tk_status);
rpc_call_rpcerror(task, task->tk_status);
return;
}
/* fall through */
case -ECONNRESET:
case -ECONNABORTED:
case -EADDRINUSE:
case -ENOTCONN:
case -EPIPE:
task->tk_action = call_bind;
task->tk_status = 0;
break;
}
rpc_check_timeout(task);
}
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
static void call_bc_transmit(struct rpc_task *task);
static void call_bc_transmit_status(struct rpc_task *task);
static void
call_bc_encode(struct rpc_task *task)
{
xprt_request_enqueue_transmit(task);
task->tk_action = call_bc_transmit;
}
/*
* 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)
{
task->tk_action = call_bc_transmit_status;
if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
if (!xprt_prepare_transmit(task))
return;
task->tk_status = 0;
xprt_transmit(task);
}
xprt_end_transmit(task);
}
static void
call_bc_transmit_status(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
if (rpc_task_transmitted(task))
task->tk_status = 0;
dprint_status(task);
switch (task->tk_status) {
case 0:
/* Success */
case -ENETDOWN:
case -EHOSTDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
case -ECONNRESET:
case -ECONNREFUSED:
case -EADDRINUSE:
case -ENOTCONN:
case -EPIPE:
break;
case -ENOBUFS:
rpc_delay(task, HZ>>2);
/* fall through */
case -EBADSLT:
case -EAGAIN:
task->tk_status = 0;
task->tk_action = call_bc_transmit;
return;
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.
*/
printk(KERN_NOTICE "RPC: Could not send backchannel reply "
"error: %d\n", task->tk_status);
break;
}
task->tk_action = rpc_exit_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;
int status;
if (!task->tk_msg.rpc_proc->p_proc)
trace_xprt_ping(task->tk_xprt, task->tk_status);
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 -ENETDOWN:
case -EHOSTUNREACH:
case -ENETUNREACH:
case -EPERM:
if (RPC_IS_SOFTCONN(task))
goto out_exit;
/*
* Delay any retries for 3 seconds, then handle as if it
* were a timeout.
*/
rpc_delay(task, 3*HZ);
/* fall through */
case -ETIMEDOUT:
break;
case -ECONNREFUSED:
case -ECONNRESET:
case -ECONNABORTED:
case -ENOTCONN:
rpc_force_rebind(clnt);
break;
case -EADDRINUSE:
rpc_delay(task, 3*HZ);
/* fall through */
case -EPIPE:
case -EAGAIN:
break;
case -EIO:
/* shutdown or soft timeout */
goto out_exit;
default:
if (clnt->cl_chatty)
printk("%s: RPC call returned error %d\n",
clnt->cl_program->name, -status);
goto out_exit;
}
task->tk_action = call_encode;
rpc_check_timeout(task);
return;
out_exit:
rpc_call_rpcerror(task, status);
}
static bool
rpc_check_connected(const struct rpc_rqst *req)
{
/* No allocated request or transport? return true */
if (!req || !req->rq_xprt)
return true;
return xprt_connected(req->rq_xprt);
}
static void
rpc_check_timeout(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
if (xprt_adjust_timeout(task->tk_rqstp) == 0)
return;
dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
task->tk_timeouts++;
if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
rpc_call_rpcerror(task, -ETIMEDOUT);
return;
}
if (RPC_IS_SOFT(task)) {
/*
* Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
* been sent, it should time out only if the transport
* connection gets terminally broken.
*/
if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
rpc_check_connected(task->tk_rqstp))
return;
if (clnt->cl_chatty) {
pr_notice_ratelimited(
"%s: server %s not responding, timed out\n",
clnt->cl_program->name,
task->tk_xprt->servername);
}
if (task->tk_flags & RPC_TASK_TIMEOUT)
rpc_call_rpcerror(task, -ETIMEDOUT);
else
__rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
return;
}
if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
task->tk_flags |= RPC_CALL_MAJORSEEN;
if (clnt->cl_chatty) {
pr_notice_ratelimited(
"%s: server %s not responding, still trying\n",
clnt->cl_program->name,
task->tk_xprt->servername);
}
}
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);
}
/*
* 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;
struct xdr_stream xdr;
int err;
dprint_status(task);
if (!task->tk_msg.rpc_proc->p_decode) {
task->tk_action = rpc_exit_task;
return;
}
if (task->tk_flags & RPC_CALL_MAJORSEEN) {
if (clnt->cl_chatty) {
pr_notice_ratelimited("%s: server %s OK\n",
clnt->cl_program->name,
task->tk_xprt->servername);
}
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();
/*
* Did we ever call xprt_complete_rqst()? If not, we should assume
* the message is incomplete.
*/
err = -EAGAIN;
if (!req->rq_reply_bytes_recvd)
goto out;
req->rq_rcv_buf.len = req->rq_private_buf.len;
trace_xprt_recvfrom(&req->rq_rcv_buf);
/* 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);
xdr_init_decode(&xdr, &req->rq_rcv_buf,
req->rq_rcv_buf.head[0].iov_base, req);
err = rpc_decode_header(task, &xdr);
out:
switch (err) {
case 0:
task->tk_action = rpc_exit_task;
task->tk_status = rpcauth_unwrap_resp(task, &xdr);
dprintk("RPC: %5u %s result %d\n",
task->tk_pid, __func__, task->tk_status);
return;
case -EAGAIN:
task->tk_status = 0;
if (task->tk_client->cl_discrtry)
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
task->tk_action = call_encode;
rpc_check_timeout(task);
break;
case -EKEYREJECTED:
task->tk_action = call_reserve;
rpc_check_timeout(task);
rpcauth_invalcred(task);
/* Ensure we obtain a new XID if we retry! */
xprt_release(task);
}
}
static int
rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
{
struct rpc_clnt *clnt = task->tk_client;
struct rpc_rqst *req = task->tk_rqstp;
__be32 *p;
int error;
error = -EMSGSIZE;
p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
if (!p)
goto out_fail;
*p++ = req->rq_xid;
*p++ = rpc_call;
*p++ = cpu_to_be32(RPC_VERSION);
*p++ = cpu_to_be32(clnt->cl_prog);
*p++ = cpu_to_be32(clnt->cl_vers);
*p = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
error = rpcauth_marshcred(task, xdr);
if (error < 0)
goto out_fail;
return 0;
out_fail:
trace_rpc_bad_callhdr(task);
rpc_call_rpcerror(task, error);
return error;
}
static noinline int
rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
{
struct rpc_clnt *clnt = task->tk_client;
int error;
__be32 *p;
/* 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
*/
if (task->tk_rqstp->rq_rcv_buf.len & 3)
goto out_unparsable;
p = xdr_inline_decode(xdr, 3 * sizeof(*p));
if (!p)
goto out_unparsable;
p++; /* skip XID */
if (*p++ != rpc_reply)
goto out_unparsable;
if (*p++ != rpc_msg_accepted)
goto out_msg_denied;
error = rpcauth_checkverf(task, xdr);
if (error)
goto out_verifier;
p = xdr_inline_decode(xdr, sizeof(*p));
if (!p)
goto out_unparsable;
switch (*p) {
case rpc_success:
return 0;
case rpc_prog_unavail:
trace_rpc__prog_unavail(task);
error = -EPFNOSUPPORT;
goto out_err;
case rpc_prog_mismatch:
trace_rpc__prog_mismatch(task);
error = -EPROTONOSUPPORT;
goto out_err;
case rpc_proc_unavail:
trace_rpc__proc_unavail(task);
error = -EOPNOTSUPP;
goto out_err;
case rpc_garbage_args:
case rpc_system_err:
trace_rpc__garbage_args(task);
error = -EIO;
break;
default:
goto out_unparsable;
}
out_garbage:
clnt->cl_stats->rpcgarbage++;
if (task->tk_garb_retry) {
task->tk_garb_retry--;
task->tk_action = call_encode;
return -EAGAIN;
}
out_err:
rpc_call_rpcerror(task, error);
return error;
out_unparsable:
trace_rpc__unparsable(task);
error = -EIO;
goto out_garbage;
out_verifier:
trace_rpc_bad_verifier(task);
goto out_garbage;
out_msg_denied:
error = -EACCES;
p = xdr_inline_decode(xdr, sizeof(*p));
if (!p)
goto out_unparsable;
switch (*p++) {
case rpc_auth_error:
break;
case rpc_mismatch:
trace_rpc__mismatch(task);
error = -EPROTONOSUPPORT;
goto out_err;
default:
goto out_unparsable;
}
p = xdr_inline_decode(xdr, sizeof(*p));
if (!p)
goto out_unparsable;
switch (*p++) {
case rpc_autherr_rejectedcred:
case rpc_autherr_rejectedverf:
case rpcsec_gsserr_credproblem:
case rpcsec_gsserr_ctxproblem:
if (!task->tk_cred_retry)
break;
task->tk_cred_retry--;
trace_rpc__stale_creds(task);
return -EKEYREJECTED;
case rpc_autherr_badcred:
case rpc_autherr_badverf:
/* possibly garbled cred/verf? */
if (!task->tk_garb_retry)
break;
task->tk_garb_retry--;
trace_rpc__bad_creds(task);
task->tk_action = call_encode;
return -EAGAIN;
case rpc_autherr_tooweak:
trace_rpc__auth_tooweak(task);
pr_warn("RPC: server %s requires stronger authentication.\n",
task->tk_xprt->servername);
break;
default:
goto out_unparsable;
}
goto out_err;
}
static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
const void *obj)
{
}
static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
void *obj)
{
return 0;
}
static const 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;
err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
RPC_TASK_NULLCREDS);
return err;
}
static
struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
const struct rpc_call_ops *ops, void *data)
{
struct rpc_message msg = {
.rpc_proc = &rpcproc_null,
};
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
.rpc_xprt = xprt,
.rpc_message = &msg,
.rpc_op_cred = cred,
.callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
.callback_data = data,
.flags = flags | RPC_TASK_NULLCREDS,
};
return rpc_run_task(&task_setup_data);
}
struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
{
return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
}
EXPORT_SYMBOL_GPL(rpc_call_null);
struct rpc_cb_add_xprt_calldata {
struct rpc_xprt_switch *xps;
struct rpc_xprt *xprt;
};
static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
{
struct rpc_cb_add_xprt_calldata *data = calldata;
if (task->tk_status == 0)
rpc_xprt_switch_add_xprt(data->xps, data->xprt);
}
static void rpc_cb_add_xprt_release(void *calldata)
{
struct rpc_cb_add_xprt_calldata *data = calldata;
xprt_put(data->xprt);
xprt_switch_put(data->xps);
kfree(data);
}
static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
.rpc_call_done = rpc_cb_add_xprt_done,
.rpc_release = rpc_cb_add_xprt_release,
};
/**
* rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
* @clnt: pointer to struct rpc_clnt
* @xps: pointer to struct rpc_xprt_switch,
* @xprt: pointer struct rpc_xprt
* @dummy: unused
*/
int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
void *dummy)
{
struct rpc_cb_add_xprt_calldata *data;
struct rpc_task *task;
data = kmalloc(sizeof(*data), GFP_NOFS);
if (!data)
return -ENOMEM;
data->xps = xprt_switch_get(xps);
data->xprt = xprt_get(xprt);
if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
rpc_cb_add_xprt_release(data);
goto success;
}
task = rpc_call_null_helper(clnt, xprt, NULL,
RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
&rpc_cb_add_xprt_call_ops, data);
rpc_put_task(task);
success:
return 1;
}
EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
/**
* rpc_clnt_setup_test_and_add_xprt()
*
* This is an rpc_clnt_add_xprt setup() function which returns 1 so:
* 1) caller of the test function must dereference the rpc_xprt_switch
* and the rpc_xprt.
* 2) test function must call rpc_xprt_switch_add_xprt, usually in
* the rpc_call_done routine.
*
* Upon success (return of 1), the test function adds the new
* transport to the rpc_clnt xprt switch
*
* @clnt: struct rpc_clnt to get the new transport
* @xps: the rpc_xprt_switch to hold the new transport
* @xprt: the rpc_xprt to test
* @data: a struct rpc_add_xprt_test pointer that holds the test function
* and test function call data
*/
int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
struct rpc_xprt_switch *xps,
struct rpc_xprt *xprt,
void *data)
{
struct rpc_task *task;
struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
int status = -EADDRINUSE;
xprt = xprt_get(xprt);
xprt_switch_get(xps);
if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
goto out_err;
/* Test the connection */
task = rpc_call_null_helper(clnt, xprt, NULL,
RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
NULL, NULL);
if (IS_ERR(task)) {
status = PTR_ERR(task);
goto out_err;
}
status = task->tk_status;
rpc_put_task(task);
if (status < 0)
goto out_err;
/* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
xtest->add_xprt_test(clnt, xprt, xtest->data);
xprt_put(xprt);
xprt_switch_put(xps);
/* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
return 1;
out_err:
xprt_put(xprt);
xprt_switch_put(xps);
pr_info("RPC: rpc_clnt_test_xprt failed: %d addr %s not added\n",
status, xprt->address_strings[RPC_DISPLAY_ADDR]);
return status;
}
EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
/**
* rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
* @clnt: pointer to struct rpc_clnt
* @xprtargs: pointer to struct xprt_create
* @setup: callback to test and/or set up the connection
* @data: pointer to setup function data
*
* Creates a new transport using the parameters set in args and
* adds it to clnt.
* If ping is set, then test that connectivity succeeds before
* adding the new transport.
*
*/
int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
struct xprt_create *xprtargs,
int (*setup)(struct rpc_clnt *,
struct rpc_xprt_switch *,
struct rpc_xprt *,
void *),
void *data)
{
struct rpc_xprt_switch *xps;
struct rpc_xprt *xprt;
unsigned long connect_timeout;
unsigned long reconnect_timeout;
unsigned char resvport, reuseport;
int ret = 0;
rcu_read_lock();
xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
xprt = xprt_iter_xprt(&clnt->cl_xpi);
if (xps == NULL || xprt == NULL) {
rcu_read_unlock();
xprt_switch_put(xps);
return -EAGAIN;
}
resvport = xprt->resvport;
reuseport = xprt->reuseport;
connect_timeout = xprt->connect_timeout;
reconnect_timeout = xprt->max_reconnect_timeout;
rcu_read_unlock();
xprt = xprt_create_transport(xprtargs);
if (IS_ERR(xprt)) {
ret = PTR_ERR(xprt);
goto out_put_switch;
}
xprt->resvport = resvport;
xprt->reuseport = reuseport;
if (xprt->ops->set_connect_timeout != NULL)
xprt->ops->set_connect_timeout(xprt,
connect_timeout,
reconnect_timeout);
rpc_xprt_switch_set_roundrobin(xps);
if (setup) {
ret = setup(clnt, xps, xprt, data);
if (ret != 0)
goto out_put_xprt;
}
rpc_xprt_switch_add_xprt(xps, xprt);
out_put_xprt:
xprt_put(xprt);
out_put_switch:
xprt_switch_put(xps);
return ret;
}
EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
struct connect_timeout_data {
unsigned long connect_timeout;
unsigned long reconnect_timeout;
};
static int
rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
struct rpc_xprt *xprt,
void *data)
{
struct connect_timeout_data *timeo = data;
if (xprt->ops->set_connect_timeout)
xprt->ops->set_connect_timeout(xprt,
timeo->connect_timeout,
timeo->reconnect_timeout);
return 0;
}
void
rpc_set_connect_timeout(struct rpc_clnt *clnt,
unsigned long connect_timeout,
unsigned long reconnect_timeout)
{
struct connect_timeout_data timeout = {
.connect_timeout = connect_timeout,
.reconnect_timeout = reconnect_timeout,
};
rpc_clnt_iterate_for_each_xprt(clnt,
rpc_xprt_set_connect_timeout,
&timeout);
}
EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
{
rcu_read_lock();
xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
{
rcu_read_lock();
rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
xprt);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
const struct sockaddr *sap)
{
struct rpc_xprt_switch *xps;
bool ret;
rcu_read_lock();
xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
ret = rpc_xprt_switch_has_addr(xps, sap);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
#if IS_ENABLED(CONFIG_SUNRPC_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, rpc_task_timeout(task), 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
#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
static int
rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
struct rpc_xprt *xprt,
void *dummy)
{
return xprt_enable_swap(xprt);
}
int
rpc_clnt_swap_activate(struct rpc_clnt *clnt)
{
if (atomic_inc_return(&clnt->cl_swapper) == 1)
return rpc_clnt_iterate_for_each_xprt(clnt,
rpc_clnt_swap_activate_callback, NULL);
return 0;
}
EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
static int
rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
struct rpc_xprt *xprt,
void *dummy)
{
xprt_disable_swap(xprt);
return 0;
}
void
rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
{
if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
rpc_clnt_iterate_for_each_xprt(clnt,
rpc_clnt_swap_deactivate_callback, NULL);
}
EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
#endif /* CONFIG_SUNRPC_SWAP */