Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 1583 insertions, 0 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
new file mode 100644
index 0000000..4895c34
--- /dev/null
+++ b/net/sunrpc/clnt.c
@@ -0,0 +1,1583 @@
+/*
+ *  linux/net/sunrpc/clnt.c
+ *
+ *  This file contains the high-level RPC interface.
+ *  It is modeled as a finite state machine to support both synchronous
+ *  and asynchronous requests.
+ *
+ *  -	RPC header generation and argument serialization.
+ *  -	Credential refresh.
+ *  -	TCP connect handling.
+ *  -	Retry of operation when it is suspected the operation failed because
+ *	of uid squashing on the server, or when the credentials were stale
+ *	and need to be refreshed, or when a packet was damaged in transit.
+ *	This may be have to be moved to the VFS layer.
+ *
+ *  NB: BSD uses a more intelligent approach to guessing when a request
+ *  or reply has been lost by keeping the RTO estimate for each procedure.
+ *  We currently make do with a constant timeout value.
+ *
+ *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
+ *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <asm/system.h>
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kallsyms.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/utsname.h>
+#include <linux/workqueue.h>
+#include <linux/in6.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/metrics.h>
+
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY	RPCDBG_CALL
+#endif
+
+#define dprint_status(t)					\
+	dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,		\
+			__func__, t->tk_status)
+
+/*
+ * All RPC clients are linked into this list
+ */
+static LIST_HEAD(all_clients);
+static DEFINE_SPINLOCK(rpc_client_lock);
+
+static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
+
+
+static void	call_start(struct rpc_task *task);
+static void	call_reserve(struct rpc_task *task);
+static void	call_reserveresult(struct rpc_task *task);
+static void	call_allocate(struct rpc_task *task);
+static void	call_decode(struct rpc_task *task);
+static void	call_bind(struct rpc_task *task);
+static void	call_bind_status(struct rpc_task *task);
+static void	call_transmit(struct rpc_task *task);
+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, int flags);
+
+static void rpc_register_client(struct rpc_clnt *clnt)
+{
+	spin_lock(&rpc_client_lock);
+	list_add(&clnt->cl_clients, &all_clients);
+	spin_unlock(&rpc_client_lock);
+}
+
+static void rpc_unregister_client(struct rpc_clnt *clnt)
+{
+	spin_lock(&rpc_client_lock);
+	list_del(&clnt->cl_clients);
+	spin_unlock(&rpc_client_lock);
+}
+
+static int
+rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
+{
+	static uint32_t clntid;
+	int error;
+
+	clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
+	clnt->cl_dentry = ERR_PTR(-ENOENT);
+	if (dir_name == NULL)
+		return 0;
+
+	clnt->cl_vfsmnt = rpc_get_mount();
+	if (IS_ERR(clnt->cl_vfsmnt))
+		return PTR_ERR(clnt->cl_vfsmnt);
+
+	for (;;) {
+		snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
+				"%s/clnt%x", dir_name,
+				(unsigned int)clntid++);
+		clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
+		clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
+		if (!IS_ERR(clnt->cl_dentry))
+			return 0;
+		error = PTR_ERR(clnt->cl_dentry);
+		if (error != -EEXIST) {
+			printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
+					clnt->cl_pathname, error);
+			rpc_put_mount();
+			return error;
+		}
+	}
+}
+
+static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
+{
+	struct rpc_program	*program = args->program;
+	struct rpc_version	*version;
+	struct rpc_clnt		*clnt = NULL;
+	struct rpc_auth		*auth;
+	int err;
+	size_t len;
+
+	/* sanity check the name before trying to print it */
+	err = -EINVAL;
+	len = strlen(args->servername);
+	if (len > RPC_MAXNETNAMELEN)
+		goto out_no_rpciod;
+	len++;
+
+	dprintk("RPC:       creating %s client for %s (xprt %p)\n",
+			program->name, args->servername, xprt);
+
+	err = rpciod_up();
+	if (err)
+		goto out_no_rpciod;
+	err = -EINVAL;
+	if (!xprt)
+		goto out_no_xprt;
+
+	if (args->version >= program->nrvers)
+		goto out_err;
+	version = program->version[args->version];
+	if (version == NULL)
+		goto out_err;
+
+	err = -ENOMEM;
+	clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
+	if (!clnt)
+		goto out_err;
+	clnt->cl_parent = clnt;
+
+	clnt->cl_server = clnt->cl_inline_name;
+	if (len > sizeof(clnt->cl_inline_name)) {
+		char *buf = kmalloc(len, GFP_KERNEL);
+		if (buf != NULL)
+			clnt->cl_server = buf;
+		else
+			len = sizeof(clnt->cl_inline_name);
+	}
+	strlcpy(clnt->cl_server, args->servername, len);
+
+	clnt->cl_xprt     = xprt;
+	clnt->cl_procinfo = version->procs;
+	clnt->cl_maxproc  = version->nrprocs;
+	clnt->cl_protname = program->name;
+	clnt->cl_prog     = args->prognumber ? : program->number;
+	clnt->cl_vers     = version->number;
+	clnt->cl_stats    = program->stats;
+	clnt->cl_metrics  = rpc_alloc_iostats(clnt);
+	err = -ENOMEM;
+	if (clnt->cl_metrics == NULL)
+		goto out_no_stats;
+	clnt->cl_program  = program;
+	INIT_LIST_HEAD(&clnt->cl_tasks);
+	spin_lock_init(&clnt->cl_lock);
+
+	if (!xprt_bound(clnt->cl_xprt))
+		clnt->cl_autobind = 1;
+
+	clnt->cl_timeout = xprt->timeout;
+	if (args->timeout != NULL) {
+		memcpy(&clnt->cl_timeout_default, args->timeout,
+				sizeof(clnt->cl_timeout_default));
+		clnt->cl_timeout = &clnt->cl_timeout_default;
+	}
+
+	clnt->cl_rtt = &clnt->cl_rtt_default;
+	rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
+
+	kref_init(&clnt->cl_kref);
+
+	err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
+	if (err < 0)
+		goto out_no_path;
+
+	auth = rpcauth_create(args->authflavor, clnt);
+	if (IS_ERR(auth)) {
+		printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
+				args->authflavor);
+		err = PTR_ERR(auth);
+		goto out_no_auth;
+	}
+
+	/* save the nodename */
+	clnt->cl_nodelen = strlen(init_utsname()->nodename);
+	if (clnt->cl_nodelen > UNX_MAXNODENAME)
+		clnt->cl_nodelen = UNX_MAXNODENAME;
+	memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
+	rpc_register_client(clnt);
+	return clnt;
+
+out_no_auth:
+	if (!IS_ERR(clnt->cl_dentry)) {
+		rpc_rmdir(clnt->cl_dentry);
+		rpc_put_mount();
+	}
+out_no_path:
+	rpc_free_iostats(clnt->cl_metrics);
+out_no_stats:
+	if (clnt->cl_server != clnt->cl_inline_name)
+		kfree(clnt->cl_server);
+	kfree(clnt);
+out_err:
+	xprt_put(xprt);
+out_no_xprt:
+	rpciod_down();
+out_no_rpciod:
+	return ERR_PTR(err);
+}
+
+/*
+ * rpc_create - create an RPC client and transport with one call
+ * @args: rpc_clnt create argument structure
+ *
+ * Creates and initializes an RPC transport and an RPC client.
+ *
+ * It can ping the server in order to determine if it is up, and to see if
+ * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
+ * this behavior so asynchronous tasks can also use rpc_create.
+ */
+struct rpc_clnt *rpc_create(struct rpc_create_args *args)
+{
+	struct rpc_xprt *xprt;
+	struct rpc_clnt *clnt;
+	struct xprt_create xprtargs = {
+		.ident = args->protocol,
+		.srcaddr = args->saddress,
+		.dstaddr = args->address,
+		.addrlen = args->addrsize,
+	};
+	char servername[48];
+
+	/*
+	 * If the caller chooses not to specify a hostname, whip
+	 * up a string representation of the passed-in address.
+	 */
+	if (args->servername == NULL) {
+		servername[0] = '\0';
+		switch (args->address->sa_family) {
+		case AF_INET: {
+			struct sockaddr_in *sin =
+					(struct sockaddr_in *)args->address;
+			snprintf(servername, sizeof(servername), NIPQUAD_FMT,
+				 NIPQUAD(sin->sin_addr.s_addr));
+			break;
+		}
+		case AF_INET6: {
+			struct sockaddr_in6 *sin =
+					(struct sockaddr_in6 *)args->address;
+			snprintf(servername, sizeof(servername), NIP6_FMT,
+				 NIP6(sin->sin6_addr));
+			break;
+		}
+		default:
+			/* caller wants default server name, but
+			 * address family isn't recognized. */
+			return ERR_PTR(-EINVAL);
+		}
+		args->servername = servername;
+	}
+
+	xprt = xprt_create_transport(&xprtargs);
+	if (IS_ERR(xprt))
+		return (struct rpc_clnt *)xprt;
+
+	/*
+	 * By default, kernel RPC client connects from a reserved port.
+	 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
+	 * but it is always enabled for rpciod, which handles the connect
+	 * operation.
+	 */
+	xprt->resvport = 1;
+	if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
+		xprt->resvport = 0;
+
+	clnt = rpc_new_client(args, xprt);
+	if (IS_ERR(clnt))
+		return clnt;
+
+	if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
+		int err = rpc_ping(clnt, RPC_TASK_SOFT);
+		if (err != 0) {
+			rpc_shutdown_client(clnt);
+			return ERR_PTR(err);
+		}
+	}
+
+	clnt->cl_softrtry = 1;
+	if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
+		clnt->cl_softrtry = 0;
+
+	if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
+		clnt->cl_autobind = 1;
+	if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
+		clnt->cl_discrtry = 1;
+	if (!(args->flags & RPC_CLNT_CREATE_QUIET))
+		clnt->cl_chatty = 1;
+
+	return clnt;
+}
+EXPORT_SYMBOL_GPL(rpc_create);
+
+/*
+ * This function clones the RPC client structure. It allows us to share the
+ * same transport while varying parameters such as the authentication
+ * flavour.
+ */
+struct rpc_clnt *
+rpc_clone_client(struct rpc_clnt *clnt)
+{
+	struct rpc_clnt *new;
+	int err = -ENOMEM;
+
+	new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto out_no_clnt;
+	new->cl_parent = clnt;
+	/* Turn off autobind on clones */
+	new->cl_autobind = 0;
+	INIT_LIST_HEAD(&new->cl_tasks);
+	spin_lock_init(&new->cl_lock);
+	rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
+	new->cl_metrics = rpc_alloc_iostats(clnt);
+	if (new->cl_metrics == NULL)
+		goto out_no_stats;
+	kref_init(&new->cl_kref);
+	err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
+	if (err != 0)
+		goto out_no_path;
+	if (new->cl_auth)
+		atomic_inc(&new->cl_auth->au_count);
+	xprt_get(clnt->cl_xprt);
+	kref_get(&clnt->cl_kref);
+	rpc_register_client(new);
+	rpciod_up();
+	return new;
+out_no_path:
+	rpc_free_iostats(new->cl_metrics);
+out_no_stats:
+	kfree(new);
+out_no_clnt:
+	dprintk("RPC:       %s: returned error %d\n", __func__, err);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(rpc_clone_client);
+
+/*
+ * Properly shut down an RPC client, terminating all outstanding
+ * requests.
+ */
+void rpc_shutdown_client(struct rpc_clnt *clnt)
+{
+	dprintk("RPC:       shutting down %s client for %s\n",
+			clnt->cl_protname, clnt->cl_server);
+
+	while (!list_empty(&clnt->cl_tasks)) {
+		rpc_killall_tasks(clnt);
+		wait_event_timeout(destroy_wait,
+			list_empty(&clnt->cl_tasks), 1*HZ);
+	}
+
+	rpc_release_client(clnt);
+}
+EXPORT_SYMBOL_GPL(rpc_shutdown_client);
+
+/*
+ * Free an RPC client
+ */
+static void
+rpc_free_client(struct kref *kref)
+{
+	struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
+
+	dprintk("RPC:       destroying %s client for %s\n",
+			clnt->cl_protname, clnt->cl_server);
+	if (!IS_ERR(clnt->cl_dentry)) {
+		rpc_rmdir(clnt->cl_dentry);
+		rpc_put_mount();
+	}
+	if (clnt->cl_parent != clnt) {
+		rpc_release_client(clnt->cl_parent);
+		goto out_free;
+	}
+	if (clnt->cl_server != clnt->cl_inline_name)
+		kfree(clnt->cl_server);
+out_free:
+	rpc_unregister_client(clnt);
+	rpc_free_iostats(clnt->cl_metrics);
+	clnt->cl_metrics = NULL;
+	xprt_put(clnt->cl_xprt);
+	rpciod_down();
+	kfree(clnt);
+}
+
+/*
+ * Free an RPC client
+ */
+static void
+rpc_free_auth(struct kref *kref)
+{
+	struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
+
+	if (clnt->cl_auth == NULL) {
+		rpc_free_client(kref);
+		return;
+	}
+
+	/*
+	 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
+	 *       release remaining GSS contexts. This mechanism ensures
+	 *       that it can do so safely.
+	 */
+	kref_init(kref);
+	rpcauth_release(clnt->cl_auth);
+	clnt->cl_auth = NULL;
+	kref_put(kref, rpc_free_client);
+}
+
+/*
+ * Release reference to the RPC client
+ */
+void
+rpc_release_client(struct rpc_clnt *clnt)
+{
+	dprintk("RPC:       rpc_release_client(%p)\n", clnt);
+
+	if (list_empty(&clnt->cl_tasks))
+		wake_up(&destroy_wait);
+	kref_put(&clnt->cl_kref, rpc_free_auth);
+}
+
+/**
+ * rpc_bind_new_program - bind a new RPC program to an existing client
+ * @old: old rpc_client
+ * @program: rpc program to set
+ * @vers: rpc program version
+ *
+ * Clones the rpc client and sets up a new RPC program. This is mainly
+ * of use for enabling different RPC programs to share the same transport.
+ * The Sun NFSv2/v3 ACL protocol can do this.
+ */
+struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
+				      struct rpc_program *program,
+				      u32 vers)
+{
+	struct rpc_clnt *clnt;
+	struct rpc_version *version;
+	int err;
+
+	BUG_ON(vers >= program->nrvers || !program->version[vers]);
+	version = program->version[vers];
+	clnt = rpc_clone_client(old);
+	if (IS_ERR(clnt))
+		goto out;
+	clnt->cl_procinfo = version->procs;
+	clnt->cl_maxproc  = version->nrprocs;
+	clnt->cl_protname = program->name;
+	clnt->cl_prog     = program->number;
+	clnt->cl_vers     = version->number;
+	clnt->cl_stats    = program->stats;
+	err = rpc_ping(clnt, RPC_TASK_SOFT);
+	if (err != 0) {
+		rpc_shutdown_client(clnt);
+		clnt = ERR_PTR(err);
+	}
+out:
+	return clnt;
+}
+EXPORT_SYMBOL_GPL(rpc_bind_new_program);
+
+/*
+ * Default callback for async RPC calls
+ */
+static void
+rpc_default_callback(struct rpc_task *task, void *data)
+{
+}
+
+static const struct rpc_call_ops rpc_default_ops = {
+	.rpc_call_done = rpc_default_callback,
+};
+
+/**
+ * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
+ * @task_setup_data: pointer to task initialisation data
+ */
+struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
+{
+	struct rpc_task *task, *ret;
+
+	task = rpc_new_task(task_setup_data);
+	if (task == NULL) {
+		rpc_release_calldata(task_setup_data->callback_ops,
+				task_setup_data->callback_data);
+		ret = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	if (task->tk_status != 0) {
+		ret = ERR_PTR(task->tk_status);
+		rpc_put_task(task);
+		goto out;
+	}
+	atomic_inc(&task->tk_count);
+	rpc_execute(task);
+	ret = task;
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_run_task);
+
+/**
+ * rpc_call_sync - Perform a synchronous RPC call
+ * @clnt: pointer to RPC client
+ * @msg: RPC call parameters
+ * @flags: RPC call flags
+ */
+int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
+{
+	struct rpc_task	*task;
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clnt,
+		.rpc_message = msg,
+		.callback_ops = &rpc_default_ops,
+		.flags = flags,
+	};
+	int status;
+
+	BUG_ON(flags & RPC_TASK_ASYNC);
+
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	status = task->tk_status;
+	rpc_put_task(task);
+	return status;
+}
+EXPORT_SYMBOL_GPL(rpc_call_sync);
+
+/**
+ * rpc_call_async - Perform an asynchronous RPC call
+ * @clnt: pointer to RPC client
+ * @msg: RPC call parameters
+ * @flags: RPC call flags
+ * @tk_ops: RPC call ops
+ * @data: user call data
+ */
+int
+rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
+	       const struct rpc_call_ops *tk_ops, void *data)
+{
+	struct rpc_task	*task;
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clnt,
+		.rpc_message = msg,
+		.callback_ops = tk_ops,
+		.callback_data = data,
+		.flags = flags|RPC_TASK_ASYNC,
+	};
+
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rpc_call_async);
+
+void
+rpc_call_start(struct rpc_task *task)
+{
+	task->tk_action = call_start;
+}
+EXPORT_SYMBOL_GPL(rpc_call_start);
+
+/**
+ * rpc_peeraddr - extract remote peer address from clnt's xprt
+ * @clnt: RPC client structure
+ * @buf: target buffer
+ * @bufsize: length of target buffer
+ *
+ * Returns the number of bytes that are actually in the stored address.
+ */
+size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
+{
+	size_t bytes;
+	struct rpc_xprt *xprt = clnt->cl_xprt;
+
+	bytes = sizeof(xprt->addr);
+	if (bytes > bufsize)
+		bytes = bufsize;
+	memcpy(buf, &clnt->cl_xprt->addr, bytes);
+	return xprt->addrlen;
+}
+EXPORT_SYMBOL_GPL(rpc_peeraddr);
+
+/**
+ * rpc_peeraddr2str - return remote peer address in printable format
+ * @clnt: RPC client structure
+ * @format: address format
+ *
+ */
+const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
+			     enum rpc_display_format_t format)
+{
+	struct rpc_xprt *xprt = clnt->cl_xprt;
+
+	if (xprt->address_strings[format] != NULL)
+		return xprt->address_strings[format];
+	else
+		return "unprintable";
+}
+EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
+
+void
+rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
+{
+	struct rpc_xprt *xprt = clnt->cl_xprt;
+	if (xprt->ops->set_buffer_size)
+		xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
+}
+EXPORT_SYMBOL_GPL(rpc_setbufsize);
+
+/*
+ * Return size of largest payload RPC client can support, in bytes
+ *
+ * For stream transports, this is one RPC record fragment (see RFC
+ * 1831), as we don't support multi-record requests yet.  For datagram
+ * transports, this is the size of an IP packet minus the IP, UDP, and
+ * RPC header sizes.
+ */
+size_t rpc_max_payload(struct rpc_clnt *clnt)
+{
+	return clnt->cl_xprt->max_payload;
+}
+EXPORT_SYMBOL_GPL(rpc_max_payload);
+
+/**
+ * rpc_force_rebind - force transport to check that remote port is unchanged
+ * @clnt: client to rebind
+ *
+ */
+void rpc_force_rebind(struct rpc_clnt *clnt)
+{
+	if (clnt->cl_autobind)
+		xprt_clear_bound(clnt->cl_xprt);
+}
+EXPORT_SYMBOL_GPL(rpc_force_rebind);
+
+/*
+ * Restart an (async) RPC call. Usually called from within the
+ * exit handler.
+ */
+void
+rpc_restart_call(struct rpc_task *task)
+{
+	if (RPC_ASSASSINATED(task))
+		return;
+
+	task->tk_action = call_start;
+}
+EXPORT_SYMBOL_GPL(rpc_restart_call);
+
+#ifdef RPC_DEBUG
+static const char *rpc_proc_name(const struct rpc_task *task)
+{
+	const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
+
+	if (proc) {
+		if (proc->p_name)
+			return proc->p_name;
+		else
+			return "NULL";
+	} else
+		return "no proc";
+}
+#endif
+
+/*
+ * 0.  Initial state
+ *
+ *     Other FSM states can be visited zero or more times, but
+ *     this state is visited exactly once for each RPC.
+ */
+static void
+call_start(struct rpc_task *task)
+{
+	struct rpc_clnt	*clnt = task->tk_client;
+
+	dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
+			clnt->cl_protname, clnt->cl_vers,
+			rpc_proc_name(task),
+			(RPC_IS_ASYNC(task) ? "async" : "sync"));
+
+	/* Increment call count */
+	task->tk_msg.rpc_proc->p_count++;
+	clnt->cl_stats->rpccnt++;
+	task->tk_action = call_reserve;
+}
+
+/*
+ * 1.	Reserve an RPC call slot
+ */
+static void
+call_reserve(struct rpc_task *task)
+{
+	dprint_status(task);
+
+	if (!rpcauth_uptodatecred(task)) {
+		task->tk_action = call_refresh;
+		return;
+	}
+
+	task->tk_status  = 0;
+	task->tk_action  = call_reserveresult;
+	xprt_reserve(task);
+}
+
+/*
+ * 1b.	Grok the result of xprt_reserve()
+ */
+static void
+call_reserveresult(struct rpc_task *task)
+{
+	int status = task->tk_status;
+
+	dprint_status(task);
+
+	/*
+	 * After a call to xprt_reserve(), we must have either
+	 * a request slot or else an error status.
+	 */
+	task->tk_status = 0;
+	if (status >= 0) {
+		if (task->tk_rqstp) {
+			task->tk_action = call_allocate;
+			return;
+		}
+
+		printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
+				__func__, status);
+		rpc_exit(task, -EIO);
+		return;
+	}
+
+	/*
+	 * Even though there was an error, we may have acquired
+	 * a request slot somehow.  Make sure not to leak it.
+	 */
+	if (task->tk_rqstp) {
+		printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
+				__func__, status);
+		xprt_release(task);
+	}
+
+	switch (status) {
+	case -EAGAIN:	/* woken up; retry */
+		task->tk_action = call_reserve;
+		return;
+	case -EIO:	/* probably a shutdown */
+		break;
+	default:
+		printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
+				__func__, status);
+		break;
+	}
+	rpc_exit(task, status);
+}
+
+/*
+ * 2.	Allocate the buffer. For details, see sched.c:rpc_malloc.
+ *	(Note: buffer memory is freed in xprt_release).
+ */
+static void
+call_allocate(struct rpc_task *task)
+{
+	unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
+	struct rpc_rqst *req = task->tk_rqstp;
+	struct rpc_xprt *xprt = task->tk_xprt;
+	struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
+
+	dprint_status(task);
+
+	task->tk_status = 0;
+	task->tk_action = call_bind;
+
+	if (req->rq_buffer)
+		return;
+
+	if (proc->p_proc != 0) {
+		BUG_ON(proc->p_arglen == 0);
+		if (proc->p_decode != NULL)
+			BUG_ON(proc->p_replen == 0);
+	}
+
+	/*
+	 * Calculate the size (in quads) of the RPC call
+	 * and reply headers, and convert both values
+	 * to byte sizes.
+	 */
+	req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
+	req->rq_callsize <<= 2;
+	req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
+	req->rq_rcvsize <<= 2;
+
+	req->rq_buffer = xprt->ops->buf_alloc(task,
+					req->rq_callsize + req->rq_rcvsize);
+	if (req->rq_buffer != NULL)
+		return;
+
+	dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
+
+	if (RPC_IS_ASYNC(task) || !signalled()) {
+		task->tk_action = call_allocate;
+		rpc_delay(task, HZ>>4);
+		return;
+	}
+
+	rpc_exit(task, -ERESTARTSYS);
+}
+
+static inline int
+rpc_task_need_encode(struct rpc_task *task)
+{
+	return task->tk_rqstp->rq_snd_buf.len == 0;
+}
+
+static inline void
+rpc_task_force_reencode(struct rpc_task *task)
+{
+	task->tk_rqstp->rq_snd_buf.len = 0;
+}
+
+static inline void
+rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
+{
+	buf->head[0].iov_base = start;
+	buf->head[0].iov_len = len;
+	buf->tail[0].iov_len = 0;
+	buf->page_len = 0;
+	buf->flags = 0;
+	buf->len = 0;
+	buf->buflen = len;
+}
+
+/*
+ * 3.	Encode arguments of an RPC call
+ */
+static void
+rpc_xdr_encode(struct rpc_task *task)
+{
+	struct rpc_rqst	*req = task->tk_rqstp;
+	kxdrproc_t	encode;
+	__be32		*p;
+
+	dprint_status(task);
+
+	rpc_xdr_buf_init(&req->rq_snd_buf,
+			 req->rq_buffer,
+			 req->rq_callsize);
+	rpc_xdr_buf_init(&req->rq_rcv_buf,
+			 (char *)req->rq_buffer + req->rq_callsize,
+			 req->rq_rcvsize);
+
+	p = rpc_encode_header(task);
+	if (p == NULL) {
+		printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
+		rpc_exit(task, -EIO);
+		return;
+	}
+
+	encode = task->tk_msg.rpc_proc->p_encode;
+	if (encode == NULL)
+		return;
+
+	task->tk_status = rpcauth_wrap_req(task, encode, req, p,
+			task->tk_msg.rpc_argp);
+}
+
+/*
+ * 4.	Get the server port number if not yet set
+ */
+static void
+call_bind(struct rpc_task *task)
+{
+	struct rpc_xprt *xprt = task->tk_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;
+	}
+
+	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;
+		}
+		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 remote rpcbind service unavailable\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;
+	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_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;
+		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);
+
+	task->tk_status = 0;
+	if (status >= 0) {
+		clnt->cl_stats->netreconn++;
+		task->tk_action = call_transmit;
+		return;
+	}
+
+	/* Something failed: remote service port may have changed */
+	rpc_force_rebind(clnt);
+
+	switch (status) {
+	case -ENOTCONN:
+	case -EAGAIN:
+		task->tk_action = call_bind;
+		if (!RPC_IS_SOFT(task))
+			return;
+		/* if soft mounted, test if we've timed out */
+	case -ETIMEDOUT:
+		task->tk_action = call_timeout;
+		return;
+	}
+	rpc_exit(task, -EIO);
+}
+
+/*
+ * 5.	Transmit the RPC request, and wait for reply
+ */
+static void
+call_transmit(struct rpc_task *task)
+{
+	dprint_status(task);
+
+	task->tk_action = call_status;
+	if (task->tk_status < 0)
+		return;
+	task->tk_status = xprt_prepare_transmit(task);
+	if (task->tk_status != 0)
+		return;
+	task->tk_action = call_transmit_status;
+	/* Encode here so that rpcsec_gss can use correct sequence number. */
+	if (rpc_task_need_encode(task)) {
+		BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
+		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;
+	/*
+	 * 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 (task->tk_msg.rpc_proc->p_decode != NULL)
+		return;
+	task->tk_action = rpc_exit_task;
+	rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
+}
+
+/*
+ * 5a.	Handle cleanup after a transmission
+ */
+static void
+call_transmit_status(struct rpc_task *task)
+{
+	task->tk_action = call_status;
+	/*
+	 * Special case: if we've been waiting on the socket's write_space()
+	 * callback, then don't call xprt_end_transmit().
+	 */
+	if (task->tk_status == -EAGAIN)
+		return;
+	xprt_end_transmit(task);
+	rpc_task_force_reencode(task);
+}
+
+/*
+ * 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_received > 0 && !req->rq_bytes_sent)
+		task->tk_status = req->rq_received;
+
+	dprint_status(task);
+
+	status = task->tk_status;
+	if (status >= 0) {
+		task->tk_action = call_decode;
+		return;
+	}
+
+	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_client->cl_discrtry)
+			xprt_conditional_disconnect(task->tk_xprt,
+					req->rq_connect_cookie);
+		break;
+	case -ECONNREFUSED:
+	case -ENOTCONN:
+		rpc_force_rebind(clnt);
+		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_protname, -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_SOFT(task)) {
+		if (clnt->cl_chatty)
+			printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
+				clnt->cl_protname, clnt->cl_server);
+		rpc_exit(task, -EIO);
+		return;
+	}
+
+	if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
+		task->tk_flags |= RPC_CALL_MAJORSEEN;
+		if (clnt->cl_chatty)
+			printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
+			clnt->cl_protname, clnt->cl_server);
+	}
+	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:
+	clnt->cl_stats->rpcretrans++;
+	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;
+	kxdrproc_t	decode = task->tk_msg.rpc_proc->p_decode;
+	__be32		*p;
+
+	dprintk("RPC: %5u call_decode (status %d)\n",
+			task->tk_pid, task->tk_status);
+
+	if (task->tk_flags & RPC_CALL_MAJORSEEN) {
+		if (clnt->cl_chatty)
+			printk(KERN_NOTICE "%s: server %s OK\n",
+				clnt->cl_protname, clnt->cl_server);
+		task->tk_flags &= ~RPC_CALL_MAJORSEEN;
+	}
+
+	/*
+	 * Ensure that we see all writes made by xprt_complete_rqst()
+	 * before it changed req->rq_received.
+	 */
+	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;
+			clnt->cl_stats->rpcretrans++;
+			goto out_retry;
+		}
+		dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
+				clnt->cl_protname, 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_received = req->rq_rcv_buf.len = 0;
+		if (task->tk_client->cl_discrtry)
+			xprt_conditional_disconnect(task->tk_xprt,
+					req->rq_connect_cookie);
+	}
+}
+
+/*
+ * 8.	Refresh the credentials if rejected by the server
+ */
+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);
+}
+
+/*
+ * 8a.	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_reserve;
+	if (status >= 0 && rpcauth_uptodatecred(task))
+		return;
+	if (status == -EACCES) {
+		rpc_exit(task, -EACCES);
+		return;
+	}
+	task->tk_action = call_refresh;
+	if (status != -ETIMEDOUT)
+		rpc_delay(task, 3*HZ);
+	return;
+}
+
+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(task->tk_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 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);
+		goto out_eio;
+	}
+	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);
+		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);
+				goto out_eio;
+		}
+		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_refresh;
+			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:
+			printk(KERN_NOTICE "RPC: server %s requires stronger "
+			       "authentication.\n", task->tk_client->cl_server);
+			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;
+	}
+	if (!(p = rpcauth_checkverf(task, p))) {
+		dprintk("RPC: %5u %s: auth check failed\n",
+				task->tk_pid, __func__);
+		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("RPC: %5u %s: program %u is unsupported by server %s\n",
+				task->tk_pid, __func__,
+				(unsigned int)task->tk_client->cl_prog,
+				task->tk_client->cl_server);
+		error = -EPFNOSUPPORT;
+		goto out_err;
+	case RPC_PROG_MISMATCH:
+		dprintk("RPC: %5u %s: program %u, version %u unsupported by "
+				"server %s\n", task->tk_pid, __func__,
+				(unsigned int)task->tk_client->cl_prog,
+				(unsigned int)task->tk_client->cl_vers,
+				task->tk_client->cl_server);
+		error = -EPROTONOSUPPORT;
+		goto out_err;
+	case RPC_PROC_UNAVAIL:
+		dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
+				"version %u on server %s\n",
+				task->tk_pid, __func__,
+				rpc_proc_name(task),
+				task->tk_client->cl_prog,
+				task->tk_client->cl_vers,
+				task->tk_client->cl_server);
+		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:
+	task->tk_client->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_eio:
+	error = -EIO;
+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 int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
+{
+	return 0;
+}
+
+static int rpcproc_decode_null(void *rqstp, __be32 *data, 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, int flags)
+{
+	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, flags);
+	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";
+	char *p, action[KSYM_SYMBOL_LEN];
+
+	if (RPC_IS_QUEUED(task))
+		rpc_waitq = rpc_qname(task->tk_waitqueue);
+
+	/* map tk_action pointer to a function name; then trim off
+	 * the "+0x0 [sunrpc]" */
+	sprint_symbol(action, (unsigned long)task->tk_action);
+	p = strchr(action, '+');
+	if (p)
+		*p = '\0';
+
+	printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
+		task->tk_pid, task->tk_flags, task->tk_status,
+		clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
+		clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
+		action, rpc_waitq);
+}
+
+void rpc_show_tasks(void)
+{
+	struct rpc_clnt *clnt;
+	struct rpc_task *task;
+	int header = 0;
+
+	spin_lock(&rpc_client_lock);
+	list_for_each_entry(clnt, &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(&rpc_client_lock);
+}
+#endif