v4.19.13 snapshot.
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
new file mode 100644
index 0000000..8ea2f5f
--- /dev/null
+++ b/net/sunrpc/clnt.c
@@ -0,0 +1,2894 @@
+/*
+ * 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_decode(struct rpc_task *task);
+static void call_bind(struct rpc_task *task);
+static void call_bind_status(struct rpc_task *task);
+static void call_transmit(struct rpc_task *task);
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+static void call_bc_transmit(struct rpc_task *task);
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+static void call_status(struct rpc_task *task);
+static void call_transmit_status(struct rpc_task *task);
+static void call_refresh(struct rpc_task *task);
+static void call_refreshresult(struct rpc_task *task);
+static void call_timeout(struct rpc_task *task);
+static void call_connect(struct rpc_task *task);
+static void call_connect_status(struct rpc_task *task);
+
+static __be32 *rpc_encode_header(struct rpc_task *task);
+static __be32 *rpc_verify_header(struct rpc_task *task);
+static int rpc_ping(struct rpc_clnt *clnt);
+
+static void rpc_register_client(struct rpc_clnt *clnt)
+{
+ struct net *net = rpc_net_ns(clnt);
+ struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+ spin_lock(&sn->rpc_client_lock);
+ list_add(&clnt->cl_clients, &sn->all_clients);
+ spin_unlock(&sn->rpc_client_lock);
+}
+
+static void rpc_unregister_client(struct rpc_clnt *clnt)
+{
+ struct net *net = rpc_net_ns(clnt);
+ struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+ spin_lock(&sn->rpc_client_lock);
+ list_del(&clnt->cl_clients);
+ spin_unlock(&sn->rpc_client_lock);
+}
+
+static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
+{
+ rpc_remove_client_dir(clnt);
+}
+
+static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
+{
+ struct net *net = rpc_net_ns(clnt);
+ struct super_block *pipefs_sb;
+
+ pipefs_sb = rpc_get_sb_net(net);
+ if (pipefs_sb) {
+ __rpc_clnt_remove_pipedir(clnt);
+ rpc_put_sb_net(net);
+ }
+}
+
+static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
+ struct rpc_clnt *clnt)
+{
+ static uint32_t clntid;
+ const char *dir_name = clnt->cl_program->pipe_dir_name;
+ char name[15];
+ struct dentry *dir, *dentry;
+
+ dir = rpc_d_lookup_sb(sb, dir_name);
+ if (dir == NULL) {
+ pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
+ return dir;
+ }
+ for (;;) {
+ snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
+ name[sizeof(name) - 1] = '\0';
+ dentry = rpc_create_client_dir(dir, name, clnt);
+ if (!IS_ERR(dentry))
+ break;
+ if (dentry == ERR_PTR(-EEXIST))
+ continue;
+ printk(KERN_INFO "RPC: Couldn't create pipefs entry"
+ " %s/%s, error %ld\n",
+ dir_name, name, PTR_ERR(dentry));
+ break;
+ }
+ dput(dir);
+ return dentry;
+}
+
+static int
+rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
+{
+ struct dentry *dentry;
+
+ if (clnt->cl_program->pipe_dir_name != NULL) {
+ dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+ }
+ return 0;
+}
+
+static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
+{
+ if (clnt->cl_program->pipe_dir_name == NULL)
+ return 1;
+
+ switch (event) {
+ case RPC_PIPEFS_MOUNT:
+ if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
+ return 1;
+ if (atomic_read(&clnt->cl_count) == 0)
+ return 1;
+ break;
+ case RPC_PIPEFS_UMOUNT:
+ if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
+ return 1;
+ break;
+ }
+ return 0;
+}
+
+static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
+ struct super_block *sb)
+{
+ struct dentry *dentry;
+
+ 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_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:
+ 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)
+ clnt->cl_softrtry = 0;
+
+ 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];
+
+ 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;
+
+ return rpc_create_xprt(args, xprt);
+}
+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_noretranstimeo = clnt->cl_noretranstimeo;
+ new->cl_discrtry = clnt->cl_discrtry;
+ new->cl_chatty = clnt->cl_chatty;
+ return new;
+
+out_err:
+ dprintk("RPC: %s: returned error %d\n", __func__, err);
+ return ERR_PTR(err);
+}
+
+/**
+ * rpc_clone_client - Clone an RPC client structure
+ *
+ * @clnt: RPC client whose parameters are copied
+ *
+ * Returns a fresh RPC client or an ERR_PTR.
+ */
+struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
+{
+ struct rpc_create_args args = {
+ .program = clnt->cl_program,
+ .prognumber = clnt->cl_prog,
+ .version = clnt->cl_vers,
+ .authflavor = clnt->cl_auth->au_flavor,
+ };
+ return __rpc_clone_client(&args, clnt);
+}
+EXPORT_SYMBOL_GPL(rpc_clone_client);
+
+/**
+ * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
+ *
+ * @clnt: RPC client whose parameters are copied
+ * @flavor: security flavor for new client
+ *
+ * Returns a fresh RPC client or an ERR_PTR.
+ */
+struct rpc_clnt *
+rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
+{
+ struct rpc_create_args args = {
+ .program = clnt->cl_program,
+ .prognumber = clnt->cl_prog,
+ .version = clnt->cl_vers,
+ .authflavor = flavor,
+ };
+ return __rpc_clone_client(&args, clnt);
+}
+EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
+
+/**
+ * rpc_switch_client_transport: switch the RPC transport on the fly
+ * @clnt: pointer to a struct rpc_clnt
+ * @args: pointer to the new transport arguments
+ * @timeout: pointer to the new timeout parameters
+ *
+ * This function allows the caller to switch the RPC transport for the
+ * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
+ * server, for instance. It assumes that the caller has ensured that
+ * there are no active RPC tasks by using some form of locking.
+ *
+ * Returns zero if "clnt" is now using the new xprt. Otherwise a
+ * negative errno is returned, and "clnt" continues to use the old
+ * xprt.
+ */
+int rpc_switch_client_transport(struct rpc_clnt *clnt,
+ struct xprt_create *args,
+ const struct rpc_timeout *timeout)
+{
+ const struct rpc_timeout *old_timeo;
+ rpc_authflavor_t pseudoflavor;
+ struct rpc_xprt_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) {
+ if (!RPC_IS_ACTIVATED(rovr))
+ continue;
+ if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
+ rovr->tk_flags |= RPC_TASK_KILLED;
+ rpc_exit(rovr, -EIO);
+ if (RPC_IS_QUEUED(rovr))
+ rpc_wake_up_queued_task(rovr->tk_waitqueue,
+ rovr);
+ }
+ }
+ spin_unlock(&clnt->cl_lock);
+}
+EXPORT_SYMBOL_GPL(rpc_killall_tasks);
+
+/*
+ * Properly shut down an RPC client, terminating all outstanding
+ * requests.
+ */
+void rpc_shutdown_client(struct rpc_clnt *clnt)
+{
+ might_sleep();
+
+ dprintk_rcu("RPC: shutting down %s client for %s\n",
+ clnt->cl_program->name,
+ rcu_dereference(clnt->cl_xprt)->servername);
+
+ while (!list_empty(&clnt->cl_tasks)) {
+ rpc_killall_tasks(clnt);
+ wait_event_timeout(destroy_wait,
+ list_empty(&clnt->cl_tasks), 1*HZ);
+ }
+
+ rpc_release_client(clnt);
+}
+EXPORT_SYMBOL_GPL(rpc_shutdown_client);
+
+/*
+ * Free an RPC client
+ */
+static struct rpc_clnt *
+rpc_free_client(struct rpc_clnt *clnt)
+{
+ struct rpc_clnt *parent = NULL;
+
+ dprintk_rcu("RPC: destroying %s client for %s\n",
+ clnt->cl_program->name,
+ rcu_dereference(clnt->cl_xprt)->servername);
+ if (clnt->cl_parent != clnt)
+ parent = clnt->cl_parent;
+ rpc_clnt_debugfs_unregister(clnt);
+ rpc_clnt_remove_pipedir(clnt);
+ rpc_unregister_client(clnt);
+ rpc_free_iostats(clnt->cl_metrics);
+ clnt->cl_metrics = NULL;
+ xprt_put(rcu_dereference_raw(clnt->cl_xprt));
+ xprt_iter_destroy(&clnt->cl_xpi);
+ rpciod_down();
+ rpc_free_clid(clnt);
+ kfree(clnt);
+ return parent;
+}
+
+/*
+ * Free an RPC client
+ */
+static struct rpc_clnt *
+rpc_free_auth(struct rpc_clnt *clnt)
+{
+ if (clnt->cl_auth == NULL)
+ return rpc_free_client(clnt);
+
+ /*
+ * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
+ * release remaining GSS contexts. This mechanism ensures
+ * that it can do so safely.
+ */
+ atomic_inc(&clnt->cl_count);
+ rpcauth_release(clnt->cl_auth);
+ clnt->cl_auth = NULL;
+ if (atomic_dec_and_test(&clnt->cl_count))
+ return rpc_free_client(clnt);
+ return NULL;
+}
+
+/*
+ * Release reference to the RPC client
+ */
+void
+rpc_release_client(struct rpc_clnt *clnt)
+{
+ dprintk("RPC: rpc_release_client(%p)\n", clnt);
+
+ do {
+ if (list_empty(&clnt->cl_tasks))
+ wake_up(&destroy_wait);
+ if (!atomic_dec_and_test(&clnt->cl_count))
+ break;
+ clnt = rpc_free_auth(clnt);
+ } while (clnt != NULL);
+}
+EXPORT_SYMBOL_GPL(rpc_release_client);
+
+/**
+ * rpc_bind_new_program - bind a new RPC program to an existing client
+ * @old: old rpc_client
+ * @program: rpc program to set
+ * @vers: rpc program version
+ *
+ * Clones the rpc client and sets up a new RPC program. This is mainly
+ * of use for enabling different RPC programs to share the same transport.
+ * The Sun NFSv2/v3 ACL protocol can do this.
+ */
+struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
+ const struct rpc_program *program,
+ u32 vers)
+{
+ struct rpc_create_args args = {
+ .program = program,
+ .prognumber = program->number,
+ .version = vers,
+ .authflavor = old->cl_auth->au_flavor,
+ };
+ struct rpc_clnt *clnt;
+ int err;
+
+ clnt = __rpc_clone_client(&args, old);
+ if (IS_ERR(clnt))
+ goto out;
+ err = rpc_ping(clnt);
+ if (err != 0) {
+ rpc_shutdown_client(clnt);
+ clnt = ERR_PTR(err);
+ }
+out:
+ return clnt;
+}
+EXPORT_SYMBOL_GPL(rpc_bind_new_program);
+
+void rpc_task_release_transport(struct rpc_task *task)
+{
+ struct rpc_xprt *xprt = task->tk_xprt;
+
+ if (xprt) {
+ task->tk_xprt = NULL;
+ 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;
+
+ 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);
+ }
+ rpc_task_release_transport(task);
+}
+
+static
+void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
+{
+ if (!task->tk_xprt)
+ task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
+}
+
+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_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;
+ if (msg->rpc_cred != NULL)
+ task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
+ }
+}
+
+/*
+ * Default callback for async RPC calls
+ */
+static void
+rpc_default_callback(struct rpc_task *task, void *data)
+{
+}
+
+static const struct rpc_call_ops rpc_default_ops = {
+ .rpc_call_done = rpc_default_callback,
+};
+
+/**
+ * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
+ * @task_setup_data: pointer to task initialisation data
+ */
+struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
+{
+ struct rpc_task *task;
+
+ task = rpc_new_task(task_setup_data);
+
+ 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)
+/**
+ * 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 xdr_buf *xbufp = &req->rq_snd_buf;
+ struct rpc_task_setup task_setup_data = {
+ .callback_ops = &rpc_default_ops,
+ .flags = RPC_TASK_SOFTCONN,
+ };
+
+ 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);
+ task->tk_rqstp = req;
+
+ /*
+ * Set up the xdr_buf length.
+ * This also indicates that the buffer is XDR encoded already.
+ */
+ xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
+ xbufp->tail[0].iov_len;
+
+ task->tk_action = call_bc_transmit;
+ atomic_inc(&task->tk_count);
+ WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
+ rpc_execute(task);
+
+ dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
+ return task;
+}
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+void
+rpc_call_start(struct rpc_task *task)
+{
+ task->tk_action = call_start;
+}
+EXPORT_SYMBOL_GPL(rpc_call_start);
+
+/**
+ * rpc_peeraddr - extract remote peer address from clnt's xprt
+ * @clnt: RPC client structure
+ * @buf: target buffer
+ * @bufsize: length of target buffer
+ *
+ * Returns the number of bytes that are actually in the stored address.
+ */
+size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
+{
+ size_t bytes;
+ struct rpc_xprt *xprt;
+
+ rcu_read_lock();
+ xprt = rcu_dereference(clnt->cl_xprt);
+
+ bytes = xprt->addrlen;
+ if (bytes > bufsize)
+ bytes = bufsize;
+ memcpy(buf, &xprt->addr, bytes);
+ rcu_read_unlock();
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(rpc_peeraddr);
+
+/**
+ * rpc_peeraddr2str - return remote peer address in printable format
+ * @clnt: RPC client structure
+ * @format: address format
+ *
+ * NB: the lifetime of the memory referenced by the returned pointer is
+ * the same as the rpc_xprt itself. As long as the caller uses this
+ * pointer, it must hold the RCU read lock.
+ */
+const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
+ enum rpc_display_format_t format)
+{
+ struct rpc_xprt *xprt;
+
+ xprt = rcu_dereference(clnt->cl_xprt);
+
+ if (xprt->address_strings[format] != NULL)
+ return xprt->address_strings[format];
+ else
+ return "unprintable";
+}
+EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
+
+static const struct sockaddr_in rpc_inaddr_loopback = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_ANY),
+};
+
+static const struct sockaddr_in6 rpc_in6addr_loopback = {
+ .sin6_family = AF_INET6,
+ .sin6_addr = IN6ADDR_ANY_INIT,
+};
+
+/*
+ * Try a getsockname() on a connected datagram socket. Using a
+ * connected datagram socket prevents leaving a socket in TIME_WAIT.
+ * This conserves the ephemeral port number space.
+ *
+ * Returns zero and fills in "buf" if successful; otherwise, a
+ * negative errno is returned.
+ */
+static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
+ struct sockaddr *buf)
+{
+ 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);
+
+/**
+ * rpc_force_rebind - force transport to check that remote port is unchanged
+ * @clnt: client to rebind
+ *
+ */
+void rpc_force_rebind(struct rpc_clnt *clnt)
+{
+ if (clnt->cl_autobind) {
+ rcu_read_lock();
+ xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
+ rcu_read_unlock();
+ }
+}
+EXPORT_SYMBOL_GPL(rpc_force_rebind);
+
+/*
+ * Restart an (async) RPC call from the call_prepare state.
+ * Usually called from within the exit handler.
+ */
+int
+rpc_restart_call_prepare(struct rpc_task *task)
+{
+ if (RPC_ASSASSINATED(task))
+ return 0;
+ task->tk_action = call_start;
+ task->tk_status = 0;
+ if (task->tk_ops->rpc_call_prepare != NULL)
+ task->tk_action = rpc_prepare_task;
+ return 1;
+}
+EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
+
+/*
+ * Restart an (async) RPC call. Usually called from within the
+ * exit handler.
+ */
+int
+rpc_restart_call(struct rpc_task *task)
+{
+ if (RPC_ASSASSINATED(task))
+ return 0;
+ task->tk_action = call_start;
+ task->tk_status = 0;
+ return 1;
+}
+EXPORT_SYMBOL_GPL(rpc_restart_call);
+
+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";
+}
+
+/*
+ * 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) {
+ xprt_request_init(task);
+ task->tk_action = call_refresh;
+ return;
+ }
+
+ printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
+ __func__, status);
+ rpc_exit(task, -EIO);
+ return;
+ }
+
+ /*
+ * Even though there was an error, we may have acquired
+ * a request slot somehow. Make sure not to leak it.
+ */
+ if (task->tk_rqstp) {
+ printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
+ __func__, status);
+ xprt_release(task);
+ }
+
+ switch (status) {
+ case -ENOMEM:
+ rpc_delay(task, HZ >> 2);
+ /* fall through */
+ case -EAGAIN: /* woken up; retry */
+ task->tk_action = call_retry_reserve;
+ return;
+ case -EIO: /* probably a shutdown */
+ break;
+ default:
+ printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
+ __func__, status);
+ break;
+ }
+ rpc_exit(task, status);
+}
+
+/*
+ * 1c. Retry reserving an RPC call slot
+ */
+static void
+call_retry_reserve(struct rpc_task *task)
+{
+ dprint_status(task);
+
+ task->tk_status = 0;
+ task->tk_action = call_reserveresult;
+ xprt_retry_reserve(task);
+}
+
+/*
+ * 2. Bind and/or refresh the credentials
+ */
+static void
+call_refresh(struct rpc_task *task)
+{
+ dprint_status(task);
+
+ task->tk_action = call_refreshresult;
+ task->tk_status = 0;
+ task->tk_client->cl_stats->rpcauthrefresh++;
+ rpcauth_refreshcred(task);
+}
+
+/*
+ * 2a. Process the results of a credential refresh
+ */
+static void
+call_refreshresult(struct rpc_task *task)
+{
+ int status = task->tk_status;
+
+ dprint_status(task);
+
+ task->tk_status = 0;
+ task->tk_action = call_refresh;
+ switch (status) {
+ case 0:
+ if (rpcauth_uptodatecred(task)) {
+ task->tk_action = call_allocate;
+ return;
+ }
+ /* 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_exit(task, status);
+}
+
+/*
+ * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
+ * (Note: buffer memory is freed in xprt_release).
+ */
+static void
+call_allocate(struct rpc_task *task)
+{
+ unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+ const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
+ int status;
+
+ 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;
+
+ status = xprt->ops->buf_alloc(task);
+ xprt_inject_disconnect(xprt);
+ if (status == 0)
+ return;
+ if (status != -ENOMEM) {
+ rpc_exit(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_exit(task, -ERESTARTSYS);
+}
+
+static inline int
+rpc_task_need_encode(struct rpc_task *task)
+{
+ return task->tk_rqstp->rq_snd_buf.len == 0;
+}
+
+static inline void
+rpc_task_force_reencode(struct rpc_task *task)
+{
+ task->tk_rqstp->rq_snd_buf.len = 0;
+ task->tk_rqstp->rq_bytes_sent = 0;
+}
+
+/*
+ * 3. Encode arguments of an RPC call
+ */
+static void
+rpc_xdr_encode(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ kxdreproc_t encode;
+ __be32 *p;
+
+ dprint_status(task);
+
+ 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);
+
+ p = rpc_encode_header(task);
+ if (p == NULL) {
+ printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
+ rpc_exit(task, -EIO);
+ return;
+ }
+
+ encode = task->tk_msg.rpc_proc->p_encode;
+ if (encode == NULL)
+ return;
+
+ task->tk_status = rpcauth_wrap_req(task, encode, req, p,
+ task->tk_msg.rpc_argp);
+}
+
+/*
+ * 4. Get the server port number if not yet set
+ */
+static void
+call_bind(struct rpc_task *task)
+{
+ struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
+
+ dprint_status(task);
+
+ task->tk_action = call_connect;
+ if (!xprt_bound(xprt)) {
+ task->tk_action = call_bind_status;
+ task->tk_timeout = xprt->bind_timeout;
+ xprt->ops->rpcbind(task);
+ }
+}
+
+/*
+ * 4a. Sort out bind result
+ */
+static void
+call_bind_status(struct rpc_task *task)
+{
+ int status = -EIO;
+
+ if (task->tk_status >= 0) {
+ dprint_status(task);
+ task->tk_status = 0;
+ task->tk_action = call_connect;
+ return;
+ }
+
+ trace_rpc_bind_status(task);
+ switch (task->tk_status) {
+ case -ENOMEM:
+ dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
+ rpc_delay(task, HZ >> 2);
+ goto retry_timeout;
+ case -EACCES:
+ dprintk("RPC: %5u remote rpcbind: RPC program/version "
+ "unavailable\n", task->tk_pid);
+ /* fail immediately if this is an RPC ping */
+ if (task->tk_msg.rpc_proc->p_proc == 0) {
+ status = -EOPNOTSUPP;
+ break;
+ }
+ if (task->tk_rebind_retry == 0)
+ break;
+ task->tk_rebind_retry--;
+ rpc_delay(task, 3*HZ);
+ goto retry_timeout;
+ case -ETIMEDOUT:
+ dprintk("RPC: %5u rpcbind request timed out\n",
+ task->tk_pid);
+ goto retry_timeout;
+ case -EPFNOSUPPORT:
+ /* server doesn't support any rpcbind version we know of */
+ dprintk("RPC: %5u unrecognized remote rpcbind service\n",
+ task->tk_pid);
+ break;
+ case -EPROTONOSUPPORT:
+ dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
+ task->tk_pid);
+ goto retry_timeout;
+ case -ECONNREFUSED: /* connection problems */
+ case -ECONNRESET:
+ case -ECONNABORTED:
+ case -ENOTCONN:
+ case -EHOSTDOWN:
+ case -ENETDOWN:
+ case -EHOSTUNREACH:
+ case -ENETUNREACH:
+ case -ENOBUFS:
+ case -EPIPE:
+ dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
+ task->tk_pid, task->tk_status);
+ if (!RPC_IS_SOFTCONN(task)) {
+ rpc_delay(task, 5*HZ);
+ goto retry_timeout;
+ }
+ status = task->tk_status;
+ break;
+ default:
+ dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
+ task->tk_pid, -task->tk_status);
+ }
+
+ rpc_exit(task, status);
+ return;
+
+retry_timeout:
+ task->tk_status = 0;
+ task->tk_action = call_timeout;
+}
+
+/*
+ * 4b. Connect to the RPC server
+ */
+static void
+call_connect(struct rpc_task *task)
+{
+ struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
+
+ dprintk("RPC: %5u call_connect xprt %p %s connected\n",
+ task->tk_pid, xprt,
+ (xprt_connected(xprt) ? "is" : "is not"));
+
+ task->tk_action = call_transmit;
+ if (!xprt_connected(xprt)) {
+ task->tk_action = call_connect_status;
+ if (task->tk_status < 0)
+ return;
+ if (task->tk_flags & RPC_TASK_NOCONNECT) {
+ rpc_exit(task, -ENOTCONN);
+ return;
+ }
+ xprt_connect(task);
+ }
+}
+
+/*
+ * 4c. Sort out connect result
+ */
+static void
+call_connect_status(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ int status = task->tk_status;
+
+ dprint_status(task);
+
+ trace_rpc_connect_status(task);
+ 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);
+ task->tk_action = call_bind;
+ return;
+ }
+ /* fall through */
+ case -ECONNRESET:
+ case -ECONNABORTED:
+ case -ENETDOWN:
+ case -ENETUNREACH:
+ case -EHOSTUNREACH:
+ case -EADDRINUSE:
+ case -ENOBUFS:
+ case -EPIPE:
+ 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 -EAGAIN:
+ /* Check for timeouts before looping back to call_bind */
+ case -ETIMEDOUT:
+ task->tk_action = call_timeout;
+ return;
+ case 0:
+ clnt->cl_stats->netreconn++;
+ task->tk_action = call_transmit;
+ return;
+ }
+ rpc_exit(task, status);
+}
+
+/*
+ * 5. Transmit the RPC request, and wait for reply
+ */
+static void
+call_transmit(struct rpc_task *task)
+{
+ int is_retrans = RPC_WAS_SENT(task);
+
+ dprint_status(task);
+
+ task->tk_action = call_status;
+ if (task->tk_status < 0)
+ return;
+ if (!xprt_prepare_transmit(task))
+ return;
+ task->tk_action = call_transmit_status;
+ /* Encode here so that rpcsec_gss can use correct sequence number. */
+ if (rpc_task_need_encode(task)) {
+ rpc_xdr_encode(task);
+ /* Did the encode result in an error condition? */
+ if (task->tk_status != 0) {
+ /* Was the error nonfatal? */
+ if (task->tk_status == -EAGAIN)
+ rpc_delay(task, HZ >> 4);
+ else
+ rpc_exit(task, task->tk_status);
+ return;
+ }
+ }
+ xprt_transmit(task);
+ if (task->tk_status < 0)
+ return;
+ if (is_retrans)
+ task->tk_client->cl_stats->rpcretrans++;
+ /*
+ * On success, ensure that we call xprt_end_transmit() before sleeping
+ * in order to allow access to the socket to other RPC requests.
+ */
+ call_transmit_status(task);
+ if (rpc_reply_expected(task))
+ return;
+ task->tk_action = rpc_exit_task;
+ rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
+}
+
+/*
+ * 5a. Handle cleanup after a transmission
+ */
+static void
+call_transmit_status(struct rpc_task *task)
+{
+ task->tk_action = call_status;
+
+ /*
+ * Common case: success. Force the compiler to put this
+ * test first.
+ */
+ if (task->tk_status == 0) {
+ xprt_end_transmit(task);
+ rpc_task_force_reencode(task);
+ return;
+ }
+
+ switch (task->tk_status) {
+ case -EAGAIN:
+ case -ENOBUFS:
+ break;
+ default:
+ dprint_status(task);
+ xprt_end_transmit(task);
+ rpc_task_force_reencode(task);
+ break;
+ /*
+ * Special cases: if we've been waiting on the
+ * socket's write_space() callback, or if the
+ * socket just returned a connection error,
+ * then hold onto the transport lock.
+ */
+ case -ECONNREFUSED:
+ case -EHOSTDOWN:
+ case -ENETDOWN:
+ case -EHOSTUNREACH:
+ case -ENETUNREACH:
+ case -EPERM:
+ if (RPC_IS_SOFTCONN(task)) {
+ xprt_end_transmit(task);
+ if (!task->tk_msg.rpc_proc->p_proc)
+ trace_xprt_ping(task->tk_xprt,
+ task->tk_status);
+ rpc_exit(task, task->tk_status);
+ break;
+ }
+ /* fall through */
+ case -ECONNRESET:
+ case -ECONNABORTED:
+ case -EADDRINUSE:
+ case -ENOTCONN:
+ case -EPIPE:
+ rpc_task_force_reencode(task);
+ }
+}
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+/*
+ * 5b. Send the backchannel RPC reply. On error, drop the reply. In
+ * addition, disconnect on connectivity errors.
+ */
+static void
+call_bc_transmit(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+
+ if (!xprt_prepare_transmit(task))
+ goto out_retry;
+
+ if (task->tk_status < 0) {
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ goto out_done;
+ }
+ if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
+ req->rq_bytes_sent = 0;
+
+ xprt_transmit(task);
+
+ if (task->tk_status == -EAGAIN)
+ goto out_nospace;
+
+ xprt_end_transmit(task);
+ 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 -ETIMEDOUT:
+ /*
+ * Problem reaching the server. Disconnect and let the
+ * forechannel reestablish the connection. The server will
+ * have to retransmit the backchannel request and we'll
+ * reprocess it. Since these ops are idempotent, there's no
+ * need to cache our reply at this time.
+ */
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ xprt_conditional_disconnect(req->rq_xprt,
+ req->rq_connect_cookie);
+ break;
+ default:
+ /*
+ * We were unable to reply and will have to drop the
+ * request. The server should reconnect and retransmit.
+ */
+ WARN_ON_ONCE(task->tk_status == -EAGAIN);
+ printk(KERN_NOTICE "RPC: Could not send backchannel reply "
+ "error: %d\n", task->tk_status);
+ break;
+ }
+ rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
+out_done:
+ task->tk_action = rpc_exit_task;
+ return;
+out_nospace:
+ req->rq_connect_cookie = req->rq_xprt->connect_cookie;
+out_retry:
+ task->tk_status = 0;
+}
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+/*
+ * 6. Sort out the RPC call status
+ */
+static void
+call_status(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ struct rpc_rqst *req = task->tk_rqstp;
+ int status;
+
+ if (!task->tk_msg.rpc_proc->p_proc)
+ trace_xprt_ping(task->tk_xprt, task->tk_status);
+
+ if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
+ task->tk_status = req->rq_reply_bytes_recvd;
+
+ dprint_status(task);
+
+ status = task->tk_status;
+ if (status >= 0) {
+ task->tk_action = call_decode;
+ return;
+ }
+
+ trace_rpc_call_status(task);
+ task->tk_status = 0;
+ switch(status) {
+ case -EHOSTDOWN:
+ case -ENETDOWN:
+ case -EHOSTUNREACH:
+ case -ENETUNREACH:
+ case -EPERM:
+ if (RPC_IS_SOFTCONN(task)) {
+ rpc_exit(task, status);
+ break;
+ }
+ /*
+ * Delay any retries for 3 seconds, then handle as if it
+ * were a timeout.
+ */
+ rpc_delay(task, 3*HZ);
+ /* fall through */
+ case -ETIMEDOUT:
+ task->tk_action = call_timeout;
+ break;
+ case -ECONNREFUSED:
+ case -ECONNRESET:
+ case -ECONNABORTED:
+ rpc_force_rebind(clnt);
+ /* fall through */
+ case -EADDRINUSE:
+ rpc_delay(task, 3*HZ);
+ /* fall through */
+ case -EPIPE:
+ case -ENOTCONN:
+ task->tk_action = call_bind;
+ break;
+ case -ENOBUFS:
+ rpc_delay(task, HZ>>2);
+ /* fall through */
+ case -EAGAIN:
+ task->tk_action = call_transmit;
+ break;
+ case -EIO:
+ /* shutdown or soft timeout */
+ rpc_exit(task, status);
+ break;
+ default:
+ if (clnt->cl_chatty)
+ printk("%s: RPC call returned error %d\n",
+ clnt->cl_program->name, -status);
+ rpc_exit(task, status);
+ }
+}
+
+/*
+ * 6a. Handle RPC timeout
+ * We do not release the request slot, so we keep using the
+ * same XID for all retransmits.
+ */
+static void
+call_timeout(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+
+ if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
+ dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
+ goto retry;
+ }
+
+ dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
+ task->tk_timeouts++;
+
+ if (RPC_IS_SOFTCONN(task)) {
+ rpc_exit(task, -ETIMEDOUT);
+ return;
+ }
+ if (RPC_IS_SOFT(task)) {
+ if (clnt->cl_chatty) {
+ printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
+ clnt->cl_program->name,
+ task->tk_xprt->servername);
+ }
+ if (task->tk_flags & RPC_TASK_TIMEOUT)
+ rpc_exit(task, -ETIMEDOUT);
+ else
+ rpc_exit(task, -EIO);
+ return;
+ }
+
+ if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
+ task->tk_flags |= RPC_CALL_MAJORSEEN;
+ if (clnt->cl_chatty) {
+ printk(KERN_NOTICE "%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);
+
+retry:
+ task->tk_action = call_bind;
+ task->tk_status = 0;
+}
+
+/*
+ * 7. Decode the RPC reply
+ */
+static void
+call_decode(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ struct rpc_rqst *req = task->tk_rqstp;
+ kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
+ __be32 *p;
+
+ dprint_status(task);
+
+ if (task->tk_flags & RPC_CALL_MAJORSEEN) {
+ if (clnt->cl_chatty) {
+ printk(KERN_NOTICE "%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();
+ req->rq_rcv_buf.len = req->rq_private_buf.len;
+
+ /* Check that the softirq receive buffer is valid */
+ WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
+ sizeof(req->rq_rcv_buf)) != 0);
+
+ if (req->rq_rcv_buf.len < 12) {
+ if (!RPC_IS_SOFT(task)) {
+ task->tk_action = call_bind;
+ goto out_retry;
+ }
+ dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
+ clnt->cl_program->name, task->tk_status);
+ task->tk_action = call_timeout;
+ goto out_retry;
+ }
+
+ p = rpc_verify_header(task);
+ if (IS_ERR(p)) {
+ if (p == ERR_PTR(-EAGAIN))
+ goto out_retry;
+ return;
+ }
+
+ task->tk_action = rpc_exit_task;
+
+ if (decode) {
+ task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
+ task->tk_msg.rpc_resp);
+ }
+ dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
+ task->tk_status);
+ return;
+out_retry:
+ task->tk_status = 0;
+ /* Note: rpc_verify_header() may have freed the RPC slot */
+ if (task->tk_rqstp == req) {
+ req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
+ if (task->tk_client->cl_discrtry)
+ xprt_conditional_disconnect(req->rq_xprt,
+ req->rq_connect_cookie);
+ }
+}
+
+static __be32 *
+rpc_encode_header(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ struct rpc_rqst *req = task->tk_rqstp;
+ __be32 *p = req->rq_svec[0].iov_base;
+
+ /* FIXME: check buffer size? */
+
+ p = xprt_skip_transport_header(req->rq_xprt, p);
+ *p++ = req->rq_xid; /* XID */
+ *p++ = htonl(RPC_CALL); /* CALL */
+ *p++ = htonl(RPC_VERSION); /* RPC version */
+ *p++ = htonl(clnt->cl_prog); /* program number */
+ *p++ = htonl(clnt->cl_vers); /* program version */
+ *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
+ p = rpcauth_marshcred(task, p);
+ req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
+ return p;
+}
+
+static __be32 *
+rpc_verify_header(struct rpc_task *task)
+{
+ struct rpc_clnt *clnt = task->tk_client;
+ struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
+ int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
+ __be32 *p = iov->iov_base;
+ u32 n;
+ int error = -EACCES;
+
+ if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
+ /* RFC-1014 says that the representation of XDR data must be a
+ * multiple of four bytes
+ * - if it isn't pointer subtraction in the NFS client may give
+ * undefined results
+ */
+ dprintk("RPC: %5u %s: XDR representation not a multiple of"
+ " 4 bytes: 0x%x\n", task->tk_pid, __func__,
+ task->tk_rqstp->rq_rcv_buf.len);
+ error = -EIO;
+ goto out_err;
+ }
+ if ((len -= 3) < 0)
+ goto out_overflow;
+
+ p += 1; /* skip XID */
+ if ((n = ntohl(*p++)) != RPC_REPLY) {
+ dprintk("RPC: %5u %s: not an RPC reply: %x\n",
+ task->tk_pid, __func__, n);
+ error = -EIO;
+ goto out_garbage;
+ }
+
+ if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
+ if (--len < 0)
+ goto out_overflow;
+ switch ((n = ntohl(*p++))) {
+ case RPC_AUTH_ERROR:
+ break;
+ case RPC_MISMATCH:
+ dprintk("RPC: %5u %s: RPC call version mismatch!\n",
+ task->tk_pid, __func__);
+ error = -EPROTONOSUPPORT;
+ goto out_err;
+ default:
+ dprintk("RPC: %5u %s: RPC call rejected, "
+ "unknown error: %x\n",
+ task->tk_pid, __func__, n);
+ error = -EIO;
+ goto out_err;
+ }
+ if (--len < 0)
+ goto out_overflow;
+ switch ((n = ntohl(*p++))) {
+ case RPC_AUTH_REJECTEDCRED:
+ case RPC_AUTH_REJECTEDVERF:
+ case RPCSEC_GSS_CREDPROBLEM:
+ case RPCSEC_GSS_CTXPROBLEM:
+ if (!task->tk_cred_retry)
+ break;
+ task->tk_cred_retry--;
+ dprintk("RPC: %5u %s: retry stale creds\n",
+ task->tk_pid, __func__);
+ rpcauth_invalcred(task);
+ /* Ensure we obtain a new XID! */
+ xprt_release(task);
+ task->tk_action = call_reserve;
+ goto out_retry;
+ case RPC_AUTH_BADCRED:
+ case RPC_AUTH_BADVERF:
+ /* possibly garbled cred/verf? */
+ if (!task->tk_garb_retry)
+ break;
+ task->tk_garb_retry--;
+ dprintk("RPC: %5u %s: retry garbled creds\n",
+ task->tk_pid, __func__);
+ task->tk_action = call_bind;
+ goto out_retry;
+ case RPC_AUTH_TOOWEAK:
+ printk(KERN_NOTICE "RPC: server %s requires stronger "
+ "authentication.\n",
+ task->tk_xprt->servername);
+ break;
+ default:
+ dprintk("RPC: %5u %s: unknown auth error: %x\n",
+ task->tk_pid, __func__, n);
+ error = -EIO;
+ }
+ dprintk("RPC: %5u %s: call rejected %d\n",
+ task->tk_pid, __func__, n);
+ goto out_err;
+ }
+ p = rpcauth_checkverf(task, p);
+ if (IS_ERR(p)) {
+ error = PTR_ERR(p);
+ dprintk("RPC: %5u %s: auth check failed with %d\n",
+ task->tk_pid, __func__, error);
+ goto out_garbage; /* bad verifier, retry */
+ }
+ len = p - (__be32 *)iov->iov_base - 1;
+ if (len < 0)
+ goto out_overflow;
+ switch ((n = ntohl(*p++))) {
+ case RPC_SUCCESS:
+ return p;
+ case RPC_PROG_UNAVAIL:
+ dprintk("RPC: %5u %s: program %u is unsupported "
+ "by server %s\n", task->tk_pid, __func__,
+ (unsigned int)clnt->cl_prog,
+ task->tk_xprt->servername);
+ 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)clnt->cl_prog,
+ (unsigned int)clnt->cl_vers,
+ task->tk_xprt->servername);
+ 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),
+ clnt->cl_prog, clnt->cl_vers,
+ task->tk_xprt->servername);
+ error = -EOPNOTSUPP;
+ goto out_err;
+ case RPC_GARBAGE_ARGS:
+ dprintk("RPC: %5u %s: server saw garbage\n",
+ task->tk_pid, __func__);
+ break; /* retry */
+ default:
+ dprintk("RPC: %5u %s: server accept status: %x\n",
+ task->tk_pid, __func__, n);
+ /* Also retry */
+ }
+
+out_garbage:
+ clnt->cl_stats->rpcgarbage++;
+ if (task->tk_garb_retry) {
+ task->tk_garb_retry--;
+ dprintk("RPC: %5u %s: retrying\n",
+ task->tk_pid, __func__);
+ task->tk_action = call_bind;
+out_retry:
+ return ERR_PTR(-EAGAIN);
+ }
+out_err:
+ rpc_exit(task, error);
+ dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
+ __func__, error);
+ return ERR_PTR(error);
+out_overflow:
+ dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
+ __func__);
+ goto out_garbage;
+}
+
+static void rpcproc_encode_null(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;
+ msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+ err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
+ put_rpccred(msg.rpc_cred);
+ return err;
+}
+
+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,
+ .rpc_cred = cred,
+ };
+ struct rpc_task_setup task_setup_data = {
+ .rpc_client = clnt,
+ .rpc_xprt = xprt,
+ .rpc_message = &msg,
+ .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
+ .callback_data = data,
+ .flags = flags,
+ };
+
+ 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_cred *cred;
+ 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);
+
+ cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+ task = rpc_call_null_helper(clnt, xprt, cred,
+ RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
+ &rpc_cb_add_xprt_call_ops, data);
+ put_rpccred(cred);
+ if (IS_ERR(task))
+ return PTR_ERR(task);
+ rpc_put_task(task);
+ 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_cred *cred;
+ 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 */
+ cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+ task = rpc_call_null_helper(clnt, xprt, cred,
+ RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
+ NULL, NULL);
+ put_rpccred(cred);
+ 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);
+
+ /* 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;
+ 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();
+ return -EAGAIN;
+ }
+ resvport = xprt->resvport;
+ 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;
+ 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, task->tk_timeout, task->tk_ops,
+ clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
+ task->tk_action, rpc_waitq);
+}
+
+void rpc_show_tasks(struct net *net)
+{
+ struct rpc_clnt *clnt;
+ struct rpc_task *task;
+ int header = 0;
+ struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+ spin_lock(&sn->rpc_client_lock);
+ list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
+ spin_lock(&clnt->cl_lock);
+ list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
+ if (!header) {
+ rpc_show_header();
+ header++;
+ }
+ rpc_show_task(clnt, task);
+ }
+ spin_unlock(&clnt->cl_lock);
+ }
+ spin_unlock(&sn->rpc_client_lock);
+}
+#endif
+
+#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 */