ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/net/sunrpc/svc.c b/marvell/linux/net/sunrpc/svc.c
new file mode 100644
index 0000000..1b82a7b
--- /dev/null
+++ b/marvell/linux/net/sunrpc/svc.c
@@ -0,0 +1,1740 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/net/sunrpc/svc.c
+ *
+ * High-level RPC service routines
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ *
+ * Multiple threads pools and NUMAisation
+ * Copyright (c) 2006 Silicon Graphics, Inc.
+ * by Greg Banks <gnb@melbourne.sgi.com>
+ */
+
+#include <linux/linkage.h>
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/bc_xprt.h>
+
+#include <trace/events/sunrpc.h>
+
+#define RPCDBG_FACILITY RPCDBG_SVCDSP
+
+static void svc_unregister(const struct svc_serv *serv, struct net *net);
+
+#define svc_serv_is_pooled(serv) ((serv)->sv_ops->svo_function)
+
+#define SVC_POOL_DEFAULT SVC_POOL_GLOBAL
+
+/*
+ * Structure for mapping cpus to pools and vice versa.
+ * Setup once during sunrpc initialisation.
+ */
+struct svc_pool_map svc_pool_map = {
+ .mode = SVC_POOL_DEFAULT
+};
+EXPORT_SYMBOL_GPL(svc_pool_map);
+
+static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
+
+static int
+param_set_pool_mode(const char *val, const struct kernel_param *kp)
+{
+ int *ip = (int *)kp->arg;
+ struct svc_pool_map *m = &svc_pool_map;
+ int err;
+
+ mutex_lock(&svc_pool_map_mutex);
+
+ err = -EBUSY;
+ if (m->count)
+ goto out;
+
+ err = 0;
+ if (!strncmp(val, "auto", 4))
+ *ip = SVC_POOL_AUTO;
+ else if (!strncmp(val, "global", 6))
+ *ip = SVC_POOL_GLOBAL;
+ else if (!strncmp(val, "percpu", 6))
+ *ip = SVC_POOL_PERCPU;
+ else if (!strncmp(val, "pernode", 7))
+ *ip = SVC_POOL_PERNODE;
+ else
+ err = -EINVAL;
+
+out:
+ mutex_unlock(&svc_pool_map_mutex);
+ return err;
+}
+
+static int
+param_get_pool_mode(char *buf, const struct kernel_param *kp)
+{
+ int *ip = (int *)kp->arg;
+
+ switch (*ip)
+ {
+ case SVC_POOL_AUTO:
+ return strlcpy(buf, "auto", 20);
+ case SVC_POOL_GLOBAL:
+ return strlcpy(buf, "global", 20);
+ case SVC_POOL_PERCPU:
+ return strlcpy(buf, "percpu", 20);
+ case SVC_POOL_PERNODE:
+ return strlcpy(buf, "pernode", 20);
+ default:
+ return sprintf(buf, "%d", *ip);
+ }
+}
+
+module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
+ &svc_pool_map.mode, 0644);
+
+/*
+ * Detect best pool mapping mode heuristically,
+ * according to the machine's topology.
+ */
+static int
+svc_pool_map_choose_mode(void)
+{
+ unsigned int node;
+
+ if (nr_online_nodes > 1) {
+ /*
+ * Actually have multiple NUMA nodes,
+ * so split pools on NUMA node boundaries
+ */
+ return SVC_POOL_PERNODE;
+ }
+
+ node = first_online_node;
+ if (nr_cpus_node(node) > 2) {
+ /*
+ * Non-trivial SMP, or CONFIG_NUMA on
+ * non-NUMA hardware, e.g. with a generic
+ * x86_64 kernel on Xeons. In this case we
+ * want to divide the pools on cpu boundaries.
+ */
+ return SVC_POOL_PERCPU;
+ }
+
+ /* default: one global pool */
+ return SVC_POOL_GLOBAL;
+}
+
+/*
+ * Allocate the to_pool[] and pool_to[] arrays.
+ * Returns 0 on success or an errno.
+ */
+static int
+svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
+{
+ m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
+ if (!m->to_pool)
+ goto fail;
+ m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
+ if (!m->pool_to)
+ goto fail_free;
+
+ return 0;
+
+fail_free:
+ kfree(m->to_pool);
+ m->to_pool = NULL;
+fail:
+ return -ENOMEM;
+}
+
+/*
+ * Initialise the pool map for SVC_POOL_PERCPU mode.
+ * Returns number of pools or <0 on error.
+ */
+static int
+svc_pool_map_init_percpu(struct svc_pool_map *m)
+{
+ unsigned int maxpools = nr_cpu_ids;
+ unsigned int pidx = 0;
+ unsigned int cpu;
+ int err;
+
+ err = svc_pool_map_alloc_arrays(m, maxpools);
+ if (err)
+ return err;
+
+ for_each_online_cpu(cpu) {
+ BUG_ON(pidx >= maxpools);
+ m->to_pool[cpu] = pidx;
+ m->pool_to[pidx] = cpu;
+ pidx++;
+ }
+ /* cpus brought online later all get mapped to pool0, sorry */
+
+ return pidx;
+};
+
+
+/*
+ * Initialise the pool map for SVC_POOL_PERNODE mode.
+ * Returns number of pools or <0 on error.
+ */
+static int
+svc_pool_map_init_pernode(struct svc_pool_map *m)
+{
+ unsigned int maxpools = nr_node_ids;
+ unsigned int pidx = 0;
+ unsigned int node;
+ int err;
+
+ err = svc_pool_map_alloc_arrays(m, maxpools);
+ if (err)
+ return err;
+
+ for_each_node_with_cpus(node) {
+ /* some architectures (e.g. SN2) have cpuless nodes */
+ BUG_ON(pidx > maxpools);
+ m->to_pool[node] = pidx;
+ m->pool_to[pidx] = node;
+ pidx++;
+ }
+ /* nodes brought online later all get mapped to pool0, sorry */
+
+ return pidx;
+}
+
+
+/*
+ * Add a reference to the global map of cpus to pools (and
+ * vice versa). Initialise the map if we're the first user.
+ * Returns the number of pools.
+ */
+unsigned int
+svc_pool_map_get(void)
+{
+ struct svc_pool_map *m = &svc_pool_map;
+ int npools = -1;
+
+ mutex_lock(&svc_pool_map_mutex);
+
+ if (m->count++) {
+ mutex_unlock(&svc_pool_map_mutex);
+ return m->npools;
+ }
+
+ if (m->mode == SVC_POOL_AUTO)
+ m->mode = svc_pool_map_choose_mode();
+
+ switch (m->mode) {
+ case SVC_POOL_PERCPU:
+ npools = svc_pool_map_init_percpu(m);
+ break;
+ case SVC_POOL_PERNODE:
+ npools = svc_pool_map_init_pernode(m);
+ break;
+ }
+
+ if (npools < 0) {
+ /* default, or memory allocation failure */
+ npools = 1;
+ m->mode = SVC_POOL_GLOBAL;
+ }
+ m->npools = npools;
+
+ mutex_unlock(&svc_pool_map_mutex);
+ return m->npools;
+}
+EXPORT_SYMBOL_GPL(svc_pool_map_get);
+
+/*
+ * Drop a reference to the global map of cpus to pools.
+ * When the last reference is dropped, the map data is
+ * freed; this allows the sysadmin to change the pool
+ * mode using the pool_mode module option without
+ * rebooting or re-loading sunrpc.ko.
+ */
+void
+svc_pool_map_put(void)
+{
+ struct svc_pool_map *m = &svc_pool_map;
+
+ mutex_lock(&svc_pool_map_mutex);
+
+ if (!--m->count) {
+ kfree(m->to_pool);
+ m->to_pool = NULL;
+ kfree(m->pool_to);
+ m->pool_to = NULL;
+ m->npools = 0;
+ }
+
+ mutex_unlock(&svc_pool_map_mutex);
+}
+EXPORT_SYMBOL_GPL(svc_pool_map_put);
+
+static int svc_pool_map_get_node(unsigned int pidx)
+{
+ const struct svc_pool_map *m = &svc_pool_map;
+
+ if (m->count) {
+ if (m->mode == SVC_POOL_PERCPU)
+ return cpu_to_node(m->pool_to[pidx]);
+ if (m->mode == SVC_POOL_PERNODE)
+ return m->pool_to[pidx];
+ }
+ return NUMA_NO_NODE;
+}
+/*
+ * Set the given thread's cpus_allowed mask so that it
+ * will only run on cpus in the given pool.
+ */
+static inline void
+svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
+{
+ struct svc_pool_map *m = &svc_pool_map;
+ unsigned int node = m->pool_to[pidx];
+
+ /*
+ * The caller checks for sv_nrpools > 1, which
+ * implies that we've been initialized.
+ */
+ WARN_ON_ONCE(m->count == 0);
+ if (m->count == 0)
+ return;
+
+ switch (m->mode) {
+ case SVC_POOL_PERCPU:
+ {
+ set_cpus_allowed_ptr(task, cpumask_of(node));
+ break;
+ }
+ case SVC_POOL_PERNODE:
+ {
+ set_cpus_allowed_ptr(task, cpumask_of_node(node));
+ break;
+ }
+ }
+}
+
+/*
+ * Use the mapping mode to choose a pool for a given CPU.
+ * Used when enqueueing an incoming RPC. Always returns
+ * a non-NULL pool pointer.
+ */
+struct svc_pool *
+svc_pool_for_cpu(struct svc_serv *serv, int cpu)
+{
+ struct svc_pool_map *m = &svc_pool_map;
+ unsigned int pidx = 0;
+
+ /*
+ * An uninitialised map happens in a pure client when
+ * lockd is brought up, so silently treat it the
+ * same as SVC_POOL_GLOBAL.
+ */
+ if (svc_serv_is_pooled(serv)) {
+ switch (m->mode) {
+ case SVC_POOL_PERCPU:
+ pidx = m->to_pool[cpu];
+ break;
+ case SVC_POOL_PERNODE:
+ pidx = m->to_pool[cpu_to_node(cpu)];
+ break;
+ }
+ }
+ return &serv->sv_pools[pidx % serv->sv_nrpools];
+}
+
+int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
+{
+ int err;
+
+ err = rpcb_create_local(net);
+ if (err)
+ return err;
+
+ /* Remove any stale portmap registrations */
+ svc_unregister(serv, net);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(svc_rpcb_setup);
+
+void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
+{
+ svc_unregister(serv, net);
+ rpcb_put_local(net);
+}
+EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
+
+static int svc_uses_rpcbind(struct svc_serv *serv)
+{
+ struct svc_program *progp;
+ unsigned int i;
+
+ for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+ for (i = 0; i < progp->pg_nvers; i++) {
+ if (progp->pg_vers[i] == NULL)
+ continue;
+ if (!progp->pg_vers[i]->vs_hidden)
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+int svc_bind(struct svc_serv *serv, struct net *net)
+{
+ if (!svc_uses_rpcbind(serv))
+ return 0;
+ return svc_rpcb_setup(serv, net);
+}
+EXPORT_SYMBOL_GPL(svc_bind);
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+static void
+__svc_init_bc(struct svc_serv *serv)
+{
+ INIT_LIST_HEAD(&serv->sv_cb_list);
+ spin_lock_init(&serv->sv_cb_lock);
+ init_waitqueue_head(&serv->sv_cb_waitq);
+}
+#else
+static void
+__svc_init_bc(struct svc_serv *serv)
+{
+}
+#endif
+
+/*
+ * Create an RPC service
+ */
+static struct svc_serv *
+__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
+ const struct svc_serv_ops *ops)
+{
+ struct svc_serv *serv;
+ unsigned int vers;
+ unsigned int xdrsize;
+ unsigned int i;
+
+ if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
+ return NULL;
+ serv->sv_name = prog->pg_name;
+ serv->sv_program = prog;
+ serv->sv_nrthreads = 1;
+ serv->sv_stats = prog->pg_stats;
+ if (bufsize > RPCSVC_MAXPAYLOAD)
+ bufsize = RPCSVC_MAXPAYLOAD;
+ serv->sv_max_payload = bufsize? bufsize : 4096;
+ serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
+ serv->sv_ops = ops;
+ xdrsize = 0;
+ while (prog) {
+ prog->pg_lovers = prog->pg_nvers-1;
+ for (vers=0; vers<prog->pg_nvers ; vers++)
+ if (prog->pg_vers[vers]) {
+ prog->pg_hivers = vers;
+ if (prog->pg_lovers > vers)
+ prog->pg_lovers = vers;
+ if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
+ xdrsize = prog->pg_vers[vers]->vs_xdrsize;
+ }
+ prog = prog->pg_next;
+ }
+ serv->sv_xdrsize = xdrsize;
+ INIT_LIST_HEAD(&serv->sv_tempsocks);
+ INIT_LIST_HEAD(&serv->sv_permsocks);
+ timer_setup(&serv->sv_temptimer, NULL, 0);
+ spin_lock_init(&serv->sv_lock);
+
+ __svc_init_bc(serv);
+
+ serv->sv_nrpools = npools;
+ serv->sv_pools =
+ kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
+ GFP_KERNEL);
+ if (!serv->sv_pools) {
+ kfree(serv);
+ return NULL;
+ }
+
+ for (i = 0; i < serv->sv_nrpools; i++) {
+ struct svc_pool *pool = &serv->sv_pools[i];
+
+ dprintk("svc: initialising pool %u for %s\n",
+ i, serv->sv_name);
+
+ pool->sp_id = i;
+ INIT_LIST_HEAD(&pool->sp_sockets);
+ INIT_LIST_HEAD(&pool->sp_all_threads);
+ spin_lock_init(&pool->sp_lock);
+ }
+
+ return serv;
+}
+
+struct svc_serv *
+svc_create(struct svc_program *prog, unsigned int bufsize,
+ const struct svc_serv_ops *ops)
+{
+ return __svc_create(prog, bufsize, /*npools*/1, ops);
+}
+EXPORT_SYMBOL_GPL(svc_create);
+
+struct svc_serv *
+svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
+ const struct svc_serv_ops *ops)
+{
+ struct svc_serv *serv;
+ unsigned int npools = svc_pool_map_get();
+
+ serv = __svc_create(prog, bufsize, npools, ops);
+ if (!serv)
+ goto out_err;
+ return serv;
+out_err:
+ svc_pool_map_put();
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(svc_create_pooled);
+
+void svc_shutdown_net(struct svc_serv *serv, struct net *net)
+{
+ svc_close_net(serv, net);
+
+ if (serv->sv_ops->svo_shutdown)
+ serv->sv_ops->svo_shutdown(serv, net);
+}
+EXPORT_SYMBOL_GPL(svc_shutdown_net);
+
+/*
+ * Destroy an RPC service. Should be called with appropriate locking to
+ * protect the sv_nrthreads, sv_permsocks and sv_tempsocks.
+ */
+void
+svc_destroy(struct svc_serv *serv)
+{
+ dprintk("svc: svc_destroy(%s, %d)\n",
+ serv->sv_program->pg_name,
+ serv->sv_nrthreads);
+
+ if (serv->sv_nrthreads) {
+ if (--(serv->sv_nrthreads) != 0) {
+ svc_sock_update_bufs(serv);
+ return;
+ }
+ } else
+ printk("svc_destroy: no threads for serv=%p!\n", serv);
+
+ del_timer_sync(&serv->sv_temptimer);
+
+ /*
+ * The last user is gone and thus all sockets have to be destroyed to
+ * the point. Check this.
+ */
+ BUG_ON(!list_empty(&serv->sv_permsocks));
+ BUG_ON(!list_empty(&serv->sv_tempsocks));
+
+ cache_clean_deferred(serv);
+
+ if (svc_serv_is_pooled(serv))
+ svc_pool_map_put();
+
+ kfree(serv->sv_pools);
+ kfree(serv);
+}
+EXPORT_SYMBOL_GPL(svc_destroy);
+
+/*
+ * Allocate an RPC server's buffer space.
+ * We allocate pages and place them in rq_argpages.
+ */
+static int
+svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
+{
+ unsigned int pages, arghi;
+
+ /* bc_xprt uses fore channel allocated buffers */
+ if (svc_is_backchannel(rqstp))
+ return 1;
+
+ pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
+ * We assume one is at most one page
+ */
+ arghi = 0;
+ WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
+ if (pages > RPCSVC_MAXPAGES)
+ pages = RPCSVC_MAXPAGES;
+ while (pages) {
+ struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
+ if (!p)
+ break;
+ rqstp->rq_pages[arghi++] = p;
+ pages--;
+ }
+ return pages == 0;
+}
+
+/*
+ * Release an RPC server buffer
+ */
+static void
+svc_release_buffer(struct svc_rqst *rqstp)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
+ if (rqstp->rq_pages[i])
+ put_page(rqstp->rq_pages[i]);
+}
+
+struct svc_rqst *
+svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
+{
+ struct svc_rqst *rqstp;
+
+ rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
+ if (!rqstp)
+ return rqstp;
+
+ __set_bit(RQ_BUSY, &rqstp->rq_flags);
+ spin_lock_init(&rqstp->rq_lock);
+ rqstp->rq_server = serv;
+ rqstp->rq_pool = pool;
+
+ rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
+ if (!rqstp->rq_argp)
+ goto out_enomem;
+
+ rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
+ if (!rqstp->rq_resp)
+ goto out_enomem;
+
+ if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
+ goto out_enomem;
+
+ return rqstp;
+out_enomem:
+ svc_rqst_free(rqstp);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(svc_rqst_alloc);
+
+struct svc_rqst *
+svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
+{
+ struct svc_rqst *rqstp;
+
+ rqstp = svc_rqst_alloc(serv, pool, node);
+ if (!rqstp)
+ return ERR_PTR(-ENOMEM);
+
+ serv->sv_nrthreads++;
+ spin_lock_bh(&pool->sp_lock);
+ pool->sp_nrthreads++;
+ list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
+ spin_unlock_bh(&pool->sp_lock);
+ return rqstp;
+}
+EXPORT_SYMBOL_GPL(svc_prepare_thread);
+
+/*
+ * Choose a pool in which to create a new thread, for svc_set_num_threads
+ */
+static inline struct svc_pool *
+choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
+{
+ if (pool != NULL)
+ return pool;
+
+ return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
+}
+
+/*
+ * Choose a thread to kill, for svc_set_num_threads
+ */
+static inline struct task_struct *
+choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
+{
+ unsigned int i;
+ struct task_struct *task = NULL;
+
+ if (pool != NULL) {
+ spin_lock_bh(&pool->sp_lock);
+ } else {
+ /* choose a pool in round-robin fashion */
+ for (i = 0; i < serv->sv_nrpools; i++) {
+ pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
+ spin_lock_bh(&pool->sp_lock);
+ if (!list_empty(&pool->sp_all_threads))
+ goto found_pool;
+ spin_unlock_bh(&pool->sp_lock);
+ }
+ return NULL;
+ }
+
+found_pool:
+ if (!list_empty(&pool->sp_all_threads)) {
+ struct svc_rqst *rqstp;
+
+ /*
+ * Remove from the pool->sp_all_threads list
+ * so we don't try to kill it again.
+ */
+ rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
+ set_bit(RQ_VICTIM, &rqstp->rq_flags);
+ list_del_rcu(&rqstp->rq_all);
+ task = rqstp->rq_task;
+ }
+ spin_unlock_bh(&pool->sp_lock);
+
+ return task;
+}
+
+/* create new threads */
+static int
+svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
+{
+ struct svc_rqst *rqstp;
+ struct task_struct *task;
+ struct svc_pool *chosen_pool;
+ unsigned int state = serv->sv_nrthreads-1;
+ int node;
+
+ do {
+ nrservs--;
+ chosen_pool = choose_pool(serv, pool, &state);
+
+ node = svc_pool_map_get_node(chosen_pool->sp_id);
+ rqstp = svc_prepare_thread(serv, chosen_pool, node);
+ if (IS_ERR(rqstp))
+ return PTR_ERR(rqstp);
+
+ __module_get(serv->sv_ops->svo_module);
+ task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp,
+ node, "%s", serv->sv_name);
+ if (IS_ERR(task)) {
+ module_put(serv->sv_ops->svo_module);
+ svc_exit_thread(rqstp);
+ return PTR_ERR(task);
+ }
+
+ rqstp->rq_task = task;
+ if (serv->sv_nrpools > 1)
+ svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
+
+ svc_sock_update_bufs(serv);
+ wake_up_process(task);
+ } while (nrservs > 0);
+
+ return 0;
+}
+
+
+/* destroy old threads */
+static int
+svc_signal_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
+{
+ struct task_struct *task;
+ unsigned int state = serv->sv_nrthreads-1;
+
+ /* destroy old threads */
+ do {
+ task = choose_victim(serv, pool, &state);
+ if (task == NULL)
+ break;
+ send_sig(SIGINT, task, 1);
+ nrservs++;
+ } while (nrservs < 0);
+
+ return 0;
+}
+
+/*
+ * Create or destroy enough new threads to make the number
+ * of threads the given number. If `pool' is non-NULL, applies
+ * only to threads in that pool, otherwise round-robins between
+ * all pools. Caller must ensure that mutual exclusion between this and
+ * server startup or shutdown.
+ *
+ * Destroying threads relies on the service threads filling in
+ * rqstp->rq_task, which only the nfs ones do. Assumes the serv
+ * has been created using svc_create_pooled().
+ *
+ * Based on code that used to be in nfsd_svc() but tweaked
+ * to be pool-aware.
+ */
+int
+svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
+{
+ if (pool == NULL) {
+ /* The -1 assumes caller has done a svc_get() */
+ nrservs -= (serv->sv_nrthreads-1);
+ } else {
+ spin_lock_bh(&pool->sp_lock);
+ nrservs -= pool->sp_nrthreads;
+ spin_unlock_bh(&pool->sp_lock);
+ }
+
+ if (nrservs > 0)
+ return svc_start_kthreads(serv, pool, nrservs);
+ if (nrservs < 0)
+ return svc_signal_kthreads(serv, pool, nrservs);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(svc_set_num_threads);
+
+/* destroy old threads */
+static int
+svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
+{
+ struct task_struct *task;
+ unsigned int state = serv->sv_nrthreads-1;
+
+ /* destroy old threads */
+ do {
+ task = choose_victim(serv, pool, &state);
+ if (task == NULL)
+ break;
+ kthread_stop(task);
+ nrservs++;
+ } while (nrservs < 0);
+ return 0;
+}
+
+int
+svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
+{
+ if (pool == NULL) {
+ /* The -1 assumes caller has done a svc_get() */
+ nrservs -= (serv->sv_nrthreads-1);
+ } else {
+ spin_lock_bh(&pool->sp_lock);
+ nrservs -= pool->sp_nrthreads;
+ spin_unlock_bh(&pool->sp_lock);
+ }
+
+ if (nrservs > 0)
+ return svc_start_kthreads(serv, pool, nrservs);
+ if (nrservs < 0)
+ return svc_stop_kthreads(serv, pool, nrservs);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(svc_set_num_threads_sync);
+
+/*
+ * Called from a server thread as it's exiting. Caller must hold the "service
+ * mutex" for the service.
+ */
+void
+svc_rqst_free(struct svc_rqst *rqstp)
+{
+ svc_release_buffer(rqstp);
+ kfree(rqstp->rq_resp);
+ kfree(rqstp->rq_argp);
+ kfree(rqstp->rq_auth_data);
+ kfree_rcu(rqstp, rq_rcu_head);
+}
+EXPORT_SYMBOL_GPL(svc_rqst_free);
+
+void
+svc_exit_thread(struct svc_rqst *rqstp)
+{
+ struct svc_serv *serv = rqstp->rq_server;
+ struct svc_pool *pool = rqstp->rq_pool;
+
+ spin_lock_bh(&pool->sp_lock);
+ pool->sp_nrthreads--;
+ if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
+ list_del_rcu(&rqstp->rq_all);
+ spin_unlock_bh(&pool->sp_lock);
+
+ svc_rqst_free(rqstp);
+
+ /* Release the server */
+ if (serv)
+ svc_destroy(serv);
+}
+EXPORT_SYMBOL_GPL(svc_exit_thread);
+
+/*
+ * Register an "inet" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
+ *
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_rpcb_register4(struct net *net, const u32 program,
+ const u32 version,
+ const unsigned short protocol,
+ const unsigned short port)
+{
+ const struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_ANY),
+ .sin_port = htons(port),
+ };
+ const char *netid;
+ int error;
+
+ switch (protocol) {
+ case IPPROTO_UDP:
+ netid = RPCBIND_NETID_UDP;
+ break;
+ case IPPROTO_TCP:
+ netid = RPCBIND_NETID_TCP;
+ break;
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ error = rpcb_v4_register(net, program, version,
+ (const struct sockaddr *)&sin, netid);
+
+ /*
+ * User space didn't support rpcbind v4, so retry this
+ * registration request with the legacy rpcbind v2 protocol.
+ */
+ if (error == -EPROTONOSUPPORT)
+ error = rpcb_register(net, program, version, protocol, port);
+
+ return error;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/*
+ * Register an "inet6" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
+ *
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_rpcb_register6(struct net *net, const u32 program,
+ const u32 version,
+ const unsigned short protocol,
+ const unsigned short port)
+{
+ const struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_addr = IN6ADDR_ANY_INIT,
+ .sin6_port = htons(port),
+ };
+ const char *netid;
+ int error;
+
+ switch (protocol) {
+ case IPPROTO_UDP:
+ netid = RPCBIND_NETID_UDP6;
+ break;
+ case IPPROTO_TCP:
+ netid = RPCBIND_NETID_TCP6;
+ break;
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ error = rpcb_v4_register(net, program, version,
+ (const struct sockaddr *)&sin6, netid);
+
+ /*
+ * User space didn't support rpcbind version 4, so we won't
+ * use a PF_INET6 listener.
+ */
+ if (error == -EPROTONOSUPPORT)
+ error = -EAFNOSUPPORT;
+
+ return error;
+}
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+
+/*
+ * Register a kernel RPC service via rpcbind version 4.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_register(struct net *net, const char *progname,
+ const u32 program, const u32 version,
+ const int family,
+ const unsigned short protocol,
+ const unsigned short port)
+{
+ int error = -EAFNOSUPPORT;
+
+ switch (family) {
+ case PF_INET:
+ error = __svc_rpcb_register4(net, program, version,
+ protocol, port);
+ break;
+#if IS_ENABLED(CONFIG_IPV6)
+ case PF_INET6:
+ error = __svc_rpcb_register6(net, program, version,
+ protocol, port);
+#endif
+ }
+
+ return error;
+}
+
+int svc_rpcbind_set_version(struct net *net,
+ const struct svc_program *progp,
+ u32 version, int family,
+ unsigned short proto,
+ unsigned short port)
+{
+ dprintk("svc: svc_register(%sv%d, %s, %u, %u)\n",
+ progp->pg_name, version,
+ proto == IPPROTO_UDP? "udp" : "tcp",
+ port, family);
+
+ return __svc_register(net, progp->pg_name, progp->pg_prog,
+ version, family, proto, port);
+
+}
+EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
+
+int svc_generic_rpcbind_set(struct net *net,
+ const struct svc_program *progp,
+ u32 version, int family,
+ unsigned short proto,
+ unsigned short port)
+{
+ const struct svc_version *vers = progp->pg_vers[version];
+ int error;
+
+ if (vers == NULL)
+ return 0;
+
+ if (vers->vs_hidden) {
+ dprintk("svc: svc_register(%sv%d, %s, %u, %u)"
+ " (but not telling portmap)\n",
+ progp->pg_name, version,
+ proto == IPPROTO_UDP? "udp" : "tcp",
+ port, family);
+ return 0;
+ }
+
+ /*
+ * Don't register a UDP port if we need congestion
+ * control.
+ */
+ if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
+ return 0;
+
+ error = svc_rpcbind_set_version(net, progp, version,
+ family, proto, port);
+
+ return (vers->vs_rpcb_optnl) ? 0 : error;
+}
+EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
+
+/**
+ * svc_register - register an RPC service with the local portmapper
+ * @serv: svc_serv struct for the service to register
+ * @net: net namespace for the service to register
+ * @family: protocol family of service's listener socket
+ * @proto: transport protocol number to advertise
+ * @port: port to advertise
+ *
+ * Service is registered for any address in the passed-in protocol family
+ */
+int svc_register(const struct svc_serv *serv, struct net *net,
+ const int family, const unsigned short proto,
+ const unsigned short port)
+{
+ struct svc_program *progp;
+ unsigned int i;
+ int error = 0;
+
+ WARN_ON_ONCE(proto == 0 && port == 0);
+ if (proto == 0 && port == 0)
+ return -EINVAL;
+
+ for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+ for (i = 0; i < progp->pg_nvers; i++) {
+
+ error = progp->pg_rpcbind_set(net, progp, i,
+ family, proto, port);
+ if (error < 0) {
+ printk(KERN_WARNING "svc: failed to register "
+ "%sv%u RPC service (errno %d).\n",
+ progp->pg_name, i, -error);
+ break;
+ }
+ }
+ }
+
+ return error;
+}
+
+/*
+ * If user space is running rpcbind, it should take the v4 UNSET
+ * and clear everything for this [program, version]. If user space
+ * is running portmap, it will reject the v4 UNSET, but won't have
+ * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient
+ * in this case to clear all existing entries for [program, version].
+ */
+static void __svc_unregister(struct net *net, const u32 program, const u32 version,
+ const char *progname)
+{
+ int error;
+
+ error = rpcb_v4_register(net, program, version, NULL, "");
+
+ /*
+ * User space didn't support rpcbind v4, so retry this
+ * request with the legacy rpcbind v2 protocol.
+ */
+ if (error == -EPROTONOSUPPORT)
+ error = rpcb_register(net, program, version, 0, 0);
+
+ dprintk("svc: %s(%sv%u), error %d\n",
+ __func__, progname, version, error);
+}
+
+/*
+ * All netids, bind addresses and ports registered for [program, version]
+ * are removed from the local rpcbind database (if the service is not
+ * hidden) to make way for a new instance of the service.
+ *
+ * The result of unregistration is reported via dprintk for those who want
+ * verification of the result, but is otherwise not important.
+ */
+static void svc_unregister(const struct svc_serv *serv, struct net *net)
+{
+ struct svc_program *progp;
+ unsigned long flags;
+ unsigned int i;
+
+ clear_thread_flag(TIF_SIGPENDING);
+
+ for (progp = serv->sv_program; progp; progp = progp->pg_next) {
+ for (i = 0; i < progp->pg_nvers; i++) {
+ if (progp->pg_vers[i] == NULL)
+ continue;
+ if (progp->pg_vers[i]->vs_hidden)
+ continue;
+
+ dprintk("svc: attempting to unregister %sv%u\n",
+ progp->pg_name, i);
+ __svc_unregister(net, progp->pg_prog, i, progp->pg_name);
+ }
+ }
+
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ recalc_sigpending();
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
+}
+
+/*
+ * dprintk the given error with the address of the client that caused it.
+ */
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+static __printf(2, 3)
+void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+ char buf[RPC_MAX_ADDRBUFLEN];
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
+
+ va_end(args);
+}
+#else
+static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
+#endif
+
+__be32
+svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err)
+{
+ set_bit(RQ_AUTHERR, &rqstp->rq_flags);
+ return auth_err;
+}
+EXPORT_SYMBOL_GPL(svc_return_autherr);
+
+static __be32
+svc_get_autherr(struct svc_rqst *rqstp, __be32 *statp)
+{
+ if (test_and_clear_bit(RQ_AUTHERR, &rqstp->rq_flags))
+ return *statp;
+ return rpc_auth_ok;
+}
+
+static int
+svc_generic_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+{
+ struct kvec *argv = &rqstp->rq_arg.head[0];
+ struct kvec *resv = &rqstp->rq_res.head[0];
+ const struct svc_procedure *procp = rqstp->rq_procinfo;
+
+ /*
+ * Decode arguments
+ * XXX: why do we ignore the return value?
+ */
+ if (procp->pc_decode &&
+ !procp->pc_decode(rqstp, argv->iov_base)) {
+ *statp = rpc_garbage_args;
+ return 1;
+ }
+
+ *statp = procp->pc_func(rqstp);
+
+ if (*statp == rpc_drop_reply ||
+ test_bit(RQ_DROPME, &rqstp->rq_flags))
+ return 0;
+
+ if (test_bit(RQ_AUTHERR, &rqstp->rq_flags))
+ return 1;
+
+ if (*statp != rpc_success)
+ return 1;
+
+ /* Encode reply */
+ if (procp->pc_encode &&
+ !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) {
+ dprintk("svc: failed to encode reply\n");
+ /* serv->sv_stats->rpcsystemerr++; */
+ *statp = rpc_system_err;
+ }
+ return 1;
+}
+
+__be32
+svc_generic_init_request(struct svc_rqst *rqstp,
+ const struct svc_program *progp,
+ struct svc_process_info *ret)
+{
+ const struct svc_version *versp = NULL; /* compiler food */
+ const struct svc_procedure *procp = NULL;
+
+ if (rqstp->rq_vers >= progp->pg_nvers )
+ goto err_bad_vers;
+ versp = progp->pg_vers[rqstp->rq_vers];
+ if (!versp)
+ goto err_bad_vers;
+
+ /*
+ * Some protocol versions (namely NFSv4) require some form of
+ * congestion control. (See RFC 7530 section 3.1 paragraph 2)
+ * In other words, UDP is not allowed. We mark those when setting
+ * up the svc_xprt, and verify that here.
+ *
+ * The spec is not very clear about what error should be returned
+ * when someone tries to access a server that is listening on UDP
+ * for lower versions. RPC_PROG_MISMATCH seems to be the closest
+ * fit.
+ */
+ if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
+ !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
+ goto err_bad_vers;
+
+ if (rqstp->rq_proc >= versp->vs_nproc)
+ goto err_bad_proc;
+ rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
+
+ /* Initialize storage for argp and resp */
+ memset(rqstp->rq_argp, 0, procp->pc_argsize);
+ memset(rqstp->rq_resp, 0, procp->pc_ressize);
+
+ /* Bump per-procedure stats counter */
+ versp->vs_count[rqstp->rq_proc]++;
+
+ ret->dispatch = versp->vs_dispatch;
+ return rpc_success;
+err_bad_vers:
+ ret->mismatch.lovers = progp->pg_lovers;
+ ret->mismatch.hivers = progp->pg_hivers;
+ return rpc_prog_mismatch;
+err_bad_proc:
+ return rpc_proc_unavail;
+}
+EXPORT_SYMBOL_GPL(svc_generic_init_request);
+
+/*
+ * Common routine for processing the RPC request.
+ */
+static int
+svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
+{
+ struct svc_program *progp;
+ const struct svc_procedure *procp = NULL;
+ struct svc_serv *serv = rqstp->rq_server;
+ struct svc_process_info process;
+ __be32 *statp;
+ u32 prog, vers;
+ __be32 auth_stat, rpc_stat;
+ int auth_res;
+ __be32 *reply_statp;
+
+ rpc_stat = rpc_success;
+
+ if (argv->iov_len < 6*4)
+ goto err_short_len;
+
+ /* Will be turned off by GSS integrity and privacy services */
+ set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+ /* Will be turned off only when NFSv4 Sessions are used */
+ set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+ clear_bit(RQ_DROPME, &rqstp->rq_flags);
+
+ svc_putu32(resv, rqstp->rq_xid);
+
+ vers = svc_getnl(argv);
+
+ /* First words of reply: */
+ svc_putnl(resv, 1); /* REPLY */
+
+ if (vers != 2) /* RPC version number */
+ goto err_bad_rpc;
+
+ /* Save position in case we later decide to reject: */
+ reply_statp = resv->iov_base + resv->iov_len;
+
+ svc_putnl(resv, 0); /* ACCEPT */
+
+ rqstp->rq_prog = prog = svc_getnl(argv); /* program number */
+ rqstp->rq_vers = svc_getnl(argv); /* version number */
+ rqstp->rq_proc = svc_getnl(argv); /* procedure number */
+
+ for (progp = serv->sv_program; progp; progp = progp->pg_next)
+ if (prog == progp->pg_prog)
+ break;
+
+ /*
+ * Decode auth data, and add verifier to reply buffer.
+ * We do this before anything else in order to get a decent
+ * auth verifier.
+ */
+ auth_res = svc_authenticate(rqstp, &auth_stat);
+ /* Also give the program a chance to reject this call: */
+ if (auth_res == SVC_OK && progp) {
+ auth_stat = rpc_autherr_badcred;
+ auth_res = progp->pg_authenticate(rqstp);
+ }
+ switch (auth_res) {
+ case SVC_OK:
+ break;
+ case SVC_GARBAGE:
+ goto err_garbage;
+ case SVC_SYSERR:
+ rpc_stat = rpc_system_err;
+ goto err_bad;
+ case SVC_DENIED:
+ goto err_bad_auth;
+ case SVC_CLOSE:
+ goto close;
+ case SVC_DROP:
+ goto dropit;
+ case SVC_COMPLETE:
+ goto sendit;
+ }
+
+ if (progp == NULL)
+ goto err_bad_prog;
+
+ rpc_stat = progp->pg_init_request(rqstp, progp, &process);
+ switch (rpc_stat) {
+ case rpc_success:
+ break;
+ case rpc_prog_unavail:
+ goto err_bad_prog;
+ case rpc_prog_mismatch:
+ goto err_bad_vers;
+ case rpc_proc_unavail:
+ goto err_bad_proc;
+ }
+
+ procp = rqstp->rq_procinfo;
+ /* Should this check go into the dispatcher? */
+ if (!procp || !procp->pc_func)
+ goto err_bad_proc;
+
+ /* Syntactic check complete */
+ serv->sv_stats->rpccnt++;
+ trace_svc_process(rqstp, progp->pg_name);
+
+ /* Build the reply header. */
+ statp = resv->iov_base +resv->iov_len;
+ svc_putnl(resv, RPC_SUCCESS);
+
+ /* un-reserve some of the out-queue now that we have a
+ * better idea of reply size
+ */
+ if (procp->pc_xdrressize)
+ svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
+
+ /* Call the function that processes the request. */
+ if (!process.dispatch) {
+ if (!svc_generic_dispatch(rqstp, statp))
+ goto release_dropit;
+ if (*statp == rpc_garbage_args)
+ goto err_garbage;
+ auth_stat = svc_get_autherr(rqstp, statp);
+ if (auth_stat != rpc_auth_ok)
+ goto err_release_bad_auth;
+ } else {
+ dprintk("svc: calling dispatcher\n");
+ if (!process.dispatch(rqstp, statp))
+ goto release_dropit; /* Release reply info */
+ }
+
+ /* Check RPC status result */
+ if (*statp != rpc_success)
+ resv->iov_len = ((void*)statp) - resv->iov_base + 4;
+
+ /* Release reply info */
+ if (procp->pc_release)
+ procp->pc_release(rqstp);
+
+ if (procp->pc_encode == NULL)
+ goto dropit;
+
+ sendit:
+ if (svc_authorise(rqstp))
+ goto close_xprt;
+ return 1; /* Caller can now send it */
+
+release_dropit:
+ if (procp->pc_release)
+ procp->pc_release(rqstp);
+ dropit:
+ svc_authorise(rqstp); /* doesn't hurt to call this twice */
+ dprintk("svc: svc_process dropit\n");
+ return 0;
+
+ close:
+ svc_authorise(rqstp);
+close_xprt:
+ if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
+ svc_close_xprt(rqstp->rq_xprt);
+ dprintk("svc: svc_process close\n");
+ return 0;
+
+err_short_len:
+ svc_printk(rqstp, "short len %zd, dropping request\n",
+ argv->iov_len);
+ goto close_xprt;
+
+err_bad_rpc:
+ serv->sv_stats->rpcbadfmt++;
+ svc_putnl(resv, 1); /* REJECT */
+ svc_putnl(resv, 0); /* RPC_MISMATCH */
+ svc_putnl(resv, 2); /* Only RPCv2 supported */
+ svc_putnl(resv, 2);
+ goto sendit;
+
+err_release_bad_auth:
+ if (procp->pc_release)
+ procp->pc_release(rqstp);
+err_bad_auth:
+ dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
+ serv->sv_stats->rpcbadauth++;
+ /* Restore write pointer to location of accept status: */
+ xdr_ressize_check(rqstp, reply_statp);
+ svc_putnl(resv, 1); /* REJECT */
+ svc_putnl(resv, 1); /* AUTH_ERROR */
+ svc_putnl(resv, ntohl(auth_stat)); /* status */
+ goto sendit;
+
+err_bad_prog:
+ dprintk("svc: unknown program %d\n", prog);
+ serv->sv_stats->rpcbadfmt++;
+ svc_putnl(resv, RPC_PROG_UNAVAIL);
+ goto sendit;
+
+err_bad_vers:
+ svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
+ rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
+
+ serv->sv_stats->rpcbadfmt++;
+ svc_putnl(resv, RPC_PROG_MISMATCH);
+ svc_putnl(resv, process.mismatch.lovers);
+ svc_putnl(resv, process.mismatch.hivers);
+ goto sendit;
+
+err_bad_proc:
+ svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
+
+ serv->sv_stats->rpcbadfmt++;
+ svc_putnl(resv, RPC_PROC_UNAVAIL);
+ goto sendit;
+
+err_garbage:
+ svc_printk(rqstp, "failed to decode args\n");
+
+ rpc_stat = rpc_garbage_args;
+err_bad:
+ serv->sv_stats->rpcbadfmt++;
+ svc_putnl(resv, ntohl(rpc_stat));
+ goto sendit;
+}
+
+/*
+ * Process the RPC request.
+ */
+int
+svc_process(struct svc_rqst *rqstp)
+{
+ struct kvec *argv = &rqstp->rq_arg.head[0];
+ struct kvec *resv = &rqstp->rq_res.head[0];
+ struct svc_serv *serv = rqstp->rq_server;
+ u32 dir;
+
+ /*
+ * Setup response xdr_buf.
+ * Initially it has just one page
+ */
+ rqstp->rq_next_page = &rqstp->rq_respages[1];
+ resv->iov_base = page_address(rqstp->rq_respages[0]);
+ resv->iov_len = 0;
+ rqstp->rq_res.pages = rqstp->rq_respages + 1;
+ rqstp->rq_res.len = 0;
+ rqstp->rq_res.page_base = 0;
+ rqstp->rq_res.page_len = 0;
+ rqstp->rq_res.buflen = PAGE_SIZE;
+ rqstp->rq_res.tail[0].iov_base = NULL;
+ rqstp->rq_res.tail[0].iov_len = 0;
+
+ dir = svc_getnl(argv);
+ if (dir != 0) {
+ /* direction != CALL */
+ svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
+ serv->sv_stats->rpcbadfmt++;
+ goto out_drop;
+ }
+
+ /* Reserve space for the record marker */
+ if (rqstp->rq_prot == IPPROTO_TCP)
+ svc_putnl(resv, 0);
+
+ /* Returns 1 for send, 0 for drop */
+ if (likely(svc_process_common(rqstp, argv, resv)))
+ return svc_send(rqstp);
+
+out_drop:
+ svc_drop(rqstp);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(svc_process);
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+/*
+ * Process a backchannel RPC request that arrived over an existing
+ * outbound connection
+ */
+int
+bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
+ struct svc_rqst *rqstp)
+{
+ struct kvec *argv = &rqstp->rq_arg.head[0];
+ struct kvec *resv = &rqstp->rq_res.head[0];
+ struct rpc_task *task;
+ int proc_error;
+ int error;
+
+ dprintk("svc: %s(%p)\n", __func__, req);
+
+ /* Build the svc_rqst used by the common processing routine */
+ rqstp->rq_xid = req->rq_xid;
+ rqstp->rq_prot = req->rq_xprt->prot;
+ rqstp->rq_server = serv;
+ rqstp->rq_bc_net = req->rq_xprt->xprt_net;
+
+ rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
+ memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
+ memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
+ memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
+
+ /* Adjust the argument buffer length */
+ rqstp->rq_arg.len = req->rq_private_buf.len;
+ if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
+ rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
+ rqstp->rq_arg.page_len = 0;
+ } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
+ rqstp->rq_arg.page_len)
+ rqstp->rq_arg.page_len = rqstp->rq_arg.len -
+ rqstp->rq_arg.head[0].iov_len;
+ else
+ rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
+ rqstp->rq_arg.page_len;
+
+ /* reset result send buffer "put" position */
+ resv->iov_len = 0;
+
+ /*
+ * Skip the next two words because they've already been
+ * processed in the transport
+ */
+ svc_getu32(argv); /* XID */
+ svc_getnl(argv); /* CALLDIR */
+
+ /* Parse and execute the bc call */
+ proc_error = svc_process_common(rqstp, argv, resv);
+
+ atomic_dec(&req->rq_xprt->bc_slot_count);
+ if (!proc_error) {
+ /* Processing error: drop the request */
+ xprt_free_bc_request(req);
+ error = -EINVAL;
+ goto out;
+ }
+ /* Finally, send the reply synchronously */
+ memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
+ task = rpc_run_bc_task(req);
+ if (IS_ERR(task)) {
+ error = PTR_ERR(task);
+ goto out;
+ }
+
+ WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
+ error = task->tk_status;
+ rpc_put_task(task);
+
+out:
+ dprintk("svc: %s(), error=%d\n", __func__, error);
+ return error;
+}
+EXPORT_SYMBOL_GPL(bc_svc_process);
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+/*
+ * Return (transport-specific) limit on the rpc payload.
+ */
+u32 svc_max_payload(const struct svc_rqst *rqstp)
+{
+ u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
+
+ if (rqstp->rq_server->sv_max_payload < max)
+ max = rqstp->rq_server->sv_max_payload;
+ return max;
+}
+EXPORT_SYMBOL_GPL(svc_max_payload);
+
+/**
+ * svc_encode_read_payload - mark a range of bytes as a READ payload
+ * @rqstp: svc_rqst to operate on
+ * @offset: payload's byte offset in rqstp->rq_res
+ * @length: size of payload, in bytes
+ *
+ * Returns zero on success, or a negative errno if a permanent
+ * error occurred.
+ */
+int svc_encode_read_payload(struct svc_rqst *rqstp, unsigned int offset,
+ unsigned int length)
+{
+ return rqstp->rq_xprt->xpt_ops->xpo_read_payload(rqstp, offset, length);
+}
+EXPORT_SYMBOL_GPL(svc_encode_read_payload);
+
+/**
+ * svc_fill_write_vector - Construct data argument for VFS write call
+ * @rqstp: svc_rqst to operate on
+ * @pages: list of pages containing data payload
+ * @first: buffer containing first section of write payload
+ * @total: total number of bytes of write payload
+ *
+ * Fills in rqstp::rq_vec, and returns the number of elements.
+ */
+unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct page **pages,
+ struct kvec *first, size_t total)
+{
+ struct kvec *vec = rqstp->rq_vec;
+ unsigned int i;
+
+ /* Some types of transport can present the write payload
+ * entirely in rq_arg.pages. In this case, @first is empty.
+ */
+ i = 0;
+ if (first->iov_len) {
+ vec[i].iov_base = first->iov_base;
+ vec[i].iov_len = min_t(size_t, total, first->iov_len);
+ total -= vec[i].iov_len;
+ ++i;
+ }
+
+ while (total) {
+ vec[i].iov_base = page_address(*pages);
+ vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
+ total -= vec[i].iov_len;
+ ++i;
+ ++pages;
+ }
+
+ WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
+ return i;
+}
+EXPORT_SYMBOL_GPL(svc_fill_write_vector);
+
+/**
+ * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
+ * @rqstp: svc_rqst to operate on
+ * @first: buffer containing first section of pathname
+ * @p: buffer containing remaining section of pathname
+ * @total: total length of the pathname argument
+ *
+ * The VFS symlink API demands a NUL-terminated pathname in mapped memory.
+ * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free
+ * the returned string.
+ */
+char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
+ void *p, size_t total)
+{
+ size_t len, remaining;
+ char *result, *dst;
+
+ result = kmalloc(total + 1, GFP_KERNEL);
+ if (!result)
+ return ERR_PTR(-ESERVERFAULT);
+
+ dst = result;
+ remaining = total;
+
+ len = min_t(size_t, total, first->iov_len);
+ if (len) {
+ memcpy(dst, first->iov_base, len);
+ dst += len;
+ remaining -= len;
+ }
+
+ if (remaining) {
+ len = min_t(size_t, remaining, PAGE_SIZE);
+ memcpy(dst, p, len);
+ dst += len;
+ }
+
+ *dst = '\0';
+
+ /* Sanity check: Linux doesn't allow the pathname argument to
+ * contain a NUL byte.
+ */
+ if (strlen(result) != total) {
+ kfree(result);
+ return ERR_PTR(-EINVAL);
+ }
+ return result;
+}
+EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);