// SPDX-License-Identifier: GPL-2.0-only /* * linux/net/sunrpc/svc.c * * High-level RPC service routines * * Copyright (C) 1995, 1996 Olaf Kirch * * Multiple threads pools and NUMAisation * Copyright (c) 2006 Silicon Graphics, Inc. * by Greg Banks */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fail.h" #include "sunrpc.h" #define RPCDBG_FACILITY RPCDBG_SVCDSP static void svc_unregister(const struct svc_serv *serv, struct net *net); #define SVC_POOL_DEFAULT SVC_POOL_GLOBAL /* * Mode for mapping cpus to pools. */ enum { SVC_POOL_AUTO = -1, /* choose one of the others */ SVC_POOL_GLOBAL, /* no mapping, just a single global pool * (legacy & UP mode) */ SVC_POOL_PERCPU, /* one pool per cpu */ SVC_POOL_PERNODE /* one pool per numa node */ }; /* * Structure for mapping cpus to pools and vice versa. * Setup once during sunrpc initialisation. */ struct svc_pool_map { int count; /* How many svc_servs use us */ int mode; /* Note: int not enum to avoid * warnings about "enumeration value * not handled in switch" */ unsigned int npools; unsigned int *pool_to; /* maps pool id to cpu or node */ unsigned int *to_pool; /* maps cpu or node to pool id */ }; static struct svc_pool_map svc_pool_map = { .mode = SVC_POOL_DEFAULT }; static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */ static int __param_set_pool_mode(const char *val, struct svc_pool_map *m) { int err, mode; mutex_lock(&svc_pool_map_mutex); err = 0; if (!strncmp(val, "auto", 4)) mode = SVC_POOL_AUTO; else if (!strncmp(val, "global", 6)) mode = SVC_POOL_GLOBAL; else if (!strncmp(val, "percpu", 6)) mode = SVC_POOL_PERCPU; else if (!strncmp(val, "pernode", 7)) mode = SVC_POOL_PERNODE; else err = -EINVAL; if (err) goto out; if (m->count == 0) m->mode = mode; else if (mode != m->mode) err = -EBUSY; out: mutex_unlock(&svc_pool_map_mutex); return err; } static int param_set_pool_mode(const char *val, const struct kernel_param *kp) { struct svc_pool_map *m = kp->arg; return __param_set_pool_mode(val, m); } int sunrpc_set_pool_mode(const char *val) { return __param_set_pool_mode(val, &svc_pool_map); } EXPORT_SYMBOL(sunrpc_set_pool_mode); /** * sunrpc_get_pool_mode - get the current pool_mode for the host * @buf: where to write the current pool_mode * @size: size of @buf * * Grab the current pool_mode from the svc_pool_map and write * the resulting string to @buf. Returns the number of characters * written to @buf (a'la snprintf()). */ int sunrpc_get_pool_mode(char *buf, size_t size) { struct svc_pool_map *m = &svc_pool_map; switch (m->mode) { case SVC_POOL_AUTO: return snprintf(buf, size, "auto"); case SVC_POOL_GLOBAL: return snprintf(buf, size, "global"); case SVC_POOL_PERCPU: return snprintf(buf, size, "percpu"); case SVC_POOL_PERNODE: return snprintf(buf, size, "pernode"); default: return snprintf(buf, size, "%d", m->mode); } } EXPORT_SYMBOL(sunrpc_get_pool_mode); static int param_get_pool_mode(char *buf, const struct kernel_param *kp) { char str[16]; int len; len = sunrpc_get_pool_mode(str, ARRAY_SIZE(str)); /* Ensure we have room for newline and NUL */ len = min_t(int, len, ARRAY_SIZE(str) - 2); /* tack on the newline */ str[len] = '\n'; str[len + 1] = '\0'; return sysfs_emit(buf, "%s", str); } module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode, &svc_pool_map, 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) if pools are in use. * Initialise the map if we're the first user. * Returns the number of pools. If this is '1', no reference * was taken. */ static 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 npools; } /* * 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. */ static 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); } 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; } } } /** * svc_pool_for_cpu - Select pool to run a thread on this cpu * @serv: An RPC service * * Use the active CPU and the svc_pool_map's mode setting to * select the svc thread pool to use. Once initialized, the * svc_pool_map does not change. * * Return value: * A pointer to an svc_pool */ struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv) { struct svc_pool_map *m = &svc_pool_map; int cpu = raw_smp_processor_id(); unsigned int pidx = 0; if (serv->sv_nrpools <= 1) return serv->sv_pools; 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]; } static 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; } 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) { unsigned int p, i; for (p = 0; p < serv->sv_nprogs; p++) { struct svc_program *progp = &serv->sv_programs[p]; 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) { lwq_init(&serv->sv_cb_list); } #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, int nprogs, struct svc_stat *stats, unsigned int bufsize, int npools, int (*threadfn)(void *data)) { 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_programs = prog; serv->sv_nprogs = nprogs; serv->sv_stats = 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_threadfn = threadfn; xdrsize = 0; for (i = 0; i < nprogs; i++) { struct svc_program *progp = &prog[i]; progp->pg_lovers = progp->pg_nvers-1; for (vers = 0; vers < progp->pg_nvers ; vers++) if (progp->pg_vers[vers]) { progp->pg_hivers = vers; if (progp->pg_lovers > vers) progp->pg_lovers = vers; if (progp->pg_vers[vers]->vs_xdrsize > xdrsize) xdrsize = progp->pg_vers[vers]->vs_xdrsize; } } 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; lwq_init(&pool->sp_xprts); INIT_LIST_HEAD(&pool->sp_all_threads); init_llist_head(&pool->sp_idle_threads); percpu_counter_init(&pool->sp_messages_arrived, 0, GFP_KERNEL); percpu_counter_init(&pool->sp_sockets_queued, 0, GFP_KERNEL); percpu_counter_init(&pool->sp_threads_woken, 0, GFP_KERNEL); } return serv; } /** * svc_create - Create an RPC service * @prog: the RPC program the new service will handle * @bufsize: maximum message size for @prog * @threadfn: a function to service RPC requests for @prog * * Returns an instantiated struct svc_serv object or NULL. */ struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize, int (*threadfn)(void *data)) { return __svc_create(prog, 1, NULL, bufsize, 1, threadfn); } EXPORT_SYMBOL_GPL(svc_create); /** * svc_create_pooled - Create an RPC service with pooled threads * @prog: Array of RPC programs the new service will handle * @nprogs: Number of programs in the array * @stats: the stats struct if desired * @bufsize: maximum message size for @prog * @threadfn: a function to service RPC requests for @prog * * Returns an instantiated struct svc_serv object or NULL. */ struct svc_serv *svc_create_pooled(struct svc_program *prog, unsigned int nprogs, struct svc_stat *stats, unsigned int bufsize, int (*threadfn)(void *data)) { struct svc_serv *serv; unsigned int npools = svc_pool_map_get(); serv = __svc_create(prog, nprogs, stats, bufsize, npools, threadfn); if (!serv) goto out_err; serv->sv_is_pooled = true; return serv; out_err: svc_pool_map_put(); return NULL; } EXPORT_SYMBOL_GPL(svc_create_pooled); /* * Destroy an RPC service. Should be called with appropriate locking to * protect sv_permsocks and sv_tempsocks. */ void svc_destroy(struct svc_serv **servp) { struct svc_serv *serv = *servp; unsigned int i; *servp = NULL; dprintk("svc: svc_destroy(%s)\n", serv->sv_programs->pg_name); timer_shutdown_sync(&serv->sv_temptimer); /* * Remaining transports at this point are not expected. */ WARN_ONCE(!list_empty(&serv->sv_permsocks), "SVC: permsocks remain for %s\n", serv->sv_programs->pg_name); WARN_ONCE(!list_empty(&serv->sv_tempsocks), "SVC: tempsocks remain for %s\n", serv->sv_programs->pg_name); cache_clean_deferred(serv); if (serv->sv_is_pooled) svc_pool_map_put(); for (i = 0; i < serv->sv_nrpools; i++) { struct svc_pool *pool = &serv->sv_pools[i]; percpu_counter_destroy(&pool->sp_messages_arrived); percpu_counter_destroy(&pool->sp_sockets_queued); percpu_counter_destroy(&pool->sp_threads_woken); } kfree(serv->sv_pools); kfree(serv); } EXPORT_SYMBOL_GPL(svc_destroy); static bool svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node) { unsigned long pages, ret; /* bc_xprt uses fore channel allocated buffers */ if (svc_is_backchannel(rqstp)) return true; pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply. * We assume one is at most one page */ WARN_ON_ONCE(pages > RPCSVC_MAXPAGES); if (pages > RPCSVC_MAXPAGES) pages = RPCSVC_MAXPAGES; ret = alloc_pages_bulk_array_node(GFP_KERNEL, node, pages, rqstp->rq_pages); return ret == pages; } /* * 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]); } static void svc_rqst_free(struct svc_rqst *rqstp) { folio_batch_release(&rqstp->rq_fbatch); svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) put_page(rqstp->rq_scratch_page); kfree(rqstp->rq_resp); kfree(rqstp->rq_argp); kfree(rqstp->rq_auth_data); kfree_rcu(rqstp, rq_rcu_head); } static struct svc_rqst * svc_prepare_thread(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; folio_batch_init(&rqstp->rq_fbatch); rqstp->rq_server = serv; rqstp->rq_pool = pool; rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0); if (!rqstp->rq_scratch_page) goto out_enomem; 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; rqstp->rq_err = -EAGAIN; /* No error yet */ serv->sv_nrthreads += 1; pool->sp_nrthreads += 1; /* Protected by whatever lock the service uses when calling * svc_set_num_threads() */ list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads); return rqstp; out_enomem: svc_rqst_free(rqstp); return NULL; } /** * svc_pool_wake_idle_thread - Awaken an idle thread in @pool * @pool: service thread pool * * Can be called from soft IRQ or process context. Finding an idle * service thread and marking it BUSY is atomic with respect to * other calls to svc_pool_wake_idle_thread(). * */ void svc_pool_wake_idle_thread(struct svc_pool *pool) { struct svc_rqst *rqstp; struct llist_node *ln; rcu_read_lock(); ln = READ_ONCE(pool->sp_idle_threads.first); if (ln) { rqstp = llist_entry(ln, struct svc_rqst, rq_idle); WRITE_ONCE(rqstp->rq_qtime, ktime_get()); if (!task_is_running(rqstp->rq_task)) { wake_up_process(rqstp->rq_task); trace_svc_wake_up(rqstp->rq_task->pid); percpu_counter_inc(&pool->sp_threads_woken); } rcu_read_unlock(); return; } rcu_read_unlock(); } EXPORT_SYMBOL_GPL(svc_pool_wake_idle_thread); static struct svc_pool * svc_pool_next(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state) { return pool ? pool : &serv->sv_pools[(*state)++ % serv->sv_nrpools]; } static struct svc_pool * svc_pool_victim(struct svc_serv *serv, struct svc_pool *target_pool, unsigned int *state) { struct svc_pool *pool; unsigned int i; pool = target_pool; if (!pool) { for (i = 0; i < serv->sv_nrpools; i++) { pool = &serv->sv_pools[--(*state) % serv->sv_nrpools]; if (pool->sp_nrthreads) break; } } if (pool && pool->sp_nrthreads) { set_bit(SP_VICTIM_REMAINS, &pool->sp_flags); set_bit(SP_NEED_VICTIM, &pool->sp_flags); return pool; } return NULL; } 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; int err; do { nrservs--; chosen_pool = svc_pool_next(serv, pool, &state); node = svc_pool_map_get_node(chosen_pool->sp_id); rqstp = svc_prepare_thread(serv, chosen_pool, node); if (!rqstp) return -ENOMEM; task = kthread_create_on_node(serv->sv_threadfn, rqstp, node, "%s", serv->sv_name); if (IS_ERR(task)) { 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); wait_var_event(&rqstp->rq_err, rqstp->rq_err != -EAGAIN); err = rqstp->rq_err; if (err) { svc_exit_thread(rqstp); return err; } } while (nrservs > 0); return 0; } static int svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { unsigned int state = serv->sv_nrthreads-1; struct svc_pool *victim; do { victim = svc_pool_victim(serv, pool, &state); if (!victim) break; svc_pool_wake_idle_thread(victim); wait_on_bit(&victim->sp_flags, SP_VICTIM_REMAINS, TASK_IDLE); nrservs++; } while (nrservs < 0); return 0; } /** * svc_set_num_threads - adjust number of threads per RPC service * @serv: RPC service to adjust * @pool: Specific pool from which to choose threads, or NULL * @nrservs: New number of threads for @serv (0 or less means kill all threads) * * Create or destroy threads to make the number of threads for @serv the * given number. If @pool is non-NULL, change only threads in that pool; * otherwise, round-robin between all pools for @serv. @serv's * sv_nrthreads is adjusted for each thread created or destroyed. * * Caller must ensure mutual exclusion between this and server startup or * shutdown. * * Returns zero on success or a negative errno if an error occurred while * starting a thread. */ int svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { if (!pool) nrservs -= serv->sv_nrthreads; else nrservs -= pool->sp_nrthreads; 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); /** * svc_rqst_replace_page - Replace one page in rq_pages[] * @rqstp: svc_rqst with pages to replace * @page: replacement page * * When replacing a page in rq_pages, batch the release of the * replaced pages to avoid hammering the page allocator. * * Return values: * %true: page replaced * %false: array bounds checking failed */ bool svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page) { struct page **begin = rqstp->rq_pages; struct page **end = &rqstp->rq_pages[RPCSVC_MAXPAGES]; if (unlikely(rqstp->rq_next_page < begin || rqstp->rq_next_page > end)) { trace_svc_replace_page_err(rqstp); return false; } if (*rqstp->rq_next_page) { if (!folio_batch_add(&rqstp->rq_fbatch, page_folio(*rqstp->rq_next_page))) __folio_batch_release(&rqstp->rq_fbatch); } get_page(page); *(rqstp->rq_next_page++) = page; return true; } EXPORT_SYMBOL_GPL(svc_rqst_replace_page); /** * svc_rqst_release_pages - Release Reply buffer pages * @rqstp: RPC transaction context * * Release response pages that might still be in flight after * svc_send, and any spliced filesystem-owned pages. */ void svc_rqst_release_pages(struct svc_rqst *rqstp) { int i, count = rqstp->rq_next_page - rqstp->rq_respages; if (count) { release_pages(rqstp->rq_respages, count); for (i = 0; i < count; i++) rqstp->rq_respages[i] = NULL; } } /** * svc_exit_thread - finalise the termination of a sunrpc server thread * @rqstp: the svc_rqst which represents the thread. * * When a thread started with svc_new_thread() exits it must call * svc_exit_thread() as its last act. This must be done with the * service mutex held. Normally this is held by a DIFFERENT thread, the * one that is calling svc_set_num_threads() and which will wait for * SP_VICTIM_REMAINS to be cleared before dropping the mutex. If the * thread exits for any reason other than svc_thread_should_stop() * returning %true (which indicated that svc_set_num_threads() is * waiting for it to exit), then it must take the service mutex itself, * which can only safely be done using mutex_try_lock(). */ void svc_exit_thread(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct svc_pool *pool = rqstp->rq_pool; list_del_rcu(&rqstp->rq_all); pool->sp_nrthreads -= 1; serv->sv_nrthreads -= 1; svc_sock_update_bufs(serv); svc_rqst_free(rqstp); clear_and_wake_up_bit(SP_VICTIM_REMAINS, &pool->sp_flags); } 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 } trace_svc_register(progname, version, family, protocol, port, error); return error; } static int svc_rpcbind_set_version(struct net *net, const struct svc_program *progp, u32 version, int family, unsigned short proto, unsigned short port) { return __svc_register(net, progp->pg_name, progp->pg_prog, version, family, proto, port); } 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) { trace_svc_noregister(progp->pg_name, version, proto, port, family, 0); 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) { unsigned int p, i; int error = 0; WARN_ON_ONCE(proto == 0 && port == 0); if (proto == 0 && port == 0) return -EINVAL; for (p = 0; p < serv->sv_nprogs; p++) { struct svc_program *progp = &serv->sv_programs[p]; 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); trace_svc_unregister(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 sighand_struct *sighand; unsigned long flags; unsigned int p, i; clear_thread_flag(TIF_SIGPENDING); for (p = 0; p < serv->sv_nprogs; p++) { struct svc_program *progp = &serv->sv_programs[p]; for (i = 0; i < progp->pg_nvers; i++) { if (progp->pg_vers[i] == NULL) continue; if (progp->pg_vers[i]->vs_hidden) continue; __svc_unregister(net, progp->pg_prog, i, progp->pg_name); } } rcu_read_lock(); sighand = rcu_dereference(current->sighand); spin_lock_irqsave(&sighand->siglock, flags); recalc_sigpending(); spin_unlock_irqrestore(&sighand->siglock, flags); rcu_read_unlock(); } /* * 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_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_argzero); memset(rqstp->rq_resp, 0, procp->pc_ressize); /* Bump per-procedure stats counter */ this_cpu_inc(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 xdr_stream *xdr = &rqstp->rq_res_stream; struct svc_program *progp = NULL; const struct svc_procedure *procp = NULL; struct svc_serv *serv = rqstp->rq_server; struct svc_process_info process; enum svc_auth_status auth_res; unsigned int aoffset; int pr, rc; __be32 *p; /* Will be turned off only when NFSv4 Sessions are used */ set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); clear_bit(RQ_DROPME, &rqstp->rq_flags); /* Construct the first words of the reply: */ svcxdr_init_encode(rqstp); xdr_stream_encode_be32(xdr, rqstp->rq_xid); xdr_stream_encode_be32(xdr, rpc_reply); p = xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 4); if (unlikely(!p)) goto err_short_len; if (*p++ != cpu_to_be32(RPC_VERSION)) goto err_bad_rpc; xdr_stream_encode_be32(xdr, rpc_msg_accepted); rqstp->rq_prog = be32_to_cpup(p++); rqstp->rq_vers = be32_to_cpup(p++); rqstp->rq_proc = be32_to_cpup(p); for (pr = 0; pr < serv->sv_nprogs; pr++) if (rqstp->rq_prog == serv->sv_programs[pr].pg_prog) progp = &serv->sv_programs[pr]; /* * 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); /* Also give the program a chance to reject this call: */ if (auth_res == SVC_OK && progp) auth_res = progp->pg_authenticate(rqstp); trace_svc_authenticate(rqstp, auth_res); switch (auth_res) { case SVC_OK: break; case SVC_GARBAGE: goto err_garbage_args; case SVC_SYSERR: goto err_system_err; case SVC_DENIED: goto err_bad_auth; case SVC_CLOSE: goto close; case SVC_DROP: goto dropit; case SVC_COMPLETE: goto sendit; default: pr_warn_once("Unexpected svc_auth_status (%d)\n", auth_res); goto err_system_err; } if (progp == NULL) goto err_bad_prog; switch (progp->pg_init_request(rqstp, progp, &process)) { 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 */ if (serv->sv_stats) serv->sv_stats->rpccnt++; trace_svc_process(rqstp, progp->pg_name); aoffset = xdr_stream_pos(xdr); /* 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. */ rc = process.dispatch(rqstp); if (procp->pc_release) procp->pc_release(rqstp); xdr_finish_decode(xdr); if (!rc) goto dropit; if (rqstp->rq_auth_stat != rpc_auth_ok) goto err_bad_auth; if (*rqstp->rq_accept_statp != rpc_success) xdr_truncate_encode(xdr, aoffset); if (procp->pc_encode == NULL) goto dropit; sendit: if (svc_authorise(rqstp)) goto close_xprt; return 1; /* Caller can now send it */ 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_xprt_close(rqstp->rq_xprt); dprintk("svc: svc_process close\n"); return 0; err_short_len: svc_printk(rqstp, "short len %u, dropping request\n", rqstp->rq_arg.len); goto close_xprt; err_bad_rpc: if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; xdr_stream_encode_u32(xdr, RPC_MSG_DENIED); xdr_stream_encode_u32(xdr, RPC_MISMATCH); /* Only RPCv2 supported */ xdr_stream_encode_u32(xdr, RPC_VERSION); xdr_stream_encode_u32(xdr, RPC_VERSION); return 1; /* don't wrap */ err_bad_auth: dprintk("svc: authentication failed (%d)\n", be32_to_cpu(rqstp->rq_auth_stat)); if (serv->sv_stats) serv->sv_stats->rpcbadauth++; /* Restore write pointer to location of reply status: */ xdr_truncate_encode(xdr, XDR_UNIT * 2); xdr_stream_encode_u32(xdr, RPC_MSG_DENIED); xdr_stream_encode_u32(xdr, RPC_AUTH_ERROR); xdr_stream_encode_be32(xdr, rqstp->rq_auth_stat); goto sendit; err_bad_prog: dprintk("svc: unknown program %d\n", rqstp->rq_prog); if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; *rqstp->rq_accept_statp = 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); if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; *rqstp->rq_accept_statp = rpc_prog_mismatch; /* * svc_authenticate() has already added the verifier and * advanced the stream just past rq_accept_statp. */ xdr_stream_encode_u32(xdr, process.mismatch.lovers); xdr_stream_encode_u32(xdr, process.mismatch.hivers); goto sendit; err_bad_proc: svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc); if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; *rqstp->rq_accept_statp = rpc_proc_unavail; goto sendit; err_garbage_args: svc_printk(rqstp, "failed to decode RPC header\n"); if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; *rqstp->rq_accept_statp = rpc_garbage_args; goto sendit; err_system_err: if (serv->sv_stats) serv->sv_stats->rpcbadfmt++; *rqstp->rq_accept_statp = rpc_system_err; goto sendit; } /* * Drop request */ static void svc_drop(struct svc_rqst *rqstp) { trace_svc_drop(rqstp); } /** * svc_process - Execute one RPC transaction * @rqstp: RPC transaction context * */ void svc_process(struct svc_rqst *rqstp) { struct kvec *resv = &rqstp->rq_res.head[0]; __be32 *p; #if IS_ENABLED(CONFIG_FAIL_SUNRPC) if (!fail_sunrpc.ignore_server_disconnect && should_fail(&fail_sunrpc.attr, 1)) svc_xprt_deferred_close(rqstp->rq_xprt); #endif /* * 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_next_page; 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; svcxdr_init_decode(rqstp); p = xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2); if (unlikely(!p)) goto out_drop; rqstp->rq_xid = *p++; if (unlikely(*p != rpc_call)) goto out_baddir; if (!svc_process_common(rqstp)) goto out_drop; svc_send(rqstp); return; out_baddir: svc_printk(rqstp, "bad direction 0x%08x, dropping request\n", be32_to_cpu(*p)); if (rqstp->rq_server->sv_stats) rqstp->rq_server->sv_stats->rpcbadfmt++; out_drop: svc_drop(rqstp); } #if defined(CONFIG_SUNRPC_BACKCHANNEL) /** * svc_process_bc - process a reverse-direction RPC request * @req: RPC request to be used for client-side processing * @rqstp: server-side execution context * */ void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp) { struct rpc_timeout timeout = { .to_increment = 0, }; struct rpc_task *task; int proc_error; /* 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_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 the response buffer */ rqstp->rq_res.head[0].iov_len = 0; /* * Skip the XID and calldir fields because they've already * been processed by the caller. */ svcxdr_init_decode(rqstp); if (!xdr_inline_decode(&rqstp->rq_arg_stream, XDR_UNIT * 2)) return; /* Parse and execute the bc call */ proc_error = svc_process_common(rqstp); atomic_dec(&req->rq_xprt->bc_slot_count); if (!proc_error) { /* Processing error: drop the request */ xprt_free_bc_request(req); return; } /* Finally, send the reply synchronously */ if (rqstp->bc_to_initval > 0) { timeout.to_initval = rqstp->bc_to_initval; timeout.to_retries = rqstp->bc_to_retries; } else { timeout.to_initval = req->rq_xprt->timeout->to_initval; timeout.to_retries = req->rq_xprt->timeout->to_retries; } timeout.to_maxval = timeout.to_initval; memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf)); task = rpc_run_bc_task(req, &timeout); if (IS_ERR(task)) return; WARN_ON_ONCE(atomic_read(&task->tk_count) != 1); rpc_put_task(task); } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ /** * svc_max_payload - Return transport-specific limit on the RPC payload * @rqstp: RPC transaction context * * Returns the maximum number of payload bytes the current transport * allows. */ 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_proc_name - Return RPC procedure name in string form * @rqstp: svc_rqst to operate on * * Return value: * Pointer to a NUL-terminated string */ const char *svc_proc_name(const struct svc_rqst *rqstp) { if (rqstp && rqstp->rq_procinfo) return rqstp->rq_procinfo->pc_name; return "unknown"; } /** * svc_encode_result_payload - mark a range of bytes as a result 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_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length) { return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset, length); } EXPORT_SYMBOL_GPL(svc_encode_result_payload); /** * svc_fill_write_vector - Construct data argument for VFS write call * @rqstp: svc_rqst to operate on * @payload: xdr_buf containing only the write data payload * * Fills in rqstp::rq_vec, and returns the number of elements. */ unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct xdr_buf *payload) { struct page **pages = payload->pages; struct kvec *first = payload->head; struct kvec *vec = rqstp->rq_vec; size_t total = payload->len; 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);