/* * 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.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/sunrpc/types.h> #include <linux/sunrpc/xdr.h> #include <linux/sunrpc/stats.h> #include <linux/sunrpc/svcsock.h> #include <linux/sunrpc/clnt.h> #define RPCDBG_FACILITY RPCDBG_SVCDSP #define RPC_PARANOIA 1 /* * Mode for mapping cpus to pools. */ enum { SVC_POOL_NONE = -1, /* uninitialised, 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. */ static struct svc_pool_map { 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 */ } svc_pool_map = { .mode = SVC_POOL_NONE }; /* * Detect best pool mapping mode heuristically, * according to the machine's topology. */ static int svc_pool_map_choose_mode(void) { unsigned int node; if (num_online_nodes() > 1) { /* * Actually have multiple NUMA nodes, * so split pools on NUMA node boundaries */ return SVC_POOL_PERNODE; } node = any_online_node(node_online_map); 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); 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 = highest_possible_processor_id()+1; 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 = highest_possible_node_id()+1; 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; } /* * Build the global map of cpus to pools and vice versa. */ static unsigned int svc_pool_map_init(void) { struct svc_pool_map *m = &svc_pool_map; int npools = -1; if (m->mode != SVC_POOL_NONE) return m->npools; 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; return m->npools; } /* * Set the current thread's cpus_allowed mask so that it * will only run on cpus in the given pool. * * Returns 1 and fills in oldmask iff a cpumask was applied. */ static inline int svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask) { struct svc_pool_map *m = &svc_pool_map; unsigned int node; /* or cpu */ /* * The caller checks for sv_nrpools > 1, which * implies that we've been initialized and the * map mode is not NONE. */ BUG_ON(m->mode == SVC_POOL_NONE); switch (m->mode) { default: return 0; case SVC_POOL_PERCPU: node = m->pool_to[pidx]; *oldmask = current->cpus_allowed; set_cpus_allowed(current, cpumask_of_cpu(node)); return 1; case SVC_POOL_PERNODE: node = m->pool_to[pidx]; *oldmask = current->cpus_allowed; set_cpus_allowed(current, node_to_cpumask(node)); return 1; } } /* * 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; /* * SVC_POOL_NONE happens in a pure client when * lockd is brought up, so silently treat it the * same as SVC_POOL_GLOBAL. */ 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]; } /* * Create an RPC service */ static struct svc_serv * __svc_create(struct svc_program *prog, unsigned int bufsize, int npools, void (*shutdown)(struct svc_serv *serv)) { struct svc_serv *serv; 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; serv->sv_bufsz = bufsize? bufsize : 4096; serv->sv_shutdown = shutdown; 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); init_timer(&serv->sv_temptimer); spin_lock_init(&serv->sv_lock); serv->sv_nrpools = npools; serv->sv_pools = kcalloc(sizeof(struct svc_pool), serv->sv_nrpools, 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("initialising pool %u for %s\n", i, serv->sv_name); pool->sp_id = i; INIT_LIST_HEAD(&pool->sp_threads); INIT_LIST_HEAD(&pool->sp_sockets); INIT_LIST_HEAD(&pool->sp_all_threads); spin_lock_init(&pool->sp_lock); } /* Remove any stale portmap registrations */ svc_register(serv, 0, 0); return serv; } struct svc_serv * svc_create(struct svc_program *prog, unsigned int bufsize, void (*shutdown)(struct svc_serv *serv)) { return __svc_create(prog, bufsize, /*npools*/1, shutdown); } struct svc_serv * svc_create_pooled(struct svc_program *prog, unsigned int bufsize, void (*shutdown)(struct svc_serv *serv), svc_thread_fn func, int sig, struct module *mod) { struct svc_serv *serv; unsigned int npools = svc_pool_map_init(); serv = __svc_create(prog, bufsize, npools, shutdown); if (serv != NULL) { serv->sv_function = func; serv->sv_kill_signal = sig; serv->sv_module = mod; } return serv; } /* * Destroy an RPC service. Should be called with the BKL held */ void svc_destroy(struct svc_serv *serv) { struct svc_sock *svsk; dprintk("RPC: 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); while (!list_empty(&serv->sv_tempsocks)) { svsk = list_entry(serv->sv_tempsocks.next, struct svc_sock, sk_list); svc_delete_socket(svsk); } if (serv->sv_shutdown) serv->sv_shutdown(serv); while (!list_empty(&serv->sv_permsocks)) { svsk = list_entry(serv->sv_permsocks.next, struct svc_sock, sk_list); svc_delete_socket(svsk); } cache_clean_deferred(serv); /* Unregister service with the portmapper */ svc_register(serv, 0, 0); kfree(serv->sv_pools); kfree(serv); } /* * 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 pages; int arghi; if (size > RPCSVC_MAXPAYLOAD) size = RPCSVC_MAXPAYLOAD; pages = 2 + (size+ PAGE_SIZE -1) / PAGE_SIZE; arghi = 0; BUG_ON(pages > RPCSVC_MAXPAGES); while (pages) { struct page *p = alloc_page(GFP_KERNEL); if (!p) break; rqstp->rq_pages[arghi++] = p; pages--; } return ! pages; } /* * Release an RPC server buffer */ static void svc_release_buffer(struct svc_rqst *rqstp) { int i; for (i=0; i<ARRAY_SIZE(rqstp->rq_pages); i++) if (rqstp->rq_pages[i]) put_page(rqstp->rq_pages[i]); } /* * Create a thread in the given pool. Caller must hold BKL. * On a NUMA or SMP machine, with a multi-pool serv, the thread * will be restricted to run on the cpus belonging to the pool. */ static int __svc_create_thread(svc_thread_fn func, struct svc_serv *serv, struct svc_pool *pool) { struct svc_rqst *rqstp; int error = -ENOMEM; int have_oldmask = 0; cpumask_t oldmask; rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL); if (!rqstp) goto out; init_waitqueue_head(&rqstp->rq_wait); if (!(rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL)) || !(rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL)) || !svc_init_buffer(rqstp, serv->sv_bufsz)) goto out_thread; serv->sv_nrthreads++; spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads++; list_add(&rqstp->rq_all, &pool->sp_all_threads); spin_unlock_bh(&pool->sp_lock); rqstp->rq_server = serv; rqstp->rq_pool = pool; if (serv->sv_nrpools > 1) have_oldmask = svc_pool_map_set_cpumask(pool->sp_id, &oldmask); error = kernel_thread((int (*)(void *)) func, rqstp, 0); if (have_oldmask) set_cpus_allowed(current, oldmask); if (error < 0) goto out_thread; svc_sock_update_bufs(serv); error = 0; out: return error; out_thread: svc_exit_thread(rqstp); goto out; } /* * Create a thread in the default pool. Caller must hold BKL. */ int svc_create_thread(svc_thread_fn func, struct svc_serv *serv) { return __svc_create_thread(func, serv, &serv->sv_pools[0]); } /* * 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); list_del_init(&rqstp->rq_all); task = rqstp->rq_task; } spin_unlock_bh(&pool->sp_lock); return task; } /* * 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. Must be called with a svc_get() reference and * the BKL held. * * 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) { struct task_struct *victim; int error = 0; unsigned int state = serv->sv_nrthreads-1; 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); } /* create new threads */ while (nrservs > 0) { nrservs--; __module_get(serv->sv_module); error = __svc_create_thread(serv->sv_function, serv, choose_pool(serv, pool, &state)); if (error < 0) { module_put(serv->sv_module); break; } } /* destroy old threads */ while (nrservs < 0 && (victim = choose_victim(serv, pool, &state)) != NULL) { send_sig(serv->sv_kill_signal, victim, 1); nrservs++; } return error; } /* * Called from a server thread as it's exiting. Caller must hold BKL. */ void svc_exit_thread(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct svc_pool *pool = rqstp->rq_pool; svc_release_buffer(rqstp); kfree(rqstp->rq_resp); kfree(rqstp->rq_argp); kfree(rqstp->rq_auth_data); spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads--; list_del(&rqstp->rq_all); spin_unlock_bh(&pool->sp_lock); kfree(rqstp); /* Release the server */ if (serv) svc_destroy(serv); } /* * Register an RPC service with the local portmapper. * To unregister a service, call this routine with * proto and port == 0. */ int svc_register(struct svc_serv *serv, int proto, unsigned short port) { struct svc_program *progp; unsigned long flags; int i, error = 0, dummy; progp = serv->sv_program; dprintk("RPC: svc_register(%s, %s, %d)\n", progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port); if (!port) clear_thread_flag(TIF_SIGPENDING); for (i = 0; i < progp->pg_nvers; i++) { if (progp->pg_vers[i] == NULL) continue; error = rpc_register(progp->pg_prog, i, proto, port, &dummy); if (error < 0) break; if (port && !dummy) { error = -EACCES; break; } } if (!port) { spin_lock_irqsave(¤t->sighand->siglock, flags); recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); } return error; } /* * Process the RPC request. */ int svc_process(struct svc_rqst *rqstp) { struct svc_program *progp; struct svc_version *versp = NULL; /* compiler food */ struct svc_procedure *procp = NULL; struct kvec * argv = &rqstp->rq_arg.head[0]; struct kvec * resv = &rqstp->rq_res.head[0]; struct svc_serv *serv = rqstp->rq_server; kxdrproc_t xdr; __be32 *statp; u32 dir, prog, vers, proc; __be32 auth_stat, rpc_stat; int auth_res; __be32 *accept_statp; rpc_stat = rpc_success; if (argv->iov_len < 6*4) goto err_short_len; /* setup response xdr_buf. * Initially it has just one page */ rqstp->rq_resused = 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; /* Will be turned off only in gss privacy case: */ rqstp->rq_sendfile_ok = 1; /* tcp needs a space for the record length... */ if (rqstp->rq_prot == IPPROTO_TCP) svc_putnl(resv, 0); rqstp->rq_xid = svc_getu32(argv); svc_putu32(resv, rqstp->rq_xid); dir = svc_getnl(argv); vers = svc_getnl(argv); /* First words of reply: */ svc_putnl(resv, 1); /* REPLY */ if (dir != 0) /* direction != CALL */ goto err_bad_dir; if (vers != 2) /* RPC version number */ goto err_bad_rpc; /* Save position in case we later decide to reject: */ accept_statp = resv->iov_base + resv->iov_len; svc_putnl(resv, 0); /* ACCEPT */ rqstp->rq_prog = prog = svc_getnl(argv); /* program number */ rqstp->rq_vers = vers = svc_getnl(argv); /* version number */ rqstp->rq_proc = proc = svc_getnl(argv); /* procedure number */ progp = serv->sv_program; 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: rpc_stat = rpc_garbage_args; goto err_bad; case SVC_SYSERR: rpc_stat = rpc_system_err; goto err_bad; case SVC_DENIED: goto err_bad_auth; case SVC_DROP: goto dropit; case SVC_COMPLETE: goto sendit; } if (progp == NULL) goto err_bad_prog; if (vers >= progp->pg_nvers || !(versp = progp->pg_vers[vers])) goto err_bad_vers; procp = versp->vs_proc + proc; if (proc >= versp->vs_nproc || !procp->pc_func) goto err_bad_proc; rqstp->rq_server = serv; rqstp->rq_procinfo = procp; /* Syntactic check complete */ serv->sv_stats->rpccnt++; /* Build the reply header. */ statp = resv->iov_base +resv->iov_len; svc_putnl(resv, RPC_SUCCESS); /* Bump per-procedure stats counter */ procp->pc_count++; /* Initialize storage for argp and resp */ memset(rqstp->rq_argp, 0, procp->pc_argsize); memset(rqstp->rq_resp, 0, procp->pc_ressize); /* un-reserve some of the out-queue now that we have a * better idea of reply size */ if (procp->pc_xdrressize) svc_reserve(rqstp, procp->pc_xdrressize<<2); /* Call the function that processes the request. */ if (!versp->vs_dispatch) { /* Decode arguments */ xdr = procp->pc_decode; if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp)) goto err_garbage; *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); /* Encode reply */ if (*statp == rpc_success && (xdr = procp->pc_encode) && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) { dprintk("svc: failed to encode reply\n"); /* serv->sv_stats->rpcsystemerr++; */ *statp = rpc_system_err; } } else { dprintk("svc: calling dispatcher\n"); if (!versp->vs_dispatch(rqstp, statp)) { /* Release reply info */ if (procp->pc_release) procp->pc_release(rqstp, NULL, rqstp->rq_resp); goto dropit; } } /* 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, NULL, rqstp->rq_resp); if (procp->pc_encode == NULL) goto dropit; sendit: if (svc_authorise(rqstp)) goto dropit; return svc_send(rqstp); dropit: svc_authorise(rqstp); /* doesn't hurt to call this twice */ dprintk("svc: svc_process dropit\n"); svc_drop(rqstp); return 0; err_short_len: #ifdef RPC_PARANOIA printk("svc: short len %Zd, dropping request\n", argv->iov_len); #endif goto dropit; /* drop request */ err_bad_dir: #ifdef RPC_PARANOIA printk("svc: bad direction %d, dropping request\n", dir); #endif serv->sv_stats->rpcbadfmt++; goto dropit; /* drop request */ 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_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, accept_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: #ifdef RPC_PARANOIA printk("svc: unknown version (%d)\n", vers); #endif serv->sv_stats->rpcbadfmt++; svc_putnl(resv, RPC_PROG_MISMATCH); svc_putnl(resv, progp->pg_lovers); svc_putnl(resv, progp->pg_hivers); goto sendit; err_bad_proc: #ifdef RPC_PARANOIA printk("svc: unknown procedure (%d)\n", proc); #endif serv->sv_stats->rpcbadfmt++; svc_putnl(resv, RPC_PROC_UNAVAIL); goto sendit; err_garbage: #ifdef RPC_PARANOIA printk("svc: failed to decode args\n"); #endif rpc_stat = rpc_garbage_args; err_bad: serv->sv_stats->rpcbadfmt++; svc_putnl(resv, ntohl(rpc_stat)); goto sendit; }