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v6.2
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * linux/net/sunrpc/svc.c
   4 *
   5 * High-level RPC service routines
   6 *
   7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8 *
   9 * Multiple threads pools and NUMAisation
  10 * Copyright (c) 2006 Silicon Graphics, Inc.
  11 * by Greg Banks <gnb@melbourne.sgi.com>
  12 */
  13
  14#include <linux/linkage.h>
  15#include <linux/sched/signal.h>
  16#include <linux/errno.h>
  17#include <linux/net.h>
  18#include <linux/in.h>
  19#include <linux/mm.h>
  20#include <linux/interrupt.h>
  21#include <linux/module.h>
  22#include <linux/kthread.h>
  23#include <linux/slab.h>
 
  24
  25#include <linux/sunrpc/types.h>
  26#include <linux/sunrpc/xdr.h>
  27#include <linux/sunrpc/stats.h>
  28#include <linux/sunrpc/svcsock.h>
  29#include <linux/sunrpc/clnt.h>
  30#include <linux/sunrpc/bc_xprt.h>
  31
  32#include <trace/events/sunrpc.h>
  33
  34#include "fail.h"
  35
  36#define RPCDBG_FACILITY	RPCDBG_SVCDSP
  37
  38static void svc_unregister(const struct svc_serv *serv, struct net *net);
  39
  40#define SVC_POOL_DEFAULT	SVC_POOL_GLOBAL
  41
  42/*
  43 * Mode for mapping cpus to pools.
  44 */
  45enum {
  46	SVC_POOL_AUTO = -1,	/* choose one of the others */
  47	SVC_POOL_GLOBAL,	/* no mapping, just a single global pool
  48				 * (legacy & UP mode) */
  49	SVC_POOL_PERCPU,	/* one pool per cpu */
  50	SVC_POOL_PERNODE	/* one pool per numa node */
  51};
 
  52
  53/*
  54 * Structure for mapping cpus to pools and vice versa.
  55 * Setup once during sunrpc initialisation.
  56 */
  57
  58struct svc_pool_map {
  59	int count;			/* How many svc_servs use us */
  60	int mode;			/* Note: int not enum to avoid
  61					 * warnings about "enumeration value
  62					 * not handled in switch" */
  63	unsigned int npools;
  64	unsigned int *pool_to;		/* maps pool id to cpu or node */
  65	unsigned int *to_pool;		/* maps cpu or node to pool id */
  66};
  67
  68static struct svc_pool_map svc_pool_map = {
  69	.mode = SVC_POOL_DEFAULT
  70};
  71
  72static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
  73
  74static int
  75param_set_pool_mode(const char *val, const struct kernel_param *kp)
  76{
  77	int *ip = (int *)kp->arg;
  78	struct svc_pool_map *m = &svc_pool_map;
  79	int err;
  80
  81	mutex_lock(&svc_pool_map_mutex);
  82
  83	err = -EBUSY;
  84	if (m->count)
  85		goto out;
  86
  87	err = 0;
  88	if (!strncmp(val, "auto", 4))
  89		*ip = SVC_POOL_AUTO;
  90	else if (!strncmp(val, "global", 6))
  91		*ip = SVC_POOL_GLOBAL;
  92	else if (!strncmp(val, "percpu", 6))
  93		*ip = SVC_POOL_PERCPU;
  94	else if (!strncmp(val, "pernode", 7))
  95		*ip = SVC_POOL_PERNODE;
  96	else
  97		err = -EINVAL;
  98
  99out:
 100	mutex_unlock(&svc_pool_map_mutex);
 101	return err;
 102}
 103
 104static int
 105param_get_pool_mode(char *buf, const struct kernel_param *kp)
 106{
 107	int *ip = (int *)kp->arg;
 108
 109	switch (*ip)
 110	{
 111	case SVC_POOL_AUTO:
 112		return strlcpy(buf, "auto\n", 20);
 113	case SVC_POOL_GLOBAL:
 114		return strlcpy(buf, "global\n", 20);
 115	case SVC_POOL_PERCPU:
 116		return strlcpy(buf, "percpu\n", 20);
 117	case SVC_POOL_PERNODE:
 118		return strlcpy(buf, "pernode\n", 20);
 119	default:
 120		return sprintf(buf, "%d\n", *ip);
 121	}
 122}
 123
 124module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
 125		 &svc_pool_map.mode, 0644);
 126
 127/*
 128 * Detect best pool mapping mode heuristically,
 129 * according to the machine's topology.
 130 */
 131static int
 132svc_pool_map_choose_mode(void)
 133{
 134	unsigned int node;
 135
 136	if (nr_online_nodes > 1) {
 137		/*
 138		 * Actually have multiple NUMA nodes,
 139		 * so split pools on NUMA node boundaries
 140		 */
 141		return SVC_POOL_PERNODE;
 142	}
 143
 144	node = first_online_node;
 145	if (nr_cpus_node(node) > 2) {
 146		/*
 147		 * Non-trivial SMP, or CONFIG_NUMA on
 148		 * non-NUMA hardware, e.g. with a generic
 149		 * x86_64 kernel on Xeons.  In this case we
 150		 * want to divide the pools on cpu boundaries.
 151		 */
 152		return SVC_POOL_PERCPU;
 153	}
 154
 155	/* default: one global pool */
 156	return SVC_POOL_GLOBAL;
 157}
 158
 159/*
 160 * Allocate the to_pool[] and pool_to[] arrays.
 161 * Returns 0 on success or an errno.
 162 */
 163static int
 164svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
 165{
 166	m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 167	if (!m->to_pool)
 168		goto fail;
 169	m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 170	if (!m->pool_to)
 171		goto fail_free;
 172
 173	return 0;
 174
 175fail_free:
 176	kfree(m->to_pool);
 177	m->to_pool = NULL;
 178fail:
 179	return -ENOMEM;
 180}
 181
 182/*
 183 * Initialise the pool map for SVC_POOL_PERCPU mode.
 184 * Returns number of pools or <0 on error.
 185 */
 186static int
 187svc_pool_map_init_percpu(struct svc_pool_map *m)
 188{
 189	unsigned int maxpools = nr_cpu_ids;
 190	unsigned int pidx = 0;
 191	unsigned int cpu;
 192	int err;
 193
 194	err = svc_pool_map_alloc_arrays(m, maxpools);
 195	if (err)
 196		return err;
 197
 198	for_each_online_cpu(cpu) {
 199		BUG_ON(pidx >= maxpools);
 200		m->to_pool[cpu] = pidx;
 201		m->pool_to[pidx] = cpu;
 202		pidx++;
 203	}
 204	/* cpus brought online later all get mapped to pool0, sorry */
 205
 206	return pidx;
 207};
 208
 209
 210/*
 211 * Initialise the pool map for SVC_POOL_PERNODE mode.
 212 * Returns number of pools or <0 on error.
 213 */
 214static int
 215svc_pool_map_init_pernode(struct svc_pool_map *m)
 216{
 217	unsigned int maxpools = nr_node_ids;
 218	unsigned int pidx = 0;
 219	unsigned int node;
 220	int err;
 221
 222	err = svc_pool_map_alloc_arrays(m, maxpools);
 223	if (err)
 224		return err;
 225
 226	for_each_node_with_cpus(node) {
 227		/* some architectures (e.g. SN2) have cpuless nodes */
 228		BUG_ON(pidx > maxpools);
 229		m->to_pool[node] = pidx;
 230		m->pool_to[pidx] = node;
 231		pidx++;
 232	}
 233	/* nodes brought online later all get mapped to pool0, sorry */
 234
 235	return pidx;
 236}
 237
 238
 239/*
 240 * Add a reference to the global map of cpus to pools (and
 241 * vice versa) if pools are in use.
 242 * Initialise the map if we're the first user.
 243 * Returns the number of pools. If this is '1', no reference
 244 * was taken.
 245 */
 246static unsigned int
 247svc_pool_map_get(void)
 248{
 249	struct svc_pool_map *m = &svc_pool_map;
 250	int npools = -1;
 251
 252	mutex_lock(&svc_pool_map_mutex);
 253
 254	if (m->count++) {
 255		mutex_unlock(&svc_pool_map_mutex);
 256		WARN_ON_ONCE(m->npools <= 1);
 257		return m->npools;
 258	}
 259
 260	if (m->mode == SVC_POOL_AUTO)
 261		m->mode = svc_pool_map_choose_mode();
 262
 263	switch (m->mode) {
 264	case SVC_POOL_PERCPU:
 265		npools = svc_pool_map_init_percpu(m);
 266		break;
 267	case SVC_POOL_PERNODE:
 268		npools = svc_pool_map_init_pernode(m);
 269		break;
 270	}
 271
 272	if (npools <= 0) {
 273		/* default, or memory allocation failure */
 274		npools = 1;
 275		m->mode = SVC_POOL_GLOBAL;
 276	}
 277	m->npools = npools;
 278
 279	if (npools == 1)
 280		/* service is unpooled, so doesn't hold a reference */
 281		m->count--;
 282
 283	mutex_unlock(&svc_pool_map_mutex);
 284	return npools;
 285}
 286
 
 287/*
 288 * Drop a reference to the global map of cpus to pools, if
 289 * pools were in use, i.e. if npools > 1.
 290 * When the last reference is dropped, the map data is
 291 * freed; this allows the sysadmin to change the pool
 292 * mode using the pool_mode module option without
 293 * rebooting or re-loading sunrpc.ko.
 294 */
 295static void
 296svc_pool_map_put(int npools)
 297{
 298	struct svc_pool_map *m = &svc_pool_map;
 299
 300	if (npools <= 1)
 301		return;
 302	mutex_lock(&svc_pool_map_mutex);
 303
 304	if (!--m->count) {
 305		kfree(m->to_pool);
 306		m->to_pool = NULL;
 307		kfree(m->pool_to);
 308		m->pool_to = NULL;
 309		m->npools = 0;
 310	}
 311
 312	mutex_unlock(&svc_pool_map_mutex);
 313}
 314
 
 315static int svc_pool_map_get_node(unsigned int pidx)
 316{
 317	const struct svc_pool_map *m = &svc_pool_map;
 318
 319	if (m->count) {
 320		if (m->mode == SVC_POOL_PERCPU)
 321			return cpu_to_node(m->pool_to[pidx]);
 322		if (m->mode == SVC_POOL_PERNODE)
 323			return m->pool_to[pidx];
 324	}
 325	return NUMA_NO_NODE;
 326}
 327/*
 328 * Set the given thread's cpus_allowed mask so that it
 329 * will only run on cpus in the given pool.
 330 */
 331static inline void
 332svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
 333{
 334	struct svc_pool_map *m = &svc_pool_map;
 335	unsigned int node = m->pool_to[pidx];
 336
 337	/*
 338	 * The caller checks for sv_nrpools > 1, which
 339	 * implies that we've been initialized.
 340	 */
 341	WARN_ON_ONCE(m->count == 0);
 342	if (m->count == 0)
 343		return;
 344
 345	switch (m->mode) {
 346	case SVC_POOL_PERCPU:
 347	{
 348		set_cpus_allowed_ptr(task, cpumask_of(node));
 349		break;
 350	}
 351	case SVC_POOL_PERNODE:
 352	{
 353		set_cpus_allowed_ptr(task, cpumask_of_node(node));
 354		break;
 355	}
 356	}
 357}
 358
 359/**
 360 * svc_pool_for_cpu - Select pool to run a thread on this cpu
 361 * @serv: An RPC service
 362 *
 363 * Use the active CPU and the svc_pool_map's mode setting to
 364 * select the svc thread pool to use. Once initialized, the
 365 * svc_pool_map does not change.
 366 *
 367 * Return value:
 368 *   A pointer to an svc_pool
 369 */
 370struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv)
 
 371{
 372	struct svc_pool_map *m = &svc_pool_map;
 373	int cpu = raw_smp_processor_id();
 374	unsigned int pidx = 0;
 375
 376	if (serv->sv_nrpools <= 1)
 377		return serv->sv_pools;
 378
 379	switch (m->mode) {
 380	case SVC_POOL_PERCPU:
 381		pidx = m->to_pool[cpu];
 382		break;
 383	case SVC_POOL_PERNODE:
 384		pidx = m->to_pool[cpu_to_node(cpu)];
 385		break;
 
 
 
 
 386	}
 387
 388	return &serv->sv_pools[pidx % serv->sv_nrpools];
 389}
 390
 391int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
 392{
 393	int err;
 394
 395	err = rpcb_create_local(net);
 396	if (err)
 397		return err;
 398
 399	/* Remove any stale portmap registrations */
 400	svc_unregister(serv, net);
 401	return 0;
 402}
 403EXPORT_SYMBOL_GPL(svc_rpcb_setup);
 404
 405void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
 406{
 407	svc_unregister(serv, net);
 408	rpcb_put_local(net);
 409}
 410EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
 411
 412static int svc_uses_rpcbind(struct svc_serv *serv)
 413{
 414	struct svc_program	*progp;
 415	unsigned int		i;
 416
 417	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 418		for (i = 0; i < progp->pg_nvers; i++) {
 419			if (progp->pg_vers[i] == NULL)
 420				continue;
 421			if (!progp->pg_vers[i]->vs_hidden)
 422				return 1;
 423		}
 424	}
 425
 426	return 0;
 427}
 428
 429int svc_bind(struct svc_serv *serv, struct net *net)
 430{
 431	if (!svc_uses_rpcbind(serv))
 432		return 0;
 433	return svc_rpcb_setup(serv, net);
 434}
 435EXPORT_SYMBOL_GPL(svc_bind);
 436
 437#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 438static void
 439__svc_init_bc(struct svc_serv *serv)
 440{
 441	INIT_LIST_HEAD(&serv->sv_cb_list);
 442	spin_lock_init(&serv->sv_cb_lock);
 443	init_waitqueue_head(&serv->sv_cb_waitq);
 444}
 445#else
 446static void
 447__svc_init_bc(struct svc_serv *serv)
 448{
 449}
 450#endif
 451
 452/*
 453 * Create an RPC service
 454 */
 455static struct svc_serv *
 456__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 457	     int (*threadfn)(void *data))
 458{
 459	struct svc_serv	*serv;
 460	unsigned int vers;
 461	unsigned int xdrsize;
 462	unsigned int i;
 463
 464	if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
 465		return NULL;
 466	serv->sv_name      = prog->pg_name;
 467	serv->sv_program   = prog;
 468	kref_init(&serv->sv_refcnt);
 469	serv->sv_stats     = prog->pg_stats;
 470	if (bufsize > RPCSVC_MAXPAYLOAD)
 471		bufsize = RPCSVC_MAXPAYLOAD;
 472	serv->sv_max_payload = bufsize? bufsize : 4096;
 473	serv->sv_max_mesg  = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
 474	serv->sv_threadfn = threadfn;
 475	xdrsize = 0;
 476	while (prog) {
 477		prog->pg_lovers = prog->pg_nvers-1;
 478		for (vers=0; vers<prog->pg_nvers ; vers++)
 479			if (prog->pg_vers[vers]) {
 480				prog->pg_hivers = vers;
 481				if (prog->pg_lovers > vers)
 482					prog->pg_lovers = vers;
 483				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
 484					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
 485			}
 486		prog = prog->pg_next;
 487	}
 488	serv->sv_xdrsize   = xdrsize;
 489	INIT_LIST_HEAD(&serv->sv_tempsocks);
 490	INIT_LIST_HEAD(&serv->sv_permsocks);
 491	timer_setup(&serv->sv_temptimer, NULL, 0);
 492	spin_lock_init(&serv->sv_lock);
 493
 494	__svc_init_bc(serv);
 495
 496	serv->sv_nrpools = npools;
 497	serv->sv_pools =
 498		kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
 499			GFP_KERNEL);
 500	if (!serv->sv_pools) {
 501		kfree(serv);
 502		return NULL;
 503	}
 504
 505	for (i = 0; i < serv->sv_nrpools; i++) {
 506		struct svc_pool *pool = &serv->sv_pools[i];
 507
 508		dprintk("svc: initialising pool %u for %s\n",
 509				i, serv->sv_name);
 510
 511		pool->sp_id = i;
 
 512		INIT_LIST_HEAD(&pool->sp_sockets);
 513		INIT_LIST_HEAD(&pool->sp_all_threads);
 514		spin_lock_init(&pool->sp_lock);
 515	}
 516
 
 
 
 517	return serv;
 518}
 519
 520/**
 521 * svc_create - Create an RPC service
 522 * @prog: the RPC program the new service will handle
 523 * @bufsize: maximum message size for @prog
 524 * @threadfn: a function to service RPC requests for @prog
 525 *
 526 * Returns an instantiated struct svc_serv object or NULL.
 527 */
 528struct svc_serv *svc_create(struct svc_program *prog, unsigned int bufsize,
 529			    int (*threadfn)(void *data))
 530{
 531	return __svc_create(prog, bufsize, 1, threadfn);
 532}
 533EXPORT_SYMBOL_GPL(svc_create);
 534
 535/**
 536 * svc_create_pooled - Create an RPC service with pooled threads
 537 * @prog: the RPC program the new service will handle
 538 * @bufsize: maximum message size for @prog
 539 * @threadfn: a function to service RPC requests for @prog
 540 *
 541 * Returns an instantiated struct svc_serv object or NULL.
 542 */
 543struct svc_serv *svc_create_pooled(struct svc_program *prog,
 544				   unsigned int bufsize,
 545				   int (*threadfn)(void *data))
 546{
 547	struct svc_serv *serv;
 548	unsigned int npools = svc_pool_map_get();
 549
 550	serv = __svc_create(prog, bufsize, npools, threadfn);
 551	if (!serv)
 552		goto out_err;
 
 
 
 
 553	return serv;
 554out_err:
 555	svc_pool_map_put(npools);
 556	return NULL;
 557}
 558EXPORT_SYMBOL_GPL(svc_create_pooled);
 559
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 560/*
 561 * Destroy an RPC service. Should be called with appropriate locking to
 562 * protect sv_permsocks and sv_tempsocks.
 563 */
 564void
 565svc_destroy(struct kref *ref)
 566{
 567	struct svc_serv *serv = container_of(ref, struct svc_serv, sv_refcnt);
 
 
 
 
 
 
 
 
 
 
 568
 569	dprintk("svc: svc_destroy(%s)\n", serv->sv_program->pg_name);
 570	timer_shutdown_sync(&serv->sv_temptimer);
 571
 572	/*
 573	 * The last user is gone and thus all sockets have to be destroyed to
 574	 * the point. Check this.
 575	 */
 576	BUG_ON(!list_empty(&serv->sv_permsocks));
 577	BUG_ON(!list_empty(&serv->sv_tempsocks));
 578
 579	cache_clean_deferred(serv);
 580
 581	svc_pool_map_put(serv->sv_nrpools);
 
 582
 583	kfree(serv->sv_pools);
 584	kfree(serv);
 585}
 586EXPORT_SYMBOL_GPL(svc_destroy);
 587
 588/*
 589 * Allocate an RPC server's buffer space.
 590 * We allocate pages and place them in rq_pages.
 591 */
 592static int
 593svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
 594{
 595	unsigned int pages, arghi;
 596
 597	/* bc_xprt uses fore channel allocated buffers */
 598	if (svc_is_backchannel(rqstp))
 599		return 1;
 600
 601	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 602				       * We assume one is at most one page
 603				       */
 604	arghi = 0;
 605	WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
 606	if (pages > RPCSVC_MAXPAGES)
 607		pages = RPCSVC_MAXPAGES;
 608	while (pages) {
 609		struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
 610		if (!p)
 611			break;
 612		rqstp->rq_pages[arghi++] = p;
 613		pages--;
 614	}
 615	return pages == 0;
 616}
 617
 618/*
 619 * Release an RPC server buffer
 620 */
 621static void
 622svc_release_buffer(struct svc_rqst *rqstp)
 623{
 624	unsigned int i;
 625
 626	for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
 627		if (rqstp->rq_pages[i])
 628			put_page(rqstp->rq_pages[i]);
 629}
 630
 631struct svc_rqst *
 632svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
 633{
 634	struct svc_rqst	*rqstp;
 635
 636	rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
 637	if (!rqstp)
 638		return rqstp;
 639
 640	__set_bit(RQ_BUSY, &rqstp->rq_flags);
 
 
 
 
 
 
 641	rqstp->rq_server = serv;
 642	rqstp->rq_pool = pool;
 643
 644	rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0);
 645	if (!rqstp->rq_scratch_page)
 646		goto out_enomem;
 647
 648	rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 649	if (!rqstp->rq_argp)
 650		goto out_enomem;
 651
 652	rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 653	if (!rqstp->rq_resp)
 654		goto out_enomem;
 655
 656	if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
 657		goto out_enomem;
 658
 659	return rqstp;
 
 
 660out_enomem:
 661	svc_rqst_free(rqstp);
 662	return NULL;
 663}
 664EXPORT_SYMBOL_GPL(svc_rqst_alloc);
 665
 666static struct svc_rqst *
 667svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
 668{
 669	struct svc_rqst	*rqstp;
 670
 671	rqstp = svc_rqst_alloc(serv, pool, node);
 672	if (!rqstp)
 673		return ERR_PTR(-ENOMEM);
 674
 675	svc_get(serv);
 676	spin_lock_bh(&serv->sv_lock);
 677	serv->sv_nrthreads += 1;
 678	spin_unlock_bh(&serv->sv_lock);
 679
 680	spin_lock_bh(&pool->sp_lock);
 681	pool->sp_nrthreads++;
 682	list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
 683	spin_unlock_bh(&pool->sp_lock);
 684	return rqstp;
 685}
 
 686
 687/*
 688 * Choose a pool in which to create a new thread, for svc_set_num_threads
 689 */
 690static inline struct svc_pool *
 691choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 692{
 693	if (pool != NULL)
 694		return pool;
 695
 696	return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
 697}
 698
 699/*
 700 * Choose a thread to kill, for svc_set_num_threads
 701 */
 702static inline struct task_struct *
 703choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 704{
 705	unsigned int i;
 706	struct task_struct *task = NULL;
 707
 708	if (pool != NULL) {
 709		spin_lock_bh(&pool->sp_lock);
 710	} else {
 711		/* choose a pool in round-robin fashion */
 712		for (i = 0; i < serv->sv_nrpools; i++) {
 713			pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
 714			spin_lock_bh(&pool->sp_lock);
 715			if (!list_empty(&pool->sp_all_threads))
 716				goto found_pool;
 717			spin_unlock_bh(&pool->sp_lock);
 718		}
 719		return NULL;
 720	}
 721
 722found_pool:
 723	if (!list_empty(&pool->sp_all_threads)) {
 724		struct svc_rqst *rqstp;
 725
 726		/*
 727		 * Remove from the pool->sp_all_threads list
 728		 * so we don't try to kill it again.
 729		 */
 730		rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
 731		set_bit(RQ_VICTIM, &rqstp->rq_flags);
 732		list_del_rcu(&rqstp->rq_all);
 733		task = rqstp->rq_task;
 734	}
 735	spin_unlock_bh(&pool->sp_lock);
 736
 737	return task;
 738}
 739
 740/* create new threads */
 741static int
 742svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 
 
 
 
 
 
 
 
 
 
 
 
 
 743{
 744	struct svc_rqst	*rqstp;
 745	struct task_struct *task;
 746	struct svc_pool *chosen_pool;
 
 747	unsigned int state = serv->sv_nrthreads-1;
 748	int node;
 749
 750	do {
 
 
 
 
 
 
 
 
 
 
 751		nrservs--;
 752		chosen_pool = choose_pool(serv, pool, &state);
 753
 754		node = svc_pool_map_get_node(chosen_pool->sp_id);
 755		rqstp = svc_prepare_thread(serv, chosen_pool, node);
 756		if (IS_ERR(rqstp))
 757			return PTR_ERR(rqstp);
 
 
 758
 759		task = kthread_create_on_node(serv->sv_threadfn, rqstp,
 760					      node, "%s", serv->sv_name);
 
 761		if (IS_ERR(task)) {
 
 
 762			svc_exit_thread(rqstp);
 763			return PTR_ERR(task);
 764		}
 765
 766		rqstp->rq_task = task;
 767		if (serv->sv_nrpools > 1)
 768			svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
 769
 770		svc_sock_update_bufs(serv);
 771		wake_up_process(task);
 772	} while (nrservs > 0);
 773
 774	return 0;
 775}
 776
 777/*
 778 * Create or destroy enough new threads to make the number
 779 * of threads the given number.  If `pool' is non-NULL, applies
 780 * only to threads in that pool, otherwise round-robins between
 781 * all pools.  Caller must ensure that mutual exclusion between this and
 782 * server startup or shutdown.
 783 */
 784
 785/* destroy old threads */
 786static int
 787svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 788{
 789	struct task_struct *task;
 790	unsigned int state = serv->sv_nrthreads-1;
 791
 792	/* destroy old threads */
 793	do {
 794		task = choose_victim(serv, pool, &state);
 795		if (task == NULL)
 796			break;
 797		kthread_stop(task);
 798		nrservs++;
 799	} while (nrservs < 0);
 800	return 0;
 801}
 802
 803int
 804svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 805{
 806	if (pool == NULL) {
 807		nrservs -= serv->sv_nrthreads;
 808	} else {
 809		spin_lock_bh(&pool->sp_lock);
 810		nrservs -= pool->sp_nrthreads;
 811		spin_unlock_bh(&pool->sp_lock);
 812	}
 813
 814	if (nrservs > 0)
 815		return svc_start_kthreads(serv, pool, nrservs);
 816	if (nrservs < 0)
 817		return svc_stop_kthreads(serv, pool, nrservs);
 818	return 0;
 819}
 820EXPORT_SYMBOL_GPL(svc_set_num_threads);
 821
 822/**
 823 * svc_rqst_replace_page - Replace one page in rq_pages[]
 824 * @rqstp: svc_rqst with pages to replace
 825 * @page: replacement page
 826 *
 827 * When replacing a page in rq_pages, batch the release of the
 828 * replaced pages to avoid hammering the page allocator.
 829 */
 830void svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page)
 831{
 832	if (*rqstp->rq_next_page) {
 833		if (!pagevec_space(&rqstp->rq_pvec))
 834			__pagevec_release(&rqstp->rq_pvec);
 835		pagevec_add(&rqstp->rq_pvec, *rqstp->rq_next_page);
 836	}
 837
 838	get_page(page);
 839	*(rqstp->rq_next_page++) = page;
 840}
 841EXPORT_SYMBOL_GPL(svc_rqst_replace_page);
 842
 843/*
 844 * Called from a server thread as it's exiting. Caller must hold the "service
 845 * mutex" for the service.
 846 */
 847void
 848svc_rqst_free(struct svc_rqst *rqstp)
 849{
 
 
 
 850	svc_release_buffer(rqstp);
 851	if (rqstp->rq_scratch_page)
 852		put_page(rqstp->rq_scratch_page);
 853	kfree(rqstp->rq_resp);
 854	kfree(rqstp->rq_argp);
 855	kfree(rqstp->rq_auth_data);
 856	kfree_rcu(rqstp, rq_rcu_head);
 857}
 858EXPORT_SYMBOL_GPL(svc_rqst_free);
 859
 860void
 861svc_exit_thread(struct svc_rqst *rqstp)
 862{
 863	struct svc_serv	*serv = rqstp->rq_server;
 864	struct svc_pool	*pool = rqstp->rq_pool;
 865
 866	spin_lock_bh(&pool->sp_lock);
 867	pool->sp_nrthreads--;
 868	if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
 869		list_del_rcu(&rqstp->rq_all);
 870	spin_unlock_bh(&pool->sp_lock);
 871
 872	spin_lock_bh(&serv->sv_lock);
 873	serv->sv_nrthreads -= 1;
 874	spin_unlock_bh(&serv->sv_lock);
 875	svc_sock_update_bufs(serv);
 876
 877	svc_rqst_free(rqstp);
 878
 879	svc_put(serv);
 
 
 880}
 881EXPORT_SYMBOL_GPL(svc_exit_thread);
 882
 883/*
 884 * Register an "inet" protocol family netid with the local
 885 * rpcbind daemon via an rpcbind v4 SET request.
 886 *
 887 * No netconfig infrastructure is available in the kernel, so
 888 * we map IP_ protocol numbers to netids by hand.
 889 *
 890 * Returns zero on success; a negative errno value is returned
 891 * if any error occurs.
 892 */
 893static int __svc_rpcb_register4(struct net *net, const u32 program,
 894				const u32 version,
 895				const unsigned short protocol,
 896				const unsigned short port)
 897{
 898	const struct sockaddr_in sin = {
 899		.sin_family		= AF_INET,
 900		.sin_addr.s_addr	= htonl(INADDR_ANY),
 901		.sin_port		= htons(port),
 902	};
 903	const char *netid;
 904	int error;
 905
 906	switch (protocol) {
 907	case IPPROTO_UDP:
 908		netid = RPCBIND_NETID_UDP;
 909		break;
 910	case IPPROTO_TCP:
 911		netid = RPCBIND_NETID_TCP;
 912		break;
 913	default:
 914		return -ENOPROTOOPT;
 915	}
 916
 917	error = rpcb_v4_register(net, program, version,
 918					(const struct sockaddr *)&sin, netid);
 919
 920	/*
 921	 * User space didn't support rpcbind v4, so retry this
 922	 * registration request with the legacy rpcbind v2 protocol.
 923	 */
 924	if (error == -EPROTONOSUPPORT)
 925		error = rpcb_register(net, program, version, protocol, port);
 926
 927	return error;
 928}
 929
 930#if IS_ENABLED(CONFIG_IPV6)
 931/*
 932 * Register an "inet6" protocol family netid with the local
 933 * rpcbind daemon via an rpcbind v4 SET request.
 934 *
 935 * No netconfig infrastructure is available in the kernel, so
 936 * we map IP_ protocol numbers to netids by hand.
 937 *
 938 * Returns zero on success; a negative errno value is returned
 939 * if any error occurs.
 940 */
 941static int __svc_rpcb_register6(struct net *net, const u32 program,
 942				const u32 version,
 943				const unsigned short protocol,
 944				const unsigned short port)
 945{
 946	const struct sockaddr_in6 sin6 = {
 947		.sin6_family		= AF_INET6,
 948		.sin6_addr		= IN6ADDR_ANY_INIT,
 949		.sin6_port		= htons(port),
 950	};
 951	const char *netid;
 952	int error;
 953
 954	switch (protocol) {
 955	case IPPROTO_UDP:
 956		netid = RPCBIND_NETID_UDP6;
 957		break;
 958	case IPPROTO_TCP:
 959		netid = RPCBIND_NETID_TCP6;
 960		break;
 961	default:
 962		return -ENOPROTOOPT;
 963	}
 964
 965	error = rpcb_v4_register(net, program, version,
 966					(const struct sockaddr *)&sin6, netid);
 967
 968	/*
 969	 * User space didn't support rpcbind version 4, so we won't
 970	 * use a PF_INET6 listener.
 971	 */
 972	if (error == -EPROTONOSUPPORT)
 973		error = -EAFNOSUPPORT;
 974
 975	return error;
 976}
 977#endif	/* IS_ENABLED(CONFIG_IPV6) */
 978
 979/*
 980 * Register a kernel RPC service via rpcbind version 4.
 981 *
 982 * Returns zero on success; a negative errno value is returned
 983 * if any error occurs.
 984 */
 985static int __svc_register(struct net *net, const char *progname,
 986			  const u32 program, const u32 version,
 987			  const int family,
 988			  const unsigned short protocol,
 989			  const unsigned short port)
 990{
 991	int error = -EAFNOSUPPORT;
 992
 993	switch (family) {
 994	case PF_INET:
 995		error = __svc_rpcb_register4(net, program, version,
 996						protocol, port);
 997		break;
 998#if IS_ENABLED(CONFIG_IPV6)
 999	case PF_INET6:
1000		error = __svc_rpcb_register6(net, program, version,
1001						protocol, port);
1002#endif
1003	}
1004
1005	trace_svc_register(progname, version, protocol, port, family, error);
 
 
1006	return error;
1007}
1008
1009int svc_rpcbind_set_version(struct net *net,
1010			    const struct svc_program *progp,
1011			    u32 version, int family,
1012			    unsigned short proto,
1013			    unsigned short port)
1014{
1015	return __svc_register(net, progp->pg_name, progp->pg_prog,
1016				version, family, proto, port);
1017
1018}
1019EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
1020
1021int svc_generic_rpcbind_set(struct net *net,
1022			    const struct svc_program *progp,
1023			    u32 version, int family,
1024			    unsigned short proto,
1025			    unsigned short port)
1026{
1027	const struct svc_version *vers = progp->pg_vers[version];
1028	int error;
1029
1030	if (vers == NULL)
1031		return 0;
1032
1033	if (vers->vs_hidden) {
1034		trace_svc_noregister(progp->pg_name, version, proto,
1035				     port, family, 0);
1036		return 0;
1037	}
1038
1039	/*
1040	 * Don't register a UDP port if we need congestion
1041	 * control.
1042	 */
1043	if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
1044		return 0;
1045
1046	error = svc_rpcbind_set_version(net, progp, version,
1047					family, proto, port);
1048
1049	return (vers->vs_rpcb_optnl) ? 0 : error;
1050}
1051EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
1052
1053/**
1054 * svc_register - register an RPC service with the local portmapper
1055 * @serv: svc_serv struct for the service to register
1056 * @net: net namespace for the service to register
1057 * @family: protocol family of service's listener socket
1058 * @proto: transport protocol number to advertise
1059 * @port: port to advertise
1060 *
1061 * Service is registered for any address in the passed-in protocol family
1062 */
1063int svc_register(const struct svc_serv *serv, struct net *net,
1064		 const int family, const unsigned short proto,
1065		 const unsigned short port)
1066{
1067	struct svc_program	*progp;
1068	unsigned int		i;
1069	int			error = 0;
1070
1071	WARN_ON_ONCE(proto == 0 && port == 0);
1072	if (proto == 0 && port == 0)
1073		return -EINVAL;
1074
1075	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1076		for (i = 0; i < progp->pg_nvers; i++) {
 
 
1077
1078			error = progp->pg_rpcbind_set(net, progp, i,
1079					family, proto, port);
1080			if (error < 0) {
1081				printk(KERN_WARNING "svc: failed to register "
1082					"%sv%u RPC service (errno %d).\n",
1083					progp->pg_name, i, -error);
 
 
 
 
 
 
 
 
 
1084				break;
1085			}
1086		}
1087	}
1088
1089	return error;
1090}
1091
1092/*
1093 * If user space is running rpcbind, it should take the v4 UNSET
1094 * and clear everything for this [program, version].  If user space
1095 * is running portmap, it will reject the v4 UNSET, but won't have
1096 * any "inet6" entries anyway.  So a PMAP_UNSET should be sufficient
1097 * in this case to clear all existing entries for [program, version].
1098 */
1099static void __svc_unregister(struct net *net, const u32 program, const u32 version,
1100			     const char *progname)
1101{
1102	int error;
1103
1104	error = rpcb_v4_register(net, program, version, NULL, "");
1105
1106	/*
1107	 * User space didn't support rpcbind v4, so retry this
1108	 * request with the legacy rpcbind v2 protocol.
1109	 */
1110	if (error == -EPROTONOSUPPORT)
1111		error = rpcb_register(net, program, version, 0, 0);
1112
1113	trace_svc_unregister(progname, version, error);
 
1114}
1115
1116/*
1117 * All netids, bind addresses and ports registered for [program, version]
1118 * are removed from the local rpcbind database (if the service is not
1119 * hidden) to make way for a new instance of the service.
1120 *
1121 * The result of unregistration is reported via dprintk for those who want
1122 * verification of the result, but is otherwise not important.
1123 */
1124static void svc_unregister(const struct svc_serv *serv, struct net *net)
1125{
1126	struct svc_program *progp;
1127	unsigned long flags;
1128	unsigned int i;
1129
1130	clear_thread_flag(TIF_SIGPENDING);
1131
1132	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1133		for (i = 0; i < progp->pg_nvers; i++) {
1134			if (progp->pg_vers[i] == NULL)
1135				continue;
1136			if (progp->pg_vers[i]->vs_hidden)
1137				continue;
 
 
 
1138			__svc_unregister(net, progp->pg_prog, i, progp->pg_name);
1139		}
1140	}
1141
1142	spin_lock_irqsave(&current->sighand->siglock, flags);
1143	recalc_sigpending();
1144	spin_unlock_irqrestore(&current->sighand->siglock, flags);
1145}
1146
1147/*
1148 * dprintk the given error with the address of the client that caused it.
1149 */
1150#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1151static __printf(2, 3)
1152void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
1153{
1154	struct va_format vaf;
1155	va_list args;
1156	char 	buf[RPC_MAX_ADDRBUFLEN];
1157
1158	va_start(args, fmt);
1159
1160	vaf.fmt = fmt;
1161	vaf.va = &args;
1162
1163	dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
 
1164
1165	va_end(args);
1166}
1167#else
1168static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
1169#endif
1170
1171__be32
1172svc_generic_init_request(struct svc_rqst *rqstp,
1173		const struct svc_program *progp,
1174		struct svc_process_info *ret)
1175{
1176	const struct svc_version *versp = NULL;	/* compiler food */
1177	const struct svc_procedure *procp = NULL;
1178
1179	if (rqstp->rq_vers >= progp->pg_nvers )
1180		goto err_bad_vers;
1181	versp = progp->pg_vers[rqstp->rq_vers];
1182	if (!versp)
1183		goto err_bad_vers;
1184
1185	/*
1186	 * Some protocol versions (namely NFSv4) require some form of
1187	 * congestion control.  (See RFC 7530 section 3.1 paragraph 2)
1188	 * In other words, UDP is not allowed. We mark those when setting
1189	 * up the svc_xprt, and verify that here.
1190	 *
1191	 * The spec is not very clear about what error should be returned
1192	 * when someone tries to access a server that is listening on UDP
1193	 * for lower versions. RPC_PROG_MISMATCH seems to be the closest
1194	 * fit.
1195	 */
1196	if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
1197	    !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
1198		goto err_bad_vers;
1199
1200	if (rqstp->rq_proc >= versp->vs_nproc)
1201		goto err_bad_proc;
1202	rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
1203	if (!procp)
1204		goto err_bad_proc;
1205
1206	/* Initialize storage for argp and resp */
1207	memset(rqstp->rq_argp, 0, procp->pc_argzero);
1208	memset(rqstp->rq_resp, 0, procp->pc_ressize);
1209
1210	/* Bump per-procedure stats counter */
1211	versp->vs_count[rqstp->rq_proc]++;
1212
1213	ret->dispatch = versp->vs_dispatch;
1214	return rpc_success;
1215err_bad_vers:
1216	ret->mismatch.lovers = progp->pg_lovers;
1217	ret->mismatch.hivers = progp->pg_hivers;
1218	return rpc_prog_mismatch;
1219err_bad_proc:
1220	return rpc_proc_unavail;
1221}
1222EXPORT_SYMBOL_GPL(svc_generic_init_request);
1223
1224/*
1225 * Common routine for processing the RPC request.
1226 */
1227static int
1228svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
1229{
1230	struct svc_program	*progp;
1231	const struct svc_procedure *procp = NULL;
 
1232	struct svc_serv		*serv = rqstp->rq_server;
1233	struct svc_process_info process;
1234	__be32			*statp;
1235	u32			prog, vers;
1236	__be32			rpc_stat;
1237	int			auth_res, rc;
1238	__be32			*reply_statp;
1239
1240	rpc_stat = rpc_success;
1241
1242	if (argv->iov_len < 6*4)
1243		goto err_short_len;
1244
1245	/* Will be turned off by GSS integrity and privacy services */
1246	set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
1247	/* Will be turned off only when NFSv4 Sessions are used */
1248	set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
1249	clear_bit(RQ_DROPME, &rqstp->rq_flags);
 
 
 
1250
1251	svc_putu32(resv, rqstp->rq_xid);
1252
1253	vers = svc_getnl(argv);
1254
1255	/* First words of reply: */
1256	svc_putnl(resv, 1);		/* REPLY */
1257
1258	if (vers != 2)		/* RPC version number */
1259		goto err_bad_rpc;
1260
1261	/* Save position in case we later decide to reject: */
1262	reply_statp = resv->iov_base + resv->iov_len;
1263
1264	svc_putnl(resv, 0);		/* ACCEPT */
1265
1266	rqstp->rq_prog = prog = svc_getnl(argv);	/* program number */
1267	rqstp->rq_vers = svc_getnl(argv);	/* version number */
1268	rqstp->rq_proc = svc_getnl(argv);	/* procedure number */
 
 
1269
1270	for (progp = serv->sv_program; progp; progp = progp->pg_next)
1271		if (prog == progp->pg_prog)
1272			break;
1273
1274	/*
1275	 * Decode auth data, and add verifier to reply buffer.
1276	 * We do this before anything else in order to get a decent
1277	 * auth verifier.
1278	 */
1279	auth_res = svc_authenticate(rqstp);
1280	/* Also give the program a chance to reject this call: */
1281	if (auth_res == SVC_OK && progp)
 
1282		auth_res = progp->pg_authenticate(rqstp);
1283	trace_svc_authenticate(rqstp, auth_res);
1284	switch (auth_res) {
1285	case SVC_OK:
1286		break;
1287	case SVC_GARBAGE:
1288		goto err_garbage;
1289	case SVC_SYSERR:
1290		rpc_stat = rpc_system_err;
1291		goto err_bad;
1292	case SVC_DENIED:
1293		goto err_bad_auth;
1294	case SVC_CLOSE:
1295		goto close;
 
1296	case SVC_DROP:
1297		goto dropit;
1298	case SVC_COMPLETE:
1299		goto sendit;
1300	}
1301
1302	if (progp == NULL)
1303		goto err_bad_prog;
1304
1305	rpc_stat = progp->pg_init_request(rqstp, progp, &process);
1306	switch (rpc_stat) {
1307	case rpc_success:
1308		break;
1309	case rpc_prog_unavail:
1310		goto err_bad_prog;
1311	case rpc_prog_mismatch:
1312		goto err_bad_vers;
1313	case rpc_proc_unavail:
1314		goto err_bad_proc;
1315	}
1316
1317	procp = rqstp->rq_procinfo;
1318	/* Should this check go into the dispatcher? */
1319	if (!procp || !procp->pc_func)
1320		goto err_bad_proc;
 
1321
1322	/* Syntactic check complete */
1323	serv->sv_stats->rpccnt++;
1324	trace_svc_process(rqstp, progp->pg_name);
1325
1326	/* Build the reply header. */
1327	statp = resv->iov_base +resv->iov_len;
1328	svc_putnl(resv, RPC_SUCCESS);
1329
 
 
 
 
 
 
 
1330	/* un-reserve some of the out-queue now that we have a
1331	 * better idea of reply size
1332	 */
1333	if (procp->pc_xdrressize)
1334		svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1335
1336	/* Call the function that processes the request. */
1337	rc = process.dispatch(rqstp, statp);
1338	if (procp->pc_release)
1339		procp->pc_release(rqstp);
1340	if (!rc)
1341		goto dropit;
1342	if (rqstp->rq_auth_stat != rpc_auth_ok)
1343		goto err_bad_auth;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1344
1345	/* Check RPC status result */
1346	if (*statp != rpc_success)
1347		resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
1348
 
 
 
 
1349	if (procp->pc_encode == NULL)
1350		goto dropit;
1351
1352 sendit:
1353	if (svc_authorise(rqstp))
1354		goto close_xprt;
1355	return 1;		/* Caller can now send it */
1356
1357 dropit:
1358	svc_authorise(rqstp);	/* doesn't hurt to call this twice */
1359	dprintk("svc: svc_process dropit\n");
1360	return 0;
1361
1362 close:
1363	svc_authorise(rqstp);
1364close_xprt:
1365	if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1366		svc_xprt_close(rqstp->rq_xprt);
1367	dprintk("svc: svc_process close\n");
1368	return 0;
1369
1370err_short_len:
1371	svc_printk(rqstp, "short len %zd, dropping request\n",
1372			argv->iov_len);
1373	goto close_xprt;
 
1374
1375err_bad_rpc:
1376	serv->sv_stats->rpcbadfmt++;
1377	svc_putnl(resv, 1);	/* REJECT */
1378	svc_putnl(resv, 0);	/* RPC_MISMATCH */
1379	svc_putnl(resv, 2);	/* Only RPCv2 supported */
1380	svc_putnl(resv, 2);
1381	goto sendit;
1382
1383err_bad_auth:
1384	dprintk("svc: authentication failed (%d)\n",
1385		be32_to_cpu(rqstp->rq_auth_stat));
1386	serv->sv_stats->rpcbadauth++;
1387	/* Restore write pointer to location of accept status: */
1388	xdr_ressize_check(rqstp, reply_statp);
1389	svc_putnl(resv, 1);	/* REJECT */
1390	svc_putnl(resv, 1);	/* AUTH_ERROR */
1391	svc_putu32(resv, rqstp->rq_auth_stat);	/* status */
1392	goto sendit;
1393
1394err_bad_prog:
1395	dprintk("svc: unknown program %d\n", prog);
1396	serv->sv_stats->rpcbadfmt++;
1397	svc_putnl(resv, RPC_PROG_UNAVAIL);
1398	goto sendit;
1399
1400err_bad_vers:
1401	svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1402		       rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
1403
1404	serv->sv_stats->rpcbadfmt++;
1405	svc_putnl(resv, RPC_PROG_MISMATCH);
1406	svc_putnl(resv, process.mismatch.lovers);
1407	svc_putnl(resv, process.mismatch.hivers);
1408	goto sendit;
1409
1410err_bad_proc:
1411	svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
1412
1413	serv->sv_stats->rpcbadfmt++;
1414	svc_putnl(resv, RPC_PROC_UNAVAIL);
1415	goto sendit;
1416
1417err_garbage:
1418	svc_printk(rqstp, "failed to decode args\n");
1419
1420	rpc_stat = rpc_garbage_args;
1421err_bad:
1422	serv->sv_stats->rpcbadfmt++;
1423	svc_putnl(resv, ntohl(rpc_stat));
1424	goto sendit;
1425}
 
1426
1427/*
1428 * Process the RPC request.
1429 */
1430int
1431svc_process(struct svc_rqst *rqstp)
1432{
1433	struct kvec		*argv = &rqstp->rq_arg.head[0];
1434	struct kvec		*resv = &rqstp->rq_res.head[0];
1435	__be32			dir;
1436
1437#if IS_ENABLED(CONFIG_FAIL_SUNRPC)
1438	if (!fail_sunrpc.ignore_server_disconnect &&
1439	    should_fail(&fail_sunrpc.attr, 1))
1440		svc_xprt_deferred_close(rqstp->rq_xprt);
1441#endif
1442
1443	/*
1444	 * Setup response xdr_buf.
1445	 * Initially it has just one page
1446	 */
1447	rqstp->rq_next_page = &rqstp->rq_respages[1];
1448	resv->iov_base = page_address(rqstp->rq_respages[0]);
1449	resv->iov_len = 0;
1450	rqstp->rq_res.pages = rqstp->rq_next_page;
1451	rqstp->rq_res.len = 0;
1452	rqstp->rq_res.page_base = 0;
1453	rqstp->rq_res.page_len = 0;
1454	rqstp->rq_res.buflen = PAGE_SIZE;
1455	rqstp->rq_res.tail[0].iov_base = NULL;
1456	rqstp->rq_res.tail[0].iov_len = 0;
1457
1458	dir = svc_getu32(argv);
1459	if (dir != rpc_call)
1460		goto out_baddir;
1461	if (!svc_process_common(rqstp, argv, resv))
1462		goto out_drop;
1463	return svc_send(rqstp);
1464
1465out_baddir:
1466	svc_printk(rqstp, "bad direction 0x%08x, dropping request\n",
1467		   be32_to_cpu(dir));
1468	rqstp->rq_server->sv_stats->rpcbadfmt++;
1469out_drop:
1470	svc_drop(rqstp);
1471	return 0;
 
 
 
 
1472}
1473EXPORT_SYMBOL_GPL(svc_process);
1474
1475#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1476/*
1477 * Process a backchannel RPC request that arrived over an existing
1478 * outbound connection
1479 */
1480int
1481bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
1482	       struct svc_rqst *rqstp)
1483{
1484	struct kvec	*argv = &rqstp->rq_arg.head[0];
1485	struct kvec	*resv = &rqstp->rq_res.head[0];
1486	struct rpc_task *task;
1487	int proc_error;
1488	int error;
1489
1490	dprintk("svc: %s(%p)\n", __func__, req);
1491
1492	/* Build the svc_rqst used by the common processing routine */
 
1493	rqstp->rq_xid = req->rq_xid;
1494	rqstp->rq_prot = req->rq_xprt->prot;
1495	rqstp->rq_server = serv;
1496	rqstp->rq_bc_net = req->rq_xprt->xprt_net;
1497
1498	rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1499	memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1500	memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1501	memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1502
1503	/* Adjust the argument buffer length */
1504	rqstp->rq_arg.len = req->rq_private_buf.len;
1505	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1506		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1507		rqstp->rq_arg.page_len = 0;
1508	} else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
1509			rqstp->rq_arg.page_len)
1510		rqstp->rq_arg.page_len = rqstp->rq_arg.len -
1511			rqstp->rq_arg.head[0].iov_len;
1512	else
1513		rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
1514			rqstp->rq_arg.page_len;
1515
1516	/* reset result send buffer "put" position */
1517	resv->iov_len = 0;
1518
 
 
 
 
 
1519	/*
1520	 * Skip the next two words because they've already been
1521	 * processed in the transport
1522	 */
1523	svc_getu32(argv);	/* XID */
1524	svc_getnl(argv);	/* CALLDIR */
1525
1526	/* Parse and execute the bc call */
1527	proc_error = svc_process_common(rqstp, argv, resv);
1528
1529	atomic_dec(&req->rq_xprt->bc_slot_count);
1530	if (!proc_error) {
1531		/* Processing error: drop the request */
 
1532		xprt_free_bc_request(req);
1533		error = -EINVAL;
1534		goto out;
1535	}
1536	/* Finally, send the reply synchronously */
1537	memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
1538	task = rpc_run_bc_task(req);
1539	if (IS_ERR(task)) {
1540		error = PTR_ERR(task);
1541		goto out;
1542	}
1543
1544	WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
1545	error = task->tk_status;
1546	rpc_put_task(task);
1547
1548out:
1549	dprintk("svc: %s(), error=%d\n", __func__, error);
1550	return error;
1551}
1552EXPORT_SYMBOL_GPL(bc_svc_process);
1553#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1554
1555/**
1556 * svc_max_payload - Return transport-specific limit on the RPC payload
1557 * @rqstp: RPC transaction context
1558 *
1559 * Returns the maximum number of payload bytes the current transport
1560 * allows.
1561 */
1562u32 svc_max_payload(const struct svc_rqst *rqstp)
1563{
1564	u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1565
1566	if (rqstp->rq_server->sv_max_payload < max)
1567		max = rqstp->rq_server->sv_max_payload;
1568	return max;
1569}
1570EXPORT_SYMBOL_GPL(svc_max_payload);
1571
1572/**
1573 * svc_proc_name - Return RPC procedure name in string form
1574 * @rqstp: svc_rqst to operate on
1575 *
1576 * Return value:
1577 *   Pointer to a NUL-terminated string
1578 */
1579const char *svc_proc_name(const struct svc_rqst *rqstp)
1580{
1581	if (rqstp && rqstp->rq_procinfo)
1582		return rqstp->rq_procinfo->pc_name;
1583	return "unknown";
1584}
1585
1586
1587/**
1588 * svc_encode_result_payload - mark a range of bytes as a result payload
1589 * @rqstp: svc_rqst to operate on
1590 * @offset: payload's byte offset in rqstp->rq_res
1591 * @length: size of payload, in bytes
1592 *
1593 * Returns zero on success, or a negative errno if a permanent
1594 * error occurred.
1595 */
1596int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset,
1597			      unsigned int length)
1598{
1599	return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset,
1600							   length);
1601}
1602EXPORT_SYMBOL_GPL(svc_encode_result_payload);
1603
1604/**
1605 * svc_fill_write_vector - Construct data argument for VFS write call
1606 * @rqstp: svc_rqst to operate on
1607 * @payload: xdr_buf containing only the write data payload
1608 *
1609 * Fills in rqstp::rq_vec, and returns the number of elements.
1610 */
1611unsigned int svc_fill_write_vector(struct svc_rqst *rqstp,
1612				   struct xdr_buf *payload)
1613{
1614	struct page **pages = payload->pages;
1615	struct kvec *first = payload->head;
1616	struct kvec *vec = rqstp->rq_vec;
1617	size_t total = payload->len;
1618	unsigned int i;
1619
1620	/* Some types of transport can present the write payload
1621	 * entirely in rq_arg.pages. In this case, @first is empty.
1622	 */
1623	i = 0;
1624	if (first->iov_len) {
1625		vec[i].iov_base = first->iov_base;
1626		vec[i].iov_len = min_t(size_t, total, first->iov_len);
1627		total -= vec[i].iov_len;
1628		++i;
1629	}
1630
1631	while (total) {
1632		vec[i].iov_base = page_address(*pages);
1633		vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
1634		total -= vec[i].iov_len;
1635		++i;
1636		++pages;
1637	}
1638
1639	WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
1640	return i;
1641}
1642EXPORT_SYMBOL_GPL(svc_fill_write_vector);
1643
1644/**
1645 * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
1646 * @rqstp: svc_rqst to operate on
1647 * @first: buffer containing first section of pathname
1648 * @p: buffer containing remaining section of pathname
1649 * @total: total length of the pathname argument
1650 *
1651 * The VFS symlink API demands a NUL-terminated pathname in mapped memory.
1652 * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free
1653 * the returned string.
1654 */
1655char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
1656				void *p, size_t total)
1657{
1658	size_t len, remaining;
1659	char *result, *dst;
1660
1661	result = kmalloc(total + 1, GFP_KERNEL);
1662	if (!result)
1663		return ERR_PTR(-ESERVERFAULT);
1664
1665	dst = result;
1666	remaining = total;
1667
1668	len = min_t(size_t, total, first->iov_len);
1669	if (len) {
1670		memcpy(dst, first->iov_base, len);
1671		dst += len;
1672		remaining -= len;
1673	}
1674
1675	if (remaining) {
1676		len = min_t(size_t, remaining, PAGE_SIZE);
1677		memcpy(dst, p, len);
1678		dst += len;
1679	}
1680
1681	*dst = '\0';
1682
1683	/* Sanity check: Linux doesn't allow the pathname argument to
1684	 * contain a NUL byte.
1685	 */
1686	if (strlen(result) != total) {
1687		kfree(result);
1688		return ERR_PTR(-EINVAL);
1689	}
1690	return result;
1691}
1692EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);
v3.5.6
 
   1/*
   2 * linux/net/sunrpc/svc.c
   3 *
   4 * High-level RPC service routines
   5 *
   6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7 *
   8 * Multiple threads pools and NUMAisation
   9 * Copyright (c) 2006 Silicon Graphics, Inc.
  10 * by Greg Banks <gnb@melbourne.sgi.com>
  11 */
  12
  13#include <linux/linkage.h>
  14#include <linux/sched.h>
  15#include <linux/errno.h>
  16#include <linux/net.h>
  17#include <linux/in.h>
  18#include <linux/mm.h>
  19#include <linux/interrupt.h>
  20#include <linux/module.h>
  21#include <linux/kthread.h>
  22#include <linux/slab.h>
  23#include <linux/nsproxy.h>
  24
  25#include <linux/sunrpc/types.h>
  26#include <linux/sunrpc/xdr.h>
  27#include <linux/sunrpc/stats.h>
  28#include <linux/sunrpc/svcsock.h>
  29#include <linux/sunrpc/clnt.h>
  30#include <linux/sunrpc/bc_xprt.h>
  31
 
 
 
 
  32#define RPCDBG_FACILITY	RPCDBG_SVCDSP
  33
  34static void svc_unregister(const struct svc_serv *serv, struct net *net);
  35
  36#define svc_serv_is_pooled(serv)    ((serv)->sv_function)
  37
  38/*
  39 * Mode for mapping cpus to pools.
  40 */
  41enum {
  42	SVC_POOL_AUTO = -1,	/* choose one of the others */
  43	SVC_POOL_GLOBAL,	/* no mapping, just a single global pool
  44				 * (legacy & UP mode) */
  45	SVC_POOL_PERCPU,	/* one pool per cpu */
  46	SVC_POOL_PERNODE	/* one pool per numa node */
  47};
  48#define SVC_POOL_DEFAULT	SVC_POOL_GLOBAL
  49
  50/*
  51 * Structure for mapping cpus to pools and vice versa.
  52 * Setup once during sunrpc initialisation.
  53 */
  54static struct svc_pool_map {
 
  55	int count;			/* How many svc_servs use us */
  56	int mode;			/* Note: int not enum to avoid
  57					 * warnings about "enumeration value
  58					 * not handled in switch" */
  59	unsigned int npools;
  60	unsigned int *pool_to;		/* maps pool id to cpu or node */
  61	unsigned int *to_pool;		/* maps cpu or node to pool id */
  62} svc_pool_map = {
  63	.count = 0,
 
  64	.mode = SVC_POOL_DEFAULT
  65};
 
  66static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
  67
  68static int
  69param_set_pool_mode(const char *val, struct kernel_param *kp)
  70{
  71	int *ip = (int *)kp->arg;
  72	struct svc_pool_map *m = &svc_pool_map;
  73	int err;
  74
  75	mutex_lock(&svc_pool_map_mutex);
  76
  77	err = -EBUSY;
  78	if (m->count)
  79		goto out;
  80
  81	err = 0;
  82	if (!strncmp(val, "auto", 4))
  83		*ip = SVC_POOL_AUTO;
  84	else if (!strncmp(val, "global", 6))
  85		*ip = SVC_POOL_GLOBAL;
  86	else if (!strncmp(val, "percpu", 6))
  87		*ip = SVC_POOL_PERCPU;
  88	else if (!strncmp(val, "pernode", 7))
  89		*ip = SVC_POOL_PERNODE;
  90	else
  91		err = -EINVAL;
  92
  93out:
  94	mutex_unlock(&svc_pool_map_mutex);
  95	return err;
  96}
  97
  98static int
  99param_get_pool_mode(char *buf, struct kernel_param *kp)
 100{
 101	int *ip = (int *)kp->arg;
 102
 103	switch (*ip)
 104	{
 105	case SVC_POOL_AUTO:
 106		return strlcpy(buf, "auto", 20);
 107	case SVC_POOL_GLOBAL:
 108		return strlcpy(buf, "global", 20);
 109	case SVC_POOL_PERCPU:
 110		return strlcpy(buf, "percpu", 20);
 111	case SVC_POOL_PERNODE:
 112		return strlcpy(buf, "pernode", 20);
 113	default:
 114		return sprintf(buf, "%d", *ip);
 115	}
 116}
 117
 118module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
 119		 &svc_pool_map.mode, 0644);
 120
 121/*
 122 * Detect best pool mapping mode heuristically,
 123 * according to the machine's topology.
 124 */
 125static int
 126svc_pool_map_choose_mode(void)
 127{
 128	unsigned int node;
 129
 130	if (nr_online_nodes > 1) {
 131		/*
 132		 * Actually have multiple NUMA nodes,
 133		 * so split pools on NUMA node boundaries
 134		 */
 135		return SVC_POOL_PERNODE;
 136	}
 137
 138	node = first_online_node;
 139	if (nr_cpus_node(node) > 2) {
 140		/*
 141		 * Non-trivial SMP, or CONFIG_NUMA on
 142		 * non-NUMA hardware, e.g. with a generic
 143		 * x86_64 kernel on Xeons.  In this case we
 144		 * want to divide the pools on cpu boundaries.
 145		 */
 146		return SVC_POOL_PERCPU;
 147	}
 148
 149	/* default: one global pool */
 150	return SVC_POOL_GLOBAL;
 151}
 152
 153/*
 154 * Allocate the to_pool[] and pool_to[] arrays.
 155 * Returns 0 on success or an errno.
 156 */
 157static int
 158svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
 159{
 160	m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 161	if (!m->to_pool)
 162		goto fail;
 163	m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 164	if (!m->pool_to)
 165		goto fail_free;
 166
 167	return 0;
 168
 169fail_free:
 170	kfree(m->to_pool);
 171	m->to_pool = NULL;
 172fail:
 173	return -ENOMEM;
 174}
 175
 176/*
 177 * Initialise the pool map for SVC_POOL_PERCPU mode.
 178 * Returns number of pools or <0 on error.
 179 */
 180static int
 181svc_pool_map_init_percpu(struct svc_pool_map *m)
 182{
 183	unsigned int maxpools = nr_cpu_ids;
 184	unsigned int pidx = 0;
 185	unsigned int cpu;
 186	int err;
 187
 188	err = svc_pool_map_alloc_arrays(m, maxpools);
 189	if (err)
 190		return err;
 191
 192	for_each_online_cpu(cpu) {
 193		BUG_ON(pidx > maxpools);
 194		m->to_pool[cpu] = pidx;
 195		m->pool_to[pidx] = cpu;
 196		pidx++;
 197	}
 198	/* cpus brought online later all get mapped to pool0, sorry */
 199
 200	return pidx;
 201};
 202
 203
 204/*
 205 * Initialise the pool map for SVC_POOL_PERNODE mode.
 206 * Returns number of pools or <0 on error.
 207 */
 208static int
 209svc_pool_map_init_pernode(struct svc_pool_map *m)
 210{
 211	unsigned int maxpools = nr_node_ids;
 212	unsigned int pidx = 0;
 213	unsigned int node;
 214	int err;
 215
 216	err = svc_pool_map_alloc_arrays(m, maxpools);
 217	if (err)
 218		return err;
 219
 220	for_each_node_with_cpus(node) {
 221		/* some architectures (e.g. SN2) have cpuless nodes */
 222		BUG_ON(pidx > maxpools);
 223		m->to_pool[node] = pidx;
 224		m->pool_to[pidx] = node;
 225		pidx++;
 226	}
 227	/* nodes brought online later all get mapped to pool0, sorry */
 228
 229	return pidx;
 230}
 231
 232
 233/*
 234 * Add a reference to the global map of cpus to pools (and
 235 * vice versa).  Initialise the map if we're the first user.
 236 * Returns the number of pools.
 
 
 237 */
 238static unsigned int
 239svc_pool_map_get(void)
 240{
 241	struct svc_pool_map *m = &svc_pool_map;
 242	int npools = -1;
 243
 244	mutex_lock(&svc_pool_map_mutex);
 245
 246	if (m->count++) {
 247		mutex_unlock(&svc_pool_map_mutex);
 
 248		return m->npools;
 249	}
 250
 251	if (m->mode == SVC_POOL_AUTO)
 252		m->mode = svc_pool_map_choose_mode();
 253
 254	switch (m->mode) {
 255	case SVC_POOL_PERCPU:
 256		npools = svc_pool_map_init_percpu(m);
 257		break;
 258	case SVC_POOL_PERNODE:
 259		npools = svc_pool_map_init_pernode(m);
 260		break;
 261	}
 262
 263	if (npools < 0) {
 264		/* default, or memory allocation failure */
 265		npools = 1;
 266		m->mode = SVC_POOL_GLOBAL;
 267	}
 268	m->npools = npools;
 269
 
 
 
 
 270	mutex_unlock(&svc_pool_map_mutex);
 271	return m->npools;
 272}
 273
 274
 275/*
 276 * Drop a reference to the global map of cpus to pools.
 
 277 * When the last reference is dropped, the map data is
 278 * freed; this allows the sysadmin to change the pool
 279 * mode using the pool_mode module option without
 280 * rebooting or re-loading sunrpc.ko.
 281 */
 282static void
 283svc_pool_map_put(void)
 284{
 285	struct svc_pool_map *m = &svc_pool_map;
 286
 
 
 287	mutex_lock(&svc_pool_map_mutex);
 288
 289	if (!--m->count) {
 290		kfree(m->to_pool);
 291		m->to_pool = NULL;
 292		kfree(m->pool_to);
 293		m->pool_to = NULL;
 294		m->npools = 0;
 295	}
 296
 297	mutex_unlock(&svc_pool_map_mutex);
 298}
 299
 300
 301static int svc_pool_map_get_node(unsigned int pidx)
 302{
 303	const struct svc_pool_map *m = &svc_pool_map;
 304
 305	if (m->count) {
 306		if (m->mode == SVC_POOL_PERCPU)
 307			return cpu_to_node(m->pool_to[pidx]);
 308		if (m->mode == SVC_POOL_PERNODE)
 309			return m->pool_to[pidx];
 310	}
 311	return NUMA_NO_NODE;
 312}
 313/*
 314 * Set the given thread's cpus_allowed mask so that it
 315 * will only run on cpus in the given pool.
 316 */
 317static inline void
 318svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
 319{
 320	struct svc_pool_map *m = &svc_pool_map;
 321	unsigned int node = m->pool_to[pidx];
 322
 323	/*
 324	 * The caller checks for sv_nrpools > 1, which
 325	 * implies that we've been initialized.
 326	 */
 327	BUG_ON(m->count == 0);
 
 
 328
 329	switch (m->mode) {
 330	case SVC_POOL_PERCPU:
 331	{
 332		set_cpus_allowed_ptr(task, cpumask_of(node));
 333		break;
 334	}
 335	case SVC_POOL_PERNODE:
 336	{
 337		set_cpus_allowed_ptr(task, cpumask_of_node(node));
 338		break;
 339	}
 340	}
 341}
 342
 343/*
 344 * Use the mapping mode to choose a pool for a given CPU.
 345 * Used when enqueueing an incoming RPC.  Always returns
 346 * a non-NULL pool pointer.
 
 
 
 
 
 
 347 */
 348struct svc_pool *
 349svc_pool_for_cpu(struct svc_serv *serv, int cpu)
 350{
 351	struct svc_pool_map *m = &svc_pool_map;
 
 352	unsigned int pidx = 0;
 353
 354	/*
 355	 * An uninitialised map happens in a pure client when
 356	 * lockd is brought up, so silently treat it the
 357	 * same as SVC_POOL_GLOBAL.
 358	 */
 359	if (svc_serv_is_pooled(serv)) {
 360		switch (m->mode) {
 361		case SVC_POOL_PERCPU:
 362			pidx = m->to_pool[cpu];
 363			break;
 364		case SVC_POOL_PERNODE:
 365			pidx = m->to_pool[cpu_to_node(cpu)];
 366			break;
 367		}
 368	}
 
 369	return &serv->sv_pools[pidx % serv->sv_nrpools];
 370}
 371
 372int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
 373{
 374	int err;
 375
 376	err = rpcb_create_local(net);
 377	if (err)
 378		return err;
 379
 380	/* Remove any stale portmap registrations */
 381	svc_unregister(serv, net);
 382	return 0;
 383}
 384EXPORT_SYMBOL_GPL(svc_rpcb_setup);
 385
 386void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
 387{
 388	svc_unregister(serv, net);
 389	rpcb_put_local(net);
 390}
 391EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
 392
 393static int svc_uses_rpcbind(struct svc_serv *serv)
 394{
 395	struct svc_program	*progp;
 396	unsigned int		i;
 397
 398	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 399		for (i = 0; i < progp->pg_nvers; i++) {
 400			if (progp->pg_vers[i] == NULL)
 401				continue;
 402			if (progp->pg_vers[i]->vs_hidden == 0)
 403				return 1;
 404		}
 405	}
 406
 407	return 0;
 408}
 409
 410int svc_bind(struct svc_serv *serv, struct net *net)
 411{
 412	if (!svc_uses_rpcbind(serv))
 413		return 0;
 414	return svc_rpcb_setup(serv, net);
 415}
 416EXPORT_SYMBOL_GPL(svc_bind);
 417
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 418/*
 419 * Create an RPC service
 420 */
 421static struct svc_serv *
 422__svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 423	     void (*shutdown)(struct svc_serv *serv, struct net *net))
 424{
 425	struct svc_serv	*serv;
 426	unsigned int vers;
 427	unsigned int xdrsize;
 428	unsigned int i;
 429
 430	if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
 431		return NULL;
 432	serv->sv_name      = prog->pg_name;
 433	serv->sv_program   = prog;
 434	serv->sv_nrthreads = 1;
 435	serv->sv_stats     = prog->pg_stats;
 436	if (bufsize > RPCSVC_MAXPAYLOAD)
 437		bufsize = RPCSVC_MAXPAYLOAD;
 438	serv->sv_max_payload = bufsize? bufsize : 4096;
 439	serv->sv_max_mesg  = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
 440	serv->sv_shutdown  = shutdown;
 441	xdrsize = 0;
 442	while (prog) {
 443		prog->pg_lovers = prog->pg_nvers-1;
 444		for (vers=0; vers<prog->pg_nvers ; vers++)
 445			if (prog->pg_vers[vers]) {
 446				prog->pg_hivers = vers;
 447				if (prog->pg_lovers > vers)
 448					prog->pg_lovers = vers;
 449				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
 450					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
 451			}
 452		prog = prog->pg_next;
 453	}
 454	serv->sv_xdrsize   = xdrsize;
 455	INIT_LIST_HEAD(&serv->sv_tempsocks);
 456	INIT_LIST_HEAD(&serv->sv_permsocks);
 457	init_timer(&serv->sv_temptimer);
 458	spin_lock_init(&serv->sv_lock);
 459
 
 
 460	serv->sv_nrpools = npools;
 461	serv->sv_pools =
 462		kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
 463			GFP_KERNEL);
 464	if (!serv->sv_pools) {
 465		kfree(serv);
 466		return NULL;
 467	}
 468
 469	for (i = 0; i < serv->sv_nrpools; i++) {
 470		struct svc_pool *pool = &serv->sv_pools[i];
 471
 472		dprintk("svc: initialising pool %u for %s\n",
 473				i, serv->sv_name);
 474
 475		pool->sp_id = i;
 476		INIT_LIST_HEAD(&pool->sp_threads);
 477		INIT_LIST_HEAD(&pool->sp_sockets);
 478		INIT_LIST_HEAD(&pool->sp_all_threads);
 479		spin_lock_init(&pool->sp_lock);
 480	}
 481
 482	if (svc_uses_rpcbind(serv) && (!serv->sv_shutdown))
 483		serv->sv_shutdown = svc_rpcb_cleanup;
 484
 485	return serv;
 486}
 487
 488struct svc_serv *
 489svc_create(struct svc_program *prog, unsigned int bufsize,
 490	   void (*shutdown)(struct svc_serv *serv, struct net *net))
 
 
 
 
 
 
 
 491{
 492	return __svc_create(prog, bufsize, /*npools*/1, shutdown);
 493}
 494EXPORT_SYMBOL_GPL(svc_create);
 495
 496struct svc_serv *
 497svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
 498		  void (*shutdown)(struct svc_serv *serv, struct net *net),
 499		  svc_thread_fn func, struct module *mod)
 
 
 
 
 
 
 
 500{
 501	struct svc_serv *serv;
 502	unsigned int npools = svc_pool_map_get();
 503
 504	serv = __svc_create(prog, bufsize, npools, shutdown);
 505
 506	if (serv != NULL) {
 507		serv->sv_function = func;
 508		serv->sv_module = mod;
 509	}
 510
 511	return serv;
 
 
 
 512}
 513EXPORT_SYMBOL_GPL(svc_create_pooled);
 514
 515void svc_shutdown_net(struct svc_serv *serv, struct net *net)
 516{
 517	/*
 518	 * The set of xprts (contained in the sv_tempsocks and
 519	 * sv_permsocks lists) is now constant, since it is modified
 520	 * only by accepting new sockets (done by service threads in
 521	 * svc_recv) or aging old ones (done by sv_temptimer), or
 522	 * configuration changes (excluded by whatever locking the
 523	 * caller is using--nfsd_mutex in the case of nfsd).  So it's
 524	 * safe to traverse those lists and shut everything down:
 525	 */
 526	svc_close_net(serv, net);
 527
 528	if (serv->sv_shutdown)
 529		serv->sv_shutdown(serv, net);
 530}
 531EXPORT_SYMBOL_GPL(svc_shutdown_net);
 532
 533/*
 534 * Destroy an RPC service. Should be called with appropriate locking to
 535 * protect the sv_nrthreads, sv_permsocks and sv_tempsocks.
 536 */
 537void
 538svc_destroy(struct svc_serv *serv)
 539{
 540	dprintk("svc: svc_destroy(%s, %d)\n",
 541				serv->sv_program->pg_name,
 542				serv->sv_nrthreads);
 543
 544	if (serv->sv_nrthreads) {
 545		if (--(serv->sv_nrthreads) != 0) {
 546			svc_sock_update_bufs(serv);
 547			return;
 548		}
 549	} else
 550		printk("svc_destroy: no threads for serv=%p!\n", serv);
 551
 552	del_timer_sync(&serv->sv_temptimer);
 
 553
 554	/*
 555	 * The last user is gone and thus all sockets have to be destroyed to
 556	 * the point. Check this.
 557	 */
 558	BUG_ON(!list_empty(&serv->sv_permsocks));
 559	BUG_ON(!list_empty(&serv->sv_tempsocks));
 560
 561	cache_clean_deferred(serv);
 562
 563	if (svc_serv_is_pooled(serv))
 564		svc_pool_map_put();
 565
 566	kfree(serv->sv_pools);
 567	kfree(serv);
 568}
 569EXPORT_SYMBOL_GPL(svc_destroy);
 570
 571/*
 572 * Allocate an RPC server's buffer space.
 573 * We allocate pages and place them in rq_argpages.
 574 */
 575static int
 576svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
 577{
 578	unsigned int pages, arghi;
 579
 580	/* bc_xprt uses fore channel allocated buffers */
 581	if (svc_is_backchannel(rqstp))
 582		return 1;
 583
 584	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 585				       * We assume one is at most one page
 586				       */
 587	arghi = 0;
 588	BUG_ON(pages > RPCSVC_MAXPAGES);
 
 
 589	while (pages) {
 590		struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
 591		if (!p)
 592			break;
 593		rqstp->rq_pages[arghi++] = p;
 594		pages--;
 595	}
 596	return pages == 0;
 597}
 598
 599/*
 600 * Release an RPC server buffer
 601 */
 602static void
 603svc_release_buffer(struct svc_rqst *rqstp)
 604{
 605	unsigned int i;
 606
 607	for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
 608		if (rqstp->rq_pages[i])
 609			put_page(rqstp->rq_pages[i]);
 610}
 611
 612struct svc_rqst *
 613svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
 614{
 615	struct svc_rqst	*rqstp;
 616
 617	rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
 618	if (!rqstp)
 619		goto out_enomem;
 620
 621	init_waitqueue_head(&rqstp->rq_wait);
 622
 623	serv->sv_nrthreads++;
 624	spin_lock_bh(&pool->sp_lock);
 625	pool->sp_nrthreads++;
 626	list_add(&rqstp->rq_all, &pool->sp_all_threads);
 627	spin_unlock_bh(&pool->sp_lock);
 628	rqstp->rq_server = serv;
 629	rqstp->rq_pool = pool;
 630
 
 
 
 
 631	rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 632	if (!rqstp->rq_argp)
 633		goto out_thread;
 634
 635	rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 636	if (!rqstp->rq_resp)
 637		goto out_thread;
 638
 639	if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
 640		goto out_thread;
 641
 642	return rqstp;
 643out_thread:
 644	svc_exit_thread(rqstp);
 645out_enomem:
 646	return ERR_PTR(-ENOMEM);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 647}
 648EXPORT_SYMBOL_GPL(svc_prepare_thread);
 649
 650/*
 651 * Choose a pool in which to create a new thread, for svc_set_num_threads
 652 */
 653static inline struct svc_pool *
 654choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 655{
 656	if (pool != NULL)
 657		return pool;
 658
 659	return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
 660}
 661
 662/*
 663 * Choose a thread to kill, for svc_set_num_threads
 664 */
 665static inline struct task_struct *
 666choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 667{
 668	unsigned int i;
 669	struct task_struct *task = NULL;
 670
 671	if (pool != NULL) {
 672		spin_lock_bh(&pool->sp_lock);
 673	} else {
 674		/* choose a pool in round-robin fashion */
 675		for (i = 0; i < serv->sv_nrpools; i++) {
 676			pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
 677			spin_lock_bh(&pool->sp_lock);
 678			if (!list_empty(&pool->sp_all_threads))
 679				goto found_pool;
 680			spin_unlock_bh(&pool->sp_lock);
 681		}
 682		return NULL;
 683	}
 684
 685found_pool:
 686	if (!list_empty(&pool->sp_all_threads)) {
 687		struct svc_rqst *rqstp;
 688
 689		/*
 690		 * Remove from the pool->sp_all_threads list
 691		 * so we don't try to kill it again.
 692		 */
 693		rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
 694		list_del_init(&rqstp->rq_all);
 
 695		task = rqstp->rq_task;
 696	}
 697	spin_unlock_bh(&pool->sp_lock);
 698
 699	return task;
 700}
 701
 702/*
 703 * Create or destroy enough new threads to make the number
 704 * of threads the given number.  If `pool' is non-NULL, applies
 705 * only to threads in that pool, otherwise round-robins between
 706 * all pools.  Caller must ensure that mutual exclusion between this and
 707 * server startup or shutdown.
 708 *
 709 * Destroying threads relies on the service threads filling in
 710 * rqstp->rq_task, which only the nfs ones do.  Assumes the serv
 711 * has been created using svc_create_pooled().
 712 *
 713 * Based on code that used to be in nfsd_svc() but tweaked
 714 * to be pool-aware.
 715 */
 716int
 717svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 718{
 719	struct svc_rqst	*rqstp;
 720	struct task_struct *task;
 721	struct svc_pool *chosen_pool;
 722	int error = 0;
 723	unsigned int state = serv->sv_nrthreads-1;
 724	int node;
 725
 726	if (pool == NULL) {
 727		/* The -1 assumes caller has done a svc_get() */
 728		nrservs -= (serv->sv_nrthreads-1);
 729	} else {
 730		spin_lock_bh(&pool->sp_lock);
 731		nrservs -= pool->sp_nrthreads;
 732		spin_unlock_bh(&pool->sp_lock);
 733	}
 734
 735	/* create new threads */
 736	while (nrservs > 0) {
 737		nrservs--;
 738		chosen_pool = choose_pool(serv, pool, &state);
 739
 740		node = svc_pool_map_get_node(chosen_pool->sp_id);
 741		rqstp = svc_prepare_thread(serv, chosen_pool, node);
 742		if (IS_ERR(rqstp)) {
 743			error = PTR_ERR(rqstp);
 744			break;
 745		}
 746
 747		__module_get(serv->sv_module);
 748		task = kthread_create_on_node(serv->sv_function, rqstp,
 749					      node, serv->sv_name);
 750		if (IS_ERR(task)) {
 751			error = PTR_ERR(task);
 752			module_put(serv->sv_module);
 753			svc_exit_thread(rqstp);
 754			break;
 755		}
 756
 757		rqstp->rq_task = task;
 758		if (serv->sv_nrpools > 1)
 759			svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
 760
 761		svc_sock_update_bufs(serv);
 762		wake_up_process(task);
 763	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 764	/* destroy old threads */
 765	while (nrservs < 0 &&
 766	       (task = choose_victim(serv, pool, &state)) != NULL) {
 767		send_sig(SIGINT, task, 1);
 
 
 768		nrservs++;
 
 
 
 
 
 
 
 
 
 
 
 
 
 769	}
 770
 771	return error;
 
 
 
 
 772}
 773EXPORT_SYMBOL_GPL(svc_set_num_threads);
 774
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 775/*
 776 * Called from a server thread as it's exiting. Caller must hold the BKL or
 777 * the "service mutex", whichever is appropriate for the service.
 778 */
 779void
 780svc_exit_thread(struct svc_rqst *rqstp)
 781{
 782	struct svc_serv	*serv = rqstp->rq_server;
 783	struct svc_pool	*pool = rqstp->rq_pool;
 784
 785	svc_release_buffer(rqstp);
 
 
 786	kfree(rqstp->rq_resp);
 787	kfree(rqstp->rq_argp);
 788	kfree(rqstp->rq_auth_data);
 
 
 
 
 
 
 
 
 
 789
 790	spin_lock_bh(&pool->sp_lock);
 791	pool->sp_nrthreads--;
 792	list_del(&rqstp->rq_all);
 
 793	spin_unlock_bh(&pool->sp_lock);
 794
 795	kfree(rqstp);
 
 
 
 
 
 796
 797	/* Release the server */
 798	if (serv)
 799		svc_destroy(serv);
 800}
 801EXPORT_SYMBOL_GPL(svc_exit_thread);
 802
 803/*
 804 * Register an "inet" protocol family netid with the local
 805 * rpcbind daemon via an rpcbind v4 SET request.
 806 *
 807 * No netconfig infrastructure is available in the kernel, so
 808 * we map IP_ protocol numbers to netids by hand.
 809 *
 810 * Returns zero on success; a negative errno value is returned
 811 * if any error occurs.
 812 */
 813static int __svc_rpcb_register4(struct net *net, const u32 program,
 814				const u32 version,
 815				const unsigned short protocol,
 816				const unsigned short port)
 817{
 818	const struct sockaddr_in sin = {
 819		.sin_family		= AF_INET,
 820		.sin_addr.s_addr	= htonl(INADDR_ANY),
 821		.sin_port		= htons(port),
 822	};
 823	const char *netid;
 824	int error;
 825
 826	switch (protocol) {
 827	case IPPROTO_UDP:
 828		netid = RPCBIND_NETID_UDP;
 829		break;
 830	case IPPROTO_TCP:
 831		netid = RPCBIND_NETID_TCP;
 832		break;
 833	default:
 834		return -ENOPROTOOPT;
 835	}
 836
 837	error = rpcb_v4_register(net, program, version,
 838					(const struct sockaddr *)&sin, netid);
 839
 840	/*
 841	 * User space didn't support rpcbind v4, so retry this
 842	 * registration request with the legacy rpcbind v2 protocol.
 843	 */
 844	if (error == -EPROTONOSUPPORT)
 845		error = rpcb_register(net, program, version, protocol, port);
 846
 847	return error;
 848}
 849
 850#if IS_ENABLED(CONFIG_IPV6)
 851/*
 852 * Register an "inet6" protocol family netid with the local
 853 * rpcbind daemon via an rpcbind v4 SET request.
 854 *
 855 * No netconfig infrastructure is available in the kernel, so
 856 * we map IP_ protocol numbers to netids by hand.
 857 *
 858 * Returns zero on success; a negative errno value is returned
 859 * if any error occurs.
 860 */
 861static int __svc_rpcb_register6(struct net *net, const u32 program,
 862				const u32 version,
 863				const unsigned short protocol,
 864				const unsigned short port)
 865{
 866	const struct sockaddr_in6 sin6 = {
 867		.sin6_family		= AF_INET6,
 868		.sin6_addr		= IN6ADDR_ANY_INIT,
 869		.sin6_port		= htons(port),
 870	};
 871	const char *netid;
 872	int error;
 873
 874	switch (protocol) {
 875	case IPPROTO_UDP:
 876		netid = RPCBIND_NETID_UDP6;
 877		break;
 878	case IPPROTO_TCP:
 879		netid = RPCBIND_NETID_TCP6;
 880		break;
 881	default:
 882		return -ENOPROTOOPT;
 883	}
 884
 885	error = rpcb_v4_register(net, program, version,
 886					(const struct sockaddr *)&sin6, netid);
 887
 888	/*
 889	 * User space didn't support rpcbind version 4, so we won't
 890	 * use a PF_INET6 listener.
 891	 */
 892	if (error == -EPROTONOSUPPORT)
 893		error = -EAFNOSUPPORT;
 894
 895	return error;
 896}
 897#endif	/* IS_ENABLED(CONFIG_IPV6) */
 898
 899/*
 900 * Register a kernel RPC service via rpcbind version 4.
 901 *
 902 * Returns zero on success; a negative errno value is returned
 903 * if any error occurs.
 904 */
 905static int __svc_register(struct net *net, const char *progname,
 906			  const u32 program, const u32 version,
 907			  const int family,
 908			  const unsigned short protocol,
 909			  const unsigned short port)
 910{
 911	int error = -EAFNOSUPPORT;
 912
 913	switch (family) {
 914	case PF_INET:
 915		error = __svc_rpcb_register4(net, program, version,
 916						protocol, port);
 917		break;
 918#if IS_ENABLED(CONFIG_IPV6)
 919	case PF_INET6:
 920		error = __svc_rpcb_register6(net, program, version,
 921						protocol, port);
 922#endif
 923	}
 924
 925	if (error < 0)
 926		printk(KERN_WARNING "svc: failed to register %sv%u RPC "
 927			"service (errno %d).\n", progname, version, -error);
 928	return error;
 929}
 930
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 931/**
 932 * svc_register - register an RPC service with the local portmapper
 933 * @serv: svc_serv struct for the service to register
 934 * @net: net namespace for the service to register
 935 * @family: protocol family of service's listener socket
 936 * @proto: transport protocol number to advertise
 937 * @port: port to advertise
 938 *
 939 * Service is registered for any address in the passed-in protocol family
 940 */
 941int svc_register(const struct svc_serv *serv, struct net *net,
 942		 const int family, const unsigned short proto,
 943		 const unsigned short port)
 944{
 945	struct svc_program	*progp;
 946	unsigned int		i;
 947	int			error = 0;
 948
 949	BUG_ON(proto == 0 && port == 0);
 
 
 950
 951	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 952		for (i = 0; i < progp->pg_nvers; i++) {
 953			if (progp->pg_vers[i] == NULL)
 954				continue;
 955
 956			dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
 957					progp->pg_name,
 958					i,
 959					proto == IPPROTO_UDP?  "udp" : "tcp",
 960					port,
 961					family,
 962					progp->pg_vers[i]->vs_hidden?
 963						" (but not telling portmap)" : "");
 964
 965			if (progp->pg_vers[i]->vs_hidden)
 966				continue;
 967
 968			error = __svc_register(net, progp->pg_name, progp->pg_prog,
 969						i, family, proto, port);
 970			if (error < 0)
 971				break;
 
 972		}
 973	}
 974
 975	return error;
 976}
 977
 978/*
 979 * If user space is running rpcbind, it should take the v4 UNSET
 980 * and clear everything for this [program, version].  If user space
 981 * is running portmap, it will reject the v4 UNSET, but won't have
 982 * any "inet6" entries anyway.  So a PMAP_UNSET should be sufficient
 983 * in this case to clear all existing entries for [program, version].
 984 */
 985static void __svc_unregister(struct net *net, const u32 program, const u32 version,
 986			     const char *progname)
 987{
 988	int error;
 989
 990	error = rpcb_v4_register(net, program, version, NULL, "");
 991
 992	/*
 993	 * User space didn't support rpcbind v4, so retry this
 994	 * request with the legacy rpcbind v2 protocol.
 995	 */
 996	if (error == -EPROTONOSUPPORT)
 997		error = rpcb_register(net, program, version, 0, 0);
 998
 999	dprintk("svc: %s(%sv%u), error %d\n",
1000			__func__, progname, version, error);
1001}
1002
1003/*
1004 * All netids, bind addresses and ports registered for [program, version]
1005 * are removed from the local rpcbind database (if the service is not
1006 * hidden) to make way for a new instance of the service.
1007 *
1008 * The result of unregistration is reported via dprintk for those who want
1009 * verification of the result, but is otherwise not important.
1010 */
1011static void svc_unregister(const struct svc_serv *serv, struct net *net)
1012{
1013	struct svc_program *progp;
1014	unsigned long flags;
1015	unsigned int i;
1016
1017	clear_thread_flag(TIF_SIGPENDING);
1018
1019	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1020		for (i = 0; i < progp->pg_nvers; i++) {
1021			if (progp->pg_vers[i] == NULL)
1022				continue;
1023			if (progp->pg_vers[i]->vs_hidden)
1024				continue;
1025
1026			dprintk("svc: attempting to unregister %sv%u\n",
1027				progp->pg_name, i);
1028			__svc_unregister(net, progp->pg_prog, i, progp->pg_name);
1029		}
1030	}
1031
1032	spin_lock_irqsave(&current->sighand->siglock, flags);
1033	recalc_sigpending();
1034	spin_unlock_irqrestore(&current->sighand->siglock, flags);
1035}
1036
1037/*
1038 * Printk the given error with the address of the client that caused it.
1039 */
 
1040static __printf(2, 3)
1041void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
1042{
1043	struct va_format vaf;
1044	va_list args;
1045	char 	buf[RPC_MAX_ADDRBUFLEN];
1046
1047	va_start(args, fmt);
1048
1049	vaf.fmt = fmt;
1050	vaf.va = &args;
1051
1052	net_warn_ratelimited("svc: %s: %pV",
1053			     svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
1054
1055	va_end(args);
1056}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1057
1058/*
1059 * Common routine for processing the RPC request.
1060 */
1061static int
1062svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
1063{
1064	struct svc_program	*progp;
1065	struct svc_version	*versp = NULL;	/* compiler food */
1066	struct svc_procedure	*procp = NULL;
1067	struct svc_serv		*serv = rqstp->rq_server;
1068	kxdrproc_t		xdr;
1069	__be32			*statp;
1070	u32			prog, vers, proc;
1071	__be32			auth_stat, rpc_stat;
1072	int			auth_res;
1073	__be32			*reply_statp;
1074
1075	rpc_stat = rpc_success;
1076
1077	if (argv->iov_len < 6*4)
1078		goto err_short_len;
1079
1080	/* Will be turned off only in gss privacy case: */
1081	rqstp->rq_splice_ok = 1;
1082	/* Will be turned off only when NFSv4 Sessions are used */
1083	rqstp->rq_usedeferral = 1;
1084	rqstp->rq_dropme = false;
1085
1086	/* Setup reply header */
1087	rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
1088
1089	svc_putu32(resv, rqstp->rq_xid);
1090
1091	vers = svc_getnl(argv);
1092
1093	/* First words of reply: */
1094	svc_putnl(resv, 1);		/* REPLY */
1095
1096	if (vers != 2)		/* RPC version number */
1097		goto err_bad_rpc;
1098
1099	/* Save position in case we later decide to reject: */
1100	reply_statp = resv->iov_base + resv->iov_len;
1101
1102	svc_putnl(resv, 0);		/* ACCEPT */
1103
1104	rqstp->rq_prog = prog = svc_getnl(argv);	/* program number */
1105	rqstp->rq_vers = vers = svc_getnl(argv);	/* version number */
1106	rqstp->rq_proc = proc = svc_getnl(argv);	/* procedure number */
1107
1108	progp = serv->sv_program;
1109
1110	for (progp = serv->sv_program; progp; progp = progp->pg_next)
1111		if (prog == progp->pg_prog)
1112			break;
1113
1114	/*
1115	 * Decode auth data, and add verifier to reply buffer.
1116	 * We do this before anything else in order to get a decent
1117	 * auth verifier.
1118	 */
1119	auth_res = svc_authenticate(rqstp, &auth_stat);
1120	/* Also give the program a chance to reject this call: */
1121	if (auth_res == SVC_OK && progp) {
1122		auth_stat = rpc_autherr_badcred;
1123		auth_res = progp->pg_authenticate(rqstp);
1124	}
1125	switch (auth_res) {
1126	case SVC_OK:
1127		break;
1128	case SVC_GARBAGE:
1129		goto err_garbage;
1130	case SVC_SYSERR:
1131		rpc_stat = rpc_system_err;
1132		goto err_bad;
1133	case SVC_DENIED:
1134		goto err_bad_auth;
1135	case SVC_CLOSE:
1136		if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1137			svc_close_xprt(rqstp->rq_xprt);
1138	case SVC_DROP:
1139		goto dropit;
1140	case SVC_COMPLETE:
1141		goto sendit;
1142	}
1143
1144	if (progp == NULL)
1145		goto err_bad_prog;
1146
1147	if (vers >= progp->pg_nvers ||
1148	  !(versp = progp->pg_vers[vers]))
 
 
 
 
 
1149		goto err_bad_vers;
 
 
 
1150
1151	procp = versp->vs_proc + proc;
1152	if (proc >= versp->vs_nproc || !procp->pc_func)
 
1153		goto err_bad_proc;
1154	rqstp->rq_procinfo = procp;
1155
1156	/* Syntactic check complete */
1157	serv->sv_stats->rpccnt++;
 
1158
1159	/* Build the reply header. */
1160	statp = resv->iov_base +resv->iov_len;
1161	svc_putnl(resv, RPC_SUCCESS);
1162
1163	/* Bump per-procedure stats counter */
1164	procp->pc_count++;
1165
1166	/* Initialize storage for argp and resp */
1167	memset(rqstp->rq_argp, 0, procp->pc_argsize);
1168	memset(rqstp->rq_resp, 0, procp->pc_ressize);
1169
1170	/* un-reserve some of the out-queue now that we have a
1171	 * better idea of reply size
1172	 */
1173	if (procp->pc_xdrressize)
1174		svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1175
1176	/* Call the function that processes the request. */
1177	if (!versp->vs_dispatch) {
1178		/* Decode arguments */
1179		xdr = procp->pc_decode;
1180		if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
1181			goto err_garbage;
1182
1183		*statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
1184
1185		/* Encode reply */
1186		if (rqstp->rq_dropme) {
1187			if (procp->pc_release)
1188				procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1189			goto dropit;
1190		}
1191		if (*statp == rpc_success &&
1192		    (xdr = procp->pc_encode) &&
1193		    !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
1194			dprintk("svc: failed to encode reply\n");
1195			/* serv->sv_stats->rpcsystemerr++; */
1196			*statp = rpc_system_err;
1197		}
1198	} else {
1199		dprintk("svc: calling dispatcher\n");
1200		if (!versp->vs_dispatch(rqstp, statp)) {
1201			/* Release reply info */
1202			if (procp->pc_release)
1203				procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1204			goto dropit;
1205		}
1206	}
1207
1208	/* Check RPC status result */
1209	if (*statp != rpc_success)
1210		resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
1211
1212	/* Release reply info */
1213	if (procp->pc_release)
1214		procp->pc_release(rqstp, NULL, rqstp->rq_resp);
1215
1216	if (procp->pc_encode == NULL)
1217		goto dropit;
1218
1219 sendit:
1220	if (svc_authorise(rqstp))
1221		goto dropit;
1222	return 1;		/* Caller can now send it */
1223
1224 dropit:
1225	svc_authorise(rqstp);	/* doesn't hurt to call this twice */
1226	dprintk("svc: svc_process dropit\n");
1227	return 0;
1228
 
 
 
 
 
 
 
 
1229err_short_len:
1230	svc_printk(rqstp, "short len %Zd, dropping request\n",
1231			argv->iov_len);
1232
1233	goto dropit;			/* drop request */
1234
1235err_bad_rpc:
1236	serv->sv_stats->rpcbadfmt++;
1237	svc_putnl(resv, 1);	/* REJECT */
1238	svc_putnl(resv, 0);	/* RPC_MISMATCH */
1239	svc_putnl(resv, 2);	/* Only RPCv2 supported */
1240	svc_putnl(resv, 2);
1241	goto sendit;
1242
1243err_bad_auth:
1244	dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 
1245	serv->sv_stats->rpcbadauth++;
1246	/* Restore write pointer to location of accept status: */
1247	xdr_ressize_check(rqstp, reply_statp);
1248	svc_putnl(resv, 1);	/* REJECT */
1249	svc_putnl(resv, 1);	/* AUTH_ERROR */
1250	svc_putnl(resv, ntohl(auth_stat));	/* status */
1251	goto sendit;
1252
1253err_bad_prog:
1254	dprintk("svc: unknown program %d\n", prog);
1255	serv->sv_stats->rpcbadfmt++;
1256	svc_putnl(resv, RPC_PROG_UNAVAIL);
1257	goto sendit;
1258
1259err_bad_vers:
1260	svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1261		       vers, prog, progp->pg_name);
1262
1263	serv->sv_stats->rpcbadfmt++;
1264	svc_putnl(resv, RPC_PROG_MISMATCH);
1265	svc_putnl(resv, progp->pg_lovers);
1266	svc_putnl(resv, progp->pg_hivers);
1267	goto sendit;
1268
1269err_bad_proc:
1270	svc_printk(rqstp, "unknown procedure (%d)\n", proc);
1271
1272	serv->sv_stats->rpcbadfmt++;
1273	svc_putnl(resv, RPC_PROC_UNAVAIL);
1274	goto sendit;
1275
1276err_garbage:
1277	svc_printk(rqstp, "failed to decode args\n");
1278
1279	rpc_stat = rpc_garbage_args;
1280err_bad:
1281	serv->sv_stats->rpcbadfmt++;
1282	svc_putnl(resv, ntohl(rpc_stat));
1283	goto sendit;
1284}
1285EXPORT_SYMBOL_GPL(svc_process);
1286
1287/*
1288 * Process the RPC request.
1289 */
1290int
1291svc_process(struct svc_rqst *rqstp)
1292{
1293	struct kvec		*argv = &rqstp->rq_arg.head[0];
1294	struct kvec		*resv = &rqstp->rq_res.head[0];
1295	struct svc_serv		*serv = rqstp->rq_server;
1296	u32			dir;
 
 
 
 
 
1297
1298	/*
1299	 * Setup response xdr_buf.
1300	 * Initially it has just one page
1301	 */
1302	rqstp->rq_resused = 1;
1303	resv->iov_base = page_address(rqstp->rq_respages[0]);
1304	resv->iov_len = 0;
1305	rqstp->rq_res.pages = rqstp->rq_respages + 1;
1306	rqstp->rq_res.len = 0;
1307	rqstp->rq_res.page_base = 0;
1308	rqstp->rq_res.page_len = 0;
1309	rqstp->rq_res.buflen = PAGE_SIZE;
1310	rqstp->rq_res.tail[0].iov_base = NULL;
1311	rqstp->rq_res.tail[0].iov_len = 0;
1312
1313	rqstp->rq_xid = svc_getu32(argv);
1314
1315	dir  = svc_getnl(argv);
1316	if (dir != 0) {
1317		/* direction != CALL */
1318		svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
1319		serv->sv_stats->rpcbadfmt++;
1320		svc_drop(rqstp);
1321		return 0;
1322	}
1323
1324	/* Returns 1 for send, 0 for drop */
1325	if (svc_process_common(rqstp, argv, resv))
1326		return svc_send(rqstp);
1327	else {
1328		svc_drop(rqstp);
1329		return 0;
1330	}
1331}
 
1332
1333#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1334/*
1335 * Process a backchannel RPC request that arrived over an existing
1336 * outbound connection
1337 */
1338int
1339bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
1340	       struct svc_rqst *rqstp)
1341{
1342	struct kvec	*argv = &rqstp->rq_arg.head[0];
1343	struct kvec	*resv = &rqstp->rq_res.head[0];
 
 
 
 
 
1344
1345	/* Build the svc_rqst used by the common processing routine */
1346	rqstp->rq_xprt = serv->sv_bc_xprt;
1347	rqstp->rq_xid = req->rq_xid;
1348	rqstp->rq_prot = req->rq_xprt->prot;
1349	rqstp->rq_server = serv;
 
1350
1351	rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1352	memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1353	memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1354	memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1355
 
 
 
 
 
 
 
 
 
 
 
 
 
1356	/* reset result send buffer "put" position */
1357	resv->iov_len = 0;
1358
1359	if (rqstp->rq_prot != IPPROTO_TCP) {
1360		printk(KERN_ERR "No support for Non-TCP transports!\n");
1361		BUG();
1362	}
1363
1364	/*
1365	 * Skip the next two words because they've already been
1366	 * processed in the trasport
1367	 */
1368	svc_getu32(argv);	/* XID */
1369	svc_getnl(argv);	/* CALLDIR */
1370
1371	/* Returns 1 for send, 0 for drop */
1372	if (svc_process_common(rqstp, argv, resv)) {
1373		memcpy(&req->rq_snd_buf, &rqstp->rq_res,
1374						sizeof(req->rq_snd_buf));
1375		return bc_send(req);
1376	} else {
1377		/* drop request */
1378		xprt_free_bc_request(req);
1379		return 0;
 
 
 
 
 
 
 
 
1380	}
 
 
 
 
 
 
 
 
1381}
1382EXPORT_SYMBOL_GPL(bc_svc_process);
1383#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1384
1385/*
1386 * Return (transport-specific) limit on the rpc payload.
 
 
 
 
1387 */
1388u32 svc_max_payload(const struct svc_rqst *rqstp)
1389{
1390	u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1391
1392	if (rqstp->rq_server->sv_max_payload < max)
1393		max = rqstp->rq_server->sv_max_payload;
1394	return max;
1395}
1396EXPORT_SYMBOL_GPL(svc_max_payload);