1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPVS: Locality-Based Least-Connection with Replication scheduler 4 * 5 * Authors: Wensong Zhang <wensong@gnuchina.org> 6 * 7 * Changes: 8 * Julian Anastasov : Added the missing (dest->weight>0) 9 * condition in the ip_vs_dest_set_max. 10 */ 11 12 /* 13 * The lblc/r algorithm is as follows (pseudo code): 14 * 15 * if serverSet[dest_ip] is null then 16 * n, serverSet[dest_ip] <- {weighted least-conn node}; 17 * else 18 * n <- {least-conn (alive) node in serverSet[dest_ip]}; 19 * if (n is null) OR 20 * (n.conns>n.weight AND 21 * there is a node m with m.conns<m.weight/2) then 22 * n <- {weighted least-conn node}; 23 * add n to serverSet[dest_ip]; 24 * if |serverSet[dest_ip]| > 1 AND 25 * now - serverSet[dest_ip].lastMod > T then 26 * m <- {most conn node in serverSet[dest_ip]}; 27 * remove m from serverSet[dest_ip]; 28 * if serverSet[dest_ip] changed then 29 * serverSet[dest_ip].lastMod <- now; 30 * 31 * return n; 32 * 33 */ 34 35 #define KMSG_COMPONENT "IPVS" 36 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 37 38 #include <linux/ip.h> 39 #include <linux/module.h> 40 #include <linux/kernel.h> 41 #include <linux/skbuff.h> 42 #include <linux/jiffies.h> 43 #include <linux/list.h> 44 #include <linux/slab.h> 45 #include <linux/hash.h> 46 47 /* for sysctl */ 48 #include <linux/fs.h> 49 #include <linux/sysctl.h> 50 #include <net/net_namespace.h> 51 52 #include <net/ip_vs.h> 53 54 55 /* 56 * It is for garbage collection of stale IPVS lblcr entries, 57 * when the table is full. 58 */ 59 #define CHECK_EXPIRE_INTERVAL (60*HZ) 60 #define ENTRY_TIMEOUT (6*60*HZ) 61 62 #define DEFAULT_EXPIRATION (24*60*60*HZ) 63 64 /* 65 * It is for full expiration check. 66 * When there is no partial expiration check (garbage collection) 67 * in a half hour, do a full expiration check to collect stale 68 * entries that haven't been touched for a day. 69 */ 70 #define COUNT_FOR_FULL_EXPIRATION 30 71 72 /* 73 * for IPVS lblcr entry hash table 74 */ 75 #ifndef CONFIG_IP_VS_LBLCR_TAB_BITS 76 #define CONFIG_IP_VS_LBLCR_TAB_BITS 10 77 #endif 78 #define IP_VS_LBLCR_TAB_BITS CONFIG_IP_VS_LBLCR_TAB_BITS 79 #define IP_VS_LBLCR_TAB_SIZE (1 << IP_VS_LBLCR_TAB_BITS) 80 #define IP_VS_LBLCR_TAB_MASK (IP_VS_LBLCR_TAB_SIZE - 1) 81 82 83 /* 84 * IPVS destination set structure and operations 85 */ 86 struct ip_vs_dest_set_elem { 87 struct list_head list; /* list link */ 88 struct ip_vs_dest *dest; /* destination server */ 89 struct rcu_head rcu_head; 90 }; 91 92 struct ip_vs_dest_set { 93 atomic_t size; /* set size */ 94 unsigned long lastmod; /* last modified time */ 95 struct list_head list; /* destination list */ 96 }; 97 98 ip_vs_dest_set_insert(struct ip_vs_dest_set * set,struct ip_vs_dest * dest,bool check)99 static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set, 100 struct ip_vs_dest *dest, bool check) 101 { 102 struct ip_vs_dest_set_elem *e; 103 104 if (check) { 105 list_for_each_entry(e, &set->list, list) { 106 if (e->dest == dest) 107 return; 108 } 109 } 110 111 e = kmalloc(sizeof(*e), GFP_ATOMIC); 112 if (e == NULL) 113 return; 114 115 ip_vs_dest_hold(dest); 116 e->dest = dest; 117 118 list_add_rcu(&e->list, &set->list); 119 atomic_inc(&set->size); 120 121 set->lastmod = jiffies; 122 } 123 ip_vs_lblcr_elem_rcu_free(struct rcu_head * head)124 static void ip_vs_lblcr_elem_rcu_free(struct rcu_head *head) 125 { 126 struct ip_vs_dest_set_elem *e; 127 128 e = container_of(head, struct ip_vs_dest_set_elem, rcu_head); 129 ip_vs_dest_put_and_free(e->dest); 130 kfree(e); 131 } 132 133 static void ip_vs_dest_set_erase(struct ip_vs_dest_set * set,struct ip_vs_dest * dest)134 ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) 135 { 136 struct ip_vs_dest_set_elem *e; 137 138 list_for_each_entry(e, &set->list, list) { 139 if (e->dest == dest) { 140 /* HIT */ 141 atomic_dec(&set->size); 142 set->lastmod = jiffies; 143 list_del_rcu(&e->list); 144 call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free); 145 break; 146 } 147 } 148 } 149 ip_vs_dest_set_eraseall(struct ip_vs_dest_set * set)150 static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set) 151 { 152 struct ip_vs_dest_set_elem *e, *ep; 153 154 list_for_each_entry_safe(e, ep, &set->list, list) { 155 list_del_rcu(&e->list); 156 call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free); 157 } 158 } 159 160 /* get weighted least-connection node in the destination set */ ip_vs_dest_set_min(struct ip_vs_dest_set * set)161 static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) 162 { 163 struct ip_vs_dest_set_elem *e; 164 struct ip_vs_dest *dest, *least; 165 int loh, doh; 166 167 /* select the first destination server, whose weight > 0 */ 168 list_for_each_entry_rcu(e, &set->list, list) { 169 least = e->dest; 170 if (least->flags & IP_VS_DEST_F_OVERLOAD) 171 continue; 172 173 if ((atomic_read(&least->weight) > 0) 174 && (least->flags & IP_VS_DEST_F_AVAILABLE)) { 175 loh = ip_vs_dest_conn_overhead(least); 176 goto nextstage; 177 } 178 } 179 return NULL; 180 181 /* find the destination with the weighted least load */ 182 nextstage: 183 list_for_each_entry_continue_rcu(e, &set->list, list) { 184 dest = e->dest; 185 if (dest->flags & IP_VS_DEST_F_OVERLOAD) 186 continue; 187 188 doh = ip_vs_dest_conn_overhead(dest); 189 if (((__s64)loh * atomic_read(&dest->weight) > 190 (__s64)doh * atomic_read(&least->weight)) 191 && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { 192 least = dest; 193 loh = doh; 194 } 195 } 196 197 IP_VS_DBG_BUF(6, "%s(): server %s:%d " 198 "activeconns %d refcnt %d weight %d overhead %d\n", 199 __func__, 200 IP_VS_DBG_ADDR(least->af, &least->addr), 201 ntohs(least->port), 202 atomic_read(&least->activeconns), 203 refcount_read(&least->refcnt), 204 atomic_read(&least->weight), loh); 205 return least; 206 } 207 208 209 /* get weighted most-connection node in the destination set */ ip_vs_dest_set_max(struct ip_vs_dest_set * set)210 static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) 211 { 212 struct ip_vs_dest_set_elem *e; 213 struct ip_vs_dest *dest, *most; 214 int moh, doh; 215 216 if (set == NULL) 217 return NULL; 218 219 /* select the first destination server, whose weight > 0 */ 220 list_for_each_entry(e, &set->list, list) { 221 most = e->dest; 222 if (atomic_read(&most->weight) > 0) { 223 moh = ip_vs_dest_conn_overhead(most); 224 goto nextstage; 225 } 226 } 227 return NULL; 228 229 /* find the destination with the weighted most load */ 230 nextstage: 231 list_for_each_entry_continue(e, &set->list, list) { 232 dest = e->dest; 233 doh = ip_vs_dest_conn_overhead(dest); 234 /* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */ 235 if (((__s64)moh * atomic_read(&dest->weight) < 236 (__s64)doh * atomic_read(&most->weight)) 237 && (atomic_read(&dest->weight) > 0)) { 238 most = dest; 239 moh = doh; 240 } 241 } 242 243 IP_VS_DBG_BUF(6, "%s(): server %s:%d " 244 "activeconns %d refcnt %d weight %d overhead %d\n", 245 __func__, 246 IP_VS_DBG_ADDR(most->af, &most->addr), ntohs(most->port), 247 atomic_read(&most->activeconns), 248 refcount_read(&most->refcnt), 249 atomic_read(&most->weight), moh); 250 return most; 251 } 252 253 254 /* 255 * IPVS lblcr entry represents an association between destination 256 * IP address and its destination server set 257 */ 258 struct ip_vs_lblcr_entry { 259 struct hlist_node list; 260 int af; /* address family */ 261 union nf_inet_addr addr; /* destination IP address */ 262 struct ip_vs_dest_set set; /* destination server set */ 263 unsigned long lastuse; /* last used time */ 264 struct rcu_head rcu_head; 265 }; 266 267 268 /* 269 * IPVS lblcr hash table 270 */ 271 struct ip_vs_lblcr_table { 272 struct rcu_head rcu_head; 273 struct hlist_head bucket[IP_VS_LBLCR_TAB_SIZE]; /* hash bucket */ 274 atomic_t entries; /* number of entries */ 275 int max_size; /* maximum size of entries */ 276 struct timer_list periodic_timer; /* collect stale entries */ 277 struct ip_vs_service *svc; /* pointer back to service */ 278 int rover; /* rover for expire check */ 279 int counter; /* counter for no expire */ 280 bool dead; 281 }; 282 283 284 #ifdef CONFIG_SYSCTL 285 /* 286 * IPVS LBLCR sysctl table 287 */ 288 289 static struct ctl_table vs_vars_table[] = { 290 { 291 .procname = "lblcr_expiration", 292 .data = NULL, 293 .maxlen = sizeof(int), 294 .mode = 0644, 295 .proc_handler = proc_dointvec_jiffies, 296 }, 297 }; 298 #endif 299 ip_vs_lblcr_free(struct ip_vs_lblcr_entry * en)300 static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en) 301 { 302 hlist_del_rcu(&en->list); 303 ip_vs_dest_set_eraseall(&en->set); 304 kfree_rcu(en, rcu_head); 305 } 306 307 308 /* 309 * Returns hash value for IPVS LBLCR entry 310 */ 311 static inline unsigned int ip_vs_lblcr_hashkey(int af,const union nf_inet_addr * addr)312 ip_vs_lblcr_hashkey(int af, const union nf_inet_addr *addr) 313 { 314 __be32 addr_fold = addr->ip; 315 316 #ifdef CONFIG_IP_VS_IPV6 317 if (af == AF_INET6) 318 addr_fold = addr->ip6[0]^addr->ip6[1]^ 319 addr->ip6[2]^addr->ip6[3]; 320 #endif 321 return hash_32(ntohl(addr_fold), IP_VS_LBLCR_TAB_BITS); 322 } 323 324 325 /* 326 * Hash an entry in the ip_vs_lblcr_table. 327 * returns bool success. 328 */ 329 static void ip_vs_lblcr_hash(struct ip_vs_lblcr_table * tbl,struct ip_vs_lblcr_entry * en)330 ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en) 331 { 332 unsigned int hash = ip_vs_lblcr_hashkey(en->af, &en->addr); 333 334 hlist_add_head_rcu(&en->list, &tbl->bucket[hash]); 335 atomic_inc(&tbl->entries); 336 } 337 338 339 /* Get ip_vs_lblcr_entry associated with supplied parameters. */ 340 static inline struct ip_vs_lblcr_entry * ip_vs_lblcr_get(int af,struct ip_vs_lblcr_table * tbl,const union nf_inet_addr * addr)341 ip_vs_lblcr_get(int af, struct ip_vs_lblcr_table *tbl, 342 const union nf_inet_addr *addr) 343 { 344 unsigned int hash = ip_vs_lblcr_hashkey(af, addr); 345 struct ip_vs_lblcr_entry *en; 346 347 hlist_for_each_entry_rcu(en, &tbl->bucket[hash], list) 348 if (ip_vs_addr_equal(af, &en->addr, addr)) 349 return en; 350 351 return NULL; 352 } 353 354 355 /* 356 * Create or update an ip_vs_lblcr_entry, which is a mapping of a destination 357 * IP address to a server. Called under spin lock. 358 */ 359 static inline struct ip_vs_lblcr_entry * ip_vs_lblcr_new(struct ip_vs_lblcr_table * tbl,const union nf_inet_addr * daddr,u16 af,struct ip_vs_dest * dest)360 ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, const union nf_inet_addr *daddr, 361 u16 af, struct ip_vs_dest *dest) 362 { 363 struct ip_vs_lblcr_entry *en; 364 365 en = ip_vs_lblcr_get(af, tbl, daddr); 366 if (!en) { 367 en = kmalloc(sizeof(*en), GFP_ATOMIC); 368 if (!en) 369 return NULL; 370 371 en->af = af; 372 ip_vs_addr_copy(af, &en->addr, daddr); 373 en->lastuse = jiffies; 374 375 /* initialize its dest set */ 376 atomic_set(&(en->set.size), 0); 377 INIT_LIST_HEAD(&en->set.list); 378 379 ip_vs_dest_set_insert(&en->set, dest, false); 380 381 ip_vs_lblcr_hash(tbl, en); 382 return en; 383 } 384 385 ip_vs_dest_set_insert(&en->set, dest, true); 386 387 return en; 388 } 389 390 391 /* 392 * Flush all the entries of the specified table. 393 */ ip_vs_lblcr_flush(struct ip_vs_service * svc)394 static void ip_vs_lblcr_flush(struct ip_vs_service *svc) 395 { 396 struct ip_vs_lblcr_table *tbl = svc->sched_data; 397 int i; 398 struct ip_vs_lblcr_entry *en; 399 struct hlist_node *next; 400 401 spin_lock_bh(&svc->sched_lock); 402 tbl->dead = true; 403 for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) { 404 hlist_for_each_entry_safe(en, next, &tbl->bucket[i], list) { 405 ip_vs_lblcr_free(en); 406 } 407 } 408 spin_unlock_bh(&svc->sched_lock); 409 } 410 sysctl_lblcr_expiration(struct ip_vs_service * svc)411 static int sysctl_lblcr_expiration(struct ip_vs_service *svc) 412 { 413 #ifdef CONFIG_SYSCTL 414 return svc->ipvs->sysctl_lblcr_expiration; 415 #else 416 return DEFAULT_EXPIRATION; 417 #endif 418 } 419 ip_vs_lblcr_full_check(struct ip_vs_service * svc)420 static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc) 421 { 422 struct ip_vs_lblcr_table *tbl = svc->sched_data; 423 unsigned long now = jiffies; 424 int i, j; 425 struct ip_vs_lblcr_entry *en; 426 struct hlist_node *next; 427 428 for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) { 429 j = (j + 1) & IP_VS_LBLCR_TAB_MASK; 430 431 spin_lock(&svc->sched_lock); 432 hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) { 433 if (time_after(en->lastuse + 434 sysctl_lblcr_expiration(svc), now)) 435 continue; 436 437 ip_vs_lblcr_free(en); 438 atomic_dec(&tbl->entries); 439 } 440 spin_unlock(&svc->sched_lock); 441 } 442 tbl->rover = j; 443 } 444 445 446 /* 447 * Periodical timer handler for IPVS lblcr table 448 * It is used to collect stale entries when the number of entries 449 * exceeds the maximum size of the table. 450 * 451 * Fixme: we probably need more complicated algorithm to collect 452 * entries that have not been used for a long time even 453 * if the number of entries doesn't exceed the maximum size 454 * of the table. 455 * The full expiration check is for this purpose now. 456 */ ip_vs_lblcr_check_expire(struct timer_list * t)457 static void ip_vs_lblcr_check_expire(struct timer_list *t) 458 { 459 struct ip_vs_lblcr_table *tbl = from_timer(tbl, t, periodic_timer); 460 struct ip_vs_service *svc = tbl->svc; 461 unsigned long now = jiffies; 462 int goal; 463 int i, j; 464 struct ip_vs_lblcr_entry *en; 465 struct hlist_node *next; 466 467 if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { 468 /* do full expiration check */ 469 ip_vs_lblcr_full_check(svc); 470 tbl->counter = 1; 471 goto out; 472 } 473 474 if (atomic_read(&tbl->entries) <= tbl->max_size) { 475 tbl->counter++; 476 goto out; 477 } 478 479 goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3; 480 if (goal > tbl->max_size/2) 481 goal = tbl->max_size/2; 482 483 for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) { 484 j = (j + 1) & IP_VS_LBLCR_TAB_MASK; 485 486 spin_lock(&svc->sched_lock); 487 hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) { 488 if (time_before(now, en->lastuse+ENTRY_TIMEOUT)) 489 continue; 490 491 ip_vs_lblcr_free(en); 492 atomic_dec(&tbl->entries); 493 goal--; 494 } 495 spin_unlock(&svc->sched_lock); 496 if (goal <= 0) 497 break; 498 } 499 tbl->rover = j; 500 501 out: 502 mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL); 503 } 504 ip_vs_lblcr_init_svc(struct ip_vs_service * svc)505 static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) 506 { 507 int i; 508 struct ip_vs_lblcr_table *tbl; 509 510 /* 511 * Allocate the ip_vs_lblcr_table for this service 512 */ 513 tbl = kmalloc(sizeof(*tbl), GFP_KERNEL); 514 if (tbl == NULL) 515 return -ENOMEM; 516 517 svc->sched_data = tbl; 518 IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) allocated for " 519 "current service\n", sizeof(*tbl)); 520 521 /* 522 * Initialize the hash buckets 523 */ 524 for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) { 525 INIT_HLIST_HEAD(&tbl->bucket[i]); 526 } 527 tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16; 528 tbl->rover = 0; 529 tbl->counter = 1; 530 tbl->dead = false; 531 tbl->svc = svc; 532 atomic_set(&tbl->entries, 0); 533 534 /* 535 * Hook periodic timer for garbage collection 536 */ 537 timer_setup(&tbl->periodic_timer, ip_vs_lblcr_check_expire, 0); 538 mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL); 539 540 return 0; 541 } 542 543 ip_vs_lblcr_done_svc(struct ip_vs_service * svc)544 static void ip_vs_lblcr_done_svc(struct ip_vs_service *svc) 545 { 546 struct ip_vs_lblcr_table *tbl = svc->sched_data; 547 548 /* remove periodic timer */ 549 timer_shutdown_sync(&tbl->periodic_timer); 550 551 /* got to clean up table entries here */ 552 ip_vs_lblcr_flush(svc); 553 554 /* release the table itself */ 555 kfree_rcu(tbl, rcu_head); 556 IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) released\n", 557 sizeof(*tbl)); 558 } 559 560 561 static inline struct ip_vs_dest * __ip_vs_lblcr_schedule(struct ip_vs_service * svc)562 __ip_vs_lblcr_schedule(struct ip_vs_service *svc) 563 { 564 struct ip_vs_dest *dest, *least; 565 int loh, doh; 566 567 /* 568 * We use the following formula to estimate the load: 569 * (dest overhead) / dest->weight 570 * 571 * Remember -- no floats in kernel mode!!! 572 * The comparison of h1*w2 > h2*w1 is equivalent to that of 573 * h1/w1 > h2/w2 574 * if every weight is larger than zero. 575 * 576 * The server with weight=0 is quiesced and will not receive any 577 * new connection. 578 */ 579 list_for_each_entry_rcu(dest, &svc->destinations, n_list) { 580 if (dest->flags & IP_VS_DEST_F_OVERLOAD) 581 continue; 582 583 if (atomic_read(&dest->weight) > 0) { 584 least = dest; 585 loh = ip_vs_dest_conn_overhead(least); 586 goto nextstage; 587 } 588 } 589 return NULL; 590 591 /* 592 * Find the destination with the least load. 593 */ 594 nextstage: 595 list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) { 596 if (dest->flags & IP_VS_DEST_F_OVERLOAD) 597 continue; 598 599 doh = ip_vs_dest_conn_overhead(dest); 600 if ((__s64)loh * atomic_read(&dest->weight) > 601 (__s64)doh * atomic_read(&least->weight)) { 602 least = dest; 603 loh = doh; 604 } 605 } 606 607 IP_VS_DBG_BUF(6, "LBLCR: server %s:%d " 608 "activeconns %d refcnt %d weight %d overhead %d\n", 609 IP_VS_DBG_ADDR(least->af, &least->addr), 610 ntohs(least->port), 611 atomic_read(&least->activeconns), 612 refcount_read(&least->refcnt), 613 atomic_read(&least->weight), loh); 614 615 return least; 616 } 617 618 619 /* 620 * If this destination server is overloaded and there is a less loaded 621 * server, then return true. 622 */ 623 static inline int is_overloaded(struct ip_vs_dest * dest,struct ip_vs_service * svc)624 is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) 625 { 626 if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) { 627 struct ip_vs_dest *d; 628 629 list_for_each_entry_rcu(d, &svc->destinations, n_list) { 630 if (atomic_read(&d->activeconns)*2 631 < atomic_read(&d->weight)) { 632 return 1; 633 } 634 } 635 } 636 return 0; 637 } 638 639 640 /* 641 * Locality-Based (weighted) Least-Connection scheduling 642 */ 643 static struct ip_vs_dest * ip_vs_lblcr_schedule(struct ip_vs_service * svc,const struct sk_buff * skb,struct ip_vs_iphdr * iph)644 ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, 645 struct ip_vs_iphdr *iph) 646 { 647 struct ip_vs_lblcr_table *tbl = svc->sched_data; 648 struct ip_vs_dest *dest; 649 struct ip_vs_lblcr_entry *en; 650 651 IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); 652 653 /* First look in our cache */ 654 en = ip_vs_lblcr_get(svc->af, tbl, &iph->daddr); 655 if (en) { 656 en->lastuse = jiffies; 657 658 /* Get the least loaded destination */ 659 dest = ip_vs_dest_set_min(&en->set); 660 661 /* More than one destination + enough time passed by, cleanup */ 662 if (atomic_read(&en->set.size) > 1 && 663 time_after(jiffies, en->set.lastmod + 664 sysctl_lblcr_expiration(svc))) { 665 spin_lock_bh(&svc->sched_lock); 666 if (atomic_read(&en->set.size) > 1) { 667 struct ip_vs_dest *m; 668 669 m = ip_vs_dest_set_max(&en->set); 670 if (m) 671 ip_vs_dest_set_erase(&en->set, m); 672 } 673 spin_unlock_bh(&svc->sched_lock); 674 } 675 676 /* If the destination is not overloaded, use it */ 677 if (dest && !is_overloaded(dest, svc)) 678 goto out; 679 680 /* The cache entry is invalid, time to schedule */ 681 dest = __ip_vs_lblcr_schedule(svc); 682 if (!dest) { 683 ip_vs_scheduler_err(svc, "no destination available"); 684 return NULL; 685 } 686 687 /* Update our cache entry */ 688 spin_lock_bh(&svc->sched_lock); 689 if (!tbl->dead) 690 ip_vs_dest_set_insert(&en->set, dest, true); 691 spin_unlock_bh(&svc->sched_lock); 692 goto out; 693 } 694 695 /* No cache entry, time to schedule */ 696 dest = __ip_vs_lblcr_schedule(svc); 697 if (!dest) { 698 IP_VS_DBG(1, "no destination available\n"); 699 return NULL; 700 } 701 702 /* If we fail to create a cache entry, we'll just use the valid dest */ 703 spin_lock_bh(&svc->sched_lock); 704 if (!tbl->dead) 705 ip_vs_lblcr_new(tbl, &iph->daddr, svc->af, dest); 706 spin_unlock_bh(&svc->sched_lock); 707 708 out: 709 IP_VS_DBG_BUF(6, "LBLCR: destination IP address %s --> server %s:%d\n", 710 IP_VS_DBG_ADDR(svc->af, &iph->daddr), 711 IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port)); 712 713 return dest; 714 } 715 716 717 /* 718 * IPVS LBLCR Scheduler structure 719 */ 720 static struct ip_vs_scheduler ip_vs_lblcr_scheduler = 721 { 722 .name = "lblcr", 723 .refcnt = ATOMIC_INIT(0), 724 .module = THIS_MODULE, 725 .n_list = LIST_HEAD_INIT(ip_vs_lblcr_scheduler.n_list), 726 .init_service = ip_vs_lblcr_init_svc, 727 .done_service = ip_vs_lblcr_done_svc, 728 .schedule = ip_vs_lblcr_schedule, 729 }; 730 731 /* 732 * per netns init. 733 */ 734 #ifdef CONFIG_SYSCTL __ip_vs_lblcr_init(struct net * net)735 static int __net_init __ip_vs_lblcr_init(struct net *net) 736 { 737 struct netns_ipvs *ipvs = net_ipvs(net); 738 size_t vars_table_size = ARRAY_SIZE(vs_vars_table); 739 740 if (!ipvs) 741 return -ENOENT; 742 743 if (!net_eq(net, &init_net)) { 744 ipvs->lblcr_ctl_table = kmemdup(vs_vars_table, 745 sizeof(vs_vars_table), 746 GFP_KERNEL); 747 if (ipvs->lblcr_ctl_table == NULL) 748 return -ENOMEM; 749 750 /* Don't export sysctls to unprivileged users */ 751 if (net->user_ns != &init_user_ns) 752 vars_table_size = 0; 753 } else 754 ipvs->lblcr_ctl_table = vs_vars_table; 755 ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION; 756 ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration; 757 758 ipvs->lblcr_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs", 759 ipvs->lblcr_ctl_table, 760 vars_table_size); 761 if (!ipvs->lblcr_ctl_header) { 762 if (!net_eq(net, &init_net)) 763 kfree(ipvs->lblcr_ctl_table); 764 return -ENOMEM; 765 } 766 767 return 0; 768 } 769 __ip_vs_lblcr_exit(struct net * net)770 static void __net_exit __ip_vs_lblcr_exit(struct net *net) 771 { 772 struct netns_ipvs *ipvs = net_ipvs(net); 773 774 unregister_net_sysctl_table(ipvs->lblcr_ctl_header); 775 776 if (!net_eq(net, &init_net)) 777 kfree(ipvs->lblcr_ctl_table); 778 } 779 780 #else 781 __ip_vs_lblcr_init(struct net * net)782 static int __net_init __ip_vs_lblcr_init(struct net *net) { return 0; } __ip_vs_lblcr_exit(struct net * net)783 static void __net_exit __ip_vs_lblcr_exit(struct net *net) { } 784 785 #endif 786 787 static struct pernet_operations ip_vs_lblcr_ops = { 788 .init = __ip_vs_lblcr_init, 789 .exit = __ip_vs_lblcr_exit, 790 }; 791 ip_vs_lblcr_init(void)792 static int __init ip_vs_lblcr_init(void) 793 { 794 int ret; 795 796 ret = register_pernet_subsys(&ip_vs_lblcr_ops); 797 if (ret) 798 return ret; 799 800 ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler); 801 if (ret) 802 unregister_pernet_subsys(&ip_vs_lblcr_ops); 803 return ret; 804 } 805 ip_vs_lblcr_cleanup(void)806 static void __exit ip_vs_lblcr_cleanup(void) 807 { 808 unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler); 809 unregister_pernet_subsys(&ip_vs_lblcr_ops); 810 rcu_barrier(); 811 } 812 813 814 module_init(ip_vs_lblcr_init); 815 module_exit(ip_vs_lblcr_cleanup); 816 MODULE_LICENSE("GPL"); 817 MODULE_DESCRIPTION("ipvs locality-based least-connection with replication scheduler"); 818