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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * IPVS: Locality-Based Least-Connection scheduling module | |
3 | * | |
1da177e4 LT |
4 | * Authors: Wensong Zhang <wensong@gnuchina.org> |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * Changes: | |
12 | * Martin Hamilton : fixed the terrible locking bugs | |
13 | * *lock(tbl->lock) ==> *lock(&tbl->lock) | |
421f91d2 | 14 | * Wensong Zhang : fixed the uninitialized tbl->lock bug |
1da177e4 LT |
15 | * Wensong Zhang : added doing full expiration check to |
16 | * collect stale entries of 24+ hours when | |
17 | * no partial expire check in a half hour | |
18 | * Julian Anastasov : replaced del_timer call with del_timer_sync | |
19 | * to avoid the possible race between timer | |
20 | * handler and del_timer thread in SMP | |
21 | * | |
22 | */ | |
23 | ||
24 | /* | |
25 | * The lblc algorithm is as follows (pseudo code): | |
26 | * | |
27 | * if cachenode[dest_ip] is null then | |
28 | * n, cachenode[dest_ip] <- {weighted least-conn node}; | |
29 | * else | |
30 | * n <- cachenode[dest_ip]; | |
31 | * if (n is dead) OR | |
32 | * (n.conns>n.weight AND | |
33 | * there is a node m with m.conns<m.weight/2) then | |
34 | * n, cachenode[dest_ip] <- {weighted least-conn node}; | |
35 | * | |
36 | * return n; | |
37 | * | |
38 | * Thanks must go to Wenzhuo Zhang for talking WCCP to me and pushing | |
39 | * me to write this module. | |
40 | */ | |
41 | ||
9aada7ac HE |
42 | #define KMSG_COMPONENT "IPVS" |
43 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
44 | ||
14c85021 | 45 | #include <linux/ip.h> |
5a0e3ad6 | 46 | #include <linux/slab.h> |
1da177e4 LT |
47 | #include <linux/module.h> |
48 | #include <linux/kernel.h> | |
14c85021 | 49 | #include <linux/skbuff.h> |
d7fe0f24 | 50 | #include <linux/jiffies.h> |
1da177e4 LT |
51 | |
52 | /* for sysctl */ | |
53 | #include <linux/fs.h> | |
54 | #include <linux/sysctl.h> | |
55 | ||
56 | #include <net/ip_vs.h> | |
57 | ||
58 | ||
59 | /* | |
60 | * It is for garbage collection of stale IPVS lblc entries, | |
61 | * when the table is full. | |
62 | */ | |
63 | #define CHECK_EXPIRE_INTERVAL (60*HZ) | |
64 | #define ENTRY_TIMEOUT (6*60*HZ) | |
65 | ||
b27d777e SH |
66 | #define DEFAULT_EXPIRATION (24*60*60*HZ) |
67 | ||
1da177e4 LT |
68 | /* |
69 | * It is for full expiration check. | |
70 | * When there is no partial expiration check (garbage collection) | |
71 | * in a half hour, do a full expiration check to collect stale | |
72 | * entries that haven't been touched for a day. | |
73 | */ | |
74 | #define COUNT_FOR_FULL_EXPIRATION 30 | |
1da177e4 LT |
75 | |
76 | ||
77 | /* | |
78 | * for IPVS lblc entry hash table | |
79 | */ | |
80 | #ifndef CONFIG_IP_VS_LBLC_TAB_BITS | |
81 | #define CONFIG_IP_VS_LBLC_TAB_BITS 10 | |
82 | #endif | |
83 | #define IP_VS_LBLC_TAB_BITS CONFIG_IP_VS_LBLC_TAB_BITS | |
84 | #define IP_VS_LBLC_TAB_SIZE (1 << IP_VS_LBLC_TAB_BITS) | |
85 | #define IP_VS_LBLC_TAB_MASK (IP_VS_LBLC_TAB_SIZE - 1) | |
86 | ||
87 | ||
88 | /* | |
89 | * IPVS lblc entry represents an association between destination | |
90 | * IP address and its destination server | |
91 | */ | |
92 | struct ip_vs_lblc_entry { | |
c2a4ffb7 | 93 | struct hlist_node list; |
44548375 JV |
94 | int af; /* address family */ |
95 | union nf_inet_addr addr; /* destination IP address */ | |
c2a4ffb7 | 96 | struct ip_vs_dest __rcu *dest; /* real server (cache) */ |
1da177e4 | 97 | unsigned long lastuse; /* last used time */ |
c2a4ffb7 | 98 | struct rcu_head rcu_head; |
1da177e4 LT |
99 | }; |
100 | ||
101 | ||
102 | /* | |
103 | * IPVS lblc hash table | |
104 | */ | |
105 | struct ip_vs_lblc_table { | |
c2a4ffb7 JA |
106 | struct rcu_head rcu_head; |
107 | struct hlist_head __rcu bucket[IP_VS_LBLC_TAB_SIZE]; /* hash bucket */ | |
108 | struct timer_list periodic_timer; /* collect stale entries */ | |
1da177e4 LT |
109 | atomic_t entries; /* number of entries */ |
110 | int max_size; /* maximum size of entries */ | |
1da177e4 LT |
111 | int rover; /* rover for expire check */ |
112 | int counter; /* counter for no expire */ | |
c2a4ffb7 | 113 | bool dead; |
1da177e4 LT |
114 | }; |
115 | ||
116 | ||
117 | /* | |
118 | * IPVS LBLC sysctl table | |
119 | */ | |
fb1de432 | 120 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
121 | static ctl_table vs_vars_table[] = { |
122 | { | |
1da177e4 | 123 | .procname = "lblc_expiration", |
b6e885dd | 124 | .data = NULL, |
1da177e4 | 125 | .maxlen = sizeof(int), |
e905a9ed | 126 | .mode = 0644, |
6d9f239a | 127 | .proc_handler = proc_dointvec_jiffies, |
1da177e4 | 128 | }, |
f8572d8f | 129 | { } |
1da177e4 | 130 | }; |
fb1de432 | 131 | #endif |
1da177e4 | 132 | |
1da177e4 LT |
133 | static inline void ip_vs_lblc_free(struct ip_vs_lblc_entry *en) |
134 | { | |
c2a4ffb7 JA |
135 | struct ip_vs_dest *dest; |
136 | ||
137 | hlist_del_rcu(&en->list); | |
1da177e4 | 138 | /* |
25985edc | 139 | * We don't kfree dest because it is referred either by its service |
1da177e4 LT |
140 | * or the trash dest list. |
141 | */ | |
c2a4ffb7 JA |
142 | dest = rcu_dereference_protected(en->dest, 1); |
143 | ip_vs_dest_put(dest); | |
144 | kfree_rcu(en, rcu_head); | |
1da177e4 LT |
145 | } |
146 | ||
147 | ||
148 | /* | |
149 | * Returns hash value for IPVS LBLC entry | |
150 | */ | |
95c96174 | 151 | static inline unsigned int |
44548375 | 152 | ip_vs_lblc_hashkey(int af, const union nf_inet_addr *addr) |
1da177e4 | 153 | { |
44548375 JV |
154 | __be32 addr_fold = addr->ip; |
155 | ||
156 | #ifdef CONFIG_IP_VS_IPV6 | |
157 | if (af == AF_INET6) | |
158 | addr_fold = addr->ip6[0]^addr->ip6[1]^ | |
159 | addr->ip6[2]^addr->ip6[3]; | |
160 | #endif | |
161 | return (ntohl(addr_fold)*2654435761UL) & IP_VS_LBLC_TAB_MASK; | |
1da177e4 LT |
162 | } |
163 | ||
164 | ||
165 | /* | |
166 | * Hash an entry in the ip_vs_lblc_table. | |
167 | * returns bool success. | |
168 | */ | |
39ac50d0 | 169 | static void |
1da177e4 LT |
170 | ip_vs_lblc_hash(struct ip_vs_lblc_table *tbl, struct ip_vs_lblc_entry *en) |
171 | { | |
95c96174 | 172 | unsigned int hash = ip_vs_lblc_hashkey(en->af, &en->addr); |
1da177e4 | 173 | |
c2a4ffb7 | 174 | hlist_add_head_rcu(&en->list, &tbl->bucket[hash]); |
1da177e4 | 175 | atomic_inc(&tbl->entries); |
1da177e4 LT |
176 | } |
177 | ||
178 | ||
c2a4ffb7 | 179 | /* Get ip_vs_lblc_entry associated with supplied parameters. */ |
1da177e4 | 180 | static inline struct ip_vs_lblc_entry * |
44548375 JV |
181 | ip_vs_lblc_get(int af, struct ip_vs_lblc_table *tbl, |
182 | const union nf_inet_addr *addr) | |
1da177e4 | 183 | { |
95c96174 | 184 | unsigned int hash = ip_vs_lblc_hashkey(af, addr); |
1da177e4 LT |
185 | struct ip_vs_lblc_entry *en; |
186 | ||
c2a4ffb7 | 187 | hlist_for_each_entry_rcu(en, &tbl->bucket[hash], list) |
44548375 | 188 | if (ip_vs_addr_equal(af, &en->addr, addr)) |
39ac50d0 | 189 | return en; |
1da177e4 | 190 | |
39ac50d0 SW |
191 | return NULL; |
192 | } | |
1da177e4 | 193 | |
39ac50d0 SW |
194 | |
195 | /* | |
196 | * Create or update an ip_vs_lblc_entry, which is a mapping of a destination IP | |
ba3a3ce1 | 197 | * address to a server. Called under spin lock. |
39ac50d0 SW |
198 | */ |
199 | static inline struct ip_vs_lblc_entry * | |
44548375 | 200 | ip_vs_lblc_new(struct ip_vs_lblc_table *tbl, const union nf_inet_addr *daddr, |
39ac50d0 SW |
201 | struct ip_vs_dest *dest) |
202 | { | |
203 | struct ip_vs_lblc_entry *en; | |
204 | ||
44548375 | 205 | en = ip_vs_lblc_get(dest->af, tbl, daddr); |
39ac50d0 SW |
206 | if (!en) { |
207 | en = kmalloc(sizeof(*en), GFP_ATOMIC); | |
0a9ee813 | 208 | if (!en) |
39ac50d0 | 209 | return NULL; |
1da177e4 | 210 | |
44548375 JV |
211 | en->af = dest->af; |
212 | ip_vs_addr_copy(dest->af, &en->addr, daddr); | |
39ac50d0 | 213 | en->lastuse = jiffies; |
1da177e4 | 214 | |
c2a4ffb7 JA |
215 | ip_vs_dest_hold(dest); |
216 | RCU_INIT_POINTER(en->dest, dest); | |
39ac50d0 SW |
217 | |
218 | ip_vs_lblc_hash(tbl, en); | |
c2a4ffb7 JA |
219 | } else { |
220 | struct ip_vs_dest *old_dest; | |
221 | ||
222 | old_dest = rcu_dereference_protected(en->dest, 1); | |
223 | if (old_dest != dest) { | |
224 | ip_vs_dest_put(old_dest); | |
225 | ip_vs_dest_hold(dest); | |
226 | /* No ordering constraints for refcnt */ | |
227 | RCU_INIT_POINTER(en->dest, dest); | |
228 | } | |
39ac50d0 SW |
229 | } |
230 | ||
231 | return en; | |
1da177e4 LT |
232 | } |
233 | ||
234 | ||
235 | /* | |
236 | * Flush all the entries of the specified table. | |
237 | */ | |
c2a4ffb7 | 238 | static void ip_vs_lblc_flush(struct ip_vs_service *svc) |
1da177e4 | 239 | { |
c2a4ffb7 JA |
240 | struct ip_vs_lblc_table *tbl = svc->sched_data; |
241 | struct ip_vs_lblc_entry *en; | |
242 | struct hlist_node *next; | |
39ac50d0 | 243 | int i; |
1da177e4 | 244 | |
ba3a3ce1 | 245 | spin_lock_bh(&svc->sched_lock); |
c2a4ffb7 | 246 | tbl->dead = 1; |
1da177e4 | 247 | for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) { |
c2a4ffb7 | 248 | hlist_for_each_entry_safe(en, next, &tbl->bucket[i], list) { |
1da177e4 LT |
249 | ip_vs_lblc_free(en); |
250 | atomic_dec(&tbl->entries); | |
251 | } | |
1da177e4 | 252 | } |
ba3a3ce1 | 253 | spin_unlock_bh(&svc->sched_lock); |
1da177e4 LT |
254 | } |
255 | ||
b27d777e SH |
256 | static int sysctl_lblc_expiration(struct ip_vs_service *svc) |
257 | { | |
258 | #ifdef CONFIG_SYSCTL | |
259 | struct netns_ipvs *ipvs = net_ipvs(svc->net); | |
260 | return ipvs->sysctl_lblc_expiration; | |
261 | #else | |
262 | return DEFAULT_EXPIRATION; | |
263 | #endif | |
264 | } | |
1da177e4 | 265 | |
39ac50d0 | 266 | static inline void ip_vs_lblc_full_check(struct ip_vs_service *svc) |
1da177e4 | 267 | { |
39ac50d0 | 268 | struct ip_vs_lblc_table *tbl = svc->sched_data; |
c2a4ffb7 JA |
269 | struct ip_vs_lblc_entry *en; |
270 | struct hlist_node *next; | |
1da177e4 LT |
271 | unsigned long now = jiffies; |
272 | int i, j; | |
1da177e4 LT |
273 | |
274 | for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) { | |
275 | j = (j + 1) & IP_VS_LBLC_TAB_MASK; | |
276 | ||
ba3a3ce1 | 277 | spin_lock(&svc->sched_lock); |
c2a4ffb7 | 278 | hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) { |
e905a9ed | 279 | if (time_before(now, |
b6e885dd | 280 | en->lastuse + |
b27d777e | 281 | sysctl_lblc_expiration(svc))) |
1da177e4 LT |
282 | continue; |
283 | ||
284 | ip_vs_lblc_free(en); | |
285 | atomic_dec(&tbl->entries); | |
286 | } | |
ba3a3ce1 | 287 | spin_unlock(&svc->sched_lock); |
1da177e4 LT |
288 | } |
289 | tbl->rover = j; | |
290 | } | |
291 | ||
292 | ||
293 | /* | |
294 | * Periodical timer handler for IPVS lblc table | |
295 | * It is used to collect stale entries when the number of entries | |
296 | * exceeds the maximum size of the table. | |
297 | * | |
298 | * Fixme: we probably need more complicated algorithm to collect | |
299 | * entries that have not been used for a long time even | |
300 | * if the number of entries doesn't exceed the maximum size | |
301 | * of the table. | |
302 | * The full expiration check is for this purpose now. | |
303 | */ | |
304 | static void ip_vs_lblc_check_expire(unsigned long data) | |
305 | { | |
39ac50d0 SW |
306 | struct ip_vs_service *svc = (struct ip_vs_service *) data; |
307 | struct ip_vs_lblc_table *tbl = svc->sched_data; | |
1da177e4 LT |
308 | unsigned long now = jiffies; |
309 | int goal; | |
310 | int i, j; | |
c2a4ffb7 JA |
311 | struct ip_vs_lblc_entry *en; |
312 | struct hlist_node *next; | |
1da177e4 | 313 | |
1da177e4 LT |
314 | if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { |
315 | /* do full expiration check */ | |
39ac50d0 | 316 | ip_vs_lblc_full_check(svc); |
1da177e4 LT |
317 | tbl->counter = 1; |
318 | goto out; | |
319 | } | |
320 | ||
321 | if (atomic_read(&tbl->entries) <= tbl->max_size) { | |
322 | tbl->counter++; | |
323 | goto out; | |
324 | } | |
325 | ||
326 | goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3; | |
327 | if (goal > tbl->max_size/2) | |
328 | goal = tbl->max_size/2; | |
329 | ||
330 | for (i=0, j=tbl->rover; i<IP_VS_LBLC_TAB_SIZE; i++) { | |
331 | j = (j + 1) & IP_VS_LBLC_TAB_MASK; | |
332 | ||
ba3a3ce1 | 333 | spin_lock(&svc->sched_lock); |
c2a4ffb7 | 334 | hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) { |
1da177e4 LT |
335 | if (time_before(now, en->lastuse + ENTRY_TIMEOUT)) |
336 | continue; | |
337 | ||
338 | ip_vs_lblc_free(en); | |
339 | atomic_dec(&tbl->entries); | |
340 | goal--; | |
341 | } | |
ba3a3ce1 | 342 | spin_unlock(&svc->sched_lock); |
1da177e4 LT |
343 | if (goal <= 0) |
344 | break; | |
345 | } | |
346 | tbl->rover = j; | |
347 | ||
348 | out: | |
349 | mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL); | |
350 | } | |
351 | ||
352 | ||
353 | static int ip_vs_lblc_init_svc(struct ip_vs_service *svc) | |
354 | { | |
355 | int i; | |
356 | struct ip_vs_lblc_table *tbl; | |
357 | ||
358 | /* | |
359 | * Allocate the ip_vs_lblc_table for this service | |
360 | */ | |
748d845c | 361 | tbl = kmalloc(sizeof(*tbl), GFP_KERNEL); |
0a9ee813 | 362 | if (tbl == NULL) |
1da177e4 | 363 | return -ENOMEM; |
0a9ee813 | 364 | |
1da177e4 LT |
365 | svc->sched_data = tbl; |
366 | IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) allocated for " | |
39ac50d0 | 367 | "current service\n", sizeof(*tbl)); |
1da177e4 LT |
368 | |
369 | /* | |
370 | * Initialize the hash buckets | |
371 | */ | |
372 | for (i=0; i<IP_VS_LBLC_TAB_SIZE; i++) { | |
c2a4ffb7 | 373 | INIT_HLIST_HEAD(&tbl->bucket[i]); |
1da177e4 | 374 | } |
1da177e4 LT |
375 | tbl->max_size = IP_VS_LBLC_TAB_SIZE*16; |
376 | tbl->rover = 0; | |
377 | tbl->counter = 1; | |
c2a4ffb7 | 378 | tbl->dead = 0; |
1da177e4 LT |
379 | |
380 | /* | |
381 | * Hook periodic timer for garbage collection | |
382 | */ | |
b24b8a24 | 383 | setup_timer(&tbl->periodic_timer, ip_vs_lblc_check_expire, |
39ac50d0 SW |
384 | (unsigned long)svc); |
385 | mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL); | |
1da177e4 LT |
386 | |
387 | return 0; | |
388 | } | |
389 | ||
390 | ||
ed3ffc4e | 391 | static void ip_vs_lblc_done_svc(struct ip_vs_service *svc) |
1da177e4 LT |
392 | { |
393 | struct ip_vs_lblc_table *tbl = svc->sched_data; | |
394 | ||
395 | /* remove periodic timer */ | |
396 | del_timer_sync(&tbl->periodic_timer); | |
397 | ||
398 | /* got to clean up table entries here */ | |
c2a4ffb7 | 399 | ip_vs_lblc_flush(svc); |
1da177e4 LT |
400 | |
401 | /* release the table itself */ | |
c2a4ffb7 | 402 | kfree_rcu(tbl, rcu_head); |
1da177e4 | 403 | IP_VS_DBG(6, "LBLC hash table (memory=%Zdbytes) released\n", |
39ac50d0 | 404 | sizeof(*tbl)); |
1da177e4 LT |
405 | } |
406 | ||
407 | ||
1da177e4 | 408 | static inline struct ip_vs_dest * |
44548375 | 409 | __ip_vs_lblc_schedule(struct ip_vs_service *svc) |
1da177e4 LT |
410 | { |
411 | struct ip_vs_dest *dest, *least; | |
412 | int loh, doh; | |
413 | ||
414 | /* | |
b552f7e3 | 415 | * We use the following formula to estimate the load: |
1da177e4 LT |
416 | * (dest overhead) / dest->weight |
417 | * | |
418 | * Remember -- no floats in kernel mode!!! | |
419 | * The comparison of h1*w2 > h2*w1 is equivalent to that of | |
420 | * h1/w1 > h2/w2 | |
421 | * if every weight is larger than zero. | |
422 | * | |
423 | * The server with weight=0 is quiesced and will not receive any | |
424 | * new connection. | |
425 | */ | |
c2a4ffb7 | 426 | list_for_each_entry_rcu(dest, &svc->destinations, n_list) { |
1da177e4 LT |
427 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) |
428 | continue; | |
429 | if (atomic_read(&dest->weight) > 0) { | |
430 | least = dest; | |
b552f7e3 | 431 | loh = ip_vs_dest_conn_overhead(least); |
1da177e4 LT |
432 | goto nextstage; |
433 | } | |
434 | } | |
435 | return NULL; | |
436 | ||
437 | /* | |
438 | * Find the destination with the least load. | |
439 | */ | |
440 | nextstage: | |
c2a4ffb7 | 441 | list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) { |
1da177e4 LT |
442 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) |
443 | continue; | |
444 | ||
b552f7e3 | 445 | doh = ip_vs_dest_conn_overhead(dest); |
1da177e4 LT |
446 | if (loh * atomic_read(&dest->weight) > |
447 | doh * atomic_read(&least->weight)) { | |
448 | least = dest; | |
449 | loh = doh; | |
450 | } | |
451 | } | |
452 | ||
44548375 JV |
453 | IP_VS_DBG_BUF(6, "LBLC: server %s:%d " |
454 | "activeconns %d refcnt %d weight %d overhead %d\n", | |
455 | IP_VS_DBG_ADDR(least->af, &least->addr), | |
456 | ntohs(least->port), | |
457 | atomic_read(&least->activeconns), | |
458 | atomic_read(&least->refcnt), | |
459 | atomic_read(&least->weight), loh); | |
1da177e4 LT |
460 | |
461 | return least; | |
462 | } | |
463 | ||
464 | ||
465 | /* | |
466 | * If this destination server is overloaded and there is a less loaded | |
467 | * server, then return true. | |
468 | */ | |
469 | static inline int | |
470 | is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) | |
471 | { | |
472 | if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) { | |
473 | struct ip_vs_dest *d; | |
474 | ||
c2a4ffb7 | 475 | list_for_each_entry_rcu(d, &svc->destinations, n_list) { |
1da177e4 LT |
476 | if (atomic_read(&d->activeconns)*2 |
477 | < atomic_read(&d->weight)) { | |
478 | return 1; | |
479 | } | |
480 | } | |
481 | } | |
482 | return 0; | |
483 | } | |
484 | ||
485 | ||
486 | /* | |
487 | * Locality-Based (weighted) Least-Connection scheduling | |
488 | */ | |
489 | static struct ip_vs_dest * | |
490 | ip_vs_lblc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) | |
491 | { | |
39ac50d0 | 492 | struct ip_vs_lblc_table *tbl = svc->sched_data; |
44548375 | 493 | struct ip_vs_iphdr iph; |
39ac50d0 SW |
494 | struct ip_vs_dest *dest = NULL; |
495 | struct ip_vs_lblc_entry *en; | |
1da177e4 | 496 | |
63dca2c0 | 497 | ip_vs_fill_iph_addr_only(svc->af, skb, &iph); |
44548375 | 498 | |
1e3e238e | 499 | IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); |
1da177e4 | 500 | |
39ac50d0 | 501 | /* First look in our cache */ |
44548375 | 502 | en = ip_vs_lblc_get(svc->af, tbl, &iph.daddr); |
39ac50d0 SW |
503 | if (en) { |
504 | /* We only hold a read lock, but this is atomic */ | |
505 | en->lastuse = jiffies; | |
506 | ||
507 | /* | |
508 | * If the destination is not available, i.e. it's in the trash, | |
509 | * we must ignore it, as it may be removed from under our feet, | |
510 | * if someone drops our reference count. Our caller only makes | |
511 | * sure that destinations, that are not in the trash, are not | |
512 | * moved to the trash, while we are scheduling. But anyone can | |
513 | * free up entries from the trash at any time. | |
514 | */ | |
515 | ||
c2a4ffb7 JA |
516 | dest = rcu_dereference(en->dest); |
517 | if ((dest->flags & IP_VS_DEST_F_AVAILABLE) && | |
518 | atomic_read(&dest->weight) > 0 && !is_overloaded(dest, svc)) | |
519 | goto out; | |
39ac50d0 | 520 | } |
39ac50d0 SW |
521 | |
522 | /* No cache entry or it is invalid, time to schedule */ | |
44548375 | 523 | dest = __ip_vs_lblc_schedule(svc); |
39ac50d0 | 524 | if (!dest) { |
41ac51ee | 525 | ip_vs_scheduler_err(svc, "no destination available"); |
39ac50d0 | 526 | return NULL; |
1da177e4 | 527 | } |
1da177e4 | 528 | |
39ac50d0 | 529 | /* If we fail to create a cache entry, we'll just use the valid dest */ |
ba3a3ce1 | 530 | spin_lock(&svc->sched_lock); |
c2a4ffb7 JA |
531 | if (!tbl->dead) |
532 | ip_vs_lblc_new(tbl, &iph.daddr, dest); | |
ba3a3ce1 | 533 | spin_unlock(&svc->sched_lock); |
39ac50d0 SW |
534 | |
535 | out: | |
44548375 JV |
536 | IP_VS_DBG_BUF(6, "LBLC: destination IP address %s --> server %s:%d\n", |
537 | IP_VS_DBG_ADDR(svc->af, &iph.daddr), | |
538 | IP_VS_DBG_ADDR(svc->af, &dest->addr), ntohs(dest->port)); | |
1da177e4 LT |
539 | |
540 | return dest; | |
541 | } | |
542 | ||
543 | ||
544 | /* | |
545 | * IPVS LBLC Scheduler structure | |
546 | */ | |
547 | static struct ip_vs_scheduler ip_vs_lblc_scheduler = | |
548 | { | |
549 | .name = "lblc", | |
550 | .refcnt = ATOMIC_INIT(0), | |
551 | .module = THIS_MODULE, | |
d149ccc9 | 552 | .n_list = LIST_HEAD_INIT(ip_vs_lblc_scheduler.n_list), |
1da177e4 LT |
553 | .init_service = ip_vs_lblc_init_svc, |
554 | .done_service = ip_vs_lblc_done_svc, | |
1da177e4 LT |
555 | .schedule = ip_vs_lblc_schedule, |
556 | }; | |
557 | ||
61b1ab45 HS |
558 | /* |
559 | * per netns init. | |
560 | */ | |
fb1de432 | 561 | #ifdef CONFIG_SYSCTL |
61b1ab45 HS |
562 | static int __net_init __ip_vs_lblc_init(struct net *net) |
563 | { | |
b6e885dd HS |
564 | struct netns_ipvs *ipvs = net_ipvs(net); |
565 | ||
4b984cd5 HS |
566 | if (!ipvs) |
567 | return -ENOENT; | |
568 | ||
b6e885dd HS |
569 | if (!net_eq(net, &init_net)) { |
570 | ipvs->lblc_ctl_table = kmemdup(vs_vars_table, | |
571 | sizeof(vs_vars_table), | |
572 | GFP_KERNEL); | |
573 | if (ipvs->lblc_ctl_table == NULL) | |
0443929f | 574 | return -ENOMEM; |
464dc801 EB |
575 | |
576 | /* Don't export sysctls to unprivileged users */ | |
577 | if (net->user_ns != &init_user_ns) | |
578 | ipvs->lblc_ctl_table[0].procname = NULL; | |
579 | ||
b6e885dd HS |
580 | } else |
581 | ipvs->lblc_ctl_table = vs_vars_table; | |
b27d777e | 582 | ipvs->sysctl_lblc_expiration = DEFAULT_EXPIRATION; |
b6e885dd HS |
583 | ipvs->lblc_ctl_table[0].data = &ipvs->sysctl_lblc_expiration; |
584 | ||
585 | ipvs->lblc_ctl_header = | |
ec8f23ce | 586 | register_net_sysctl(net, "net/ipv4/vs", ipvs->lblc_ctl_table); |
0443929f SH |
587 | if (!ipvs->lblc_ctl_header) { |
588 | if (!net_eq(net, &init_net)) | |
e5ef39ed | 589 | kfree(ipvs->lblc_ctl_table); |
0443929f SH |
590 | return -ENOMEM; |
591 | } | |
61b1ab45 HS |
592 | |
593 | return 0; | |
594 | } | |
595 | ||
596 | static void __net_exit __ip_vs_lblc_exit(struct net *net) | |
597 | { | |
b6e885dd HS |
598 | struct netns_ipvs *ipvs = net_ipvs(net); |
599 | ||
600 | unregister_net_sysctl_table(ipvs->lblc_ctl_header); | |
61b1ab45 | 601 | |
b6e885dd HS |
602 | if (!net_eq(net, &init_net)) |
603 | kfree(ipvs->lblc_ctl_table); | |
61b1ab45 HS |
604 | } |
605 | ||
fb1de432 SH |
606 | #else |
607 | ||
608 | static int __net_init __ip_vs_lblc_init(struct net *net) { return 0; } | |
609 | static void __net_exit __ip_vs_lblc_exit(struct net *net) { } | |
610 | ||
611 | #endif | |
612 | ||
61b1ab45 HS |
613 | static struct pernet_operations ip_vs_lblc_ops = { |
614 | .init = __ip_vs_lblc_init, | |
615 | .exit = __ip_vs_lblc_exit, | |
616 | }; | |
1da177e4 LT |
617 | |
618 | static int __init ip_vs_lblc_init(void) | |
619 | { | |
a014bc8f PE |
620 | int ret; |
621 | ||
61b1ab45 HS |
622 | ret = register_pernet_subsys(&ip_vs_lblc_ops); |
623 | if (ret) | |
624 | return ret; | |
625 | ||
a014bc8f PE |
626 | ret = register_ip_vs_scheduler(&ip_vs_lblc_scheduler); |
627 | if (ret) | |
61b1ab45 | 628 | unregister_pernet_subsys(&ip_vs_lblc_ops); |
a014bc8f | 629 | return ret; |
1da177e4 LT |
630 | } |
631 | ||
1da177e4 LT |
632 | static void __exit ip_vs_lblc_cleanup(void) |
633 | { | |
1da177e4 | 634 | unregister_ip_vs_scheduler(&ip_vs_lblc_scheduler); |
61b1ab45 | 635 | unregister_pernet_subsys(&ip_vs_lblc_ops); |
ceec4c38 | 636 | synchronize_rcu(); |
1da177e4 LT |
637 | } |
638 | ||
639 | ||
640 | module_init(ip_vs_lblc_init); | |
641 | module_exit(ip_vs_lblc_cleanup); | |
642 | MODULE_LICENSE("GPL"); |