diff options
| -rw-r--r-- | net/ipv4/ipvs/ip_vs_lblcr.c | 229 |
1 files changed, 114 insertions, 115 deletions
diff --git a/net/ipv4/ipvs/ip_vs_lblcr.c b/net/ipv4/ipvs/ip_vs_lblcr.c index f1c84503689..375a1ffb6b6 100644 --- a/net/ipv4/ipvs/ip_vs_lblcr.c +++ b/net/ipv4/ipvs/ip_vs_lblcr.c @@ -106,7 +106,7 @@ ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) return NULL; } - e = kmalloc(sizeof(struct ip_vs_dest_list), GFP_ATOMIC); + e = kmalloc(sizeof(*e), GFP_ATOMIC); if (e == NULL) { IP_VS_ERR("ip_vs_dest_set_insert(): no memory\n"); return NULL; @@ -116,11 +116,9 @@ ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) e->dest = dest; /* link it to the list */ - write_lock(&set->lock); e->next = set->list; set->list = e; atomic_inc(&set->size); - write_unlock(&set->lock); set->lastmod = jiffies; return e; @@ -131,7 +129,6 @@ ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) { struct ip_vs_dest_list *e, **ep; - write_lock(&set->lock); for (ep=&set->list, e=*ep; e!=NULL; e=*ep) { if (e->dest == dest) { /* HIT */ @@ -144,7 +141,6 @@ ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest) } ep = &e->next; } - write_unlock(&set->lock); } static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set) @@ -174,7 +170,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) if (set == NULL) return NULL; - read_lock(&set->lock); /* select the first destination server, whose weight > 0 */ for (e=set->list; e!=NULL; e=e->next) { least = e->dest; @@ -188,7 +183,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) goto nextstage; } } - read_unlock(&set->lock); return NULL; /* find the destination with the weighted least load */ @@ -207,7 +201,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set) loh = doh; } } - read_unlock(&set->lock); IP_VS_DBG(6, "ip_vs_dest_set_min: server %d.%d.%d.%d:%d " "activeconns %d refcnt %d weight %d overhead %d\n", @@ -229,7 +222,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) if (set == NULL) return NULL; - read_lock(&set->lock); /* select the first destination server, whose weight > 0 */ for (e=set->list; e!=NULL; e=e->next) { most = e->dest; @@ -239,7 +231,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) goto nextstage; } } - read_unlock(&set->lock); return NULL; /* find the destination with the weighted most load */ @@ -256,7 +247,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set) moh = doh; } } - read_unlock(&set->lock); IP_VS_DBG(6, "ip_vs_dest_set_max: server %d.%d.%d.%d:%d " "activeconns %d refcnt %d weight %d overhead %d\n", @@ -284,7 +274,6 @@ struct ip_vs_lblcr_entry { * IPVS lblcr hash table */ struct ip_vs_lblcr_table { - rwlock_t lock; /* lock for this table */ struct list_head bucket[IP_VS_LBLCR_TAB_SIZE]; /* hash bucket */ atomic_t entries; /* number of entries */ int max_size; /* maximum size of entries */ @@ -311,32 +300,6 @@ static ctl_table vs_vars_table[] = { static struct ctl_table_header * sysctl_header; -/* - * new/free a ip_vs_lblcr_entry, which is a mapping of a destination - * IP address to a server. - */ -static inline struct ip_vs_lblcr_entry *ip_vs_lblcr_new(__be32 daddr) -{ - struct ip_vs_lblcr_entry *en; - - en = kmalloc(sizeof(struct ip_vs_lblcr_entry), GFP_ATOMIC); - if (en == NULL) { - IP_VS_ERR("ip_vs_lblcr_new(): no memory\n"); - return NULL; - } - - INIT_LIST_HEAD(&en->list); - en->addr = daddr; - - /* initilize its dest set */ - atomic_set(&(en->set.size), 0); - en->set.list = NULL; - rwlock_init(&en->set.lock); - - return en; -} - - static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en) { list_del(&en->list); @@ -358,55 +321,68 @@ static inline unsigned ip_vs_lblcr_hashkey(__be32 addr) * Hash an entry in the ip_vs_lblcr_table. * returns bool success. */ -static int +static void ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en) { - unsigned hash; - - if (!list_empty(&en->list)) { - IP_VS_ERR("ip_vs_lblcr_hash(): request for already hashed, " - "called from %p\n", __builtin_return_address(0)); - return 0; - } + unsigned hash = ip_vs_lblcr_hashkey(en->addr); - /* - * Hash by destination IP address - */ - hash = ip_vs_lblcr_hashkey(en->addr); - - write_lock(&tbl->lock); list_add(&en->list, &tbl->bucket[hash]); atomic_inc(&tbl->entries); - write_unlock(&tbl->lock); - - return 1; } /* - * Get ip_vs_lblcr_entry associated with supplied parameters. + * Get ip_vs_lblcr_entry associated with supplied parameters. Called under + * read lock. */ static inline struct ip_vs_lblcr_entry * ip_vs_lblcr_get(struct ip_vs_lblcr_table *tbl, __be32 addr) { - unsigned hash; + unsigned hash = ip_vs_lblcr_hashkey(addr); struct ip_vs_lblcr_entry *en; - hash = ip_vs_lblcr_hashkey(addr); + list_for_each_entry(en, &tbl->bucket[hash], list) + if (en->addr == addr) + return en; + + return NULL; +} - read_lock(&tbl->lock); - list_for_each_entry(en, &tbl->bucket[hash], list) { - if (en->addr == addr) { - /* HIT */ - read_unlock(&tbl->lock); - return en; +/* + * Create or update an ip_vs_lblcr_entry, which is a mapping of a destination + * IP address to a server. Called under write lock. + */ +static inline struct ip_vs_lblcr_entry * +ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, __be32 daddr, + struct ip_vs_dest *dest) +{ + struct ip_vs_lblcr_entry *en; + + en = ip_vs_lblcr_get(tbl, daddr); + if (!en) { + en = kmalloc(sizeof(*en), GFP_ATOMIC); + if (!en) { + IP_VS_ERR("ip_vs_lblcr_new(): no memory\n"); + return NULL; } + + en->addr = daddr; + en->lastuse = jiffies; + + /* initilize its dest set */ + atomic_set(&(en->set.size), 0); + en->set.list = NULL; + rwlock_init(&en->set.lock); + + ip_vs_lblcr_hash(tbl, en); } - read_unlock(&tbl->lock); + write_lock(&en->set.lock); + ip_vs_dest_set_insert(&en->set, dest); + write_unlock(&en->set.lock); - return NULL; + return en; } @@ -418,19 +394,18 @@ static void ip_vs_lblcr_flush(struct ip_vs_lblcr_table *tbl) int i; struct ip_vs_lblcr_entry *en, *nxt; + /* No locking required, only called during cleanup. */ for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { - write_lock(&tbl->lock); list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) { ip_vs_lblcr_free(en); - atomic_dec(&tbl->entries); } - write_unlock(&tbl->lock); } } -static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl) +static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc) { + struct ip_vs_lblcr_table *tbl = svc->sched_data; unsigned long now = jiffies; int i, j; struct ip_vs_lblcr_entry *en, *nxt; @@ -438,7 +413,7 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl) for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { j = (j + 1) & IP_VS_LBLCR_TAB_MASK; - write_lock(&tbl->lock); + write_lock(&svc->sched_lock); list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { if (time_after(en->lastuse+sysctl_ip_vs_lblcr_expiration, now)) @@ -447,7 +422,7 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl) ip_vs_lblcr_free(en); atomic_dec(&tbl->entries); } - write_unlock(&tbl->lock); + write_unlock(&svc->sched_lock); } tbl->rover = j; } @@ -466,17 +441,16 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl) */ static void ip_vs_lblcr_check_expire(unsigned long data) { - struct ip_vs_lblcr_table *tbl; + struct ip_vs_service *svc = (struct ip_vs_service *) data; + struct ip_vs_lblcr_table *tbl = svc->sched_data; unsigned long now = jiffies; int goal; int i, j; struct ip_vs_lblcr_entry *en, *nxt; - tbl = (struct ip_vs_lblcr_table *)data; - if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) { /* do full expiration check */ - ip_vs_lblcr_full_check(tbl); + ip_vs_lblcr_full_check(svc); tbl->counter = 1; goto out; } @@ -493,7 +467,7 @@ static void ip_vs_lblcr_check_expire(unsigned long data) for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) { j = (j + 1) & IP_VS_LBLCR_TAB_MASK; - write_lock(&tbl->lock); + write_lock(&svc->sched_lock); list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) { if (time_before(now, en->lastuse+ENTRY_TIMEOUT)) continue; @@ -502,7 +476,7 @@ static void ip_vs_lblcr_check_expire(unsigned long data) atomic_dec(&tbl->entries); goal--; } - write_unlock(&tbl->lock); + write_unlock(&svc->sched_lock); if (goal <= 0) break; } @@ -520,15 +494,14 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) /* * Allocate the ip_vs_lblcr_table for this service */ - tbl = kmalloc(sizeof(struct ip_vs_lblcr_table), GFP_ATOMIC); + tbl = kmalloc(sizeof(*tbl), GFP_ATOMIC); if (tbl == NULL) { IP_VS_ERR("ip_vs_lblcr_init_svc(): no memory\n"); return -ENOMEM; } svc->sched_data = tbl; IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) allocated for " - "current service\n", - sizeof(struct ip_vs_lblcr_table)); + "current service\n", sizeof(*tbl)); /* * Initialize the hash buckets @@ -536,7 +509,6 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) { INIT_LIST_HEAD(&tbl->bucket[i]); } - rwlock_init(&tbl->lock); tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16; tbl->rover = 0; tbl->counter = 1; @@ -545,9 +517,8 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc) * Hook periodic timer for garbage collection */ setup_timer(&tbl->periodic_timer, ip_vs_lblcr_check_expire, - (unsigned long)tbl); - tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL; - add_timer(&tbl->periodic_timer); + (unsigned long)svc); + mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL); return 0; } @@ -564,9 +535,9 @@ static int ip_vs_lblcr_done_svc(struct ip_vs_service *svc) ip_vs_lblcr_flush(tbl); /* release the table itself */ - kfree(svc->sched_data); + kfree(tbl); IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) released\n", - sizeof(struct ip_vs_lblcr_table)); + sizeof(*tbl)); return 0; } @@ -663,50 +634,78 @@ is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc) static struct ip_vs_dest * ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) { - struct ip_vs_dest *dest; - struct ip_vs_lblcr_table *tbl; - struct ip_vs_lblcr_entry *en; + struct ip_vs_lblcr_table *tbl = svc->sched_data; struct iphdr *iph = ip_hdr(skb); + struct ip_vs_dest *dest = NULL; + struct ip_vs_lblcr_entry *en; IP_VS_DBG(6, "ip_vs_lblcr_schedule(): Scheduling...\n"); - tbl = (struct ip_vs_lblcr_table *)svc->sched_data; + /* First look in our cache */ + read_lock(&svc->sched_lock); en = ip_vs_lblcr_get(tbl, iph->daddr); - if (en == NULL) { - dest = __ip_vs_lblcr_schedule(svc, iph); - if (dest == NULL) { - IP_VS_DBG(1, "no destination available\n"); - return NULL; - } - en = ip_vs_lblcr_new(iph->daddr); - if (en == NULL) { - return NULL; - } - ip_vs_dest_set_insert(&en->set, dest); - ip_vs_lblcr_hash(tbl, en); - } else { + if (en) { + /* We only hold a read lock, but this is atomic */ + en->lastuse = jiffies; + + /* Get the least loaded destination */ + read_lock(&en->set.lock); dest = ip_vs_dest_set_min(&en->set); - if (!dest || is_overloaded(dest, svc)) { - dest = __ip_vs_lblcr_schedule(svc, iph); - if (dest == NULL) { - IP_VS_DBG(1, "no destination available\n"); - return NULL; - } - ip_vs_dest_set_insert(&en->set, dest); - } + read_unlock(&en->set.lock); + + /* More than one destination + enough time passed by, cleanup */ if (atomic_read(&en->set.size) > 1 && - jiffies-en->set.lastmod > sysctl_ip_vs_lblcr_expiration) { + time_after(jiffies, en->set.lastmod + + sysctl_ip_vs_lblcr_expiration)) { struct ip_vs_dest *m; + + write_lock(&en->set.lock); m = ip_vs_dest_set_max(&en->set); if (m) ip_vs_dest_set_erase(&en->set, m); + write_unlock(&en->set.lock); + } + + /* If the destination is not overloaded, use it */ + if (dest && !is_overloaded(dest, svc)) { + read_unlock(&svc->sched_lock); + goto out; + } + + /* The cache entry is invalid, time to schedule */ + dest = __ip_vs_lblcr_schedule(svc, iph); + if (!dest) { + IP_VS_DBG(1, "no destination available\n"); + read_unlock(&svc->sched_lock); + return NULL; } + + /* Update our cache entry */ + write_lock(&en->set.lock); + ip_vs_dest_set_insert(&en->set, dest); + write_unlock(&en->set.lock); + } + read_unlock(&svc->sched_lock); + + if (dest) + goto out; + + /* No cache entry, time to schedule */ + dest = __ip_vs_lblcr_schedule(svc, iph); + if (!dest) { + IP_VS_DBG(1, "no destination available\n"); + return NULL; } - en->lastuse = jiffies; + /* If we fail to create a cache entry, we'll just use the valid dest */ + write_lock(&svc->sched_lock); + ip_vs_lblcr_new(tbl, iph->daddr, dest); + write_unlock(&svc->sched_lock); + +out: IP_VS_DBG(6, "LBLCR: destination IP address %u.%u.%u.%u " "--> server %u.%u.%u.%u:%d\n", - NIPQUAD(en->addr), + NIPQUAD(iph->daddr), NIPQUAD(dest->addr), ntohs(dest->port)); |