diff options
| -rw-r--r-- | include/net/route.h | 1 | ||||
| -rw-r--r-- | net/ipv4/fib_frontend.c | 5 | ||||
| -rw-r--r-- | net/ipv4/route.c | 940 |
3 files changed, 13 insertions, 933 deletions
diff --git a/include/net/route.h b/include/net/route.h index ace3cb4..5dcfeb6 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -109,7 +109,6 @@ extern struct ip_rt_acct __percpu *ip_rt_acct; struct in_device; extern int ip_rt_init(void); extern void rt_cache_flush(struct net *net, int how); -extern void rt_cache_flush_batch(struct net *net); extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, struct sock *sk); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index b832036..f277cf0 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1072,11 +1072,6 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo rt_cache_flush(dev_net(dev), 0); break; case NETDEV_UNREGISTER_BATCH: - /* The batch unregister is only called on the first - * device in the list of devices being unregistered. - * Therefore we should not pass dev_net(dev) in here. - */ - rt_cache_flush_batch(NULL); break; } return NOTIFY_DONE; diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d547f6f..6d6146d 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -133,10 +133,6 @@ static int ip_rt_gc_elasticity __read_mostly = 8; static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; static int ip_rt_min_advmss __read_mostly = 256; -static int rt_chain_length_max __read_mostly = 20; - -static struct delayed_work expires_work; -static unsigned long expires_ljiffies; /* * Interface to generic destination cache. @@ -152,7 +148,6 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu); static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb); -static int rt_garbage_collect(struct dst_ops *ops); static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) @@ -172,7 +167,6 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, static struct dst_ops ipv4_dst_ops = { .family = AF_INET, .protocol = cpu_to_be16(ETH_P_IP), - .gc = rt_garbage_collect, .check = ipv4_dst_check, .default_advmss = ipv4_default_advmss, .mtu = ipv4_mtu, @@ -209,184 +203,30 @@ const __u8 ip_tos2prio[16] = { }; EXPORT_SYMBOL(ip_tos2prio); -/* - * Route cache. - */ - -/* The locking scheme is rather straight forward: - * - * 1) Read-Copy Update protects the buckets of the central route hash. - * 2) Only writers remove entries, and they hold the lock - * as they look at rtable reference counts. - * 3) Only readers acquire references to rtable entries, - * they do so with atomic increments and with the - * lock held. - */ - -struct rt_hash_bucket { - struct rtable __rcu *chain; -}; - -#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ - defined(CONFIG_PROVE_LOCKING) -/* - * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks - * The size of this table is a power of two and depends on the number of CPUS. - * (on lockdep we have a quite big spinlock_t, so keep the size down there) - */ -#ifdef CONFIG_LOCKDEP -# define RT_HASH_LOCK_SZ 256 -#else -# if NR_CPUS >= 32 -# define RT_HASH_LOCK_SZ 4096 -# elif NR_CPUS >= 16 -# define RT_HASH_LOCK_SZ 2048 -# elif NR_CPUS >= 8 -# define RT_HASH_LOCK_SZ 1024 -# elif NR_CPUS >= 4 -# define RT_HASH_LOCK_SZ 512 -# else -# define RT_HASH_LOCK_SZ 256 -# endif -#endif - -static spinlock_t *rt_hash_locks; -# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] - -static __init void rt_hash_lock_init(void) -{ - int i; - - rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, - GFP_KERNEL); - if (!rt_hash_locks) - panic("IP: failed to allocate rt_hash_locks\n"); - - for (i = 0; i < RT_HASH_LOCK_SZ; i++) - spin_lock_init(&rt_hash_locks[i]); -} -#else -# define rt_hash_lock_addr(slot) NULL - -static inline void rt_hash_lock_init(void) -{ -} -#endif - -static struct rt_hash_bucket *rt_hash_table __read_mostly; -static unsigned int rt_hash_mask __read_mostly; -static unsigned int rt_hash_log __read_mostly; - static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) -static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, - int genid) -{ - return jhash_3words((__force u32)daddr, (__force u32)saddr, - idx, genid) - & rt_hash_mask; -} - static inline int rt_genid(struct net *net) { return atomic_read(&net->ipv4.rt_genid); } #ifdef CONFIG_PROC_FS -struct rt_cache_iter_state { - struct seq_net_private p; - int bucket; - int genid; -}; - -static struct rtable *rt_cache_get_first(struct seq_file *seq) -{ - struct rt_cache_iter_state *st = seq->private; - struct rtable *r = NULL; - - for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { - if (!rcu_access_pointer(rt_hash_table[st->bucket].chain)) - continue; - rcu_read_lock_bh(); - r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); - while (r) { - if (dev_net(r->dst.dev) == seq_file_net(seq) && - r->rt_genid == st->genid) - return r; - r = rcu_dereference_bh(r->dst.rt_next); - } - rcu_read_unlock_bh(); - } - return r; -} - -static struct rtable *__rt_cache_get_next(struct seq_file *seq, - struct rtable *r) -{ - struct rt_cache_iter_state *st = seq->private; - - r = rcu_dereference_bh(r->dst.rt_next); - while (!r) { - rcu_read_unlock_bh(); - do { - if (--st->bucket < 0) - return NULL; - } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain)); - rcu_read_lock_bh(); - r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); - } - return r; -} - -static struct rtable *rt_cache_get_next(struct seq_file *seq, - struct rtable *r) -{ - struct rt_cache_iter_state *st = seq->private; - while ((r = __rt_cache_get_next(seq, r)) != NULL) { - if (dev_net(r->dst.dev) != seq_file_net(seq)) - continue; - if (r->rt_genid == st->genid) - break; - } - return r; -} - -static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) -{ - struct rtable *r = rt_cache_get_first(seq); - - if (r) - while (pos && (r = rt_cache_get_next(seq, r))) - --pos; - return pos ? NULL : r; -} - static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) { - struct rt_cache_iter_state *st = seq->private; if (*pos) - return rt_cache_get_idx(seq, *pos - 1); - st->genid = rt_genid(seq_file_net(seq)); + return NULL; return SEQ_START_TOKEN; } static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) { - struct rtable *r; - - if (v == SEQ_START_TOKEN) - r = rt_cache_get_first(seq); - else - r = rt_cache_get_next(seq, v); ++*pos; - return r; + return NULL; } static void rt_cache_seq_stop(struct seq_file *seq, void *v) { - if (v && v != SEQ_START_TOKEN) - rcu_read_unlock_bh(); } static int rt_cache_seq_show(struct seq_file *seq, void *v) @@ -396,24 +236,6 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" "HHUptod\tSpecDst"); - else { - struct rtable *r = v; - int len; - - seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" - "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", - r->dst.dev ? r->dst.dev->name : "*", - (__force u32)r->rt_dst, - (__force u32)r->rt_gateway, - r->rt_flags, atomic_read(&r->dst.__refcnt), - r->dst.__use, 0, (__force u32)r->rt_src, - dst_metric_advmss(&r->dst) + 40, - dst_metric(&r->dst, RTAX_WINDOW), 0, - r->rt_key_tos, - -1, 0, 0, &len); - - seq_printf(seq, "%*s\n", 127 - len, ""); - } return 0; } @@ -426,8 +248,7 @@ static const struct seq_operations rt_cache_seq_ops = { static int rt_cache_seq_open(struct inode *inode, struct file *file) { - return seq_open_net(inode, file, &rt_cache_seq_ops, - sizeof(struct rt_cache_iter_state)); + return seq_open(file, &rt_cache_seq_ops); } static const struct file_operations rt_cache_seq_fops = { @@ -435,7 +256,7 @@ static const struct file_operations rt_cache_seq_fops = { .open = rt_cache_seq_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_net, + .release = seq_release, }; @@ -625,263 +446,12 @@ static inline int ip_rt_proc_init(void) } #endif /* CONFIG_PROC_FS */ -static inline void rt_free(struct rtable *rt) -{ - call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); -} - -static inline void rt_drop(struct rtable *rt) -{ - ip_rt_put(rt); - call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); -} - -static inline int rt_fast_clean(struct rtable *rth) -{ - /* Kill broadcast/multicast entries very aggresively, if they - collide in hash table with more useful entries */ - return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && - rt_is_input_route(rth) && rth->dst.rt_next; -} - -static inline int rt_valuable(struct rtable *rth) -{ - return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || - rth->dst.expires; -} - -static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) -{ - unsigned long age; - int ret = 0; - - if (atomic_read(&rth->dst.__refcnt)) - goto out; - - age = jiffies - rth->dst.lastuse; - if ((age <= tmo1 && !rt_fast_clean(rth)) || - (age <= tmo2 && rt_valuable(rth))) - goto out; - ret = 1; -out: return ret; -} - -/* Bits of score are: - * 31: very valuable - * 30: not quite useless - * 29..0: usage counter - */ -static inline u32 rt_score(struct rtable *rt) -{ - u32 score = jiffies - rt->dst.lastuse; - - score = ~score & ~(3<<30); - - if (rt_valuable(rt)) - score |= (1<<31); - - if (rt_is_output_route(rt) || - !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) - score |= (1<<30); - - return score; -} - -static inline bool rt_caching(const struct net *net) -{ - return net->ipv4.current_rt_cache_rebuild_count <= - net->ipv4.sysctl_rt_cache_rebuild_count; -} - -static inline bool compare_hash_inputs(const struct rtable *rt1, - const struct rtable *rt2) -{ - return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | - ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | - (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0); -} - -static inline int compare_keys(struct rtable *rt1, struct rtable *rt2) -{ - return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | - ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | - (rt1->rt_mark ^ rt2->rt_mark) | - (rt1->rt_key_tos ^ rt2->rt_key_tos) | - (rt1->rt_route_iif ^ rt2->rt_route_iif) | - (rt1->rt_oif ^ rt2->rt_oif)) == 0; -} - -static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) -{ - return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev)); -} - static inline int rt_is_expired(struct rtable *rth) { return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); } /* - * Perform a full scan of hash table and free all entries. - * Can be called by a softirq or a process. - * In the later case, we want to be reschedule if necessary - */ -static void rt_do_flush(struct net *net, int process_context) -{ - unsigned int i; - struct rtable *rth, *next; - - for (i = 0; i <= rt_hash_mask; i++) { - struct rtable __rcu **pprev; - struct rtable *list; - - if (process_context && need_resched()) - cond_resched(); - rth = rcu_access_pointer(rt_hash_table[i].chain); - if (!rth) - continue; - - spin_lock_bh(rt_hash_lock_addr(i)); - - list = NULL; - pprev = &rt_hash_table[i].chain; - rth = rcu_dereference_protected(*pprev, - lockdep_is_held(rt_hash_lock_addr(i))); - - while (rth) { - next = rcu_dereference_protected(rth->dst.rt_next, - lockdep_is_held(rt_hash_lock_addr(i))); - - if (!net || - net_eq(dev_net(rth->dst.dev), net)) { - rcu_assign_pointer(*pprev, next); - rcu_assign_pointer(rth->dst.rt_next, list); - list = rth; - } else { - pprev = &rth->dst.rt_next; - } - rth = next; - } - - spin_unlock_bh(rt_hash_lock_addr(i)); - - for (; list; list = next) { - next = rcu_dereference_protected(list->dst.rt_next, 1); - rt_free(list); - } - } -} - -/* - * While freeing expired entries, we compute average chain length - * and standard deviation, using fixed-point arithmetic. - * This to have an estimation of rt_chain_length_max - * rt_chain_length_max = max(elasticity, AVG + 4*SD) - * We use 3 bits for frational part, and 29 (or 61) for magnitude. - */ - -#define FRACT_BITS 3 -#define ONE (1UL << FRACT_BITS) - -/* - * Given a hash chain and an item in this hash chain, - * find if a previous entry has the same hash_inputs - * (but differs on tos, mark or oif) - * Returns 0 if an alias is found. - * Returns ONE if rth has no alias before itself. - */ -static int has_noalias(const struct rtable *head, const struct rtable *rth) -{ - const struct rtable *aux = head; - - while (aux != rth) { - if (compare_hash_inputs(aux, rth)) - return 0; - aux = rcu_dereference_protected(aux->dst.rt_next, 1); - } - return ONE; -} - -static void rt_check_expire(void) -{ - static unsigned int rover; - unsigned int i = rover, goal; - struct rtable *rth; - struct rtable __rcu **rthp; - unsigned long samples = 0; - unsigned long sum = 0, sum2 = 0; - unsigned long delta; - u64 mult; - - delta = jiffies - expires_ljiffies; - expires_ljiffies = jiffies; - mult = ((u64)delta) << rt_hash_log; - if (ip_rt_gc_timeout > 1) - do_div(mult, ip_rt_gc_timeout); - goal = (unsigned int)mult; - if (goal > rt_hash_mask) - goal = rt_hash_mask + 1; - for (; goal > 0; goal--) { - unsigned long tmo = ip_rt_gc_timeout; - unsigned long length; - - i = (i + 1) & rt_hash_mask; - rthp = &rt_hash_table[i].chain; - - if (need_resched()) - cond_resched(); - - samples++; - - if (rcu_dereference_raw(*rthp) == NULL) - continue; - length = 0; - spin_lock_bh(rt_hash_lock_addr(i)); - while ((rth = rcu_dereference_protected(*rthp, - lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) { - prefetch(rth->dst.rt_next); - if (rt_is_expired(rth) || - rt_may_expire(rth, tmo, ip_rt_gc_timeout)) { - *rthp = rth->dst.rt_next; - rt_free(rth); - continue; - } - - /* We only count entries on a chain with equal - * hash inputs once so that entries for - * different QOS levels, and other non-hash - * input attributes don't unfairly skew the - * length computation - */ - tmo >>= 1; - rthp = &rth->dst.rt_next; - length += has_noalias(rt_hash_table[i].chain, rth); - } - spin_unlock_bh(rt_hash_lock_addr(i)); - sum += length; - sum2 += length*length; - } - if (samples) { - unsigned long avg = sum / samples; - unsigned long sd = int_sqrt(sum2 / samples - avg*avg); - rt_chain_length_max = max_t(unsigned long, - ip_rt_gc_elasticity, - (avg + 4*sd) >> FRACT_BITS); - } - rover = i; -} - -/* - * rt_worker_func() is run in process context. - * we call rt_check_expire() to scan part of the hash table - */ -static void rt_worker_func(struct work_struct *work) -{ - rt_check_expire(); - schedule_delayed_work(&expires_work, ip_rt_gc_interval); -} - -/* * Perturbation of rt_genid by a small quantity [1..256] * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() * many times (2^24) without giving recent rt_genid. @@ -902,167 +472,6 @@ static void rt_cache_invalidate(struct net *net) void rt_cache_flush(struct net *net, int delay) { rt_cache_invalidate(net); - if (delay >= 0) - rt_do_flush(net, !in_softirq()); -} - -/* Flush previous cache invalidated entries from the cache */ -void rt_cache_flush_batch(struct net *net) -{ - rt_do_flush(net, !in_softirq()); -} - -static void rt_emergency_hash_rebuild(struct net *net) -{ - net_warn_ratelimited("Route hash chain too long!\n"); - rt_cache_invalidate(net); -} - -/* - Short description of GC goals. - - We want to build algorithm, which will keep routing cache - at some equilibrium point, when number of aged off entries - is kept approximately equal to newly generated ones. - - Current expiration strength is variable "expire". - We try to adjust it dynamically, so that if networking - is idle expires is large enough to keep enough of warm entries, - and when load increases it reduces to limit cache size. - */ - -static int rt_garbage_collect(struct dst_ops *ops) -{ - static unsigned long expire = RT_GC_TIMEOUT; - static unsigned long last_gc; - static int rover; - static int equilibrium; - struct rtable *rth; - struct rtable __rcu **rthp; - unsigned long now = jiffies; - int goal; - int entries = dst_entries_get_fast(&ipv4_dst_ops); - - /* - * Garbage collection is pretty expensive, - * do not make it too frequently. - */ - - RT_CACHE_STAT_INC(gc_total); - - if (now - last_gc < ip_rt_gc_min_interval && - entries < ip_rt_max_size) { - RT_CACHE_STAT_INC(gc_ignored); - goto out; - } - - entries = dst_entries_get_slow(&ipv4_dst_ops); - /* Calculate number of entries, which we want to expire now. */ - goal = entries - (ip_rt_gc_elasticity << rt_hash_log); - if (goal <= 0) { - if (equilibrium < ipv4_dst_ops.gc_thresh) - equilibrium = ipv4_dst_ops.gc_thresh; - goal = entries - equilibrium; - if (goal > 0) { - equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); - goal = entries - equilibrium; - } - } else { - /* We are in dangerous area. Try to reduce cache really - * aggressively. - */ - goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); - equilibrium = entries - goal; - } - - if (now - last_gc >= ip_rt_gc_min_interval) - last_gc = now; - - if (goal <= 0) { - equilibrium += goal; - goto work_done; - } - - do { - int i, k; - - for (i = rt_hash_mask, k = rover; i >= 0; i--) { - unsigned long tmo = expire; - - k = (k + 1) & rt_hash_mask; - rthp = &rt_hash_table[k].chain; - spin_lock_bh(rt_hash_lock_addr(k)); - while ((rth = rcu_dereference_protected(*rthp, - lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) { - if (!rt_is_expired(rth) && - !rt_may_expire(rth, tmo, expire)) { - tmo >>= 1; - rthp = &rth->dst.rt_next; - continue; - } - *rthp = rth->dst.rt_next; - rt_free(rth); - goal--; - } - spin_unlock_bh(rt_hash_lock_addr(k)); - if (goal <= 0) - break; - } - rover = k; - - if (goal <= 0) - goto work_done; - - /* Goal is not achieved. We stop process if: - - - if expire reduced to zero. Otherwise, expire is halfed. - - if table is not full. - - if we are called from interrupt. - - jiffies check is just fallback/debug loop breaker. - We will not spin here for long time in any case. - */ - - RT_CACHE_STAT_INC(gc_goal_miss); - - if (expire == 0) - break; - - expire >>= 1; - - if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) - goto out; - } while (!in_softirq() && time_before_eq(jiffies, now)); - - if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) - goto out; - if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size) - goto out; - net_warn_ratelimited("dst cache overflow\n"); - RT_CACHE_STAT_INC(gc_dst_overflow); - return 1; - -work_done: - expire += ip_rt_gc_min_interval; - if (expire > ip_rt_gc_timeout || - dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh || - dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh) - expire = ip_rt_gc_timeout; -out: return 0; -} - -/* - * Returns number of entries in a hash chain that have different hash_inputs - */ -static int slow_chain_length(const struct rtable *head) -{ - int length = 0; - const struct rtable *rth = head; - - while (rth) { - length += has_noalias(head, rth); - rth = rcu_dereference_protected(rth->dst.rt_next, 1); - } - return length >> FRACT_BITS; } static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, @@ -1086,139 +495,6 @@ static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, return neigh_create(&arp_tbl, pkey, dev); } -static struct rtable *rt_intern_hash(unsigned int hash, struct rtable *rt, - struct sk_buff *skb, int ifindex) -{ - struct rtable *rth, *cand; - struct rtable __rcu **rthp, **candp; - unsigned long now; - u32 min_score; - int chain_length; - -restart: - chain_length = 0; - min_score = ~(u32)0; - cand = NULL; - candp = NULL; - now = jiffies; - - if (!rt_caching(dev_net(rt->dst.dev)) || (rt->dst.flags & DST_NOCACHE)) { - /* - * If we're not caching, just tell the caller we - * were successful and don't touch the route. The - * caller hold the sole reference to the cache entry, and - * it will be released when the caller is done with it. - * If we drop it here, the callers have no way to resolve routes - * when we're not caching. Instead, just point *rp at rt, so - * the caller gets a single use out of the route - * Note that we do rt_free on this new route entry, so that - * once its refcount hits zero, we are still able to reap it - * (Thanks Alexey) - * Note: To avoid expensive rcu stuff for this uncached dst, - * we set DST_NOCACHE so that dst_release() can free dst without - * waiting a grace period. - */ - - rt->dst.flags |= DST_NOCACHE; - goto skip_hashing; - } - - rthp = &rt_hash_table[hash].chain; - - spin_lock_bh(rt_hash_lock_addr(hash)); - while ((rth = rcu_dereference_protected(*rthp, - lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { - if (rt_is_expired(rth)) { - *rthp = rth->dst.rt_next; - rt_free(rth); - continue; - } - if (compare_keys(rth, rt) && compare_netns(rth, rt)) { - /* Put it first */ - *rthp = rth->dst.rt_next; - /* - * Since lookup is lockfree, the deletion - * must be visible to another weakly ordered CPU before - * the insertion at the start of the hash chain. - */ - rcu_assign_pointer(rth->dst.rt_next, - rt_hash_table[hash].chain); - /* - * Since lookup is lockfree, the update writes - * must be ordered for consistency on SMP. - */ - rcu_assign_pointer(rt_hash_table[hash].chain, rth); - - dst_use(&rth->dst, now); - spin_unlock_bh(rt_hash_lock_addr(hash)); - - rt_drop(rt); - if (skb) - skb_dst_set(skb, &rth->dst); - return rth; - } - - if (!atomic_read(&rth->dst.__refcnt)) { - u32 score = rt_score(rth); - - if (score <= min_score) { - cand = rth; - candp = rthp; - min_score = score; - } - } - - chain_length++; - - rthp = &rth->dst.rt_next; - } - - if (cand) { - /* ip_rt_gc_elasticity used to be average length of chain - * length, when exceeded gc becomes really aggressive. - * - * The second limit is less certain. At the moment it allows - * only 2 entries per bucket. We will see. - */ - if (chain_length > ip_rt_gc_elasticity) { - *candp = cand->dst.rt_next; - rt_free(cand); - } - } else { - if (chain_length > rt_chain_length_max && - slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { - struct net *net = dev_net(rt->dst.dev); - int num = ++net->ipv4.current_rt_cache_rebuild_count; - if (!rt_caching(net)) { - pr_warn("%s: %d rebuilds is over limit, route caching disabled\n", - rt->dst.dev->name, num); - } - rt_emergency_hash_rebuild(net); - spin_unlock_bh(rt_hash_lock_addr(hash)); - - hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, - ifindex, rt_genid(net)); - goto restart; - } - } - - rt->dst.rt_next = rt_hash_table[hash].chain; - - /* - * Since lookup is lockfree, we must make sure - * previous writes to rt are committed to memory - * before making rt visible to other CPUS. - */ - rcu_assign_pointer(rt_hash_table[hash].chain, rt); - - spin_unlock_bh(rt_hash_lock_addr(hash)); - -skip_hashing: - if (skb) - skb_dst_set(skb, &rt->dst); - return rt; -} - /* * Peer allocation may fail only in serious out-of-memory conditions. However * we still can generate some output. @@ -1255,26 +531,6 @@ void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) } EXPORT_SYMBOL(__ip_select_ident); -static void rt_del(unsigned int hash, struct rtable *rt) -{ - struct rtable __rcu **rthp; - struct rtable *aux; - - rthp = &rt_hash_table[hash].chain; - spin_lock_bh(rt_hash_lock_addr(hash)); - ip_rt_put(rt); - while ((aux = rcu_dereference_protected(*rthp, - lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { - if (aux == rt || rt_is_expired(aux)) { - *rthp = aux->dst.rt_next; - rt_free(aux); - continue; - } - rthp = &aux->dst.rt_next; - } - spin_unlock_bh(rt_hash_lock_addr(hash)); -} - static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, const struct iphdr *iph, int oif, u8 tos, @@ -1518,10 +774,7 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) ret = NULL; } else if ((rt->rt_flags & RTCF_REDIRECTED) || rt->dst.expires) { - unsigned int hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, - rt->rt_oif, - rt_genid(dev_net(dst->dev))); - rt_del(hash, rt); + ip_rt_put(rt); ret = NULL; } } @@ -1969,7 +1222,7 @@ static struct rtable *rt_dst_alloc(struct net_device *dev, bool nopolicy, bool noxfrm) { return dst_alloc(&ipv4_dst_ops, dev, 1, -1, - DST_HOST | + DST_HOST | DST_NOCACHE | (nopolicy ? DST_NOPOLICY : 0) | (noxfrm ? DST_NOXFRM : 0)); } @@ -1978,7 +1231,6 @@ static struct rtable *rt_dst_alloc(struct net_device *dev, static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, u8 tos, struct net_device *dev, int our) { - unsigned int hash; struct rtable *rth; struct in_device *in_dev = __in_dev_get_rcu(dev); u32 itag = 0; @@ -2042,9 +1294,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, #endif RT_CACHE_STAT_INC(in_slow_mc); - hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); - rth = rt_intern_hash(hash, rth, skb, dev->ifindex); - return IS_ERR(rth) ? PTR_ERR(rth) : 0; + skb_dst_set(skb, &rth->dst); + return 0; e_nobufs: return -ENOBUFS; @@ -2176,7 +1427,6 @@ static int ip_mkroute_input(struct sk_buff *skb, { struct rtable *rth = NULL; int err; - unsigned int hash; #ifdef CONFIG_IP_ROUTE_MULTIPATH if (res->fi && res->fi->fib_nhs > 1) @@ -2188,12 +1438,7 @@ static int ip_mkroute_input(struct sk_buff *skb, if (err) return err; - /* put it into the cache */ - hash = rt_hash(daddr, saddr, fl4->flowi4_iif, - rt_genid(dev_net(rth->dst.dev))); - rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); - if (IS_ERR(rth)) - return PTR_ERR(rth); + skb_dst_set(skb, &rth->dst); return 0; } @@ -2217,7 +1462,6 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, unsigned int flags = 0; u32 itag = 0; struct rtable *rth; - unsigned int hash; int err = -EINVAL; struct net *net = dev_net(dev); @@ -2339,11 +1583,8 @@ local_input: rth->dst.error= -err; rth->rt_flags &= ~RTCF_LOCAL; } - hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); - rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); + skb_dst_set(skb, &rth->dst); err = 0; - if (IS_ERR(rth)) - err = PTR_ERR(rth); goto out; no_route: @@ -2382,46 +1623,10 @@ martian_source_keep_err: int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, u8 tos, struct net_device *dev, bool noref) { - struct rtable *rth; - unsigned int hash; - int iif = dev->ifindex; - struct net *net; int res; - net = dev_net(dev); - rcu_read_lock(); - if (!rt_caching(net)) - goto skip_cache; - - tos &= IPTOS_RT_MASK; - hash = rt_hash(daddr, saddr, iif, rt_genid(net)); - - for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; - rth = rcu_dereference(rth->dst.rt_next)) { - if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | - ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | - (rth->rt_route_iif ^ iif) | - (rth->rt_key_tos ^ tos)) == 0 && - rth->rt_mark == skb->mark && - net_eq(dev_net(rth->dst.dev), net) && - !rt_is_expired(rth)) { - if (noref) { - dst_use_noref(&rth->dst, jiffies); - skb_dst_set_noref(skb, &rth->dst); - } else { - dst_use(&rth->dst, jiffies); - skb_dst_set(skb, &rth->dst); - } - RT_CACHE_STAT_INC(in_hit); - rcu_read_unlock(); - return 0; - } - RT_CACHE_STAT_INC(in_hlist_search); - } - -skip_cache: /* Multicast recognition logic is moved from route cache to here. The problem was that too many Ethernet cards have broken/missing hardware multicast filters :-( As result the host on multicasting @@ -2563,10 +1768,9 @@ static struct rtable *__mkroute_output(const struct fib_result *res, /* * Major route resolver routine. - * called with rcu_read_lock(); */ -static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) +struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) { struct net_device *dev_out = NULL; __u8 tos = RT_FL_TOS(fl4); @@ -2746,57 +1950,11 @@ static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) make_route: rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif, tos, dev_out, flags); - if (!IS_ERR(rth)) { - unsigned int hash; - - hash = rt_hash(orig_daddr, orig_saddr, orig_oif, - rt_genid(dev_net(dev_out))); - rth = rt_intern_hash(hash, rth, NULL, orig_oif); - } out: rcu_read_unlock(); return rth; } - -struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) -{ - struct rtable *rth; - unsigned int hash; - - if (!rt_caching(net)) - goto slow_output; - - hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); - - rcu_read_lock_bh(); - for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; - rth = rcu_dereference_bh(rth->dst.rt_next)) { - if (rth->rt_key_dst == flp4->daddr && - rth->rt_key_src == flp4->saddr && - rt_is_output_route(rth) && - rth->rt_oif == flp4->flowi4_oif && - rth->rt_mark == flp4->flowi4_mark && - !((rth->rt_key_tos ^ flp4->flowi4_tos) & - (IPTOS_RT_MASK | RTO_ONLINK)) && - net_eq(dev_net(rth->dst.dev), net) && - !rt_is_expired(rth)) { - dst_use(&rth->dst, jiffies); - RT_CACHE_STAT_INC(out_hit); - rcu_read_unlock_bh(); - if (!flp4->saddr) - flp4->saddr = rth->rt_src; - if (!flp4->daddr) - flp4->daddr = rth->rt_dst; - return rth; - } - RT_CACHE_STAT_INC(out_hlist_search); - } - rcu_read_unlock_bh(); - -slow_output: - return ip_route_output_slow(net, flp4); -} EXPORT_SYMBOL_GPL(__ip_route_output_key); static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) @@ -3106,43 +2264,6 @@ errout_free: int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) { - struct rtable *rt; - int h, s_h; - int idx, s_idx; - struct net *net; - - net = sock_net(skb->sk); - - s_h = cb->args[0]; - if (s_h < 0) - s_h = 0; - s_idx = idx = cb->args[1]; - for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { - if (!rt_hash_table[h].chain) - continue; - rcu_read_lock_bh(); - for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; - rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { - if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) - continue; - if (rt_is_expired(rt)) - continue; - skb_dst_set_noref(skb, &rt->dst); - if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, - cb->nlh->nlmsg_seq, RTM_NEWROUTE, - 1, NLM_F_MULTI) <= 0) { - skb_dst_drop(skb); - rcu_read_unlock_bh(); - goto done; - } - skb_dst_drop(skb); - } - rcu_read_unlock_bh(); - } - -done: - cb->args[0] = h; - cb->args[1] = idx; return skb->len; } @@ -3376,22 +2497,6 @@ static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; #endif /* CONFIG_IP_ROUTE_CLASSID */ -static __initdata unsigned long rhash_entries; -static int __init set_rhash_entries(char *str) -{ - ssize_t ret; - - if (!str) - return 0; - - ret = kstrtoul(str, 0, &rhash_entries); - if (ret) - return 0; - - return 1; -} -__setup("rhash_entries=", set_rhash_entries); - int __init ip_rt_init(void) { int rc = 0; @@ -3414,31 +2519,12 @@ int __init ip_rt_init(void) if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); - rt_hash_table = (struct rt_hash_bucket *) - alloc_large_system_hash("IP route cache", - sizeof(struct rt_hash_bucket), - rhash_entries, - (totalram_pages >= 128 * 1024) ? - 15 : 17, - 0, - &rt_hash_log, - &rt_hash_mask, - 0, - rhash_entries ? 0 : 512 * 1024); - memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); - rt_hash_lock_init(); - - ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); - ip_rt_max_size = (rt_hash_mask + 1) * 16; + ipv4_dst_ops.gc_thresh = ~0; + ip_rt_max_size = INT_MAX; devinet_init(); ip_fib_init(); - INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func); - expires_ljiffies = jiffies; - schedule_delayed_work(&expires_work, - net_random() % ip_rt_gc_interval + ip_rt_gc_interval); - if (ip_rt_proc_init()) pr_err("Unable to create route proc files\n"); #ifdef CONFIG_XFRM |
