inetpeer: Abstract address comparisons. (02663045) · Commits · 戴 / test

net/ipv4/inetpeer.c

+27 −8

Original line number	Diff line number	Diff line
		@@ -152,6 +152,22 @@ static void unlink_from_unused(struct inet_peer *p)
		}
		}

		static int addr_compare(const inet_peer_address_t *a,
		const inet_peer_address_t *b)
		{
		int i, n = (a->family == AF_INET ? 1 : 4);

		for (i = 0; i < n; i++) {
		if (a->a6[i] == b->a6[i])
		continue;
		if (a->a6[i] < b->a6[i])
		return -1;
		return 1;
		}

		return 0;
		}

		/*
		* Called with local BH disabled and the pool lock held.
		*/
		@@ -165,9 +181,10 @@ static void unlink_from_unused(struct inet_peer *p)
		for (u = rcu_dereference_protected(_base->root, \
		lockdep_is_held(&_base->lock)); \
		u != peer_avl_empty; ) { \
		if (_daddr == u->daddr.a4) \
		int cmp = addr_compare(_daddr, &u->daddr); \
		if (cmp == 0) \
		break; \
		if ((__force __u32)_daddr < (__force __u32)u->daddr.a4) \
		if (cmp == -1) \
		v = &u->avl_left; \
		else \
		v = &u->avl_right; \
		@@ -185,13 +202,15 @@ static void unlink_from_unused(struct inet_peer *p)
		* But every pointer we follow is guaranteed to be valid thanks to RCU.
		* We exit from this function if number of links exceeds PEER_MAXDEPTH
		*/
		static struct inet_peer lookup_rcu_bh(__be32 daddr, struct inet_peer_base base)
		static struct inet_peer lookup_rcu_bh(const inet_peer_address_t daddr,
		struct inet_peer_base *base)
		{
		struct inet_peer *u = rcu_dereference_bh(base->root);
		int count = 0;

		while (u != peer_avl_empty) {
		if (daddr == u->daddr.a4) {
		int cmp = addr_compare(daddr, &u->daddr);
		if (cmp == 0) {
		/* Before taking a reference, check if this entry was
		* deleted, unlink_from_pool() sets refcnt=-1 to make
		* distinction between an unused entry (refcnt=0) and
		@@ -201,7 +220,7 @@ static struct inet_peer lookup_rcu_bh(__be32 daddr, struct inet_peer_base base
		u = NULL;
		return u;
		}
		if ((__force __u32)daddr < (__force __u32)u->daddr.a4)
		if (cmp == -1)
		u = rcu_dereference_bh(u->avl_left);
		else
		u = rcu_dereference_bh(u->avl_right);
		@@ -354,7 +373,7 @@ static void unlink_from_pool(struct inet_peer p, struct inet_peer_base base)
		if (atomic_cmpxchg(&p->refcnt, 1, -1) == 1) {
		struct inet_peer __rcu **stack[PEER_MAXDEPTH];
		struct inet_peer __rcu *stackptr, *delp;
		if (lookup(p->daddr.a4, stack, base) != p)
		if (lookup(&p->daddr, stack, base) != p)
		BUG();
		delp = stackptr - 1; /* delp[0] == p /
		if (p->avl_left == peer_avl_empty_rcu) {
		@@ -454,7 +473,7 @@ struct inet_peer inet_getpeer(inet_peer_address_t daddr, int create)
		* Because of a concurrent writer, we might not find an existing entry.
		*/
		rcu_read_lock_bh();
		p = lookup_rcu_bh(daddr->a4, base);
		p = lookup_rcu_bh(daddr, base);
		rcu_read_unlock_bh();

		if (p) {
		@@ -469,7 +488,7 @@ struct inet_peer inet_getpeer(inet_peer_address_t daddr, int create)
		* At least, nodes should be hot in our cache.
		*/
		spin_lock_bh(&base->lock);
		p = lookup(daddr->a4, stack, base);
		p = lookup(daddr, stack, base);
		if (p != peer_avl_empty) {
		atomic_inc(&p->refcnt);
		spin_unlock_bh(&base->lock);

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