From 4f70ecca9c57731b4acbe5043eb22e4416bd2368 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 3 May 2010 10:50:14 +0000 Subject: [PATCH] net: rcu fixes Add hlist_for_each_entry_rcu_bh() and hlist_for_each_entry_continue_rcu_bh() macros, and use them in ipv6_get_ifaddr(), if6_get_first() and if6_get_next() to fix lockdeps warnings. Signed-off-by: Eric Dumazet Reviewed-by: "Paul E. McKenney" Signed-off-by: David S. Miller --- include/linux/rculist.h | 29 +++++++++++++++++++++++++++++ net/ipv6/addrconf.c | 16 ++++++++-------- 2 files changed, 37 insertions(+), 8 deletions(-) diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 004908b104d5..4ec3b38ce9c5 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -428,6 +428,23 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev, ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ pos = rcu_dereference_raw(pos->next)) +/** + * hlist_for_each_entry_rcu_bh - iterate over rcu list of given type + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_node to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as hlist_add_head_rcu() + * as long as the traversal is guarded by rcu_read_lock(). + */ +#define hlist_for_each_entry_rcu_bh(tpos, pos, head, member) \ + for (pos = rcu_dereference_bh((head)->first); \ + pos && ({ prefetch(pos->next); 1; }) && \ + ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ + pos = rcu_dereference_bh(pos->next)) + /** * hlist_for_each_entry_continue_rcu - iterate over a hlist continuing after current point * @tpos: the type * to use as a loop cursor. @@ -440,6 +457,18 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev, ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ pos = rcu_dereference(pos->next)) +/** + * hlist_for_each_entry_continue_rcu_bh - iterate over a hlist continuing after current point + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_node to use as a loop cursor. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry_continue_rcu_bh(tpos, pos, member) \ + for (pos = rcu_dereference_bh((pos)->next); \ + pos && ({ prefetch(pos->next); 1; }) && \ + ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ + pos = rcu_dereference_bh(pos->next)) + #endif /* __KERNEL__ */ #endif diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 34d2d649e396..3984f52181f4 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1346,7 +1346,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add struct hlist_node *node; rcu_read_lock_bh(); - hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) { + hlist_for_each_entry_rcu_bh(ifp, node, &inet6_addr_lst[hash], addr_lst) { if (!net_eq(dev_net(ifp->idev->dev), net)) continue; if (ipv6_addr_equal(&ifp->addr, addr)) { @@ -2959,7 +2959,7 @@ static struct inet6_ifaddr *if6_get_first(struct seq_file *seq) for (state->bucket = 0; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) { struct hlist_node *n; - hlist_for_each_entry_rcu(ifa, n, &inet6_addr_lst[state->bucket], + hlist_for_each_entry_rcu_bh(ifa, n, &inet6_addr_lst[state->bucket], addr_lst) if (net_eq(dev_net(ifa->idev->dev), net)) return ifa; @@ -2974,12 +2974,12 @@ static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, struct net *net = seq_file_net(seq); struct hlist_node *n = &ifa->addr_lst; - hlist_for_each_entry_continue_rcu(ifa, n, addr_lst) + hlist_for_each_entry_continue_rcu_bh(ifa, n, addr_lst) if (net_eq(dev_net(ifa->idev->dev), net)) return ifa; while (++state->bucket < IN6_ADDR_HSIZE) { - hlist_for_each_entry(ifa, n, + hlist_for_each_entry_rcu_bh(ifa, n, &inet6_addr_lst[state->bucket], addr_lst) { if (net_eq(dev_net(ifa->idev->dev), net)) return ifa; @@ -3000,7 +3000,7 @@ static struct inet6_ifaddr *if6_get_idx(struct seq_file *seq, loff_t pos) } static void *if6_seq_start(struct seq_file *seq, loff_t *pos) - __acquires(rcu) + __acquires(rcu_bh) { rcu_read_lock_bh(); return if6_get_idx(seq, *pos); @@ -3016,7 +3016,7 @@ static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos) } static void if6_seq_stop(struct seq_file *seq, void *v) - __releases(rcu) + __releases(rcu_bh) { rcu_read_unlock_bh(); } @@ -3093,7 +3093,7 @@ int ipv6_chk_home_addr(struct net *net, struct in6_addr *addr) unsigned int hash = ipv6_addr_hash(addr); rcu_read_lock_bh(); - hlist_for_each_entry_rcu(ifp, n, &inet6_addr_lst[hash], addr_lst) { + hlist_for_each_entry_rcu_bh(ifp, n, &inet6_addr_lst[hash], addr_lst) { if (!net_eq(dev_net(ifp->idev->dev), net)) continue; if (ipv6_addr_equal(&ifp->addr, addr) && @@ -3127,7 +3127,7 @@ static void addrconf_verify(unsigned long foo) for (i = 0; i < IN6_ADDR_HSIZE; i++) { restart: - hlist_for_each_entry_rcu(ifp, node, + hlist_for_each_entry_rcu_bh(ifp, node, &inet6_addr_lst[i], addr_lst) { unsigned long age; -- 2.20.1