From 4f70ecca9c57731b4acbe5043eb22e4416bd2368 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
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 <eric.dumazet@gmail.com>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
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;
--
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