[RTNETLINK]: Remove unnecessary locking in dump callbacks

Since we're now holding the rtnl during the entire dump operation, we can
remove additional locking for rtnl protected data. This patch does that
for all simple cases (dev_base_lock for dev_base walking, RCU protection
for FIB rule dumping).

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 5e84ade129caa260a130c4dca843df0fae7deb49..35facc0c11c24368f51c555be6bb13f072394c60 100644 (file)
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -109,7 +109,6 @@ static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
        struct net_device *dev;
        int idx;
 
-       read_lock(&dev_base_lock);
        for (dev = dev_base, idx = 0; dev; dev = dev->next) {
                /* not a bridge port */
                if (dev->br_port == NULL || idx < cb->args[0])
@@ -122,7 +121,6 @@ static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 skip:
                ++idx;
        }
-       read_unlock(&dev_base_lock);
 
        cb->args[0] = idx;
 

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index cb2dae19531b49cdf66b95b23f268b7de2de596a..8c5474e16683aa22971b1bed0390354b728a0f64 100644 (file)
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -495,8 +495,7 @@ static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
        int idx = 0;
        struct fib_rule *rule;
 
-       rcu_read_lock();
-       list_for_each_entry_rcu(rule, ops->rules_list, list) {
+       list_for_each_entry(rule, ops->rules_list, list) {
                if (idx < cb->args[1])
                        goto skip;
 
@@ -507,7 +506,6 @@ static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 skip:
                idx++;
        }
-       rcu_read_unlock();
        cb->args[1] = idx;
        rules_ops_put(ops);
 

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 62f5c7f98d17b93b52c44d02f80a42a842aec088..bc95fab0b0ceb35a1f92db14e81b1989b965e967 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -543,7 +543,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
        int s_idx = cb->args[0];
        struct net_device *dev;
 
-       read_lock(&dev_base_lock);
        for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
                if (idx < s_idx)
                        continue;
@@ -552,7 +551,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
                                     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
                        break;
        }
-       read_unlock(&dev_base_lock);
        cb->args[0] = idx;
 
        return skb->len;

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 61be2caddc576936585ab35030397f268b704280..5c2a9951b638346691b4801d27be5d036018c155 100644 (file)
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -799,7 +799,6 @@ static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
        skip_ndevs = cb->args[0];
        skip_naddr = cb->args[1];
 
-       read_lock(&dev_base_lock);
        for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
                if (idx < skip_ndevs)
                        continue;
@@ -824,8 +823,6 @@ static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
                }
        }
 done:
-       read_unlock(&dev_base_lock);
-
        cb->args[0] = idx;
        cb->args[1] = dn_idx;
 

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 9bdc79564cc65767c4e540017683fb99b509f14c..088888db8b3db18f4a02319e8041638a248fd30f 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1182,17 +1182,13 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
        int s_ip_idx, s_idx = cb->args[0];
 
        s_ip_idx = ip_idx = cb->args[1];
-       read_lock(&dev_base_lock);
        for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
                if (idx < s_idx)
                        continue;
                if (idx > s_idx)
                        s_ip_idx = 0;
-               rcu_read_lock();
-               if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
-                       rcu_read_unlock();
+               if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
                        continue;
-               }
 
                for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
                     ifa = ifa->ifa_next, ip_idx++) {
@@ -1200,16 +1196,12 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
                                continue;
                        if (inet_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
                                             cb->nlh->nlmsg_seq,
-                                            RTM_NEWADDR, NLM_F_MULTI) <= 0) {
-                               rcu_read_unlock();
+                                            RTM_NEWADDR, NLM_F_MULTI) <= 0)
                                goto done;
-                       }
                }
-               rcu_read_unlock();
        }
 
 done:
-       read_unlock(&dev_base_lock);
        cb->args[0] = idx;
        cb->args[1] = ip_idx;
 

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index eecba1886b497c872a4fc8f69a75efc948bb865a..1486f76f7878fe423c7f265e48f33570195fd8ee 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3224,7 +3224,6 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
 
        s_idx = cb->args[0];
        s_ip_idx = ip_idx = cb->args[1];
-       read_lock(&dev_base_lock);
 
        for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
                if (idx < s_idx)
@@ -3286,7 +3285,6 @@ done:
                read_unlock_bh(&idev->lock);
                in6_dev_put(idev);
        }
-       read_unlock(&dev_base_lock);
        cb->args[0] = idx;
        cb->args[1] = ip_idx;
        return skb->len;