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Diffstat (limited to 'net/ipv6/route.c')
-rw-r--r--net/ipv6/route.c90
1 files changed, 60 insertions, 30 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 1a1122a6bbf5..d15586490cec 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -318,8 +318,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = {
/* allocate dst with ip6_dst_ops */
static struct rt6_info *__ip6_dst_alloc(struct net *net,
struct net_device *dev,
- int flags,
- struct fib6_table *table)
+ int flags)
{
struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
0, DST_OBSOLETE_FORCE_CHK, flags);
@@ -336,10 +335,9 @@ static struct rt6_info *__ip6_dst_alloc(struct net *net,
static struct rt6_info *ip6_dst_alloc(struct net *net,
struct net_device *dev,
- int flags,
- struct fib6_table *table)
+ int flags)
{
- struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags, table);
+ struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags);
if (rt) {
rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC);
@@ -369,10 +367,7 @@ static void ip6_dst_destroy(struct dst_entry *dst)
struct inet6_dev *idev;
dst_destroy_metrics_generic(dst);
-
- if (rt->rt6i_pcpu)
- free_percpu(rt->rt6i_pcpu);
-
+ free_percpu(rt->rt6i_pcpu);
rt6_uncached_list_del(rt);
idev = rt->rt6i_idev;
@@ -953,8 +948,7 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
ort = (struct rt6_info *)ort->dst.from;
- rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev,
- 0, ort->rt6i_table);
+ rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev, 0);
if (!rt)
return NULL;
@@ -986,8 +980,7 @@ static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
struct rt6_info *pcpu_rt;
pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev),
- rt->dst.dev, rt->dst.flags,
- rt->rt6i_table);
+ rt->dst.dev, rt->dst.flags);
if (!pcpu_rt)
return NULL;
@@ -1000,32 +993,53 @@ static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
/* It should be called with read_lock_bh(&tb6_lock) acquired */
static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)
{
- struct rt6_info *pcpu_rt, *prev, **p;
+ struct rt6_info *pcpu_rt, **p;
p = this_cpu_ptr(rt->rt6i_pcpu);
pcpu_rt = *p;
- if (pcpu_rt)
- goto done;
+ if (pcpu_rt) {
+ dst_hold(&pcpu_rt->dst);
+ rt6_dst_from_metrics_check(pcpu_rt);
+ }
+ return pcpu_rt;
+}
+
+static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt)
+{
+ struct fib6_table *table = rt->rt6i_table;
+ struct rt6_info *pcpu_rt, *prev, **p;
pcpu_rt = ip6_rt_pcpu_alloc(rt);
if (!pcpu_rt) {
struct net *net = dev_net(rt->dst.dev);
- pcpu_rt = net->ipv6.ip6_null_entry;
- goto done;
+ dst_hold(&net->ipv6.ip6_null_entry->dst);
+ return net->ipv6.ip6_null_entry;
}
- prev = cmpxchg(p, NULL, pcpu_rt);
- if (prev) {
- /* If someone did it before us, return prev instead */
+ read_lock_bh(&table->tb6_lock);
+ if (rt->rt6i_pcpu) {
+ p = this_cpu_ptr(rt->rt6i_pcpu);
+ prev = cmpxchg(p, NULL, pcpu_rt);
+ if (prev) {
+ /* If someone did it before us, return prev instead */
+ dst_destroy(&pcpu_rt->dst);
+ pcpu_rt = prev;
+ }
+ } else {
+ /* rt has been removed from the fib6 tree
+ * before we have a chance to acquire the read_lock.
+ * In this case, don't brother to create a pcpu rt
+ * since rt is going away anyway. The next
+ * dst_check() will trigger a re-lookup.
+ */
dst_destroy(&pcpu_rt->dst);
- pcpu_rt = prev;
+ pcpu_rt = rt;
}
-
-done:
dst_hold(&pcpu_rt->dst);
rt6_dst_from_metrics_check(pcpu_rt);
+ read_unlock_bh(&table->tb6_lock);
return pcpu_rt;
}
@@ -1100,9 +1114,22 @@ redo_rt6_select:
rt->dst.lastuse = jiffies;
rt->dst.__use++;
pcpu_rt = rt6_get_pcpu_route(rt);
- read_unlock_bh(&table->tb6_lock);
+
+ if (pcpu_rt) {
+ read_unlock_bh(&table->tb6_lock);
+ } else {
+ /* We have to do the read_unlock first
+ * because rt6_make_pcpu_route() may trigger
+ * ip6_dst_gc() which will take the write_lock.
+ */
+ dst_hold(&rt->dst);
+ read_unlock_bh(&table->tb6_lock);
+ pcpu_rt = rt6_make_pcpu_route(rt);
+ dst_release(&rt->dst);
+ }
return pcpu_rt;
+
}
}
@@ -1558,7 +1585,7 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
if (unlikely(!idev))
return ERR_PTR(-ENODEV);
- rt = ip6_dst_alloc(net, dev, 0, NULL);
+ rt = ip6_dst_alloc(net, dev, 0);
if (unlikely(!rt)) {
in6_dev_put(idev);
dst = ERR_PTR(-ENOMEM);
@@ -1745,7 +1772,8 @@ int ip6_route_add(struct fib6_config *cfg)
if (!table)
goto out;
- rt = ip6_dst_alloc(net, NULL, (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT, table);
+ rt = ip6_dst_alloc(net, NULL,
+ (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT);
if (!rt) {
err = -ENOMEM;
@@ -1834,6 +1862,7 @@ int ip6_route_add(struct fib6_config *cfg)
int gwa_type;
gw_addr = &cfg->fc_gateway;
+ gwa_type = ipv6_addr_type(gw_addr);
/* if gw_addr is local we will fail to detect this in case
* address is still TENTATIVE (DAD in progress). rt6_lookup()
@@ -1841,11 +1870,12 @@ int ip6_route_add(struct fib6_config *cfg)
* prefix route was assigned to, which might be non-loopback.
*/
err = -EINVAL;
- if (ipv6_chk_addr_and_flags(net, gw_addr, NULL, 0, 0))
+ if (ipv6_chk_addr_and_flags(net, gw_addr,
+ gwa_type & IPV6_ADDR_LINKLOCAL ?
+ dev : NULL, 0, 0))
goto out;
rt->rt6i_gateway = *gw_addr;
- gwa_type = ipv6_addr_type(gw_addr);
if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
struct rt6_info *grt;
@@ -2400,7 +2430,7 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
{
struct net *net = dev_net(idev->dev);
struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev,
- DST_NOCOUNT, NULL);
+ DST_NOCOUNT);
if (!rt)
return ERR_PTR(-ENOMEM);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-13 05:32:55 +0200