diff --git a/include/net/dst.h b/include/net/dst.h
index 06a6765da074449e6f1fe42ee05e711e898ad372..204c19e2545682179262e7bb9a80f3c3d6baa6b3 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -101,7 +101,7 @@ struct dst_entry {
union {
struct dst_entry *next;
struct rtable __rcu *rt_next;
- struct rt6_info *rt6_next;
+ struct rt6_info __rcu *rt6_next;
struct dn_route __rcu *dn_next;
};
};
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 6bf929b509515569c5d9978f9b560350f758c664..0b438b9bcb10716b1f0a5f168b64aba53b03e012 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -68,18 +68,18 @@ struct fib6_config {
};
struct fib6_node {
- struct fib6_node *parent;
- struct fib6_node *left;
- struct fib6_node *right;
+ struct fib6_node __rcu *parent;
+ struct fib6_node __rcu *left;
+ struct fib6_node __rcu *right;
#ifdef CONFIG_IPV6_SUBTREES
- struct fib6_node *subtree;
+ struct fib6_node __rcu *subtree;
#endif
- struct rt6_info *leaf;
+ struct rt6_info __rcu *leaf;
__u16 fn_bit; /* bit key */
__u16 fn_flags;
int fn_sernum;
- struct rt6_info *rr_ptr;
+ struct rt6_info __rcu *rr_ptr;
struct rcu_head rcu;
};
@@ -91,7 +91,7 @@ struct fib6_gc_args {
#ifndef CONFIG_IPV6_SUBTREES
#define FIB6_SUBTREE(fn) NULL
#else
-#define FIB6_SUBTREE(fn) ((fn)->subtree)
+#define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
#endif
struct mx6_config {
@@ -174,6 +174,14 @@ struct rt6_info {
unused:7;
};
+#define for_each_fib6_node_rt_rcu(fn) \
+ for (rt = rcu_dereference((fn)->leaf); rt; \
+ rt = rcu_dereference(rt->dst.rt6_next))
+
+#define for_each_fib6_walker_rt(w) \
+ for (rt = (w)->leaf; rt; \
+ rt = rcu_dereference_protected(rt->dst.rt6_next, 1))
+
static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
{
return ((struct rt6_info *)dst)->rt6i_idev;
@@ -310,7 +318,7 @@ struct rt6_statistics {
struct fib6_table {
struct hlist_node tb6_hlist;
u32 tb6_id;
- rwlock_t tb6_lock;
+ spinlock_t tb6_lock;
struct fib6_node tb6_root;
struct inet_peer_base tb6_peers;
unsigned int flags;
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f86e931d555ef9bf7bee15725833a1b78fa96ab1..9854d93e45bb5ca919d55e6b875f7dc392a5dae5 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2321,12 +2321,12 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
if (!table)
return NULL;
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0, true);
if (!fn)
goto out;
- for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_node_rt_rcu(fn) {
if (rt->dst.dev->ifindex != dev->ifindex)
continue;
if ((rt->rt6i_flags & flags) != flags)
@@ -2338,7 +2338,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
break;
}
out:
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
return rt;
}
@@ -5898,10 +5898,9 @@ void addrconf_disable_policy_idev(struct inet6_dev *idev, int val)
spin_lock(&ifa->lock);
if (ifa->rt) {
struct rt6_info *rt = ifa->rt;
- struct fib6_table *table = rt->rt6i_table;
int cpu;
- read_lock(&table->tb6_lock);
+ rcu_read_lock();
addrconf_set_nopolicy(ifa->rt, val);
if (rt->rt6i_pcpu) {
for_each_possible_cpu(cpu) {
@@ -5911,7 +5910,7 @@ void addrconf_disable_policy_idev(struct inet6_dev *idev, int val)
addrconf_set_nopolicy(*rtp, val);
}
}
- read_unlock(&table->tb6_lock);
+ rcu_read_unlock();
}
spin_unlock(&ifa->lock);
}
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index cf6137e81408bec9bce7edc06aaf1fd2f2f2af4c..3f95908b39c3d628fc6f642d07c66b78b8b70712 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -54,8 +54,12 @@ struct fib6_cleaner {
#define FWS_INIT FWS_L
#endif
-static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
-static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
+static struct rt6_info *fib6_find_prefix(struct net *net,
+ struct fib6_table *table,
+ struct fib6_node *fn);
+static struct fib6_node *fib6_repair_tree(struct net *net,
+ struct fib6_table *table,
+ struct fib6_node *fn);
static int fib6_walk(struct net *net, struct fib6_walker *w);
static int fib6_walk_continue(struct fib6_walker *w);
@@ -107,12 +111,12 @@ void fib6_update_sernum(struct rt6_info *rt)
struct net *net = dev_net(rt->dst.dev);
struct fib6_node *fn;
- write_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
fn = rcu_dereference_protected(rt->rt6i_node,
lockdep_is_held(&table->tb6_lock));
if (fn)
fn->fn_sernum = fib6_new_sernum(net);
- write_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
}
/*
@@ -207,8 +211,7 @@ static void fib6_link_table(struct net *net, struct fib6_table *tb)
* Initialize table lock at a single place to give lockdep a key,
* tables aren't visible prior to being linked to the list.
*/
- rwlock_init(&tb->tb6_lock);
-
+ spin_lock_init(&tb->tb6_lock);
h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
/*
@@ -227,7 +230,8 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
table = kzalloc(sizeof(*table), GFP_ATOMIC);
if (table) {
table->tb6_id = id;
- table->tb6_root.leaf = net->ipv6.ip6_null_entry;
+ rcu_assign_pointer(table->tb6_root.leaf,
+ net->ipv6.ip6_null_entry);
table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
inet_peer_base_init(&table->tb6_peers);
}
@@ -324,11 +328,8 @@ unsigned int fib6_tables_seq_read(struct net *net)
struct hlist_head *head = &net->ipv6.fib_table_hash[h];
struct fib6_table *tb;
- hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
- read_lock_bh(&tb->tb6_lock);
+ hlist_for_each_entry_rcu(tb, head, tb6_hlist)
fib_seq += tb->fib_seq;
- read_unlock_bh(&tb->tb6_lock);
- }
}
rcu_read_unlock();
@@ -374,7 +375,7 @@ static int fib6_node_dump(struct fib6_walker *w)
{
struct rt6_info *rt;
- for (rt = w->leaf; rt; rt = rt->dst.rt6_next)
+ for_each_fib6_walker_rt(w)
fib6_rt_dump(rt, w->args);
w->leaf = NULL;
return 0;
@@ -384,9 +385,9 @@ static void fib6_table_dump(struct net *net, struct fib6_table *tb,
struct fib6_walker *w)
{
w->root = &tb->tb6_root;
- read_lock_bh(&tb->tb6_lock);
+ spin_lock_bh(&tb->tb6_lock);
fib6_walk(net, w);
- read_unlock_bh(&tb->tb6_lock);
+ spin_unlock_bh(&tb->tb6_lock);
}
/* Called with rcu_read_lock() */
@@ -423,7 +424,7 @@ static int fib6_dump_node(struct fib6_walker *w)
int res;
struct rt6_info *rt;
- for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_walker_rt(w) {
res = rt6_dump_route(rt, w->args);
if (res < 0) {
/* Frame is full, suspend walking */
@@ -482,9 +483,9 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
w->count = 0;
w->skip = 0;
- read_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
res = fib6_walk(net, w);
- read_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
if (res > 0) {
cb->args[4] = 1;
cb->args[5] = w->root->fn_sernum;
@@ -499,9 +500,9 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
} else
w->skip = 0;
- read_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
res = fib6_walk_continue(w);
- read_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
if (res <= 0) {
fib6_walker_unlink(net, w);
cb->args[4] = 0;
@@ -582,11 +583,12 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
* node.
*/
-static struct fib6_node *fib6_add_1(struct fib6_node *root,
- struct in6_addr *addr, int plen,
- int offset, int allow_create,
- int replace_required,
- struct netlink_ext_ack *extack)
+static struct fib6_node *fib6_add_1(struct fib6_table *table,
+ struct fib6_node *root,
+ struct in6_addr *addr, int plen,
+ int offset, int allow_create,
+ int replace_required,
+ struct netlink_ext_ack *extack)
{
struct fib6_node *fn, *in, *ln;
struct fib6_node *pn = NULL;
@@ -601,7 +603,9 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
fn = root;
do {
- key = (struct rt6key *)((u8 *)fn->leaf + offset);
+ struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ key = (struct rt6key *)((u8 *)leaf + offset);
/*
* Prefix match
@@ -627,8 +631,8 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
if (plen == fn->fn_bit) {
/* clean up an intermediate node */
if (!(fn->fn_flags & RTN_RTINFO)) {
- rt6_release(fn->leaf);
- fn->leaf = NULL;
+ RCU_INIT_POINTER(fn->leaf, NULL);
+ rt6_release(leaf);
}
return fn;
@@ -641,7 +645,11 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
/* Try to walk down on tree. */
dir = addr_bit_set(addr, fn->fn_bit);
pn = fn;
- fn = dir ? fn->right : fn->left;
+ fn = dir ?
+ rcu_dereference_protected(fn->right,
+ lockdep_is_held(&table->tb6_lock)) :
+ rcu_dereference_protected(fn->left,
+ lockdep_is_held(&table->tb6_lock));
} while (fn);
if (!allow_create) {
@@ -672,13 +680,12 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
if (!ln)
return ERR_PTR(-ENOMEM);
ln->fn_bit = plen;
-
- ln->parent = pn;
+ RCU_INIT_POINTER(ln->parent, pn);
if (dir)
- pn->right = ln;
+ rcu_assign_pointer(pn->right, ln);
else
- pn->left = ln;
+ rcu_assign_pointer(pn->left, ln);
return ln;
@@ -692,7 +699,8 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
* and the current
*/
- pn = fn->parent;
+ pn = rcu_dereference_protected(fn->parent,
+ lockdep_is_held(&table->tb6_lock));
/* find 1st bit in difference between the 2 addrs.
@@ -729,27 +737,28 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
in->fn_bit = bit;
- in->parent = pn;
+ RCU_INIT_POINTER(in->parent, pn);
in->leaf = fn->leaf;
- atomic_inc(&in->leaf->rt6i_ref);
+ atomic_inc(&rcu_dereference_protected(in->leaf,
+ lockdep_is_held(&table->tb6_lock))->rt6i_ref);
/* update parent pointer */
if (dir)
- pn->right = in;
+ rcu_assign_pointer(pn->right, in);
else
- pn->left = in;
+ rcu_assign_pointer(pn->left, in);
ln->fn_bit = plen;
- ln->parent = in;
- fn->parent = in;
+ RCU_INIT_POINTER(ln->parent, in);
+ rcu_assign_pointer(fn->parent, in);
if (addr_bit_set(addr, bit)) {
- in->right = ln;
- in->left = fn;
+ rcu_assign_pointer(in->right, ln);
+ rcu_assign_pointer(in->left, fn);
} else {
- in->left = ln;
- in->right = fn;
+ rcu_assign_pointer(in->left, ln);
+ rcu_assign_pointer(in->right, fn);
}
} else { /* plen <= bit */
@@ -766,19 +775,19 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
ln->fn_bit = plen;
- ln->parent = pn;
-
- if (dir)
- pn->right = ln;
- else
- pn->left = ln;
+ RCU_INIT_POINTER(ln->parent, pn);
if (addr_bit_set(&key->addr, plen))
- ln->right = fn;
+ RCU_INIT_POINTER(ln->right, fn);
else
- ln->left = fn;
+ RCU_INIT_POINTER(ln->left, fn);
+
+ rcu_assign_pointer(fn->parent, ln);
- fn->parent = ln;
+ if (dir)
+ rcu_assign_pointer(pn->right, ln);
+ else
+ rcu_assign_pointer(pn->left, ln);
}
return ln;
}
@@ -824,6 +833,8 @@ static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
struct net *net)
{
+ struct fib6_table *table = rt->rt6i_table;
+
if (atomic_read(&rt->rt6i_ref) != 1) {
/* This route is used as dummy address holder in some split
* nodes. It is not leaked, but it still holds other resources,
@@ -832,12 +843,17 @@ static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
* to still alive ones.
*/
while (fn) {
- if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
- fn->leaf = fib6_find_prefix(net, fn);
- atomic_inc(&fn->leaf->rt6i_ref);
+ struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ struct rt6_info *new_leaf;
+ if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
+ new_leaf = fib6_find_prefix(net, table, fn);
+ atomic_inc(&new_leaf->rt6i_ref);
+ rcu_assign_pointer(fn->leaf, new_leaf);
rt6_release(rt);
}
- fn = fn->parent;
+ fn = rcu_dereference_protected(fn->parent,
+ lockdep_is_held(&table->tb6_lock));
}
}
}
@@ -849,9 +865,11 @@ static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
struct nl_info *info, struct mx6_config *mxc)
{
+ struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
struct rt6_info *iter = NULL;
- struct rt6_info **ins;
- struct rt6_info **fallback_ins = NULL;
+ struct rt6_info __rcu **ins;
+ struct rt6_info __rcu **fallback_ins = NULL;
int replace = (info->nlh &&
(info->nlh->nlmsg_flags & NLM_F_REPLACE));
int add = (!info->nlh ||
@@ -866,7 +884,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
ins = &fn->leaf;
- for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
+ for (iter = leaf; iter;
+ iter = rcu_dereference_protected(iter->dst.rt6_next,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock))) {
/*
* Search for duplicates
*/
@@ -928,7 +948,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
if (fallback_ins && !found) {
/* No ECMP-able route found, replace first non-ECMP one */
ins = fallback_ins;
- iter = *ins;
+ iter = rcu_dereference_protected(*ins,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
found++;
}
@@ -942,7 +963,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
struct rt6_info *sibling, *temp_sibling;
/* Find the first route that have the same metric */
- sibling = fn->leaf;
+ sibling = leaf;
while (sibling) {
if (sibling->rt6i_metric == rt->rt6i_metric &&
rt6_qualify_for_ecmp(sibling)) {
@@ -950,7 +971,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
&sibling->rt6i_siblings);
break;
}
- sibling = sibling->dst.rt6_next;
+ sibling = rcu_dereference_protected(sibling->dst.rt6_next,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
}
/* For each sibling in the list, increment the counter of
* siblings. BUG() if counters does not match, list of siblings
@@ -979,10 +1001,10 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
if (err)
return err;
- rt->dst.rt6_next = iter;
- *ins = rt;
- rcu_assign_pointer(rt->rt6i_node, fn);
+ rcu_assign_pointer(rt->dst.rt6_next, iter);
atomic_inc(&rt->rt6i_ref);
+ rcu_assign_pointer(rt->rt6i_node, fn);
+ rcu_assign_pointer(*ins, rt);
call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_ADD,
rt);
if (!info->skip_notify)
@@ -1008,10 +1030,10 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
if (err)
return err;
- *ins = rt;
+ atomic_inc(&rt->rt6i_ref);
rcu_assign_pointer(rt->rt6i_node, fn);
rt->dst.rt6_next = iter->dst.rt6_next;
- atomic_inc(&rt->rt6i_ref);
+ rcu_assign_pointer(*ins, rt);
call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_REPLACE,
rt);
if (!info->skip_notify)
@@ -1023,14 +1045,15 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
nsiblings = iter->rt6i_nsiblings;
iter->rt6i_node = NULL;
fib6_purge_rt(iter, fn, info->nl_net);
- if (fn->rr_ptr == iter)
+ if (rcu_access_pointer(fn->rr_ptr) == iter)
fn->rr_ptr = NULL;
rt6_release(iter);
if (nsiblings) {
/* Replacing an ECMP route, remove all siblings */
ins = &rt->dst.rt6_next;
- iter = *ins;
+ iter = rcu_dereference_protected(*ins,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
while (iter) {
if (iter->rt6i_metric > rt->rt6i_metric)
break;
@@ -1038,14 +1061,15 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
*ins = iter->dst.rt6_next;
iter->rt6i_node = NULL;
fib6_purge_rt(iter, fn, info->nl_net);
- if (fn->rr_ptr == iter)
+ if (rcu_access_pointer(fn->rr_ptr) == iter)
fn->rr_ptr = NULL;
rt6_release(iter);
nsiblings--;
} else {
ins = &iter->dst.rt6_next;
}
- iter = *ins;
+ iter = rcu_dereference_protected(*ins,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
}
WARN_ON(nsiblings != 0);
}
@@ -1079,7 +1103,8 @@ static void fib6_update_sernum_upto_root(struct rt6_info *rt,
smp_wmb();
while (fn) {
fn->fn_sernum = sernum;
- fn = fn->parent;
+ fn = rcu_dereference_protected(fn->parent,
+ lockdep_is_held(&rt->rt6i_table->tb6_lock));
}
}
@@ -1087,12 +1112,14 @@ static void fib6_update_sernum_upto_root(struct rt6_info *rt,
* Add routing information to the routing tree.
* <destination addr>/<source addr>
* with source addr info in sub-trees
+ * Need to own table->tb6_lock
*/
int fib6_add(struct fib6_node *root, struct rt6_info *rt,
struct nl_info *info, struct mx6_config *mxc,
struct netlink_ext_ack *extack)
{
+ struct fib6_table *table = rt->rt6i_table;
struct fib6_node *fn, *pn = NULL;
int err = -ENOMEM;
int allow_create = 1;
@@ -1113,7 +1140,8 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
if (!allow_create && !replace_required)
pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
- fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
+ fn = fib6_add_1(table, root,
+ &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
offsetof(struct rt6_info, rt6i_dst), allow_create,
replace_required, extack);
if (IS_ERR(fn)) {
@@ -1128,7 +1156,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
if (rt->rt6i_src.plen) {
struct fib6_node *sn;
- if (!fn->subtree) {
+ if (!rcu_access_pointer(fn->subtree)) {
struct fib6_node *sfn;
/*
@@ -1146,13 +1174,14 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
if (!sfn)
goto failure;
- sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
+ rcu_assign_pointer(sfn->leaf,
+ info->nl_net->ipv6.ip6_null_entry);
sfn->fn_flags = RTN_ROOT;
/* Now add the first leaf node to new subtree */
- sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
+ sn = fib6_add_1(table, sfn, &rt->rt6i_src.addr,
rt->rt6i_src.plen,
offsetof(struct rt6_info, rt6i_src),
allow_create, replace_required, extack);
@@ -1168,10 +1197,10 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
}
/* Now link new subtree to main tree */
- sfn->parent = fn;
- fn->subtree = sfn;
+ rcu_assign_pointer(sfn->parent, fn);
+ rcu_assign_pointer(fn->subtree, sfn);
} else {
- sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
+ sn = fib6_add_1(table, FIB6_SUBTREE(fn), &rt->rt6i_src.addr,
rt->rt6i_src.plen,
offsetof(struct rt6_info, rt6i_src),
allow_create, replace_required, extack);
@@ -1182,9 +1211,9 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
}
}
- if (!fn->leaf) {
- fn->leaf = rt;
+ if (!rcu_access_pointer(fn->leaf)) {
atomic_inc(&rt->rt6i_ref);
+ rcu_assign_pointer(fn->leaf, rt);
}
fn = sn;
}
@@ -1203,19 +1232,23 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
* If fib6_add_1 has cleared the old leaf pointer in the
* super-tree leaf node we have to find a new one for it.
*/
- if (pn != fn && pn->leaf == rt) {
- pn->leaf = NULL;
+ struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ if (pn != fn && pn_leaf == rt) {
+ pn_leaf = NULL;
+ RCU_INIT_POINTER(pn->leaf, NULL);
atomic_dec(&rt->rt6i_ref);
}
- if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
- pn->leaf = fib6_find_prefix(info->nl_net, pn);
+ if (pn != fn && !pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
+ pn_leaf = fib6_find_prefix(info->nl_net, table, pn);
#if RT6_DEBUG >= 2
- if (!pn->leaf) {
- WARN_ON(pn->leaf == NULL);
- pn->leaf = info->nl_net->ipv6.ip6_null_entry;
+ if (!pn_leaf) {
+ WARN_ON(!pn_leaf);
+ pn_leaf = info->nl_net->ipv6.ip6_null_entry;
}
#endif
- atomic_inc(&pn->leaf->rt6i_ref);
+ atomic_inc(&pn_leaf->rt6i_ref);
+ rcu_assign_pointer(pn->leaf, pn_leaf);
}
#endif
goto failure;
@@ -1230,7 +1263,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
* fn->leaf.
*/
if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
- fib6_repair_tree(info->nl_net, fn);
+ fib6_repair_tree(info->nl_net, table, fn);
/* Always release dst as dst->__refcnt is guaranteed
* to be taken before entering this function
*/
@@ -1268,7 +1301,8 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
dir = addr_bit_set(args->addr, fn->fn_bit);
- next = dir ? fn->right : fn->left;
+ next = dir ? rcu_dereference(fn->right) :
+ rcu_dereference(fn->left);
if (next) {
fn = next;
@@ -1278,8 +1312,10 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
}
while (fn) {
- if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
- struct rt6_info *leaf = fn->leaf;
+ struct fib6_node *subtree = FIB6_SUBTREE(fn);
+
+ if (subtree || fn->fn_flags & RTN_RTINFO) {
+ struct rt6_info *leaf = rcu_dereference(fn->leaf);
struct rt6key *key;
if (!leaf)
@@ -1289,10 +1325,9 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
#ifdef CONFIG_IPV6_SUBTREES
- if (fn->subtree) {
+ if (subtree) {
struct fib6_node *sfn;
- sfn = fib6_lookup_1(fn->subtree,
- args + 1);
+ sfn = fib6_lookup_1(subtree, args + 1);
if (!sfn)
goto backtrack;
fn = sfn;
@@ -1306,12 +1341,14 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
if (fn->fn_flags & RTN_ROOT)
break;
- fn = fn->parent;
+ fn = rcu_dereference(fn->parent);
}
return NULL;
}
+/* called with rcu_read_lock() held
+ */
struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
@@ -1359,7 +1396,7 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root,
struct fib6_node *fn, *prev = NULL;
for (fn = root; fn ; ) {
- struct rt6_info *leaf = fn->leaf;
+ struct rt6_info *leaf = rcu_dereference(fn->leaf);
struct rt6key *key;
/* This node is being deleted */
@@ -1389,9 +1426,9 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root,
* We have more bits to go
*/
if (addr_bit_set(addr, fn->fn_bit))
- fn = fn->right;
+ fn = rcu_dereference(fn->right);
else
- fn = fn->left;
+ fn = rcu_dereference(fn->left);
}
out:
if (exact_match)
@@ -1413,9 +1450,11 @@ struct fib6_node *fib6_locate(struct fib6_node *root,
#ifdef CONFIG_IPV6_SUBTREES
if (src_len) {
+ struct fib6_node *subtree = FIB6_SUBTREE(fn);
+
WARN_ON(saddr == NULL);
- if (fn && fn->subtree)
- fn = fib6_locate_1(fn->subtree, saddr, src_len,
+ if (fn && subtree)
+ fn = fib6_locate_1(subtree, saddr, src_len,
offsetof(struct rt6_info, rt6i_src),
exact_match);
}
@@ -1433,16 +1472,26 @@ struct fib6_node *fib6_locate(struct fib6_node *root,
*
*/
-static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
+static struct rt6_info *fib6_find_prefix(struct net *net,
+ struct fib6_table *table,
+ struct fib6_node *fn)
{
+ struct fib6_node *child_left, *child_right;
+
if (fn->fn_flags & RTN_ROOT)
return net->ipv6.ip6_null_entry;
while (fn) {
- if (fn->left)
- return fn->left->leaf;
- if (fn->right)
- return fn->right->leaf;
+ child_left = rcu_dereference_protected(fn->left,
+ lockdep_is_held(&table->tb6_lock));
+ child_right = rcu_dereference_protected(fn->right,
+ lockdep_is_held(&table->tb6_lock));
+ if (child_left)
+ return rcu_dereference_protected(child_left->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ if (child_right)
+ return rcu_dereference_protected(child_right->leaf,
+ lockdep_is_held(&table->tb6_lock));
fn = FIB6_SUBTREE(fn);
}
@@ -1452,31 +1501,49 @@ static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
/*
* Called to trim the tree of intermediate nodes when possible. "fn"
* is the node we want to try and remove.
+ * Need to own table->tb6_lock
*/
static struct fib6_node *fib6_repair_tree(struct net *net,
- struct fib6_node *fn)
+ struct fib6_table *table,
+ struct fib6_node *fn)
{
int children;
int nstate;
- struct fib6_node *child, *pn;
+ struct fib6_node *child;
struct fib6_walker *w;
int iter = 0;
for (;;) {
+ struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
+ lockdep_is_held(&table->tb6_lock));
+ struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
+ lockdep_is_held(&table->tb6_lock));
+ struct fib6_node *pn = rcu_dereference_protected(fn->parent,
+ lockdep_is_held(&table->tb6_lock));
+ struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
+ lockdep_is_held(&table->tb6_lock));
+ struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
+ lockdep_is_held(&table->tb6_lock));
+ struct rt6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
+ lockdep_is_held(&table->tb6_lock));
+ struct rt6_info *new_fn_leaf;
+
RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
iter++;
WARN_ON(fn->fn_flags & RTN_RTINFO);
WARN_ON(fn->fn_flags & RTN_TL_ROOT);
- WARN_ON(fn->leaf);
+ WARN_ON(fn_leaf);
children = 0;
child = NULL;
- if (fn->right)
- child = fn->right, children |= 1;
- if (fn->left)
- child = fn->left, children |= 2;
+ if (fn_r)
+ child = fn_r, children |= 1;
+ if (fn_l)
+ child = fn_l, children |= 2;
if (children == 3 || FIB6_SUBTREE(fn)
#ifdef CONFIG_IPV6_SUBTREES
@@ -1484,36 +1551,36 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
|| (children && fn->fn_flags & RTN_ROOT)
#endif
) {
- fn->leaf = fib6_find_prefix(net, fn);
+ new_fn_leaf = fib6_find_prefix(net, table, fn);
#if RT6_DEBUG >= 2
- if (!fn->leaf) {
- WARN_ON(!fn->leaf);
- fn->leaf = net->ipv6.ip6_null_entry;
+ if (!new_fn_leaf) {
+ WARN_ON(!new_fn_leaf);
+ new_fn_leaf = net->ipv6.ip6_null_entry;
}
#endif
- atomic_inc(&fn->leaf->rt6i_ref);
- return fn->parent;
+ atomic_inc(&new_fn_leaf->rt6i_ref);
+ rcu_assign_pointer(fn->leaf, new_fn_leaf);
+ return pn;
}
- pn = fn->parent;
#ifdef CONFIG_IPV6_SUBTREES
if (FIB6_SUBTREE(pn) == fn) {
WARN_ON(!(fn->fn_flags & RTN_ROOT));
- FIB6_SUBTREE(pn) = NULL;
+ RCU_INIT_POINTER(pn->subtree, NULL);
nstate = FWS_L;
} else {
WARN_ON(fn->fn_flags & RTN_ROOT);
#endif
- if (pn->right == fn)
- pn->right = child;
- else if (pn->left == fn)
- pn->left = child;
+ if (pn_r == fn)
+ rcu_assign_pointer(pn->right, child);
+ else if (pn_l == fn)
+ rcu_assign_pointer(pn->left, child);
#if RT6_DEBUG >= 2
else
WARN_ON(1);
#endif
if (child)
- child->parent = pn;
+ rcu_assign_pointer(child->parent, pn);
nstate = FWS_R;
#ifdef CONFIG_IPV6_SUBTREES
}
@@ -1546,17 +1613,18 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
return pn;
- rt6_release(pn->leaf);
- pn->leaf = NULL;
+ RCU_INIT_POINTER(pn->leaf, NULL);
+ rt6_release(pn_leaf);
fn = pn;
}
}
-static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
- struct nl_info *info)
+static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
+ struct rt6_info __rcu **rtp, struct nl_info *info)
{
struct fib6_walker *w;
- struct rt6_info *rt = *rtp;
+ struct rt6_info *rt = rcu_dereference_protected(*rtp,
+ lockdep_is_held(&table->tb6_lock));
struct net *net = info->nl_net;
RT6_TRACE("fib6_del_route\n");
@@ -1573,7 +1641,7 @@ static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
rt6_flush_exceptions(rt);
/* Reset round-robin state, if necessary */
- if (fn->rr_ptr == rt)
+ if (rcu_access_pointer(fn->rr_ptr) == rt)
fn->rr_ptr = NULL;
/* Remove this entry from other siblings */
@@ -1592,20 +1660,19 @@ static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
FOR_WALKERS(net, w) {
if (w->state == FWS_C && w->leaf == rt) {
RT6_TRACE("walker %p adjusted by delroute\n", w);
- w->leaf = rt->dst.rt6_next;
+ w->leaf = rcu_dereference_protected(rt->dst.rt6_next,
+ lockdep_is_held(&table->tb6_lock));
if (!w->leaf)
w->state = FWS_U;
}
}
read_unlock(&net->ipv6.fib6_walker_lock);
- rt->dst.rt6_next = NULL;
-
/* If it was last route, expunge its radix tree node */
- if (!fn->leaf) {
+ if (!rcu_access_pointer(fn->leaf)) {
fn->fn_flags &= ~RTN_RTINFO;
net->ipv6.rt6_stats->fib_route_nodes--;
- fn = fib6_repair_tree(net, fn);
+ fn = fib6_repair_tree(net, table, fn);
}
fib6_purge_rt(rt, fn, net);
@@ -1616,12 +1683,15 @@ static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
rt6_release(rt);
}
+/* Need to own table->tb6_lock */
int fib6_del(struct rt6_info *rt, struct nl_info *info)
{
struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
lockdep_is_held(&rt->rt6i_table->tb6_lock));
+ struct fib6_table *table = rt->rt6i_table;
struct net *net = info->nl_net;
- struct rt6_info **rtp;
+ struct rt6_info __rcu **rtp;
+ struct rt6_info __rcu **rtp_next;
#if RT6_DEBUG >= 2
if (rt->dst.obsolete > 0) {
@@ -1642,11 +1712,14 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
* Walk the leaf entries looking for ourself
*/
- for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
- if (*rtp == rt) {
- fib6_del_route(fn, rtp, info);
+ for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
+ struct rt6_info *cur = rcu_dereference_protected(*rtp,
+ lockdep_is_held(&table->tb6_lock));
+ if (rt == cur) {
+ fib6_del_route(table, fn, rtp, info);
return 0;
}
+ rtp_next = &cur->dst.rt6_next;
}
return -ENOENT;
}
@@ -1673,11 +1746,13 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
* 0 -> walk is complete.
* >0 -> walk is incomplete (i.e. suspended)
* <0 -> walk is terminated by an error.
+ *
+ * This function is called with tb6_lock held.
*/
static int fib6_walk_continue(struct fib6_walker *w)
{
- struct fib6_node *fn, *pn;
+ struct fib6_node *fn, *pn, *left, *right;
/* w->root should always be table->tb6_root */
WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
@@ -1697,20 +1772,22 @@ static int fib6_walk_continue(struct fib6_walker *w)
w->state = FWS_L;
#endif
case FWS_L:
- if (fn->left) {
- w->node = fn->left;
+ left = rcu_dereference_protected(fn->left, 1);
+ if (left) {
+ w->node = left;
w->state = FWS_INIT;
continue;
}
w->state = FWS_R;
case FWS_R:
- if (fn->right) {
- w->node = fn->right;
+ right = rcu_dereference_protected(fn->right, 1);
+ if (right) {
+ w->node = right;
w->state = FWS_INIT;
continue;
}
w->state = FWS_C;
- w->leaf = fn->leaf;
+ w->leaf = rcu_dereference_protected(fn->leaf, 1);
case FWS_C:
if (w->leaf && fn->fn_flags & RTN_RTINFO) {
int err;
@@ -1732,7 +1809,9 @@ static int fib6_walk_continue(struct fib6_walker *w)
case FWS_U:
if (fn == w->root)
return 0;
- pn = fn->parent;
+ pn = rcu_dereference_protected(fn->parent, 1);
+ left = rcu_dereference_protected(pn->left, 1);
+ right = rcu_dereference_protected(pn->right, 1);
w->node = pn;
#ifdef CONFIG_IPV6_SUBTREES
if (FIB6_SUBTREE(pn) == fn) {
@@ -1741,13 +1820,13 @@ static int fib6_walk_continue(struct fib6_walker *w)
continue;
}
#endif
- if (pn->left == fn) {
+ if (left == fn) {
w->state = FWS_R;
continue;
}
- if (pn->right == fn) {
+ if (right == fn) {
w->state = FWS_C;
- w->leaf = w->node->leaf;
+ w->leaf = rcu_dereference_protected(w->node->leaf, 1);
continue;
}
#if RT6_DEBUG >= 2
@@ -1790,7 +1869,7 @@ static int fib6_clean_node(struct fib6_walker *w)
return 0;
}
- for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_walker_rt(w) {
res = c->func(rt, c->arg);
if (res < 0) {
w->leaf = rt;
@@ -1850,10 +1929,10 @@ static void __fib6_clean_all(struct net *net,
for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
head = &net->ipv6.fib_table_hash[h];
hlist_for_each_entry_rcu(table, head, tb6_hlist) {
- write_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
fib6_clean_tree(net, &table->tb6_root,
func, sernum, arg);
- write_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
}
}
rcu_read_unlock();
@@ -1967,7 +2046,8 @@ static int __net_init fib6_net_init(struct net *net)
goto out_fib_table_hash;
net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
- net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
+ rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
+ net->ipv6.ip6_null_entry);
net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
@@ -1978,7 +2058,8 @@ static int __net_init fib6_net_init(struct net *net)
if (!net->ipv6.fib6_local_tbl)
goto out_fib6_main_tbl;
net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
- net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
+ rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
+ net->ipv6.ip6_null_entry);
net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
@@ -2108,7 +2189,9 @@ static int ipv6_route_yield(struct fib6_walker *w)
return 1;
do {
- iter->w.leaf = iter->w.leaf->dst.rt6_next;
+ iter->w.leaf = rcu_dereference_protected(
+ iter->w.leaf->dst.rt6_next,
+ lockdep_is_held(&iter->tbl->tb6_lock));
iter->skip--;
if (!iter->skip && iter->w.leaf)
return 1;
@@ -2173,7 +2256,7 @@ static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
if (!v)
goto iter_table;
- n = ((struct rt6_info *)v)->dst.rt6_next;
+ n = rcu_dereference(((struct rt6_info *)v)->dst.rt6_next);
if (n) {
++*pos;
return n;
@@ -2181,9 +2264,9 @@ static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
iter_table:
ipv6_route_check_sernum(iter);
- read_lock(&iter->tbl->tb6_lock);
+ spin_lock_bh(&iter->tbl->tb6_lock);
r = fib6_walk_continue(&iter->w);
- read_unlock(&iter->tbl->tb6_lock);
+ spin_unlock_bh(&iter->tbl->tb6_lock);
if (r > 0) {
if (v)
++*pos;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 24b80f43bbfbb6e6c2fdd8944be8ebc25c191391..cf44d0994b1e844901c026f90caa113378afba04 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -488,7 +488,7 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
}
/*
- * Route lookup. Any table->tb6_lock is implied.
+ * Route lookup. rcu_read_lock() should be held.
*/
static inline struct rt6_info *rt6_device_match(struct net *net,
@@ -503,7 +503,7 @@ static inline struct rt6_info *rt6_device_match(struct net *net,
if (!oif && ipv6_addr_any(saddr))
goto out;
- for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
+ for (sprt = rt; sprt; sprt = rcu_dereference(sprt->dst.rt6_next)) {
struct net_device *dev = sprt->dst.dev;
if (oif) {
@@ -722,7 +722,7 @@ static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
match = NULL;
cont = NULL;
- for (rt = rr_head; rt; rt = rt->dst.rt6_next) {
+ for (rt = rr_head; rt; rt = rcu_dereference(rt->dst.rt6_next)) {
if (rt->rt6i_metric != metric) {
cont = rt;
break;
@@ -731,7 +731,8 @@ static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
match = find_match(rt, oif, strict, &mpri, match, do_rr);
}
- for (rt = leaf; rt && rt != rr_head; rt = rt->dst.rt6_next) {
+ for (rt = leaf; rt && rt != rr_head;
+ rt = rcu_dereference(rt->dst.rt6_next)) {
if (rt->rt6i_metric != metric) {
cont = rt;
break;
@@ -743,7 +744,7 @@ static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
if (match || !cont)
return match;
- for (rt = cont; rt; rt = rt->dst.rt6_next)
+ for (rt = cont; rt; rt = rcu_dereference(rt->dst.rt6_next))
match = find_match(rt, oif, strict, &mpri, match, do_rr);
return match;
@@ -752,7 +753,7 @@ static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn,
int oif, int strict)
{
- struct rt6_info *leaf = fn->leaf;
+ struct rt6_info *leaf = rcu_dereference(fn->leaf);
struct rt6_info *match, *rt0;
bool do_rr = false;
int key_plen;
@@ -760,9 +761,9 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn,
if (!leaf)
return net->ipv6.ip6_null_entry;
- rt0 = fn->rr_ptr;
+ rt0 = rcu_dereference(fn->rr_ptr);
if (!rt0)
- fn->rr_ptr = rt0 = leaf;
+ rt0 = leaf;
/* Double check to make sure fn is not an intermediate node
* and fn->leaf does not points to its child's leaf
@@ -781,14 +782,19 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn,
&do_rr);
if (do_rr) {
- struct rt6_info *next = rt0->dst.rt6_next;
+ struct rt6_info *next = rcu_dereference(rt0->dst.rt6_next);
/* no entries matched; do round-robin */
if (!next || next->rt6i_metric != rt0->rt6i_metric)
next = leaf;
- if (next != rt0)
- fn->rr_ptr = next;
+ if (next != rt0) {
+ spin_lock_bh(&leaf->rt6i_table->tb6_lock);
+ /* make sure next is not being deleted from the tree */
+ if (next->rt6i_node)
+ rcu_assign_pointer(fn->rr_ptr, next);
+ spin_unlock_bh(&leaf->rt6i_table->tb6_lock);
+ }
}
return match ? match : net->ipv6.ip6_null_entry;
@@ -878,13 +884,14 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
struct in6_addr *saddr)
{
- struct fib6_node *pn;
+ struct fib6_node *pn, *sn;
while (1) {
if (fn->fn_flags & RTN_TL_ROOT)
return NULL;
- pn = fn->parent;
- if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn)
- fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr);
+ pn = rcu_dereference(fn->parent);
+ sn = FIB6_SUBTREE(pn);
+ if (sn && sn != fn)
+ fn = fib6_lookup(sn, NULL, saddr);
else
fn = pn;
if (fn->fn_flags & RTN_RTINFO)
@@ -916,13 +923,19 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
struct rt6_info *rt, *rt_cache;
struct fib6_node *fn;
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
- rt = fn->leaf;
- rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
- if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
- rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
+ rt = rcu_dereference(fn->leaf);
+ if (!rt) {
+ rt = net->ipv6.ip6_null_entry;
+ } else {
+ rt = rt6_device_match(net, rt, &fl6->saddr,
+ fl6->flowi6_oif, flags);
+ if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
+ rt = rt6_multipath_select(rt, fl6,
+ fl6->flowi6_oif, flags);
+ }
if (rt == net->ipv6.ip6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
@@ -936,7 +949,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
if (ip6_hold_safe(net, &rt, true))
dst_use_noref(&rt->dst, jiffies);
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
@@ -990,9 +1003,9 @@ static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info,
struct fib6_table *table;
table = rt->rt6i_table;
- write_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
err = fib6_add(&table->tb6_root, rt, info, mxc, extack);
- write_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
return err;
}
@@ -1090,7 +1103,7 @@ static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
return pcpu_rt;
}
-/* It should be called with read_lock_bh(&tb6_lock) acquired */
+/* It should be called with rcu_read_lock() acquired */
static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)
{
struct rt6_info *pcpu_rt, **p;
@@ -1632,7 +1645,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
if (net->ipv6.devconf_all->forwarding == 0)
strict |= RT6_LOOKUP_F_REACHABLE;
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
saved_fn = fn;
@@ -1662,7 +1675,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
rt = rt_cache;
if (rt == net->ipv6.ip6_null_entry) {
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
dst_hold(&rt->dst);
trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
return rt;
@@ -1671,7 +1684,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
dst_use_noref(&rt->dst, jiffies);
rt6_dst_from_metrics_check(rt);
}
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
return rt;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
@@ -1687,11 +1700,11 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
if (ip6_hold_safe(net, &rt, true)) {
dst_use_noref(&rt->dst, jiffies);
} else {
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
uncached_rt = rt;
goto uncached_rt_out;
}
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);
dst_release(&rt->dst);
@@ -1719,7 +1732,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
pcpu_rt = rt6_get_pcpu_route(rt);
if (pcpu_rt) {
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
} else {
/* atomic_inc_not_zero() is needed when using rcu */
if (atomic_inc_not_zero(&rt->rt6i_ref)) {
@@ -1730,12 +1743,12 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
* No dst_hold() on rt is needed because grabbing
* rt->rt6i_ref makes sure rt can't be released.
*/
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
pcpu_rt = rt6_make_pcpu_route(rt);
rt6_release(rt);
} else {
/* rt is already removed from tree */
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
pcpu_rt = net->ipv6.ip6_null_entry;
dst_hold(&pcpu_rt->dst);
}
@@ -2131,10 +2144,10 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
* routes.
*/
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
- for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_node_rt_rcu(fn) {
if (rt6_check_expired(rt))
continue;
if (rt->dst.error)
@@ -2179,7 +2192,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
out:
ip6_hold_safe(net, &rt, true);
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
return rt;
@@ -2778,9 +2791,9 @@ static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
}
table = rt->rt6i_table;
- write_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
err = fib6_del(rt, info);
- write_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
out:
ip6_rt_put(rt);
@@ -2806,7 +2819,7 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
if (rt == net->ipv6.ip6_null_entry)
goto out_put;
table = rt->rt6i_table;
- write_lock_bh(&table->tb6_lock);
+ spin_lock_bh(&table->tb6_lock);
if (rt->rt6i_nsiblings && cfg->fc_delete_all_nh) {
struct rt6_info *sibling, *next_sibling;
@@ -2836,7 +2849,7 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
err = fib6_del(rt, info);
out_unlock:
- write_unlock_bh(&table->tb6_lock);
+ spin_unlock_bh(&table->tb6_lock);
out_put:
ip6_rt_put(rt);
@@ -2861,7 +2874,7 @@ static int ip6_route_del(struct fib6_config *cfg,
return err;
}
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_locate(&table->tb6_root,
&cfg->fc_dst, cfg->fc_dst_len,
@@ -2869,7 +2882,7 @@ static int ip6_route_del(struct fib6_config *cfg,
!(cfg->fc_flags & RTF_CACHE));
if (fn) {
- for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_node_rt_rcu(fn) {
if (cfg->fc_flags & RTF_CACHE) {
rt_cache = rt6_find_cached_rt(rt, &cfg->fc_dst,
&cfg->fc_src);
@@ -2890,7 +2903,7 @@ static int ip6_route_del(struct fib6_config *cfg,
continue;
if (!dst_hold_safe(&rt->dst))
break;
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
/* if gateway was specified only delete the one hop */
if (cfg->fc_flags & RTF_GATEWAY)
@@ -2899,7 +2912,7 @@ static int ip6_route_del(struct fib6_config *cfg,
return __ip6_del_rt_siblings(rt, cfg);
}
}
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
return err;
}
@@ -3074,12 +3087,12 @@ static struct rt6_info *rt6_get_route_info(struct net *net,
if (!table)
return NULL;
- read_lock_bh(&table->tb6_lock);
+ rcu_read_lock();
fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
if (!fn)
goto out;
- for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
+ for_each_fib6_node_rt_rcu(fn) {
if (rt->dst.dev->ifindex != ifindex)
continue;
if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
@@ -3090,7 +3103,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net,
break;
}
out:
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
return rt;
}
@@ -3136,8 +3149,8 @@ struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_dev
if (!table)
return NULL;
- read_lock_bh(&table->tb6_lock);
- for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
+ rcu_read_lock();
+ for_each_fib6_node_rt_rcu(&table->tb6_root) {
if (dev == rt->dst.dev &&
((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
ipv6_addr_equal(&rt->rt6i_gateway, addr))
@@ -3145,7 +3158,7 @@ struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_dev
}
if (rt)
ip6_hold_safe(NULL, &rt, false);
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
return rt;
}
@@ -3183,20 +3196,20 @@ static void __rt6_purge_dflt_routers(struct fib6_table *table)
struct rt6_info *rt;
restart:
- read_lock_bh(&table->tb6_lock);
- for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
+ rcu_read_lock();
+ for_each_fib6_node_rt_rcu(&table->tb6_root) {
if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
(!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
if (dst_hold_safe(&rt->dst)) {
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
ip6_del_rt(rt);
} else {
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
}
goto restart;
}
}
- read_unlock_bh(&table->tb6_lock);
+ rcu_read_unlock();
table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
}