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Diffstat (limited to 'net/ipv4/fib_semantics.c')
-rw-r--r--net/ipv4/fib_semantics.c82
1 files changed, 43 insertions, 39 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 828de171708f..2dd375f7407b 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -29,6 +29,7 @@
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/netlink.h>
+#include <linux/hash.h>
#include <net/arp.h>
#include <net/ip.h>
@@ -51,6 +52,7 @@ static DEFINE_SPINLOCK(fib_info_lock);
static struct hlist_head *fib_info_hash;
static struct hlist_head *fib_info_laddrhash;
static unsigned int fib_info_hash_size;
+static unsigned int fib_info_hash_bits;
static unsigned int fib_info_cnt;
#define DEVINDEX_HASHBITS 8
@@ -249,7 +251,6 @@ void free_fib_info(struct fib_info *fi)
pr_warn("Freeing alive fib_info %p\n", fi);
return;
}
- fib_info_cnt--;
call_rcu(&fi->rcu, free_fib_info_rcu);
}
@@ -260,6 +261,10 @@ void fib_release_info(struct fib_info *fi)
spin_lock_bh(&fib_info_lock);
if (fi && refcount_dec_and_test(&fi->fib_treeref)) {
hlist_del(&fi->fib_hash);
+
+ /* Paired with READ_ONCE() in fib_create_info(). */
+ WRITE_ONCE(fib_info_cnt, fib_info_cnt - 1);
+
if (fi->fib_prefsrc)
hlist_del(&fi->fib_lhash);
if (fi->nh) {
@@ -316,11 +321,15 @@ static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
static inline unsigned int fib_devindex_hashfn(unsigned int val)
{
- unsigned int mask = DEVINDEX_HASHSIZE - 1;
+ return hash_32(val, DEVINDEX_HASHBITS);
+}
+
+static struct hlist_head *
+fib_info_devhash_bucket(const struct net_device *dev)
+{
+ u32 val = net_hash_mix(dev_net(dev)) ^ dev->ifindex;
- return (val ^
- (val >> DEVINDEX_HASHBITS) ^
- (val >> (DEVINDEX_HASHBITS * 2))) & mask;
+ return &fib_info_devhash[fib_devindex_hashfn(val)];
}
static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
@@ -430,12 +439,11 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev)
{
struct hlist_head *head;
struct fib_nh *nh;
- unsigned int hash;
spin_lock(&fib_info_lock);
- hash = fib_devindex_hashfn(dev->ifindex);
- head = &fib_info_devhash[hash];
+ head = fib_info_devhash_bucket(dev);
+
hlist_for_each_entry(nh, head, nh_hash) {
if (nh->fib_nh_dev == dev &&
nh->fib_nh_gw4 == gw &&
@@ -517,9 +525,9 @@ void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
fri.dst_len = dst_len;
fri.tos = fa->fa_tos;
fri.type = fa->fa_type;
- fri.offload = fa->offload;
- fri.trap = fa->trap;
- fri.offload_failed = fa->offload_failed;
+ fri.offload = READ_ONCE(fa->offload);
+ fri.trap = READ_ONCE(fa->trap);
+ fri.offload_failed = READ_ONCE(fa->offload_failed);
err = fib_dump_info(skb, info->portid, seq, event, &fri, nlm_flags);
if (err < 0) {
/* -EMSGSIZE implies BUG in fib_nlmsg_size() */
@@ -1240,13 +1248,13 @@ int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
return err;
}
-static inline unsigned int fib_laddr_hashfn(__be32 val)
+static struct hlist_head *
+fib_info_laddrhash_bucket(const struct net *net, __be32 val)
{
- unsigned int mask = (fib_info_hash_size - 1);
+ u32 slot = hash_32(net_hash_mix(net) ^ (__force u32)val,
+ fib_info_hash_bits);
- return ((__force u32)val ^
- ((__force u32)val >> 7) ^
- ((__force u32)val >> 14)) & mask;
+ return &fib_info_laddrhash[slot];
}
static struct hlist_head *fib_info_hash_alloc(int bytes)
@@ -1282,6 +1290,7 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
old_info_hash = fib_info_hash;
old_laddrhash = fib_info_laddrhash;
fib_info_hash_size = new_size;
+ fib_info_hash_bits = ilog2(new_size);
for (i = 0; i < old_size; i++) {
struct hlist_head *head = &fib_info_hash[i];
@@ -1299,21 +1308,20 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
}
fib_info_hash = new_info_hash;
+ fib_info_laddrhash = new_laddrhash;
for (i = 0; i < old_size; i++) {
- struct hlist_head *lhead = &fib_info_laddrhash[i];
+ struct hlist_head *lhead = &old_laddrhash[i];
struct hlist_node *n;
struct fib_info *fi;
hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) {
struct hlist_head *ldest;
- unsigned int new_hash;
- new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
- ldest = &new_laddrhash[new_hash];
+ ldest = fib_info_laddrhash_bucket(fi->fib_net,
+ fi->fib_prefsrc);
hlist_add_head(&fi->fib_lhash, ldest);
}
}
- fib_info_laddrhash = new_laddrhash;
spin_unlock_bh(&fib_info_lock);
@@ -1430,7 +1438,9 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
#endif
err = -ENOBUFS;
- if (fib_info_cnt >= fib_info_hash_size) {
+
+ /* Paired with WRITE_ONCE() in fib_release_info() */
+ if (READ_ONCE(fib_info_cnt) >= fib_info_hash_size) {
unsigned int new_size = fib_info_hash_size << 1;
struct hlist_head *new_info_hash;
struct hlist_head *new_laddrhash;
@@ -1462,7 +1472,6 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
return ERR_PTR(err);
}
- fib_info_cnt++;
fi->fib_net = net;
fi->fib_protocol = cfg->fc_protocol;
fi->fib_scope = cfg->fc_scope;
@@ -1591,12 +1600,13 @@ link_it:
refcount_set(&fi->fib_treeref, 1);
refcount_set(&fi->fib_clntref, 1);
spin_lock_bh(&fib_info_lock);
+ fib_info_cnt++;
hlist_add_head(&fi->fib_hash,
&fib_info_hash[fib_info_hashfn(fi)]);
if (fi->fib_prefsrc) {
struct hlist_head *head;
- head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
+ head = fib_info_laddrhash_bucket(net, fi->fib_prefsrc);
hlist_add_head(&fi->fib_lhash, head);
}
if (fi->nh) {
@@ -1604,12 +1614,10 @@ link_it:
} else {
change_nexthops(fi) {
struct hlist_head *head;
- unsigned int hash;
if (!nexthop_nh->fib_nh_dev)
continue;
- hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
- head = &fib_info_devhash[hash];
+ head = fib_info_devhash_bucket(nexthop_nh->fib_nh_dev);
hlist_add_head(&nexthop_nh->nh_hash, head);
} endfor_nexthops(fi)
}
@@ -1870,16 +1878,16 @@ nla_put_failure:
*/
int fib_sync_down_addr(struct net_device *dev, __be32 local)
{
- int ret = 0;
- unsigned int hash = fib_laddr_hashfn(local);
- struct hlist_head *head = &fib_info_laddrhash[hash];
int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
struct net *net = dev_net(dev);
+ struct hlist_head *head;
struct fib_info *fi;
+ int ret = 0;
if (!fib_info_laddrhash || local == 0)
return 0;
+ head = fib_info_laddrhash_bucket(net, local);
hlist_for_each_entry(fi, head, fib_lhash) {
if (!net_eq(fi->fib_net, net) ||
fi->fib_tb_id != tb_id)
@@ -1961,8 +1969,7 @@ void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
{
- unsigned int hash = fib_devindex_hashfn(dev->ifindex);
- struct hlist_head *head = &fib_info_devhash[hash];
+ struct hlist_head *head = fib_info_devhash_bucket(dev);
struct fib_nh *nh;
hlist_for_each_entry(nh, head, nh_hash) {
@@ -1981,12 +1988,11 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
*/
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
{
- int ret = 0;
- int scope = RT_SCOPE_NOWHERE;
+ struct hlist_head *head = fib_info_devhash_bucket(dev);
struct fib_info *prev_fi = NULL;
- unsigned int hash = fib_devindex_hashfn(dev->ifindex);
- struct hlist_head *head = &fib_info_devhash[hash];
+ int scope = RT_SCOPE_NOWHERE;
struct fib_nh *nh;
+ int ret = 0;
if (force)
scope = -1;
@@ -2131,7 +2137,6 @@ out:
int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
{
struct fib_info *prev_fi;
- unsigned int hash;
struct hlist_head *head;
struct fib_nh *nh;
int ret;
@@ -2147,8 +2152,7 @@ int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
}
prev_fi = NULL;
- hash = fib_devindex_hashfn(dev->ifindex);
- head = &fib_info_devhash[hash];
+ head = fib_info_devhash_bucket(dev);
ret = 0;
hlist_for_each_entry(nh, head, nh_hash) {
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