netlink: Use rhashtable walk interface in diag dump
This patch converts the diag dumping code to use the rhashtable
walk code instead of going through rhashtable by hand. The lock
nl_table_lock is now only taken while we process the multicast
list as it's not needed for the rhashtable walk.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index 8dd836a..3e3e253 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -63,43 +63,75 @@
static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
int protocol, int s_num)
{
+ struct rhashtable_iter *hti = (void *)cb->args[2];
struct netlink_table *tbl = &nl_table[protocol];
- struct rhashtable *ht = &tbl->hash;
- const struct bucket_table *htbl = rht_dereference_rcu(ht->tbl, ht);
struct net *net = sock_net(skb->sk);
struct netlink_diag_req *req;
struct netlink_sock *nlsk;
struct sock *sk;
- int ret = 0, num = 0, i;
+ int num = 2;
+ int ret = 0;
req = nlmsg_data(cb->nlh);
- for (i = 0; i < htbl->size; i++) {
- struct rhash_head *pos;
+ if (s_num > 1)
+ goto mc_list;
- rht_for_each_entry_rcu(nlsk, pos, htbl, i, node) {
- sk = (struct sock *)nlsk;
+ num--;
- if (!net_eq(sock_net(sk), net))
- continue;
- if (num < s_num) {
- num++;
+ if (!hti) {
+ hti = kmalloc(sizeof(*hti), GFP_KERNEL);
+ if (!hti)
+ return -ENOMEM;
+
+ cb->args[2] = (long)hti;
+ }
+
+ if (!s_num)
+ rhashtable_walk_enter(&tbl->hash, hti);
+
+ ret = rhashtable_walk_start(hti);
+ if (ret == -EAGAIN)
+ ret = 0;
+ if (ret)
+ goto stop;
+
+ while ((nlsk = rhashtable_walk_next(hti))) {
+ if (IS_ERR(nlsk)) {
+ ret = PTR_ERR(nlsk);
+ if (ret == -EAGAIN) {
+ ret = 0;
continue;
}
+ break;
+ }
- if (sk_diag_fill(sk, skb, req,
- NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq,
- NLM_F_MULTI,
- sock_i_ino(sk)) < 0) {
- ret = 1;
- goto done;
- }
+ sk = (struct sock *)nlsk;
- num++;
+ if (!net_eq(sock_net(sk), net))
+ continue;
+
+ if (sk_diag_fill(sk, skb, req,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ NLM_F_MULTI,
+ sock_i_ino(sk)) < 0) {
+ ret = 1;
+ break;
}
}
+stop:
+ rhashtable_walk_stop(hti);
+ if (ret)
+ goto done;
+
+ rhashtable_walk_exit(hti);
+ cb->args[2] = 0;
+ num++;
+
+mc_list:
+ read_lock(&nl_table_lock);
sk_for_each_bound(sk, &tbl->mc_list) {
if (sk_hashed(sk))
continue;
@@ -116,13 +148,14 @@
NLM_F_MULTI,
sock_i_ino(sk)) < 0) {
ret = 1;
- goto done;
+ break;
}
num++;
}
+ read_unlock(&nl_table_lock);
+
done:
cb->args[0] = num;
- cb->args[1] = protocol;
return ret;
}
@@ -131,20 +164,20 @@
{
struct netlink_diag_req *req;
int s_num = cb->args[0];
+ int err = 0;
req = nlmsg_data(cb->nlh);
- rcu_read_lock();
- read_lock(&nl_table_lock);
-
if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
int i;
for (i = cb->args[1]; i < MAX_LINKS; i++) {
- if (__netlink_diag_dump(skb, cb, i, s_num))
+ err = __netlink_diag_dump(skb, cb, i, s_num);
+ if (err)
break;
s_num = 0;
}
+ cb->args[1] = i;
} else {
if (req->sdiag_protocol >= MAX_LINKS) {
read_unlock(&nl_table_lock);
@@ -152,13 +185,22 @@
return -ENOENT;
}
- __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
+ err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
}
- read_unlock(&nl_table_lock);
- rcu_read_unlock();
+ return err < 0 ? err : skb->len;
+}
- return skb->len;
+static int netlink_diag_dump_done(struct netlink_callback *cb)
+{
+ struct rhashtable_iter *hti = (void *)cb->args[2];
+
+ if (cb->args[0] == 1)
+ rhashtable_walk_exit(hti);
+
+ kfree(hti);
+
+ return 0;
}
static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
@@ -172,6 +214,7 @@
if (h->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = netlink_diag_dump,
+ .done = netlink_diag_dump_done,
};
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
} else