Commit 654d1f8a authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

packet: less dev_put() calls

- packet_sendmsg_spkt() can use dev_get_by_name_rcu() to avoid touching device refcount.

- packet_getname_spkt() & packet_getname() can use dev_get_by_index_rcu() to
  avoid touching device refcount too.

tpacket_snd() & packet_snd() can not use RCU yet because they can sleep when
allocating skb.
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1178f66e
...@@ -437,7 +437,8 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, ...@@ -437,7 +437,8 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
*/ */
saddr->spkt_device[13] = 0; saddr->spkt_device[13] = 0;
dev = dev_get_by_name(sock_net(sk), saddr->spkt_device); rcu_read_lock();
dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
err = -ENODEV; err = -ENODEV;
if (dev == NULL) if (dev == NULL)
goto out_unlock; goto out_unlock;
...@@ -500,14 +501,13 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, ...@@ -500,14 +501,13 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
*/ */
dev_queue_xmit(skb); dev_queue_xmit(skb);
dev_put(dev); rcu_read_unlock();
return len; return len;
out_free: out_free:
kfree_skb(skb); kfree_skb(skb);
out_unlock: out_unlock:
if (dev) rcu_read_unlock();
dev_put(dev);
return err; return err;
} }
...@@ -1518,12 +1518,13 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, ...@@ -1518,12 +1518,13 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
return -EOPNOTSUPP; return -EOPNOTSUPP;
uaddr->sa_family = AF_PACKET; uaddr->sa_family = AF_PACKET;
dev = dev_get_by_index(sock_net(sk), pkt_sk(sk)->ifindex); rcu_read_lock();
if (dev) { dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
if (dev)
strlcpy(uaddr->sa_data, dev->name, 15); strlcpy(uaddr->sa_data, dev->name, 15);
dev_put(dev); else
} else
memset(uaddr->sa_data, 0, 14); memset(uaddr->sa_data, 0, 14);
rcu_read_unlock();
*uaddr_len = sizeof(*uaddr); *uaddr_len = sizeof(*uaddr);
return 0; return 0;
...@@ -1543,16 +1544,17 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr, ...@@ -1543,16 +1544,17 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
sll->sll_family = AF_PACKET; sll->sll_family = AF_PACKET;
sll->sll_ifindex = po->ifindex; sll->sll_ifindex = po->ifindex;
sll->sll_protocol = po->num; sll->sll_protocol = po->num;
dev = dev_get_by_index(sock_net(sk), po->ifindex); rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
if (dev) { if (dev) {
sll->sll_hatype = dev->type; sll->sll_hatype = dev->type;
sll->sll_halen = dev->addr_len; sll->sll_halen = dev->addr_len;
memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len); memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
dev_put(dev);
} else { } else {
sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
sll->sll_halen = 0; sll->sll_halen = 0;
} }
rcu_read_unlock();
*uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
return 0; return 0;
......
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