af_packet / TX_RING not fully non-blocking (w/ MSG_DONTWAIT).

This patch fixes an issue where the send(MSG_DONTWAIT) call
on a TX_RING is not fully non-blocking in cases where the device's sndBuf is
full. We pass nonblock=true to sock_alloc_send_skb() and return any possibly
occuring error code (most likely EGAIN) to the caller. As the fast-path stays
as it is, we keep the unlikely() around skb == NULL.

Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kretschmer, Mathias 2015-05-08 15:44:37 +02:00 коммит произвёл David S. Miller
Родитель cd9c399777
Коммит fbf33a2802
1 изменённых файлов: 6 добавлений и 3 удалений

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@ -2311,11 +2311,14 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
tlen = dev->needed_tailroom;
skb = sock_alloc_send_skb(&po->sk,
hlen + tlen + sizeof(struct sockaddr_ll),
0, &err);
!need_wait, &err);
if (unlikely(skb == NULL))
if (unlikely(skb == NULL)) {
/* we assume the socket was initially writeable ... */
if (likely(len_sum > 0))
err = len_sum;
goto out_status;
}
tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
addr, hlen);
if (tp_len > dev->mtu + dev->hard_header_len) {