Commit f29698fc authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller

kcm: Sendpage support

Implement kcm_sendpage. Set in sendpage to kcm_sendpage in both
dgram and seqpacket ops.
Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 91687355
......@@ -990,6 +990,149 @@ static void kcm_push(struct kcm_sock *kcm)
kcm_write_msgs(kcm);
}
static ssize_t kcm_sendpage(struct socket *sock, struct page *page,
int offset, size_t size, int flags)
{
struct sock *sk = sock->sk;
struct kcm_sock *kcm = kcm_sk(sk);
struct sk_buff *skb = NULL, *head = NULL;
long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
bool eor;
int err = 0;
int i;
if (flags & MSG_SENDPAGE_NOTLAST)
flags |= MSG_MORE;
/* No MSG_EOR from splice, only look at MSG_MORE */
eor = !(flags & MSG_MORE);
lock_sock(sk);
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
err = -EPIPE;
if (sk->sk_err)
goto out_error;
if (kcm->seq_skb) {
/* Previously opened message */
head = kcm->seq_skb;
skb = kcm_tx_msg(head)->last_skb;
i = skb_shinfo(skb)->nr_frags;
if (skb_can_coalesce(skb, i, page, offset)) {
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
goto coalesced;
}
if (i >= MAX_SKB_FRAGS) {
struct sk_buff *tskb;
tskb = alloc_skb(0, sk->sk_allocation);
while (!tskb) {
kcm_push(kcm);
err = sk_stream_wait_memory(sk, &timeo);
if (err)
goto out_error;
}
if (head == skb)
skb_shinfo(head)->frag_list = tskb;
else
skb->next = tskb;
skb = tskb;
skb->ip_summed = CHECKSUM_UNNECESSARY;
i = 0;
}
} else {
/* Call the sk_stream functions to manage the sndbuf mem. */
if (!sk_stream_memory_free(sk)) {
kcm_push(kcm);
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
err = sk_stream_wait_memory(sk, &timeo);
if (err)
goto out_error;
}
head = alloc_skb(0, sk->sk_allocation);
while (!head) {
kcm_push(kcm);
err = sk_stream_wait_memory(sk, &timeo);
if (err)
goto out_error;
}
skb = head;
i = 0;
}
get_page(page);
skb_fill_page_desc(skb, i, page, offset, size);
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
coalesced:
skb->len += size;
skb->data_len += size;
skb->truesize += size;
sk->sk_wmem_queued += size;
sk_mem_charge(sk, size);
if (head != skb) {
head->len += size;
head->data_len += size;
head->truesize += size;
}
if (eor) {
bool not_busy = skb_queue_empty(&sk->sk_write_queue);
/* Message complete, queue it on send buffer */
__skb_queue_tail(&sk->sk_write_queue, head);
kcm->seq_skb = NULL;
KCM_STATS_INCR(kcm->stats.tx_msgs);
if (flags & MSG_BATCH) {
kcm->tx_wait_more = true;
} else if (kcm->tx_wait_more || not_busy) {
err = kcm_write_msgs(kcm);
if (err < 0) {
/* We got a hard error in write_msgs but have
* already queued this message. Report an error
* in the socket, but don't affect return value
* from sendmsg
*/
pr_warn("KCM: Hard failure on kcm_write_msgs\n");
report_csk_error(&kcm->sk, -err);
}
}
} else {
/* Message not complete, save state */
kcm->seq_skb = head;
kcm_tx_msg(head)->last_skb = skb;
}
KCM_STATS_ADD(kcm->stats.tx_bytes, size);
release_sock(sk);
return size;
out_error:
kcm_push(kcm);
err = sk_stream_error(sk, flags, err);
/* make sure we wake any epoll edge trigger waiter */
if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
sk->sk_write_space(sk);
release_sock(sk);
return err;
}
static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
......@@ -1995,7 +2138,7 @@ static const struct proto_ops kcm_dgram_ops = {
.sendmsg = kcm_sendmsg,
.recvmsg = kcm_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
.sendpage = kcm_sendpage,
};
static const struct proto_ops kcm_seqpacket_ops = {
......@@ -2016,7 +2159,7 @@ static const struct proto_ops kcm_seqpacket_ops = {
.sendmsg = kcm_sendmsg,
.recvmsg = kcm_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
.sendpage = kcm_sendpage,
.splice_read = kcm_splice_read,
};
......
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