kcm: Sendpage support (f29698fc) · Commits · e / devices / android_kernel_fairphone_FP5

net/kcm/kcmsock.c

+145 −2

Original line number	Original line	Diff line number	Diff line
	@@ -990,6 +990,149 @@ static void kcm_push(struct kcm_sock *kcm)
	kcm_write_msgs(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)		static int kcm_sendmsg(struct socket sock, struct msghdr msg, size_t len)
	{		{
	struct sock *sk = sock->sk;		struct sock *sk = sock->sk;
	@@ -1995,7 +2138,7 @@ static const struct proto_ops kcm_dgram_ops = {
	.sendmsg = kcm_sendmsg,		.sendmsg = kcm_sendmsg,
	.recvmsg = kcm_recvmsg,		.recvmsg = kcm_recvmsg,
	.mmap = sock_no_mmap,		.mmap = sock_no_mmap,
	.sendpage = sock_no_sendpage,		.sendpage = kcm_sendpage,
	};		};

	static const struct proto_ops kcm_seqpacket_ops = {		static const struct proto_ops kcm_seqpacket_ops = {
	@@ -2016,7 +2159,7 @@ static const struct proto_ops kcm_seqpacket_ops = {
	.sendmsg = kcm_sendmsg,		.sendmsg = kcm_sendmsg,
	.recvmsg = kcm_recvmsg,		.recvmsg = kcm_recvmsg,
	.mmap = sock_no_mmap,		.mmap = sock_no_mmap,
	.sendpage = sock_no_sendpage,		.sendpage = kcm_sendpage,
	.splice_read = kcm_splice_read,		.splice_read = kcm_splice_read,
	};		};