@@ -12,6 +12,7 @@
struct virtio_vsock_skb_cb {
bool reply;
bool tap_delivered;
+ u32 frag_off;
};
#define VIRTIO_VSOCK_SKB_CB(skb) ((struct virtio_vsock_skb_cb *)((skb)->cb))
@@ -355,7 +355,7 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk,
spin_lock_bh(&vvs->rx_lock);
skb_queue_walk_safe(&vvs->rx_queue, skb, tmp) {
- off = 0;
+ off = VIRTIO_VSOCK_SKB_CB(skb)->frag_off;
if (total == len)
break;
@@ -370,7 +370,10 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk,
*/
spin_unlock_bh(&vvs->rx_lock);
- err = memcpy_to_msg(msg, skb->data + off, bytes);
+ err = skb_copy_datagram_iter(skb, off,
+ &msg->msg_iter,
+ bytes);
+
if (err)
goto out;
@@ -411,27 +414,35 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
}
while (total < len && !skb_queue_empty(&vvs->rx_queue)) {
+ u32 skb_rest_len;
+
skb = skb_peek(&vvs->rx_queue);
bytes = len - total;
- if (bytes > skb->len)
- bytes = skb->len;
+ skb_rest_len = skb->len - VIRTIO_VSOCK_SKB_CB(skb)->frag_off;
+
+ if (bytes > skb_rest_len)
+ bytes = skb_rest_len;
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);
- err = memcpy_to_msg(msg, skb->data, bytes);
+ err = skb_copy_datagram_iter(skb,
+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off,
+ &msg->msg_iter, bytes);
+
if (err)
goto out;
spin_lock_bh(&vvs->rx_lock);
total += bytes;
- skb_pull(skb, bytes);
- if (skb->len == 0) {
+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off += bytes;
+
+ if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->frag_off) {
u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len);
virtio_transport_dec_rx_pkt(vvs, pkt_len);
@@ -503,7 +514,10 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
*/
spin_unlock_bh(&vvs->rx_lock);
- err = memcpy_to_msg(msg, skb->data, bytes_to_copy);
+ err = skb_copy_datagram_iter(skb, 0,
+ &msg->msg_iter,
+ bytes_to_copy);
+
if (err) {
/* Copy of message failed. Rest of
* fragments will be freed without copy.
This is preparation patch for non-linear skbuff handling. It replaces direct calls of 'memcpy_to_msg()' with 'skb_copy_datagram_iter()'. Main advantage of the second one is that is can handle paged part of the skb by using 'kmap()' on each page, but if there are no pages in the skb, it behaves like simple copying to iov iterator. This patch also adds new field to the control block of skb - this value shows current offset in the skb to read next portion of data (it doesn't matter linear it or not). Idea is that 'skb_copy_datagram_iter()' handles both types of skb internally - it just needs an offset from which to copy data from the given skb. This offset is incremented on each read from skb. This approach allows to avoid special handling of non-linear skbs: 1) We can't call 'skb_pull()' on it, because it updates 'data' pointer. 2) We need to update 'data_len' also on each read from this skb. Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> --- Changelog: v4 -> v5: * Use local variable for 'frag_off' in stream dequeue calback. * R-b from Bobby Eshleman removed due to patch update. include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport_common.c | 30 ++++++++++++++++++------- 2 files changed, 23 insertions(+), 8 deletions(-)