On Sun, Jun 18, 2023 at 09:24:48AM +0300, Arseniy Krasnov wrote:
> This reworks current implementation of MSG_PEEK logic:
> 1) Replaces 'skb_queue_walk_safe()' with 'skb_queue_walk()'. There is
> no need in the first one, as there are no removes of skb in loop.
> 2) Removes nested while loop - MSG_PEEK logic could be implemented
> without it: just iterate over skbs without removing it and copy
> data from each until destination buffer is not full.
>
> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> ---
> net/vmw_vsock/virtio_transport_common.c | 41 ++++++++++++-------------
> 1 file changed, 19 insertions(+), 22 deletions(-)
>
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index b769fc258931..2ee40574c339 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -348,37 +348,34 @@ virtio_transport_stream_do_peek(struct vsock_sock *vsk,
> size_t len)
> {
> struct virtio_vsock_sock *vvs = vsk->trans;
> - size_t bytes, total = 0, off;
> - struct sk_buff *skb, *tmp;
> - int err = -EFAULT;
> + struct sk_buff *skb;
> + size_t total = 0;
> + int err;
>
> spin_lock_bh(&vvs->rx_lock);
>
> - skb_queue_walk_safe(&vvs->rx_queue, skb, tmp) {
> - off = 0;
> + skb_queue_walk(&vvs->rx_queue, skb) {
> + size_t bytes;
>
> - if (total == len)
> - break;
> + bytes = len - total;
> + if (bytes > skb->len)
> + bytes = skb->len;
>
> - while (total < len && off < skb->len) {
> - bytes = len - total;
> - if (bytes > skb->len - off)
> - bytes = skb->len - off;
> + spin_unlock_bh(&vvs->rx_lock);
>
> - /* 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);
> + /* sk_lock is held by caller so no one else can dequeue.
> + * Unlock rx_lock since memcpy_to_msg() may sleep.
> + */
> + err = memcpy_to_msg(msg, skb->data, bytes);
> + if (err)
> + goto out;
>
> - err = memcpy_to_msg(msg, skb->data + off, bytes);
> - if (err)
> - goto out;
> + total += bytes;
>
> - spin_lock_bh(&vvs->rx_lock);
> + spin_lock_bh(&vvs->rx_lock);
>
> - total += bytes;
> - off += bytes;
> - }
> + if (total == len)
> + break;
> }
>
> spin_unlock_bh(&vvs->rx_lock);
> --
> 2.25.1
>
That cleans up nicely!
LGTM.
Reviewed-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
