Stefano Garzarella
2023-Jul-25 15:39 UTC
[RFC PATCH v2 1/4] virtio/vsock: rework MSG_PEEK for SOCK_STREAM
On Wed, Jul 19, 2023 at 10:27:05PM +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 at sberdevices.ru> >Reviewed-by: Bobby Eshleman <bobby.eshleman at bytedance.com> >--- > net/vmw_vsock/virtio_transport_common.c | 41 ++++++++++++------------- > 1 file changed, 19 insertions(+), 22 deletions(-)Reviewed-by: Stefano Garzarella <sgarzare at redhat.com>> >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 >