This is a note to let you know that I've just added the patch titled
virtio/vsock: don't use skbuff state to account credit
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio-vsock-don-t-use-skbuff-state-to-account-credit.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 077706165717686a2a6a71405fef036cd5b37ae0 Mon Sep 17 00:00:00 2001
From: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxx>
Date: Tue, 14 Mar 2023 14:05:48 +0300
Subject: virtio/vsock: don't use skbuff state to account credit
From: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxx>
commit 077706165717686a2a6a71405fef036cd5b37ae0 upstream.
'skb->len' can vary when we partially read the data, this complicates the
calculation of credit to be updated in 'virtio_transport_inc_rx_pkt()/
virtio_transport_dec_rx_pkt()'.
Also in 'virtio_transport_dec_rx_pkt()' we were miscalculating the
credit since 'skb->len' was redundant.
For these reasons, let's replace the use of skbuff state to calculate new
'rx_bytes'/'fwd_cnt' values with explicit value as input argument. This
makes code more simple, because it is not needed to change skbuff state
before each call to update 'rx_bytes'/'fwd_cnt'.
Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Acked-by: Bobby Eshleman <bobby.eshleman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/vmw_vsock/virtio_transport_common.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index a1581c77cf84..618680fd9906 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -241,21 +241,18 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
}
static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
- struct sk_buff *skb)
+ u32 len)
{
- if (vvs->rx_bytes + skb->len > vvs->buf_alloc)
+ if (vvs->rx_bytes + len > vvs->buf_alloc)
return false;
- vvs->rx_bytes += skb->len;
+ vvs->rx_bytes += len;
return true;
}
static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
- struct sk_buff *skb)
+ u32 len)
{
- int len;
-
- len = skb_headroom(skb) - sizeof(struct virtio_vsock_hdr) - skb->len;
vvs->rx_bytes -= len;
vvs->fwd_cnt += len;
}
@@ -388,7 +385,9 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
skb_pull(skb, bytes);
if (skb->len == 0) {
- virtio_transport_dec_rx_pkt(vvs, skb);
+ u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len);
+
+ virtio_transport_dec_rx_pkt(vvs, pkt_len);
consume_skb(skb);
} else {
__skb_queue_head(&vvs->rx_queue, skb);
@@ -437,17 +436,17 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
while (!msg_ready) {
struct virtio_vsock_hdr *hdr;
+ size_t pkt_len;
skb = __skb_dequeue(&vvs->rx_queue);
if (!skb)
break;
hdr = virtio_vsock_hdr(skb);
+ pkt_len = (size_t)le32_to_cpu(hdr->len);
if (dequeued_len >= 0) {
- size_t pkt_len;
size_t bytes_to_copy;
- pkt_len = (size_t)le32_to_cpu(hdr->len);
bytes_to_copy = min(user_buf_len, pkt_len);
if (bytes_to_copy) {
@@ -484,7 +483,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
msg->msg_flags |= MSG_EOR;
}
- virtio_transport_dec_rx_pkt(vvs, skb);
+ virtio_transport_dec_rx_pkt(vvs, pkt_len);
kfree_skb(skb);
}
@@ -1040,7 +1039,7 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
spin_lock_bh(&vvs->rx_lock);
- can_enqueue = virtio_transport_inc_rx_pkt(vvs, skb);
+ can_enqueue = virtio_transport_inc_rx_pkt(vvs, len);
if (!can_enqueue) {
free_pkt = true;
goto out;
--
2.42.1
Patches currently in stable-queue which might be from avkrasnov@xxxxxxxxxxxxxx are
queue-6.1/virtio-vsock-fix-header-length-on-skb-merging.patch
queue-6.1/virtio-vsock-don-t-drop-skbuff-on-copy-failure.patch
queue-6.1/virtio-vsock-don-t-use-skbuff-state-to-account-credit.patch
queue-6.1/virtio-vsock-remove-redundant-skb_pull-call.patch
