diff options
author | Michael S. Tsirkin <mst@redhat.com> | 2013-12-26 13:32:47 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-15 23:31:37 (GMT) |
commit | 20d93869b19d03748b3f86d169ad830e2fbb7923 (patch) | |
tree | 0f4dd6175b26477a598fd4fd45a0b2b14470084b /drivers/net | |
parent | fd661199d7b4c16806f5bb1fcd76798559ba950e (diff) | |
download | linux-fsl-qoriq-20d93869b19d03748b3f86d169ad830e2fbb7923.tar.xz |
virtio_net: fix error handling for mergeable buffers
Eric Dumazet noticed that if we encounter an error
when processing a mergeable buffer, we don't
dequeue all of the buffers from this packet,
the result is almost sure to be loss of networking.
Fix this issue.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael Dalton <mwdalton@google.com>
Acked-by: Michael Dalton <mwdalton@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 8fc3b9e9a229778e5af3aa453c44f1a3857ba769)
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/virtio_net.c | 66 |
1 files changed, 46 insertions, 20 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index cded00b..52d8936 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -297,26 +297,33 @@ static struct sk_buff *page_to_skb(struct receive_queue *rq, return skb; } -static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) +static struct sk_buff *receive_mergeable(struct net_device *dev, + struct receive_queue *rq, + void *buf, + unsigned int len) { - struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); - struct page *page; - int num_buf, i, len; + struct skb_vnet_hdr *hdr = page_address(buf); + int num_buf = hdr->mhdr.num_buffers; + struct page *page = buf; + struct sk_buff *skb = page_to_skb(rq, page, len); + int i; + + if (unlikely(!skb)) + goto err_skb; - num_buf = hdr->mhdr.num_buffers; while (--num_buf) { i = skb_shinfo(skb)->nr_frags; if (i >= MAX_SKB_FRAGS) { pr_debug("%s: packet too long\n", skb->dev->name); skb->dev->stats.rx_length_errors++; - return -EINVAL; + return NULL; } page = virtqueue_get_buf(rq->vq, &len); if (!page) { - pr_debug("%s: rx error: %d buffers missing\n", - skb->dev->name, hdr->mhdr.num_buffers); - skb->dev->stats.rx_length_errors++; - return -EINVAL; + pr_debug("%s: rx error: %d buffers %d missing\n", + dev->name, hdr->mhdr.num_buffers, num_buf); + dev->stats.rx_length_errors++; + goto err_buf; } if (len > PAGE_SIZE) @@ -326,7 +333,25 @@ static int receive_mergeable(struct receive_queue *rq, struct sk_buff *skb) --rq->num; } - return 0; + return skb; +err_skb: + give_pages(rq, page); + while (--num_buf) { + buf = virtqueue_get_buf(rq->vq, &len); + if (unlikely(!buf)) { + pr_debug("%s: rx error: %d buffers missing\n", + dev->name, num_buf); + dev->stats.rx_length_errors++; + break; + } + page = buf; + give_pages(rq, page); + --rq->num; + } +err_buf: + dev->stats.rx_dropped++; + dev_kfree_skb(skb); + return NULL; } static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) @@ -354,17 +379,18 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) skb_trim(skb, len); } else { page = buf; - skb = page_to_skb(rq, page, len); - if (unlikely(!skb)) { - dev->stats.rx_dropped++; - give_pages(rq, page); - return; - } - if (vi->mergeable_rx_bufs) - if (receive_mergeable(rq, skb)) { - dev_kfree_skb(skb); + if (vi->mergeable_rx_bufs) { + skb = receive_mergeable(dev, rq, page, len); + if (unlikely(!skb)) + return; + } else { + skb = page_to_skb(rq, page, len); + if (unlikely(!skb)) { + dev->stats.rx_dropped++; + give_pages(rq, page); return; } + } } hdr = skb_vnet_hdr(skb); |