macvtap: fix tx_dropped counting error

[mirror_ubuntu-bionic-kernel.git] / drivers / net / macvtap.c

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index ea53abb209889ed1032323bfcebd154e68fc1d1d..0605da8e25f5d992258a17e014010a8fe60f8adc 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -529,7 +529,7 @@ static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
                linear = len;
 
        skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
-                                  err);
+                                  err, 0);
        if (!skb)
                return NULL;
 
@@ -541,86 +541,6 @@ static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
        return skb;
 }
 
-/* set skb frags from iovec, this can move to core network code for reuse */
-static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
-                                 int offset, size_t count)
-{
-       int len = iov_length(from, count) - offset;
-       int copy = skb_headlen(skb);
-       int size, offset1 = 0;
-       int i = 0;
-
-       /* Skip over from offset */
-       while (count && (offset >= from->iov_len)) {
-               offset -= from->iov_len;
-               ++from;
-               --count;
-       }
-
-       /* copy up to skb headlen */
-       while (count && (copy > 0)) {
-               size = min_t(unsigned int, copy, from->iov_len - offset);
-               if (copy_from_user(skb->data + offset1, from->iov_base + offset,
-                                  size))
-                       return -EFAULT;
-               if (copy > size) {
-                       ++from;
-                       --count;
-                       offset = 0;
-               } else
-                       offset += size;
-               copy -= size;
-               offset1 += size;
-       }
-
-       if (len == offset1)
-               return 0;
-
-       while (count--) {
-               struct page *page[MAX_SKB_FRAGS];
-               int num_pages;
-               unsigned long base;
-               unsigned long truesize;
-
-               len = from->iov_len - offset;
-               if (!len) {
-                       offset = 0;
-                       ++from;
-                       continue;
-               }
-               base = (unsigned long)from->iov_base + offset;
-               size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
-               if (i + size > MAX_SKB_FRAGS)
-                       return -EMSGSIZE;
-               num_pages = get_user_pages_fast(base, size, 0, &page[i]);
-               if (num_pages != size) {
-                       int j;
-
-                       for (j = 0; j < num_pages; j++)
-                               put_page(page[i + j]);
-                       return -EFAULT;
-               }
-               truesize = size * PAGE_SIZE;
-               skb->data_len += len;
-               skb->len += len;
-               skb->truesize += truesize;
-               atomic_add(truesize, &skb->sk->sk_wmem_alloc);
-               while (len) {
-                       int off = base & ~PAGE_MASK;
-                       int size = min_t(int, len, PAGE_SIZE - off);
-                       __skb_fill_page_desc(skb, i, page[i], off, size);
-                       skb_shinfo(skb)->nr_frags++;
-                       /* increase sk_wmem_alloc */
-                       base += size;
-                       len -= size;
-                       i++;
-               }
-               offset = 0;
-               ++from;
-       }
-       return 0;
-}
-
 /*
  * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
  * be shared with the tun/tap driver.
@@ -703,34 +623,12 @@ static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
        return 0;
 }
 
-static unsigned long iov_pages(const struct iovec *iv, int offset,
-                              unsigned long nr_segs)
-{
-       unsigned long seg, base;
-       int pages = 0, len, size;
-
-       while (nr_segs && (offset >= iv->iov_len)) {
-               offset -= iv->iov_len;
-               ++iv;
-               --nr_segs;
-       }
-
-       for (seg = 0; seg < nr_segs; seg++) {
-               base = (unsigned long)iv[seg].iov_base + offset;
-               len = iv[seg].iov_len - offset;
-               size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
-               pages += size;
-               offset = 0;
-       }
-
-       return pages;
-}
-
 /* Get packet from user space buffer */
 static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
                                const struct iovec *iv, unsigned long total_len,
                                size_t count, int noblock)
 {
+       int good_linear = SKB_MAX_HEAD(NET_IP_ALIGN);
        struct sk_buff *skb;
        struct macvlan_dev *vlan;
        unsigned long len = total_len;
@@ -773,6 +671,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
        if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
                copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
+               if (copylen > good_linear)
+                       copylen = good_linear;
                linear = copylen;
                if (iov_pages(iv, vnet_hdr_len + copylen, count)
                    <= MAX_SKB_FRAGS)
@@ -781,7 +681,10 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
        if (!zerocopy) {
                copylen = len;
-               linear = vnet_hdr.hdr_len;
+               if (vnet_hdr.hdr_len > good_linear)
+                       linear = good_linear;
+               else
+                       linear = vnet_hdr.hdr_len;
        }
 
        skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
@@ -841,7 +744,7 @@ err:
        rcu_read_lock();
        vlan = rcu_dereference(q->vlan);
        if (vlan)
-               vlan->dev->stats.tx_dropped++;
+               this_cpu_inc(vlan->pcpu_stats->tx_dropped);
        rcu_read_unlock();
 
        return err;