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net: use skb_copy_datagram_from_iovec() in zerocopy_sg_from_iovec() 

Use skb_copy_datagram_from_iovec() to avoid code duplication and make it easy to
be read. Also we can do the skipping inside the zero-copy loop.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2013-08-06 17:45:08 +08:00 committed by David S. Miller
parent 0433547aa7
commit 3d9953a2ef
1 changed files with 10 additions and 27 deletions
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37
net/core/datagram.c
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@ -591,48 +591,31 @@ int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
int offset, size_t count) int offset, size_t count)
{ {
int len = iov_length(from, count) - offset; int len = iov_length(from, count) - offset;
int copy = skb_headlen(skb); int copy = min_t(int, skb_headlen(skb), len);
int size, offset1 = 0; int size;
int i = 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 */ /* copy up to skb headlen */
while (count && (copy > 0)) { if (skb_copy_datagram_from_iovec(skb, 0, from, offset, copy))
size = min_t(unsigned int, copy, from->iov_len - offset); return -EFAULT;
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) if (len == copy)
return 0; return 0;
offset += copy;
while (count--) { while (count--) {
struct page *page[MAX_SKB_FRAGS]; struct page *page[MAX_SKB_FRAGS];
int num_pages; int num_pages;
unsigned long base; unsigned long base;
unsigned long truesize; unsigned long truesize;
len = from->iov_len - offset; /* Skip over from offset and copied */
if (!len) { if (offset >= from->iov_len) {
offset = 0; offset -= from->iov_len;
++from; ++from;
continue; continue;
} }
len = from->iov_len - offset;
base = (unsigned long)from->iov_base + offset; base = (unsigned long)from->iov_base + offset;
size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
if (i + size > MAX_SKB_FRAGS) if (i + size > MAX_SKB_FRAGS)