提交 195e952d 编写于 作者: A Al Viro

kill zerocopy_sg_from_iovec()

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Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 f5ff53b4
......@@ -2661,8 +2661,6 @@ int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
int len);
int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
struct iov_iter *from, int len);
int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
int offset, size_t count);
int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
struct iov_iter *to, int size);
int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
......
......@@ -645,76 +645,15 @@ int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
EXPORT_SYMBOL(skb_copy_datagram_from_iter);
/**
* zerocopy_sg_from_iovec - Build a zerocopy datagram from an iovec
* zerocopy_sg_from_iter - Build a zerocopy datagram from an iov_iter
* @skb: buffer to copy
* @from: io vector to copy from
* @offset: offset in the io vector to start copying from
* @count: amount of vectors to copy to buffer from
* @from: the source to copy from
*
* The function will first copy up to headlen, and then pin the userspace
* pages and build frags through them.
*
* Returns 0, -EFAULT or -EMSGSIZE.
* Note: the iovec is not modified during the copy
*/
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 = min_t(int, skb_headlen(skb), len);
int size;
int i = 0;
/* copy up to skb headlen */
if (skb_copy_datagram_from_iovec(skb, 0, from, offset, copy))
return -EFAULT;
if (len == copy)
return 0;
offset += copy;
while (count--) {
struct page *page[MAX_SKB_FRAGS];
int num_pages;
unsigned long base;
unsigned long truesize;
/* Skip over from offset and copied */
if (offset >= from->iov_len) {
offset -= from->iov_len;
++from;
continue;
}
len = from->iov_len - offset;
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) {
release_pages(&page[i], num_pages, 0);
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);
base += size;
len -= size;
i++;
}
offset = 0;
++from;
}
return 0;
}
EXPORT_SYMBOL(zerocopy_sg_from_iovec);
int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from)
{
int len = iov_iter_count(from);
......
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