From 3d9953a2ef2182d56e268742259b11dedb8e281d Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 6 Aug 2013 17:45:08 +0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/core/datagram.c | 37 ++++++++++--------------------------- 1 file changed, 10 insertions(+), 27 deletions(-) diff --git a/net/core/datagram.c b/net/core/datagram.c index badcd93e5dd8..af814e764206 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -591,48 +591,31 @@ 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 copy = min_t(int, skb_headlen(skb), len); + int size; 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 (skb_copy_datagram_from_iovec(skb, 0, from, offset, copy)) + return -EFAULT; - if (len == offset1) + if (len == copy) return 0; + offset += copy; 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; + /* 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) -- 2.20.1