diff options
author | Jean Delvare <jdelvare@suse.de> | 2007-04-26 07:44:22 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-04-26 07:44:22 (GMT) |
commit | eefa3906283a2b60a6d02a2cda593a7d7d7946c5 (patch) | |
tree | a4e1f3b8dca04b8dff3cd99dc43f771f798558fb /net/appletalk/ddp.c | |
parent | 28d8909bc790d936ce33f4402adf7577533bbd4b (diff) | |
download | linux-eefa3906283a2b60a6d02a2cda593a7d7d7946c5.tar.xz |
[NET]: Clean up sk_buff walkers.
I noticed recently that, in skb_checksum(), "offset" and "start" are
essentially the same thing and have the same value throughout the
function, despite being computed differently. Using a single variable
allows some cleanups and makes the skb_checksum() function smaller,
more readable, and presumably marginally faster.
We appear to have many other "sk_buff walker" functions built on the
exact same model, so the cleanup applies to them, too. Here is a list
of the functions I found to be affected:
net/appletalk/ddp.c:atalk_sum_skb()
net/core/datagram.c:skb_copy_datagram_iovec()
net/core/datagram.c:skb_copy_and_csum_datagram()
net/core/skbuff.c:skb_copy_bits()
net/core/skbuff.c:skb_store_bits()
net/core/skbuff.c:skb_checksum()
net/core/skbuff.c:skb_copy_and_csum_bit()
net/core/user_dma.c:dma_skb_copy_datagram_iovec()
net/xfrm/xfrm_algo.c:skb_icv_walk()
net/xfrm/xfrm_algo.c:skb_to_sgvec()
OTOH, I admit I'm a bit surprised, the cleanup is rather obvious so I'm
really wondering if I am missing something. Can anyone please comment
on this?
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/appletalk/ddp.c')
-rw-r--r-- | net/appletalk/ddp.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c index f6a92a0..16eda21 100644 --- a/net/appletalk/ddp.c +++ b/net/appletalk/ddp.c @@ -937,11 +937,11 @@ static unsigned long atalk_sum_partial(const unsigned char *data, static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset, int len, unsigned long sum) { - int start = skb_headlen(skb); + int end = skb_headlen(skb); int i, copy; /* checksum stuff in header space */ - if ( (copy = start - offset) > 0) { + if ((copy = end - offset) > 0) { if (copy > len) copy = len; sum = atalk_sum_partial(skb->data + offset, copy, sum); @@ -953,11 +953,9 @@ static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset, /* checksum stuff in frags */ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { - int end; + BUG_TRAP(len >= 0); - BUG_TRAP(start <= offset + len); - - end = start + skb_shinfo(skb)->frags[i].size; + end = offset + skb_shinfo(skb)->frags[i].size; if ((copy = end - offset) > 0) { u8 *vaddr; skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; @@ -965,36 +963,31 @@ static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset, if (copy > len) copy = len; vaddr = kmap_skb_frag(frag); - sum = atalk_sum_partial(vaddr + frag->page_offset + - offset - start, copy, sum); + sum = atalk_sum_partial(vaddr + frag->page_offset, + copy, sum); kunmap_skb_frag(vaddr); if (!(len -= copy)) return sum; offset += copy; } - start = end; } if (skb_shinfo(skb)->frag_list) { struct sk_buff *list = skb_shinfo(skb)->frag_list; for (; list; list = list->next) { - int end; - - BUG_TRAP(start <= offset + len); + BUG_TRAP(len >= 0); - end = start + list->len; + end = offset + list->len; if ((copy = end - offset) > 0) { if (copy > len) copy = len; - sum = atalk_sum_skb(list, offset - start, - copy, sum); + sum = atalk_sum_skb(list, 0, copy, sum); if ((len -= copy) == 0) return sum; offset += copy; } - start = end; } } |