net: Use __skb_pagelen() directly in skb_cow_data()

In fact, skb_pagelen() - skb_headlen() is equal to __skb_pagelen(), use it
directly to avoid unnecessary skb_headlen() call.

Also fix the CHECK note of checkpatch.pl:
    Comparison to NULL could be written "!__pskb_pull_tail"

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Miaohe Lin 2020-08-01 17:30:23 +08:00 committed by David S. Miller
parent 8340303670
commit c15fc199b3

View File

@ -4413,7 +4413,7 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
* at the moment even if they are anonymous).
*/
if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
__pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
!__pskb_pull_tail(skb, __skb_pagelen(skb)))
return -ENOMEM;
/* Easy case. Most of packets will go this way. */