Return-path: Received: from mout.gmx.net ([212.227.17.22]:53176 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753594Ab3FLMk0 (ORCPT ); Wed, 12 Jun 2013 08:40:26 -0400 From: Dave Wiltshire To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, nsujir@broadcom.com, mchan@broadcom.com, rmody@brocade.com, jcliburn@gmail.com, chris.snook@gmail.com, jeffrey.t.kirsher@intel.com, bruce.w.allan@intel.com, alexander.h.duyck@intel.com, cooldavid@cooldavid.org, linux-driver@qlogic.com, linux-wimax@intel.com, wimax@linuxwimax.org, linux-wireless@vger.kernel.org, viro@zeniv.linux.org.uk, eparis@redhat.com, edumazet@google.com, dev@openvswitch.org, jhs@mojatatu.com, Dave Wiltshire Subject: [PATCH 3/3] skbuff: Added new helper function skb_cow_clone_head. Date: Wed, 12 Jun 2013 22:40:11 +1000 Message-Id: <1371040811-8319-2-git-send-email-david.wiltshire@gmx.com> (sfid-20130612_144039_802396_E890F2C6) In-Reply-To: <1371040811-8319-1-git-send-email-david.wiltshire@gmx.com> References: <1371030906-2396-1-git-send-email-david.wiltshire@gmx.com> <1371040811-8319-1-git-send-email-david.wiltshire@gmx.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: In a few different drivers there is a check of (skb_cloned && !skb_clone_writable) before then using pskb_expand_head to copy the skb if that is required. There are already some skb_cow_* functions for other conditions, so added this one and changed the call sites. Signed-off-by: Dave Wiltshire --- include/linux/skbuff.h | 14 ++++++++++++++ net/core/dev.c | 8 ++------ net/openvswitch/actions.c | 22 +++++++--------------- net/sched/act_csum.c | 8 ++------ net/sched/act_nat.c | 18 +++++------------- 5 files changed, 30 insertions(+), 40 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a7393ad..7d18541 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2154,6 +2154,20 @@ static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) } /** + * skb_cow_clone_head + * @skb: buffer to cow + * @len: length up to which to write + * + * This function is identical to skb_cow and sb_cow_head except that we + * replace the skb_cloned check by skb_cloned && !skb_clone_writable. + * + */ +static inline int skb_cow_clone_head(struct sk_buff *skb, unsigned int len) +{ + return __skb_cow(skb, 0, skb_cloned(skb) && !skb_clone_writable(skb, len)); +} + +/** * skb_padto - pad an skbuff up to a minimal size * @skb: buffer to pad * @len: minimal length diff --git a/net/core/dev.c b/net/core/dev.c index fa007db..1fb1cf5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2222,12 +2222,8 @@ int skb_checksum_help(struct sk_buff *skb) offset += skb->csum_offset; BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb)); - if (skb_cloned(skb) && - !skb_clone_writable(skb, offset + sizeof(__sum16))) { - ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC); - if (ret) - goto out; - } + if (skb_cow_clone_head(skb, offset + sizeof(__sum16))) + goto out; *(__sum16 *)(skb->data + offset) = csum_fold(csum); out_set_summed: diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index 894b6cb..3d3a9d0 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -38,21 +38,13 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, const struct nlattr *attr, int len, bool keep_skb); -static int make_writable(struct sk_buff *skb, int write_len) -{ - if (!skb_cloned(skb) || skb_clone_writable(skb, write_len)) - return 0; - - return pskb_expand_head(skb, 0, 0, GFP_ATOMIC); -} - /* remove VLAN header from packet and update csum accordingly. */ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci) { struct vlan_hdr *vhdr; int err; - err = make_writable(skb, VLAN_ETH_HLEN); + err = skb_cow_clone_head(skb, VLAN_ETH_HLEN); if (unlikely(err)) return err; @@ -126,7 +118,7 @@ static int set_eth_addr(struct sk_buff *skb, const struct ovs_key_ethernet *eth_key) { int err; - err = make_writable(skb, ETH_HLEN); + err = skb_cow_clone_head(skb, ETH_HLEN); if (unlikely(err)) return err; @@ -221,7 +213,7 @@ static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key) struct iphdr *nh; int err; - err = make_writable(skb, skb_network_offset(skb) + + err = skb_cow_clone_head(skb, skb_network_offset(skb) + sizeof(struct iphdr)); if (unlikely(err)) return err; @@ -250,7 +242,7 @@ static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key) __be32 *saddr; __be32 *daddr; - err = make_writable(skb, skb_network_offset(skb) + + err = skb_cow_clone_head(skb, skb_network_offset(skb) + sizeof(struct ipv6hdr)); if (unlikely(err)) return err; @@ -284,7 +276,7 @@ static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key) return 0; } -/* Must follow make_writable() since that can move the skb data. */ +/* Must follow skb_cow_clone_head() since that can move the skb data. */ static void set_tp_port(struct sk_buff *skb, __be16 *port, __be16 new_port, __sum16 *check) { @@ -313,7 +305,7 @@ static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key) struct udphdr *uh; int err; - err = make_writable(skb, skb_transport_offset(skb) + + err = skb_cow_clone_head(skb, skb_transport_offset(skb) + sizeof(struct udphdr)); if (unlikely(err)) return err; @@ -333,7 +325,7 @@ static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key) struct tcphdr *th; int err; - err = make_writable(skb, skb_transport_offset(skb) + + err = skb_cow_clone_head(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)); if (unlikely(err)) return err; diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c index 3a4c0ca..e7ff098 100644 --- a/net/sched/act_csum.c +++ b/net/sched/act_csum.c @@ -122,9 +122,7 @@ static void *tcf_csum_skb_nextlayer(struct sk_buff *skb, int hl = ihl + jhl; if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) || - (skb_cloned(skb) && - !skb_clone_writable(skb, hl + ntkoff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) + skb_cow_clone_head(skb, hl + ntkoff)) return NULL; else return (void *)(skb_network_header(skb) + ihl); @@ -382,9 +380,7 @@ static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags) } if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) { - if (skb_cloned(skb) && - !skb_clone_writable(skb, sizeof(*iph) + ntkoff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + if (skb_cow_clone_head(skb, sizeof(*iph) + ntkoff)) goto fail; ip_send_check(ip_hdr(skb)); diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c index 876f0ef..2b5b89c 100644 --- a/net/sched/act_nat.c +++ b/net/sched/act_nat.c @@ -144,9 +144,7 @@ static int tcf_nat(struct sk_buff *skb, const struct tc_action *a, addr = iph->daddr; if (!((old_addr ^ addr) & mask)) { - if (skb_cloned(skb) && - !skb_clone_writable(skb, sizeof(*iph) + noff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + if (skb_cow_clone_head(skb, sizeof(*iph) + noff)) goto drop; new_addr &= mask; @@ -174,9 +172,7 @@ static int tcf_nat(struct sk_buff *skb, const struct tc_action *a, struct tcphdr *tcph; if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) || - (skb_cloned(skb) && - !skb_clone_writable(skb, ihl + sizeof(*tcph) + noff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) + skb_cow_clone_head(skb, ihl + sizeof(*tcph) + noff)) goto drop; tcph = (void *)(skb_network_header(skb) + ihl); @@ -188,9 +184,7 @@ static int tcf_nat(struct sk_buff *skb, const struct tc_action *a, struct udphdr *udph; if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) || - (skb_cloned(skb) && - !skb_clone_writable(skb, ihl + sizeof(*udph) + noff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) + skb_cow_clone_head(skb, ihl + sizeof(*udph) + noff)) goto drop; udph = (void *)(skb_network_header(skb) + ihl); @@ -230,10 +224,8 @@ static int tcf_nat(struct sk_buff *skb, const struct tc_action *a, if ((old_addr ^ addr) & mask) break; - if (skb_cloned(skb) && - !skb_clone_writable(skb, ihl + sizeof(*icmph) + - sizeof(*iph) + noff) && - pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + if (skb_cow_clone_head(skb, ihl + sizeof(*icmph) + + sizeof(*iph) + noff)) goto drop; icmph = (void *)(skb_network_header(skb) + ihl); -- 1.7.10.4