net: Add skb_unclone() helper function.
This function will be used in next GRE_GSO patch. This patch does
not change any functionality.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 0b2706a..4fd754e 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1805,8 +1805,7 @@
/* the filter instructions are constructed assuming
a four-byte PPP header on each packet */
if (ppp->pass_filter || ppp->active_filter) {
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
goto err;
*skb_push(skb, 2) = 0;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 9da9952..ca6ee7d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -804,6 +804,16 @@
(atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
}
+static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
+{
+ might_sleep_if(pri & __GFP_WAIT);
+
+ if (skb_cloned(skb))
+ return pskb_expand_head(skb, 0, 0, pri);
+
+ return 0;
+}
+
/**
* skb_header_cloned - is the header a clone
* @skb: buffer to check
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index a69b4e4..2e7f194 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -321,8 +321,7 @@
/* We are going to _remove_ AH header to keep sockets happy,
* so... Later this can change. */
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
goto out;
skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 1211613..b6d30ac 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -590,7 +590,7 @@
goto out_oversize;
/* Head of list must not be cloned. */
- if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(head, GFP_ATOMIC))
goto out_nomem;
/* If the first fragment is fragmented itself, we split
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 6182d90..fd0cea1 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1331,7 +1331,7 @@
/* Remove acked data from a packet in the transmit queue. */
int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
{
- if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
return -ENOMEM;
__pskb_trim_head(skb, len);
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 06814b6..1f12c8b 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -132,7 +132,7 @@
* header and optional ESP marker bytes) and then modify the
* protocol to ESP, and then call into the transform receiver.
*/
- if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
goto drop;
/* Now we can update and verify the packet length... */
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index ddee0a0..1162ace 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -142,8 +142,7 @@
for_each_input_rcu(rcv_notify_handlers, handler)
handler->handler(skb);
- if (skb_cloned(skb) &&
- (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+ if (err = skb_unclone(skb, GFP_ATOMIC))
goto out;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 3842331..bb02e17 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -521,8 +521,7 @@
/* We are going to _remove_ AH header to keep sockets happy,
* so... Later this can change. */
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
goto out;
skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index c674f15..b89a8c3 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -368,7 +368,7 @@
}
/* Head of list must not be cloned. */
- if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
+ if (skb_unclone(head, GFP_ATOMIC)) {
pr_debug("skb is cloned but can't expand head");
goto out_oom;
}
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index bab2c27..e354743 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -404,7 +404,7 @@
goto out_oversize;
/* Head of list must not be cloned. */
- if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(head, GFP_ATOMIC))
goto out_oom;
/* If the first fragment is fragmented itself, we split
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 9f2095b..93c41a8 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -69,8 +69,7 @@
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
- if (skb_cloned(skb) &&
- (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+ if (err = skb_unclone(skb, GFP_ATOMIC))
goto out;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index 0fb9e3f..e0f6de6 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -207,10 +207,8 @@
struct tcf_ipt *ipt = a->priv;
struct xt_action_param par;
- if (skb_cloned(skb)) {
- if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
- return TC_ACT_UNSPEC;
- }
+ if (skb_unclone(skb, GFP_ATOMIC))
+ return TC_ACT_UNSPEC;
spin_lock(&ipt->tcf_lock);
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 0c3fadd..7ed78c9 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -131,8 +131,7 @@
int i, munged = 0;
unsigned int off;
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(skb, GFP_ATOMIC))
return p->tcf_action;
off = skb_network_offset(skb);