[PATCH 3.12 080/111] skbuff: skb_segment: s/skb/head_skb/

From: Jiri Slaby
Date: Mon Jun 23 2014 - 04:57:51 EST


From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

[ Upstream commit df5771ffefb13f8af5392bd54fd7e2b596a3a357 ]

rename local variable to make it easier to tell at a glance that we are
dealing with a head skb.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/core/skbuff.c | 55 +++++++++++++++++++++++++++----------------------------
1 file changed, 27 insertions(+), 28 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 08381710ad82..2ab26d5668df 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2715,41 +2715,42 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum);

/**
* skb_segment - Perform protocol segmentation on skb.
- * @skb: buffer to segment
+ * @head_skb: buffer to segment
* @features: features for the output path (see dev->features)
*
* This function performs segmentation on the given skb. It returns
* a pointer to the first in a list of new skbs for the segments.
* In case of error it returns ERR_PTR(err).
*/
-struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
+struct sk_buff *skb_segment(struct sk_buff *head_skb,
+ netdev_features_t features)
{
struct sk_buff *segs = NULL;
struct sk_buff *tail = NULL;
- struct sk_buff *fskb = skb_shinfo(skb)->frag_list;
- skb_frag_t *frag = skb_shinfo(skb)->frags;
- unsigned int mss = skb_shinfo(skb)->gso_size;
- unsigned int doffset = skb->data - skb_mac_header(skb);
+ struct sk_buff *fskb = skb_shinfo(head_skb)->frag_list;
+ skb_frag_t *frag = skb_shinfo(head_skb)->frags;
+ unsigned int mss = skb_shinfo(head_skb)->gso_size;
+ unsigned int doffset = head_skb->data - skb_mac_header(head_skb);
unsigned int offset = doffset;
- unsigned int tnl_hlen = skb_tnl_header_len(skb);
+ unsigned int tnl_hlen = skb_tnl_header_len(head_skb);
unsigned int headroom;
unsigned int len;
__be16 proto;
bool csum;
int sg = !!(features & NETIF_F_SG);
- int nfrags = skb_shinfo(skb)->nr_frags;
+ int nfrags = skb_shinfo(head_skb)->nr_frags;
int err = -ENOMEM;
int i = 0;
int pos;

- proto = skb_network_protocol(skb);
+ proto = skb_network_protocol(head_skb);
if (unlikely(!proto))
return ERR_PTR(-EINVAL);

csum = !!can_checksum_protocol(features, proto);
- __skb_push(skb, doffset);
- headroom = skb_headroom(skb);
- pos = skb_headlen(skb);
+ __skb_push(head_skb, doffset);
+ headroom = skb_headroom(head_skb);
+ pos = skb_headlen(head_skb);

do {
struct sk_buff *nskb;
@@ -2757,11 +2758,11 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
int hsize;
int size;

- len = skb->len - offset;
+ len = head_skb->len - offset;
if (len > mss)
len = mss;

- hsize = skb_headlen(skb) - offset;
+ hsize = skb_headlen(head_skb) - offset;
if (hsize < 0)
hsize = 0;
if (hsize > len || !sg)
@@ -2810,7 +2811,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
__skb_push(nskb, doffset);
} else {
nskb = __alloc_skb(hsize + doffset + headroom,
- GFP_ATOMIC, skb_alloc_rx_flag(skb),
+ GFP_ATOMIC, skb_alloc_rx_flag(head_skb),
NUMA_NO_NODE);

if (unlikely(!nskb))
@@ -2826,19 +2827,19 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
segs = nskb;
tail = nskb;

- __copy_skb_header(nskb, skb);
- nskb->mac_len = skb->mac_len;
+ __copy_skb_header(nskb, head_skb);
+ nskb->mac_len = head_skb->mac_len;

/* nskb and skb might have different headroom */
if (nskb->ip_summed == CHECKSUM_PARTIAL)
nskb->csum_start += skb_headroom(nskb) - headroom;

skb_reset_mac_header(nskb);
- skb_set_network_header(nskb, skb->mac_len);
+ skb_set_network_header(nskb, head_skb->mac_len);
nskb->transport_header = (nskb->network_header +
- skb_network_header_len(skb));
+ skb_network_header_len(head_skb));

- skb_copy_from_linear_data_offset(skb, -tnl_hlen,
+ skb_copy_from_linear_data_offset(head_skb, -tnl_hlen,
nskb->data - tnl_hlen,
doffset + tnl_hlen);

@@ -2847,7 +2848,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)

if (!sg) {
nskb->ip_summed = CHECKSUM_NONE;
- nskb->csum = skb_copy_and_csum_bits(skb, offset,
+ nskb->csum = skb_copy_and_csum_bits(head_skb, offset,
skb_put(nskb, len),
len, 0);
continue;
@@ -2855,10 +2856,11 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)

nskb_frag = skb_shinfo(nskb)->frags;

- skb_copy_from_linear_data_offset(skb, offset,
+ skb_copy_from_linear_data_offset(head_skb, offset,
skb_put(nskb, hsize), hsize);

- skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+ skb_shinfo(nskb)->tx_flags = skb_shinfo(head_skb)->tx_flags &
+ SKBTX_SHARED_FRAG;

while (pos < offset + len) {
if (i >= nfrags) {
@@ -2915,15 +2917,12 @@ perform_csum_check:
nskb->len - doffset, 0);
nskb->ip_summed = CHECKSUM_NONE;
}
- } while ((offset += len) < skb->len);
+ } while ((offset += len) < head_skb->len);

return segs;

err:
- while ((skb = segs)) {
- segs = skb->next;
- kfree_skb(skb);
- }
+ kfree_skb_list(segs);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(skb_segment);
--
2.0.0

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