[PATCH NET 6/7] ax25: use pskb_realloc_headroom

From: Vasily Averin
Date: Mon Jul 12 2021 - 09:27:29 EST


Use pskb_realloc_headroom() in ax25_transmit_buffer and ax25_rt_build_path.
Unlike skb_realloc_headroom, new helper pskb_realloc_headroom
does not allocate a new skb if possible.

Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
---
net/ax25/ax25_out.c | 13 ++++---------
net/ax25/ax25_route.c | 13 ++++---------
2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/net/ax25/ax25_out.c b/net/ax25/ax25_out.c
index f53751b..1f1e581 100644
--- a/net/ax25/ax25_out.c
+++ b/net/ax25/ax25_out.c
@@ -336,18 +336,13 @@ void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type)

headroom = ax25_addr_size(ax25->digipeat);

- if (skb_headroom(skb) < headroom) {
- if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
+ if (unlikely(skb_headroom(skb) < headroom)) {
+ skb = pskb_realloc_head(roomskb, headroom);
+
+ if (!skb) {
printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
- kfree_skb(skb);
return;
}
-
- if (skb->sk != NULL)
- skb_set_owner_w(skbn, skb->sk);
-
- consume_skb(skb);
- skb = skbn;
}

ptr = skb_push(skb, headroom);
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index b40e0bc..8f54547 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -447,18 +447,13 @@ struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,

len = digi->ndigi * AX25_ADDR_LEN;

- if (skb_headroom(skb) < len) {
- if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
+ if (unlikely(skb_headroom(skb) < len)) {
+ skb = pskb_realloc_headroom(skb, len);
+
+ if (!skb) {
printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
return NULL;
}
-
- if (skb->sk != NULL)
- skb_set_owner_w(skbn, skb->sk);
-
- consume_skb(skb);
-
- skb = skbn;
}

bp = skb_push(skb, len);
--
1.8.3.1