net: introduce netdev_alloc_frag()
Fix two issues introduced in commit a1c7fff7e18f5
( net: netdev_alloc_skb() use build_skb() )
- Must be IRQ safe (non NAPI drivers can use it)
- Must not leak the frag if build_skb() fails to allocate sk_buff
This patch introduces netdev_alloc_frag() for drivers willing to
use build_skb() instead of __netdev_alloc_skb() variants.
Factorize code so that :
__dev_alloc_skb() is a wrapper around __netdev_alloc_skb(), and
dev_alloc_skb() a wrapper around netdev_alloc_skb()
Use __GFP_COLD flag.
Almost all network drivers now benefit from skb->head_frag
infrastructure.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bb47314..fe37c21 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1680,31 +1680,11 @@
kfree_skb(skb);
}
-/**
- * __dev_alloc_skb - allocate an skbuff for receiving
- * @length: length to allocate
- * @gfp_mask: get_free_pages mask, passed to alloc_skb
- *
- * Allocate a new &sk_buff and assign it a usage count of one. The
- * buffer has unspecified headroom built in. Users should allocate
- * the headroom they think they need without accounting for the
- * built in space. The built in space is used for optimisations.
- *
- * %NULL is returned if there is no free memory.
- */
-static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
- gfp_t gfp_mask)
-{
- struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
- if (likely(skb))
- skb_reserve(skb, NET_SKB_PAD);
- return skb;
-}
-
-extern struct sk_buff *dev_alloc_skb(unsigned int length);
+extern void *netdev_alloc_frag(unsigned int fragsz);
extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
- unsigned int length, gfp_t gfp_mask);
+ unsigned int length,
+ gfp_t gfp_mask);
/**
* netdev_alloc_skb - allocate an skbuff for rx on a specific device
@@ -1720,11 +1700,25 @@
* allocates memory it can be called from an interrupt.
*/
static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
- unsigned int length)
+ unsigned int length)
{
return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
}
+/* legacy helper around __netdev_alloc_skb() */
+static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
+ gfp_t gfp_mask)
+{
+ return __netdev_alloc_skb(NULL, length, gfp_mask);
+}
+
+/* legacy helper around netdev_alloc_skb() */
+static inline struct sk_buff *dev_alloc_skb(unsigned int length)
+{
+ return netdev_alloc_skb(NULL, length);
+}
+
+
static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
unsigned int length, gfp_t gfp)
{