net: introduce netdev_alloc_frag()

Fix two issues introduced in commit a1c7fff7e1
( 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>
This commit is contained in:
Eric Dumazet
2012-05-18 05:12:12 +00:00
committed by David S. Miller
parent 56138f50d1
commit 6f532612cc
2 changed files with 59 additions and 65 deletions
+18 -24
View File
@@ -1680,31 +1680,11 @@ static inline void __skb_queue_purge(struct sk_buff_head *list)
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 @@ extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
* 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)
{