diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 6fcbbbd12ceb..77ddf2de712f 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -550,6 +550,7 @@ static inline struct sk_buff *alloc_skb_fclone(unsigned int size, return __alloc_skb(size, priority, 1, NUMA_NO_NODE); } +extern void skb_recycle(struct sk_buff *skb); extern bool skb_recycle_check(struct sk_buff *skb, int skb_size); extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); @@ -2484,5 +2485,25 @@ static inline void skb_checksum_none_assert(struct sk_buff *skb) bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); +static inline bool skb_is_recycleable(struct sk_buff *skb, int skb_size) +{ + if (irqs_disabled()) + return false; + + if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) + return false; + + if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE) + return false; + + skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD); + if (skb_end_pointer(skb) - skb->head < skb_size) + return false; + + if (skb_shared(skb) || skb_cloned(skb)) + return false; + + return true; +} #endif /* __KERNEL__ */ #endif /* _LINUX_SKBUFF_H */ diff --git a/net/core/skbuff.c b/net/core/skbuff.c index ce357d986251..e27104039a39 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -484,6 +484,30 @@ void consume_skb(struct sk_buff *skb) } EXPORT_SYMBOL(consume_skb); +/** + * skb_recycle - clean up an skb for reuse + * @skb: buffer + * + * Recycles the skb to be reused as a receive buffer. This + * function does any necessary reference count dropping, and + * cleans up the skbuff as if it just came from __alloc_skb(). + */ +void skb_recycle(struct sk_buff *skb) +{ + struct skb_shared_info *shinfo; + + skb_release_head_state(skb); + + shinfo = skb_shinfo(skb); + memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); + atomic_set(&shinfo->dataref, 1); + + memset(skb, 0, offsetof(struct sk_buff, tail)); + skb->data = skb->head + NET_SKB_PAD; + skb_reset_tail_pointer(skb); +} +EXPORT_SYMBOL(skb_recycle); + /** * skb_recycle_check - check if skb can be reused for receive * @skb: buffer @@ -498,33 +522,10 @@ EXPORT_SYMBOL(consume_skb); */ bool skb_recycle_check(struct sk_buff *skb, int skb_size) { - struct skb_shared_info *shinfo; - - if (irqs_disabled()) + if (!skb_is_recycleable(skb, skb_size)) return false; - if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) - return false; - - if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE) - return false; - - skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD); - if (skb_end_pointer(skb) - skb->head < skb_size) - return false; - - if (skb_shared(skb) || skb_cloned(skb)) - return false; - - skb_release_head_state(skb); - - shinfo = skb_shinfo(skb); - memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); - atomic_set(&shinfo->dataref, 1); - - memset(skb, 0, offsetof(struct sk_buff, tail)); - skb->data = skb->head + NET_SKB_PAD; - skb_reset_tail_pointer(skb); + skb_recycle(skb); return true; }