Commit 25121173 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller
Browse files

skb: api to report errors for zero copy skbs 



Orphaning frags for zero copy skbs needs to allocate data in atomic
context so is has a chance to fail. If it does we currently discard
the skb which is safe, but we don't report anything to the caller,
so it can not recover by e.g. disabling zero copy.

Add an API to free skb reporting such errors: this is used
by tun in case orphaning frags fails.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e19d6763

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -568,6 +568,7 @@ static inline struct rtable *skb_rtable(const struct sk_buff *skb) 
}



extern void kfree_skb(struct sk_buff *skb);

extern void skb_tx_error(struct sk_buff *skb);

extern void consume_skb(struct sk_buff *skb);

extern void	       __kfree_skb(struct sk_buff *skb);

extern struct kmem_cache *skbuff_head_cache;

net/core/skbuff.c

+20 −0
Original line number Diff line number Diff line
@@ -634,6 +634,26 @@ void kfree_skb(struct sk_buff *skb) 
}

EXPORT_SYMBOL(kfree_skb);



/**

 *	skb_tx_error - report an sk_buff xmit error

 *	@skb: buffer that triggered an error

 *

 *	Report xmit error if a device callback is tracking this skb.

 *	skb must be freed afterwards.

 */

void skb_tx_error(struct sk_buff *skb)

{

	if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {

		struct ubuf_info *uarg;



		uarg = skb_shinfo(skb)->destructor_arg;

		if (uarg->callback)

			uarg->callback(uarg, false);

		skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;

	}

}

EXPORT_SYMBOL(skb_tx_error);



/**

 *	consume_skb - free an skbuff

 *	@skb: buffer to free

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