From 25121173f7b1e4ac3fc692df6e7b8c52ec36abba Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 1 Nov 2012 09:16:28 +0000 Subject: [PATCH] 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: Michael S. Tsirkin Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index e5eae5bc1d4d..f2af494330ab 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -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; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4abdf71a23f8..d9addea10309 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -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 -- 2.20.1