Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759671Ab2J2Pra (ORCPT ); Mon, 29 Oct 2012 11:47:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3578 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753743Ab2J2Pr2 (ORCPT ); Mon, 29 Oct 2012 11:47:28 -0400 Date: Mon, 29 Oct 2012 17:49:41 +0200 From: "Michael S. Tsirkin" Cc: "Michael S. Tsirkin" , "David S. Miller" , Eric Dumazet , Andrew Morton , Alexander Duyck , Ian Campbell , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next 2/8] skb: api to report errors for zero copy skbs Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mutt-Fcc: =sent To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2050 Lines: 64 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 --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 8bac11b..0644432 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, int err); 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 eb31f6e..ad99c64 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -635,6 +635,25 @@ void kfree_skb(struct sk_buff *skb) EXPORT_SYMBOL(kfree_skb); /** + * kfree_skb_on_error - report an sk_buff xmit error + * @skb: buffer that triggered an error + * + * Report xmit error if a device callback is tracking this skb. + */ +void skb_tx_error(struct sk_buff *skb, int err) +{ + 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, err); + skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY; + } +} +EXPORT_SYMBOL(skb_tx_error); + +/** * consume_skb - free an skbuff * @skb: buffer to free * -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/