From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: [PATCH net-next v3 07/13] sock: add ee_code SO_EE_CODE_ZEROCOPY_COPIED Date: Wed, 21 Jun 2017 17:18:10 -0400 Message-ID: <20170621211816.53837-8-willemdebruijn.kernel@gmail.com> References: <20170621211816.53837-1-willemdebruijn.kernel@gmail.com> Return-path: In-Reply-To: <20170621211816.53837-1-willemdebruijn.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-api@vger.kernel.org, Willem de Bruijn List-Id: linux-api@vger.kernel.org From: Willem de Bruijn A send request with MSG_ZEROCOPY falls back to copying when a request cannot be completed in zerocopy mode. Notify processes when the call reverted to copying through a new bit in the completion notification, so that they can optionally decline passing the flag on subsequent calls on the same path. Signed-off-by: Willem de Bruijn --- include/linux/skbuff.h | 2 ++ include/uapi/linux/errqueue.h | 2 ++ net/core/skbuff.c | 5 ++++- 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 554017a3aa3b..3b8c006b8592 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -416,6 +416,7 @@ struct ubuf_info { struct { u32 id; u16 len; + u16 zerocopy:1; u32 bytelen; }; }; @@ -1257,6 +1258,7 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy) struct ubuf_info *uarg = skb_zcopy(skb); if (uarg) { + uarg->zerocopy = uarg->zerocopy && zerocopy; sock_zerocopy_put(uarg); skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG; } diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index 0f15a77c9e39..78fdf52d6b2f 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -23,6 +23,8 @@ struct sock_extended_err { #define SO_EE_OFFENDER(ee) ((struct sockaddr*)((ee)+1)) +#define SO_EE_CODE_ZEROCOPY_COPIED 1 + /** * struct scm_timestamping - timestamps exposed through cmsg * diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 41fedc4e651f..35a7a7b1192f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -943,6 +943,7 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size) uarg->callback = sock_zerocopy_callback; uarg->id = ((u32)atomic_inc_return(&sk->sk_zckey)) - 1; uarg->len = 1; + uarg->zerocopy = 1; uarg->bytelen = size; atomic_set(&uarg->refcnt, 0); sock_hold(sk); @@ -1039,6 +1040,8 @@ void sock_zerocopy_callback(struct ubuf_info *uarg, bool success) serr->ee.ee_origin = SO_EE_ORIGIN_ZEROCOPY; serr->ee.ee_data = hi; serr->ee.ee_info = lo; + if (!success) + serr->ee.ee_code |= SO_EE_CODE_ZEROCOPY_COPIED; spin_lock_irqsave(&q->lock, flags); tail = skb_peek_tail(q); @@ -1061,7 +1064,7 @@ void sock_zerocopy_put(struct ubuf_info *uarg) { if (uarg && atomic_dec_and_test(&uarg->refcnt)) { if (uarg->callback) - uarg->callback(uarg, true); + uarg->callback(uarg, uarg->zerocopy); else consume_skb(skb_from_uarg(uarg)); } -- 2.13.1.611.g7e3b11ae1-goog