From 5e10da5385d20c4bae587bc2921e5fdd9655d5fc Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Wed, 28 Jul 2021 18:24:03 +0200 Subject: [PATCH] skbuff: allow 'slow_gro' for skb carring sock reference This change leverages the infrastructure introduced by the previous patches to allow soft devices passing to the GRO engine owned skbs without impacting the fast-path. It's up to the GRO caller ensuring the slow_gro bit validity before invoking the GRO engine. The new helper skb_prepare_for_gro() is introduced for that goal. On slow_gro, skbs are aggregated only with equal sk. Additionally, skb truesize on GRO recycle and free is correctly updated so that sk wmem is not changed by the GRO processing. rfc-> v1: - fixed bad truesize on dev_gro_receive NAPI_FREE - use the existing state bit Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- include/net/sock.h | 9 +++++++++ net/core/dev.c | 2 ++ net/core/skbuff.c | 17 +++++++++++++---- 3 files changed, 24 insertions(+), 4 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index f23cb259b0e2..ff1be7e7e90b 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2249,6 +2249,15 @@ static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struc return false; } +static inline void skb_prepare_for_gro(struct sk_buff *skb) +{ + if (skb->destructor != sock_wfree) { + skb_orphan(skb); + return; + } + skb->slow_gro = 1; +} + void sk_reset_timer(struct sock *sk, struct timer_list *timer, unsigned long expires); diff --git a/net/core/dev.c b/net/core/dev.c index 19565f7497ee..dcc87fcd64ba 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6034,6 +6034,7 @@ static void gro_list_prepare(const struct list_head *head, struct tc_skb_ext *p_ext; #endif + diffs |= p->sk != skb->sk; diffs |= skb_metadata_dst_cmp(p, skb); diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); @@ -6311,6 +6312,7 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) skb_shinfo(skb)->gso_type = 0; skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); if (unlikely(skb->slow_gro)) { + skb_orphan(skb); skb_ext_reset(skb); nf_reset_ct(skb); skb->slow_gro = 0; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d04e286149cc..fcbd977186b0 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -958,6 +958,7 @@ void napi_skb_free_stolen_head(struct sk_buff *skb) nf_reset_ct(skb); skb_dst_drop(skb); skb_ext_put(skb); + skb_orphan(skb); skb->slow_gro = 0; } napi_skb_cache_put(skb); @@ -3892,6 +3893,9 @@ int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) NAPI_GRO_CB(p)->last = skb; NAPI_GRO_CB(p)->count++; p->data_len += skb->len; + + /* sk owenrship - if any - completely transferred to the aggregated packet */ + skb->destructor = NULL; p->truesize += skb->truesize; p->len += skb->len; @@ -4259,6 +4263,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) unsigned int headlen = skb_headlen(skb); unsigned int len = skb_gro_len(skb); unsigned int delta_truesize; + unsigned int new_truesize; struct sk_buff *lp; if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush)) @@ -4290,10 +4295,10 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) skb_frag_size_sub(frag, offset); /* all fragments truesize : remove (head size + sk_buff) */ - delta_truesize = skb->truesize - - SKB_TRUESIZE(skb_end_offset(skb)); + new_truesize = SKB_TRUESIZE(skb_end_offset(skb)); + delta_truesize = skb->truesize - new_truesize; - skb->truesize -= skb->data_len; + skb->truesize = new_truesize; skb->len -= skb->data_len; skb->data_len = 0; @@ -4322,12 +4327,16 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); /* We dont need to clear skbinfo->nr_frags here */ - delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); + new_truesize = SKB_TRUESIZE(sizeof(struct sk_buff)); + delta_truesize = skb->truesize - new_truesize; + skb->truesize = new_truesize; NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; goto done; } merge: + /* sk owenrship - if any - completely transferred to the aggregated packet */ + skb->destructor = NULL; delta_truesize = skb->truesize; if (offset > headlen) { unsigned int eat = offset - headlen; -- 2.11.0