[PATCH net-next 5/6] skbuff: allow 'slow_gro' for skb carring sock reference
From: Paolo Abeni <pabeni@redhat.com>
Date: 2021-07-28 16:24:52
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
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 <pabeni@redhat.com> --- 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 8231cbddb6ed..9510cb0807bc 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);
@@ -3898,6 +3899,9 @@ 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;
@@ -4265,6 +4269,7 @@ 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))
@@ -4296,10 +4301,10 @@ 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;
@@ -4328,12 +4333,16 @@ 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;
--
2.26.3