nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

skbuff: allow 'slow_gro' for skb carring sock reference

Browse source 
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2021-07-28 18:24:03 +02:00 committed by David S. Miller
parent 9efb4b5baf
commit 5e10da5385
3 changed files with 24 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
include/net/sock.h
View file

@ -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);

2
net/core/dev.c
View file

@ -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;

17
net/core/skbuff.c
View file

@ -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;