diff options
| -rw-r--r-- | include/linux/skbuff.h | 13 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 8 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 2 |
3 files changed, 18 insertions, 5 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 33370271b8b2..70a3f8d49118 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -481,6 +481,7 @@ struct sk_buff { union { __u32 mark; __u32 dropcount; + __u32 avail_size; }; sk_buff_data_t transport_header; @@ -1366,6 +1367,18 @@ static inline int skb_tailroom(const struct sk_buff *skb) } /** + * skb_availroom - bytes at buffer end + * @skb: buffer to check + * + * Return the number of bytes of free space at the tail of an sk_buff + * allocated by sk_stream_alloc() + */ +static inline int skb_availroom(const struct sk_buff *skb) +{ + return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len; +} + +/** * skb_reserve - adjust headroom * @skb: buffer to alter * @len: bytes to move diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 7758a83f98ff..a5daa211a8e1 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -701,11 +701,12 @@ struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp) skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp); if (skb) { if (sk_wmem_schedule(sk, skb->truesize)) { + skb_reserve(skb, sk->sk_prot->max_header); /* * Make sure that we have exactly size bytes * available to the caller, no more, no less. */ - skb_reserve(skb, skb_tailroom(skb) - size); + skb->avail_size = size; return skb; } __kfree_skb(skb); @@ -995,10 +996,9 @@ new_segment: copy = seglen; /* Where to copy to? */ - if (skb_tailroom(skb) > 0) { + if (skb_availroom(skb) > 0) { /* We have some space in skb head. Superb! */ - if (copy > skb_tailroom(skb)) - copy = skb_tailroom(skb); + copy = min_t(int, copy, skb_availroom(skb)); err = skb_add_data_nocache(sk, skb, from, copy); if (err) goto do_fault; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 364784a91939..376b2cfbb685 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2060,7 +2060,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, /* Punt if not enough space exists in the first SKB for * the data in the second */ - if (skb->len > skb_tailroom(to)) + if (skb->len > skb_availroom(to)) break; if (after(TCP_SKB_CB(skb)->end_seq, tcp_wnd_end(tp))) |