net: add alloc_skb_with_frags() helper
Extract from sock_alloc_send_pskb() code building skb with frags,
so that we can reuse this in other contexts.
Intent is to use it from tcp_send_rcvq(), tcp_collapse(), ...
We also want to replace some skb_linearize() calls to a more reliable
strategy in pathological cases where we need to reduce number of frags.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sock.c b/net/core/sock.c
index 6f436b5..de887c4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1762,21 +1762,12 @@
unsigned long data_len, int noblock,
int *errcode, int max_page_order)
{
- struct sk_buff *skb = NULL;
- unsigned long chunk;
- gfp_t gfp_mask;
+ struct sk_buff *skb;
long timeo;
int err;
- int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
- struct page *page;
- int i;
-
- err = -EMSGSIZE;
- if (npages > MAX_SKB_FRAGS)
- goto failure;
timeo = sock_sndtimeo(sk, noblock);
- while (!skb) {
+ for (;;) {
err = sock_error(sk);
if (err != 0)
goto failure;
@@ -1785,66 +1776,27 @@
if (sk->sk_shutdown & SEND_SHUTDOWN)
goto failure;
- if (atomic_read(&sk->sk_wmem_alloc) >= sk->sk_sndbuf) {
- set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
- set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
- err = -EAGAIN;
- if (!timeo)
- goto failure;
- if (signal_pending(current))
- goto interrupted;
- timeo = sock_wait_for_wmem(sk, timeo);
- continue;
- }
+ if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
+ break;
- err = -ENOBUFS;
- gfp_mask = sk->sk_allocation;
- if (gfp_mask & __GFP_WAIT)
- gfp_mask |= __GFP_REPEAT;
-
- skb = alloc_skb(header_len, gfp_mask);
- if (!skb)
+ set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+ set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+ err = -EAGAIN;
+ if (!timeo)
goto failure;
-
- skb->truesize += data_len;
-
- for (i = 0; npages > 0; i++) {
- int order = max_page_order;
-
- while (order) {
- if (npages >= 1 << order) {
- page = alloc_pages(sk->sk_allocation |
- __GFP_COMP |
- __GFP_NOWARN |
- __GFP_NORETRY,
- order);
- if (page)
- goto fill_page;
- /* Do not retry other high order allocations */
- order = 1;
- max_page_order = 0;
- }
- order--;
- }
- page = alloc_page(sk->sk_allocation);
- if (!page)
- goto failure;
-fill_page:
- chunk = min_t(unsigned long, data_len,
- PAGE_SIZE << order);
- skb_fill_page_desc(skb, i, page, 0, chunk);
- data_len -= chunk;
- npages -= 1 << order;
- }
+ if (signal_pending(current))
+ goto interrupted;
+ timeo = sock_wait_for_wmem(sk, timeo);
}
-
- skb_set_owner_w(skb, sk);
+ skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
+ errcode, sk->sk_allocation);
+ if (skb)
+ skb_set_owner_w(skb, sk);
return skb;
interrupted:
err = sock_intr_errno(timeo);
failure:
- kfree_skb(skb);
*errcode = err;
return NULL;
}