tree 3042db7e451c61aefc60c1463bb6e307ca510638
parent d80d99d643090c3cf2b1f9fb3fadd1256f7e384f
author Herbert Xu <herbert@gondor.apana.org.au> 1125622139 -0700
committer David S. Miller <davem@davemloft.net> 1125622139 -0700

[TCP]: Fix sk_forward_alloc underflow in tcp_sendmsg

I've finally found a potential cause of the sk_forward_alloc underflows
that people have been reporting sporadically.

When tcp_sendmsg tacks on extra bits to an existing TCP_PAGE we don't
check sk_forward_alloc even though a large amount of time may have
elapsed since we allocated the page.  In the mean time someone could've
come along and liberated packets and reclaimed sk_forward_alloc memory.

This patch makes tcp_sendmsg check sk_forward_alloc every time as we
do in do_tcp_sendpages.
 
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>