Hi Dmytro,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on v5.16]
[cannot apply to net-next/master linus/master next-20220116]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Dmytro-SHYTYI/net-mptcp-Fast-Open-Mechanism/20220116-081430
base:    df0cc57e057f18e44dac8e6c18aba47ab53202f9
config: i386-randconfig-a012 (https://download.01.org/0day-ci/archive/20220116/202201162159.uZep2msW-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/52c7bf82e2e91eb10c89ef6169fe02e0b63a6772
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Dmytro-SHYTYI/net-mptcp-Fast-Open-Mechanism/20220116-081430
        git checkout 52c7bf82e2e91eb10c89ef6169fe02e0b63a6772
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   net/mptcp/protocol.c: In function 'mptcp_sendmsg_fastopen':
>> net/mptcp/protocol.c:1650:8: error: implicit declaration of function 'sk_stream_alloc_skb'; did you mean 'tcp_stream_alloc_skb'? [-Werror=implicit-function-declaration]
    1650 |  skb = sk_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true);
         |        ^~~~~~~~~~~~~~~~~~~
         |        tcp_stream_alloc_skb
   net/mptcp/protocol.c:1650:6: warning: assignment to 'struct sk_buff *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
    1650 |  skb = sk_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true);
         |      ^
   cc1: some warnings being treated as errors


vim +1650 net/mptcp/protocol.c

  1635	
  1636	static int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
  1637					  size_t len, struct mptcp_sock *msk, size_t copied)
  1638	{
  1639		const struct iphdr *iph;
  1640		struct ubuf_info *uarg;
  1641		struct sockaddr *uaddr;
  1642		struct sk_buff *skb;
  1643		struct tcp_sock *tp;
  1644		struct socket *ssk;
  1645		int ret;
  1646	
  1647		ssk = __mptcp_nmpc_socket(msk);
  1648		if (unlikely(!ssk))
  1649			goto out_EFAULT;
> 1650		skb = sk_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true);
  1651		if (unlikely(!skb))
  1652			goto out_EFAULT;
  1653		iph = ip_hdr(skb);
  1654		if (unlikely(!iph))
  1655			goto out_EFAULT;
  1656		uarg = msg_zerocopy_realloc(sk, len, skb_zcopy(skb));
  1657		if (unlikely(!uarg))
  1658			goto out_EFAULT;
  1659		uaddr = msg->msg_name;
  1660	
  1661		tp = tcp_sk(ssk->sk);
  1662		if (unlikely(!tp))
  1663			goto out_EFAULT;
  1664		if (!tp->fastopen_req)
  1665			tp->fastopen_req = kzalloc(sizeof(*tp->fastopen_req), ssk->sk->sk_allocation);
  1666	
  1667		if (unlikely(!tp->fastopen_req))
  1668			goto out_EFAULT;
  1669		tp->fastopen_req->data = msg;
  1670		tp->fastopen_req->size = len;
  1671		tp->fastopen_req->uarg = uarg;
  1672	
  1673		/* requests a cookie */
  1674		ret = mptcp_stream_connect(sk->sk_socket, uaddr,
  1675					   msg->msg_namelen, msg->msg_flags);
  1676	
  1677		return ret;
  1678	out_EFAULT:
  1679		ret = -EFAULT;
  1680		return ret;
  1681	}
  1682	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org