Re: [PATCH net-next 2/3] net/smc: Limits backlog connections

[kernel test robot <lkp@intel.com>]

Hi Wythe",

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/D-Wythe/Optimizing-performance-in-short-lived/20220127-200912
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git fbb8295248e1d6f576d444309fcf79356008eac1
config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20220127/202201272349.KA4IX9hr-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/718aff24f3fcc73ecb7bff17fcbe029b799c6624
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review D-Wythe/Optimizing-performance-in-short-lived/20220127-200912
        git checkout 718aff24f3fcc73ecb7bff17fcbe029b799c6624
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arc SHELL=/bin/bash net/smc/

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

All warnings (new ones prefixed by >>):

   net/smc/af_smc.c: In function 'smc_listen':
>> net/smc/af_smc.c:2202:25: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    2202 |         smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
         |                         ^


vim +/const +2202 net/smc/af_smc.c

  2166	
  2167	static int smc_listen(struct socket *sock, int backlog)
  2168	{
  2169		struct sock *sk = sock->sk;
  2170		struct smc_sock *smc;
  2171		int rc;
  2172	
  2173		smc = smc_sk(sk);
  2174		lock_sock(sk);
  2175	
  2176		rc = -EINVAL;
  2177		if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
  2178		    smc->connect_nonblock)
  2179			goto out;
  2180	
  2181		rc = 0;
  2182		if (sk->sk_state == SMC_LISTEN) {
  2183			sk->sk_max_ack_backlog = backlog;
  2184			goto out;
  2185		}
  2186		/* some socket options are handled in core, so we could not apply
  2187		 * them to the clc socket -- copy smc socket options to clc socket
  2188		 */
  2189		smc_copy_sock_settings_to_clc(smc);
  2190		if (!smc->use_fallback)
  2191			tcp_sk(smc->clcsock->sk)->syn_smc = 1;
  2192	
  2193		/* save original sk_data_ready function and establish
  2194		 * smc-specific sk_data_ready function
  2195		 */
  2196		smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
  2197		smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
  2198		smc->clcsock->sk->sk_user_data =
  2199			(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
  2200	
  2201		/* save origin ops */
> 2202		smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
  2203	
  2204		smc->af_ops = *smc->ori_af_ops;
  2205		smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
  2206	
  2207		inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
  2208	
  2209		rc = kernel_listen(smc->clcsock, backlog);
  2210		if (rc) {
  2211			smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
  2212			goto out;
  2213		}
  2214		sk->sk_max_ack_backlog = backlog;
  2215		sk->sk_ack_backlog = 0;
  2216		sk->sk_state = SMC_LISTEN;
  2217	
  2218	out:
  2219		release_sock(sk);
  2220		return rc;
  2221	}
  2222	

---
0-DAY CI Kernel Test Service, Intel Corporation
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