On 09/20/2018 11:12 AM, Dan Carpenter wrote: > Hi Ursula, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on net/master] > > url: https://github.com/0day-ci/linux/commits/Ursula-Braun/net-smc-fixes-2018-09-18/20180919-080857 > > smatch warnings: > net/smc/af_smc.c:1289 smc_listen_work() warn: inconsistent returns 'mutex:&smc_create_lgr_pending'. > Locked on: line 1285 > Unlocked on: line 1209 > > # https://github.com/0day-ci/linux/commit/c69342ef9becfe90f3778db1c386abdd80b786d1 > git remote add linux-review https://github.com/0day-ci/linux > git remote update linux-review > git checkout c69342ef9becfe90f3778db1c386abdd80b786d1 > vim +1289 net/smc/af_smc.c > > 3b2dec260 Hans Wippel 2018-05-18 1231 /* IPSec connections opt out of SMC-R optimizations */ > 3b2dec260 Hans Wippel 2018-05-18 1232 if (using_ipsec(new_smc)) { > 3b2dec260 Hans Wippel 2018-05-18 1233 smc_listen_decline(new_smc, SMC_CLC_DECL_IPSEC, 0); > 3b2dec260 Hans Wippel 2018-05-18 1234 return; > 3b2dec260 Hans Wippel 2018-05-18 1235 } > 3b2dec260 Hans Wippel 2018-05-18 1236 > 3b2dec260 Hans Wippel 2018-05-18 1237 mutex_lock(&smc_create_lgr_pending); > 3b2dec260 Hans Wippel 2018-05-18 1238 smc_close_init(new_smc); > 3b2dec260 Hans Wippel 2018-05-18 1239 smc_rx_init(new_smc); > 3b2dec260 Hans Wippel 2018-05-18 1240 smc_tx_init(new_smc); > 3b2dec260 Hans Wippel 2018-05-18 1241 > 413498440 Hans Wippel 2018-06-28 1242 /* check if ISM is available */ > 413498440 Hans Wippel 2018-06-28 1243 if ((pclc->hdr.path == SMC_TYPE_D || pclc->hdr.path == SMC_TYPE_B) && > 413498440 Hans Wippel 2018-06-28 1244 !smc_check_ism(new_smc, &ismdev) && > 413498440 Hans Wippel 2018-06-28 1245 !smc_listen_ism_init(new_smc, pclc, ismdev, &local_contact)) { > 413498440 Hans Wippel 2018-06-28 1246 ism_supported = true; > 413498440 Hans Wippel 2018-06-28 1247 } > 413498440 Hans Wippel 2018-06-28 1248 > 3b2dec260 Hans Wippel 2018-05-18 1249 /* check if RDMA is available */ > 413498440 Hans Wippel 2018-06-28 1250 if (!ism_supported && > 413498440 Hans Wippel 2018-06-28 1251 ((pclc->hdr.path != SMC_TYPE_R && pclc->hdr.path != SMC_TYPE_B) || > 7005ada68 Ursula Braun 2018-07-25 1252 smc_vlan_by_tcpsk(new_smc->clcsock, &vlan) || > 7005ada68 Ursula Braun 2018-07-25 1253 smc_check_rdma(new_smc, &ibdev, &ibport, vlan, NULL) || > 3b2dec260 Hans Wippel 2018-05-18 1254 smc_listen_rdma_check(new_smc, pclc) || > 3b2dec260 Hans Wippel 2018-05-18 1255 smc_listen_rdma_init(new_smc, pclc, ibdev, ibport, > 3b2dec260 Hans Wippel 2018-05-18 1256 &local_contact) || > 413498440 Hans Wippel 2018-06-28 1257 smc_listen_rdma_reg(new_smc, local_contact))) { > 3b2dec260 Hans Wippel 2018-05-18 1258 /* SMC not supported, decline */ > 145686baa Ursula Braun 2017-10-25 1259 mutex_unlock(&smc_create_lgr_pending); > 603cc1498 Karsten Graul 2018-07-25 1260 smc_listen_decline(new_smc, SMC_CLC_DECL_MODEUNSUPP, > 603cc1498 Karsten Graul 2018-07-25 1261 local_contact); > 3b2dec260 Hans Wippel 2018-05-18 1262 return; > a046d57da Ursula Braun 2017-01-09 1263 } > a046d57da Ursula Braun 2017-01-09 1264 > 3b2dec260 Hans Wippel 2018-05-18 1265 /* send SMC Accept CLC message */ > 3b2dec260 Hans Wippel 2018-05-18 1266 rc = smc_clc_send_accept(new_smc, local_contact); > 3b2dec260 Hans Wippel 2018-05-18 1267 if (rc) { > 145686baa Ursula Braun 2017-10-25 1268 mutex_unlock(&smc_create_lgr_pending); > 3b2dec260 Hans Wippel 2018-05-18 1269 smc_listen_decline(new_smc, rc, local_contact); > 3b2dec260 Hans Wippel 2018-05-18 1270 return; > 3b2dec260 Hans Wippel 2018-05-18 1271 } > 3b2dec260 Hans Wippel 2018-05-18 1272 > 3b2dec260 Hans Wippel 2018-05-18 1273 /* receive SMC Confirm CLC message */ > 3b2dec260 Hans Wippel 2018-05-18 1274 reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc), > 3b2dec260 Hans Wippel 2018-05-18 1275 SMC_CLC_CONFIRM); > 3b2dec260 Hans Wippel 2018-05-18 1276 if (reason_code) { > 3b2dec260 Hans Wippel 2018-05-18 1277 mutex_unlock(&smc_create_lgr_pending); > 3b2dec260 Hans Wippel 2018-05-18 1278 smc_listen_decline(new_smc, reason_code, local_contact); > 3b2dec260 Hans Wippel 2018-05-18 1279 return; > 3b2dec260 Hans Wippel 2018-05-18 1280 } > 3b2dec260 Hans Wippel 2018-05-18 1281 > 3b2dec260 Hans Wippel 2018-05-18 1282 /* finish worker */ > c69342ef9 Ursula Braun 2018-09-18 1283 if (!ism_supported) { > c69342ef9 Ursula Braun 2018-09-18 1284 if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) > c69342ef9 Ursula Braun 2018-09-18 1285 return; > ^^^^^^ > We need to mutex_unlock(&smc_create_lgr_pending); before the return. > The smatch warning is not necessary, since the mutex_unlock(&smc_create_lgr_pending) for this case is done within smc_listen_rdma_finish(). > c69342ef9 Ursula Braun 2018-09-18 1286 } > 3b2dec260 Hans Wippel 2018-05-18 1287 smc_conn_save_peer_info(new_smc, &cclc); > 3b2dec260 Hans Wippel 2018-05-18 1288 mutex_unlock(&smc_create_lgr_pending); > 3b2dec260 Hans Wippel 2018-05-18 @1289 smc_listen_out_connected(new_smc); > a046d57da Ursula Braun 2017-01-09 1290 } > a046d57da Ursula Braun 2017-01-09 1291 > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation > But you could argue the code confuses smatch and other readers. Thus I could improve readability with a patch like this: --- net/smc/af_smc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1184,7 +1184,6 @@ static int smc_listen_rdma_finish(struct return 0; decline: - mutex_unlock(&smc_create_lgr_pending); smc_listen_decline(new_smc, reason_code, local_contact); return reason_code; } @@ -1284,8 +1283,10 @@ static void smc_listen_work(struct work_ /* finish worker */ if (!ism_supported) { - if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) + if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) { + mutex_unlock(&smc_create_lgr_pending); return; + } } smc_conn_save_peer_info(new_smc, &cclc); mutex_unlock(&smc_create_lgr_pending); ---
