[isilence:zc_perf_tests 10/10] io_uring/net.c:1113 io_sendzc1() warn: ignoring unreachable code.

From: Dan Carpenter
Date: Tue Jul 26 2022 - 11:58:55 EST


tree: https://github.com/isilence/linux zc_perf_tests
head: 0909a53e1c81ca9432cbb58d15b87e500595bcbd
commit: 0909a53e1c81ca9432cbb58d15b87e500595bcbd [10/10] io_uring: simple zc
config: x86_64-randconfig-m001 (https://download.01.org/0day-ci/archive/20220726/202207261540.tELcS8V6-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
io_uring/net.c:1113 io_sendzc1() warn: ignoring unreachable code.

vim +1113 io_uring/net.c

0909a53e1c81ca Pavel Begunkov 2022-07-24 1087 int io_sendzc1(struct io_kiocb *req, unsigned int issue_flags)
0909a53e1c81ca Pavel Begunkov 2022-07-24 1088 {
0909a53e1c81ca Pavel Begunkov 2022-07-24 1089 struct io_sendzc1 *zc = io_kiocb_to_cmd(req);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1090 struct msghdr msg;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1091 struct iovec iov;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1092 struct socket *sock;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1093 unsigned msg_flags;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1094 int ret, min_ret = 0;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1095
0909a53e1c81ca Pavel Begunkov 2022-07-24 1096 sock = sock_from_file(req->file);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1097 if (unlikely(!sock))
0909a53e1c81ca Pavel Begunkov 2022-07-24 1098 return -ENOTSOCK;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1099
0909a53e1c81ca Pavel Begunkov 2022-07-24 1100 msg.msg_name = NULL;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1101 msg.msg_control = NULL;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1102 msg.msg_controllen = 0;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1103 msg.msg_namelen = 0;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1104
0909a53e1c81ca Pavel Begunkov 2022-07-24 1105 if (req->imu) {
0909a53e1c81ca Pavel Begunkov 2022-07-24 1106 ret = io_import_fixed(WRITE, &msg.msg_iter, req->imu,
0909a53e1c81ca Pavel Begunkov 2022-07-24 1107 (u64)(uintptr_t)zc->buf, zc->len);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1108 if (unlikely(ret))
0909a53e1c81ca Pavel Begunkov 2022-07-24 1109 return ret;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1110 } else {
0909a53e1c81ca Pavel Begunkov 2022-07-24 1111 return -EFAULT;
^^^^^^^^^^^^^^^

0909a53e1c81ca Pavel Begunkov 2022-07-24 1112
0909a53e1c81ca Pavel Begunkov 2022-07-24 @1113 ret = import_single_range(WRITE, zc->buf, zc->len, &iov,
0909a53e1c81ca Pavel Begunkov 2022-07-24 1114 &msg.msg_iter);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1115 if (unlikely(ret))
0909a53e1c81ca Pavel Begunkov 2022-07-24 1116 return ret;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1117 /* TODO: add pinning accounting */
0909a53e1c81ca Pavel Begunkov 2022-07-24 1118 }
0909a53e1c81ca Pavel Begunkov 2022-07-24 1119
0909a53e1c81ca Pavel Begunkov 2022-07-24 1120 msg_flags = zc->msg_flags | MSG_ZEROCOPY;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1121 if (issue_flags & IO_URING_F_NONBLOCK)
0909a53e1c81ca Pavel Begunkov 2022-07-24 1122 msg_flags |= MSG_DONTWAIT;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1123 if (msg_flags & MSG_WAITALL)
0909a53e1c81ca Pavel Begunkov 2022-07-24 1124 min_ret = iov_iter_count(&msg.msg_iter);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1125
0909a53e1c81ca Pavel Begunkov 2022-07-24 1126 msg.msg_flags = msg_flags;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1127 msg.msg_ubuf = &zc->ubuf;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1128 msg.sg_from_iter = io_sg_from_iter;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1129 ret = sock_sendmsg(sock, &msg);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1130
0909a53e1c81ca Pavel Begunkov 2022-07-24 1131 req->cqe.res = ret;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1132 if (refcount_dec_and_test(&zc->ubuf.refcnt)) {
0909a53e1c81ca Pavel Begunkov 2022-07-24 1133 io_req_set_res(req, req->cqe.res, 0);
0909a53e1c81ca Pavel Begunkov 2022-07-24 1134 return IOU_OK;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1135 }
0909a53e1c81ca Pavel Begunkov 2022-07-24 1136 return IOU_ISSUE_SKIP_COMPLETE;
0909a53e1c81ca Pavel Begunkov 2022-07-24 1137 }

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