1 /* SPDX-License-Identifier: MIT */
2 /*
3 * Description: -EAGAIN handling
4 *
5 */
6 #include <errno.h>
7 #include <stdio.h>
8 #include <unistd.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <fcntl.h>
12
13 #include "helpers.h"
14 #include "liburing.h"
15
16 #define BLOCK 4096
17
18 #ifndef RWF_NOWAIT
19 #define RWF_NOWAIT 8
20 #endif
21
get_file_fd(void)22 static int get_file_fd(void)
23 {
24 ssize_t ret;
25 char *buf;
26 int fd;
27
28 fd = open("testfile", O_RDWR | O_CREAT, 0644);
29 if (fd < 0) {
30 perror("open file");
31 return -1;
32 }
33
34 buf = t_malloc(BLOCK);
35 ret = write(fd, buf, BLOCK);
36 if (ret != BLOCK) {
37 if (ret < 0)
38 perror("write");
39 else
40 printf("Short write\n");
41 goto err;
42 }
43 fsync(fd);
44
45 if (posix_fadvise(fd, 0, 4096, POSIX_FADV_DONTNEED)) {
46 perror("fadvise");
47 err:
48 close(fd);
49 free(buf);
50 return -1;
51 }
52
53 free(buf);
54 return fd;
55 }
56
put_file_fd(int fd)57 static void put_file_fd(int fd)
58 {
59 close(fd);
60 unlink("testfile");
61 }
62
main(int argc,char * argv[])63 int main(int argc, char *argv[])
64 {
65 struct io_uring ring;
66 struct io_uring_sqe *sqe;
67 struct io_uring_cqe *cqe;
68 struct iovec iov;
69 int ret, fd;
70
71 if (argc > 1)
72 return 0;
73
74 iov.iov_base = t_malloc(4096);
75 iov.iov_len = 4096;
76
77 ret = io_uring_queue_init(2, &ring, 0);
78 if (ret) {
79 printf("ring setup failed\n");
80 return 1;
81
82 }
83
84 sqe = io_uring_get_sqe(&ring);
85 if (!sqe) {
86 printf("get sqe failed\n");
87 return 1;
88 }
89
90 fd = get_file_fd();
91 if (fd < 0)
92 return 1;
93
94 io_uring_prep_readv(sqe, fd, &iov, 1, 0);
95 sqe->rw_flags = RWF_NOWAIT;
96
97 ret = io_uring_submit(&ring);
98 if (ret != 1) {
99 printf("Got submit %d, expected 1\n", ret);
100 goto err;
101 }
102
103 ret = io_uring_peek_cqe(&ring, &cqe);
104 if (ret) {
105 printf("Ring peek got %d\n", ret);
106 goto err;
107 }
108
109 if (cqe->res != -EAGAIN && cqe->res != 4096) {
110 printf("cqe error: %d\n", cqe->res);
111 goto err;
112 }
113
114 put_file_fd(fd);
115 return 0;
116 err:
117 put_file_fd(fd);
118 return 1;
119 }
120