1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2018 Intel Corporation. */
10 #include <sys/types.h>
14 #define PAGE(a) ((a)*0x1000)
17 void err_exit(char *op)
19 fprintf(stderr, "%s: %s\n", op, strerror(errno));
23 int main(int argc, char *argv[])
25 int fd, err, len = PAGE(1);
26 char *dax_data, *data;
30 printf("Usage: %s <file>\n", basename(argv[0]));
35 snprintf(string, STRLEN, "random number %d\n", rand());
37 fd = open(argv[1], O_RDWR);
41 data = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
42 if (data == MAP_FAILED)
43 err_exit("mmap data");
45 /* this fallocate turns off inline data and turns on DAX */
46 fallocate(fd, 0, 0, PAGE(2));
48 dax_data = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
49 if (dax_data == MAP_FAILED)
50 err_exit("mmap dax_data");
53 * Write the data using the non-DAX mapping, and try and read it back
54 * using the DAX mapping.
57 if (strcmp(dax_data, string) != 0)
58 printf("Data miscompare\n");
60 err = munmap(dax_data, len);
62 err_exit("munmap dax_data");
64 err = munmap(data, len);
66 err_exit("munmap data");