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Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * released into the public domain | |
3 | * written by Mike Frysinger <vapier> | |
4 | */ | |
5 | ||
6 | #define _FILE_OFFSET_BITS 64 | |
7 | #define _LARGEFILE_SOURCE | |
8 | #define _LARGEFILE64_SOURCE | |
9 | #define _GNU_SOURCE | |
10 | ||
11 | #include <fcntl.h> | |
12 | #include <inttypes.h> | |
13 | #include <locale.h> | |
14 | #include <stdio.h> | |
15 | #include <stdlib.h> | |
16 | #include <string.h> | |
17 | #include <time.h> | |
18 | #include <unistd.h> | |
19 | ||
20 | static const char zero[1024 * 1024]; | |
21 | ||
22 | #define errp(msg, args...) \ | |
23 | do { \ | |
24 | printf("%s: " msg ": %m\n", argv[0], ## args); \ | |
25 | return 1; \ | |
26 | } while (0) | |
27 | ||
28 | static unsigned long long mbps(struct timespec *stime, struct timespec *etime, off_t len) | |
29 | { | |
30 | uint64_t dtime; | |
31 | clock_gettime(CLOCK_MONOTONIC, etime); | |
32 | dtime = ((etime->tv_sec - stime->tv_sec) * 1000 * 1000 * 1000) + | |
33 | (etime->tv_nsec - stime->tv_nsec); | |
34 | *stime = *etime; | |
35 | return 1000 * len / dtime; | |
36 | } | |
37 | ||
38 | int main(int argc, char *argv[]) | |
39 | { | |
40 | off_t offset = 0; | |
41 | const char *file; | |
42 | ||
43 | setlocale(LC_NUMERIC, "en_US"); | |
44 | ||
45 | switch (argc) { | |
46 | case 3: | |
47 | offset = atoll(argv[2]); | |
48 | case 2: | |
49 | file = argv[1]; | |
50 | break; | |
51 | default: | |
52 | puts("Usage: ddnuke <dev> [offset in bytes]"); | |
53 | return 1; | |
54 | } | |
55 | ||
56 | int fd = open(file, O_WRONLY); | |
57 | if (fd == -1) | |
58 | errp("open(%s) failed", file); | |
59 | ||
60 | if (lseek(fd, offset, SEEK_SET) != offset) | |
61 | errp("lseek(%"PRIu64"u) failed", offset); | |
62 | ||
63 | unsigned long long speed = 0; | |
64 | struct timespec stime, etime, itime; | |
65 | clock_gettime(CLOCK_MONOTONIC, &stime); | |
66 | itime = stime; | |
67 | ||
68 | off_t pos = 0, last_pos = 0; | |
69 | ssize_t ret; | |
70 | int fsync_pos = 0; | |
71 | while (1) { | |
72 | ret = write(fd, zero, sizeof(zero)); | |
73 | pos += ret; | |
74 | if (ret != sizeof(zero)) { | |
75 | printf("\ngot back %zi (wanted %zu)\n%'llu MB/s over entire run\n", | |
76 | ret, sizeof(zero), mbps(&itime, &etime, pos)); | |
77 | return 0; | |
78 | } | |
79 | ||
80 | printf("%'llu bytes (%'llu MB/s)%20s\r", (unsigned long long)pos, speed, ""); | |
81 | ||
82 | if ((++fsync_pos % 16) == 0) { | |
83 | speed = mbps(&stime, &etime, pos - last_pos); | |
84 | last_pos = pos; | |
85 | fflush(stdout); | |
86 | fsync(fd); | |
87 | } | |
88 | } | |
89 | ||
90 | return 0; | |
91 | } |