blob: 48c6902e749f7d78bf1d8a8b0a85fa4711565221 [file] [log] [blame]
Jiri Olsae90fda02012-01-27 15:34:22 +01001
2#include "util.h"
3#include "sysfs.h"
4
5static const char * const sysfs_known_mountpoints[] = {
6 "/sys",
7 0,
8};
9
10static int sysfs_found;
11char sysfs_mountpoint[PATH_MAX];
12
13static int sysfs_valid_mountpoint(const char *sysfs)
14{
15 struct statfs st_fs;
16
17 if (statfs(sysfs, &st_fs) < 0)
18 return -ENOENT;
19 else if (st_fs.f_type != (long) SYSFS_MAGIC)
20 return -ENOENT;
21
22 return 0;
23}
24
25const char *sysfs_find_mountpoint(void)
26{
27 const char * const *ptr;
28 char type[100];
29 FILE *fp;
30
31 if (sysfs_found)
32 return (const char *) sysfs_mountpoint;
33
34 ptr = sysfs_known_mountpoints;
35 while (*ptr) {
36 if (sysfs_valid_mountpoint(*ptr) == 0) {
37 sysfs_found = 1;
38 strcpy(sysfs_mountpoint, *ptr);
39 return sysfs_mountpoint;
40 }
41 ptr++;
42 }
43
44 /* give up and parse /proc/mounts */
45 fp = fopen("/proc/mounts", "r");
46 if (fp == NULL)
47 return NULL;
48
49 while (!sysfs_found &&
50 fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
51 sysfs_mountpoint, type) == 2) {
52
53 if (strcmp(type, "sysfs") == 0)
54 sysfs_found = 1;
55 }
56
57 fclose(fp);
58
59 return sysfs_found ? sysfs_mountpoint : NULL;
60}