linux/tools/lib/api/fs/findfs.c
Steven Rostedt (Red Hat) cde164aee9 tools lib fs: Add helper to find mounted file systems
In preparation for adding tracefs for perf to use, create a findfs
helper utility that find_debugfs uses instead of hard coding the search
in the code. This will allow for a find_tracefs to be used as well.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193552.735023362@goodmis.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-02-07 13:51:34 +01:00

64 lines
1.2 KiB
C

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <sys/vfs.h>
#include "findfs.h"
/* verify that a mountpoint is actually the type we want */
int valid_mountpoint(const char *mount, long magic)
{
struct statfs st_fs;
if (statfs(mount, &st_fs) < 0)
return -ENOENT;
else if ((long)st_fs.f_type != magic)
return -ENOENT;
return 0;
}
/* find the path to a mounted file system */
const char *find_mountpoint(const char *fstype, long magic,
char *mountpoint, int len,
const char * const *known_mountpoints)
{
const char * const *ptr;
char format[128];
char type[100];
FILE *fp;
if (known_mountpoints) {
ptr = known_mountpoints;
while (*ptr) {
if (valid_mountpoint(*ptr, magic) == 0) {
strncpy(mountpoint, *ptr, len - 1);
mountpoint[len-1] = 0;
return mountpoint;
}
ptr++;
}
}
/* give up and parse /proc/mounts */
fp = fopen("/proc/mounts", "r");
if (fp == NULL)
return NULL;
snprintf(format, 128, "%%*s %%%ds %%99s %%*s %%*d %%*d\n", len);
while (fscanf(fp, format, mountpoint, type) == 2) {
if (strcmp(type, fstype) == 0)
break;
}
fclose(fp);
if (strcmp(type, fstype) != 0)
return NULL;
return mountpoint;
}