perf tools: Add sysfs mountpoint interface

Adding sysfs object to provide sysfs mount information in the same way
as debugfs object does.

The object provides following function:
  sysfs_find_mountpoint

which returns the sysfs mount mount.

Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327674868-10486-4-git-send-email-jolsa@redhat.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2012-01-27 15:34:22 +01:00 committed by Arnaldo Carvalho de Melo
parent 2837609fef
commit e90fda0635
3 changed files with 68 additions and 0 deletions

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@ -259,6 +259,7 @@ LIB_H += util/callchain.h
LIB_H += util/build-id.h
LIB_H += util/debug.h
LIB_H += util/debugfs.h
LIB_H += util/sysfs.h
LIB_H += util/event.h
LIB_H += util/evsel.h
LIB_H += util/evlist.h
@ -305,6 +306,7 @@ LIB_OBJS += $(OUTPUT)util/build-id.o
LIB_OBJS += $(OUTPUT)util/config.o
LIB_OBJS += $(OUTPUT)util/ctype.o
LIB_OBJS += $(OUTPUT)util/debugfs.o
LIB_OBJS += $(OUTPUT)util/sysfs.o
LIB_OBJS += $(OUTPUT)util/environment.o
LIB_OBJS += $(OUTPUT)util/event.o
LIB_OBJS += $(OUTPUT)util/evlist.o

60
tools/perf/util/sysfs.c Normal file
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@ -0,0 +1,60 @@
#include "util.h"
#include "sysfs.h"
static const char * const sysfs_known_mountpoints[] = {
"/sys",
0,
};
static int sysfs_found;
char sysfs_mountpoint[PATH_MAX];
static int sysfs_valid_mountpoint(const char *sysfs)
{
struct statfs st_fs;
if (statfs(sysfs, &st_fs) < 0)
return -ENOENT;
else if (st_fs.f_type != (long) SYSFS_MAGIC)
return -ENOENT;
return 0;
}
const char *sysfs_find_mountpoint(void)
{
const char * const *ptr;
char type[100];
FILE *fp;
if (sysfs_found)
return (const char *) sysfs_mountpoint;
ptr = sysfs_known_mountpoints;
while (*ptr) {
if (sysfs_valid_mountpoint(*ptr) == 0) {
sysfs_found = 1;
strcpy(sysfs_mountpoint, *ptr);
return sysfs_mountpoint;
}
ptr++;
}
/* give up and parse /proc/mounts */
fp = fopen("/proc/mounts", "r");
if (fp == NULL)
return NULL;
while (!sysfs_found &&
fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
sysfs_mountpoint, type) == 2) {
if (strcmp(type, "sysfs") == 0)
sysfs_found = 1;
}
fclose(fp);
return sysfs_found ? sysfs_mountpoint : NULL;
}

6
tools/perf/util/sysfs.h Normal file
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@ -0,0 +1,6 @@
#ifndef __SYSFS_H__
#define __SYSFS_H__
const char *sysfs_find_mountpoint(void);
#endif /* __DEBUGFS_H__ */