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7982a89851
Move it from tools/perf/util/cgroup.c as it can be used by other places. Note that cgroup filesystem is different from others since it's usually mounted separately (in v1) for each subsystem. I just copied the code with a little modification to pass a name of subsystem. Suggested-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lore.kernel.org/lkml/20200127100031.1368732-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
67 lines
1.4 KiB
C
67 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/stringify.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "fs.h"
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int cgroupfs_find_mountpoint(char *buf, size_t maxlen, const char *subsys)
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{
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FILE *fp;
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char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
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char path_v1[PATH_MAX + 1], path_v2[PATH_MAX + 2], *path;
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char *token, *saved_ptr = NULL;
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fp = fopen("/proc/mounts", "r");
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if (!fp)
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return -1;
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/*
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* in order to handle split hierarchy, we need to scan /proc/mounts
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* and inspect every cgroupfs mount point to find one that has
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* perf_event subsystem
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*/
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path_v1[0] = '\0';
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path_v2[0] = '\0';
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while (fscanf(fp, "%*s %"__stringify(PATH_MAX)"s %"__stringify(PATH_MAX)"s %"
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__stringify(PATH_MAX)"s %*d %*d\n",
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mountpoint, type, tokens) == 3) {
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if (!path_v1[0] && !strcmp(type, "cgroup")) {
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token = strtok_r(tokens, ",", &saved_ptr);
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while (token != NULL) {
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if (subsys && !strcmp(token, subsys)) {
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strcpy(path_v1, mountpoint);
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break;
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}
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token = strtok_r(NULL, ",", &saved_ptr);
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}
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}
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if (!path_v2[0] && !strcmp(type, "cgroup2"))
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strcpy(path_v2, mountpoint);
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if (path_v1[0] && path_v2[0])
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break;
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}
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fclose(fp);
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if (path_v1[0])
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path = path_v1;
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else if (path_v2[0])
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path = path_v2;
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else
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return -1;
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if (strlen(path) < maxlen) {
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strcpy(buf, path);
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return 0;
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}
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return -1;
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}
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