7a3fb8b5c4
Move the cgroupfs_cache_entry 4128 byte array out of .bss. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Ross Zwisler <zwisler@chromium.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Yang Jihong <yangjihong1@huawei.com> Link: https://lore.kernel.org/r/20230526183401.2326121-15-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
107 lines
2.1 KiB
C
107 lines
2.1 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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struct cgroupfs_cache_entry {
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char subsys[32];
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char mountpoint[PATH_MAX];
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};
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/* just cache last used one */
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static struct cgroupfs_cache_entry *cached;
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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 *line = NULL;
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size_t len = 0;
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char *p, *path;
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char mountpoint[PATH_MAX];
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if (cached && !strcmp(cached->subsys, subsys)) {
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if (strlen(cached->mountpoint) < maxlen) {
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strcpy(buf, cached->mountpoint);
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return 0;
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}
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return -1;
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}
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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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* the given subsystem. If we found v1, just use it. If not we can
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* use v2 path as a fallback.
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*/
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mountpoint[0] = '\0';
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/*
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* The /proc/mounts has the follow format:
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*
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* <devname> <mount point> <fs type> <options> ...
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*
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*/
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while (getline(&line, &len, fp) != -1) {
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/* skip devname */
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p = strchr(line, ' ');
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if (p == NULL)
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continue;
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/* save the mount point */
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path = ++p;
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p = strchr(p, ' ');
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if (p == NULL)
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continue;
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*p++ = '\0';
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/* check filesystem type */
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if (strncmp(p, "cgroup", 6))
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continue;
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if (p[6] == '2') {
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/* save cgroup v2 path */
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strcpy(mountpoint, path);
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continue;
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}
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/* now we have cgroup v1, check the options for subsystem */
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p += 7;
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p = strstr(p, subsys);
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if (p == NULL)
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continue;
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/* sanity check: it should be separated by a space or a comma */
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if (!strchr(" ,", p[-1]) || !strchr(" ,", p[strlen(subsys)]))
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continue;
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strcpy(mountpoint, path);
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break;
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}
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free(line);
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fclose(fp);
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if (!cached)
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cached = calloc(1, sizeof(*cached));
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if (cached) {
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strncpy(cached->subsys, subsys, sizeof(cached->subsys) - 1);
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strcpy(cached->mountpoint, mountpoint);
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}
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if (mountpoint[0] && strlen(mountpoint) < maxlen) {
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strcpy(buf, mountpoint);
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return 0;
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}
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return -1;
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}
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