linux_dsm_epyc7002/tools/testing/selftests/cgroup/cgroup_util.c
Chris Down b59b1baab7 cgroup: kselftest: relax fs_spec checks
On my laptop most memcg kselftests were being skipped because it claimed
cgroup v2 hierarchy wasn't mounted, but this isn't correct.  Instead, it
seems current systemd HEAD mounts it with the name "cgroup2" instead of
"cgroup":

    % grep cgroup /proc/mounts
    cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate 0 0

I can't think of a reason to need to check fs_spec explicitly
since it's arbitrary, so we can just rely on fs_vfstype.

After these changes, `make TARGETS=cgroup kselftest` actually runs the
cgroup v2 tests in more cases.

Link: http://lkml.kernel.org/r/20190723210737.GA487@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-03 07:02:01 -07:00

421 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <linux/limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "cgroup_util.h"
static ssize_t read_text(const char *path, char *buf, size_t max_len)
{
ssize_t len;
int fd;
fd = open(path, O_RDONLY);
if (fd < 0)
return fd;
len = read(fd, buf, max_len - 1);
if (len < 0)
goto out;
buf[len] = 0;
out:
close(fd);
return len;
}
static ssize_t write_text(const char *path, char *buf, ssize_t len)
{
int fd;
fd = open(path, O_WRONLY | O_APPEND);
if (fd < 0)
return fd;
len = write(fd, buf, len);
if (len < 0) {
close(fd);
return len;
}
close(fd);
return len;
}
char *cg_name(const char *root, const char *name)
{
size_t len = strlen(root) + strlen(name) + 2;
char *ret = malloc(len);
snprintf(ret, len, "%s/%s", root, name);
return ret;
}
char *cg_name_indexed(const char *root, const char *name, int index)
{
size_t len = strlen(root) + strlen(name) + 10;
char *ret = malloc(len);
snprintf(ret, len, "%s/%s_%d", root, name, index);
return ret;
}
char *cg_control(const char *cgroup, const char *control)
{
size_t len = strlen(cgroup) + strlen(control) + 2;
char *ret = malloc(len);
snprintf(ret, len, "%s/%s", cgroup, control);
return ret;
}
int cg_read(const char *cgroup, const char *control, char *buf, size_t len)
{
char path[PATH_MAX];
snprintf(path, sizeof(path), "%s/%s", cgroup, control);
if (read_text(path, buf, len) >= 0)
return 0;
return -1;
}
int cg_read_strcmp(const char *cgroup, const char *control,
const char *expected)
{
size_t size;
char *buf;
int ret;
/* Handle the case of comparing against empty string */
if (!expected)
size = 32;
else
size = strlen(expected) + 1;
buf = malloc(size);
if (!buf)
return -1;
if (cg_read(cgroup, control, buf, size)) {
free(buf);
return -1;
}
ret = strcmp(expected, buf);
free(buf);
return ret;
}
int cg_read_strstr(const char *cgroup, const char *control, const char *needle)
{
char buf[PAGE_SIZE];
if (cg_read(cgroup, control, buf, sizeof(buf)))
return -1;
return strstr(buf, needle) ? 0 : -1;
}
long cg_read_long(const char *cgroup, const char *control)
{
char buf[128];
if (cg_read(cgroup, control, buf, sizeof(buf)))
return -1;
return atol(buf);
}
long cg_read_key_long(const char *cgroup, const char *control, const char *key)
{
char buf[PAGE_SIZE];
char *ptr;
if (cg_read(cgroup, control, buf, sizeof(buf)))
return -1;
ptr = strstr(buf, key);
if (!ptr)
return -1;
return atol(ptr + strlen(key));
}
int cg_write(const char *cgroup, const char *control, char *buf)
{
char path[PATH_MAX];
ssize_t len = strlen(buf);
snprintf(path, sizeof(path), "%s/%s", cgroup, control);
if (write_text(path, buf, len) == len)
return 0;
return -1;
}
int cg_find_unified_root(char *root, size_t len)
{
char buf[10 * PAGE_SIZE];
char *fs, *mount, *type;
const char delim[] = "\n\t ";
if (read_text("/proc/self/mounts", buf, sizeof(buf)) <= 0)
return -1;
/*
* Example:
* cgroup /sys/fs/cgroup cgroup2 rw,seclabel,noexec,relatime 0 0
*/
for (fs = strtok(buf, delim); fs; fs = strtok(NULL, delim)) {
mount = strtok(NULL, delim);
type = strtok(NULL, delim);
strtok(NULL, delim);
strtok(NULL, delim);
strtok(NULL, delim);
if (strcmp(type, "cgroup2") == 0) {
strncpy(root, mount, len);
return 0;
}
}
return -1;
}
int cg_create(const char *cgroup)
{
return mkdir(cgroup, 0644);
}
int cg_wait_for_proc_count(const char *cgroup, int count)
{
char buf[10 * PAGE_SIZE] = {0};
int attempts;
char *ptr;
for (attempts = 10; attempts >= 0; attempts--) {
int nr = 0;
if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf)))
break;
for (ptr = buf; *ptr; ptr++)
if (*ptr == '\n')
nr++;
if (nr >= count)
return 0;
usleep(100000);
}
return -1;
}
int cg_killall(const char *cgroup)
{
char buf[PAGE_SIZE];
char *ptr = buf;
if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf)))
return -1;
while (ptr < buf + sizeof(buf)) {
int pid = strtol(ptr, &ptr, 10);
if (pid == 0)
break;
if (*ptr)
ptr++;
else
break;
if (kill(pid, SIGKILL))
return -1;
}
return 0;
}
int cg_destroy(const char *cgroup)
{
int ret;
retry:
ret = rmdir(cgroup);
if (ret && errno == EBUSY) {
cg_killall(cgroup);
usleep(100);
goto retry;
}
if (ret && errno == ENOENT)
ret = 0;
return ret;
}
int cg_enter(const char *cgroup, int pid)
{
char pidbuf[64];
snprintf(pidbuf, sizeof(pidbuf), "%d", pid);
return cg_write(cgroup, "cgroup.procs", pidbuf);
}
int cg_enter_current(const char *cgroup)
{
char pidbuf[64];
snprintf(pidbuf, sizeof(pidbuf), "%d", getpid());
return cg_write(cgroup, "cgroup.procs", pidbuf);
}
int cg_run(const char *cgroup,
int (*fn)(const char *cgroup, void *arg),
void *arg)
{
int pid, retcode;
pid = fork();
if (pid < 0) {
return pid;
} else if (pid == 0) {
char buf[64];
snprintf(buf, sizeof(buf), "%d", getpid());
if (cg_write(cgroup, "cgroup.procs", buf))
exit(EXIT_FAILURE);
exit(fn(cgroup, arg));
} else {
waitpid(pid, &retcode, 0);
if (WIFEXITED(retcode))
return WEXITSTATUS(retcode);
else
return -1;
}
}
int cg_run_nowait(const char *cgroup,
int (*fn)(const char *cgroup, void *arg),
void *arg)
{
int pid;
pid = fork();
if (pid == 0) {
char buf[64];
snprintf(buf, sizeof(buf), "%d", getpid());
if (cg_write(cgroup, "cgroup.procs", buf))
exit(EXIT_FAILURE);
exit(fn(cgroup, arg));
}
return pid;
}
int get_temp_fd(void)
{
return open(".", O_TMPFILE | O_RDWR | O_EXCL);
}
int alloc_pagecache(int fd, size_t size)
{
char buf[PAGE_SIZE];
struct stat st;
int i;
if (fstat(fd, &st))
goto cleanup;
size += st.st_size;
if (ftruncate(fd, size))
goto cleanup;
for (i = 0; i < size; i += sizeof(buf))
read(fd, buf, sizeof(buf));
return 0;
cleanup:
return -1;
}
int alloc_anon(const char *cgroup, void *arg)
{
size_t size = (unsigned long)arg;
char *buf, *ptr;
buf = malloc(size);
for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
*ptr = 0;
free(buf);
return 0;
}
int is_swap_enabled(void)
{
char buf[PAGE_SIZE];
const char delim[] = "\n";
int cnt = 0;
char *line;
if (read_text("/proc/swaps", buf, sizeof(buf)) <= 0)
return -1;
for (line = strtok(buf, delim); line; line = strtok(NULL, delim))
cnt++;
return cnt > 1;
}
int set_oom_adj_score(int pid, int score)
{
char path[PATH_MAX];
int fd, len;
sprintf(path, "/proc/%d/oom_score_adj", pid);
fd = open(path, O_WRONLY | O_APPEND);
if (fd < 0)
return fd;
len = dprintf(fd, "%d", score);
if (len < 0) {
close(fd);
return len;
}
close(fd);
return 0;
}
char proc_read_text(int pid, const char *item, char *buf, size_t size)
{
char path[PATH_MAX];
snprintf(path, sizeof(path), "/proc/%d/%s", pid, item);
return read_text(path, buf, size);
}