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Systemd/src/basic/cgroup-util.c
Tejun Heo b6629c4b9f core: make SYSTEMD_CGROUP_CONTROLLER a special string 
SYSTEMD_CGROUP_CONTROLLER is currently defined as "name=systemd" which cgroup
utility functions interpret as a named cgroup hierarchy with the specified
named.  With the planned cgroup hybrid mode changes, SYSTEMD_CGROUP_CONTROLLER
would map to different hierarchy names.

This patch makes SYSTEMD_CGROUP_CONTROLLER a special string "_systemd" which is
substituted to "name=systemd" by the cgroup utility functions.  This allows the
callers to address the systemd hierarchy without actually specifying the
hierarchy name allowing the cgroup utility functions to map it to whatever is
appropriate.

Note that SYSTEMD_CGROUP_CONTROLLER was already special on full unified cgroup
hierarchy even before this patch.
2017-02-18 17:51:17 -05:00

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/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <dirent.h>
#include <errno.h>
#include <ftw.h>
#include <limits.h>
#include <signal.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <unistd.h>
#include "alloc-util.h"
#include "cgroup-util.h"
#include "def.h"
#include "dirent-util.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "fs-util.h"
#include "log.h"
#include "login-util.h"
#include "macro.h"
#include "missing.h"
#include "mkdir.h"
#include "parse-util.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "process-util.h"
#include "set.h"
#include "special.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "string-table.h"
#include "string-util.h"
#include "unit-name.h"
#include "user-util.h"
int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
_cleanup_free_ char *fs = NULL;
FILE *f;
int r;
assert(_f);
r = cg_get_path(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
f = fopen(fs, "re");
if (!f)
return -errno;
*_f = f;
return 0;
}
int cg_read_pid(FILE *f, pid_t *_pid) {
unsigned long ul;
/* Note that the cgroup.procs might contain duplicates! See
* cgroups.txt for details. */
assert(f);
assert(_pid);
errno = 0;
if (fscanf(f, "%lu", &ul) != 1) {
if (feof(f))
return 0;
return errno > 0 ? -errno : -EIO;
}
if (ul <= 0)
return -EIO;
*_pid = (pid_t) ul;
return 1;
}
int cg_read_event(const char *controller, const char *path, const char *event,
char **val)
{
_cleanup_free_ char *events = NULL, *content = NULL;
char *p, *line;
int r;
r = cg_get_path(controller, path, "cgroup.events", &events);
if (r < 0)
return r;
r = read_full_file(events, &content, NULL);
if (r < 0)
return r;
p = content;
while ((line = strsep(&p, "\n"))) {
char *key;
key = strsep(&line, " ");
if (!key || !line)
return -EINVAL;
if (strcmp(key, event))
continue;
*val = strdup(line);
return 0;
}
return -ENOENT;
}
bool cg_ns_supported(void) {
static thread_local int enabled = -1;
if (enabled >= 0)
return enabled;
if (access("/proc/self/ns/cgroup", F_OK) == 0)
enabled = 1;
else
enabled = 0;
return enabled;
}
int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
_cleanup_free_ char *fs = NULL;
int r;
DIR *d;
assert(_d);
/* This is not recursive! */
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
d = opendir(fs);
if (!d)
return -errno;
*_d = d;
return 0;
}
int cg_read_subgroup(DIR *d, char **fn) {
struct dirent *de;
assert(d);
assert(fn);
FOREACH_DIRENT_ALL(de, d, return -errno) {
char *b;
if (de->d_type != DT_DIR)
continue;
if (dot_or_dot_dot(de->d_name))
continue;
b = strdup(de->d_name);
if (!b)
return -ENOMEM;
*fn = b;
return 1;
}
return 0;
}
int cg_rmdir(const char *controller, const char *path) {
_cleanup_free_ char *p = NULL;
int r;
r = cg_get_path(controller, path, NULL, &p);
if (r < 0)
return r;
r = rmdir(p);
if (r < 0 && errno != ENOENT)
return -errno;
return 0;
}
int cg_kill(
const char *controller,
const char *path,
int sig,
CGroupFlags flags,
Set *s,
cg_kill_log_func_t log_kill,
void *userdata) {
_cleanup_set_free_ Set *allocated_set = NULL;
bool done = false;
int r, ret = 0;
pid_t my_pid;
assert(sig >= 0);
/* Don't send SIGCONT twice. Also, SIGKILL always works even when process is suspended, hence don't send
* SIGCONT on SIGKILL. */
if (IN_SET(sig, SIGCONT, SIGKILL))
flags &= ~CGROUP_SIGCONT;
/* This goes through the tasks list and kills them all. This
* is repeated until no further processes are added to the
* tasks list, to properly handle forking processes */
if (!s) {
s = allocated_set = set_new(NULL);
if (!s)
return -ENOMEM;
}
my_pid = getpid();
do {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0;
done = true;
r = cg_enumerate_processes(controller, path, &f);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_pid(f, &pid)) > 0) {
if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid)
continue;
if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid))
continue;
if (log_kill)
log_kill(pid, sig, userdata);
/* If we haven't killed this process yet, kill
* it */
if (kill(pid, sig) < 0) {
if (ret >= 0 && errno != ESRCH)
ret = -errno;
} else {
if (flags & CGROUP_SIGCONT)
(void) kill(pid, SIGCONT);
if (ret == 0)
ret = 1;
}
done = false;
r = set_put(s, PID_TO_PTR(pid));
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
}
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
/* To avoid racing against processes which fork
* quicker than we can kill them we repeat this until
* no new pids need to be killed. */
} while (!done);
return ret;
}
int cg_kill_recursive(
const char *controller,
const char *path,
int sig,
CGroupFlags flags,
Set *s,
cg_kill_log_func_t log_kill,
void *userdata) {
_cleanup_set_free_ Set *allocated_set = NULL;
_cleanup_closedir_ DIR *d = NULL;
int r, ret;
char *fn;
assert(path);
assert(sig >= 0);
if (!s) {
s = allocated_set = set_new(NULL);
if (!s)
return -ENOMEM;
}
ret = cg_kill(controller, path, sig, flags, s, log_kill, userdata);
r = cg_enumerate_subgroups(controller, path, &d);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(path, "/", fn);
free(fn);
if (!p)
return -ENOMEM;
r = cg_kill_recursive(controller, p, sig, flags, s, log_kill, userdata);
if (r != 0 && ret >= 0)
ret = r;
}
if (ret >= 0 && r < 0)
ret = r;
if (flags & CGROUP_REMOVE) {
r = cg_rmdir(controller, path);
if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
return r;
}
return ret;
}
int cg_migrate(
const char *cfrom,
const char *pfrom,
const char *cto,
const char *pto,
CGroupFlags flags) {
bool done = false;
_cleanup_set_free_ Set *s = NULL;
int r, ret = 0;
pid_t my_pid;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
s = set_new(NULL);
if (!s)
return -ENOMEM;
my_pid = getpid();
do {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0;
done = true;
r = cg_enumerate_processes(cfrom, pfrom, &f);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_pid(f, &pid)) > 0) {
/* This might do weird stuff if we aren't a
* single-threaded program. However, we
* luckily know we are not */
if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid)
continue;
if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid))
continue;
/* Ignore kernel threads. Since they can only
* exist in the root cgroup, we only check for
* them there. */
if (cfrom &&
(isempty(pfrom) || path_equal(pfrom, "/")) &&
is_kernel_thread(pid) > 0)
continue;
r = cg_attach(cto, pto, pid);
if (r < 0) {
if (ret >= 0 && r != -ESRCH)
ret = r;
} else if (ret == 0)
ret = 1;
done = false;
r = set_put(s, PID_TO_PTR(pid));
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
}
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
} while (!done);
return ret;
}
int cg_migrate_recursive(
const char *cfrom,
const char *pfrom,
const char *cto,
const char *pto,
CGroupFlags flags) {
_cleanup_closedir_ DIR *d = NULL;
int r, ret = 0;
char *fn;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
ret = cg_migrate(cfrom, pfrom, cto, pto, flags);
r = cg_enumerate_subgroups(cfrom, pfrom, &d);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(pfrom, "/", fn);
free(fn);
if (!p)
return -ENOMEM;
r = cg_migrate_recursive(cfrom, p, cto, pto, flags);
if (r != 0 && ret >= 0)
ret = r;
}
if (r < 0 && ret >= 0)
ret = r;
if (flags & CGROUP_REMOVE) {
r = cg_rmdir(cfrom, pfrom);
if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
return r;
}
return ret;
}
int cg_migrate_recursive_fallback(
const char *cfrom,
const char *pfrom,
const char *cto,
const char *pto,
CGroupFlags flags) {
int r;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
r = cg_migrate_recursive(cfrom, pfrom, cto, pto, flags);
if (r < 0) {
char prefix[strlen(pto) + 1];
/* This didn't work? Then let's try all prefixes of the destination */
PATH_FOREACH_PREFIX(prefix, pto) {
int q;
q = cg_migrate_recursive(cfrom, pfrom, cto, prefix, flags);
if (q >= 0)
return q;
}
}
return r;
}
static const char *controller_to_dirname(const char *controller) {
const char *e;
assert(controller);
/* Converts a controller name to the directory name below
* /sys/fs/cgroup/ we want to mount it to. Effectively, this
* just cuts off the name= prefixed used for named
* hierarchies, if it is specified. */
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
controller = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
e = startswith(controller, "name=");
if (e)
return e;
return controller;
}
static int join_path_legacy(const char *controller, const char *path, const char *suffix, char **fs) {
const char *dn;
char *t = NULL;
assert(fs);
assert(controller);
dn = controller_to_dirname(controller);
if (isempty(path) && isempty(suffix))
t = strappend("/sys/fs/cgroup/", dn);
else if (isempty(path))
t = strjoin("/sys/fs/cgroup/", dn, "/", suffix);
else if (isempty(suffix))
t = strjoin("/sys/fs/cgroup/", dn, "/", path);
else
t = strjoin("/sys/fs/cgroup/", dn, "/", path, "/", suffix);
if (!t)
return -ENOMEM;
*fs = t;
return 0;
}
static int join_path_unified(const char *path, const char *suffix, char **fs) {
char *t;
assert(fs);
if (isempty(path) && isempty(suffix))
t = strdup("/sys/fs/cgroup");
else if (isempty(path))
t = strappend("/sys/fs/cgroup/", suffix);
else if (isempty(suffix))
t = strappend("/sys/fs/cgroup/", path);
else
t = strjoin("/sys/fs/cgroup/", path, "/", suffix);
if (!t)
return -ENOMEM;
*fs = t;
return 0;
}
int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
int r;
assert(fs);
if (!controller) {
char *t;
/* If no controller is specified, we return the path
* *below* the controllers, without any prefix. */
if (!path && !suffix)
return -EINVAL;
if (!suffix)
t = strdup(path);
else if (!path)
t = strdup(suffix);
else
t = strjoin(path, "/", suffix);
if (!t)
return -ENOMEM;
*fs = path_kill_slashes(t);
return 0;
}
if (!cg_controller_is_valid(controller))
return -EINVAL;
if (cg_all_unified())
r = join_path_unified(path, suffix, fs);
else
r = join_path_legacy(controller, path, suffix, fs);
if (r < 0)
return r;
path_kill_slashes(*fs);
return 0;
}
static int controller_is_accessible(const char *controller) {
assert(controller);
/* Checks whether a specific controller is accessible,
* i.e. its hierarchy mounted. In the unified hierarchy all
* controllers are considered accessible, except for the named
* hierarchies */
if (!cg_controller_is_valid(controller))
return -EINVAL;
if (cg_all_unified()) {
/* We don't support named hierarchies if we are using
* the unified hierarchy. */
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
return 0;
if (startswith(controller, "name="))
return -EOPNOTSUPP;
} else {
const char *cc, *dn;
dn = controller_to_dirname(controller);
cc = strjoina("/sys/fs/cgroup/", dn);
if (laccess(cc, F_OK) < 0)
return -errno;
}
return 0;
}
int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) {
int r;
assert(controller);
assert(fs);
/* Check if the specified controller is actually accessible */
r = controller_is_accessible(controller);
if (r < 0)
return r;
return cg_get_path(controller, path, suffix, fs);
}
static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
assert(path);
assert(sb);
assert(ftwbuf);
if (typeflag != FTW_DP)
return 0;
if (ftwbuf->level < 1)
return 0;
(void) rmdir(path);
return 0;
}
int cg_trim(const char *controller, const char *path, bool delete_root) {
_cleanup_free_ char *fs = NULL;
int r = 0;
assert(path);
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
errno = 0;
if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0) {
if (errno == ENOENT)
r = 0;
else if (errno > 0)
r = -errno;
else
r = -EIO;
}
if (delete_root) {
if (rmdir(fs) < 0 && errno != ENOENT)
return -errno;
}
return r;
}
int cg_create(const char *controller, const char *path) {
_cleanup_free_ char *fs = NULL;
int r;
r = cg_get_path_and_check(controller, path, NULL, &fs);
if (r < 0)
return r;
r = mkdir_parents(fs, 0755);
if (r < 0)
return r;
if (mkdir(fs, 0755) < 0) {
if (errno == EEXIST)
return 0;
return -errno;
}
return 1;
}
int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
int r, q;
assert(pid >= 0);
r = cg_create(controller, path);
if (r < 0)
return r;
q = cg_attach(controller, path, pid);
if (q < 0)
return q;
/* This does not remove the cgroup on failure */
return r;
}
int cg_attach(const char *controller, const char *path, pid_t pid) {
_cleanup_free_ char *fs = NULL;
char c[DECIMAL_STR_MAX(pid_t) + 2];
int r;
assert(path);
assert(pid >= 0);
r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
if (pid == 0)
pid = getpid();
xsprintf(c, PID_FMT "\n", pid);
return write_string_file(fs, c, 0);
}
int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {
int r;
assert(controller);
assert(path);
assert(pid >= 0);
r = cg_attach(controller, path, pid);
if (r < 0) {
char prefix[strlen(path) + 1];
/* This didn't work? Then let's try all prefixes of
* the destination */
PATH_FOREACH_PREFIX(prefix, path) {
int q;
q = cg_attach(controller, prefix, pid);
if (q >= 0)
return q;
}
}
return r;
}
int cg_set_group_access(
const char *controller,
const char *path,
mode_t mode,
uid_t uid,
gid_t gid) {
_cleanup_free_ char *fs = NULL;
int r;
if (mode == MODE_INVALID && uid == UID_INVALID && gid == GID_INVALID)
return 0;
if (mode != MODE_INVALID)
mode &= 0777;
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
return chmod_and_chown(fs, mode, uid, gid);
}
int cg_set_task_access(
const char *controller,
const char *path,
mode_t mode,
uid_t uid,
gid_t gid) {
_cleanup_free_ char *fs = NULL, *procs = NULL;
int r;
assert(path);
if (mode == MODE_INVALID && uid == UID_INVALID && gid == GID_INVALID)
return 0;
if (mode != MODE_INVALID)
mode &= 0666;
r = cg_get_path(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
r = chmod_and_chown(fs, mode, uid, gid);
if (r < 0)
return r;
if (cg_unified(controller))
return 0;
/* Compatibility, Always keep values for "tasks" in sync with
* "cgroup.procs" */
if (cg_get_path(controller, path, "tasks", &procs) >= 0)
(void) chmod_and_chown(procs, mode, uid, gid);
return 0;
}
int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
assert(value || size <= 0);
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
if (setxattr(fs, name, value, size, flags) < 0)
return -errno;
return 0;
}
int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size) {
_cleanup_free_ char *fs = NULL;
ssize_t n;
int r;
assert(path);
assert(name);
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
n = getxattr(fs, name, value, size);
if (n < 0)
return -errno;
return (int) n;
}
int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
_cleanup_fclose_ FILE *f = NULL;
char line[LINE_MAX];
const char *fs, *controller_str;
size_t cs = 0;
bool unified;
assert(path);
assert(pid >= 0);
if (controller) {
if (!cg_controller_is_valid(controller))
return -EINVAL;
} else
controller = SYSTEMD_CGROUP_CONTROLLER;
unified = cg_unified(controller);
if (!unified) {
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
controller_str = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
else
controller_str = controller;
cs = strlen(controller_str);
}
fs = procfs_file_alloca(pid, "cgroup");
f = fopen(fs, "re");
if (!f)
return errno == ENOENT ? -ESRCH : -errno;
FOREACH_LINE(line, f, return -errno) {
char *e, *p;
truncate_nl(line);
if (unified) {
e = startswith(line, "0:");
if (!e)
continue;
e = strchr(e, ':');
if (!e)
continue;
} else {
char *l;
size_t k;
const char *word, *state;
bool found = false;
l = strchr(line, ':');
if (!l)
continue;
l++;
e = strchr(l, ':');
if (!e)
continue;
*e = 0;
FOREACH_WORD_SEPARATOR(word, k, l, ",", state) {
if (k == cs && memcmp(word, controller_str, cs) == 0) {
found = true;
break;
}
}
if (!found)
continue;
}
p = strdup(e + 1);
if (!p)
return -ENOMEM;
*path = p;
return 0;
}
return -ENODATA;
}
int cg_install_release_agent(const char *controller, const char *agent) {
_cleanup_free_ char *fs = NULL, *contents = NULL;
const char *sc;
int r;
assert(agent);
if (cg_unified(controller)) /* doesn't apply to unified hierarchy */
return -EOPNOTSUPP;
r = cg_get_path(controller, NULL, "release_agent", &fs);
if (r < 0)
return r;
r = read_one_line_file(fs, &contents);
if (r < 0)
return r;
sc = strstrip(contents);
if (isempty(sc)) {
r = write_string_file(fs, agent, 0);
if (r < 0)
return r;
} else if (!path_equal(sc, agent))
return -EEXIST;
fs = mfree(fs);
r = cg_get_path(controller, NULL, "notify_on_release", &fs);
if (r < 0)
return r;
contents = mfree(contents);
r = read_one_line_file(fs, &contents);
if (r < 0)
return r;
sc = strstrip(contents);
if (streq(sc, "0")) {
r = write_string_file(fs, "1", 0);
if (r < 0)
return r;
return 1;
}
if (!streq(sc, "1"))
return -EIO;
return 0;
}
int cg_uninstall_release_agent(const char *controller) {
_cleanup_free_ char *fs = NULL;
int r;
if (cg_unified(controller)) /* Doesn't apply to unified hierarchy */
return -EOPNOTSUPP;
r = cg_get_path(controller, NULL, "notify_on_release", &fs);
if (r < 0)
return r;
r = write_string_file(fs, "0", 0);
if (r < 0)
return r;
fs = mfree(fs);
r = cg_get_path(controller, NULL, "release_agent", &fs);
if (r < 0)
return r;
r = write_string_file(fs, "", 0);
if (r < 0)
return r;
return 0;
}
int cg_is_empty(const char *controller, const char *path) {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid;
int r;
assert(path);
r = cg_enumerate_processes(controller, path, &f);
if (r == -ENOENT)
return 1;
if (r < 0)
return r;
r = cg_read_pid(f, &pid);
if (r < 0)
return r;
return r == 0;
}
int cg_is_empty_recursive(const char *controller, const char *path) {
int r;
assert(path);
/* The root cgroup is always populated */
if (controller && (isempty(path) || path_equal(path, "/")))
return false;
if (cg_unified(controller)) {
_cleanup_free_ char *t = NULL;
/* On the unified hierarchy we can check empty state
* via the "populated" attribute of "cgroup.events". */
r = cg_read_event(controller, path, "populated", &t);
if (r < 0)
return r;
return streq(t, "0");
} else {
_cleanup_closedir_ DIR *d = NULL;
char *fn;
r = cg_is_empty(controller, path);
if (r <= 0)
return r;
r = cg_enumerate_subgroups(controller, path, &d);
if (r == -ENOENT)
return 1;
if (r < 0)
return r;
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(path, "/", fn);
free(fn);
if (!p)
return -ENOMEM;
r = cg_is_empty_recursive(controller, p);
if (r <= 0)
return r;
}
if (r < 0)
return r;
return true;
}
}
int cg_split_spec(const char *spec, char **controller, char **path) {
char *t = NULL, *u = NULL;
const char *e;
assert(spec);
if (*spec == '/') {
if (!path_is_safe(spec))
return -EINVAL;
if (path) {
t = strdup(spec);
if (!t)
return -ENOMEM;
*path = path_kill_slashes(t);
}
if (controller)
*controller = NULL;
return 0;
}
e = strchr(spec, ':');
if (!e) {
if (!cg_controller_is_valid(spec))
return -EINVAL;
if (controller) {
t = strdup(spec);
if (!t)
return -ENOMEM;
*controller = t;
}
if (path)
*path = NULL;
return 0;
}
t = strndup(spec, e-spec);
if (!t)
return -ENOMEM;
if (!cg_controller_is_valid(t)) {
free(t);
return -EINVAL;
}
if (isempty(e+1))
u = NULL;
else {
u = strdup(e+1);
if (!u) {
free(t);
return -ENOMEM;
}
if (!path_is_safe(u) ||
!path_is_absolute(u)) {
free(t);
free(u);
return -EINVAL;
}
path_kill_slashes(u);
}
if (controller)
*controller = t;
else
free(t);
if (path)
*path = u;
else
free(u);
return 0;
}
int cg_mangle_path(const char *path, char **result) {
_cleanup_free_ char *c = NULL, *p = NULL;
char *t;
int r;
assert(path);
assert(result);
/* First, check if it already is a filesystem path */
if (path_startswith(path, "/sys/fs/cgroup")) {
t = strdup(path);
if (!t)
return -ENOMEM;
*result = path_kill_slashes(t);
return 0;
}
/* Otherwise, treat it as cg spec */
r = cg_split_spec(path, &c, &p);
if (r < 0)
return r;
return cg_get_path(c ?: SYSTEMD_CGROUP_CONTROLLER, p ?: "/", NULL, result);
}
int cg_get_root_path(char **path) {
char *p, *e;
int r;
assert(path);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
if (r < 0)
return r;
e = endswith(p, "/" SPECIAL_INIT_SCOPE);
if (!e)
e = endswith(p, "/" SPECIAL_SYSTEM_SLICE); /* legacy */
if (!e)
e = endswith(p, "/system"); /* even more legacy */
if (e)
*e = 0;
*path = p;
return 0;
}
int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
_cleanup_free_ char *rt = NULL;
char *p;
int r;
assert(cgroup);
assert(shifted);
if (!root) {
/* If the root was specified let's use that, otherwise
* let's determine it from PID 1 */
r = cg_get_root_path(&rt);
if (r < 0)
return r;
root = rt;
}
p = path_startswith(cgroup, root);
if (p && p > cgroup)
*shifted = p - 1;
else
*shifted = cgroup;
return 0;
}
int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
_cleanup_free_ char *raw = NULL;
const char *c;
int r;
assert(pid >= 0);
assert(cgroup);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
if (r < 0)
return r;
r = cg_shift_path(raw, root, &c);
if (r < 0)
return r;
if (c == raw) {
*cgroup = raw;
raw = NULL;
} else {
char *n;
n = strdup(c);
if (!n)
return -ENOMEM;
*cgroup = n;
}
return 0;
}
int cg_path_decode_unit(const char *cgroup, char **unit) {
char *c, *s;
size_t n;
assert(cgroup);
assert(unit);
n = strcspn(cgroup, "/");
if (n < 3)
return -ENXIO;
c = strndupa(cgroup, n);
c = cg_unescape(c);
if (!unit_name_is_valid(c, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
return -ENXIO;
s = strdup(c);
if (!s)
return -ENOMEM;
*unit = s;
return 0;
}
static bool valid_slice_name(const char *p, size_t n) {
if (!p)
return false;
if (n < strlen("x.slice"))
return false;
if (memcmp(p + n - 6, ".slice", 6) == 0) {
char buf[n+1], *c;
memcpy(buf, p, n);
buf[n] = 0;
c = cg_unescape(buf);
return unit_name_is_valid(c, UNIT_NAME_PLAIN);
}
return false;
}
static const char *skip_slices(const char *p) {
assert(p);
/* Skips over all slice assignments */
for (;;) {
size_t n;
p += strspn(p, "/");
n = strcspn(p, "/");
if (!valid_slice_name(p, n))
return p;
p += n;
}
}
int cg_path_get_unit(const char *path, char **ret) {
const char *e;
char *unit;
int r;
assert(path);
assert(ret);
e = skip_slices(path);
r = cg_path_decode_unit(e, &unit);
if (r < 0)
return r;
/* We skipped over the slices, don't accept any now */
if (endswith(unit, ".slice")) {
free(unit);
return -ENXIO;
}
*ret = unit;
return 0;
}
int cg_pid_get_unit(pid_t pid, char **unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(unit);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_unit(cgroup, unit);
}
/**
* Skip session-*.scope, but require it to be there.
*/
static const char *skip_session(const char *p) {
size_t n;
if (isempty(p))
return NULL;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < strlen("session-x.scope"))
return NULL;
if (memcmp(p, "session-", 8) == 0 && memcmp(p + n - 6, ".scope", 6) == 0) {
char buf[n - 8 - 6 + 1];
memcpy(buf, p + 8, n - 8 - 6);
buf[n - 8 - 6] = 0;
/* Note that session scopes never need unescaping,
* since they cannot conflict with the kernel's own
* names, hence we don't need to call cg_unescape()
* here. */
if (!session_id_valid(buf))
return false;
p += n;
p += strspn(p, "/");
return p;
}
return NULL;
}
/**
* Skip user@*.service, but require it to be there.
*/
static const char *skip_user_manager(const char *p) {
size_t n;
if (isempty(p))
return NULL;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < strlen("user@x.service"))
return NULL;
if (memcmp(p, "user@", 5) == 0 && memcmp(p + n - 8, ".service", 8) == 0) {
char buf[n - 5 - 8 + 1];
memcpy(buf, p + 5, n - 5 - 8);
buf[n - 5 - 8] = 0;
/* Note that user manager services never need unescaping,
* since they cannot conflict with the kernel's own
* names, hence we don't need to call cg_unescape()
* here. */
if (parse_uid(buf, NULL) < 0)
return NULL;
p += n;
p += strspn(p, "/");
return p;
}
return NULL;
}
static const char *skip_user_prefix(const char *path) {
const char *e, *t;
assert(path);
/* Skip slices, if there are any */
e = skip_slices(path);
/* Skip the user manager, if it's in the path now... */
t = skip_user_manager(e);
if (t)
return t;
/* Alternatively skip the user session if it is in the path... */
return skip_session(e);
}
int cg_path_get_user_unit(const char *path, char **ret) {
const char *t;
assert(path);
assert(ret);
t = skip_user_prefix(path);
if (!t)
return -ENXIO;
/* And from here on it looks pretty much the same as for a
* system unit, hence let's use the same parser from here
* on. */
return cg_path_get_unit(t, ret);
}
int cg_pid_get_user_unit(pid_t pid, char **unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(unit);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_user_unit(cgroup, unit);
}
int cg_path_get_machine_name(const char *path, char **machine) {
_cleanup_free_ char *u = NULL;
const char *sl;
int r;
r = cg_path_get_unit(path, &u);
if (r < 0)
return r;
sl = strjoina("/run/systemd/machines/unit:", u);
return readlink_malloc(sl, machine);
}
int cg_pid_get_machine_name(pid_t pid, char **machine) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(machine);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_machine_name(cgroup, machine);
}
int cg_path_get_session(const char *path, char **session) {
_cleanup_free_ char *unit = NULL;
char *start, *end;
int r;
assert(path);
r = cg_path_get_unit(path, &unit);
if (r < 0)
return r;
start = startswith(unit, "session-");
if (!start)
return -ENXIO;
end = endswith(start, ".scope");
if (!end)
return -ENXIO;
*end = 0;
if (!session_id_valid(start))
return -ENXIO;
if (session) {
char *rr;
rr = strdup(start);
if (!rr)
return -ENOMEM;
*session = rr;
}
return 0;
}
int cg_pid_get_session(pid_t pid, char **session) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_session(cgroup, session);
}
int cg_path_get_owner_uid(const char *path, uid_t *uid) {
_cleanup_free_ char *slice = NULL;
char *start, *end;
int r;
assert(path);
r = cg_path_get_slice(path, &slice);
if (r < 0)
return r;
start = startswith(slice, "user-");
if (!start)
return -ENXIO;
end = endswith(start, ".slice");
if (!end)
return -ENXIO;
*end = 0;
if (parse_uid(start, uid) < 0)
return -ENXIO;
return 0;
}
int cg_pid_get_owner_uid(pid_t pid, uid_t *uid) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_owner_uid(cgroup, uid);
}
int cg_path_get_slice(const char *p, char **slice) {
const char *e = NULL;
assert(p);
assert(slice);
/* Finds the right-most slice unit from the beginning, but
* stops before we come to the first non-slice unit. */
for (;;) {
size_t n;
p += strspn(p, "/");
n = strcspn(p, "/");
if (!valid_slice_name(p, n)) {
if (!e) {
char *s;
s = strdup(SPECIAL_ROOT_SLICE);
if (!s)
return -ENOMEM;
*slice = s;
return 0;
}
return cg_path_decode_unit(e, slice);
}
e = p;
p += n;
}
}
int cg_pid_get_slice(pid_t pid, char **slice) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(slice);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_slice(cgroup, slice);
}
int cg_path_get_user_slice(const char *p, char **slice) {
const char *t;
assert(p);
assert(slice);
t = skip_user_prefix(p);
if (!t)
return -ENXIO;
/* And now it looks pretty much the same as for a system
* slice, so let's just use the same parser from here on. */
return cg_path_get_slice(t, slice);
}
int cg_pid_get_user_slice(pid_t pid, char **slice) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(slice);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_user_slice(cgroup, slice);
}
char *cg_escape(const char *p) {
bool need_prefix = false;
/* This implements very minimal escaping for names to be used
* as file names in the cgroup tree: any name which might
* conflict with a kernel name or is prefixed with '_' is
* prefixed with a '_'. That way, when reading cgroup names it
* is sufficient to remove a single prefixing underscore if
* there is one. */
/* The return value of this function (unlike cg_unescape())
* needs free()! */
if (p[0] == 0 ||
p[0] == '_' ||
p[0] == '.' ||
streq(p, "notify_on_release") ||
streq(p, "release_agent") ||
streq(p, "tasks") ||
startswith(p, "cgroup."))
need_prefix = true;
else {
const char *dot;
dot = strrchr(p, '.');
if (dot) {
CGroupController c;
size_t l = dot - p;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
const char *n;
n = cgroup_controller_to_string(c);
if (l != strlen(n))
continue;
if (memcmp(p, n, l) != 0)
continue;
need_prefix = true;
break;
}
}
}
if (need_prefix)
return strappend("_", p);
return strdup(p);
}
char *cg_unescape(const char *p) {
assert(p);
/* The return value of this function (unlike cg_escape())
* doesn't need free()! */
if (p[0] == '_')
return (char*) p+1;
return (char*) p;
}
#define CONTROLLER_VALID \
DIGITS LETTERS \
"_"
bool cg_controller_is_valid(const char *p) {
const char *t, *s;
if (!p)
return false;
if (streq(p, SYSTEMD_CGROUP_CONTROLLER))
return true;
s = startswith(p, "name=");
if (s)
p = s;
if (*p == 0 || *p == '_')
return false;
for (t = p; *t; t++)
if (!strchr(CONTROLLER_VALID, *t))
return false;
if (t - p > FILENAME_MAX)
return false;
return true;
}
int cg_slice_to_path(const char *unit, char **ret) {
_cleanup_free_ char *p = NULL, *s = NULL, *e = NULL;
const char *dash;
int r;
assert(unit);
assert(ret);
if (streq(unit, SPECIAL_ROOT_SLICE)) {
char *x;
x = strdup("");
if (!x)
return -ENOMEM;
*ret = x;
return 0;
}
if (!unit_name_is_valid(unit, UNIT_NAME_PLAIN))
return -EINVAL;
if (!endswith(unit, ".slice"))
return -EINVAL;
r = unit_name_to_prefix(unit, &p);
if (r < 0)
return r;
dash = strchr(p, '-');
/* Don't allow initial dashes */
if (dash == p)
return -EINVAL;
while (dash) {
_cleanup_free_ char *escaped = NULL;
char n[dash - p + sizeof(".slice")];
/* Don't allow trailing or double dashes */
if (dash[1] == 0 || dash[1] == '-')
return -EINVAL;
strcpy(stpncpy(n, p, dash - p), ".slice");
if (!unit_name_is_valid(n, UNIT_NAME_PLAIN))
return -EINVAL;
escaped = cg_escape(n);
if (!escaped)
return -ENOMEM;
if (!strextend(&s, escaped, "/", NULL))
return -ENOMEM;
dash = strchr(dash+1, '-');
}
e = cg_escape(unit);
if (!e)
return -ENOMEM;
if (!strextend(&s, e, NULL))
return -ENOMEM;
*ret = s;
s = NULL;
return 0;
}
int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) {
_cleanup_free_ char *p = NULL;
int r;
r = cg_get_path(controller, path, attribute, &p);
if (r < 0)
return r;
return write_string_file(p, value, 0);
}
int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) {
_cleanup_free_ char *p = NULL;
int r;
r = cg_get_path(controller, path, attribute, &p);
if (r < 0)
return r;
return read_one_line_file(p, ret);
}
int cg_get_keyed_attribute(const char *controller, const char *path, const char *attribute, const char **keys, char **values) {
_cleanup_free_ char *filename = NULL, *content = NULL;
char *line, *p;
int i, r;
for (i = 0; keys[i]; i++)
values[i] = NULL;
r = cg_get_path(controller, path, attribute, &filename);
if (r < 0)
return r;
r = read_full_file(filename, &content, NULL);
if (r < 0)
return r;
p = content;
while ((line = strsep(&p, "\n"))) {
char *key;
key = strsep(&line, " ");
for (i = 0; keys[i]; i++) {
if (streq(key, keys[i])) {
values[i] = strdup(line);
break;
}
}
}
for (i = 0; keys[i]; i++) {
if (!values[i]) {
for (i = 0; keys[i]; i++) {
free(values[i]);
values[i] = NULL;
}
return -ENOENT;
}
}
return 0;
}
int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) {
CGroupController c;
int r;
/* This one will create a cgroup in our private tree, but also
* duplicate it in the trees specified in mask, and remove it
* in all others */
/* First create the cgroup in our own hierarchy. */
r = cg_create(SYSTEMD_CGROUP_CONTROLLER, path);
if (r < 0)
return r;
/* If we are in the unified hierarchy, we are done now */
if (cg_all_unified())
return 0;
/* Otherwise, do the same in the other hierarchies */
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *n;
n = cgroup_controller_to_string(c);
if (mask & bit)
(void) cg_create(n, path);
else if (supported & bit)
(void) cg_trim(n, path, true);
}
return 0;
}
int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) {
CGroupController c;
int r;
r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
if (r < 0)
return r;
if (cg_all_unified())
return 0;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *p = NULL;
if (!(supported & bit))
continue;
if (path_callback)
p = path_callback(bit, userdata);
if (!p)
p = path;
(void) cg_attach_fallback(cgroup_controller_to_string(c), p, pid);
}
return 0;
}
int cg_attach_many_everywhere(CGroupMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) {
Iterator i;
void *pidp;
int r = 0;
SET_FOREACH(pidp, pids, i) {
pid_t pid = PTR_TO_PID(pidp);
int q;
q = cg_attach_everywhere(supported, path, pid, path_callback, userdata);
if (q < 0 && r >= 0)
r = q;
}
return r;
}
int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
CGroupController c;
int r = 0;
if (!path_equal(from, to)) {
r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, CGROUP_REMOVE);
if (r < 0)
return r;
}
if (cg_all_unified())
return r;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *p = NULL;
if (!(supported & bit))
continue;
if (to_callback)
p = to_callback(bit, userdata);
if (!p)
p = to;
(void) cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, cgroup_controller_to_string(c), p, 0);
}
return 0;
}
int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) {
CGroupController c;
int r;
r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
if (r < 0)
return r;
if (cg_all_unified())
return r;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
if (!(supported & bit))
continue;
(void) cg_trim(cgroup_controller_to_string(c), path, delete_root);
}
return 0;
}
int cg_mask_supported(CGroupMask *ret) {
CGroupMask mask = 0;
int r;
/* Determines the mask of supported cgroup controllers. Only
* includes controllers we can make sense of and that are
* actually accessible. */
if (cg_all_unified()) {
_cleanup_free_ char *root = NULL, *controllers = NULL, *path = NULL;
const char *c;
/* In the unified hierarchy we can read the supported
* and accessible controllers from a the top-level
* cgroup attribute */
r = cg_get_root_path(&root);
if (r < 0)
return r;
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, "cgroup.controllers", &path);
if (r < 0)
return r;
r = read_one_line_file(path, &controllers);
if (r < 0)
return r;
c = controllers;
for (;;) {
_cleanup_free_ char *n = NULL;
CGroupController v;
r = extract_first_word(&c, &n, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
v = cgroup_controller_from_string(n);
if (v < 0)
continue;
mask |= CGROUP_CONTROLLER_TO_MASK(v);
}
/* Currently, we support the cpu, memory, io and pids
* controller in the unified hierarchy, mask
* everything else off. */
mask &= CGROUP_MASK_CPU | CGROUP_MASK_MEMORY | CGROUP_MASK_IO | CGROUP_MASK_PIDS;
} else {
CGroupController c;
/* In the legacy hierarchy, we check whether which
* hierarchies are mounted. */
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
const char *n;
n = cgroup_controller_to_string(c);
if (controller_is_accessible(n) >= 0)
mask |= CGROUP_CONTROLLER_TO_MASK(c);
}
}
*ret = mask;
return 0;
}
int cg_kernel_controllers(Set *controllers) {
_cleanup_fclose_ FILE *f = NULL;
char buf[LINE_MAX];
int r;
assert(controllers);
/* Determines the full list of kernel-known controllers. Might
* include controllers we don't actually support, arbitrary
* named hierarchies and controllers that aren't currently
* accessible (because not mounted). */
f = fopen("/proc/cgroups", "re");
if (!f) {
if (errno == ENOENT)
return 0;
return -errno;
}
/* Ignore the header line */
(void) fgets(buf, sizeof(buf), f);
for (;;) {
char *controller;
int enabled = 0;
errno = 0;
if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
if (feof(f))
break;
if (ferror(f) && errno > 0)
return -errno;
return -EBADMSG;
}
if (!enabled) {
free(controller);
continue;
}
if (!cg_controller_is_valid(controller)) {
free(controller);
return -EBADMSG;
}
r = set_consume(controllers, controller);
if (r < 0)
return r;
}
return 0;
}
static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN;
static int cg_update_unified(void) {
struct statfs fs;
/* Checks if we support the unified hierarchy. Returns an
* error when the cgroup hierarchies aren't mounted yet or we
* have any other trouble determining if the unified hierarchy
* is supported. */
if (unified_cache >= CGROUP_UNIFIED_NONE)
return 0;
if (statfs("/sys/fs/cgroup/", &fs) < 0)
return -errno;
if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC))
unified_cache = CGROUP_UNIFIED_ALL;
else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC)) {
if (statfs("/sys/fs/cgroup/systemd/", &fs) < 0)
return -errno;
unified_cache = F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC) ?
CGROUP_UNIFIED_SYSTEMD : CGROUP_UNIFIED_NONE;
} else
return -ENOMEDIUM;
return 0;
}
bool cg_unified(const char *controller) {
assert(cg_update_unified() >= 0);
if (streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER))
return unified_cache >= CGROUP_UNIFIED_SYSTEMD;
else
return unified_cache >= CGROUP_UNIFIED_ALL;
}
bool cg_all_unified(void) {
return cg_unified(NULL);
}
int cg_unified_flush(void) {
unified_cache = CGROUP_UNIFIED_UNKNOWN;
return cg_update_unified();
}
int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
_cleanup_free_ char *fs = NULL;
CGroupController c;
int r;
assert(p);
if (supported == 0)
return 0;
if (!cg_all_unified()) /* on the legacy hiearchy there's no joining of controllers defined */
return 0;
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, p, "cgroup.subtree_control", &fs);
if (r < 0)
return r;
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *n;
if (!(supported & bit))
continue;
n = cgroup_controller_to_string(c);
{
char s[1 + strlen(n) + 1];
s[0] = mask & bit ? '+' : '-';
strcpy(s + 1, n);
r = write_string_file(fs, s, 0);
if (r < 0)
log_debug_errno(r, "Failed to enable controller %s for %s (%s): %m", n, p, fs);
}
}
return 0;
}
bool cg_is_unified_wanted(void) {
static thread_local int wanted = -1;
int r;
bool b;
/* If the hierarchy is already mounted, then follow whatever
* was chosen for it. */
if (cg_unified_flush() >= 0)
return cg_all_unified();
/* Otherwise, let's see what the kernel command line has to
* say. Since checking that is expensive, let's cache the
* result. */
if (wanted >= 0)
return wanted;
r = proc_cmdline_get_bool("systemd.unified_cgroup_hierarchy", &b);
if (r < 0)
return false;
return (wanted = r > 0 ? b : false);
}
bool cg_is_legacy_wanted(void) {
return !cg_is_unified_wanted();
}
bool cg_is_unified_systemd_controller_wanted(void) {
static thread_local int wanted = -1;
int r;
bool b;
/* If the unified hierarchy is requested in full, no need to
* bother with this. */
if (cg_is_unified_wanted())
return 0;
/* If the hierarchy is already mounted, then follow whatever
* was chosen for it. */
if (cg_unified_flush() >= 0)
return cg_unified(SYSTEMD_CGROUP_CONTROLLER);
/* Otherwise, let's see what the kernel command line has to
* say. Since checking that is expensive, let's cache the
* result. */
if (wanted >= 0)
return wanted;
r = proc_cmdline_get_bool("systemd.legacy_systemd_cgroup_controller", &b);
if (r < 0)
return false;
return (wanted = r > 0 ? b : false);
}
bool cg_is_legacy_systemd_controller_wanted(void) {
return cg_is_legacy_wanted() && !cg_is_unified_systemd_controller_wanted();
}
int cg_weight_parse(const char *s, uint64_t *ret) {
uint64_t u;
int r;
if (isempty(s)) {
*ret = CGROUP_WEIGHT_INVALID;
return 0;
}
r = safe_atou64(s, &u);
if (r < 0)
return r;
if (u < CGROUP_WEIGHT_MIN || u > CGROUP_WEIGHT_MAX)
return -ERANGE;
*ret = u;
return 0;
}
const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX] = {
[CGROUP_IO_RBPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_WBPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_RIOPS_MAX] = CGROUP_LIMIT_MAX,
[CGROUP_IO_WIOPS_MAX] = CGROUP_LIMIT_MAX,
};
static const char* const cgroup_io_limit_type_table[_CGROUP_IO_LIMIT_TYPE_MAX] = {
[CGROUP_IO_RBPS_MAX] = "IOReadBandwidthMax",
[CGROUP_IO_WBPS_MAX] = "IOWriteBandwidthMax",
[CGROUP_IO_RIOPS_MAX] = "IOReadIOPSMax",
[CGROUP_IO_WIOPS_MAX] = "IOWriteIOPSMax",
};
DEFINE_STRING_TABLE_LOOKUP(cgroup_io_limit_type, CGroupIOLimitType);
int cg_cpu_shares_parse(const char *s, uint64_t *ret) {
uint64_t u;
int r;
if (isempty(s)) {
*ret = CGROUP_CPU_SHARES_INVALID;
return 0;
}
r = safe_atou64(s, &u);
if (r < 0)
return r;
if (u < CGROUP_CPU_SHARES_MIN || u > CGROUP_CPU_SHARES_MAX)
return -ERANGE;
*ret = u;
return 0;
}
int cg_blkio_weight_parse(const char *s, uint64_t *ret) {
uint64_t u;
int r;
if (isempty(s)) {
*ret = CGROUP_BLKIO_WEIGHT_INVALID;
return 0;
}
r = safe_atou64(s, &u);
if (r < 0)
return r;
if (u < CGROUP_BLKIO_WEIGHT_MIN || u > CGROUP_BLKIO_WEIGHT_MAX)
return -ERANGE;
*ret = u;
return 0;
}
bool is_cgroup_fs(const struct statfs *s) {
return is_fs_type(s, CGROUP_SUPER_MAGIC) ||
is_fs_type(s, CGROUP2_SUPER_MAGIC);
}
bool fd_is_cgroup_fs(int fd) {
struct statfs s;
if (fstatfs(fd, &s) < 0)
return -errno;
return is_cgroup_fs(&s);
}
static const char *cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = {
[CGROUP_CONTROLLER_CPU] = "cpu",
[CGROUP_CONTROLLER_CPUACCT] = "cpuacct",
[CGROUP_CONTROLLER_IO] = "io",
[CGROUP_CONTROLLER_BLKIO] = "blkio",
[CGROUP_CONTROLLER_MEMORY] = "memory",
[CGROUP_CONTROLLER_DEVICES] = "devices",
[CGROUP_CONTROLLER_PIDS] = "pids",
};
DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController);
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