cgroup-util.c revision 8c6db8336536916d0476ff8233e0abf40a2f6aab
/*-*- Mode: C; c-basic-offset: 8 -*-*/
/***
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 General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#include <libcgroup.h>
#include "cgroup-util.h"
#include "log.h"
#include "set.h"
#include "macro.h"
#include "util.h"
int cg_translate_error(int error, int _errno) {
switch (error) {
case ECGROUPNOTCOMPILED:
case ECGROUPNOTMOUNTED:
case ECGROUPNOTEXIST:
case ECGROUPNOTCREATED:
return -ENOENT;
case ECGINVAL:
return -EINVAL;
case ECGROUPNOTALLOWED:
return -EPERM;
case ECGOTHER:
return -_errno;
}
return -EIO;
}
static struct cgroup* cg_new(const char *controller, const char *path) {
struct cgroup *cgroup;
assert(path);
assert(controller);
if (!(cgroup = cgroup_new_cgroup(path)))
return NULL;
if (!cgroup_add_controller(cgroup, controller)) {
cgroup_free(&cgroup);
return NULL;
}
return cgroup;
}
int cg_kill(const char *controller, const char *path, int sig, bool ignore_self) {
bool killed = false, done = false;
Set *s;
pid_t my_pid;
int r, ret = 0;
assert(controller);
assert(path);
assert(sig >= 0);
/* 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 = set_new(trivial_hash_func, trivial_compare_func)))
return -ENOMEM;
my_pid = getpid();
do {
void *iterator = NULL;
pid_t pid = 0;
done = true;
r = cgroup_get_task_begin(path, controller, &iterator, &pid);
while (r == 0) {
if (pid == my_pid && ignore_self)
goto next;
if (set_get(s, INT_TO_PTR(pid)) == INT_TO_PTR(pid))
goto next;
/* If we haven't killed this process yet, kill
* it */
if (kill(pid, sig) < 0 && errno != ESRCH) {
if (ret == 0)
ret = -errno;
}
killed = true;
done = false;
if ((r = set_put(s, INT_TO_PTR(pid))) < 0)
goto loop_exit;
next:
r = cgroup_get_task_next(&iterator, &pid);
}
if (r == 0 || r == ECGEOF)
r = 0;
else if (r == ECGOTHER && errno == ENOENT)
r = -ESRCH;
else
r = cg_translate_error(r, errno);
loop_exit:
assert_se(cgroup_get_task_end(&iterator) == 0);
/* 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 && r >= 0);
set_free(s);
if (ret < 0)
return ret;
if (r < 0)
return r;
return !!killed;
}
int cg_kill_recursive(const char *controller, const char *path, int sig, bool ignore_self) {
struct cgroup_file_info info;
int level = 0, r, ret = 0;
void *iterator = NULL;
bool killed = false;
assert(path);
assert(controller);
assert(sig >= 0);
zero(info);
r = cgroup_walk_tree_begin(controller, path, 0, &iterator, &info, &level);
while (r == 0) {
int k;
char *p;
if (info.type != CGROUP_FILE_TYPE_DIR)
goto next;
if (asprintf(&p, "%s/%s", path, info.path) < 0) {
ret = -ENOMEM;
break;
}
k = cg_kill(controller, p, sig, ignore_self);
free(p);
if (k < 0) {
if (ret == 0)
ret = k;
} else if (k > 0)
killed = true;
next:
r = cgroup_walk_tree_next(0, &iterator, &info, level);
}
if (ret == 0) {
if (r == 0 || r == ECGEOF)
ret = !!killed;
else if (r == ECGOTHER && errno == ENOENT)
ret = -ESRCH;
else
ret = cg_translate_error(r, errno);
}
assert_se(cgroup_walk_tree_end(&iterator) == 0);
return ret;
}
int cg_kill_recursive_and_wait(const char *controller, const char *path) {
unsigned i;
assert(path);
assert(controller);
/* This safely kills all processes; first it sends a SIGTERM,
* then checks 8 times after 50ms whether the group is
* now empty, and finally kills everything that is left with
* SIGKILL */
for (i = 0; i < 10; i++) {
int sig, r;
if (i <= 0)
sig = SIGTERM;
else if (i >= 9)
sig = SIGKILL;
else
sig = 0;
if ((r = cg_kill_recursive(controller, path, sig, true)) <= 0)
return r;
usleep(50 * USEC_PER_MSEC);
}
return 0;
}
int cg_migrate(const char *controller, const char *from, const char *to, bool ignore_self) {
bool migrated = false, done = false;
struct cgroup *dest;
int r, ret = 0;
pid_t my_pid;
assert(controller);
assert(from);
assert(to);
if (!(dest = cg_new(controller, to)))
return -ENOMEM;
my_pid = getpid();
do {
void *iterator = NULL;
pid_t pid = 0;
done = true;
r = cgroup_get_task_begin(from, controller, &iterator, &pid);
while (r == 0) {
if (pid == my_pid && ignore_self)
goto next;
if ((r = cgroup_attach_task_pid(dest, pid)) != 0) {
if (ret == 0)
r = cg_translate_error(r, errno);
}
migrated = true;
done = false;
next:
r = cgroup_get_task_next(&iterator, &pid);
}
if (r == 0 || r == ECGEOF)
r = 0;
else if (r == ECGOTHER && errno == ENOENT)
r = -ESRCH;
else
r = cg_translate_error(r, errno);
assert_se(cgroup_get_task_end(&iterator) == 0);
} while (!done && r >= 0);
cgroup_free(&dest);
if (ret < 0)
return ret;
if (r < 0)
return r;
return !!migrated;
}
int cg_migrate_recursive(const char *controller, const char *from, const char *to, bool ignore_self) {
struct cgroup_file_info info;
int level = 0, r, ret = 0;
void *iterator = NULL;
bool migrated = false;
assert(controller);
assert(from);
assert(to);
zero(info);
r = cgroup_walk_tree_begin(controller, from, 0, &iterator, &info, &level);
while (r == 0) {
int k;
char *p;
if (info.type != CGROUP_FILE_TYPE_DIR)
goto next;
if (asprintf(&p, "%s/%s", from, info.path) < 0) {
ret = -ENOMEM;
break;
}
k = cg_migrate(controller, p, to, ignore_self);
free(p);
if (k < 0) {
if (ret == 0)
ret = k;
} else if (k > 0)
migrated = true;
next:
r = cgroup_walk_tree_next(0, &iterator, &info, level);
}
if (ret == 0) {
if (r == 0 || r == ECGEOF)
r = !!migrated;
else if (r == ECGOTHER && errno == ENOENT)
r = -ESRCH;
else
r = cg_translate_error(r, errno);
}
assert_se(cgroup_walk_tree_end(&iterator) == 0);
return ret;
}
int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
char *mp;
int r;
assert(controller);
assert(path);
if ((r = cgroup_get_subsys_mount_point(controller, &mp)) != 0)
return cg_translate_error(r, errno);
if (suffix)
r = asprintf(fs, "%s/%s/%s", mp, path, suffix);
else
r = asprintf(fs, "%s/%s", mp, path);
free(mp);
return r < 0 ? -ENOMEM : 0;
}
int cg_trim(const char *controller, const char *path, bool delete_root) {
char *fs;
int r;
assert(controller);
assert(path);
if ((r = cg_get_path(controller, path, NULL, &fs)) < 0)
return r;
r = rm_rf(fs, true, delete_root);
free(fs);
return r;
}
int cg_delete(const char *controller, const char *path) {
struct cgroup *cg;
int r;
assert(controller);
assert(path);
if (!(cg = cg_new(controller, path)))
return -ENOMEM;
if ((r = cgroup_delete_cgroup_ext(cg, CGFLAG_DELETE_RECURSIVE|CGFLAG_DELETE_IGNORE_MIGRATION)) != 0) {
r = cg_translate_error(r, errno);
goto finish;
}
r = 0;
finish:
cgroup_free(&cg);
return r;
}
int cg_create(const char *controller, const char *path) {
struct cgroup *cg;
int r;
assert(controller);
assert(path);
if (!(cg = cg_new(controller, path)))
return -ENOMEM;
if ((r = cgroup_create_cgroup(cg, 1)) != 0) {
r = cg_translate_error(r, errno);
goto finish;
}
r = 0;
finish:
cgroup_free(&cg);
return r;
}
int cg_attach(const char *controller, const char *path, pid_t pid) {
struct cgroup *cg;
int r;
assert(controller);
assert(path);
assert(pid >= 0);
if (!(cg = cg_new(controller, path)))
return -ENOMEM;
if (pid == 0)
pid = getpid();
if ((r = cgroup_attach_task_pid(cg, pid))) {
r = cg_translate_error(r, errno);
goto finish;
}
r = 0;
finish:
cgroup_free(&cg);
return r;
}
int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
struct cgroup *cg;
int r;
assert(controller);
assert(path);
assert(pid >= 0);
if (!(cg = cg_new(controller, path)))
return -ENOMEM;
if ((r = cgroup_create_cgroup(cg, 1)) != 0) {
r = cg_translate_error(r, errno);
goto finish;
}
if (pid == 0)
pid = getpid();
if ((r = cgroup_attach_task_pid(cg, pid))) {
r = cg_translate_error(r, errno);
goto finish;
}
r = 0;
finish:
cgroup_free(&cg);
return r;
}
int cg_set_group_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid) {
char *fs;
int r;
assert(controller);
assert(path);
if ((r = cg_get_path(controller, path, NULL, &fs)) < 0)
return r;
r = chmod_and_chown(fs, mode, uid, gid);
free(fs);
return r;
}
int cg_set_task_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid) {
char *fs;
int r;
assert(controller);
assert(path);
if ((r = cg_get_path(controller, path, "tasks", &fs)) < 0)
return r;
r = chmod_and_chown(fs, mode, uid, gid);
free(fs);
return r;
}
int cg_get_by_pid(const char *controller, pid_t pid, char **path) {
int r;
char *p = NULL;
assert(controller);
assert(pid > 0);
assert(path);
if ((r = cgroup_get_current_controller_path(pid, controller, &p)) != 0)
return cg_translate_error(r, errno);
assert(p);
*path = p;
return 0;
}
int cg_install_release_agent(const char *controller, const char *agent) {
char *mp = NULL, *path = NULL, *contents = NULL, *line = NULL, *sc;
int r;
assert(controller);
assert(agent);
if ((r = cgroup_get_subsys_mount_point(controller, &mp)) != 0)
return cg_translate_error(r, errno);
if (asprintf(&path, "%s/release_agent", mp) < 0) {
r = -ENOMEM;
goto finish;
}
if ((r = read_one_line_file(path, &contents)) < 0)
goto finish;
sc = strstrip(contents);
if (sc[0] == 0) {
if (asprintf(&line, "%s\n", agent) < 0) {
r = -ENOMEM;
goto finish;
}
if ((r = write_one_line_file(path, line)) < 0)
goto finish;
} else if (!streq(sc, agent)) {
r = -EEXIST;
goto finish;
}
free(path);
path = NULL;
if (asprintf(&path, "%s/notify_on_release", mp) < 0) {
r = -ENOMEM;
goto finish;
}
free(contents);
contents = NULL;
if ((r = read_one_line_file(path, &contents)) < 0)
goto finish;
sc = strstrip(contents);
if (streq(sc, "0")) {
if ((r = write_one_line_file(path, "1\n")) < 0)
goto finish;
} else if (!streq(sc, "1")) {
r = -EIO;
goto finish;
}
r = 0;
finish:
free(mp);
free(path);
free(contents);
free(line);
return r;
}
int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
void *iterator = NULL;
pid_t pid = 0;
int r;
assert(controller);
assert(path);
r = cgroup_get_task_begin(path, controller, &iterator, &pid);
while (r == 0) {
if (ignore_self&& pid == getpid())
goto next;
break;
next:
r = cgroup_get_task_next(&iterator, &pid);
}
if (r == ECGEOF)
r = 1;
else if (r != 0)
r = cg_translate_error(r, errno);
else
r = 0;
assert_se(cgroup_get_task_end(&iterator) == 0);
return r;
}
int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
struct cgroup_file_info info;
int level = 0, r, ret = 0;
void *iterator = NULL;
bool empty = true;
assert(controller);
assert(path);
zero(info);
r = cgroup_walk_tree_begin(controller, path, 0, &iterator, &info, &level);
while (r == 0) {
int k;
char *p;
if (info.type != CGROUP_FILE_TYPE_DIR)
goto next;
if (asprintf(&p, "%s/%s", path, info.path) < 0) {
ret = -ENOMEM;
break;
}
k = cg_is_empty(controller, p, ignore_self);
free(p);
if (k < 0) {
ret = k;
break;
} else if (k == 0) {
empty = false;
break;
}
next:
r = cgroup_walk_tree_next(0, &iterator, &info, level);
}
if (ret == 0) {
if (r == 0 || r == ECGEOF)
ret = !!empty;
else if (r == ECGOTHER && errno == ENOENT)
ret = -ESRCH;
else
ret = cg_translate_error(r, errno);
}
assert_se(cgroup_walk_tree_end(&iterator) == 0);
return ret;
}