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Systemd/src/login/logind-machine.c
Lennart Poettering 4ad490007b core: general cgroup rework 
Replace the very generic cgroup hookup with a much simpler one. With
this change only the high-level cgroup settings remain, the ability to
set arbitrary cgroup attributes is removed, so is support for adding
units to arbitrary cgroup controllers or setting arbitrary paths for
them (especially paths that are different for the various controllers).

This also introduces a new -.slice root slice, that is the parent of
system.slice and friends. This enables easy admin configuration of
root-level cgrouo properties.

This replaces DeviceDeny= by DevicePolicy=, and implicitly adds in
/dev/null, /dev/zero and friends if DeviceAllow= is used (unless this is
turned off by DevicePolicy=).
2013-06-27 04:17:34 +02:00

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 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 <string.h>
#include <unistd.h>
#include <errno.h>
#include "logind-machine.h"
#include "util.h"
#include "mkdir.h"
#include "cgroup-util.h"
#include "hashmap.h"
#include "strv.h"
#include "fileio.h"
#include "special.h"
#include <systemd/sd-messages.h>
Machine* machine_new(Manager *manager, const char *name) {
Machine *m;
assert(manager);
assert(name);
m = new0(Machine, 1);
if (!m)
return NULL;
m->name = strdup(name);
if (!m->name)
goto fail;
m->state_file = strappend("/run/systemd/machines/", m->name);
if (!m->state_file)
goto fail;
if (hashmap_put(manager->machines, m->name, m) < 0)
goto fail;
m->class = _MACHINE_CLASS_INVALID;
m->manager = manager;
return m;
fail:
free(m->state_file);
free(m->name);
free(m);
return NULL;
}
void machine_free(Machine *m) {
assert(m);
if (m->in_gc_queue)
LIST_REMOVE(Machine, gc_queue, m->manager->machine_gc_queue, m);
if (m->cgroup_path) {
hashmap_remove(m->manager->machine_cgroups, m->cgroup_path);
free(m->cgroup_path);
}
hashmap_remove(m->manager->machines, m->name);
free(m->name);
free(m->state_file);
free(m->service);
free(m->slice);
free(m->root_directory);
free(m);
}
int machine_save(Machine *m) {
_cleanup_free_ char *temp_path = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(m);
assert(m->state_file);
if (!m->started)
return 0;
r = mkdir_safe_label("/run/systemd/machines", 0755, 0, 0);
if (r < 0)
goto finish;
r = fopen_temporary(m->state_file, &f, &temp_path);
if (r < 0)
goto finish;
fchmod(fileno(f), 0644);
fprintf(f,
"# This is private data. Do not parse.\n"
"NAME=%s\n",
m->name);
if (m->cgroup_path)
fprintf(f, "CGROUP=%s\n", m->cgroup_path);
if (m->service)
fprintf(f, "SERVICE=%s\n", m->service);
if (m->slice)
fprintf(f, "SLICE=%s\n", m->slice);
if (m->root_directory)
fprintf(f, "ROOT=%s\n", m->root_directory);
if (!sd_id128_equal(m->id, SD_ID128_NULL))
fprintf(f, "ID=" SD_ID128_FORMAT_STR "\n", SD_ID128_FORMAT_VAL(m->id));
if (m->leader != 0)
fprintf(f, "LEADER=%lu\n", (unsigned long) m->leader);
if (m->class != _MACHINE_CLASS_INVALID)
fprintf(f, "CLASS=%s\n", machine_class_to_string(m->class));
if (dual_timestamp_is_set(&m->timestamp))
fprintf(f,
"REALTIME=%llu\n"
"MONOTONIC=%llu\n",
(unsigned long long) m->timestamp.realtime,
(unsigned long long) m->timestamp.monotonic);
fflush(f);
if (ferror(f) || rename(temp_path, m->state_file) < 0) {
r = -errno;
unlink(m->state_file);
unlink(temp_path);
}
finish:
if (r < 0)
log_error("Failed to save machine data for %s: %s", m->name, strerror(-r));
return r;
}
int machine_load(Machine *m) {
_cleanup_free_ char *realtime = NULL, *monotonic = NULL, *id = NULL, *leader = NULL, *class = NULL;
int r;
assert(m);
r = parse_env_file(m->state_file, NEWLINE,
"CGROUP", &m->cgroup_path,
"SERVICE", &m->service,
"SLICE", &m->slice,
"ROOT", &m->root_directory,
"ID", &id,
"LEADER", &leader,
"CLASS", &class,
"REALTIME", &realtime,
"MONOTONIC", &monotonic,
NULL);
if (r < 0) {
if (r == -ENOENT)
return 0;
log_error("Failed to read %s: %s", m->state_file, strerror(-r));
return r;
}
if (id)
sd_id128_from_string(id, &m->id);
if (leader)
parse_pid(leader, &m->leader);
if (class) {
MachineClass c;
c = machine_class_from_string(class);
if (c >= 0)
m->class = c;
}
if (realtime) {
unsigned long long l;
if (sscanf(realtime, "%llu", &l) > 0)
m->timestamp.realtime = l;
}
if (monotonic) {
unsigned long long l;
if (sscanf(monotonic, "%llu", &l) > 0)
m->timestamp.monotonic = l;
}
return r;
}
static int machine_create_one_group(Machine *m, const char *controller, const char *path) {
int r;
assert(m);
assert(path);
if (m->leader > 0)
r = cg_create_and_attach(controller, path, m->leader);
else
r = -EINVAL;
if (r < 0) {
r = cg_create(controller, path);
if (r < 0)
return r;
}
return 0;
}
static int machine_create_cgroup(Machine *m) {
char **k;
int r;
assert(m);
if (!m->slice) {
m->slice = strdup(SPECIAL_MACHINE_SLICE);
if (!m->slice)
return log_oom();
}
if (!m->cgroup_path) {
_cleanup_free_ char *escaped = NULL, *slice = NULL;
char *name;
name = strappenda(m->name, ".machine");
escaped = cg_escape(name);
if (!escaped)
return log_oom();
r = cg_slice_to_path(m->slice, &slice);
if (r < 0)
return r;
m->cgroup_path = strjoin(m->manager->cgroup_root, "/", slice, "/", escaped, NULL);
if (!m->cgroup_path)
return log_oom();
}
r = machine_create_one_group(m, SYSTEMD_CGROUP_CONTROLLER, m->cgroup_path);
if (r < 0) {
log_error("Failed to create cgroup "SYSTEMD_CGROUP_CONTROLLER":%s: %s", m->cgroup_path, strerror(-r));
return r;
}
STRV_FOREACH(k, m->manager->controllers) {
if (strv_contains(m->manager->reset_controllers, *k))
continue;
r = machine_create_one_group(m, *k, m->cgroup_path);
if (r < 0)
log_warning("Failed to create cgroup %s:%s: %s", *k, m->cgroup_path, strerror(-r));
}
if (m->leader > 0) {
STRV_FOREACH(k, m->manager->reset_controllers) {
r = cg_attach(*k, "/", m->leader);
if (r < 0)
log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
}
}
r = hashmap_put(m->manager->machine_cgroups, m->cgroup_path, m);
if (r < 0)
log_warning("Failed to create mapping between cgroup and machine");
return 0;
}
int machine_start(Machine *m) {
int r;
assert(m);
if (m->started)
return 0;
log_struct(LOG_INFO,
MESSAGE_ID(SD_MESSAGE_MACHINE_START),
"NAME=%s", m->name,
"LEADER=%lu", (unsigned long) m->leader,
"MESSAGE=New machine %s.", m->name,
NULL);
/* Create cgroup */
r = machine_create_cgroup(m);
if (r < 0)
return r;
if (!dual_timestamp_is_set(&m->timestamp))
dual_timestamp_get(&m->timestamp);
m->started = true;
/* Save new machine data */
machine_save(m);
machine_send_signal(m, true);
return 0;
}
static int machine_terminate_cgroup(Machine *m) {
int r;
char **k;
assert(m);
if (!m->cgroup_path)
return 0;
cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_path, false);
r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_path, true);
if (r < 0)
log_error("Failed to kill machine cgroup: %s", strerror(-r));
STRV_FOREACH(k, m->manager->controllers)
cg_trim(*k, m->cgroup_path, true);
hashmap_remove(m->manager->machine_cgroups, m->cgroup_path);
free(m->cgroup_path);
m->cgroup_path = NULL;
return r;
}
int machine_stop(Machine *m) {
int r = 0, k;
assert(m);
if (m->started)
log_struct(LOG_INFO,
MESSAGE_ID(SD_MESSAGE_MACHINE_STOP),
"NAME=%s", m->name,
"LEADER=%lu", (unsigned long) m->leader,
"MESSAGE=Machine %s terminated.", m->name,
NULL);
/* Kill cgroup */
k = machine_terminate_cgroup(m);
if (k < 0)
r = k;
unlink(m->state_file);
machine_add_to_gc_queue(m);
if (m->started)
machine_send_signal(m, false);
m->started = false;
return r;
}
int machine_check_gc(Machine *m, bool drop_not_started) {
int r;
assert(m);
if (drop_not_started && !m->started)
return 0;
if (m->cgroup_path) {
r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_path, false);
if (r < 0)
return r;
if (r <= 0)
return 1;
}
return 0;
}
void machine_add_to_gc_queue(Machine *m) {
assert(m);
if (m->in_gc_queue)
return;
LIST_PREPEND(Machine, gc_queue, m->manager->machine_gc_queue, m);
m->in_gc_queue = true;
}
int machine_kill(Machine *m, KillWho who, int signo) {
_cleanup_set_free_ Set *pid_set = NULL;
int r = 0;
assert(m);
if (!m->cgroup_path)
return -ESRCH;
if (m->leader <= 0 && who == KILL_LEADER)
return -ESRCH;
if (m->leader > 0)
if (kill(m->leader, signo) < 0)
r = -errno;
if (who == KILL_ALL) {
int q;
pid_set = set_new(trivial_hash_func, trivial_compare_func);
if (!pid_set)
return log_oom();
if (m->leader > 0) {
q = set_put(pid_set, LONG_TO_PTR(m->leader));
if (q < 0)
r = q;
}
q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_path, signo, false, true, false, pid_set);
if (q < 0 && (q != -EAGAIN && q != -ESRCH && q != -ENOENT))
r = q;
}
return r;
}
static const char* const machine_class_table[_MACHINE_CLASS_MAX] = {
[MACHINE_CONTAINER] = "container",
[MACHINE_VM] = "vm"
};
DEFINE_STRING_TABLE_LOOKUP(machine_class, MachineClass);
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