163 lines
5.8 KiB
C
163 lines
5.8 KiB
C
/***
|
|
This file is part of systemd.
|
|
|
|
Copyright 2015 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 <sys/mount.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "cgroup-util.h"
|
|
#include "fd-util.h"
|
|
#include "fileio.h"
|
|
#include "mkdir.h"
|
|
#include "nspawn-cgroup.h"
|
|
#include "string-util.h"
|
|
#include "strv.h"
|
|
#include "util.h"
|
|
|
|
int chown_cgroup(pid_t pid, uid_t uid_shift) {
|
|
_cleanup_free_ char *path = NULL, *fs = NULL;
|
|
_cleanup_close_ int fd = -1;
|
|
const char *fn;
|
|
int r;
|
|
|
|
r = cg_pid_get_path(NULL, pid, &path);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to get container cgroup path: %m");
|
|
|
|
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to get file system path for container cgroup: %m");
|
|
|
|
fd = open(fs, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
|
|
if (fd < 0)
|
|
return log_error_errno(errno, "Failed to open %s: %m", fs);
|
|
|
|
FOREACH_STRING(fn,
|
|
".",
|
|
"tasks",
|
|
"notify_on_release",
|
|
"cgroup.procs",
|
|
"cgroup.events",
|
|
"cgroup.clone_children",
|
|
"cgroup.controllers",
|
|
"cgroup.subtree_control")
|
|
if (fchownat(fd, fn, uid_shift, uid_shift, 0) < 0)
|
|
log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno,
|
|
"Failed to chown() cgroup file %s, ignoring: %m", fn);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int sync_cgroup(pid_t pid, bool unified_requested) {
|
|
_cleanup_free_ char *cgroup = NULL;
|
|
char tree[] = "/tmp/unifiedXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1];
|
|
bool undo_mount = false;
|
|
const char *fn;
|
|
int unified, r;
|
|
|
|
unified = cg_unified();
|
|
if (unified < 0)
|
|
return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
|
|
|
|
if ((unified > 0) == unified_requested)
|
|
return 0;
|
|
|
|
/* When the host uses the legacy cgroup setup, but the
|
|
* container shall use the unified hierarchy, let's make sure
|
|
* we copy the path from the name=systemd hierarchy into the
|
|
* unified hierarchy. Similar for the reverse situation. */
|
|
|
|
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid);
|
|
|
|
/* In order to access the unified hierarchy we need to mount it */
|
|
if (!mkdtemp(tree))
|
|
return log_error_errno(errno, "Failed to generate temporary mount point for unified hierarchy: %m");
|
|
|
|
if (unified)
|
|
r = mount("cgroup", tree, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr");
|
|
else
|
|
r = mount("cgroup", tree, "cgroup2", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
|
|
if (r < 0) {
|
|
r = log_error_errno(errno, "Failed to mount unified hierarchy: %m");
|
|
goto finish;
|
|
}
|
|
|
|
undo_mount = true;
|
|
|
|
fn = strjoina(tree, cgroup, "/cgroup.procs");
|
|
(void) mkdir_parents(fn, 0755);
|
|
|
|
sprintf(pid_string, PID_FMT, pid);
|
|
r = write_string_file(fn, pid_string, 0);
|
|
if (r < 0)
|
|
log_error_errno(r, "Failed to move process: %m");
|
|
|
|
finish:
|
|
if (undo_mount)
|
|
(void) umount(tree);
|
|
|
|
(void) rmdir(tree);
|
|
return r;
|
|
}
|
|
|
|
int create_subcgroup(pid_t pid, bool unified_requested) {
|
|
_cleanup_free_ char *cgroup = NULL;
|
|
const char *child;
|
|
int unified, r;
|
|
CGroupMask supported;
|
|
|
|
/* In the unified hierarchy inner nodes may only contain
|
|
* subgroups, but not processes. Hence, if we running in the
|
|
* unified hierarchy and the container does the same, and we
|
|
* did not create a scope unit for the container move us and
|
|
* the container into two separate subcgroups. */
|
|
|
|
if (!unified_requested)
|
|
return 0;
|
|
|
|
unified = cg_unified();
|
|
if (unified < 0)
|
|
return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
|
|
if (unified == 0)
|
|
return 0;
|
|
|
|
r = cg_mask_supported(&supported);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to determine supported controllers: %m");
|
|
|
|
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to get our control group: %m");
|
|
|
|
child = strjoina(cgroup, "/payload");
|
|
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
|
|
|
|
child = strjoina(cgroup, "/supervisor");
|
|
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
|
|
|
|
/* Try to enable as many controllers as possible for the new payload. */
|
|
(void) cg_enable_everywhere(supported, supported, cgroup);
|
|
return 0;
|
|
}
|