./move.sh

1 files changed, 2274 insertions, 0 deletions

diff --git a/src/libbasic/cgroup-util.c b/src/libbasic/cgroup-util.c
new file mode 100644
index 0000000000..6ef00d51df
--- /dev/null
+++ b/src/libbasic/cgroup-util.c
@@ -0,0 +1,2274 @@
+/***
+  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 <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 "formats-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_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 (streq(de->d_name, ".") ||
+                    streq(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, bool sigcont, bool ignore_self, Set *s) {
+        _cleanup_set_free_ Set *allocated_set = NULL;
+        bool done = false;
+        int r, ret = 0;
+        pid_t my_pid;
+
+        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) {
+                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 (ignore_self && pid == my_pid)
+                                continue;
+
+                        if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid))
+                                continue;
+
+                        /* If we haven't killed this process yet, kill
+                         * it */
+                        if (kill(pid, sig) < 0) {
+                                if (ret >= 0 && errno != ESRCH)
+                                        ret = -errno;
+                        } else {
+                                if (sigcont && sig != SIGKILL)
+                                        (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, bool sigcont, bool ignore_self, bool rem, Set *s) {
+        _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, sigcont, ignore_self, s);
+
+        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, NULL);
+                free(fn);
+                if (!p)
+                        return -ENOMEM;
+
+                r = cg_kill_recursive(controller, p, sig, sigcont, ignore_self, rem, s);
+                if (r != 0 && ret >= 0)
+                        ret = r;
+        }
+
+        if (ret >= 0 && r < 0)
+                ret = r;
+
+        if (rem) {
+                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, bool ignore_self) {
+        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 (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,
+                bool ignore_self,
+                bool rem) {
+
+        _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, ignore_self);
+
+        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, NULL);
+                free(fn);
+                if (!p)
+                        return -ENOMEM;
+
+                r = cg_migrate_recursive(cfrom, p, cto, pto, ignore_self, rem);
+                if (r != 0 && ret >= 0)
+                        ret = r;
+        }
+
+        if (r < 0 && ret >= 0)
+                ret = r;
+
+        if (rem) {
+                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,
+                bool ignore_self,
+                bool rem) {
+
+        int r;
+
+        assert(cfrom);
+        assert(pfrom);
+        assert(cto);
+        assert(pto);
+
+        r = cg_migrate_recursive(cfrom, pfrom, cto, pto, ignore_self, rem);
+        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, ignore_self, rem);
+                        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. */
+
+        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, NULL);
+        else if (isempty(suffix))
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path, NULL);
+        else
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path, "/", suffix, NULL);
+        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, NULL);
+        if (!t)
+                return -ENOMEM;
+
+        *fs = t;
+        return 0;
+}
+
+int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
+        int unified, 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, NULL);
+                if (!t)
+                        return -ENOMEM;
+
+                *fs = path_kill_slashes(t);
+                return 0;
+        }
+
+        if (!cg_controller_is_valid(controller))
+                return -EINVAL;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+
+        if (unified > 0)
+                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) {
+        int unified;
+
+        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;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0) {
+                /* 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, unified;
+
+        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;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified)
+                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_pid_get_path(const char *controller, pid_t pid, char **path) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char line[LINE_MAX];
+        const char *fs;
+        size_t cs = 0;
+        int unified;
+
+        assert(path);
+        assert(pid >= 0);
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified == 0) {
+                if (controller) {
+                        if (!cg_controller_is_valid(controller))
+                                return -EINVAL;
+                } else
+                        controller = SYSTEMD_CGROUP_CONTROLLER;
+
+                cs = strlen(controller);
+        }
+
+        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, 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, unified;
+
+        assert(agent);
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified) /* 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, unified;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified) /* 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 unified, r;
+
+        assert(path);
+
+        /* The root cgroup is always populated */
+        if (controller && (isempty(path) || path_equal(path, "/")))
+                return false;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+
+        if (unified > 0) {
+                _cleanup_free_ char *populated = NULL, *t = NULL;
+
+                /* On the unified hierarchy we can check empty state
+                 * via the "cgroup.populated" attribute. */
+
+                r = cg_get_path(controller, path, "cgroup.populated", &populated);
+                if (r < 0)
+                        return r;
+
+                r = read_one_line_file(populated, &t);
+                if (r == -ENOENT)
+                        return 1;
+                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, NULL);
+                        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("-.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;
+
+        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, "-.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_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) {
+        CGroupController c;
+        int r, unified;
+
+        /* 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 */
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0)
+                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, unified;
+
+        r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
+        if (r < 0)
+                return r;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0)
+                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, unified;
+
+        if (!path_equal(from, to))  {
+                r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true);
+                if (r < 0)
+                        return r;
+        }
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0)
+                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, false, false);
+        }
+
+        return 0;
+}
+
+int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) {
+        CGroupController c;
+        int r, unified;
+
+        r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
+        if (r < 0)
+                return r;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0)
+                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, unified;
+
+        /* Determines the mask of supported cgroup controllers. Only
+         * includes controllers we can make sense of and that are
+         * actually accessible. */
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (unified > 0) {
+                _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 only support the memory and pids
+                 * controller in the unified hierarchy, mask
+                 * everything else off. */
+                mask &= CGROUP_MASK_MEMORY | 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 int unified_cache = -1;
+
+int cg_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 >= 0)
+                return unified_cache;
+
+        if (statfs("/sys/fs/cgroup/", &fs) < 0)
+                return -errno;
+
+        if (F_TYPE_EQUAL(fs.f_type, CGROUP_SUPER_MAGIC))
+                unified_cache = true;
+        else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC))
+                unified_cache = false;
+        else
+                return -ENOMEDIUM;
+
+        return unified_cache;
+}
+
+void cg_unified_flush(void) {
+        unified_cache = -1;
+}
+
+int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
+        _cleanup_free_ char *fs = NULL;
+        CGroupController c;
+        int r, unified;
+
+        assert(p);
+
+        if (supported == 0)
+                return 0;
+
+        unified = cg_unified();
+        if (unified < 0)
+                return unified;
+        if (!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, unified;
+
+        /* If the hierarchy is already mounted, then follow whatever
+         * was chosen for it. */
+        unified = cg_unified();
+        if (unified >= 0)
+                return 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 = get_proc_cmdline_key("systemd.unified_cgroup_hierarchy", NULL);
+        if (r > 0)
+                return (wanted = true);
+        else {
+                _cleanup_free_ char *value = NULL;
+
+                r = get_proc_cmdline_key("systemd.unified_cgroup_hierarchy=", &value);
+                if (r < 0)
+                        return false;
+                if (r == 0)
+                        return (wanted = false);
+
+                return (wanted = parse_boolean(value) > 0);
+        }
+}
+
+bool cg_is_legacy_wanted(void) {
+        return !cg_is_unified_wanted();
+}
+
+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;
+}
+
+static const char *cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = {
+        [CGROUP_CONTROLLER_CPU] = "cpu",
+        [CGROUP_CONTROLLER_CPUACCT] = "cpuacct",
+        [CGROUP_CONTROLLER_BLKIO] = "blkio",
+        [CGROUP_CONTROLLER_MEMORY] = "memory",
+        [CGROUP_CONTROLLER_DEVICES] = "devices",
+        [CGROUP_CONTROLLER_PIDS] = "pids",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController);