src/libudev/cgroup-util.{c,h}: bring in line with upstream

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

4 files changed, 80 insertions, 1093 deletions

diff --git a/src/libudev/cgroup-util.c b/src/libudev/cgroup-util.c
index 19f9889c8a..a276bf1061 100644
--- a/src/libudev/cgroup-util.c
+++ b/src/libudev/cgroup-util.c
@@ -20,62 +20,27 @@
 ***/
 
 #include <errno.h>
-#include <unistd.h>
 #include <signal.h>
 #include <string.h>
 #include <stdlib.h>
-#include <dirent.h>
-#include <sys/stat.h>
 #include <sys/types.h>
-#include <ftw.h>
 
 #include "cgroup-util.h"
-#include "log.h"
 #include "set.h"
-#include "macro.h"
-#include "util.h"
 #include "path-util.h"
-#include "strv.h"
-
-static const char cgroup_path[] = "/sys/fs/cgroup/";
 
 int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
-        char *fs;
-        int r;
+        _cleanup_free_ char *fs = NULL;
         FILE *f;
-
-        assert(path);
-        assert(_f);
-
-        r = cg_get_path(controller, path, "cgroup.procs", &fs);
-        if (r < 0)
-                return r;
-
-        f = fopen(fs, "re");
-        free(fs);
-
-        if (!f)
-                return -errno;
-
-        *_f = f;
-        return 0;
-}
-
-int cg_enumerate_tasks(const char *controller, const char *path, FILE **_f) {
-        char *fs;
         int r;
-        FILE *f;
 
-        assert(path);
         assert(_f);
 
-        r = cg_get_path(controller, path, "tasks", &fs);
+        r = cg_get_path(controller, path, "cgroup.procs", &fs);
         if (r < 0)
                 return r;
 
         f = fopen(fs, "re");
-        free(fs);
-
         if (!f)
                 return -errno;
 
@@ -89,6 +54,9 @@ int cg_read_pid(FILE *f, pid_t *_pid) {
         /* 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) {
 
@@ -105,128 +73,42 @@ int cg_read_pid(FILE *f, pid_t *_pid) {
         return 1;
 }
 
-int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
-        char *fs;
-        int r;
-        DIR *d;
-
-        assert(path);
-        assert(_d);
-
-        /* This is not recursive! */
-
-        r = cg_get_path(controller, path, NULL, &fs);
-        if (r < 0)
-                return r;
-
-        d = opendir(fs);
-        free(fs);
-
-        if (!d)
-                return -errno;
-
-        *_d = d;
-        return 0;
-}
-
-int cg_read_subgroup(DIR *d, char **fn) {
-        struct dirent *de;
-
-        assert(d);
-
-        errno = 0;
-        while ((de = readdir(d))) {
-                char *b;
-
-                if (de->d_type != DT_DIR)
-                        continue;
-
-                if (streq(de->d_name, ".") ||
-                    streq(de->d_name, ".."))
-                        continue;
-
-                if (!(b = strdup(de->d_name)))
-                        return -ENOMEM;
-
-                *fn = b;
-                return 1;
-        }
-
-        if (errno)
-                return -errno;
-
-        return 0;
-}
-
-int cg_rmdir(const char *controller, const char *path, bool honour_sticky) {
-        char *p;
-        int r;
-
-        r = cg_get_path(controller, path, NULL, &p);
-        if (r < 0)
-                return r;
-
-        if (honour_sticky) {
-                char *tasks;
-
-                /* If the sticky bit is set don't remove the directory */
-
-                tasks = strappend(p, "/tasks");
-                if (!tasks) {
-                        free(p);
-                        return -ENOMEM;
-                }
-
-                r = file_is_priv_sticky(tasks);
-                free(tasks);
-
-                if (r > 0) {
-                        free(p);
-                        return 0;
-                }
-        }
-
-        r = rmdir(p);
-        free(p);
-
-        return (r < 0 && errno != ENOENT) ? -errno : 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;
-        FILE *f = NULL;
-        Set *allocated_set = NULL;
 
-        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)
-                if (!(s = allocated_set = set_new(trivial_hash_func, trivial_compare_func)))
+        if (!s) {
+                s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
+                if (!s)
                         return -ENOMEM;
+        }
 
         my_pid = getpid();
 
         do {
+                _cleanup_fclose_ FILE *f = NULL;
                 pid_t pid = 0;
                 done = true;
 
-                if ((r = cg_enumerate_processes(controller, path, &f)) < 0) {
+                r = cg_enumerate_processes(controller, path, &f);
+                if (r < 0) {
                         if (ret >= 0 && r != -ENOENT)
-                                ret = r;
+                                return r;
 
-                        goto finish;
+                        return ret;
                 }
 
                 while ((r = cg_read_pid(f, &pid)) > 0) {
 
-                        if (pid == my_pid && ignore_self)
+                        if (ignore_self && pid == my_pid)
                                 continue;
 
                         if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
@@ -247,266 +129,34 @@ int cg_kill(const char *controller, const char *path, int sig, bool sigcont, boo
 
                         done = false;
 
-                        if ((r = set_put(s, LONG_TO_PTR(pid))) < 0) {
+                        r = set_put(s, LONG_TO_PTR(pid));
+                        if (r < 0) {
                                 if (ret >= 0)
-                                        ret = r;
+                                        return r;
 
-                                goto finish;
+                                return ret;
                         }
                 }
 
                 if (r < 0) {
                         if (ret >= 0)
-                                ret = r;
+                                return r;
 
-                        goto finish;
+                        return ret;
                 }
 
-                fclose(f);
-                f = NULL;
-
                 /* 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);
 
-finish:
-        if (allocated_set)
-                set_free(allocated_set);
-
-        if (f)
-                fclose(f);
-
-        return ret;
-}
-
-int cg_kill_recursive(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, bool rem, Set *s) {
-        int r, ret = 0;
-        DIR *d = NULL;
-        char *fn;
-        Set *allocated_set = NULL;
-
-        assert(path);
-        assert(controller);
-        assert(sig >= 0);
-
-        if (!s)
-                if (!(s = allocated_set = set_new(trivial_hash_func, trivial_compare_func)))
-                        return -ENOMEM;
-
-        ret = cg_kill(controller, path, sig, sigcont, ignore_self, s);
-
-        if ((r = cg_enumerate_subgroups(controller, path, &d)) < 0) {
-                if (ret >= 0 && r != -ENOENT)
-                        ret = r;
-
-                goto finish;
-        }
-
-        while ((r = cg_read_subgroup(d, &fn)) > 0) {
-                char *p = NULL;
-
-                r = asprintf(&p, "%s/%s", path, fn);
-                free(fn);
-
-                if (r < 0) {
-                        if (ret >= 0)
-                                ret = -ENOMEM;
-
-                        goto finish;
-                }
-
-                r = cg_kill_recursive(controller, p, sig, sigcont, ignore_self, rem, s);
-                free(p);
-
-                if (r != 0 && ret >= 0)
-                        ret = r;
-        }
-
-        if (r < 0 && ret >= 0)
-                ret = r;
-
-        if (rem)
-                if ((r = cg_rmdir(controller, path, true)) < 0) {
-                        if (ret >= 0 &&
-                            r != -ENOENT &&
-                            r != -EBUSY)
-                                ret = r;
-                }
-
-finish:
-        if (d)
-                closedir(d);
-
-        if (allocated_set)
-                set_free(allocated_set);
-
         return ret;
 }
 
-int cg_kill_recursive_and_wait(const char *controller, const char *path, bool rem) {
-        unsigned i;
-
-        assert(path);
-        assert(controller);
-
-        /* This safely kills all processes; first it sends a SIGTERM,
-         * then checks 8 times after 200ms whether the group is now
-         * empty, then kills everything that is left with SIGKILL and
-         * finally checks 5 times after 200ms each whether the group
-         * is finally empty. */
-
-        for (i = 0; i < 15; 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, true, rem, NULL)) <= 0)
-                        return r;
-
-                usleep(200 * USEC_PER_MSEC);
-        }
-
-        return 0;
-}
-
-int cg_migrate(const char *controller, const char *from, const char *to, bool ignore_self) {
-        bool done = false;
-        Set *s;
-        int r, ret = 0;
-        pid_t my_pid;
-        FILE *f = NULL;
-
-        assert(controller);
-        assert(from);
-        assert(to);
-
-        if (!(s = set_new(trivial_hash_func, trivial_compare_func)))
-                return -ENOMEM;
-
-        my_pid = getpid();
-
-        do {
-                pid_t pid = 0;
-                done = true;
-
-                if ((r = cg_enumerate_tasks(controller, from, &f)) < 0) {
-                        if (ret >= 0 && r != -ENOENT)
-                                ret = r;
-
-                        goto finish;
-                }
-
-                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 (pid == my_pid && ignore_self)
-                                continue;
-
-                        if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
-                                continue;
-
-                        if ((r = cg_attach(controller, to, pid)) < 0) {
-                                if (ret >= 0 && r != -ESRCH)
-                                        ret = r;
-                        } else if (ret == 0)
-                                ret = 1;
-
-                        done = false;
-
-                        if ((r = set_put(s, LONG_TO_PTR(pid))) < 0) {
-                                if (ret >= 0)
-                                        ret = r;
-
-                                goto finish;
-                        }
-                }
-
-                if (r < 0) {
-                        if (ret >= 0)
-                                ret = r;
-
-                        goto finish;
-                }
-
-                fclose(f);
-                f = NULL;
-
-        } while (!done);
-
-finish:
-        set_free(s);
-
-        if (f)
-                fclose(f);
-
-        return ret;
-}
-
-int cg_migrate_recursive(const char *controller, const char *from, const char *to, bool ignore_self, bool rem) {
-        int r, ret = 0;
-        DIR *d = NULL;
-        char *fn;
+static const char *normalize_controller(const char *controller) {
 
         assert(controller);
-        assert(from);
-        assert(to);
-
-        ret = cg_migrate(controller, from, to, ignore_self);
-
-        if ((r = cg_enumerate_subgroups(controller, from, &d)) < 0) {
-                if (ret >= 0 && r != -ENOENT)
-                        ret = r;
-                goto finish;
-        }
-
-        while ((r = cg_read_subgroup(d, &fn)) > 0) {
-                char *p = NULL;
-
-                r = asprintf(&p, "%s/%s", from, fn);
-                free(fn);
-
-                if (r < 0) {
-                        if (ret >= 0)
-                                ret = -ENOMEM;
-
-                        goto finish;
-                }
-
-                r = cg_migrate_recursive(controller, p, to, ignore_self, rem);
-                free(p);
-
-                if (r != 0 && ret >= 0)
-                        ret = r;
-        }
-
-        if (r < 0 && ret >= 0)
-                ret = r;
-
-        if (rem)
-                if ((r = cg_rmdir(controller, from, true)) < 0) {
-                        if (ret >= 0 &&
-                            r != -ENOENT &&
-                            r != -EBUSY)
-                                ret = r;
-                }
-
-finish:
-        if (d)
-                closedir(d);
-
-        return ret;
-}
-
-static const char *normalize_controller(const char *controller) {
 
         if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
                 return "systemd";
@@ -519,23 +169,22 @@ static const char *normalize_controller(const char *controller) {
 static int join_path(const char *controller, const char *path, const char *suffix, char **fs) {
         char *t = NULL;
 
-        if (!(controller || path))
-                return -EINVAL;
-
         if (controller) {
                 if (path && suffix)
-                        t = strjoin(cgroup_path, controller, "/", path, "/", suffix, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
                 else if (path)
-                        t = strjoin(cgroup_path, controller, "/", path, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL);
                 else if (suffix)
-                        t = strjoin(cgroup_path, controller, "/", suffix, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL);
                 else
-                        t = strjoin(cgroup_path, controller, NULL);
+                        t = strappend("/sys/fs/cgroup/", controller);
         } else {
                 if (path && suffix)
                         t = strjoin(path, "/", suffix, NULL);
                 else if (path)
                         t = strdup(path);
+                else
+                        return -EINVAL;
         }
 
         if (!t)
@@ -553,6 +202,9 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
 
         assert(fs);
 
+        if (controller && !cg_controller_is_valid(controller, true))
+                return -EINVAL;
+
         if (_unlikely_(!good)) {
                 int r;
 
@@ -565,694 +217,38 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         }
 
         p = controller ? normalize_controller(controller) : NULL;
-        return join_path(p, path, suffix, fs);
-}
-
-static int check(const char *p) {
-        char *cc;
-
-        assert(p);
-
-        /* Check if this controller actually really exists */
-        cc = alloca(sizeof(cgroup_path) + strlen(p));
-        strcpy(stpcpy(cc, cgroup_path), p);
-        if (access(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) {
-        const char *p;
-        int r;
-
-        assert(controller);
-        assert(fs);
-
-        if (isempty(controller))
-                return -EINVAL;
-
-        /* Normalize the controller syntax */
-        p = normalize_controller(controller);
-
-        /* Check if this controller actually really exists */
-        r = check(p);
-        if (r < 0)
-                return r;
 
         return join_path(p, path, suffix, fs);
 }
 
-static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
-        char *p;
-        bool is_sticky;
-
-        if (typeflag != FTW_DP)
-                return 0;
-
-        if (ftwbuf->level < 1)
-                return 0;
-
-        p = strappend(path, "/tasks");
-        if (!p) {
-                errno = ENOMEM;
-                return 1;
-        }
-
-        is_sticky = file_is_priv_sticky(p) > 0;
-        free(p);
-
-        if (is_sticky)
-                return 0;
-
-        rmdir(path);
-        return 0;
-}
-
-int cg_trim(const char *controller, const char *path, bool delete_root) {
-        char *fs;
-        int r = 0;
-
-        assert(controller);
-        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)
-                r = errno ? -errno : -EIO;
-
-        if (delete_root) {
-                bool is_sticky;
-                char *p;
 
-                p = strappend(fs, "/tasks");
-                if (!p) {
-                        free(fs);
-                        return -ENOMEM;
-                }
+#define CONTROLLER_VALID                        \
+        "0123456789"                            \
+        "abcdefghijklmnopqrstuvwxyz"            \
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
+        "_"
 
-                is_sticky = file_is_priv_sticky(p) > 0;
-                free(p);
-
-                if (!is_sticky)
-                        if (rmdir(fs) < 0 && errno != ENOENT) {
-                                if (r == 0)
-                                        r = -errno;
-                        }
-        }
-
-        free(fs);
-
-        return r;
-}
-
-int cg_delete(const char *controller, const char *path) {
-        char *parent;
-        int r;
-
-        assert(controller);
-        assert(path);
-
-        if ((r = path_get_parent(path, &parent)) < 0)
-                return r;
-
-        r = cg_migrate_recursive(controller, path, parent, false, true);
-        free(parent);
-
-        return r == -ENOENT ? 0 : r;
-}
-
-int cg_attach(const char *controller, const char *path, pid_t pid) {
-        char *fs;
-        int r;
-        char c[32];
-
-        assert(controller);
-        assert(path);
-        assert(pid >= 0);
-
-        r = cg_get_path_and_check(controller, path, "tasks", &fs);
-        if (r < 0)
-                return r;
-
-        if (pid == 0)
-                pid = getpid();
-
-        snprintf(c, sizeof(c), "%lu\n", (unsigned long) pid);
-        char_array_0(c);
-
-        r = write_one_line_file(fs, c);
-        free(fs);
-
-        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 (mode != (mode_t) -1)
-                mode &= 0777;
-
-        r = cg_get_path(controller, path, NULL, &fs);
-        if (r < 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, int sticky) {
-        char *fs;
-        int r;
-
-        assert(controller);
-        assert(path);
-
-        if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1 && sticky < 0)
-                return 0;
-
-        if (mode != (mode_t) -1)
-                mode &= 0666;
-
-        r = cg_get_path(controller, path, "tasks", &fs);
-        if (r < 0)
-                return r;
-
-        if (sticky >= 0 && mode != (mode_t) -1)
-                /* Both mode and sticky param are passed */
-                mode |= (sticky ? S_ISVTX : 0);
-        else if ((sticky >= 0 && mode == (mode_t) -1) ||
-                 (mode != (mode_t) -1 && sticky < 0)) {
-                struct stat st;
-
-                /* Only one param is passed, hence read the current
-                 * mode from the file itself */
-
-                r = lstat(fs, &st);
-                if (r < 0) {
-                        free(fs);
-                        return -errno;
-                }
-
-                if (mode == (mode_t) -1)
-                        /* No mode set, we just shall set the sticky bit */
-                        mode = (st.st_mode & ~S_ISVTX) | (sticky ? S_ISVTX : 0);
-                else
-                        /* Only mode set, leave sticky bit untouched */
-                        mode = (st.st_mode & ~0777) | mode;
-        }
-
-        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;
-        FILE *f;
-        char *fs;
-        size_t cs;
-
-        assert(controller);
-        assert(path);
-        assert(pid >= 0);
-
-        if (pid == 0)
-                pid = getpid();
-
-        if (asprintf(&fs, "/proc/%lu/cgroup", (unsigned long) pid) < 0)
-                return -ENOMEM;
-
-        f = fopen(fs, "re");
-        free(fs);
-
-        if (!f)
-                return errno == ENOENT ? -ESRCH : -errno;
-
-        cs = strlen(controller);
-
-        while (!feof(f)) {
-                char line[LINE_MAX];
-                char *l;
-
-                errno = 0;
-                if (!(fgets(line, sizeof(line), f))) {
-                        if (feof(f))
-                                break;
-
-                        r = errno ? -errno : -EIO;
-                        goto finish;
-                }
-
-                truncate_nl(line);
-
-                if (!(l = strchr(line, ':')))
-                        continue;
-
-                l++;
-                if (strncmp(l, controller, cs) != 0)
-                        continue;
-
-                if (l[cs] != ':')
-                        continue;
-
-                if (!(p = strdup(l + cs + 1))) {
-                        r = -ENOMEM;
-                        goto finish;
-                }
-
-                *path = p;
-                r = 0;
-                goto finish;
-        }
-
-        r = -ENOENT;
-
-finish:
-        fclose(f);
-
-        return r;
-}
-
-int cg_install_release_agent(const char *controller, const char *agent) {
-        char *fs = NULL, *contents = NULL, *line = NULL, *sc;
-        int r;
-
-        assert(controller);
-        assert(agent);
-
-        if ((r = cg_get_path(controller, NULL, "release_agent", &fs)) < 0)
-                return r;
-
-        if ((r = read_one_line_file(fs, &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(fs, line)) < 0)
-                        goto finish;
-
-        } else if (!streq(sc, agent)) {
-                r = -EEXIST;
-                goto finish;
-        }
-
-        free(fs);
-        fs = NULL;
-        if ((r = cg_get_path(controller, NULL, "notify_on_release", &fs)) < 0)
-                goto finish;
-
-        free(contents);
-        contents = NULL;
-        if ((r = read_one_line_file(fs, &contents)) < 0)
-                goto finish;
-
-        sc = strstrip(contents);
-
-        if (streq(sc, "0")) {
-                if ((r = write_one_line_file(fs, "1\n")) < 0)
-                        goto finish;
-
-                r = 1;
-        } else if (!streq(sc, "1")) {
-                r = -EIO;
-                goto finish;
-        } else
-                r = 0;
-
-finish:
-        free(fs);
-        free(contents);
-        free(line);
-
-        return r;
-}
-
-int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
-        pid_t pid = 0, self_pid;
-        int r;
-        FILE *f = NULL;
-        bool found = false;
-
-        assert(path);
-
-        r = cg_enumerate_tasks(controller, path, &f);
-        if (r < 0)
-                return r == -ENOENT ? 1 : r;
-
-        self_pid = getpid();
-
-        while ((r = cg_read_pid(f, &pid)) > 0) {
-
-                if (ignore_self && pid == self_pid)
-                        continue;
-
-                found = true;
-                break;
-        }
-
-        fclose(f);
-
-        if (r < 0)
-                return r;
-
-        return !found;
-}
-
-int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
-        int r;
-        DIR *d = NULL;
-        char *fn;
-
-        assert(path);
-
-        r = cg_is_empty(controller, path, ignore_self);
-        if (r <= 0)
-                return r;
-
-        r = cg_enumerate_subgroups(controller, path, &d);
-        if (r < 0)
-                return r == -ENOENT ? 1 : r;
-
-        while ((r = cg_read_subgroup(d, &fn)) > 0) {
-                char *p = NULL;
-
-                r = asprintf(&p, "%s/%s", path, fn);
-                free(fn);
-
-                if (r < 0) {
-                        r = -ENOMEM;
-                        goto finish;
-                }
-
-                r = cg_is_empty_recursive(controller, p, ignore_self);
-                free(p);
-
-                if (r <= 0)
-                        goto finish;
-        }
-
-        if (r >= 0)
-                r = 1;
-
-finish:
-
-        if (d)
-                closedir(d);
-
-        return r;
-}
-
-int cg_split_spec(const char *spec, char **controller, char **path) {
-        const char *e;
-        char *t = NULL, *u = NULL;
-
-        assert(spec);
-        assert(controller || path);
-
-        if (*spec == '/') {
-
-                if (path) {
-                        if (!(t = strdup(spec)))
-                                return -ENOMEM;
-
-                        *path = t;
-                }
-
-                if (controller)
-                        *controller = NULL;
-
-                return 0;
-        }
-
-        if (!(e = strchr(spec, ':'))) {
-
-                if (strchr(spec, '/') || spec[0] == 0)
-                        return -EINVAL;
-
-                if (controller) {
-                        if (!(t = strdup(spec)))
-                                return -ENOMEM;
-
-                        *controller = t;
-                }
-
-                if (path)
-                        *path = NULL;
-
-                return 0;
-        }
-
-        if (e[1] != '/' ||
-            e == spec ||
-            memchr(spec, '/', e-spec))
-                return -EINVAL;
-
-        if (controller)
-                if (!(t = strndup(spec, e-spec)))
-                        return -ENOMEM;
-
-        if (path)
-                if (!(u = strdup(e+1))) {
-                        free(t);
-                        return -ENOMEM;
-                }
-
-        if (controller)
-                *controller = t;
-
-        if (path)
-                *path = u;
-
-        return 0;
-}
-
-int cg_join_spec(const char *controller, const char *path, char **spec) {
-        assert(controller);
-        assert(path);
-
-        if (!path_is_absolute(path) ||
-            controller[0] == 0 ||
-            strchr(controller, ':') ||
-            strchr(controller, '/'))
-                return -EINVAL;
-
-        if (asprintf(spec, "%s:%s", controller, path) < 0)
-                return -ENOMEM;
-
-        return 0;
-}
-
-int cg_fix_path(const char *path, char **result) {
-        char *t, *c, *p;
-        int r;
-
-        assert(path);
-        assert(result);
-
-        /* First check if it already is a filesystem path */
-        if (path_startswith(path, "/sys/fs/cgroup") &&
-            access(path, F_OK) >= 0) {
-
-                t = strdup(path);
-                if (!t)
-                        return -ENOMEM;
-
-                *result = t;
-                return 0;
-        }
-
-        /* Otherwise treat it as cg spec */
-        r = cg_split_spec(path, &c, &p);
-        if (r < 0)
-                return r;
-
-        r = cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
-        free(c);
-        free(p);
-
-        return r;
-}
-
-int cg_get_user_path(char **path) {
-        char *root, *p;
-
-        assert(path);
-
-        /* Figure out the place to put user cgroups below. We use the
-         * same as PID 1 has but with the "/system" suffix replaced by
-         * "/user" */
-
-        if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &root) < 0)
-                p = strdup("/user");
-        else {
-                if (endswith(root, "/system"))
-                        root[strlen(root) - 7] = 0;
-                else if (streq(root, "/"))
-                        root[0] = 0;
-
-                p = strappend(root, "/user");
-                free(root);
-        }
+bool cg_controller_is_valid(const char *p, bool allow_named) {
+        const char *t, *s;
 
         if (!p)
-                return -ENOMEM;
-
-        *path = p;
-        return 0;
-}
-
-char **cg_shorten_controllers(char **controllers) {
-        char **f, **t;
-
-        controllers = strv_uniq(controllers);
-
-        if (!controllers)
-                return controllers;
-
-        for (f = controllers, t = controllers; *f; f++) {
-                int r;
-                const char *p;
-
-                if (streq(*f, "systemd") || streq(*f, SYSTEMD_CGROUP_CONTROLLER)) {
-                        free(*f);
-                        continue;
-                }
-
-                p = normalize_controller(*f);
-
-                r = check(p);
-                if (r < 0) {
-                        log_debug("Controller %s is not available, removing from controllers list.", *f);
-                        free(*f);
-                        continue;
-                }
-
-                *(t++) = *f;
-        }
-
-        *t = NULL;
-        return controllers;
-}
-
-int cg_pid_get_cgroup(pid_t pid, char **root, char **cgroup) {
-        char *cg_process, *cg_init, *p;
-        int r;
-
-        assert(pid >= 0);
-
-        if (pid == 0)
-                pid = getpid();
-
-        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
-        if (r < 0)
-                return r;
-
-        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &cg_init);
-        if (r < 0) {
-                free(cg_process);
-                return r;
-        }
-
-        if (endswith(cg_init, "/system"))
-                cg_init[strlen(cg_init)-7] = 0;
-        else if (streq(cg_init, "/"))
-                cg_init[0] = 0;
-
-        if (startswith(cg_process, cg_init))
-                p = cg_process + strlen(cg_init);
-        else
-                p = cg_process;
-
-        free(cg_init);
-
-        if (cgroup) {
-                char* c;
-
-                c = strdup(p);
-                if (!c) {
-                        free(cg_process);
-                        return -ENOMEM;
-                }
+                return false;
 
-                *cgroup = c;
+        if (allow_named) {
+                s = startswith(p, "name=");
+                if (s)
+                        p = s;
         }
 
-        if (root) {
-                cg_process[p-cg_process] = 0;
-                *root = cg_process;
-        } else
-                free(cg_process);
-
-        return 0;
-}
-
-int cg_pid_get_unit(pid_t pid, char **unit) {
-        int r;
-        char *cgroup, *p, *at, *b;
-        size_t k;
+        if (*p == 0 || *p == '_')
+                return false;
 
-        assert(pid >= 0);
-        assert(unit);
+        for (t = p; *t; t++)
+                if (!strchr(CONTROLLER_VALID, *t))
+                        return false;
 
-        r = cg_pid_get_cgroup(pid, NULL, &cgroup);
-        if (r < 0)
-                return r;
-
-        if (!startswith(cgroup, "/system/")) {
-                free(cgroup);
-                return -ENOENT;
-        }
-
-        p = cgroup + 8;
-        k = strcspn(p, "/");
-
-        at = memchr(p, '@', k);
-        if (at && at[1] == '.') {
-                size_t j;
-
-                /* This is a templated service */
-                if (p[k] != '/') {
-                        free(cgroup);
-                        return -EIO;
-                }
-
-                j = strcspn(p+k+1, "/");
-
-                b = malloc(k + j + 1);
-
-                if (b) {
-                        memcpy(b, p, at - p + 1);
-                        memcpy(b + (at - p) + 1, p + k + 1, j);
-                        memcpy(b + (at - p) + 1 + j, at + 1, k - (at - p) - 1);
-                        b[k+j] = 0;
-                }
-        } else
-                  b = strndup(p, k);
-
-        free(cgroup);
-
-        if (!b)
-                return -ENOMEM;
-
-        *unit = b;
-        return 0;
+        if (t - p > FILENAME_MAX)
+                return false;
 
+        return true;
 }
diff --git a/src/libudev/cgroup-util.h b/src/libudev/cgroup-util.h
index 697669deba..11e7308e19 100644
--- a/src/libudev/cgroup-util.h
+++ b/src/libudev/cgroup-util.h
@@ -28,47 +28,26 @@
 #include "set.h"
 #include "def.h"
 
+/*
+ * General rules:
+ *
+ * We accept named hierarchies in the syntax "foo" and "name=foo".
+ *
+ * We expect that named hierarchies do not conflict in name with a
+ * kernel hierarchy, modulo the "name=" prefix.
+ *
+ * We always generate "normalized" controller names, i.e. without the
+ * "name=" prefix.
+ *
+ * We require absolute cgroup paths. When returning, we will always
+ * generate paths with multiple adjacent / removed.
+ */
+
 int cg_enumerate_processes(const char *controller, const char *path, FILE **_f);
-int cg_enumerate_tasks(const char *controller, const char *path, FILE **_f);
 int cg_read_pid(FILE *f, pid_t *_pid);
 
-int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d);
-int cg_read_subgroup(DIR *d, char **fn);
-
 int cg_kill(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, Set *s);
-int cg_kill_recursive(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, bool remove, Set *s);
-int cg_kill_recursive_and_wait(const char *controller, const char *path, bool remove);
-
-int cg_migrate(const char *controller, const char *from, const char *to, bool ignore_self);
-int cg_migrate_recursive(const char *controller, const char *from, const char *to, bool ignore_self, bool remove);
-
-int cg_split_spec(const char *spec, char **controller, char **path);
-int cg_join_spec(const char *controller, const char *path, char **spec);
-int cg_fix_path(const char *path, char **result);
 
 int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs);
-int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs);
-int cg_get_by_pid(const char *controller, pid_t pid, char **path);
-
-int cg_trim(const char *controller, const char *path, bool delete_root);
-
-int cg_rmdir(const char *controller, const char *path, bool honour_sticky);
-int cg_delete(const char *controller, const char *path);
-
-int cg_create(const char *controller, const char *path);
-int cg_attach(const char *controller, const char *path, pid_t pid);
-int cg_create_and_attach(const char *controller, const char *path, pid_t pid);
-
-int cg_set_group_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid);
-int cg_set_task_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid, int sticky);
-
-int cg_install_release_agent(const char *controller, const char *agent);
-
-int cg_is_empty(const char *controller, const char *path, bool ignore_self);
-int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self);
-
-int cg_get_user_path(char **path);
-int cg_pid_get_cgroup(pid_t pid, char **root, char **cgroup);
-int cg_pid_get_unit(pid_t pid, char **unit);
 
-char **cg_shorten_controllers(char **controllers);
+bool cg_controller_is_valid(const char *p, bool allow_named);
diff --git a/src/libudev/path-util.h b/src/libudev/path-util.h
index 348157fc10..78413c9aa2 100644
--- a/src/libudev/path-util.h
+++ b/src/libudev/path-util.h
@@ -36,6 +36,7 @@ bool path_equal(const char *a, const char *b) _pure_;
 
 char** path_strv_make_absolute_cwd(char **l);
 char** path_strv_canonicalize(char **l);
+char** path_strv_canonicalize_uniq(char **l);
 
 int path_is_mount_point(const char *path, bool allow_symlink);
 int path_is_read_only_fs(const char *path);
diff --git a/src/libudev/set.h b/src/libudev/set.h
index 9162e2ae80..8864f7b34e 100644
--- a/src/libudev/set.h
+++ b/src/libudev/set.h
@@ -33,7 +33,15 @@ typedef struct Set Set;
 
 Set *set_new(hash_func_t hash_func, compare_func_t compare_func);
 void set_free(Set* s);
+static inline void set_freep(Set **s) {
+        set_free(*s);
+}
+
 void set_free_free(Set *s);
+static inline void set_free_freep(Set **s) {
+        set_free_free(*s);
+}
+
 Set* set_copy(Set *s);
 int set_ensure_allocated(Set **s, hash_func_t hash_func, compare_func_t compare_func);
 
@@ -69,3 +77,6 @@ char **set_get_strv(Set *s);
 
 #define SET_FOREACH_BACKWARDS(e, s, i) \
         for ((i) = ITERATOR_LAST, (e) = set_iterate_backwards((s), &(i)); (e); (e) = set_iterate_backwards((s), &(i)))
+
+#define _cleanup_set_free_ _cleanup_(set_freep)
+#define _cleanup_set_free_free_ _cleanup_(set_free_freep)