X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fcgroup-util.c;h=74889b636324dea71c0426e05740198a5f21286b;hp=e54b94658c0e73a0d9c447f70d71b0be6c48c839;hb=d4fffc4b8beb86e77fd710c1f43913a490ed083a;hpb=aff38e74bd776471f15ba54b305a24b0251eb865

diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index e54b94658..74889b636 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -38,6 +38,8 @@
 #include "strv.h"
 #include "unit-name.h"
 #include "fileio.h"
+#include "special.h"
+#include "mkdir.h"
 
 int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
         _cleanup_free_ char *fs = NULL;
@@ -58,25 +60,6 @@ int cg_enumerate_processes(const char *controller, const char *path, FILE **_f)
         return 0;
 }
 
-int cg_enumerate_tasks(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, "tasks", &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;
 
@@ -150,7 +133,7 @@ int cg_read_subgroup(DIR *d, char **fn) {
         return 0;
 }
 
-int cg_rmdir(const char *controller, const char *path, bool honour_sticky) {
+int cg_rmdir(const char *controller, const char *path) {
         _cleanup_free_ char *p = NULL;
         int r;
 
@@ -158,22 +141,6 @@ int cg_rmdir(const char *controller, const char *path, bool honour_sticky) {
         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)
-                        return -ENOMEM;
-
-                r = file_is_priv_sticky(tasks);
-                free(tasks);
-
-                if (r > 0)
-                        return 0;
-        }
-
         r = rmdir(p);
         if (r < 0 && errno != ENOENT)
                 return -errno;
@@ -304,7 +271,7 @@ int cg_kill_recursive(const char *controller, const char *path, int sig, bool si
                 ret = r;
 
         if (rem) {
-                r = cg_rmdir(controller, path, true);
+                r = cg_rmdir(controller, path);
                 if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
                         return r;
         }
@@ -312,37 +279,6 @@ int cg_kill_recursive(const char *controller, const char *path, int sig, bool si
         return ret;
 }
 
-int cg_kill_recursive_and_wait(const char *controller, const char *path, bool rem) {
-        unsigned i;
-
-        assert(path);
-
-        /* 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;
-
-                r = cg_kill_recursive(controller, path, sig, true, true, rem, NULL);
-                if (r <= 0)
-                        return r;
-
-                usleep(200 * USEC_PER_MSEC);
-        }
-
-        return 0;
-}
-
 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;
@@ -365,7 +301,7 @@ int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char
                 pid_t pid = 0;
                 done = true;
 
-                r = cg_enumerate_tasks(cfrom, pfrom, &f);
+                r = cg_enumerate_processes(cfrom, pfrom, &f);
                 if (r < 0) {
                         if (ret >= 0 && r != -ENOENT)
                                 return r;
@@ -413,7 +349,14 @@ int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char
         return ret;
 }
 
-int cg_migrate_recursive(const char *cfrom, const char *pfrom, const char *cto, const char *pto, bool ignore_self, bool rem) {
+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;
@@ -454,7 +397,7 @@ int cg_migrate_recursive(const char *cfrom, const char *pfrom, const char *cto,
                 ret = r;
 
         if (rem) {
-                r = cg_rmdir(cfrom, pfrom, true);
+                r = cg_rmdir(cfrom, pfrom);
                 if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
                         return r;
         }
@@ -462,6 +405,37 @@ int cg_migrate_recursive(const char *cfrom, const char *pfrom, const char *cto,
         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) {
+                        r = cg_migrate_recursive(cfrom, pfrom, cto, prefix, ignore_self, rem);
+                        if (r >= 0)
+                                break;
+                }
+        }
+
+        return 0;
+}
+
 static const char *normalize_controller(const char *controller) {
 
         assert(controller);
@@ -477,19 +451,19 @@ 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) {
-                if (path && suffix)
+        if (!isempty(controller)) {
+                if (!isempty(path) && !isempty(suffix))
                         t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
-                else if (path)
+                else if (!isempty(path))
                         t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL);
-                else if (suffix)
+                else if (!isempty(suffix))
                         t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL);
                 else
                         t = strappend("/sys/fs/cgroup/", controller);
         } else {
-                if (path && suffix)
+                if (!isempty(path) && !isempty(suffix))
                         t = strjoin(path, "/", suffix, NULL);
-                else if (path)
+                else if (!isempty(path))
                         t = strdup(path);
                 else
                         return -EINVAL;
@@ -506,10 +480,13 @@ static int join_path(const char *controller, const char *path, const char *suffi
 
 int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
         const char *p;
-        static __thread bool good = false;
+        static thread_local bool good = false;
 
         assert(fs);
 
+        if (controller && !cg_controller_is_valid(controller, true))
+                return -EINVAL;
+
         if (_unlikely_(!good)) {
                 int r;
 
@@ -546,7 +523,7 @@ int cg_get_path_and_check(const char *controller, const char *path, const char *
 
         assert(fs);
 
-        if (isempty(controller))
+        if (!cg_controller_is_valid(controller, true))
                 return -EINVAL;
 
         /* Normalize the controller syntax */
@@ -561,8 +538,9 @@ int cg_get_path_and_check(const char *controller, const char *path, const char *
 }
 
 static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
-        char *p;
-        bool is_sticky;
+        assert(path);
+        assert(sb);
+        assert(ftwbuf);
 
         if (typeflag != FTW_DP)
                 return 0;
@@ -570,18 +548,6 @@ static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct
         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;
 }
@@ -601,19 +567,8 @@ int cg_trim(const char *controller, const char *path, bool delete_root) {
                 r = errno ? -errno : -EIO;
 
         if (delete_root) {
-                bool is_sticky;
-                char *p;
-
-                p = strappend(fs, "/tasks");
-                if (!p)
-                        return -ENOMEM;
-
-                is_sticky = file_is_priv_sticky(p) > 0;
-                free(p);
-
-                if (!is_sticky)
-                        if (rmdir(fs) < 0 && errno != ENOENT && r == 0)
-                                return -errno;
+                if (rmdir(fs) < 0 && errno != ENOENT)
+                        return -errno;
         }
 
         return r;
@@ -633,6 +588,46 @@ int cg_delete(const char *controller, const char *path) {
         return r == -ENOENT ? 0 : 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];
@@ -641,7 +636,7 @@ int cg_attach(const char *controller, const char *path, pid_t pid) {
         assert(path);
         assert(pid >= 0);
 
-        r = cg_get_path_and_check(controller, path, "tasks", &fs);
+        r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs);
         if (r < 0)
                 return r;
 
@@ -653,6 +648,30 @@ int cg_attach(const char *controller, const char *path, pid_t pid) {
         return write_string_file(fs, c);
 }
 
+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) {
+                        r = cg_attach(controller, prefix, pid);
+                        if (r >= 0)
+                                break;
+                }
+        }
+
+        return 0;
+}
+
 int cg_set_group_access(
                 const char *controller,
                 const char *path,
@@ -680,52 +699,30 @@ int cg_set_task_access(
                 const char *path,
                 mode_t mode,
                 uid_t uid,
-                gid_t gid,
-                int sticky) {
+                gid_t gid) {
 
         _cleanup_free_ char *fs = NULL, *procs = NULL;
         int r;
 
         assert(path);
 
-        if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1 && sticky < 0)
+        if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1)
                 return 0;
 
         if (mode != (mode_t) -1)
                 mode &= 0666;
 
-        r = cg_get_path(controller, path, "tasks", &fs);
+        r = cg_get_path(controller, path, "cgroup.procs", &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)
-                        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);
         if (r < 0)
                 return r;
 
-        /* Always keep values for "cgroup.procs" in sync with "tasks" */
-        r = cg_get_path(controller, path, "cgroup.procs", &procs);
+        /* Compatibility, Always keep values for "tasks" in sync with
+         * "cgroup.procs" */
+        r = cg_get_path(controller, path, "tasks", &procs);
         if (r < 0)
                 return r;
 
@@ -733,21 +730,27 @@ int cg_set_task_access(
 }
 
 int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
-        char fs[sizeof("/proc/") - 1 + DECIMAL_STR_MAX(pid_t) + sizeof("/cgroup")];
         _cleanup_fclose_ FILE *f = NULL;
         char line[LINE_MAX];
+        const char *fs;
         size_t cs;
 
         assert(path);
         assert(pid >= 0);
 
-        if (!controller)
+        if (controller) {
+                if (!cg_controller_is_valid(controller, true))
+                        return -EINVAL;
+
+                controller = normalize_controller(controller);
+        } else
                 controller = SYSTEMD_CGROUP_CONTROLLER;
 
         if (pid == 0)
-                pid = getpid();
+                fs = "/proc/self/cgroup";
+        else
+                fs = procfs_file_alloca(pid, "cgroup");
 
-        sprintf(fs, "/proc/%lu/cgroup", (unsigned long) pid);
         f = fopen(fs, "re");
         if (!f)
                 return errno == ENOENT ? -ESRCH : -errno;
@@ -755,7 +758,10 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
         cs = strlen(controller);
 
         FOREACH_LINE(line, f, return -errno) {
-                char *l, *p;
+                char *l, *p, *w, *e;
+                size_t k;
+                char *state;
+                bool found = false;
 
                 truncate_nl(line);
 
@@ -764,13 +770,31 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
                         continue;
 
                 l++;
-                if (!strneq(l, controller, cs))
+                e = strchr(l, ':');
+                if (!e)
                         continue;
 
-                if (l[cs] != ':')
+                *e = 0;
+
+                FOREACH_WORD_SEPARATOR(w, k, l, ",", state) {
+
+                        if (k == cs && memcmp(w, controller, cs) == 0) {
+                                found = true;
+                                break;
+                        }
+
+                        if (k == 5 + cs &&
+                            memcmp(w, "name=", 5) == 0 &&
+                            memcmp(w+5, controller, cs) == 0) {
+                                found = true;
+                                break;
+                        }
+                }
+
+                if (!found)
                         continue;
 
-                p = strdup(l + cs + 1);
+                p = strdup(e + 1);
                 if (!p)
                         return -ENOMEM;
 
@@ -831,6 +855,32 @@ int cg_install_release_agent(const char *controller, const char *agent) {
         return 0;
 }
 
+int cg_uninstall_release_agent(const char *controller) {
+        _cleanup_free_ char *fs = NULL;
+        int r;
+
+        r = cg_get_path(controller, NULL, "notify_on_release", &fs);
+        if (r < 0)
+                return r;
+
+        r = write_string_file(fs, "0");
+        if (r < 0)
+                return r;
+
+        free(fs);
+        fs = NULL;
+
+        r = cg_get_path(controller, NULL, "release_agent", &fs);
+        if (r < 0)
+                return r;
+
+        r = write_string_file(fs, "");
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
 int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
         _cleanup_fclose_ FILE *f = NULL;
         pid_t pid = 0, self_pid;
@@ -839,7 +889,7 @@ int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
 
         assert(path);
 
-        r = cg_enumerate_tasks(controller, path, &f);
+        r = cg_enumerate_processes(controller, path, &f);
         if (r < 0)
                 return r == -ENOENT ? 1 : r;
 
@@ -860,19 +910,6 @@ int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
         return !found;
 }
 
-int cg_is_empty_by_spec(const char *spec, bool ignore_self) {
-        _cleanup_free_ char *controller = NULL, *path = NULL;
-        int r;
-
-        assert(spec);
-
-        r = cg_split_spec(spec, &controller, &path);
-        if (r < 0)
-                return r;
-
-        return cg_is_empty(controller, path, ignore_self);
-}
-
 int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
         _cleanup_closedir_ DIR *d = NULL;
         char *fn;
@@ -910,6 +947,7 @@ int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_
 int cg_split_spec(const char *spec, char **controller, char **path) {
         const char *e;
         char *t = NULL, *u = NULL;
+        _cleanup_free_ char *v = NULL;
 
         assert(spec);
 
@@ -922,6 +960,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                         if (!t)
                                 return -ENOMEM;
 
+                        path_kill_slashes(t);
                         *path = t;
                 }
 
@@ -933,11 +972,11 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
 
         e = strchr(spec, ':');
         if (!e) {
-                if (!filename_is_safe(spec))
+                if (!cg_controller_is_valid(spec, true))
                         return -EINVAL;
 
                 if (controller) {
-                        t = strdup(spec);
+                        t = strdup(normalize_controller(spec));
                         if (!t)
                                 return -ENOMEM;
 
@@ -950,23 +989,38 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                 return 0;
         }
 
-        t = strndup(spec, e-spec);
+        v = strndup(spec, e-spec);
+        if (!v)
+                return -ENOMEM;
+        t = strdup(normalize_controller(v));
         if (!t)
                 return -ENOMEM;
-        if (!filename_is_safe(t)) {
+        if (!cg_controller_is_valid(t, true)) {
                 free(t);
                 return -EINVAL;
         }
 
-        u = strdup(e+1);
-        if (!u) {
-                free(t);
-                return -ENOMEM;
-        }
-        if (!path_is_safe(u)) {
-                free(t);
-                free(u);
-                return -EINVAL;
+        if (streq(e+1, "")) {
+                u = strdup("/");
+                if (!u) {
+                        free(t);
+                        return -ENOMEM;
+                }
+        } 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)
@@ -982,33 +1036,9 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
         return 0;
 }
 
-int cg_join_spec(const char *controller, const char *path, char **spec) {
-        char *s;
-
-        assert(path);
-
-        if (!controller)
-                controller = "systemd";
-        else if (controller[0] == 0 ||
-                 strchr(controller, ':') ||
-                 strchr(controller, '/'))
-                return -EINVAL;
-
-        if (!path_is_absolute(path))
-                return -EINVAL;
-
-        controller = normalize_controller(controller);
-
-        s = strjoin(controller, ":", path, NULL);
-        if (!s)
-                return -ENOMEM;
-
-        *spec = s;
-        return 0;
-}
-
 int cg_mangle_path(const char *path, char **result) {
-        char *t, *c, *p;
+        _cleanup_free_ char *c = NULL, *p = NULL;
+        char *t;
         int r;
 
         assert(path);
@@ -1021,6 +1051,7 @@ int cg_mangle_path(const char *path, char **result) {
                 if (!t)
                         return -ENOMEM;
 
+                path_kill_slashes(t);
                 *result = t;
                 return 0;
         }
@@ -1030,210 +1061,102 @@ int cg_mangle_path(const char *path, char **result) {
         if (r < 0)
                 return r;
 
-        r = cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
-        free(c);
-        free(p);
-
-        return r;
+        return cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
 }
 
-int cg_get_system_path(char **path) {
-        char *p;
+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) {
-                p = strdup("/system");
-                if (!p)
-                        return -ENOMEM;
-        }
-
-        if (endswith(p, "/system"))
-                *path = p;
-        else {
-                char *q;
-
-                q = strappend(p, "/system");
-                free(p);
-                if (!q)
-                        return -ENOMEM;
+        if (r < 0)
+                return r;
 
-                *path = q;
-        }
+        e = endswith(p, "/" SPECIAL_SYSTEM_SLICE);
+        if (e)
+                *e = 0;
 
+        *path = p;
         return 0;
 }
 
-int cg_get_root_path(char **path) {
-        char *root, *e;
+int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
+        _cleanup_free_ char *cg_root = NULL;
+        char *cg_process, *p;
         int r;
 
-        assert(path);
+        assert(pid >= 0);
+        assert(cgroup);
+
+        if (!root) {
+                /* If the root was specified let's use that, otherwise
+                 * let's determine it from PID 1 */
+
+                r = cg_get_root_path(&cg_root);
+                if (r < 0)
+                        return r;
 
-        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &root);
+                root = cg_root;
+        }
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
         if (r < 0)
                 return r;
 
-        e = endswith(root, "/system");
-        if (e == root)
-                e[1] = 0;
-        else if (e)
-                *e = 0;
+        p = path_startswith(cg_process, root);
+        if (p) {
+                char *c;
+
+                c = strdup(p - 1);
+                free(cg_process);
+
+                if (!c)
+                        return -ENOMEM;
+
+                *cgroup = c;
+        } else
+                *cgroup = cg_process;
 
-        *path = root;
         return 0;
 }
 
-int cg_get_user_path(char **path) {
-        _cleanup_free_ char *root = NULL;
-        char *p;
+int cg_path_decode_unit(const char *cgroup, char **unit){
+        char *e, *c, *s;
 
-        assert(path);
+        assert(cgroup);
+        assert(unit);
 
-        /* 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" */
+        e = strchrnul(cgroup, '/');
+        c = strndupa(cgroup, e - cgroup);
+        c = cg_unescape(c);
 
-        if (cg_get_root_path(&root) < 0 || streq(root, "/"))
-                p = strdup("/user");
-        else
-                p = strappend(root, "/user");
+        if (!unit_name_is_valid(c, false))
+                return -EINVAL;
 
-        if (!p)
+        s = strdup(c);
+        if (!s)
                 return -ENOMEM;
 
-        *path = p;
+        *unit = s;
         return 0;
 }
 
-int cg_get_machine_path(char **path) {
-        _cleanup_free_ char *root = NULL;
-        char *p;
+static const char *skip_slices(const char *p) {
+        /* Skips over all slice assignments */
 
-        assert(path);
+        for (;;) {
+                size_t n;
 
-        if (cg_get_root_path(&root) < 0 || streq(root, "/"))
-                p = strdup("/machine");
-        else
-                p = strappend(root, "/machine");
-
-        if (!p)
-                return -ENOMEM;
-
-        *path = p;
-        return 0;
-}
-
-char **cg_shorten_controllers(char **controllers) {
-        char **f, **t;
-
-        if (!controllers)
-                return controllers;
-
-        for (f = controllers, t = controllers; *f; f++) {
-                const char *p;
-                int r;
-
-                p = normalize_controller(*f);
-
-                if (streq(*f, "systemd")) {
-                        free(*f);
-                        continue;
-                }
-
-                r = check_hierarchy(p);
-                if (r < 0) {
-                        log_debug("Controller %s is not available, removing from controllers list.", *f);
-                        free(*f);
-                        continue;
-                }
-
-                *(t++) = *f;
-        }
-
-        *t = NULL;
-        return strv_uniq(controllers);
-}
-
-int cg_pid_get_path_shifted(pid_t pid, char **root, char **cgroup) {
-        _cleanup_free_ char *cg_root = NULL;
-        char *cg_process, *p;
-        int r;
-
-        r = cg_get_root_path(&cg_root);
-        if (r < 0)
-                return r;
-
-        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
-        if (r < 0)
-                return r;
-
-        p = path_startswith(cg_process, cg_root);
-        if (p)
-                p--;
-        else
-                p = cg_process;
+                p += strspn(p, "/");
 
-        if (cgroup) {
-                char* c;
+                n = strcspn(p, "/");
+                if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0)
+                        return p;
 
-                c = strdup(p);
-                if (!c) {
-                        free(cg_process);
-                        return -ENOMEM;
-                }
-
-                *cgroup = c;
+                p += n;
         }
-
-        if (root) {
-                cg_process[p-cg_process] = 0;
-                *root = cg_process;
-        } else
-                free(cg_process);
-
-        return 0;
-}
-
-/* non-static only for testing purposes */
-int cg_path_decode_unit(const char *cgroup, char **unit){
-        char *p, *e, *c, *s, *k;
-
-        assert(cgroup);
-        assert(unit);
-
-        e = strchrnul(cgroup, '/');
-        c = strndupa(cgroup, e - cgroup);
-
-        /* Could this be a valid unit name? */
-        if (!unit_name_is_valid(c, true))
-                return -EINVAL;
-
-        if (!unit_name_is_template(c))
-                s = strdup(c);
-        else {
-                if (*e != '/')
-                        return -EINVAL;
-
-                e += strspn(e, "/");
-                p = strchrnul(e, '/');
-
-                /* Don't allow empty instance strings */
-                if (p == e)
-                        return -EINVAL;
-
-                k = strndupa(e, p - e);
-
-                s = unit_name_replace_instance(c, k);
-        }
-
-        if (!s)
-                return -ENOMEM;
-
-        *unit = s;
-        return 0;
 }
 
 int cg_path_get_unit(const char *path, char **unit) {
@@ -1242,9 +1165,7 @@ int cg_path_get_unit(const char *path, char **unit) {
         assert(path);
         assert(unit);
 
-        e = path_startswith(path, "/system/");
-        if (!e)
-                return -ENOENT;
+        e = skip_slices(path);
 
         return cg_path_decode_unit(e, unit);
 }
@@ -1262,19 +1183,48 @@ int cg_pid_get_unit(pid_t pid, char **unit) {
         return cg_path_get_unit(cgroup, unit);
 }
 
-static const char *skip_label(const char *e) {
-        assert(e);
+/**
+ * Skip session-*.scope, but require it to be there.
+ */
+static const char *skip_session(const char *p) {
+        size_t n;
 
-        e = strchr(e, '/');
-        if (!e)
+        assert(p);
+
+        p += strspn(p, "/");
+
+        n = strcspn(p, "/");
+        if (n < strlen("session-x.scope") || memcmp(p, "session-", 8) != 0 || memcmp(p + n - 6, ".scope", 6) != 0)
                 return NULL;
 
-        e += strspn(e, "/");
-        return e;
+        p += n;
+        p += strspn(p, "/");
+
+        return p;
+}
+
+/**
+ * Skip user@*.service, but require it to be there.
+ */
+static const char *skip_user_manager(const char *p) {
+        size_t n;
+
+        assert(p);
+
+        p += strspn(p, "/");
+
+        n = strcspn(p, "/");
+        if (n < strlen("user@x.service") || memcmp(p, "user@", 5) != 0 || memcmp(p + n - 8, ".service", 8) != 0)
+                return NULL;
+
+        p += n;
+        p += strspn(p, "/");
+
+        return p;
 }
 
 int cg_path_get_user_unit(const char *path, char **unit) {
-        const char *e;
+        const char *e, *t;
 
         assert(path);
         assert(unit);
@@ -1283,24 +1233,20 @@ int cg_path_get_user_unit(const char *path, char **unit) {
          * cgroups might have arbitrary child cgroups and we shouldn't get
          * confused by those */
 
-        e = path_startswith(path, "/user/");
-        if (!e)
-                return -ENOENT;
+        /* Skip slices, if there are any */
+        e = skip_slices(path);
 
-        /* Skip the user name */
-        e = skip_label(e);
-        if (!e)
-                return -ENOENT;
-
-        /* Skip the session ID */
-        e = skip_label(e);
-        if (!e)
-                return -ENOENT;
-
-        /* Skip the systemd cgroup */
-        e = skip_label(e);
-        if (!e)
-                return -ENOENT;
+        /* Skip the session scope... */
+        t = skip_session(e);
+        if (t)
+                /* ... and skip more slices if there's one */
+                e = skip_slices(t);
+        else {
+                /* ... or require a user manager unit to be there */
+                e = skip_user_manager(e);
+                if (!e)
+                        return -ENOENT;
+        }
 
         return cg_path_decode_unit(e, unit);
 }
@@ -1319,29 +1265,38 @@ int cg_pid_get_user_unit(pid_t pid, char **unit) {
 }
 
 int cg_path_get_machine_name(const char *path, char **machine) {
-        const char *e, *n;
-        char *s, *dot;
+        const char *e, *n, *x;
+        char *s, *r;
+        size_t l;
 
         assert(path);
         assert(machine);
 
-        e = path_startswith(path, "/machine/");
-        if (!e)
-                return -ENOENT;
+        /* Skip slices, if there are any */
+        e = skip_slices(path);
 
         n = strchrnul(e, '/');
         if (e == n)
                 return -ENOENT;
 
-        s = strndup(e, n - e);
-        if (!s)
-                return -ENOMEM;
+        s = strndupa(e, n - e);
+        s = cg_unescape(s);
 
-        dot = strrchr(s, '.');
-        if (dot)
-                *dot = 0;
+        x = startswith(s, "machine-");
+        if (!x)
+                return -ENOENT;
+        if (!endswith(x, ".scope"))
+                return -ENOENT;
+
+        l = strlen(x);
+        if (l <= 6)
+                return -ENOENT;
+
+        r = strndup(x, l - 6);
+        if (!r)
+                return -ENOMEM;
 
-        *machine = s;
+        *machine = r;
         return 0;
 }
 
@@ -1359,33 +1314,38 @@ int cg_pid_get_machine_name(pid_t pid, char **machine) {
 }
 
 int cg_path_get_session(const char *path, char **session) {
-        const char *e, *n;
-        char *s;
+        const char *e, *n, *x;
+        char *s, *r;
+        size_t l;
 
         assert(path);
         assert(session);
 
-        e = path_startswith(path, "/user/");
-        if (!e)
-                return -ENOENT;
-
-        /* Skip the user name */
-        e = skip_label(e);
-        if (!e)
-                return -ENOENT;
+        /* Skip slices, if there are any */
+        e = skip_slices(path);
 
         n = strchrnul(e, '/');
         if (e == n)
                 return -ENOENT;
 
-        if (n - e == 6 && memcmp(e, "shared", 6) == 0)
+        s = strndupa(e, n - e);
+        s = cg_unescape(s);
+
+        x = startswith(s, "session-");
+        if (!x)
+                return -ENOENT;
+        if (!endswith(x, ".scope"))
                 return -ENOENT;
 
-        s = strndup(e, n - e);
-        if (!s)
+        l = strlen(x);
+        if (l <= 6)
+                return -ENOENT;
+
+        r = strndup(x, l - 6);
+        if (!r)
                 return -ENOMEM;
 
-        *session = s;
+        *session = r;
         return 0;
 }
 
@@ -1402,31 +1362,364 @@ int cg_pid_get_session(pid_t pid, char **session) {
         return cg_path_get_session(cgroup, session);
 }
 
-int cg_controller_from_attr(const char *attr, char **controller) {
-        const char *dot;
-        char *c;
+int cg_path_get_owner_uid(const char *path, uid_t *uid) {
+        _cleanup_free_ char *slice = NULL;
+        const char *start, *end;
+        char *s;
+        uid_t u;
+        int r;
 
-        assert(attr);
-        assert(controller);
+        assert(path);
+
+        r = cg_path_get_slice(path, &slice);
+        if (r < 0)
+                return r;
+
+        start = startswith(slice, "user-");
+        if (!start)
+                return -ENOENT;
+        end = endswith(slice, ".slice");
+        if (!end)
+                return -ENOENT;
+
+        s = strndupa(start, end - start);
+        if (!s)
+                return -ENOENT;
+
+        if (parse_uid(s, &u) < 0)
+                return -EIO;
+
+        if (uid)
+                *uid = u;
+
+        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;
 
-        if (!filename_is_safe(attr))
+        return cg_path_get_owner_uid(cgroup, uid);
+}
+
+int cg_path_get_slice(const char *p, char **slice) {
+        const char *e = NULL;
+        size_t m = 0;
+
+        assert(p);
+        assert(slice);
+
+        for (;;) {
+                size_t n;
+
+                p += strspn(p, "/");
+
+                n = strcspn(p, "/");
+                if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0) {
+                        char *s;
+
+                        if (!e)
+                                return -ENOENT;
+
+                        s = strndup(e, m);
+                        if (!s)
+                                return -ENOMEM;
+
+                        *slice = s;
+                        return 0;
+                }
+
+                e = p;
+                m = n;
+
+                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);
+}
+
+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"))
+                need_prefix = true;
+        else {
+                const char *dot;
+
+                dot = strrchr(p, '.');
+                if (dot) {
+
+                        if (dot - p == 6 && memcmp(p, "cgroup", 6) == 0)
+                                need_prefix = true;
+                        else {
+                                char *n;
+
+                                n = strndupa(p, dot - p);
+
+                                if (check_hierarchy(n) >= 0)
+                                        need_prefix = true;
+                        }
+                }
+        }
+
+        if (need_prefix)
+                return strappend("_", p);
+        else
+                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, bool allow_named) {
+        const char *t, *s;
+
+        if (!p)
+                return false;
+
+        if (allow_named) {
+                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;
+
+        assert(unit);
+        assert(ret);
+
+        if (!unit_name_is_valid(unit, false))
                 return -EINVAL;
 
-        dot = strchr(attr, '.');
-        if (!dot) {
-                *controller = NULL;
-                return 0;
+        if (!endswith(unit, ".slice"))
+                return -EINVAL;
+
+        p = unit_name_to_prefix(unit);
+        if (!p)
+                return -ENOMEM;
+
+        dash = strchr(p, '-');
+        while (dash) {
+                _cleanup_free_ char *escaped = NULL;
+                char n[dash - p + sizeof(".slice")];
+
+                strcpy(stpncpy(n, p, dash - p), ".slice");
+
+                if (!unit_name_is_valid(n, false))
+                        return -EINVAL;
+
+                escaped = cg_escape(n);
+                if (!escaped)
+                        return -ENOMEM;
+
+                if (!strextend(&s, escaped, "/", NULL))
+                        return -ENOMEM;
+
+                dash = strchr(dash+1, '-');
         }
 
-        c = strndup(attr, dot - attr);
-        if (!c)
+        e = cg_escape(unit);
+        if (!e)
                 return -ENOMEM;
 
-        if (!filename_is_safe(c)) {
-                free(c);
-                return -EINVAL;
+        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);
+}
+
+static const char mask_names[] =
+        "cpu\0"
+        "cpuacct\0"
+        "blkio\0"
+        "memory\0"
+        "devices\0";
+
+int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path) {
+        CGroupControllerMask bit = 1;
+        const char *n;
+        int r;
+
+        /* 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;
+
+        /* Then, do the same in the other hierarchies */
+        NULSTR_FOREACH(n, mask_names) {
+                if (mask & bit)
+                        cg_create(n, path);
+                else if (supported & bit)
+                        cg_trim(n, path, true);
+
+                bit <<= 1;
         }
 
-        *controller = c;
-        return 1;
+        return 0;
+}
+
+int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid) {
+        CGroupControllerMask bit = 1;
+        const char *n;
+        int r;
+
+        r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
+        if (r < 0)
+                return r;
+
+        NULSTR_FOREACH(n, mask_names) {
+                if (supported & bit)
+                        cg_attach_fallback(n, path, pid);
+
+                bit <<= 1;
+        }
+
+        return 0;
+}
+
+int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids) {
+        Iterator i;
+        void *pidp;
+        int r = 0;
+
+        SET_FOREACH(pidp, pids, i) {
+                pid_t pid = PTR_TO_LONG(pidp);
+                int q;
+
+                q = cg_attach_everywhere(supported, path, pid);
+                if (q < 0)
+                        r = q;
+        }
+
+        return r;
+}
+
+int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to) {
+        CGroupControllerMask bit = 1;
+        const char *n;
+        int r;
+
+        if (!path_equal(from, to))  {
+                r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true);
+                if (r < 0)
+                        return r;
+        }
+
+        NULSTR_FOREACH(n, mask_names) {
+                if (supported & bit)
+                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, to, false, false);
+
+                bit <<= 1;
+        }
+
+        return 0;
+}
+
+int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root) {
+        CGroupControllerMask bit = 1;
+        const char *n;
+        int r;
+
+        r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
+        if (r < 0)
+                return r;
+
+        NULSTR_FOREACH(n, mask_names) {
+                if (supported & bit)
+                        cg_trim(n, path, delete_root);
+
+                bit <<= 1;
+        }
+
+        return 0;
+}
+
+CGroupControllerMask cg_mask_supported(void) {
+        CGroupControllerMask bit = 1, mask = 0;
+        const char *n;
+
+        NULSTR_FOREACH(n, mask_names) {
+                if (check_hierarchy(n) >= 0)
+                        mask |= bit;
+
+                bit <<= 1;
+        }
+
+        return mask;
 }