chiark / gitweb /
core: find the closest parent slice that has a specfic cgroup controller enabled...
[elogind.git] / src / shared / cgroup-util.c
index 5816b7d4d6fd991a3c4d9cb8ce17ba978a8ab502..1aa81c2cd18f1700a75631a4d6b9b1659dba3e9b 100644 (file)
@@ -39,6 +39,7 @@
 #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;
@@ -193,12 +194,12 @@ int cg_kill(const char *controller, const char *path, int sig, bool sigcont, boo
                         if (kill(pid, sig) < 0) {
                                 if (ret >= 0 && errno != ESRCH)
                                         ret = -errno;
-                        } else if (ret == 0) {
-
+                        } else {
                                 if (sigcont)
                                         kill(pid, SIGCONT);
 
-                                ret = 1;
+                                if (ret == 0)
+                                        ret = 1;
                         }
 
                         done = false;
@@ -278,37 +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;
@@ -435,6 +405,37 @@ int cg_migrate_recursive(
         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);
@@ -479,7 +480,7 @@ 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);
 
@@ -587,6 +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];
@@ -607,6 +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,
@@ -681,10 +746,7 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
         } else
                 controller = SYSTEMD_CGROUP_CONTROLLER;
 
-        if (pid == 0)
-                fs = "/proc/self/cgroup";
-        else
-                fs = procfs_file_alloca(pid, "cgroup");
+        fs = procfs_file_alloca(pid, "cgroup");
 
         f = fopen(fs, "re");
         if (!f)
@@ -790,6 +852,32 @@ 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;
@@ -819,19 +907,6 @@ 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;
@@ -922,19 +997,28 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                 return -EINVAL;
         }
 
-        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;
-        }
+        if (streq(e+1, "")) {
+                u = strdup("/");
+                if (!u) {
+                        free(t);
+                        return -ENOMEM;
+                }
+        } else {
+                u = strdup(e+1);
+                if (!u) {
+                        free(t);
+                        return -ENOMEM;
+                }
 
-        path_kill_slashes(u);
+                if (!path_is_safe(u) ||
+                    !path_is_absolute(u)) {
+                        free(t);
+                        free(u);
+                        return -EINVAL;
+                }
+
+                path_kill_slashes(u);
+        }
 
         if (controller)
                 *controller = t;
@@ -949,33 +1033,6 @@ 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 (!cg_controller_is_valid(controller, true))
-                        return -EINVAL;
-
-                controller = normalize_controller(controller);
-        }
-
-        if (!path_is_absolute(path))
-                return -EINVAL;
-
-        s = strjoin(controller, ":", path, NULL);
-        if (!s)
-                return -ENOMEM;
-
-        path_kill_slashes(s + strlen(controller) + 1);
-
-        *spec = s;
-        return 0;
-}
-
 int cg_mangle_path(const char *path, char **result) {
         _cleanup_free_ char *c = NULL, *p = NULL;
         char *t;
@@ -1022,85 +1079,68 @@ int cg_get_root_path(char **path) {
         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);
+int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
+        _cleanup_free_ char *rt = NULL;
+        char *p;
+        int r;
 
-                if (streq(p, "systemd")) {
-                        free(*f);
-                        continue;
-                }
+        assert(cgroup);
+        assert(shifted);
 
-                if (!cg_controller_is_valid(p, true)) {
-                        log_warning("Controller %s is not valid, removing from controllers list.", p);
-                        free(*f);
-                        continue;
-                }
+        if (!root) {
+                /* If the root was specified let's use that, otherwise
+                 * let's determine it from PID 1 */
 
-                r = check_hierarchy(p);
-                if (r < 0) {
-                        log_debug("Controller %s is not available, removing from controllers list.", p);
-                        free(*f);
-                        continue;
-                }
+                r = cg_get_root_path(&rt);
+                if (r < 0)
+                        return r;
 
-                *(t++) = *f;
+                root = rt;
         }
 
-        *t = NULL;
-        return strv_uniq(controllers);
+        p = path_startswith(cgroup, root);
+        if (p)
+                *shifted = p - 1;
+        else
+                *shifted = cgroup;
+
+        return 0;
 }
 
-int cg_pid_get_path_shifted(pid_t pid, char **root, char **cgroup) {
-        _cleanup_free_ char *cg_root = NULL;
-        char *cg_process, *p;
+int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
+        _cleanup_free_ char *raw = NULL;
+        const char *c;
         int r;
 
-        r = cg_get_root_path(&cg_root);
+        assert(pid >= 0);
+        assert(cgroup);
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
         if (r < 0)
                 return r;
 
-        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
+        r = cg_shift_path(raw, root, &c);
         if (r < 0)
                 return r;
 
-        p = path_startswith(cg_process, cg_root);
-        if (p)
-                p--;
-        else
-                p = cg_process;
-
-        if (cgroup) {
-                char* c;
+        if (c == raw) {
+                *cgroup = raw;
+                raw = NULL;
+        } else {
+                char *n;
 
-                c = strdup(p);
-                if (!c) {
-                        free(cg_process);
+                n = strdup(c);
+                if (!n)
                         return -ENOMEM;
-                }
 
-                *cgroup = c;
+                *cgroup = n;
         }
 
-        if (root) {
-                cg_process[p-cg_process] = 0;
-                *root = cg_process;
-        } else
-                free(cg_process);
-
         return 0;
 }
 
 int cg_path_decode_unit(const char *cgroup, char **unit){
-        char *p, *e, *c, *s, *k;
+        char *e, *c, *s;
 
         assert(cgroup);
         assert(unit);
@@ -1109,28 +1149,10 @@ int cg_path_decode_unit(const char *cgroup, char **unit){
         c = strndupa(cgroup, e - cgroup);
         c = cg_unescape(c);
 
-        /* Could this be a valid unit name? */
-        if (!unit_name_is_valid(c, true))
+        if (!unit_name_is_valid(c, TEMPLATE_INVALID))
                 return -EINVAL;
 
-        if (!unit_name_is_template(c))
-                s = strdup(c);
-        else {
-                if (*e != '/')
-                        return -EINVAL;
-
-                e += strspn(e, "/");
-
-                p = strchrnul(e, '/');
-                k = strndupa(e, p - e);
-                k = cg_unescape(k);
-
-                if (!unit_name_is_valid(k, false))
-                        return -EINVAL;
-
-                s = strdup(k);
-        }
-
+        s = strdup(c);
         if (!s)
                 return -ENOMEM;
 
@@ -1178,23 +1200,9 @@ int cg_pid_get_unit(pid_t pid, char **unit) {
         return cg_path_get_unit(cgroup, unit);
 }
 
-static const char *skip_user(const char *p) {
-        size_t n;
-
-        assert(p);
-
-        p += strspn(p, "/");
-
-        n = strcspn(p, "/");
-        if (n <= 5 || memcmp(p + n - 5, ".user", 5) != 0)
-                return p;
-
-        p += n;
-        p += strspn(p, "/");
-
-        return p;
-}
-
+/**
+ * Skip session-*.scope, but require it to be there.
+ */
 static const char *skip_session(const char *p) {
         size_t n;
 
@@ -1203,7 +1211,7 @@ static const char *skip_session(const char *p) {
         p += strspn(p, "/");
 
         n = strcspn(p, "/");
-        if (n <= 8 || memcmp(p + n - 8, ".session", 8) != 0)
+        if (n < strlen("session-x.scope") || memcmp(p, "session-", 8) != 0 || memcmp(p + n - 6, ".scope", 6) != 0)
                 return NULL;
 
         p += n;
@@ -1212,7 +1220,10 @@ static const char *skip_session(const char *p) {
         return p;
 }
 
-static const char *skip_systemd_label(const char *p) {
+/**
+ * Skip user@*.service, but require it to be there.
+ */
+static const char *skip_user_manager(const char *p) {
         size_t n;
 
         assert(p);
@@ -1220,8 +1231,8 @@ static const char *skip_systemd_label(const char *p) {
         p += strspn(p, "/");
 
         n = strcspn(p, "/");
-        if (n < 8 || memcmp(p, "systemd-", 8) != 0)
-                return 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, "/");
@@ -1230,7 +1241,7 @@ static const char *skip_systemd_label(const char *p) {
 }
 
 int cg_path_get_user_unit(const char *path, char **unit) {
-        const char *e;
+        const char *e, *t;
 
         assert(path);
         assert(unit);
@@ -1242,16 +1253,17 @@ int cg_path_get_user_unit(const char *path, char **unit) {
         /* Skip slices, if there are any */
         e = skip_slices(path);
 
-        /* Skip the user name, if there is one */
-        e = skip_user(e);
-
-        /* Skip the session ID, require that there is one */
-        e = skip_session(e);
-        if (!e)
-                return -ENOENT;
-
-        /* Skip the systemd cgroup, if there is one */
-        e = skip_systemd_label(e);
+        /* 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);
 }
@@ -1270,32 +1282,18 @@ 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, *x;
-        char *s, *r;
-
-        assert(path);
-        assert(machine);
-
-        /* Skip slices, if there are any */
-        e = skip_slices(path);
-
-        n = strchrnul(e, '/');
-        if (e == n)
-                return -ENOENT;
-
-        s = strndupa(e, n - e);
-        s = cg_unescape(s);
+        _cleanup_free_ char *u = NULL, *sl = NULL;
+        int r;
 
-        x = endswith(s, ".machine");
-        if (!x)
-                return -ENOENT;
+        r = cg_path_get_unit(path, &u);
+        if (r < 0)
+                return r;
 
-        r = strndup(s, x - s);
-        if (!r)
+        sl = strjoin("/run/systemd/machines/unit:", u, NULL);
+        if (!sl)
                 return -ENOMEM;
 
-        *machine = r;
-        return 0;
+        return readlink_malloc(sl, machine);
 }
 
 int cg_pid_get_machine_name(pid_t pid, char **machine) {
@@ -1312,29 +1310,42 @@ 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;
+        const char *e, *n, *x;
         char *s;
+        size_t l;
 
         assert(path);
-        assert(session);
 
         /* Skip slices, if there are any */
         e = skip_slices(path);
 
-        /* Skip the user name, if there is one */
-        e = skip_user(e);
-
         n = strchrnul(e, '/');
-        if (n - e < 8)
+        if (e == n)
+                return -ENOENT;
+
+        s = strndupa(e, n - e);
+        s = cg_unescape(s);
+
+        x = startswith(s, "session-");
+        if (!x)
                 return -ENOENT;
-        if (memcmp(n - 8, ".session", 8) != 0)
+        if (!endswith(x, ".scope"))
                 return -ENOENT;
 
-        s = strndup(e, n - e - 8);
-        if (!s)
-                return -ENOMEM;
+        l = strlen(x);
+        if (l <= 6)
+                return -ENOENT;
+
+        if (session) {
+                char *r;
+
+                r = strndup(x, l - 6);
+                if (!r)
+                        return -ENOMEM;
+
+                *session = r;
+        }
 
-        *session = s;
         return 0;
 }
 
@@ -1342,8 +1353,6 @@ int cg_pid_get_session(pid_t pid, char **session) {
         _cleanup_free_ char *cgroup = NULL;
         int r;
 
-        assert(session);
-
         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
         if (r < 0)
                 return r;
@@ -1352,34 +1361,42 @@ int cg_pid_get_session(pid_t pid, char **session) {
 }
 
 int cg_path_get_owner_uid(const char *path, uid_t *uid) {
-        const char *e, *n;
+        _cleanup_free_ char *slice = NULL;
+        const char *start, *end;
         char *s;
+        uid_t u;
+        int r;
 
         assert(path);
-        assert(uid);
 
-        /* Skip slices, if there are any */
-        e = skip_slices(path);
+        r = cg_path_get_slice(path, &slice);
+        if (r < 0)
+                return r;
 
-        n = strchrnul(e, '/');
-        if (n - e < 5)
+        start = startswith(slice, "user-");
+        if (!start)
                 return -ENOENT;
-        if (memcmp(n - 5, ".user", 5) != 0)
+        end = endswith(slice, ".slice");
+        if (!end)
                 return -ENOENT;
 
-        s = strndupa(e, n - e - 5);
+        s = strndupa(start, end - start);
         if (!s)
-                return -ENOMEM;
+                return -ENOENT;
+
+        if (parse_uid(s, &u) < 0)
+                return -EIO;
 
-        return parse_uid(s, uid);
+        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;
 
-        assert(uid);
-
         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
         if (r < 0)
                 return r;
@@ -1434,35 +1451,6 @@ int cg_pid_get_slice(pid_t pid, char **slice) {
         return cg_path_get_slice(cgroup, slice);
 }
 
-int cg_controller_from_attr(const char *attr, char **controller) {
-        const char *dot;
-        char *c;
-
-        assert(attr);
-        assert(controller);
-
-        if (!filename_is_safe(attr))
-                return -EINVAL;
-
-        dot = strchr(attr, '.');
-        if (!dot) {
-                *controller = NULL;
-                return 0;
-        }
-
-        c = strndup(attr, dot - attr);
-        if (!c)
-                return -ENOMEM;
-
-        if (!cg_controller_is_valid(c, false)) {
-                free(c);
-                return -EINVAL;
-        }
-
-        *controller = c;
-        return 1;
-}
-
 char *cg_escape(const char *p) {
         bool need_prefix = false;
 
@@ -1521,9 +1509,7 @@ char *cg_unescape(const char *p) {
 }
 
 #define CONTROLLER_VALID                        \
-        "0123456789"                            \
-        "abcdefghijklmnopqrstuvwxyz"            \
-        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
+        DIGITS LETTERS                          \
         "_"
 
 bool cg_controller_is_valid(const char *p, bool allow_named) {
@@ -1558,7 +1544,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
         assert(unit);
         assert(ret);
 
-        if (!unit_name_is_valid(unit, false))
+        if (!unit_name_is_valid(unit, TEMPLATE_INVALID))
                 return -EINVAL;
 
         if (!endswith(unit, ".slice"))
@@ -1575,7 +1561,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
 
                 strcpy(stpncpy(n, p, dash - p), ".slice");
 
-                if (!unit_name_is_valid(n, false))
+                if (!unit_name_is_valid(n, TEMPLATE_INVALID))
                         return -EINVAL;
 
                 escaped = cg_escape(n);
@@ -1619,7 +1605,7 @@ static const char mask_names[] =
         "memory\0"
         "devices\0";
 
-int cg_create_with_mask(CGroupControllerMask mask, const char *path) {
+int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
@@ -1635,85 +1621,84 @@ int cg_create_with_mask(CGroupControllerMask mask, const char *path) {
 
         /* Then, do the same in the other hierarchies */
         NULSTR_FOREACH(n, mask_names) {
-                if (bit & mask)
+                if (mask & bit)
                         cg_create(n, path);
-                else
+                else if (supported & bit)
                         cg_trim(n, path, true);
 
                 bit <<= 1;
         }
 
-        return r;
+        return 0;
 }
 
-int cg_attach_with_mask(CGroupControllerMask mask, const char *path, pid_t pid) {
+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 (bit & mask)
-                        cg_attach(n, path, pid);
-                else {
-                        char prefix[strlen(path) + 1], *slash;
-
-                        /* OK, this one is a bit harder... Now we need
-                         * to add to the closest parent cgroup we
-                         * can find */
-                        strcpy(prefix, path);
-                        while ((slash = strrchr(prefix, '/'))) {
-                                int q;
-                                *slash = 0;
-
-                                q = cg_attach(n, prefix, pid);
-                                if (q >= 0)
-                                        break;
-                        }
-                }
+                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_with_mask(CGroupControllerMask mask, const char *from, const char *to) {
+int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
 
-        if (path_equal(from, to))
-                return 0;
-
-        r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true);
+        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 (bit & mask)
-                        cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, to, n, to, false, false);
-                else {
-                        char prefix[strlen(to) + 1], *slash;
+                if (supported & bit) {
+                        const char *p = NULL;
 
-                        strcpy(prefix, to);
-                        while ((slash = strrchr(prefix, '/'))) {
-                                int q;
+                        if (to_callback)
+                                p = to_callback(bit, userdata);
 
-                                *slash = 0;
+                        if (!p)
+                                p = to;
 
-                                q = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, to, n, prefix, false, false);
-                                if (q >= 0)
-                                        break;
-                        }
+                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, p, false, false);
                 }
 
                 bit <<= 1;
         }
 
-        return r;
+        return 0;
 }
 
-int cg_trim_with_mask(CGroupControllerMask mask, const char *path, bool delete_root) {
+int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
@@ -1723,13 +1708,13 @@ int cg_trim_with_mask(CGroupControllerMask mask, const char *path, bool delete_r
                 return r;
 
         NULSTR_FOREACH(n, mask_names) {
-                if (bit & mask)
+                if (supported & bit)
                         cg_trim(n, path, delete_root);
 
                 bit <<= 1;
         }
 
-        return r;
+        return 0;
 }
 
 CGroupControllerMask cg_mask_supported(void) {