chiark / gitweb /
Revert "cgroup.c: check return value of unit_realize_cgroup_now()"
[elogind.git] / src / core / cgroup.c
index 1f6139e25f752176b2d19781c1253c8e608f8dc9..5a1c3adacd19af3f8ff2c67ebcb98ea7ab2e53cd 100644 (file)
 /***
   This file is part of systemd.
 
-  Copyright 2010 Lennart Poettering
+  Copyright 2013 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.
 
   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  General Public License for more details.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <errno.h>
-#include <assert.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <signal.h>
-#include <sys/mount.h>
 #include <fcntl.h>
 
-#include "cgroup.h"
+#include "path-util.h"
+#include "special.h"
 #include "cgroup-util.h"
-#include "log.h"
+#include "cgroup.h"
 
-int cgroup_bonding_realize(CGroupBonding *b) {
-        int r;
+void cgroup_context_init(CGroupContext *c) {
+        assert(c);
+
+        /* Initialize everything to the kernel defaults, assuming the
+         * structure is preinitialized to 0 */
+
+        c->cpu_shares = 1024;
+        c->memory_limit = c->memory_soft_limit = (uint64_t) -1;
+        c->blockio_weight = 1000;
+}
+
+void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) {
+        assert(c);
+        assert(a);
+
+        LIST_REMOVE(CGroupDeviceAllow, device_allow, c->device_allow, a);
+        free(a->path);
+        free(a);
+}
 
+void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) {
+        assert(c);
+        assert(w);
+
+        LIST_REMOVE(CGroupBlockIODeviceWeight, device_weights, c->blockio_device_weights, w);
+        free(w->path);
+        free(w);
+}
+
+void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b) {
+        assert(c);
         assert(b);
-        assert(b->path);
-        assert(b->controller);
 
-        r = cg_create(b->controller, b->path);
+        LIST_REMOVE(CGroupBlockIODeviceBandwidth, device_bandwidths, c->blockio_device_bandwidths, b);
+        free(b->path);
+        free(b);
+}
+
+void cgroup_context_done(CGroupContext *c) {
+        assert(c);
+
+        while (c->blockio_device_weights)
+                cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights);
+
+        while (c->blockio_device_bandwidths)
+                cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths);
+
+        while (c->device_allow)
+                cgroup_context_free_device_allow(c, c->device_allow);
+}
+
+void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
+        CGroupBlockIODeviceBandwidth *b;
+        CGroupBlockIODeviceWeight *w;
+        CGroupDeviceAllow *a;
+
+        assert(c);
+        assert(f);
+
+        prefix = strempty(prefix);
+
+        fprintf(f,
+                "%sCPUAccounting=%s\n"
+                "%sBlockIOAccounting=%s\n"
+                "%sMemoryAccounting=%s\n"
+                "%sCPUShares=%lu\n"
+                "%sBlockIOWeight%lu\n"
+                "%sMemoryLimit=%" PRIu64 "\n"
+                "%sMemorySoftLimit=%" PRIu64 "\n"
+                "%sDevicePolicy=%s\n",
+                prefix, yes_no(c->cpu_accounting),
+                prefix, yes_no(c->blockio_accounting),
+                prefix, yes_no(c->memory_accounting),
+                prefix, c->cpu_shares,
+                prefix, c->blockio_weight,
+                prefix, c->memory_limit,
+                prefix, c->memory_soft_limit,
+                prefix, cgroup_device_policy_to_string(c->device_policy));
+
+        LIST_FOREACH(device_allow, a, c->device_allow)
+                fprintf(f,
+                        "%sDeviceAllow=%s %s%s%s\n",
+                        prefix,
+                        a->path,
+                        a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : "");
+
+        LIST_FOREACH(device_weights, w, c->blockio_device_weights)
+                fprintf(f,
+                        "%sBlockIODeviceWeight=%s %lu",
+                        prefix,
+                        w->path,
+                        w->weight);
+
+        LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
+                char buf[FORMAT_BYTES_MAX];
+
+                fprintf(f,
+                        "%s%s=%s %s\n",
+                        prefix,
+                        b->read ? "BlockIOReadBandwidth" : "BlockIOWriteBandwidth",
+                        b->path,
+                        format_bytes(buf, sizeof(buf), b->bandwidth));
+        }
+}
+
+static int lookup_blkio_device(const char *p, dev_t *dev) {
+        struct stat st;
+        int r;
+
+        assert(p);
+        assert(dev);
+
+        r = stat(p, &st);
         if (r < 0) {
-                log_warning("Failed to create cgroup %s:%s: %s", b->controller, b->path, strerror(-r));
-                return r;
+                log_warning("Couldn't stat device %s: %m", p);
+                return -errno;
         }
 
-        b->realized = true;
+        if (S_ISBLK(st.st_mode))
+                *dev = st.st_rdev;
+        else if (major(st.st_dev) != 0) {
+                /* If this is not a device node then find the block
+                 * device this file is stored on */
+                *dev = st.st_dev;
+
+                /* If this is a partition, try to get the originating
+                 * block device */
+                block_get_whole_disk(*dev, dev);
+        } else {
+                log_warning("%s is not a block device and file system block device cannot be determined or is not local.", p);
+                return -ENODEV;
+        }
 
         return 0;
 }
 
-int cgroup_bonding_realize_list(CGroupBonding *first) {
-        CGroupBonding *b;
+static int whitelist_device(const char *path, const char *node, const char *acc) {
+        char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4];
+        struct stat st;
         int r;
 
-        LIST_FOREACH(by_unit, b, first)
-                if ((r = cgroup_bonding_realize(b)) < 0 && b->essential)
-                        return r;
+        assert(path);
+        assert(acc);
 
-        return 0;
+        if (stat(node, &st) < 0) {
+                log_warning("Couldn't stat device %s", node);
+                return -errno;
+        }
+
+        if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
+                log_warning("%s is not a device.", node);
+                return -ENODEV;
+        }
+
+        sprintf(buf,
+                "%c %u:%u %s",
+                S_ISCHR(st.st_mode) ? 'c' : 'b',
+                major(st.st_rdev), minor(st.st_rdev),
+                acc);
+
+        r = cg_set_attribute("devices", path, "devices.allow", buf);
+        if (r < 0)
+                log_warning("Failed to set devices.allow on %s: %s", path, strerror(-r));
+
+        return r;
 }
 
-void cgroup_bonding_free(CGroupBonding *b, bool trim) {
-        assert(b);
+void cgroup_context_apply(CGroupContext *c, CGroupControllerMask mask, const char *path) {
+        int r;
+
+        assert(c);
+        assert(path);
 
-        if (b->unit) {
-                CGroupBonding *f;
+        if (mask == 0)
+                return;
 
-                LIST_REMOVE(CGroupBonding, by_unit, b->unit->cgroup_bondings, b);
+        if (mask & CGROUP_CPU) {
+                char buf[DECIMAL_STR_MAX(unsigned long) + 1];
 
-                if (streq(b->controller, SYSTEMD_CGROUP_CONTROLLER)) {
-                        assert_se(f = hashmap_get(b->unit->manager->cgroup_bondings, b->path));
-                        LIST_REMOVE(CGroupBonding, by_path, f, b);
+                sprintf(buf, "%lu\n", c->cpu_shares);
+                r = cg_set_attribute("cpu", path, "cpu.shares", buf);
+                if (r < 0)
+                        log_warning("Failed to set cpu.shares on %s: %s", path, strerror(-r));
+        }
+
+        if (mask & CGROUP_BLKIO) {
+                char buf[MAX3(DECIMAL_STR_MAX(unsigned long)+1,
+                              DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(unsigned long)*1,
+                              DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1)];
+                CGroupBlockIODeviceWeight *w;
+                CGroupBlockIODeviceBandwidth *b;
+
+                sprintf(buf, "%lu\n", c->blockio_weight);
+                r = cg_set_attribute("blkio", path, "blkio.weight", buf);
+                if (r < 0)
+                        log_warning("Failed to set blkio.weight on %s: %s", path, strerror(-r));
+
+                /* FIXME: no way to reset this list */
+                LIST_FOREACH(device_weights, w, c->blockio_device_weights) {
+                        dev_t dev;
+
+                        r = lookup_blkio_device(w->path, &dev);
+                        if (r < 0)
+                                continue;
 
-                        if (f)
-                                hashmap_replace(b->unit->manager->cgroup_bondings, b->path, f);
-                        else
-                                hashmap_remove(b->unit->manager->cgroup_bondings, b->path);
+                        sprintf(buf, "%u:%u %lu", major(dev), minor(dev), w->weight);
+                        r = cg_set_attribute("blkio", path, "blkio.weight_device", buf);
+                        if (r < 0)
+                                log_error("Failed to set blkio.weight_device on %s: %s", path, strerror(-r));
+                }
+
+                /* FIXME: no way to reset this list */
+                LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
+                        const char *a;
+                        dev_t dev;
+
+                        r = lookup_blkio_device(b->path, &dev);
+                        if (r < 0)
+                                continue;
+
+                        a = b->read ? "blkio.throttle.read_bps_device" : "blkio.throttle.write_bps_device";
+
+                        sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), b->bandwidth);
+                        r = cg_set_attribute("blkio", path, a, buf);
+                        if (r < 0)
+                                log_error("Failed to set %s on %s: %s", a, path, strerror(-r));
                 }
         }
 
-        if (b->realized && b->ours && trim)
-                cg_trim(b->controller, b->path, false);
+        if (mask & CGROUP_MEMORY) {
+                char buf[DECIMAL_STR_MAX(uint64_t) + 1];
 
-        free(b->controller);
-        free(b->path);
-        free(b);
-}
+                sprintf(buf, "%" PRIu64 "\n", c->memory_limit);
+                r = cg_set_attribute("memory", path, "memory.limit_in_bytes", buf);
+                if (r < 0)
+                        log_error("Failed to set memory.limit_in_bytes on %s: %s", path, strerror(-r));
 
-void cgroup_bonding_free_list(CGroupBonding *first, bool remove_or_trim) {
-        CGroupBonding *b, *n;
+                sprintf(buf, "%" PRIu64 "\n", c->memory_soft_limit);
+                cg_set_attribute("memory", path, "memory.soft_limit_in_bytes", buf);
+                if (r < 0)
+                        log_error("Failed to set memory.limit_in_bytes on %s: %s", path, strerror(-r));
+        }
 
-        LIST_FOREACH_SAFE(by_unit, b, n, first)
-                cgroup_bonding_free(b, remove_or_trim);
-}
+        if (mask & CGROUP_DEVICE) {
+                CGroupDeviceAllow *a;
 
-void cgroup_bonding_trim(CGroupBonding *b, bool delete_root) {
-        assert(b);
+                if (c->device_allow || c->device_policy != CGROUP_AUTO)
+                        r = cg_set_attribute("devices", path, "devices.deny", "a");
+                else
+                        r = cg_set_attribute("devices", path, "devices.allow", "a");
+                if (r < 0)
+                        log_error("Failed to reset devices.list on %s: %s", path, strerror(-r));
 
-        if (b->realized && b->ours)
-                cg_trim(b->controller, b->path, delete_root);
-}
+                if (c->device_policy == CGROUP_CLOSED ||
+                    (c->device_policy == CGROUP_AUTO && c->device_allow)) {
+                        static const char auto_devices[] =
+                                "/dev/null\0" "rw\0"
+                                "/dev/zero\0" "rw\0"
+                                "/dev/full\0" "rw\0"
+                                "/dev/random\0" "rw\0"
+                                "/dev/urandom\0" "rw\0";
 
-void cgroup_bonding_trim_list(CGroupBonding *first, bool delete_root) {
-        CGroupBonding *b;
+                        const char *x, *y;
 
-        LIST_FOREACH(by_unit, b, first)
-                cgroup_bonding_trim(b, delete_root);
-}
+                        NULSTR_FOREACH_PAIR(x, y, auto_devices)
+                                whitelist_device(path, x, y);
+                }
 
-int cgroup_bonding_install(CGroupBonding *b, pid_t pid) {
-        int r;
+                LIST_FOREACH(device_allow, a, c->device_allow) {
+                        char acc[4];
+                        unsigned k = 0;
 
-        assert(b);
-        assert(pid >= 0);
+                        if (a->r)
+                                acc[k++] = 'r';
+                        if (a->w)
+                                acc[k++] = 'w';
+                        if (a->m)
+                                acc[k++] = 'm';
 
-        if ((r = cg_create_and_attach(b->controller, b->path, pid)) < 0)
-                return r;
+                        if (k == 0)
+                                continue;
 
-        b->realized = true;
-        return 0;
+                        acc[k++] = 0;
+                        whitelist_device(path, a->path, acc);
+                }
+        }
 }
 
-int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) {
-        CGroupBonding *b;
-        int r;
+CGroupControllerMask cgroup_context_get_mask(CGroupContext *c) {
+        CGroupControllerMask mask = 0;
 
-        LIST_FOREACH(by_unit, b, first)
-                if ((r = cgroup_bonding_install(b, pid)) < 0 && b->essential)
-                        return r;
+        /* Figure out which controllers we need */
 
-        return 0;
+        if (c->cpu_accounting || c->cpu_shares != 1024)
+                mask |= CGROUP_CPUACCT | CGROUP_CPU;
+
+        if (c->blockio_accounting ||
+            c->blockio_weight != 1000 ||
+            c->blockio_device_weights ||
+            c->blockio_device_bandwidths)
+                mask |= CGROUP_BLKIO;
+
+        if (c->memory_accounting ||
+            c->memory_limit != (uint64_t) -1 ||
+            c->memory_soft_limit != (uint64_t) -1)
+                mask |= CGROUP_MEMORY;
+
+        if (c->device_allow || c->device_policy != CGROUP_AUTO)
+                mask |= CGROUP_DEVICE;
+
+        return mask;
 }
 
-int cgroup_bonding_set_group_access(CGroupBonding *b, mode_t mode, uid_t uid, gid_t gid) {
-        assert(b);
+static CGroupControllerMask unit_get_cgroup_mask(Unit *u) {
+        CGroupContext *c;
 
-        if (!b->realized)
-                return -EINVAL;
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
 
-        return cg_set_group_access(b->controller, b->path, mode, uid, gid);
+        return cgroup_context_get_mask(c);
 }
 
-int cgroup_bonding_set_group_access_list(CGroupBonding *first, mode_t mode, uid_t uid, gid_t gid) {
-        CGroupBonding *b;
-        int r;
+static CGroupControllerMask unit_get_members_mask(Unit *u) {
+        CGroupControllerMask mask = 0;
+        Unit *m;
+        Iterator i;
 
-        LIST_FOREACH(by_unit, b, first) {
-                r = cgroup_bonding_set_group_access(b, mode, uid, gid);
-                if (r < 0)
-                        return r;
+        assert(u);
+
+        SET_FOREACH(m, u->dependencies[UNIT_BEFORE], i) {
+
+                if (UNIT_DEREF(m->slice) != u)
+                        continue;
+
+                mask |= unit_get_cgroup_mask(m) | unit_get_members_mask(m);
         }
 
-        return 0;
+        return mask;
 }
 
-int cgroup_bonding_set_task_access(CGroupBonding *b, mode_t mode, uid_t uid, gid_t gid, int sticky) {
-        assert(b);
+static CGroupControllerMask unit_get_siblings_mask(Unit *u) {
+        assert(u);
 
-        if (!b->realized)
-                return -EINVAL;
+        if (!UNIT_ISSET(u->slice))
+                return 0;
 
-        return cg_set_task_access(b->controller, b->path, mode, uid, gid, sticky);
+        /* Sibling propagation is only relevant for weight-based
+         * controllers, so let's mask out everything else */
+        return unit_get_members_mask(UNIT_DEREF(u->slice)) &
+                (CGROUP_CPU|CGROUP_BLKIO|CGROUP_CPUACCT);
 }
 
-int cgroup_bonding_set_task_access_list(CGroupBonding *first, mode_t mode, uid_t uid, gid_t gid, int sticky) {
-        CGroupBonding *b;
+static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) {
+        char *path = NULL;
         int r;
 
-        LIST_FOREACH(by_unit, b, first) {
-                r = cgroup_bonding_set_task_access(b, mode, uid, gid, sticky);
+        assert(u);
+
+        path = unit_default_cgroup_path(u);
+        if (!path)
+                return -ENOMEM;
+
+        r = hashmap_put(u->manager->cgroup_unit, path, u);
+        if (r < 0)
+                return r;
+
+        /* First, create our own group */
+        r = cg_create_with_mask(mask, path);
+        if (r < 0)
+                log_error("Failed to create cgroup %s: %s", path, strerror(-r));
+
+        /* Then, possibly move things over */
+        if (u->cgroup_path && !streq(path, u->cgroup_path)) {
+                r = cg_migrate_with_mask(mask, u->cgroup_path, path);
                 if (r < 0)
-                        return r;
+                        log_error("Failed to migrate cgroup %s: %s", path, strerror(-r));
         }
 
+        /* And remember the new data */
+        free(u->cgroup_path);
+        u->cgroup_path = path;
+        u->cgroup_realized = true;
+        u->cgroup_mask = mask;
+
         return 0;
 }
 
-int cgroup_bonding_kill(CGroupBonding *b, int sig, bool sigcont, Set *s) {
-        assert(b);
-        assert(sig >= 0);
+static int unit_realize_cgroup_now(Unit *u) {
+        CGroupControllerMask mask;
+
+        assert(u);
+
+        if (u->in_cgroup_queue) {
+                LIST_REMOVE(Unit, cgroup_queue, u->manager->cgroup_queue, u);
+                u->in_cgroup_queue = false;
+        }
+
+        mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
+        mask &= u->manager->cgroup_supported;
 
-        /* Don't kill cgroups that aren't ours */
-        if (!b->ours)
+        if (u->cgroup_realized &&
+            u->cgroup_mask == mask)
                 return 0;
 
-        return cg_kill_recursive(b->controller, b->path, sig, sigcont, true, false, s);
+        /* First, realize parents */
+        if (UNIT_ISSET(u->slice))
+                unit_realize_cgroup_now(UNIT_DEREF(u->slice));
+
+        /* And then do the real work */
+        return unit_create_cgroups(u, mask);
 }
 
-int cgroup_bonding_kill_list(CGroupBonding *first, int sig, bool sigcont, Set *s) {
-        CGroupBonding *b;
-        Set *allocated_set = NULL;
-        int ret = -EAGAIN, r;
+static void unit_add_to_cgroup_queue(Unit *u) {
 
-        if (!first)
-                return 0;
+        if (u->in_cgroup_queue)
+                return;
+
+        LIST_PREPEND(Unit, cgroup_queue, u->manager->cgroup_queue, u);
+        u->in_cgroup_queue = true;
+}
+
+unsigned manager_dispatch_cgroup_queue(Manager *m) {
+        Unit *i;
+        unsigned n = 0;
+
+        while ((i = m->cgroup_queue)) {
+                assert(i->in_cgroup_queue);
+
+                if (unit_realize_cgroup_now(i) >= 0)
+                        cgroup_context_apply(unit_get_cgroup_context(i), i->cgroup_mask, i->cgroup_path);
+
+                n++;
+        }
+
+        return n;
+}
+
+static void unit_queue_siblings(Unit *u) {
+        Unit *slice;
 
-        if (!s)
-                if (!(s = allocated_set = set_new(trivial_hash_func, trivial_compare_func)))
-                        return -ENOMEM;
+        /* This adds the siblings of the specified unit and the
+         * siblings of all parent units to the cgroup queue. (But
+         * neither the specified unit itself nor the parents.) */
 
-        LIST_FOREACH(by_unit, b, first) {
-                if ((r = cgroup_bonding_kill(b, sig, sigcont, s)) < 0) {
-                        if (r == -EAGAIN || r == -ESRCH)
+        while ((slice = UNIT_DEREF(u->slice))) {
+                Iterator i;
+                Unit *m;
+
+                SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
+                        if (m == u)
+                                continue;
+
+                        if (UNIT_DEREF(m->slice) != slice)
                                 continue;
 
-                        ret = r;
-                        goto finish;
+                        unit_add_to_cgroup_queue(m);
                 }
 
-                if (ret < 0 || r > 0)
-                        ret = r;
+                u = slice;
         }
+}
+
+int unit_realize_cgroup(Unit *u) {
+        CGroupContext *c;
+        int r;
+
+        assert(u);
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
+
+        /* So, here's the deal: when realizing the cgroups for this
+         * unit, we need to first create all parents, but there's more
+         * actually: for the weight-based controllers we also need to
+         * make sure that all our siblings (i.e. units that are in the
+         * same slice as we are) have cgroup too. Otherwise things
+         * would become very uneven as each of their processes would
+         * get as much resources as all our group together. This call
+         * will synchronously create the parent cgroups, but will
+         * defer work on the siblings to the next event loop
+         * iteration. */
+
+        /* Add all sibling slices to the cgroup queue. */
+        unit_queue_siblings(u);
+
+        /* And realize this one now */
+        r = unit_realize_cgroup_now(u);
 
-finish:
-        if (allocated_set)
-                set_free(allocated_set);
+        /* And apply the values */
+        if (r >= 0)
+                cgroup_context_apply(c, u->cgroup_mask, u->cgroup_path);
 
-        return ret;
+        return r;
 }
 
-/* Returns 1 if the group is empty, 0 if it is not, -EAGAIN if we
- * cannot know */
-int cgroup_bonding_is_empty(CGroupBonding *b) {
+void unit_destroy_cgroup(Unit *u) {
         int r;
 
-        assert(b);
+        assert(u);
 
-        if ((r = cg_is_empty_recursive(b->controller, b->path, true)) < 0)
-                return r;
+        if (!u->cgroup_path)
+                return;
+
+        r = cg_trim_with_mask(u->cgroup_mask, u->cgroup_path, !unit_has_name(u, SPECIAL_ROOT_SLICE));
+        if (r < 0)
+                log_debug("Failed to destroy cgroup %s: %s", u->cgroup_path, strerror(-r));
 
-        /* If it is empty it is empty */
-        if (r > 0)
-                return 1;
+        hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
+
+        free(u->cgroup_path);
+        u->cgroup_path = NULL;
+        u->cgroup_realized = false;
+        u->cgroup_mask = 0;
 
-        /* It's not only us using this cgroup, so we just don't know */
-        return b->ours ? 0 : -EAGAIN;
 }
 
-int cgroup_bonding_is_empty_list(CGroupBonding *first) {
-        CGroupBonding *b;
+pid_t unit_search_main_pid(Unit *u) {
+        _cleanup_fclose_ FILE *f = NULL;
+        pid_t pid = 0, npid, mypid;
 
-        LIST_FOREACH(by_unit, b, first) {
-                int r;
+        assert(u);
 
-                if ((r = cgroup_bonding_is_empty(b)) < 0) {
-                        /* If this returned -EAGAIN, then we don't know if the
-                         * group is empty, so let's see if another group can
-                         * tell us */
+        if (!u->cgroup_path)
+                return 0;
+
+        if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f) < 0)
+                return 0;
+
+        mypid = getpid();
+        while (cg_read_pid(f, &npid) > 0)  {
+                pid_t ppid;
 
-                        if (r != -EAGAIN)
-                                return r;
-                } else
-                        return r;
+                if (npid == pid)
+                        continue;
+
+                /* Ignore processes that aren't our kids */
+                if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
+                        continue;
+
+                if (pid != 0) {
+                        /* Dang, there's more than one daemonized PID
+                        in this group, so we don't know what process
+                        is the main process. */
+                        pid = 0;
+                        break;
+                }
+
+                pid = npid;
         }
 
-        return -EAGAIN;
+        return pid;
 }
 
 int manager_setup_cgroup(Manager *m) {
-        char *current = NULL, *path = NULL;
+        _cleanup_free_ char *path = NULL;
         int r;
-        char suffix[32];
+        char *e, *a;
 
         assert(m);
 
@@ -271,286 +595,160 @@ int manager_setup_cgroup(Manager *m) {
         }
 
         /* 1. Determine hierarchy */
-        if ((r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &current)) < 0) {
+        free(m->cgroup_root);
+        m->cgroup_root = NULL;
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
+        if (r < 0) {
                 log_error("Cannot determine cgroup we are running in: %s", strerror(-r));
-                goto finish;
+                return r;
         }
 
-        if (m->running_as == MANAGER_SYSTEM)
-                strcpy(suffix, "/system");
-        else {
-                snprintf(suffix, sizeof(suffix), "/systemd-%lu", (unsigned long) getpid());
-                char_array_0(suffix);
+        /* Already in /system.slice? If so, let's cut this off again */
+        if (m->running_as == SYSTEMD_SYSTEM) {
+                e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
+                if (e)
+                        *e = 0;
         }
 
-        free(m->cgroup_hierarchy);
-        if (endswith(current, suffix)) {
-                /* We probably got reexecuted and can continue to use our root cgroup */
-                m->cgroup_hierarchy = current;
-                current = NULL;
-
-        } else {
-                /* We need a new root cgroup */
-                m->cgroup_hierarchy = NULL;
-                if (asprintf(&m->cgroup_hierarchy, "%s%s", streq(current, "/") ? "" : current, suffix) < 0) {
-                        log_error("Out of memory");
-                        r = -ENOMEM;
-                        goto finish;
-                }
-        }
+        /* And make sure to store away the root value without trailing
+         * slash, even for the root dir, so that we can easily prepend
+         * it everywhere. */
+        if (streq(m->cgroup_root, "/"))
+                m->cgroup_root[0] = 0;
 
         /* 2. Show data */
-        if ((r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, NULL, &path)) < 0) {
+        r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
+        if (r < 0) {
                 log_error("Cannot find cgroup mount point: %s", strerror(-r));
-                goto finish;
+                return r;
         }
 
         log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
 
         /* 3. Install agent */
-        if ((r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH)) < 0)
-                log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
-        else if (r > 0)
-                log_debug("Installed release agent.");
-        else
-                log_debug("Release agent already installed.");
-
-        /* 4. Realize the group */
-        if ((r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, 0)) < 0) {
+        if (m->running_as == SYSTEMD_SYSTEM) {
+                r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
+                if (r < 0)
+                        log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
+                else if (r > 0)
+                        log_debug("Installed release agent.");
+                else
+                        log_debug("Release agent already installed.");
+        }
+
+        /* 4. Realize the system slice and put us in there */
+        if (m->running_as == SYSTEMD_SYSTEM) {
+                a = strappenda(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
+                r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, a, 0);
+        } else
+                r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, 0);
+        if (r < 0) {
                 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
-                goto finish;
+                return r;
         }
 
         /* 5. And pin it, so that it cannot be unmounted */
         if (m->pin_cgroupfs_fd >= 0)
                 close_nointr_nofail(m->pin_cgroupfs_fd);
 
-        if ((m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK)) < 0) {
+        m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
+        if (r < 0) {
                 log_error("Failed to open pin file: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
-        log_debug("Created root group.");
-
-finish:
-        free(current);
-        free(path);
+        /* 6. Figure out which controllers are supported */
+        m->cgroup_supported = cg_mask_supported();
 
-        return r;
+        return 0;
 }
 
 void manager_shutdown_cgroup(Manager *m, bool delete) {
         assert(m);
 
-        if (delete && m->cgroup_hierarchy)
-                cg_delete(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy);
+        /* We can't really delete the group, since we are in it. But
+         * let's trim it. */
+        if (delete && m->cgroup_root)
+                cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
 
         if (m->pin_cgroupfs_fd >= 0) {
                 close_nointr_nofail(m->pin_cgroupfs_fd);
                 m->pin_cgroupfs_fd = -1;
         }
 
-        free(m->cgroup_hierarchy);
-        m->cgroup_hierarchy = NULL;
+        free(m->cgroup_root);
+        m->cgroup_root = NULL;
 }
 
-int cgroup_bonding_get(Manager *m, const char *cgroup, CGroupBonding **bonding) {
-        CGroupBonding *b;
+Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
         char *p;
+        Unit *u;
 
         assert(m);
         assert(cgroup);
-        assert(bonding);
-
-        b = hashmap_get(m->cgroup_bondings, cgroup);
-        if (b) {
-                *bonding = b;
-                return 1;
-        }
 
-        p = strdup(cgroup);
-        if (!p)
-                return -ENOMEM;
+        u = hashmap_get(m->cgroup_unit, cgroup);
+        if (u)
+                return u;
 
+        p = strdupa(cgroup);
         for (;;) {
                 char *e;
 
                 e = strrchr(p, '/');
-                if (!e || e == p) {
-                        free(p);
-                        *bonding = NULL;
-                        return 0;
-                }
+                if (e == p || !e)
+                        return NULL;
 
                 *e = 0;
 
-                b = hashmap_get(m->cgroup_bondings, p);
-                if (b) {
-                        free(p);
-                        *bonding = b;
-                        return 1;
-                }
+                u = hashmap_get(m->cgroup_unit, p);
+                if (u)
+                        return u;
         }
 }
 
-int cgroup_notify_empty(Manager *m, const char *group) {
-        CGroupBonding *l, *b;
+Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
+        _cleanup_free_ char *cgroup = NULL;
         int r;
 
-        assert(m);
-        assert(group);
-
-        r = cgroup_bonding_get(m, group, &l);
-        if (r <= 0)
-                return r;
-
-        LIST_FOREACH(by_path, b, l) {
-                int t;
-
-                if (!b->unit)
-                        continue;
-
-                t = cgroup_bonding_is_empty_list(b);
-                if (t < 0) {
-
-                        /* If we don't know, we don't know */
-                        if (t != -EAGAIN)
-                                log_warning("Failed to check whether cgroup is empty: %s", strerror(errno));
-
-                        continue;
-                }
-
-                if (t > 0) {
-                        /* If it is empty, let's delete it */
-                        cgroup_bonding_trim_list(b->unit->cgroup_bondings, true);
-
-                        if (UNIT_VTABLE(b->unit)->cgroup_notify_empty)
-                                UNIT_VTABLE(b->unit)->cgroup_notify_empty(b->unit);
-                }
-        }
-
-        return 0;
-}
-
-Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) {
-        CGroupBonding *l, *b;
-        char *group = NULL;
-
         assert(m);
 
         if (pid <= 1)
                 return NULL;
 
-        if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &group) < 0)
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
+        if (r < 0)
                 return NULL;
 
-        l = hashmap_get(m->cgroup_bondings, group);
-
-        if (!l) {
-                char *slash;
-
-                while ((slash = strrchr(group, '/'))) {
-                        if (slash == group)
-                                break;
-
-                        *slash = 0;
-
-                        if ((l = hashmap_get(m->cgroup_bondings, group)))
-                                break;
-                }
-        }
-
-        free(group);
-
-        LIST_FOREACH(by_path, b, l) {
-
-                if (!b->unit)
-                        continue;
-
-                if (b->ours)
-                        return b->unit;
-        }
-
-        return NULL;
+        return manager_get_unit_by_cgroup(m, cgroup);
 }
 
-CGroupBonding *cgroup_bonding_find_list(CGroupBonding *first, const char *controller) {
-        CGroupBonding *b;
-
-        assert(controller);
-
-        LIST_FOREACH(by_unit, b, first)
-                if (streq(b->controller, controller))
-                        return b;
-
-        return NULL;
-}
-
-char *cgroup_bonding_to_string(CGroupBonding *b) {
-        char *r;
-
-        assert(b);
-
-        if (asprintf(&r, "%s:%s", b->controller, b->path) < 0)
-                return NULL;
-
-        return r;
-}
-
-pid_t cgroup_bonding_search_main_pid(CGroupBonding *b) {
-        FILE *f;
-        pid_t pid = 0, npid, mypid;
-
-        assert(b);
-
-        if (!b->ours)
-                return 0;
-
-        if (cg_enumerate_processes(b->controller, b->path, &f) < 0)
-                return 0;
-
-        mypid = getpid();
-
-        while (cg_read_pid(f, &npid) > 0)  {
-                pid_t ppid;
+int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
+        Unit *u;
+        int r;
 
-                if (npid == pid)
-                        continue;
+        assert(m);
+        assert(cgroup);
 
-                /* Ignore processes that aren't our kids */
-                if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
-                        continue;
+        u = manager_get_unit_by_cgroup(m, cgroup);
+        if (u) {
+                r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, true);
+                if (r > 0) {
+                        if (UNIT_VTABLE(u)->notify_cgroup_empty)
+                                UNIT_VTABLE(u)->notify_cgroup_empty(u);
 
-                if (pid != 0) {
-                        /* Dang, there's more than one daemonized PID
-                        in this group, so we don't know what process
-                        is the main process. */
-                        pid = 0;
-                        break;
+                        unit_add_to_gc_queue(u);
                 }
-
-                pid = npid;
         }
 
-        fclose(f);
-
-        return pid;
+        return 0;
 }
 
-pid_t cgroup_bonding_search_main_pid_list(CGroupBonding *first) {
-        CGroupBonding *b;
-        pid_t pid;
-
-        /* Try to find a main pid from this cgroup, but checking if
-         * there's only one PID in the cgroup and returning it. Later
-         * on we might want to add additional, smarter heuristics
-         * here. */
+static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
+        [CGROUP_AUTO] = "auto",
+        [CGROUP_CLOSED] = "closed",
+        [CGROUP_STRICT] = "strict",
+};
 
-        LIST_FOREACH(by_unit, b, first)
-                if ((pid = cgroup_bonding_search_main_pid(b)) != 0)
-                        return pid;
-
-        return 0;
-
-}
+DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);