chiark / gitweb /
[Patch 2/3] Add cgroups initialization and handling
authorSven Eden <yamakuzure@gmx.net>
Thu, 26 Jan 2017 07:21:20 +0000 (08:21 +0100)
committerSven Eden <yamakuzure@gmx.net>
Tue, 14 Mar 2017 09:23:02 +0000 (10:23 +0100)
Add a highly reduced src/core/cgroup.[hc] to enable elogind to setup
cgroups for proper usage.

Makefile.am
src/core/Makefile [new symlink]
src/core/cgroup.c [new file with mode: 0644]
src/core/cgroup.h [new file with mode: 0644]

index 2f9ec71..d84cfd6 100644 (file)
@@ -127,6 +127,7 @@ AM_CPPFLAGS = \
        -I $(top_srcdir)/src \
        -I $(top_builddir)/src/basic \
        -I $(top_srcdir)/src/basic \
+       -I $(top_srcdir)/src/core \
        -I $(top_srcdir)/src/shared \
        -I $(top_builddir)/src/shared \
        -I $(top_srcdir)/src/login \
@@ -606,7 +607,9 @@ libelogind_core_la_SOURCES = \
        src/login/logind-seat-dbus.c \
        src/login/logind-user-dbus.c \
        src/login/logind-utmp.c \
-       src/login/logind-acl.h
+       src/login/logind-acl.h \
+       src/core/cgroup.h \
+       src/core/cgroup.c
 
 libelogind_core_la_LIBADD = \
        libshared.la
diff --git a/src/core/Makefile b/src/core/Makefile
new file mode 120000 (symlink)
index 0000000..d0b0e8e
--- /dev/null
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
new file mode 100644 (file)
index 0000000..9b0339a
--- /dev/null
@@ -0,0 +1,1556 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <fcntl.h>
+#include <fnmatch.h>
+
+#include "process-util.h"
+#include "path-util.h"
+#include "special.h"
+#include "cgroup-util.h"
+#include "cgroup.h"
+
+#define CGROUP_CPU_QUOTA_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC)
+
+void cgroup_context_init(CGroupContext *c) {
+        assert(c);
+
+        /* Initialize everything to the kernel defaults, assuming the
+         * structure is preinitialized to 0 */
+
+        c->cpu_shares = (unsigned long) -1;
+        c->startup_cpu_shares = (unsigned long) -1;
+        c->memory_limit = (uint64_t) -1;
+        c->blockio_weight = (unsigned long) -1;
+        c->startup_blockio_weight = (unsigned long) -1;
+
+        c->cpu_quota_per_sec_usec = USEC_INFINITY;
+}
+
+void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) {
+        assert(c);
+        assert(a);
+
+        LIST_REMOVE(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(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);
+
+        LIST_REMOVE(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);
+}
+
+/// UNNEEDED by elogind
+#if 0
+void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
+        CGroupBlockIODeviceBandwidth *b;
+        CGroupBlockIODeviceWeight *w;
+        CGroupDeviceAllow *a;
+        char u[FORMAT_TIMESPAN_MAX];
+
+        assert(c);
+        assert(f);
+
+        prefix = strempty(prefix);
+
+        fprintf(f,
+                "%sCPUAccounting=%s\n"
+                "%sBlockIOAccounting=%s\n"
+                "%sMemoryAccounting=%s\n"
+                "%sCPUShares=%lu\n"
+                "%sStartupCPUShares=%lu\n"
+                "%sCPUQuotaPerSecSec=%s\n"
+                "%sBlockIOWeight=%lu\n"
+                "%sStartupBlockIOWeight=%lu\n"
+                "%sMemoryLimit=%" PRIu64 "\n"
+                "%sDevicePolicy=%s\n"
+                "%sDelegate=%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->startup_cpu_shares,
+                prefix, format_timespan(u, sizeof(u), c->cpu_quota_per_sec_usec, 1),
+                prefix, c->blockio_weight,
+                prefix, c->startup_blockio_weight,
+                prefix, c->memory_limit,
+                prefix, cgroup_device_policy_to_string(c->device_policy),
+                prefix, yes_no(c->delegate));
+
+        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)
+                return log_warning_errno(errno, "Couldn't stat device %s: %m", p);
+
+        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;
+}
+
+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;
+
+        assert(path);
+        assert(acc);
+
+        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_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL) ? LOG_DEBUG : LOG_WARNING, r,
+                               "Failed to set devices.allow on %s: %m", path);
+
+        return r;
+}
+
+static int whitelist_major(const char *path, const char *name, char type, const char *acc) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char line[LINE_MAX];
+        bool good = false;
+        int r;
+
+        assert(path);
+        assert(acc);
+        assert(type == 'b' || type == 'c');
+
+        f = fopen("/proc/devices", "re");
+        if (!f)
+                return log_warning_errno(errno, "Cannot open /proc/devices to resolve %s (%c): %m", name, type);
+
+        FOREACH_LINE(line, f, goto fail) {
+                char buf[2+DECIMAL_STR_MAX(unsigned)+3+4], *p, *w;
+                unsigned maj;
+
+                truncate_nl(line);
+
+                if (type == 'c' && streq(line, "Character devices:")) {
+                        good = true;
+                        continue;
+                }
+
+                if (type == 'b' && streq(line, "Block devices:")) {
+                        good = true;
+                        continue;
+                }
+
+                if (isempty(line)) {
+                        good = false;
+                        continue;
+                }
+
+                if (!good)
+                        continue;
+
+                p = strstrip(line);
+
+                w = strpbrk(p, WHITESPACE);
+                if (!w)
+                        continue;
+                *w = 0;
+
+                r = safe_atou(p, &maj);
+                if (r < 0)
+                        continue;
+                if (maj <= 0)
+                        continue;
+
+                w++;
+                w += strspn(w, WHITESPACE);
+
+                if (fnmatch(name, w, 0) != 0)
+                        continue;
+
+                sprintf(buf,
+                        "%c %u:* %s",
+                        type,
+                        maj,
+                        acc);
+
+                r = cg_set_attribute("devices", path, "devices.allow", buf);
+                if (r < 0)
+                        log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to set devices.allow on %s: %m", path);
+        }
+
+        return 0;
+
+fail:
+        log_warning_errno(errno, "Failed to read /proc/devices: %m");
+        return -errno;
+}
+
+void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, ManagerState state) {
+        bool is_root;
+        int r;
+
+        assert(c);
+        assert(path);
+
+        if (mask == 0)
+                return;
+
+        /* Some cgroup attributes are not supported on the root cgroup,
+         * hence silently ignore */
+        is_root = isempty(path) || path_equal(path, "/");
+        if (is_root)
+                /* Make sure we don't try to display messages with an empty path. */
+                path = "/";
+
+        /* We generally ignore errors caused by read-only mounted
+         * cgroup trees (assuming we are running in a container then),
+         * and missing cgroups, i.e. EROFS and ENOENT. */
+
+        if ((mask & CGROUP_MASK_CPU) && !is_root) {
+                char buf[MAX(DECIMAL_STR_MAX(unsigned long), DECIMAL_STR_MAX(usec_t)) + 1];
+
+                sprintf(buf, "%lu\n",
+                        IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_cpu_shares != (unsigned long) -1 ? c->startup_cpu_shares :
+                        c->cpu_shares != (unsigned long) -1 ? c->cpu_shares : 1024);
+                r = cg_set_attribute("cpu", path, "cpu.shares", buf);
+                if (r < 0)
+                        log_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to set cpu.shares on %s: %m", path);
+
+                sprintf(buf, USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC);
+                r = cg_set_attribute("cpu", path, "cpu.cfs_period_us", buf);
+                if (r < 0)
+                        log_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to set cpu.cfs_period_us on %s: %m", path);
+
+                if (c->cpu_quota_per_sec_usec != USEC_INFINITY) {
+                        sprintf(buf, USEC_FMT "\n", c->cpu_quota_per_sec_usec * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC);
+                        r = cg_set_attribute("cpu", path, "cpu.cfs_quota_us", buf);
+                } else
+                        r = cg_set_attribute("cpu", path, "cpu.cfs_quota_us", "-1");
+                if (r < 0)
+                        log_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to set cpu.cfs_quota_us on %s: %m", path);
+        }
+
+        if (mask & CGROUP_MASK_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;
+
+                if (!is_root) {
+                        sprintf(buf, "%lu\n", IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && c->startup_blockio_weight != (unsigned long) -1 ? c->startup_blockio_weight :
+                                c->blockio_weight != (unsigned long) -1 ? c->blockio_weight : 1000);
+                        r = cg_set_attribute("blkio", path, "blkio.weight", buf);
+                        if (r < 0)
+                                log_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                               "Failed to set blkio.weight on %s: %m", path);
+
+                        /* 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;
+
+                                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_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                                       "Failed to set blkio.weight_device on %s: %m", path);
+                        }
+                }
+
+                /* 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_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                               "Failed to set %s on %s: %m", a, path);
+                }
+        }
+
+        if ((mask & CGROUP_MASK_MEMORY) && !is_root) {
+                if (c->memory_limit != (uint64_t) -1) {
+                        char buf[DECIMAL_STR_MAX(uint64_t) + 1];
+
+                        sprintf(buf, "%" PRIu64 "\n", c->memory_limit);
+
+                        if (cg_unified() <= 0)
+                                r = cg_set_attribute("memory", path, "memory.limit_in_bytes", buf);
+                        else
+                                r = cg_set_attribute("memory", path, "memory.max", buf);
+
+                } else {
+                        if (cg_unified() <= 0)
+                                r = cg_set_attribute("memory", path, "memory.limit_in_bytes", "-1");
+                        else
+                                r = cg_set_attribute("memory", path, "memory.max", "max");
+                }
+
+                if (r < 0)
+                        log_full_errno(IN_SET(r, -ENOENT, -EROFS) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to set memory.limit_in_bytes/memory.max on %s: %m", path);
+        }
+
+        if ((mask & CGROUP_MASK_DEVICE) && !is_root) {
+                CGroupDeviceAllow *a;
+
+                /* Changing the devices list of a populated cgroup
+                 * might result in EINVAL, hence ignore EINVAL
+                 * here. */
+
+                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_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL) ? LOG_DEBUG : LOG_WARNING, r,
+                                       "Failed to reset devices.list on %s: %m", path);
+
+                if (c->device_policy == CGROUP_CLOSED ||
+                    (c->device_policy == CGROUP_AUTO && c->device_allow)) {
+                        static const char auto_devices[] =
+                                "/dev/null\0" "rwm\0"
+                                "/dev/zero\0" "rwm\0"
+                                "/dev/full\0" "rwm\0"
+                                "/dev/random\0" "rwm\0"
+                                "/dev/urandom\0" "rwm\0"
+                                "/dev/tty\0" "rwm\0"
+                                "/dev/pts/ptmx\0" "rw\0"; /* /dev/pts/ptmx may not be duplicated, but accessed */
+
+                        const char *x, *y;
+
+                        NULSTR_FOREACH_PAIR(x, y, auto_devices)
+                                whitelist_device(path, x, y);
+
+                        whitelist_major(path, "pts", 'c', "rw");
+                        whitelist_major(path, "kdbus", 'c', "rw");
+                        whitelist_major(path, "kdbus/*", 'c', "rw");
+                }
+
+                LIST_FOREACH(device_allow, a, c->device_allow) {
+                        char acc[4];
+                        unsigned k = 0;
+
+                        if (a->r)
+                                acc[k++] = 'r';
+                        if (a->w)
+                                acc[k++] = 'w';
+                        if (a->m)
+                                acc[k++] = 'm';
+
+                        if (k == 0)
+                                continue;
+
+                        acc[k++] = 0;
+
+                        if (startswith(a->path, "/dev/"))
+                                whitelist_device(path, a->path, acc);
+                        else if (startswith(a->path, "block-"))
+                                whitelist_major(path, a->path + 6, 'b', acc);
+                        else if (startswith(a->path, "char-"))
+                                whitelist_major(path, a->path + 5, 'c', acc);
+                        else
+                                log_debug("Ignoring device %s while writing cgroup attribute.", a->path);
+                }
+        }
+}
+#endif // 0
+
+CGroupMask cgroup_context_get_mask(CGroupContext *c) {
+        CGroupMask mask = 0;
+
+        /* Figure out which controllers we need */
+
+        if (c->cpu_accounting ||
+            c->cpu_shares != (unsigned long) -1 ||
+            c->startup_cpu_shares != (unsigned long) -1 ||
+            c->cpu_quota_per_sec_usec != USEC_INFINITY)
+                mask |= CGROUP_MASK_CPUACCT | CGROUP_MASK_CPU;
+
+        if (c->blockio_accounting ||
+            c->blockio_weight != (unsigned long) -1 ||
+            c->startup_blockio_weight != (unsigned long) -1 ||
+            c->blockio_device_weights ||
+            c->blockio_device_bandwidths)
+                mask |= CGROUP_MASK_BLKIO;
+
+        if (c->memory_accounting ||
+            c->memory_limit != (uint64_t) -1)
+                mask |= CGROUP_MASK_MEMORY;
+
+        if (c->device_allow ||
+            c->device_policy != CGROUP_AUTO)
+                mask |= CGROUP_MASK_DEVICE;
+
+        return mask;
+}
+
+/// UNNEEDED by elogind
+#if 0
+CGroupMask unit_get_own_mask(Unit *u) {
+        CGroupContext *c;
+
+        /* Returns the mask of controllers the unit needs for itself */
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
+
+        /* If delegation is turned on, then turn on all cgroups,
+         * unless we are on the legacy hierarchy and the process we
+         * fork into it is known to drop privileges, and hence
+         * shouldn't get access to the controllers.
+         *
+         * Note that on the unified hierarchy it is safe to delegate
+         * controllers to unprivileged services. */
+
+        if (c->delegate) {
+                ExecContext *e;
+
+                e = unit_get_exec_context(u);
+                if (!e ||
+                    exec_context_maintains_privileges(e) ||
+                    cg_unified() > 0)
+                        return _CGROUP_MASK_ALL;
+        }
+
+        return cgroup_context_get_mask(c);
+}
+
+CGroupMask unit_get_members_mask(Unit *u) {
+        assert(u);
+
+        /* Returns the mask of controllers all of the unit's children
+         * require, merged */
+
+        if (u->cgroup_members_mask_valid)
+                return u->cgroup_members_mask;
+
+        u->cgroup_members_mask = 0;
+
+        if (u->type == UNIT_SLICE) {
+                Unit *member;
+                Iterator i;
+
+                SET_FOREACH(member, u->dependencies[UNIT_BEFORE], i) {
+
+                        if (member == u)
+                                continue;
+
+                        if (UNIT_DEREF(member->slice) != u)
+                                continue;
+
+                        u->cgroup_members_mask |=
+                                unit_get_own_mask(member) |
+                                unit_get_members_mask(member);
+                }
+        }
+
+        u->cgroup_members_mask_valid = true;
+        return u->cgroup_members_mask;
+}
+
+CGroupMask unit_get_siblings_mask(Unit *u) {
+        assert(u);
+
+        /* Returns the mask of controllers all of the unit's siblings
+         * require, i.e. the members mask of the unit's parent slice
+         * if there is one. */
+
+        if (UNIT_ISSET(u->slice))
+                return unit_get_members_mask(UNIT_DEREF(u->slice));
+
+        return unit_get_own_mask(u) | unit_get_members_mask(u);
+}
+
+CGroupMask unit_get_subtree_mask(Unit *u) {
+
+        /* Returns the mask of this subtree, meaning of the group
+         * itself and its children. */
+
+        return unit_get_own_mask(u) | unit_get_members_mask(u);
+}
+
+CGroupMask unit_get_target_mask(Unit *u) {
+        CGroupMask mask;
+
+        /* This returns the cgroup mask of all controllers to enable
+         * for a specific cgroup, i.e. everything it needs itself,
+         * plus all that its children need, plus all that its siblings
+         * need. This is primarily useful on the legacy cgroup
+         * hierarchy, where we need to duplicate each cgroup in each
+         * hierarchy that shall be enabled for it. */
+
+        mask = unit_get_own_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
+        mask &= u->manager->cgroup_supported;
+
+        return mask;
+}
+
+CGroupMask unit_get_enable_mask(Unit *u) {
+        CGroupMask mask;
+
+        /* This returns the cgroup mask of all controllers to enable
+         * for the children of a specific cgroup. This is primarily
+         * useful for the unified cgroup hierarchy, where each cgroup
+         * controls which controllers are enabled for its children. */
+
+        mask = unit_get_members_mask(u);
+        mask &= u->manager->cgroup_supported;
+
+        return mask;
+}
+
+/* Recurse from a unit up through its containing slices, propagating
+ * mask bits upward. A unit is also member of itself. */
+void unit_update_cgroup_members_masks(Unit *u) {
+        CGroupMask m;
+        bool more;
+
+        assert(u);
+
+        /* Calculate subtree mask */
+        m = unit_get_subtree_mask(u);
+
+        /* See if anything changed from the previous invocation. If
+         * not, we're done. */
+        if (u->cgroup_subtree_mask_valid && m == u->cgroup_subtree_mask)
+                return;
+
+        more =
+                u->cgroup_subtree_mask_valid &&
+                ((m & ~u->cgroup_subtree_mask) != 0) &&
+                ((~m & u->cgroup_subtree_mask) == 0);
+
+        u->cgroup_subtree_mask = m;
+        u->cgroup_subtree_mask_valid = true;
+
+        if (UNIT_ISSET(u->slice)) {
+                Unit *s = UNIT_DEREF(u->slice);
+
+                if (more)
+                        /* There's more set now than before. We
+                         * propagate the new mask to the parent's mask
+                         * (not caring if it actually was valid or
+                         * not). */
+
+                        s->cgroup_members_mask |= m;
+
+                else
+                        /* There's less set now than before (or we
+                         * don't know), we need to recalculate
+                         * everything, so let's invalidate the
+                         * parent's members mask */
+
+                        s->cgroup_members_mask_valid = false;
+
+                /* And now make sure that this change also hits our
+                 * grandparents */
+                unit_update_cgroup_members_masks(s);
+        }
+}
+
+static const char *migrate_callback(CGroupMask mask, void *userdata) {
+        Unit *u = userdata;
+
+        assert(mask != 0);
+        assert(u);
+
+        while (u) {
+                if (u->cgroup_path &&
+                    u->cgroup_realized &&
+                    (u->cgroup_realized_mask & mask) == mask)
+                        return u->cgroup_path;
+
+                u = UNIT_DEREF(u->slice);
+        }
+
+        return NULL;
+}
+
+char *unit_default_cgroup_path(Unit *u) {
+        _cleanup_free_ char *escaped = NULL, *slice = NULL;
+        int r;
+
+        assert(u);
+
+        if (unit_has_name(u, SPECIAL_ROOT_SLICE))
+                return strdup(u->manager->cgroup_root);
+
+        if (UNIT_ISSET(u->slice) && !unit_has_name(UNIT_DEREF(u->slice), SPECIAL_ROOT_SLICE)) {
+                r = cg_slice_to_path(UNIT_DEREF(u->slice)->id, &slice);
+                if (r < 0)
+                        return NULL;
+        }
+
+        escaped = cg_escape(u->id);
+        if (!escaped)
+                return NULL;
+
+        if (slice)
+                return strjoin(u->manager->cgroup_root, "/", slice, "/", escaped, NULL);
+        else
+                return strjoin(u->manager->cgroup_root, "/", escaped, NULL);
+}
+
+int unit_set_cgroup_path(Unit *u, const char *path) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(u);
+
+        if (path) {
+                p = strdup(path);
+                if (!p)
+                        return -ENOMEM;
+        } else
+                p = NULL;
+
+        if (streq_ptr(u->cgroup_path, p))
+                return 0;
+
+        if (p) {
+                r = hashmap_put(u->manager->cgroup_unit, p, u);
+                if (r < 0)
+                        return r;
+        }
+
+        unit_release_cgroup(u);
+
+        u->cgroup_path = p;
+        p = NULL;
+
+        return 1;
+}
+
+int unit_watch_cgroup(Unit *u) {
+        _cleanup_free_ char *populated = NULL;
+        int r;
+
+        assert(u);
+
+        if (!u->cgroup_path)
+                return 0;
+
+        if (u->cgroup_inotify_wd >= 0)
+                return 0;
+
+        /* Only applies to the unified hierarchy */
+        r = cg_unified();
+        if (r < 0)
+                return log_unit_error_errno(u, r, "Failed detect wether the unified hierarchy is used: %m");
+        if (r == 0)
+                return 0;
+
+        /* Don't watch the root slice, it's pointless. */
+        if (unit_has_name(u, SPECIAL_ROOT_SLICE))
+                return 0;
+
+        r = hashmap_ensure_allocated(&u->manager->cgroup_inotify_wd_unit, &trivial_hash_ops);
+        if (r < 0)
+                return log_oom();
+
+        r = cg_get_path(ELOGIND_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.populated", &populated);
+        if (r < 0)
+                return log_oom();
+
+        u->cgroup_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, populated, IN_MODIFY);
+        if (u->cgroup_inotify_wd < 0) {
+
+                if (errno == ENOENT) /* If the directory is already
+                                      * gone we don't need to track
+                                      * it, so this is not an error */
+                        return 0;
+
+                return log_unit_error_errno(u, errno, "Failed to add inotify watch descriptor for control group %s: %m", u->cgroup_path);
+        }
+
+        r = hashmap_put(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd), u);
+        if (r < 0)
+                return log_unit_error_errno(u, r, "Failed to add inotify watch descriptor to hash map: %m");
+
+        return 0;
+}
+
+static int unit_create_cgroup(
+                Unit *u,
+                CGroupMask target_mask,
+                CGroupMask enable_mask) {
+
+        CGroupContext *c;
+        int r;
+
+        assert(u);
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
+
+        if (!u->cgroup_path) {
+                _cleanup_free_ char *path = NULL;
+
+                path = unit_default_cgroup_path(u);
+                if (!path)
+                        return log_oom();
+
+                r = unit_set_cgroup_path(u, path);
+                if (r == -EEXIST)
+                        return log_unit_error_errno(u, r, "Control group %s exists already.", path);
+                if (r < 0)
+                        return log_unit_error_errno(u, r, "Failed to set unit's control group path to %s: %m", path);
+        }
+
+        /* First, create our own group */
+        r = cg_create_everywhere(u->manager->cgroup_supported, target_mask, u->cgroup_path);
+        if (r < 0)
+                return log_unit_error_errno(u, r, "Failed to create cgroup %s: %m", u->cgroup_path);
+
+        /* Start watching it */
+        (void) unit_watch_cgroup(u);
+
+        /* Enable all controllers we need */
+        r = cg_enable_everywhere(u->manager->cgroup_supported, enable_mask, u->cgroup_path);
+        if (r < 0)
+                log_unit_warning_errno(u, r, "Failed to enable controllers on cgroup %s, ignoring: %m", u->cgroup_path);
+
+        /* Keep track that this is now realized */
+        u->cgroup_realized = true;
+        u->cgroup_realized_mask = target_mask;
+
+        if (u->type != UNIT_SLICE && !c->delegate) {
+
+                /* Then, possibly move things over, but not if
+                 * subgroups may contain processes, which is the case
+                 * for slice and delegation units. */
+                r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, u->cgroup_path, migrate_callback, u);
+                if (r < 0)
+                        log_unit_warning_errno(u, r, "Failed to migrate cgroup from to %s, ignoring: %m", u->cgroup_path);
+        }
+
+        return 0;
+}
+
+int unit_attach_pids_to_cgroup(Unit *u) {
+        int r;
+        assert(u);
+
+        r = unit_realize_cgroup(u);
+        if (r < 0)
+                return r;
+
+        r = cg_attach_many_everywhere(u->manager->cgroup_supported, u->cgroup_path, u->pids, migrate_callback, u);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static bool unit_has_mask_realized(Unit *u, CGroupMask target_mask) {
+        assert(u);
+
+        return u->cgroup_realized && u->cgroup_realized_mask == target_mask;
+}
+
+/* Check if necessary controllers and attributes for a unit are in place.
+ *
+ * If so, do nothing.
+ * If not, create paths, move processes over, and set attributes.
+ *
+ * Returns 0 on success and < 0 on failure. */
+static int unit_realize_cgroup_now(Unit *u, ManagerState state) {
+        CGroupMask target_mask, enable_mask;
+        int r;
+
+        assert(u);
+
+        if (u->in_cgroup_queue) {
+                LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
+                u->in_cgroup_queue = false;
+        }
+
+        target_mask = unit_get_target_mask(u);
+        if (unit_has_mask_realized(u, target_mask))
+                return 0;
+
+        /* First, realize parents */
+        if (UNIT_ISSET(u->slice)) {
+                r = unit_realize_cgroup_now(UNIT_DEREF(u->slice), state);
+                if (r < 0)
+                        return r;
+        }
+
+        /* And then do the real work */
+        enable_mask = unit_get_enable_mask(u);
+        r = unit_create_cgroup(u, target_mask, enable_mask);
+        if (r < 0)
+                return r;
+
+        /* Finally, apply the necessary attributes. */
+        cgroup_context_apply(unit_get_cgroup_context(u), target_mask, u->cgroup_path, state);
+
+        return 0;
+}
+
+static void unit_add_to_cgroup_queue(Unit *u) {
+
+        if (u->in_cgroup_queue)
+                return;
+
+        LIST_PREPEND(cgroup_queue, u->manager->cgroup_queue, u);
+        u->in_cgroup_queue = true;
+}
+
+unsigned manager_dispatch_cgroup_queue(Manager *m) {
+        ManagerState state;
+        unsigned n = 0;
+        Unit *i;
+        int r;
+
+        state = manager_state(m);
+
+        while ((i = m->cgroup_queue)) {
+                assert(i->in_cgroup_queue);
+
+                r = unit_realize_cgroup_now(i, state);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to realize cgroups for queued unit %s, ignoring: %m", i->id);
+
+                n++;
+        }
+
+        return n;
+}
+
+static void unit_queue_siblings(Unit *u) {
+        Unit *slice;
+
+        /* 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.) */
+
+        while ((slice = UNIT_DEREF(u->slice))) {
+                Iterator i;
+                Unit *m;
+
+                SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
+                        if (m == u)
+                                continue;
+
+                        /* Skip units that have a dependency on the slice
+                         * but aren't actually in it. */
+                        if (UNIT_DEREF(m->slice) != slice)
+                                continue;
+
+                        /* No point in doing cgroup application for units
+                         * without active processes. */
+                        if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m)))
+                                continue;
+
+                        /* If the unit doesn't need any new controllers
+                         * and has current ones realized, it doesn't need
+                         * any changes. */
+                        if (unit_has_mask_realized(m, unit_get_target_mask(m)))
+                                continue;
+
+                        unit_add_to_cgroup_queue(m);
+                }
+
+                u = slice;
+        }
+}
+
+int unit_realize_cgroup(Unit *u) {
+        assert(u);
+
+        if (!UNIT_HAS_CGROUP_CONTEXT(u))
+                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 cgroups, 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 (and apply the values) */
+        return unit_realize_cgroup_now(u, manager_state(u->manager));
+}
+
+void unit_release_cgroup(Unit *u) {
+        assert(u);
+
+        /* Forgets all cgroup details for this cgroup */
+
+        if (u->cgroup_path) {
+                (void) hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
+                u->cgroup_path = mfree(u->cgroup_path);
+        }
+
+        if (u->cgroup_inotify_wd >= 0) {
+                if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_inotify_wd) < 0)
+                        log_unit_debug_errno(u, errno, "Failed to remove cgroup inotify watch %i for %s, ignoring", u->cgroup_inotify_wd, u->id);
+
+                (void) hashmap_remove(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd));
+                u->cgroup_inotify_wd = -1;
+        }
+}
+
+void unit_prune_cgroup(Unit *u) {
+        int r;
+        bool is_root_slice;
+
+        assert(u);
+
+        /* Removes the cgroup, if empty and possible, and stops watching it. */
+
+        if (!u->cgroup_path)
+                return;
+
+        is_root_slice = unit_has_name(u, SPECIAL_ROOT_SLICE);
+
+        r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !is_root_slice);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to destroy cgroup %s, ignoring: %m", u->cgroup_path);
+                return;
+        }
+
+        if (is_root_slice)
+                return;
+
+        unit_release_cgroup(u);
+
+        u->cgroup_realized = false;
+        u->cgroup_realized_mask = 0;
+}
+
+int unit_search_main_pid(Unit *u, pid_t *ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+        pid_t pid = 0, npid, mypid;
+        int r;
+
+        assert(u);
+        assert(ret);
+
+        if (!u->cgroup_path)
+                return -ENXIO;
+
+        r = cg_enumerate_processes(ELOGIND_CGROUP_CONTROLLER, u->cgroup_path, &f);
+        if (r < 0)
+                return r;
+
+        mypid = getpid();
+        while (cg_read_pid(f, &npid) > 0)  {
+                pid_t ppid;
+
+                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. */
+
+                        return -ENODATA;
+
+                pid = npid;
+        }
+
+        *ret = pid;
+        return 0;
+}
+
+static int unit_watch_pids_in_path(Unit *u, const char *path) {
+        _cleanup_closedir_ DIR *d = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int ret = 0, r;
+
+        assert(u);
+        assert(path);
+
+        r = cg_enumerate_processes(ELOGIND_CGROUP_CONTROLLER, path, &f);
+        if (r < 0)
+                ret = r;
+        else {
+                pid_t pid;
+
+                while ((r = cg_read_pid(f, &pid)) > 0) {
+                        r = unit_watch_pid(u, pid);
+                        if (r < 0 && ret >= 0)
+                                ret = r;
+                }
+
+                if (r < 0 && ret >= 0)
+                        ret = r;
+        }
+
+        r = cg_enumerate_subgroups(ELOGIND_CGROUP_CONTROLLER, path, &d);
+        if (r < 0) {
+                if (ret >= 0)
+                        ret = r;
+        } else {
+                char *fn;
+
+                while ((r = cg_read_subgroup(d, &fn)) > 0) {
+                        _cleanup_free_ char *p = NULL;
+
+                        p = strjoin(path, "/", fn, NULL);
+                        free(fn);
+
+                        if (!p)
+                                return -ENOMEM;
+
+                        r = unit_watch_pids_in_path(u, p);
+                        if (r < 0 && ret >= 0)
+                                ret = r;
+                }
+
+                if (r < 0 && ret >= 0)
+                        ret = r;
+        }
+
+        return ret;
+}
+
+int unit_watch_all_pids(Unit *u) {
+        assert(u);
+
+        /* Adds all PIDs from our cgroup to the set of PIDs we
+         * watch. This is a fallback logic for cases where we do not
+         * get reliable cgroup empty notifications: we try to use
+         * SIGCHLD as replacement. */
+
+        if (!u->cgroup_path)
+                return -ENOENT;
+
+        if (cg_unified() > 0) /* On unified we can use proper notifications */
+                return 0;
+
+        return unit_watch_pids_in_path(u, u->cgroup_path);
+}
+
+int unit_notify_cgroup_empty(Unit *u) {
+        int r;
+
+        assert(u);
+
+        if (!u->cgroup_path)
+                return 0;
+
+        r = cg_is_empty_recursive(ELOGIND_CGROUP_CONTROLLER, u->cgroup_path);
+        if (r <= 0)
+                return r;
+
+        unit_add_to_gc_queue(u);
+
+        if (UNIT_VTABLE(u)->notify_cgroup_empty)
+                UNIT_VTABLE(u)->notify_cgroup_empty(u);
+
+        return 0;
+}
+
+static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Manager *m = userdata;
+
+        assert(s);
+        assert(fd >= 0);
+        assert(m);
+
+        for (;;) {
+                union inotify_event_buffer buffer;
+                struct inotify_event *e;
+                ssize_t l;
+
+                l = read(fd, &buffer, sizeof(buffer));
+                if (l < 0) {
+                        if (errno == EINTR || errno == EAGAIN)
+                                return 0;
+
+                        return log_error_errno(errno, "Failed to read control group inotify events: %m");
+                }
+
+                FOREACH_INOTIFY_EVENT(e, buffer, l) {
+                        Unit *u;
+
+                        if (e->wd < 0)
+                                /* Queue overflow has no watch descriptor */
+                                continue;
+
+                        if (e->mask & IN_IGNORED)
+                                /* The watch was just removed */
+                                continue;
+
+                        u = hashmap_get(m->cgroup_inotify_wd_unit, INT_TO_PTR(e->wd));
+                        if (!u) /* Not that inotify might deliver
+                                 * events for a watch even after it
+                                 * was removed, because it was queued
+                                 * before the removal. Let's ignore
+                                 * this here safely. */
+                                continue;
+
+                        (void) unit_notify_cgroup_empty(u);
+                }
+        }
+}
+#endif // 0
+
+int manager_setup_cgroup(Manager *m) {
+        _cleanup_free_ char *path = NULL;
+        CGroupController c;
+        int r, unified;
+        char *e;
+
+        assert(m);
+
+        /* 1. Determine hierarchy */
+        m->cgroup_root = mfree(m->cgroup_root);
+        r = cg_pid_get_path(ELOGIND_CGROUP_CONTROLLER, 0, &m->cgroup_root);
+        if (r < 0)
+                return log_error_errno(r, "Cannot determine cgroup we are running in: %m");
+
+        /* Chop off the init scope, if we are already located in it */
+        e = endswith(m->cgroup_root, "/" SPECIAL_INIT_SCOPE);
+
+        /* LEGACY: Also chop off the system slice if we are in
+         * it. This is to support live upgrades from older systemd
+         * versions where PID 1 was moved there. Also see
+         * cg_get_root_path(). */
+        if (!e) {
+                e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
+                if (!e)
+                        e = endswith(m->cgroup_root, "/system"); /* even more legacy */
+        }
+        if (e)
+                *e = 0;
+
+        /* 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. */
+        while ((e = endswith(m->cgroup_root, "/")))
+                *e = 0;
+
+        /* 2. Show data */
+        r = cg_get_path(ELOGIND_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
+        if (r < 0)
+                return log_error_errno(r, "Cannot find cgroup mount point: %m");
+
+        unified = cg_unified();
+        if (unified < 0)
+                return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m");
+        if (unified > 0)
+                log_debug("Unified cgroup hierarchy is located at %s.", path);
+        else
+                log_debug("Using cgroup controller " ELOGIND_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
+
+        if (!m->test_run) {
+                const char *scope_path;
+
+                /* 3. Install agent */
+                if (unified) {
+
+                        /* In the unified hierarchy we can can get
+                         * cgroup empty notifications via inotify. */
+/// elogind does not support the unified hierarchy, yet.
+#if 0
+                        m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source);
+                        safe_close(m->cgroup_inotify_fd);
+
+                        m->cgroup_inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
+                        if (m->cgroup_inotify_fd < 0)
+                                return log_error_errno(errno, "Failed to create control group inotify object: %m");
+
+                        r = sd_event_add_io(m->event, &m->cgroup_inotify_event_source, m->cgroup_inotify_fd, EPOLLIN, on_cgroup_inotify_event, m);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to watch control group inotify object: %m");
+
+                        r = sd_event_source_set_priority(m->cgroup_inotify_event_source, SD_EVENT_PRIORITY_IDLE - 5);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to set priority of inotify event source: %m");
+
+                        (void) sd_event_source_set_description(m->cgroup_inotify_event_source, "cgroup-inotify");
+
+#else
+                        return log_error_errno(EOPNOTSUPP, "Unified cgroup hierarchy not supported: %m");
+#endif // elogind
+                } else if (m->running_as == MANAGER_SYSTEM) {
+                        /* On the legacy hierarchy we only get
+                         * notifications via cgroup agents. (Which
+                         * isn't really reliable, since it does not
+                         * generate events when control groups with
+                         * children run empty. */
+
+                        r = cg_install_release_agent(ELOGIND_CGROUP_CONTROLLER, ELOGIND_CGROUP_AGENT_PATH);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to install release agent, ignoring: %m");
+                        else if (r > 0)
+                                log_debug("Installed release agent.");
+                        else if (r == 0)
+                                log_debug("Release agent already installed.");
+                }
+
+                /* 4. Make sure we are in the special "init.scope" unit in the root slice. */
+                scope_path = strjoina(m->cgroup_root, "/" SPECIAL_INIT_SCOPE);
+                r = cg_create_and_attach(ELOGIND_CGROUP_CONTROLLER, scope_path, 0);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create %s control group: %m", scope_path);
+
+                /* also, move all other userspace processes remaining
+                 * in the root cgroup into that scope. */
+                r = cg_migrate(ELOGIND_CGROUP_CONTROLLER, m->cgroup_root, ELOGIND_CGROUP_CONTROLLER, scope_path, false);
+                if (r < 0)
+                        log_warning_errno(r, "Couldn't move remaining userspace processes, ignoring: %m");
+
+                /* 5. And pin it, so that it cannot be unmounted */
+                safe_close(m->pin_cgroupfs_fd);
+                m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
+                if (m->pin_cgroupfs_fd < 0)
+                        return log_error_errno(errno, "Failed to open pin file: %m");
+
+                /* 6.  Always enable hierarchical support if it exists... */
+                if (!unified)
+                        (void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
+        }
+
+        /* 7. Figure out which controllers are supported */
+        r = cg_mask_supported(&m->cgroup_supported);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine supported controllers: %m");
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++)
+                log_debug("Controller '%s' supported: %s", cgroup_controller_to_string(c), yes_no(m->cgroup_supported & c));
+
+        return 0;
+}
+
+void manager_shutdown_cgroup(Manager *m, bool delete) {
+        assert(m);
+
+        /* We can't really delete the group, since we are in it. But
+         * let's trim it. */
+        if (delete && m->cgroup_root)
+                (void) cg_trim(ELOGIND_CGROUP_CONTROLLER, m->cgroup_root, false);
+
+/// elogind does not support the unified hierarchy, yet.
+#if 0
+        m->cgroup_inotify_wd_unit = hashmap_free(m->cgroup_inotify_wd_unit);
+
+        m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source);
+        m->cgroup_inotify_fd = safe_close(m->cgroup_inotify_fd);
+#endif // 0
+
+        m->pin_cgroupfs_fd = safe_close(m->pin_cgroupfs_fd);
+
+        m->cgroup_root = mfree(m->cgroup_root);
+}
+
+/// UNNEEDED by elogind
+#if 0
+Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
+        char *p;
+        Unit *u;
+
+        assert(m);
+        assert(cgroup);
+
+        u = hashmap_get(m->cgroup_unit, cgroup);
+        if (u)
+                return u;
+
+        p = strdupa(cgroup);
+        for (;;) {
+                char *e;
+
+                e = strrchr(p, '/');
+                if (!e || e == p)
+                        return hashmap_get(m->cgroup_unit, SPECIAL_ROOT_SLICE);
+
+                *e = 0;
+
+                u = hashmap_get(m->cgroup_unit, p);
+                if (u)
+                        return u;
+        }
+}
+
+Unit *manager_get_unit_by_pid_cgroup(Manager *m, pid_t pid) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(m);
+
+        if (pid <= 0)
+                return NULL;
+
+        r = cg_pid_get_path(ELOGIND_CGROUP_CONTROLLER, pid, &cgroup);
+        if (r < 0)
+                return NULL;
+
+        return manager_get_unit_by_cgroup(m, cgroup);
+}
+
+Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
+        Unit *u;
+
+        assert(m);
+
+        if (pid <= 0)
+                return NULL;
+
+        if (pid == 1)
+                return hashmap_get(m->units, SPECIAL_INIT_SCOPE);
+
+        u = hashmap_get(m->watch_pids1, PID_TO_PTR(pid));
+        if (u)
+                return u;
+
+        u = hashmap_get(m->watch_pids2, PID_TO_PTR(pid));
+        if (u)
+                return u;
+
+        return manager_get_unit_by_pid_cgroup(m, pid);
+}
+
+int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
+        Unit *u;
+
+        assert(m);
+        assert(cgroup);
+
+        u = manager_get_unit_by_cgroup(m, cgroup);
+        if (!u)
+                return 0;
+
+        return unit_notify_cgroup_empty(u);
+}
+
+int unit_get_memory_current(Unit *u, uint64_t *ret) {
+        _cleanup_free_ char *v = NULL;
+        int r;
+
+        assert(u);
+        assert(ret);
+
+        if (!u->cgroup_path)
+                return -ENODATA;
+
+        if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0)
+                return -ENODATA;
+
+        if (cg_unified() <= 0)
+                r = cg_get_attribute("memory", u->cgroup_path, "memory.usage_in_bytes", &v);
+        else
+                r = cg_get_attribute("memory", u->cgroup_path, "memory.current", &v);
+        if (r == -ENOENT)
+                return -ENODATA;
+        if (r < 0)
+                return r;
+
+        return safe_atou64(v, ret);
+}
+
+static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) {
+        _cleanup_free_ char *v = NULL;
+        uint64_t ns;
+        int r;
+
+        assert(u);
+        assert(ret);
+
+        if (!u->cgroup_path)
+                return -ENODATA;
+
+        if ((u->cgroup_realized_mask & CGROUP_MASK_CPUACCT) == 0)
+                return -ENODATA;
+
+        r = cg_get_attribute("cpuacct", u->cgroup_path, "cpuacct.usage", &v);
+        if (r == -ENOENT)
+                return -ENODATA;
+        if (r < 0)
+                return r;
+
+        r = safe_atou64(v, &ns);
+        if (r < 0)
+                return r;
+
+        *ret = ns;
+        return 0;
+}
+
+int unit_get_cpu_usage(Unit *u, nsec_t *ret) {
+        nsec_t ns;
+        int r;
+
+        r = unit_get_cpu_usage_raw(u, &ns);
+        if (r < 0)
+                return r;
+
+        if (ns > u->cpuacct_usage_base)
+                ns -= u->cpuacct_usage_base;
+        else
+                ns = 0;
+
+        *ret = ns;
+        return 0;
+}
+
+int unit_reset_cpu_usage(Unit *u) {
+        nsec_t ns;
+        int r;
+
+        assert(u);
+
+        r = unit_get_cpu_usage_raw(u, &ns);
+        if (r < 0) {
+                u->cpuacct_usage_base = 0;
+                return r;
+        }
+
+        u->cpuacct_usage_base = ns;
+        return 0;
+}
+
+bool unit_cgroup_delegate(Unit *u) {
+        CGroupContext *c;
+
+        assert(u);
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return false;
+
+        return c->delegate;
+}
+#endif // 0
+
+static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
+        [CGROUP_AUTO] = "auto",
+        [CGROUP_CLOSED] = "closed",
+        [CGROUP_STRICT] = "strict",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
new file mode 100644 (file)
index 0000000..767eea2
--- /dev/null
@@ -0,0 +1,150 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+
+#include "list.h"
+#include "time-util.h"
+#include "logind.h"
+
+typedef struct CGroupContext CGroupContext;
+typedef struct CGroupDeviceAllow CGroupDeviceAllow;
+typedef struct CGroupBlockIODeviceWeight CGroupBlockIODeviceWeight;
+typedef struct CGroupBlockIODeviceBandwidth CGroupBlockIODeviceBandwidth;
+
+typedef enum CGroupDevicePolicy {
+
+        /* When devices listed, will allow those, plus built-in ones,
+        if none are listed will allow everything. */
+        CGROUP_AUTO,
+
+        /* Everything forbidden, except built-in ones and listed ones. */
+        CGROUP_CLOSED,
+
+        /* Everythings forbidden, except for the listed devices */
+        CGROUP_STRICT,
+
+        _CGROUP_DEVICE_POLICY_MAX,
+        _CGROUP_DEVICE_POLICY_INVALID = -1
+} CGroupDevicePolicy;
+
+struct CGroupDeviceAllow {
+        LIST_FIELDS(CGroupDeviceAllow, device_allow);
+        char *path;
+        bool r:1;
+        bool w:1;
+        bool m:1;
+};
+
+struct CGroupBlockIODeviceWeight {
+        LIST_FIELDS(CGroupBlockIODeviceWeight, device_weights);
+        char *path;
+        unsigned long weight;
+};
+
+struct CGroupBlockIODeviceBandwidth {
+        LIST_FIELDS(CGroupBlockIODeviceBandwidth, device_bandwidths);
+        char *path;
+        uint64_t bandwidth;
+        bool read;
+};
+
+struct CGroupContext {
+        bool cpu_accounting;
+        bool blockio_accounting;
+        bool memory_accounting;
+
+        unsigned long cpu_shares;
+        unsigned long startup_cpu_shares;
+        usec_t cpu_quota_per_sec_usec;
+
+        unsigned long blockio_weight;
+        unsigned long startup_blockio_weight;
+        LIST_HEAD(CGroupBlockIODeviceWeight, blockio_device_weights);
+        LIST_HEAD(CGroupBlockIODeviceBandwidth, blockio_device_bandwidths);
+
+        uint64_t memory_limit;
+
+        CGroupDevicePolicy device_policy;
+        LIST_HEAD(CGroupDeviceAllow, device_allow);
+
+        bool delegate;
+};
+
+// #include "unit.h"
+#include "cgroup-util.h"
+
+void cgroup_context_init(CGroupContext *c);
+void cgroup_context_done(CGroupContext *c);
+// UNNEEDED void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix);
+// UNNEEDED void cgroup_context_apply(CGroupContext *c, CGroupMask mask, const char *path, ManagerState state);
+
+CGroupMask cgroup_context_get_mask(CGroupContext *c);
+
+void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a);
+void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w);
+void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b);
+
+// UNNEEDED CGroupMask unit_get_own_mask(Unit *u);
+// UNNEEDED CGroupMask unit_get_siblings_mask(Unit *u);
+// UNNEEDED CGroupMask unit_get_members_mask(Unit *u);
+// UNNEEDED CGroupMask unit_get_subtree_mask(Unit *u);
+
+// UNNEEDED vCGroupMask unit_get_target_mask(Unit *u);
+// UNNEEDED CGroupMask unit_get_enable_mask(Unit *u);
+
+// UNNEEDED void unit_update_cgroup_members_masks(Unit *u);
+
+// UNNEEDED har *unit_default_cgroup_path(Unit *u);
+// UNNEEDED int unit_set_cgroup_path(Unit *u, const char *path);
+
+// UNNEEDED int unit_realize_cgroup(Unit *u);
+// UNNEEDED void unit_release_cgroup(Unit *u);
+// UNNEEDED void unit_prune_cgroup(Unit *u);
+// UNNEEDED int unit_watch_cgroup(Unit *u);
+
+// UNNEEDED int unit_attach_pids_to_cgroup(Unit *u);
+
+int manager_setup_cgroup(Manager *m);
+void manager_shutdown_cgroup(Manager *m, bool delete);
+
+// UNNEEDED unsigned manager_dispatch_cgroup_queue(Manager *m);
+
+// UNNEEDED Unit *manager_get_unit_by_cgroup(Manager *m, const char *cgroup);
+// UNNEEDED Unit *manager_get_unit_by_pid_cgroup(Manager *m, pid_t pid);
+// UNNEEDED Unit* manager_get_unit_by_pid(Manager *m, pid_t pid);
+
+// UNNEEDED int unit_search_main_pid(Unit *u, pid_t *ret);
+// UNNEEDED int unit_watch_all_pids(Unit *u);
+
+// UNNEEDED int unit_get_memory_current(Unit *u, uint64_t *ret);
+// UNNEEDED int unit_get_cpu_usage(Unit *u, nsec_t *ret);
+// UNNEEDED int unit_reset_cpu_usage(Unit *u);
+
+// UNNEEDED bool unit_cgroup_delegate(Unit *u);
+
+// UNNEEDED int unit_notify_cgroup_empty(Unit *u);
+// UNNEEDED int manager_notify_cgroup_empty(Manager *m, const char *group);
+
+const char* cgroup_device_policy_to_string(CGroupDevicePolicy i) _const_;
+CGroupDevicePolicy cgroup_device_policy_from_string(const char *s) _pure_;