1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2013 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 #include "path-util.h"
26 #include "cgroup-util.h"
29 void cgroup_context_init(CGroupContext *c) {
32 /* Initialize everything to the kernel defaults, assuming the
33 * structure is preinitialized to 0 */
36 c->memory_limit = (uint64_t) -1;
37 c->blockio_weight = 1000;
40 void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) {
44 LIST_REMOVE(device_allow, c->device_allow, a);
49 void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) {
53 LIST_REMOVE(device_weights, c->blockio_device_weights, w);
58 void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b) {
62 LIST_REMOVE(device_bandwidths, c->blockio_device_bandwidths, b);
67 void cgroup_context_done(CGroupContext *c) {
70 while (c->blockio_device_weights)
71 cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights);
73 while (c->blockio_device_bandwidths)
74 cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths);
76 while (c->device_allow)
77 cgroup_context_free_device_allow(c, c->device_allow);
80 void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
81 CGroupBlockIODeviceBandwidth *b;
82 CGroupBlockIODeviceWeight *w;
88 prefix = strempty(prefix);
91 "%sCPUAccounting=%s\n"
92 "%sBlockIOAccounting=%s\n"
93 "%sMemoryAccounting=%s\n"
95 "%sBlockIOWeight=%lu\n"
96 "%sMemoryLimit=%" PRIu64 "\n"
97 "%sDevicePolicy=%s\n",
98 prefix, yes_no(c->cpu_accounting),
99 prefix, yes_no(c->blockio_accounting),
100 prefix, yes_no(c->memory_accounting),
101 prefix, c->cpu_shares,
102 prefix, c->blockio_weight,
103 prefix, c->memory_limit,
104 prefix, cgroup_device_policy_to_string(c->device_policy));
106 LIST_FOREACH(device_allow, a, c->device_allow)
108 "%sDeviceAllow=%s %s%s%s\n",
111 a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : "");
113 LIST_FOREACH(device_weights, w, c->blockio_device_weights)
115 "%sBlockIODeviceWeight=%s %lu",
120 LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
121 char buf[FORMAT_BYTES_MAX];
126 b->read ? "BlockIOReadBandwidth" : "BlockIOWriteBandwidth",
128 format_bytes(buf, sizeof(buf), b->bandwidth));
132 static int lookup_blkio_device(const char *p, dev_t *dev) {
141 log_warning("Couldn't stat device %s: %m", p);
145 if (S_ISBLK(st.st_mode))
147 else if (major(st.st_dev) != 0) {
148 /* If this is not a device node then find the block
149 * device this file is stored on */
152 /* If this is a partition, try to get the originating
154 block_get_whole_disk(*dev, dev);
156 log_warning("%s is not a block device and file system block device cannot be determined or is not local.", p);
163 static int whitelist_device(const char *path, const char *node, const char *acc) {
164 char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4];
171 if (stat(node, &st) < 0) {
172 log_warning("Couldn't stat device %s", node);
176 if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
177 log_warning("%s is not a device.", node);
183 S_ISCHR(st.st_mode) ? 'c' : 'b',
184 major(st.st_rdev), minor(st.st_rdev),
187 r = cg_set_attribute("devices", path, "devices.allow", buf);
189 log_warning("Failed to set devices.allow on %s: %s", path, strerror(-r));
194 void cgroup_context_apply(CGroupContext *c, CGroupControllerMask mask, const char *path) {
203 if (mask & CGROUP_CPU) {
204 char buf[DECIMAL_STR_MAX(unsigned long) + 1];
206 sprintf(buf, "%lu\n", c->cpu_shares);
207 r = cg_set_attribute("cpu", path, "cpu.shares", buf);
209 log_warning("Failed to set cpu.shares on %s: %s", path, strerror(-r));
212 if (mask & CGROUP_BLKIO) {
213 char buf[MAX3(DECIMAL_STR_MAX(unsigned long)+1,
214 DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(unsigned long)*1,
215 DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1)];
216 CGroupBlockIODeviceWeight *w;
217 CGroupBlockIODeviceBandwidth *b;
219 sprintf(buf, "%lu\n", c->blockio_weight);
220 r = cg_set_attribute("blkio", path, "blkio.weight", buf);
222 log_warning("Failed to set blkio.weight on %s: %s", path, strerror(-r));
224 /* FIXME: no way to reset this list */
225 LIST_FOREACH(device_weights, w, c->blockio_device_weights) {
228 r = lookup_blkio_device(w->path, &dev);
232 sprintf(buf, "%u:%u %lu", major(dev), minor(dev), w->weight);
233 r = cg_set_attribute("blkio", path, "blkio.weight_device", buf);
235 log_error("Failed to set blkio.weight_device on %s: %s", path, strerror(-r));
238 /* FIXME: no way to reset this list */
239 LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
243 r = lookup_blkio_device(b->path, &dev);
247 a = b->read ? "blkio.throttle.read_bps_device" : "blkio.throttle.write_bps_device";
249 sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), b->bandwidth);
250 r = cg_set_attribute("blkio", path, a, buf);
252 log_error("Failed to set %s on %s: %s", a, path, strerror(-r));
256 if (mask & CGROUP_MEMORY) {
257 if (c->memory_limit != (uint64_t) -1) {
258 char buf[DECIMAL_STR_MAX(uint64_t) + 1];
260 sprintf(buf, "%" PRIu64 "\n", c->memory_limit);
261 r = cg_set_attribute("memory", path, "memory.limit_in_bytes", buf);
263 r = cg_set_attribute("memory", path, "memory.limit_in_bytes", "-1");
266 log_error("Failed to set memory.limit_in_bytes on %s: %s", path, strerror(-r));
269 if (mask & CGROUP_DEVICE) {
270 CGroupDeviceAllow *a;
272 if (c->device_allow || c->device_policy != CGROUP_AUTO)
273 r = cg_set_attribute("devices", path, "devices.deny", "a");
275 r = cg_set_attribute("devices", path, "devices.allow", "a");
277 log_error("Failed to reset devices.list on %s: %s", path, strerror(-r));
279 if (c->device_policy == CGROUP_CLOSED ||
280 (c->device_policy == CGROUP_AUTO && c->device_allow)) {
281 static const char auto_devices[] =
285 "/dev/random\0" "rw\0"
286 "/dev/urandom\0" "rw\0";
290 NULSTR_FOREACH_PAIR(x, y, auto_devices)
291 whitelist_device(path, x, y);
294 LIST_FOREACH(device_allow, a, c->device_allow) {
309 whitelist_device(path, a->path, acc);
314 CGroupControllerMask cgroup_context_get_mask(CGroupContext *c) {
315 CGroupControllerMask mask = 0;
317 /* Figure out which controllers we need */
319 if (c->cpu_accounting || c->cpu_shares != 1024)
320 mask |= CGROUP_CPUACCT | CGROUP_CPU;
322 if (c->blockio_accounting ||
323 c->blockio_weight != 1000 ||
324 c->blockio_device_weights ||
325 c->blockio_device_bandwidths)
326 mask |= CGROUP_BLKIO;
328 if (c->memory_accounting ||
329 c->memory_limit != (uint64_t) -1)
330 mask |= CGROUP_MEMORY;
332 if (c->device_allow || c->device_policy != CGROUP_AUTO)
333 mask |= CGROUP_DEVICE;
338 static CGroupControllerMask unit_get_cgroup_mask(Unit *u) {
341 c = unit_get_cgroup_context(u);
345 return cgroup_context_get_mask(c);
348 static CGroupControllerMask unit_get_members_mask(Unit *u) {
350 return u->cgroup_members_mask;
353 static CGroupControllerMask unit_get_siblings_mask(Unit *u) {
356 if (!UNIT_ISSET(u->slice))
359 /* Sibling propagation is only relevant for weight-based
360 * controllers, so let's mask out everything else */
361 return unit_get_members_mask(UNIT_DEREF(u->slice)) &
362 (CGROUP_CPU|CGROUP_BLKIO|CGROUP_CPUACCT);
365 static CGroupControllerMask unit_get_target_mask(Unit *u) {
366 CGroupControllerMask mask;
368 mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
369 mask &= u->manager->cgroup_supported;
374 /* Recurse from a unit up through its containing slices, propagating
375 * mask bits upward. A unit is also member of itself. */
376 void unit_update_member_masks(Unit *u) {
377 u->cgroup_members_mask |= unit_get_cgroup_mask(u);
378 if (UNIT_ISSET(u->slice)) {
379 Unit *s = UNIT_DEREF(u->slice);
380 s->cgroup_members_mask |= u->cgroup_members_mask;
381 unit_update_member_masks(s);
385 static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) {
386 _cleanup_free_ char *path;
388 bool was_in_hash = false;
392 path = unit_default_cgroup_path(u);
396 r = hashmap_put(u->manager->cgroup_unit, path, u);
400 log_error(r == -EEXIST ?
401 "cgroup %s exists already: %s" : "hashmap_put failed for %s: %s",
406 /* First, create our own group */
407 r = cg_create_everywhere(u->manager->cgroup_supported, mask, path);
409 log_error("Failed to create cgroup %s: %s", path, strerror(-r));
411 /* Then, possibly move things over */
412 if (u->cgroup_path) {
413 r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, path);
415 log_error("Failed to migrate cgroup from %s to %s: %s",
416 u->cgroup_path, path, strerror(-r));
420 /* Remember the new data */
421 free(u->cgroup_path);
422 u->cgroup_path = path;
426 u->cgroup_realized = true;
427 u->cgroup_mask = mask;
432 static bool unit_has_mask_realized(Unit *u, CGroupControllerMask mask) {
433 return u->cgroup_realized && u->cgroup_mask == mask;
436 /* Check if necessary controllers and attributes for a unit are in place.
439 * If not, create paths, move processes over, and set attributes.
441 * Returns 0 on success and < 0 on failure. */
442 static int unit_realize_cgroup_now(Unit *u) {
443 CGroupControllerMask mask;
448 if (u->in_cgroup_queue) {
449 LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
450 u->in_cgroup_queue = false;
453 mask = unit_get_target_mask(u);
455 /* TODO: Consider skipping this check. It may be redundant. */
456 if (unit_has_mask_realized(u, mask))
459 /* First, realize parents */
460 if (UNIT_ISSET(u->slice)) {
461 r = unit_realize_cgroup_now(UNIT_DEREF(u->slice));
466 /* And then do the real work */
467 r = unit_create_cgroups(u, mask);
471 /* Finally, apply the necessary attributes. */
472 cgroup_context_apply(unit_get_cgroup_context(u), mask, u->cgroup_path);
477 static void unit_add_to_cgroup_queue(Unit *u) {
479 if (u->in_cgroup_queue)
482 LIST_PREPEND(cgroup_queue, u->manager->cgroup_queue, u);
483 u->in_cgroup_queue = true;
486 unsigned manager_dispatch_cgroup_queue(Manager *m) {
491 while ((i = m->cgroup_queue)) {
492 assert(i->in_cgroup_queue);
494 r = unit_realize_cgroup_now(i);
496 log_warning("Failed to realize cgroups for queued unit %s: %s", i->id, strerror(-r));
504 static void unit_queue_siblings(Unit *u) {
507 /* This adds the siblings of the specified unit and the
508 * siblings of all parent units to the cgroup queue. (But
509 * neither the specified unit itself nor the parents.) */
511 while ((slice = UNIT_DEREF(u->slice))) {
515 SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
519 /* Skip units that have a dependency on the slice
520 * but aren't actually in it. */
521 if (UNIT_DEREF(m->slice) != slice)
524 /* No point in doing cgroup application for units
525 * without active processes. */
526 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m)))
529 /* If the unit doesn't need any new controllers
530 * and has current ones realized, it doesn't need
532 if (unit_has_mask_realized(m, unit_get_target_mask(m)))
535 unit_add_to_cgroup_queue(m);
542 int unit_realize_cgroup(Unit *u) {
548 c = unit_get_cgroup_context(u);
552 /* So, here's the deal: when realizing the cgroups for this
553 * unit, we need to first create all parents, but there's more
554 * actually: for the weight-based controllers we also need to
555 * make sure that all our siblings (i.e. units that are in the
556 * same slice as we are) have cgroups, too. Otherwise things
557 * would become very uneven as each of their processes would
558 * get as much resources as all our group together. This call
559 * will synchronously create the parent cgroups, but will
560 * defer work on the siblings to the next event loop
563 /* Add all sibling slices to the cgroup queue. */
564 unit_queue_siblings(u);
566 /* And realize this one now (and apply the values) */
567 r = unit_realize_cgroup_now(u);
572 void unit_destroy_cgroup(Unit *u) {
580 r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !unit_has_name(u, SPECIAL_ROOT_SLICE));
582 log_debug("Failed to destroy cgroup %s: %s", u->cgroup_path, strerror(-r));
584 hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
586 free(u->cgroup_path);
587 u->cgroup_path = NULL;
588 u->cgroup_realized = false;
593 pid_t unit_search_main_pid(Unit *u) {
594 _cleanup_fclose_ FILE *f = NULL;
595 pid_t pid = 0, npid, mypid;
602 if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f) < 0)
606 while (cg_read_pid(f, &npid) > 0) {
612 /* Ignore processes that aren't our kids */
613 if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
617 /* Dang, there's more than one daemonized PID
618 in this group, so we don't know what process
619 is the main process. */
630 int manager_setup_cgroup(Manager *m) {
631 _cleanup_free_ char *path = NULL;
637 /* 0. Be nice to Ingo Molnar #628004 */
638 if (path_is_mount_point("/sys/fs/cgroup/systemd", false) <= 0) {
639 log_warning("No control group support available, not creating root group.");
643 /* 1. Determine hierarchy */
644 free(m->cgroup_root);
645 m->cgroup_root = NULL;
647 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
649 log_error("Cannot determine cgroup we are running in: %s", strerror(-r));
653 /* LEGACY: Already in /system.slice? If so, let's cut this
654 * off. This is to support live upgrades from older systemd
655 * versions where PID 1 was moved there. */
656 if (m->running_as == SYSTEMD_SYSTEM) {
657 e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
659 e = endswith(m->cgroup_root, "/system");
664 /* And make sure to store away the root value without trailing
665 * slash, even for the root dir, so that we can easily prepend
667 if (streq(m->cgroup_root, "/"))
668 m->cgroup_root[0] = 0;
671 r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
673 log_error("Cannot find cgroup mount point: %s", strerror(-r));
677 log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
679 /* 3. Install agent */
680 if (m->running_as == SYSTEMD_SYSTEM) {
681 r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
683 log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
685 log_debug("Installed release agent.");
687 log_debug("Release agent already installed.");
690 /* 4. Make sure we are in the root cgroup */
691 r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, 0);
693 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
697 /* 5. And pin it, so that it cannot be unmounted */
698 if (m->pin_cgroupfs_fd >= 0)
699 close_nointr_nofail(m->pin_cgroupfs_fd);
701 m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
703 log_error("Failed to open pin file: %m");
707 /* 6. Figure out which controllers are supported */
708 m->cgroup_supported = cg_mask_supported();
710 /* 7. Always enable hierarchial support if it exists... */
711 cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
716 void manager_shutdown_cgroup(Manager *m, bool delete) {
719 /* We can't really delete the group, since we are in it. But
721 if (delete && m->cgroup_root)
722 cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
724 if (m->pin_cgroupfs_fd >= 0) {
725 close_nointr_nofail(m->pin_cgroupfs_fd);
726 m->pin_cgroupfs_fd = -1;
729 free(m->cgroup_root);
730 m->cgroup_root = NULL;
733 Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
740 u = hashmap_get(m->cgroup_unit, cgroup);
754 u = hashmap_get(m->cgroup_unit, p);
760 Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
761 _cleanup_free_ char *cgroup = NULL;
769 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
773 return manager_get_unit_by_cgroup(m, cgroup);
776 int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
783 u = manager_get_unit_by_cgroup(m, cgroup);
785 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, true);
787 if (UNIT_VTABLE(u)->notify_cgroup_empty)
788 UNIT_VTABLE(u)->notify_cgroup_empty(u);
790 unit_add_to_gc_queue(u);
797 static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
798 [CGROUP_AUTO] = "auto",
799 [CGROUP_CLOSED] = "closed",
800 [CGROUP_STRICT] = "strict",
803 DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);