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 CGroupControllerMask unit_get_cgroup_mask(Unit *u) {
341 c = unit_get_cgroup_context(u);
345 return cgroup_context_get_mask(c);
348 CGroupControllerMask unit_get_members_mask(Unit *u) {
351 if (u->cgroup_members_mask_valid)
352 return u->cgroup_members_mask;
354 u->cgroup_members_mask = 0;
356 if (u->type == UNIT_SLICE) {
360 SET_FOREACH(member, u->dependencies[UNIT_BEFORE], i) {
365 if (UNIT_DEREF(member->slice) != u)
368 u->cgroup_members_mask |=
369 unit_get_cgroup_mask(member) |
370 unit_get_members_mask(member);
374 u->cgroup_members_mask_valid = true;
375 return u->cgroup_members_mask;
378 CGroupControllerMask unit_get_siblings_mask(Unit *u) {
379 CGroupControllerMask m;
383 if (UNIT_ISSET(u->slice))
384 m = unit_get_members_mask(UNIT_DEREF(u->slice));
386 m = unit_get_cgroup_mask(u) | unit_get_members_mask(u);
388 /* Sibling propagation is only relevant for weight-based
389 * controllers, so let's mask out everything else */
390 return m & (CGROUP_CPU|CGROUP_BLKIO|CGROUP_CPUACCT);
393 CGroupControllerMask unit_get_target_mask(Unit *u) {
394 CGroupControllerMask mask;
396 mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
397 mask &= u->manager->cgroup_supported;
402 /* Recurse from a unit up through its containing slices, propagating
403 * mask bits upward. A unit is also member of itself. */
404 void unit_update_cgroup_members_masks(Unit *u) {
405 CGroupControllerMask m;
410 /* Calculate subtree mask */
411 m = unit_get_cgroup_mask(u) | unit_get_members_mask(u);
413 /* See if anything changed from the previous invocation. If
414 * not, we're done. */
415 if (u->cgroup_subtree_mask_valid && m == u->cgroup_subtree_mask)
419 u->cgroup_subtree_mask_valid &&
420 ((m & ~u->cgroup_subtree_mask) != 0) &&
421 ((~m & u->cgroup_subtree_mask) == 0);
423 u->cgroup_subtree_mask = m;
424 u->cgroup_subtree_mask_valid = true;
426 if (UNIT_ISSET(u->slice)) {
427 Unit *s = UNIT_DEREF(u->slice);
430 /* There's more set now than before. We
431 * propagate the new mask to the parent's mask
432 * (not caring if it actually was valid or
435 s->cgroup_members_mask |= m;
438 /* There's less set now than before (or we
439 * don't know), we need to recalculate
440 * everything, so let's invalidate the
441 * parent's members mask */
443 s->cgroup_members_mask_valid = false;
445 /* And now make sure that this change also hits our
447 unit_update_cgroup_members_masks(s);
451 static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) {
452 _cleanup_free_ char *path;
453 bool was_in_hash = false;
458 path = unit_default_cgroup_path(u);
462 r = hashmap_put(u->manager->cgroup_unit, path, u);
466 log_error(r == -EEXIST ?
467 "cgroup %s exists already: %s" : "hashmap_put failed for %s: %s",
472 /* First, create our own group */
473 r = cg_create_everywhere(u->manager->cgroup_supported, mask, path);
475 log_error("Failed to create cgroup %s: %s", path, strerror(-r));
477 /* Then, possibly move things over */
478 if (u->cgroup_path) {
479 r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, path);
481 log_error("Failed to migrate cgroup from %s to %s: %s",
482 u->cgroup_path, path, strerror(-r));
486 /* Remember the new data */
487 free(u->cgroup_path);
488 u->cgroup_path = path;
492 u->cgroup_realized = true;
493 u->cgroup_realized_mask = mask;
498 static bool unit_has_mask_realized(Unit *u, CGroupControllerMask mask) {
501 return u->cgroup_realized && u->cgroup_realized_mask == mask;
504 /* Check if necessary controllers and attributes for a unit are in place.
507 * If not, create paths, move processes over, and set attributes.
509 * Returns 0 on success and < 0 on failure. */
510 static int unit_realize_cgroup_now(Unit *u) {
511 CGroupControllerMask mask;
516 if (u->in_cgroup_queue) {
517 LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
518 u->in_cgroup_queue = false;
521 mask = unit_get_target_mask(u);
523 if (unit_has_mask_realized(u, mask))
526 /* First, realize parents */
527 if (UNIT_ISSET(u->slice)) {
528 r = unit_realize_cgroup_now(UNIT_DEREF(u->slice));
533 /* And then do the real work */
534 r = unit_create_cgroups(u, mask);
538 /* Finally, apply the necessary attributes. */
539 cgroup_context_apply(unit_get_cgroup_context(u), mask, u->cgroup_path);
544 static void unit_add_to_cgroup_queue(Unit *u) {
546 if (u->in_cgroup_queue)
549 LIST_PREPEND(cgroup_queue, u->manager->cgroup_queue, u);
550 u->in_cgroup_queue = true;
553 unsigned manager_dispatch_cgroup_queue(Manager *m) {
558 while ((i = m->cgroup_queue)) {
559 assert(i->in_cgroup_queue);
561 r = unit_realize_cgroup_now(i);
563 log_warning("Failed to realize cgroups for queued unit %s: %s", i->id, strerror(-r));
571 static void unit_queue_siblings(Unit *u) {
574 /* This adds the siblings of the specified unit and the
575 * siblings of all parent units to the cgroup queue. (But
576 * neither the specified unit itself nor the parents.) */
578 while ((slice = UNIT_DEREF(u->slice))) {
582 SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
586 /* Skip units that have a dependency on the slice
587 * but aren't actually in it. */
588 if (UNIT_DEREF(m->slice) != slice)
591 /* No point in doing cgroup application for units
592 * without active processes. */
593 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m)))
596 /* If the unit doesn't need any new controllers
597 * and has current ones realized, it doesn't need
599 if (unit_has_mask_realized(m, unit_get_target_mask(m)))
602 unit_add_to_cgroup_queue(m);
609 int unit_realize_cgroup(Unit *u) {
614 c = unit_get_cgroup_context(u);
618 /* So, here's the deal: when realizing the cgroups for this
619 * unit, we need to first create all parents, but there's more
620 * actually: for the weight-based controllers we also need to
621 * make sure that all our siblings (i.e. units that are in the
622 * same slice as we are) have cgroups, too. Otherwise things
623 * would become very uneven as each of their processes would
624 * get as much resources as all our group together. This call
625 * will synchronously create the parent cgroups, but will
626 * defer work on the siblings to the next event loop
629 /* Add all sibling slices to the cgroup queue. */
630 unit_queue_siblings(u);
632 /* And realize this one now (and apply the values) */
633 return unit_realize_cgroup_now(u);
636 void unit_destroy_cgroup(Unit *u) {
644 r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !unit_has_name(u, SPECIAL_ROOT_SLICE));
646 log_debug("Failed to destroy cgroup %s: %s", u->cgroup_path, strerror(-r));
648 hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
650 free(u->cgroup_path);
651 u->cgroup_path = NULL;
652 u->cgroup_realized = false;
653 u->cgroup_realized_mask = 0;
657 pid_t unit_search_main_pid(Unit *u) {
658 _cleanup_fclose_ FILE *f = NULL;
659 pid_t pid = 0, npid, mypid;
666 if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f) < 0)
670 while (cg_read_pid(f, &npid) > 0) {
676 /* Ignore processes that aren't our kids */
677 if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
681 /* Dang, there's more than one daemonized PID
682 in this group, so we don't know what process
683 is the main process. */
694 int manager_setup_cgroup(Manager *m) {
695 _cleanup_free_ char *path = NULL;
701 /* 0. Be nice to Ingo Molnar #628004 */
702 if (path_is_mount_point("/sys/fs/cgroup/systemd", false) <= 0) {
703 log_warning("No control group support available, not creating root group.");
707 /* 1. Determine hierarchy */
708 free(m->cgroup_root);
709 m->cgroup_root = NULL;
711 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
713 log_error("Cannot determine cgroup we are running in: %s", strerror(-r));
717 /* LEGACY: Already in /system.slice? If so, let's cut this
718 * off. This is to support live upgrades from older systemd
719 * versions where PID 1 was moved there. */
720 if (m->running_as == SYSTEMD_SYSTEM) {
721 e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
723 e = endswith(m->cgroup_root, "/system");
728 /* And make sure to store away the root value without trailing
729 * slash, even for the root dir, so that we can easily prepend
731 if (streq(m->cgroup_root, "/"))
732 m->cgroup_root[0] = 0;
735 r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
737 log_error("Cannot find cgroup mount point: %s", strerror(-r));
741 log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
743 /* 3. Install agent */
744 if (m->running_as == SYSTEMD_SYSTEM) {
745 r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
747 log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
749 log_debug("Installed release agent.");
751 log_debug("Release agent already installed.");
754 /* 4. Make sure we are in the root cgroup */
755 r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, 0);
757 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
761 /* 5. And pin it, so that it cannot be unmounted */
762 if (m->pin_cgroupfs_fd >= 0)
763 close_nointr_nofail(m->pin_cgroupfs_fd);
765 m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
767 log_error("Failed to open pin file: %m");
771 /* 6. Figure out which controllers are supported */
772 m->cgroup_supported = cg_mask_supported();
774 /* 7. Always enable hierarchial support if it exists... */
775 cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
780 void manager_shutdown_cgroup(Manager *m, bool delete) {
783 /* We can't really delete the group, since we are in it. But
785 if (delete && m->cgroup_root)
786 cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
788 if (m->pin_cgroupfs_fd >= 0) {
789 close_nointr_nofail(m->pin_cgroupfs_fd);
790 m->pin_cgroupfs_fd = -1;
793 free(m->cgroup_root);
794 m->cgroup_root = NULL;
797 Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
804 u = hashmap_get(m->cgroup_unit, cgroup);
818 u = hashmap_get(m->cgroup_unit, p);
824 Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
825 _cleanup_free_ char *cgroup = NULL;
833 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
837 return manager_get_unit_by_cgroup(m, cgroup);
840 int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
847 u = manager_get_unit_by_cgroup(m, cgroup);
849 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, true);
851 if (UNIT_VTABLE(u)->notify_cgroup_empty)
852 UNIT_VTABLE(u)->notify_cgroup_empty(u);
854 unit_add_to_gc_queue(u);
861 static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
862 [CGROUP_AUTO] = "auto",
863 [CGROUP_CLOSED] = "closed",
864 [CGROUP_STRICT] = "strict",
867 DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);