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) {
349 CGroupControllerMask mask = 0;
355 SET_FOREACH(m, u->dependencies[UNIT_BEFORE], i) {
357 if (UNIT_DEREF(m->slice) != u)
360 mask |= unit_get_cgroup_mask(m) | unit_get_members_mask(m);
366 static CGroupControllerMask unit_get_siblings_mask(Unit *u) {
369 if (!UNIT_ISSET(u->slice))
372 /* Sibling propagation is only relevant for weight-based
373 * controllers, so let's mask out everything else */
374 return unit_get_members_mask(UNIT_DEREF(u->slice)) &
375 (CGROUP_CPU|CGROUP_BLKIO|CGROUP_CPUACCT);
378 static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) {
381 bool is_in_hash = false;
385 path = unit_default_cgroup_path(u);
389 r = hashmap_put(u->manager->cgroup_unit, path, u);
394 log_error("cgroup %s exists already: %s", path, strerror(-r));
399 /* First, create our own group */
400 r = cg_create_everywhere(u->manager->cgroup_supported, mask, path);
402 log_error("Failed to create cgroup %s: %s", path, strerror(-r));
404 /* Then, possibly move things over */
405 if (u->cgroup_path) {
406 r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, path);
408 log_error("Failed to migrate cgroup %s: %s", path, strerror(-r));
412 /* And remember the new data */
413 free(u->cgroup_path);
414 u->cgroup_path = path;
417 u->cgroup_realized = true;
418 u->cgroup_mask = mask;
423 static int unit_realize_cgroup_now(Unit *u) {
424 CGroupControllerMask mask;
428 if (u->in_cgroup_queue) {
429 LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
430 u->in_cgroup_queue = false;
433 mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
434 mask &= u->manager->cgroup_supported;
436 if (u->cgroup_realized &&
437 u->cgroup_mask == mask)
440 /* First, realize parents */
441 if (UNIT_ISSET(u->slice))
442 unit_realize_cgroup_now(UNIT_DEREF(u->slice));
444 /* And then do the real work */
445 return unit_create_cgroups(u, mask);
448 static void unit_add_to_cgroup_queue(Unit *u) {
450 if (u->in_cgroup_queue)
453 LIST_PREPEND(cgroup_queue, u->manager->cgroup_queue, u);
454 u->in_cgroup_queue = true;
457 unsigned manager_dispatch_cgroup_queue(Manager *m) {
461 while ((i = m->cgroup_queue)) {
462 assert(i->in_cgroup_queue);
464 if (unit_realize_cgroup_now(i) >= 0)
465 cgroup_context_apply(unit_get_cgroup_context(i), i->cgroup_mask, i->cgroup_path);
473 static void unit_queue_siblings(Unit *u) {
476 /* This adds the siblings of the specified unit and the
477 * siblings of all parent units to the cgroup queue. (But
478 * neither the specified unit itself nor the parents.) */
480 while ((slice = UNIT_DEREF(u->slice))) {
484 SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
488 if (UNIT_DEREF(m->slice) != slice)
491 unit_add_to_cgroup_queue(m);
498 int unit_realize_cgroup(Unit *u) {
504 c = unit_get_cgroup_context(u);
508 /* So, here's the deal: when realizing the cgroups for this
509 * unit, we need to first create all parents, but there's more
510 * actually: for the weight-based controllers we also need to
511 * make sure that all our siblings (i.e. units that are in the
512 * same slice as we are) have cgroup too. Otherwise things
513 * would become very uneven as each of their processes would
514 * get as much resources as all our group together. This call
515 * will synchronously create the parent cgroups, but will
516 * defer work on the siblings to the next event loop
519 /* Add all sibling slices to the cgroup queue. */
520 unit_queue_siblings(u);
522 /* And realize this one now */
523 r = unit_realize_cgroup_now(u);
525 /* And apply the values */
527 cgroup_context_apply(c, u->cgroup_mask, u->cgroup_path);
532 void unit_destroy_cgroup(Unit *u) {
540 r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !unit_has_name(u, SPECIAL_ROOT_SLICE));
542 log_debug("Failed to destroy cgroup %s: %s", u->cgroup_path, strerror(-r));
544 hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
546 free(u->cgroup_path);
547 u->cgroup_path = NULL;
548 u->cgroup_realized = false;
553 pid_t unit_search_main_pid(Unit *u) {
554 _cleanup_fclose_ FILE *f = NULL;
555 pid_t pid = 0, npid, mypid;
562 if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f) < 0)
566 while (cg_read_pid(f, &npid) > 0) {
572 /* Ignore processes that aren't our kids */
573 if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
577 /* Dang, there's more than one daemonized PID
578 in this group, so we don't know what process
579 is the main process. */
590 int manager_setup_cgroup(Manager *m) {
591 _cleanup_free_ char *path = NULL;
597 /* 0. Be nice to Ingo Molnar #628004 */
598 if (path_is_mount_point("/sys/fs/cgroup/systemd", false) <= 0) {
599 log_warning("No control group support available, not creating root group.");
603 /* 1. Determine hierarchy */
604 free(m->cgroup_root);
605 m->cgroup_root = NULL;
607 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
609 log_error("Cannot determine cgroup we are running in: %s", strerror(-r));
613 /* Already in /system.slice? If so, let's cut this off again */
614 if (m->running_as == SYSTEMD_SYSTEM) {
615 e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
620 /* And make sure to store away the root value without trailing
621 * slash, even for the root dir, so that we can easily prepend
623 if (streq(m->cgroup_root, "/"))
624 m->cgroup_root[0] = 0;
627 r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
629 log_error("Cannot find cgroup mount point: %s", strerror(-r));
633 log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
635 /* 3. Install agent */
636 if (m->running_as == SYSTEMD_SYSTEM) {
637 r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
639 log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
641 log_debug("Installed release agent.");
643 log_debug("Release agent already installed.");
646 /* 4. Realize the system slice and put us in there */
647 if (m->running_as == SYSTEMD_SYSTEM) {
648 a = strappenda(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
649 r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, a, 0);
651 r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, 0);
653 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
657 /* 5. And pin it, so that it cannot be unmounted */
658 if (m->pin_cgroupfs_fd >= 0)
659 close_nointr_nofail(m->pin_cgroupfs_fd);
661 m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
663 log_error("Failed to open pin file: %m");
667 /* 6. Figure out which controllers are supported */
668 m->cgroup_supported = cg_mask_supported();
670 /* 7. Always enable hierarchial support if it exists... */
671 cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
676 void manager_shutdown_cgroup(Manager *m, bool delete) {
679 /* We can't really delete the group, since we are in it. But
681 if (delete && m->cgroup_root)
682 cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
684 if (m->pin_cgroupfs_fd >= 0) {
685 close_nointr_nofail(m->pin_cgroupfs_fd);
686 m->pin_cgroupfs_fd = -1;
689 free(m->cgroup_root);
690 m->cgroup_root = NULL;
693 Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
700 u = hashmap_get(m->cgroup_unit, cgroup);
714 u = hashmap_get(m->cgroup_unit, p);
720 Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
721 _cleanup_free_ char *cgroup = NULL;
729 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
733 return manager_get_unit_by_cgroup(m, cgroup);
736 int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
743 u = manager_get_unit_by_cgroup(m, cgroup);
745 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, true);
747 if (UNIT_VTABLE(u)->notify_cgroup_empty)
748 UNIT_VTABLE(u)->notify_cgroup_empty(u);
750 unit_add_to_gc_queue(u);
757 static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
758 [CGROUP_AUTO] = "auto",
759 [CGROUP_CLOSED] = "closed",
760 [CGROUP_STRICT] = "strict",
763 DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);