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) {
379 _cleanup_free_ char *path;
381 bool was_in_hash = false;
385 path = unit_default_cgroup_path(u);
389 r = hashmap_put(u->manager->cgroup_unit, path, u);
393 log_error(r == -EEXIST ?
394 "cgroup %s exists already: %s" : "hashmap_put failed for %s: %s",
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 from %s to %s: %s",
409 u->cgroup_path, path, strerror(-r));
413 /* Remember the new data */
414 free(u->cgroup_path);
415 u->cgroup_path = path;
419 u->cgroup_realized = true;
420 u->cgroup_mask = mask;
425 static int unit_realize_cgroup_now(Unit *u) {
426 CGroupControllerMask mask;
430 if (u->in_cgroup_queue) {
431 LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
432 u->in_cgroup_queue = false;
435 mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
436 mask &= u->manager->cgroup_supported;
438 if (u->cgroup_realized &&
439 u->cgroup_mask == mask)
442 /* First, realize parents */
443 if (UNIT_ISSET(u->slice))
444 unit_realize_cgroup_now(UNIT_DEREF(u->slice));
446 /* And then do the real work */
447 return unit_create_cgroups(u, mask);
450 static void unit_add_to_cgroup_queue(Unit *u) {
452 if (u->in_cgroup_queue)
455 LIST_PREPEND(cgroup_queue, u->manager->cgroup_queue, u);
456 u->in_cgroup_queue = true;
459 unsigned manager_dispatch_cgroup_queue(Manager *m) {
463 while ((i = m->cgroup_queue)) {
464 assert(i->in_cgroup_queue);
466 if (unit_realize_cgroup_now(i) >= 0)
467 cgroup_context_apply(unit_get_cgroup_context(i), i->cgroup_mask, i->cgroup_path);
475 static void unit_queue_siblings(Unit *u) {
478 /* This adds the siblings of the specified unit and the
479 * siblings of all parent units to the cgroup queue. (But
480 * neither the specified unit itself nor the parents.) */
482 while ((slice = UNIT_DEREF(u->slice))) {
486 SET_FOREACH(m, slice->dependencies[UNIT_BEFORE], i) {
490 if (UNIT_DEREF(m->slice) != slice)
493 unit_add_to_cgroup_queue(m);
500 int unit_realize_cgroup(Unit *u) {
506 c = unit_get_cgroup_context(u);
510 /* So, here's the deal: when realizing the cgroups for this
511 * unit, we need to first create all parents, but there's more
512 * actually: for the weight-based controllers we also need to
513 * make sure that all our siblings (i.e. units that are in the
514 * same slice as we are) have cgroups, too. Otherwise things
515 * would become very uneven as each of their processes would
516 * get as much resources as all our group together. This call
517 * will synchronously create the parent cgroups, but will
518 * defer work on the siblings to the next event loop
521 /* Add all sibling slices to the cgroup queue. */
522 unit_queue_siblings(u);
524 /* And realize this one now */
525 r = unit_realize_cgroup_now(u);
527 /* And apply the values */
529 cgroup_context_apply(c, u->cgroup_mask, u->cgroup_path);
534 void unit_destroy_cgroup(Unit *u) {
542 r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !unit_has_name(u, SPECIAL_ROOT_SLICE));
544 log_debug("Failed to destroy cgroup %s: %s", u->cgroup_path, strerror(-r));
546 hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
548 free(u->cgroup_path);
549 u->cgroup_path = NULL;
550 u->cgroup_realized = false;
555 pid_t unit_search_main_pid(Unit *u) {
556 _cleanup_fclose_ FILE *f = NULL;
557 pid_t pid = 0, npid, mypid;
564 if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f) < 0)
568 while (cg_read_pid(f, &npid) > 0) {
574 /* Ignore processes that aren't our kids */
575 if (get_parent_of_pid(npid, &ppid) >= 0 && ppid != mypid)
579 /* Dang, there's more than one daemonized PID
580 in this group, so we don't know what process
581 is the main process. */
592 int manager_setup_cgroup(Manager *m) {
593 _cleanup_free_ char *path = NULL;
599 /* 0. Be nice to Ingo Molnar #628004 */
600 if (path_is_mount_point("/sys/fs/cgroup/systemd", false) <= 0) {
601 log_warning("No control group support available, not creating root group.");
605 /* 1. Determine hierarchy */
606 free(m->cgroup_root);
607 m->cgroup_root = NULL;
609 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
611 log_error("Cannot determine cgroup we are running in: %s", strerror(-r));
615 /* LEGACY: Already in /system.slice? If so, let's cut this
616 * off. This is to support live upgrades from older systemd
617 * versions where PID 1 was moved there. */
618 if (m->running_as == SYSTEMD_SYSTEM) {
619 e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
621 e = endswith(m->cgroup_root, "/system");
626 /* And make sure to store away the root value without trailing
627 * slash, even for the root dir, so that we can easily prepend
629 if (streq(m->cgroup_root, "/"))
630 m->cgroup_root[0] = 0;
633 r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
635 log_error("Cannot find cgroup mount point: %s", strerror(-r));
639 log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path);
641 /* 3. Install agent */
642 if (m->running_as == SYSTEMD_SYSTEM) {
643 r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
645 log_warning("Failed to install release agent, ignoring: %s", strerror(-r));
647 log_debug("Installed release agent.");
649 log_debug("Release agent already installed.");
652 /* 4. Make sure we are in the root cgroup */
653 r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, 0);
655 log_error("Failed to create root cgroup hierarchy: %s", strerror(-r));
659 /* 5. And pin it, so that it cannot be unmounted */
660 if (m->pin_cgroupfs_fd >= 0)
661 close_nointr_nofail(m->pin_cgroupfs_fd);
663 m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
665 log_error("Failed to open pin file: %m");
669 /* 6. Figure out which controllers are supported */
670 m->cgroup_supported = cg_mask_supported();
672 /* 7. Always enable hierarchial support if it exists... */
673 cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
678 void manager_shutdown_cgroup(Manager *m, bool delete) {
681 /* We can't really delete the group, since we are in it. But
683 if (delete && m->cgroup_root)
684 cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
686 if (m->pin_cgroupfs_fd >= 0) {
687 close_nointr_nofail(m->pin_cgroupfs_fd);
688 m->pin_cgroupfs_fd = -1;
691 free(m->cgroup_root);
692 m->cgroup_root = NULL;
695 Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
702 u = hashmap_get(m->cgroup_unit, cgroup);
716 u = hashmap_get(m->cgroup_unit, p);
722 Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
723 _cleanup_free_ char *cgroup = NULL;
731 r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
735 return manager_get_unit_by_cgroup(m, cgroup);
738 int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
745 u = manager_get_unit_by_cgroup(m, cgroup);
747 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, true);
749 if (UNIT_VTABLE(u)->notify_cgroup_empty)
750 UNIT_VTABLE(u)->notify_cgroup_empty(u);
752 unit_add_to_gc_queue(u);
759 static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
760 [CGROUP_AUTO] = "auto",
761 [CGROUP_CLOSED] = "closed",
762 [CGROUP_STRICT] = "strict",
765 DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);