/*-*- 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); } 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); } } } 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; } 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(SYSTEMD_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(SYSTEMD_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(SYSTEMD_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(SYSTEMD_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(SYSTEMD_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); } } } 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(SYSTEMD_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 && m->running_as == MANAGER_SYSTEM) { 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(SYSTEMD_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 " SYSTEMD_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. */ 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 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(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_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(SYSTEMD_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(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, SYSTEMD_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(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false); 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); m->pin_cgroupfs_fd = safe_close(m->pin_cgroupfs_fd); m->cgroup_root = mfree(m->cgroup_root); } 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(SYSTEMD_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; } 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);