/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 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 General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <assert.h> #include <unistd.h> #include <sys/types.h> #include <signal.h> #include <sys/mount.h> #include <fcntl.h> #include "cgroup.h" #include "cgroup-util.h" #include "log.h" int cgroup_bonding_realize(CGroupBonding *b) { int r; assert(b); assert(b->path); assert(b->controller); r = cg_create(b->controller, b->path); if (r < 0) { log_warning("Failed to create cgroup %s:%s: %s", b->controller, b->path, strerror(-r)); return r; } b->realized = true; return 0; } int cgroup_bonding_realize_list(CGroupBonding *first) { CGroupBonding *b; int r; LIST_FOREACH(by_unit, b, first) if ((r = cgroup_bonding_realize(b)) < 0 && b->essential) return r; return 0; } void cgroup_bonding_free(CGroupBonding *b, bool trim) { assert(b); if (b->unit) { CGroupBonding *f; LIST_REMOVE(CGroupBonding, by_unit, b->unit->cgroup_bondings, b); if (streq(b->controller, SYSTEMD_CGROUP_CONTROLLER)) { assert_se(f = hashmap_get(b->unit->manager->cgroup_bondings, b->path)); LIST_REMOVE(CGroupBonding, by_path, f, b); if (f) hashmap_replace(b->unit->manager->cgroup_bondings, b->path, f); else hashmap_remove(b->unit->manager->cgroup_bondings, b->path); } } if (b->realized && b->ours && trim) cg_trim(b->controller, b->path, false); free(b->controller); free(b->path); free(b); } void cgroup_bonding_free_list(CGroupBonding *first, bool remove_or_trim) { CGroupBonding *b, *n; LIST_FOREACH_SAFE(by_unit, b, n, first) cgroup_bonding_free(b, remove_or_trim); } void cgroup_bonding_trim(CGroupBonding *b, bool delete_root) { assert(b); if (b->realized && b->ours) cg_trim(b->controller, b->path, delete_root); } void cgroup_bonding_trim_list(CGroupBonding *first, bool delete_root) { CGroupBonding *b; LIST_FOREACH(by_unit, b, first) cgroup_bonding_trim(b, delete_root); } int cgroup_bonding_install(CGroupBonding *b, pid_t pid) { int r; assert(b); assert(pid >= 0); if ((r = cg_create_and_attach(b->controller, b->path, pid)) < 0) return r; b->realized = true; return 0; } int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) { CGroupBonding *b; int r; LIST_FOREACH(by_unit, b, first) if ((r = cgroup_bonding_install(b, pid)) < 0 && b->essential) return r; return 0; } int cgroup_bonding_set_group_access(CGroupBonding *b, mode_t mode, uid_t uid, gid_t gid) { assert(b); if (!b->realized) return -EINVAL; return cg_set_group_access(b->controller, b->path, mode, uid, gid); } int cgroup_bonding_set_group_access_list(CGroupBonding *first, mode_t mode, uid_t uid, gid_t gid) { CGroupBonding *b; int r; LIST_FOREACH(by_unit, b, first) { r = cgroup_bonding_set_group_access(b, mode, uid, gid); if (r < 0) return r; } return 0; } int cgroup_bonding_set_task_access(CGroupBonding *b, mode_t mode, uid_t uid, gid_t gid, int sticky) { assert(b); if (!b->realized) return -EINVAL; return cg_set_task_access(b->controller, b->path, mode, uid, gid, sticky); } int cgroup_bonding_set_task_access_list(CGroupBonding *first, mode_t mode, uid_t uid, gid_t gid, int sticky) { CGroupBonding *b; int r; LIST_FOREACH(by_unit, b, first) { r = cgroup_bonding_set_task_access(b, mode, uid, gid, sticky); if (r < 0) return r; } return 0; } int cgroup_bonding_kill(CGroupBonding *b, int sig, bool sigcont, Set *s) { assert(b); assert(sig >= 0); /* Don't kill cgroups that aren't ours */ if (!b->ours) return 0; return cg_kill_recursive(b->controller, b->path, sig, sigcont, true, false, s); } int cgroup_bonding_kill_list(CGroupBonding *first, int sig, bool sigcont, Set *s) { CGroupBonding *b; Set *allocated_set = NULL; int ret = -EAGAIN, r; if (!first) return 0; if (!s) if (!(s = allocated_set = set_new(trivial_hash_func, trivial_compare_func))) return -ENOMEM; LIST_FOREACH(by_unit, b, first) { if ((r = cgroup_bonding_kill(b, sig, sigcont, s)) < 0) { if (r == -EAGAIN || r == -ESRCH) continue; ret = r; goto finish; } if (ret < 0 || r > 0) ret = r; } finish: if (allocated_set) set_free(allocated_set); return ret; } /* Returns 1 if the group is empty, 0 if it is not, -EAGAIN if we * cannot know */ int cgroup_bonding_is_empty(CGroupBonding *b) { int r; assert(b); if ((r = cg_is_empty_recursive(b->controller, b->path, true)) < 0) return r; /* If it is empty it is empty */ if (r > 0) return 1; /* It's not only us using this cgroup, so we just don't know */ return b->ours ? 0 : -EAGAIN; } int cgroup_bonding_is_empty_list(CGroupBonding *first) { CGroupBonding *b; LIST_FOREACH(by_unit, b, first) { int r; if ((r = cgroup_bonding_is_empty(b)) < 0) { /* If this returned -EAGAIN, then we don't know if the * group is empty, so let's see if another group can * tell us */ if (r != -EAGAIN) return r; } else return r; } return -EAGAIN; } int manager_setup_cgroup(Manager *m) { char *current = NULL, *path = NULL; int r; char suffix[32]; assert(m); /* 0. Be nice to Ingo Molnar #628004 */ if (path_is_mount_point("/sys/fs/cgroup/systemd", false) <= 0) { log_warning("No control group support available, not creating root group."); return 0; } /* 1. Determine hierarchy */ if ((r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, ¤t)) < 0) { log_error("Cannot determine cgroup we are running in: %s", strerror(-r)); goto finish; } if (m->running_as == MANAGER_SYSTEM) strcpy(suffix, "/system"); else { snprintf(suffix, sizeof(suffix), "/systemd-%lu", (unsigned long) getpid()); char_array_0(suffix); } free(m->cgroup_hierarchy); if (endswith(current, suffix)) { /* We probably got reexecuted and can continue to use our root cgroup */ m->cgroup_hierarchy = current; current = NULL; } else { /* We need a new root cgroup */ m->cgroup_hierarchy = NULL; if (asprintf(&m->cgroup_hierarchy, "%s%s", streq(current, "/") ? "" : current, suffix) < 0) { log_error("Out of memory"); r = -ENOMEM; goto finish; } } /* 2. Show data */ if ((r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, NULL, &path)) < 0) { log_error("Cannot find cgroup mount point: %s", strerror(-r)); goto finish; } log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path); /* 3. Install agent */ if ((r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH)) < 0) log_warning("Failed to install release agent, ignoring: %s", strerror(-r)); else if (r > 0) log_debug("Installed release agent."); else log_debug("Release agent already installed."); /* 4. Realize the group */ if ((r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, 0)) < 0) { log_error("Failed to create root cgroup hierarchy: %s", strerror(-r)); goto finish; } /* 5. And pin it, so that it cannot be unmounted */ if (m->pin_cgroupfs_fd >= 0) close_nointr_nofail(m->pin_cgroupfs_fd); if ((m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK)) < 0) { log_error("Failed to open pin file: %m"); r = -errno; goto finish; } log_debug("Created root group."); finish: free(current); free(path); return r; } void manager_shutdown_cgroup(Manager *m, bool delete) { assert(m); if (delete && m->cgroup_hierarchy) cg_delete(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy); if (m->pin_cgroupfs_fd >= 0) { close_nointr_nofail(m->pin_cgroupfs_fd); m->pin_cgroupfs_fd = -1; } free(m->cgroup_hierarchy); m->cgroup_hierarchy = NULL; } int cgroup_bonding_get(Manager *m, const char *cgroup, CGroupBonding **bonding) { CGroupBonding *b; char *p; assert(m); assert(cgroup); assert(bonding); b = hashmap_get(m->cgroup_bondings, cgroup); if (b) { *bonding = b; return 1; } p = strdup(cgroup); if (!p) return -ENOMEM; for (;;) { char *e; e = strrchr(p, '/'); if (!e || e == p) { free(p); *bonding = NULL; return 0; } *e = 0; b = hashmap_get(m->cgroup_bondings, p); if (b) { free(p); *bonding = b; return 1; } } } int cgroup_notify_empty(Manager *m, const char *group) { CGroupBonding *l, *b; int r; assert(m); assert(group); r = cgroup_bonding_get(m, group, &l); if (r <= 0) return r; LIST_FOREACH(by_path, b, l) { int t; if (!b->unit) continue; t = cgroup_bonding_is_empty_list(b); if (t < 0) { /* If we don't know, we don't know */ if (t != -EAGAIN) log_warning("Failed to check whether cgroup is empty: %s", strerror(errno)); continue; } if (t > 0) { /* If it is empty, let's delete it */ cgroup_bonding_trim_list(b->unit->cgroup_bondings, true); if (UNIT_VTABLE(b->unit)->cgroup_notify_empty) UNIT_VTABLE(b->unit)->cgroup_notify_empty(b->unit); } } return 0; } Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) { CGroupBonding *l, *b; char *group = NULL; assert(m); if (pid <= 1) return NULL; if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &group) < 0) return NULL; l = hashmap_get(m->cgroup_bondings, group); if (!l) { char *slash; while ((slash = strrchr(group, '/'))) { if (slash == group) break; *slash = 0; if ((l = hashmap_get(m->cgroup_bondings, group))) break; } } free(group); LIST_FOREACH(by_path, b, l) { if (!b->unit) continue; if (b->ours) return b->unit; } return NULL; } CGroupBonding *cgroup_bonding_find_list(CGroupBonding *first, const char *controller) { CGroupBonding *b; assert(controller); LIST_FOREACH(by_unit, b, first) if (streq(b->controller, controller)) return b; return NULL; } char *cgroup_bonding_to_string(CGroupBonding *b) { char *r; assert(b); if (asprintf(&r, "%s:%s", b->controller, b->path) < 0) return NULL; return r; } pid_t cgroup_bonding_search_main_pid(CGroupBonding *b) { FILE *f; pid_t pid = 0, npid, mypid; assert(b); if (!b->ours) return 0; if (cg_enumerate_processes(b->controller, b->path, &f) < 0) return 0; 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. */ pid = 0; break; } pid = npid; } fclose(f); return pid; } pid_t cgroup_bonding_search_main_pid_list(CGroupBonding *first) { CGroupBonding *b; pid_t pid; /* Try to find a main pid from this cgroup, but checking if * there's only one PID in the cgroup and returning it. Later * on we might want to add additional, smarter heuristics * here. */ LIST_FOREACH(by_unit, b, first) if ((pid = cgroup_bonding_search_main_pid(b)) != 0) return pid; return 0; }