diff options
Diffstat (limited to 'src/core/cgroup.c')
| -rw-r--r-- | src/core/cgroup.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/src/core/cgroup.c b/src/core/cgroup.c new file mode 100644 index 0000000000..1f6139e25f --- /dev/null +++ b/src/core/cgroup.c @@ -0,0 +1,556 @@ +/*-*- 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; + +} |