X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcgroup.c;h=64082d0dc6b64140636d1f10ee209e4fa9deecf3;hp=83fe2ef207e1ddb72b0111a844d407722c3f4abb;hb=d686d8a97bd7945af0a61504392d01a3167b576f;hpb=55096547212928b0ba83fca2595cae0d66d3c0b0 diff --git a/src/cgroup.c b/src/cgroup.c index 83fe2ef20..64082d0dc 100644 --- a/src/cgroup.c +++ b/src/cgroup.c @@ -1,4 +1,4 @@ -/*-*- Mode: C; c-basic-offset: 8 -*-*/ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. @@ -25,8 +25,7 @@ #include #include #include - -#include +#include #include "cgroup.h" #include "cgroup-util.h" @@ -47,7 +46,7 @@ int cgroup_bonding_realize(CGroupBonding *b) { b->realized = true; - if (b->only_us && b->clean_up) + if (b->ours) cg_trim(b->controller, b->path, false); return 0; @@ -58,7 +57,7 @@ int cgroup_bonding_realize_list(CGroupBonding *first) { int r; LIST_FOREACH(by_unit, b, first) - if ((r = cgroup_bonding_realize(b)) < 0) + if ((r = cgroup_bonding_realize(b)) < 0 && b->essential) return r; return 0; @@ -72,16 +71,18 @@ void cgroup_bonding_free(CGroupBonding *b) { LIST_REMOVE(CGroupBonding, by_unit, b->unit->meta.cgroup_bondings, b); - assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path)); - LIST_REMOVE(CGroupBonding, by_path, f, b); + if (streq(b->controller, SYSTEMD_CGROUP_CONTROLLER)) { + assert_se(f = hashmap_get(b->unit->meta.manager->cgroup_bondings, b->path)); + LIST_REMOVE(CGroupBonding, by_path, f, b); - if (f) - hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f); - else - hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path); + if (f) + hashmap_replace(b->unit->meta.manager->cgroup_bondings, b->path, f); + else + hashmap_remove(b->unit->meta.manager->cgroup_bondings, b->path); + } } - if (b->realized && b->only_us && b->clean_up) { + if (b->realized && b->ours) { if (cgroup_bonding_is_empty(b) > 0) cg_delete(b->controller, b->path); @@ -104,7 +105,7 @@ void cgroup_bonding_free_list(CGroupBonding *first) { void cgroup_bonding_trim(CGroupBonding *b, bool delete_root) { assert(b); - if (b->realized && b->only_us && b->clean_up) + if (b->realized && b->ours) cg_trim(b->controller, b->path, delete_root); } @@ -133,42 +134,50 @@ int cgroup_bonding_install_list(CGroupBonding *first, pid_t pid) { int r; LIST_FOREACH(by_unit, b, first) - if ((r = cgroup_bonding_install(b, pid)) < 0) + if ((r = cgroup_bonding_install(b, pid)) < 0 && b->essential) return r; return 0; } -int cgroup_bonding_kill(CGroupBonding *b, int sig) { - int r; - +int cgroup_bonding_kill(CGroupBonding *b, int sig, Set *s) { assert(b); assert(sig >= 0); - if ((r = cgroup_bonding_realize(b)) < 0) - return r; - - assert(b->realized); + /* Don't kill cgroups that aren't ours */ + if (!b->realized || !b->ours) + return 0; - return cg_kill_recursive(b->controller, b->path, sig, true); + return cg_kill_recursive(b->controller, b->path, sig, true, false, s); } -int cgroup_bonding_kill_list(CGroupBonding *first, int sig) { +int cgroup_bonding_kill_list(CGroupBonding *first, int sig, Set *s) { CGroupBonding *b; - int r = -EAGAIN; + Set *allocated_set = NULL; + int ret = -EAGAIN, r; + + 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)) < 0) { + if ((r = cgroup_bonding_kill(b, sig, s)) < 0) { if (r == -EAGAIN || r == -ESRCH) continue; - return r; + ret = r; + goto finish; } - return 0; + if (ret < 0 || r > 0) + ret = r; } - return 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 @@ -186,7 +195,7 @@ int cgroup_bonding_is_empty(CGroupBonding *b) { return 1; /* It's not only us using this cgroup, so we just don't know */ - return b->only_us ? 0 : -EAGAIN; + return b->ours ? 0 : -EAGAIN; } int cgroup_bonding_is_empty_list(CGroupBonding *first) { @@ -210,71 +219,89 @@ int cgroup_bonding_is_empty_list(CGroupBonding *first) { } int manager_setup_cgroup(Manager *m) { - char *cp; + char *current = NULL, *path = NULL; int r; - pid_t pid; char suffix[32]; assert(m); - if ((r = cgroup_init()) != 0) { - log_error("Failed to initialize libcg: %s", cgroup_strerror(r)); - return cg_translate_error(r, errno); - } - - free(m->cgroup_mount_point); - m->cgroup_mount_point = NULL; - if ((r = cgroup_get_subsys_mount_point(SYSTEMD_CGROUP_CONTROLLER, &m->cgroup_mount_point))) - return cg_translate_error(r, errno); - - pid = getpid(); - - if ((r = cgroup_get_current_controller_path(pid, SYSTEMD_CGROUP_CONTROLLER, &cp))) - return cg_translate_error(r, errno); + /* 1. Determine hierarchy */ + if ((r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, ¤t)) < 0) + goto finish; - snprintf(suffix, sizeof(suffix), "/systemd-%u", (unsigned) pid); - char_array_0(suffix); + 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(cp, suffix)) + if (endswith(current, suffix)) { /* We probably got reexecuted and can continue to use our root cgroup */ - m->cgroup_hierarchy = cp; - else { - /* We need a new root cgroup */ + m->cgroup_hierarchy = current; + current = NULL; + } else { + /* We need a new root cgroup */ m->cgroup_hierarchy = NULL; - r = asprintf(&m->cgroup_hierarchy, "%s%s", streq(cp, "/") ? "" : cp, suffix); - free(cp); - - if (r < 0) - return -ENOMEM; + if (asprintf(&m->cgroup_hierarchy, "%s%s", streq(current, "/") ? "" : current, suffix) < 0) { + r = -ENOMEM; + goto finish; + } } - log_debug("Using cgroup controller <" SYSTEMD_CGROUP_CONTROLLER ">, hierarchy mounted at <%s>, using root group <%s>.", - m->cgroup_mount_point, - m->cgroup_hierarchy); + /* 2. Show data */ + if ((r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, NULL, &path)) < 0) + goto finish; + + log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER ". File system hierarchy is at %s.", path); - if ((r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, CGROUP_AGENT_PATH)) < 0) + /* 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("Installed release agent, or already installed."); + log_debug("Release agent already installed."); - if ((r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy, 0)) < 0) + /* 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)); - else - log_debug("Created root group."); + 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) { + r = -errno; + goto finish; + } + + log_debug("Created root group."); + +finish: + free(current); + free(path); return r; } -int manager_shutdown_cgroup(Manager *m) { +void manager_shutdown_cgroup(Manager *m, bool delete) { assert(m); - if (!m->cgroup_hierarchy) - return 0; + 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; + } - return cg_delete(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_hierarchy); + free(m->cgroup_hierarchy); + m->cgroup_hierarchy = NULL; } int cgroup_notify_empty(Manager *m, const char *group) { @@ -312,17 +339,31 @@ int cgroup_notify_empty(Manager *m, const char *group) { Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) { CGroupBonding *l, *b; char *group = NULL; - int r; assert(m); if (pid <= 1) return NULL; - if ((r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &group))) + 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) { @@ -330,7 +371,7 @@ Unit* cgroup_unit_by_pid(Manager *m, pid_t pid) { if (!b->unit) continue; - if (b->only_us) + if (b->ours) return b->unit; } @@ -359,3 +400,54 @@ char *cgroup_bonding_to_string(CGroupBonding *b) { return r; } + +pid_t cgroup_bonding_search_main_pid(CGroupBonding *b) { + FILE *f; + pid_t pid = 0, npid; + int r; + + assert(b); + + if (!b->ours) + return 0; + + if ((r = cg_enumerate_processes(b->controller, b->path, &f)) < 0) + return 0; + + while ((r = cg_read_pid(f, &npid)) > 0) { + + if (npid == pid) + continue; + + if (pid != 0) { + /* Dang, there's more than one 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; + +}