diff options
Diffstat (limited to 'src/basic/cgroup-util.c')
-rw-r--r-- | src/basic/cgroup-util.c | 752 |
1 files changed, 517 insertions, 235 deletions
diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c index 98adace55a..218de0b376 100644 --- a/src/basic/cgroup-util.c +++ b/src/basic/cgroup-util.c @@ -443,105 +443,169 @@ int cg_migrate_recursive_fallback( return r; } -static const char *normalize_controller(const char *controller) { +static const char *controller_to_dirname(const char *controller) { + const char *e; assert(controller); - if (startswith(controller, "name=")) - return controller + 5; - else - return controller; + /* Converts a controller name to the directory name below + * /sys/fs/cgroup/ we want to mount it to. Effectively, this + * just cuts off the name= prefixed used for named + * hierarchies, if it is specified. */ + + e = startswith(controller, "name="); + if (e) + return e; + + return controller; } -static int join_path(const char *controller, const char *path, const char *suffix, char **fs) { +static int join_path_legacy(const char *controller_dn, const char *path, const char *suffix, char **fs) { char *t = NULL; - if (!isempty(controller)) { - if (!isempty(path) && !isempty(suffix)) - t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL); - else if (!isempty(path)) - t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL); - else if (!isempty(suffix)) - t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL); - else - t = strappend("/sys/fs/cgroup/", controller); - } else { - if (!isempty(path) && !isempty(suffix)) - t = strjoin(path, "/", suffix, NULL); - else if (!isempty(path)) - t = strdup(path); - else - return -EINVAL; - } + assert(fs); + assert(controller_dn); + + if (isempty(path) && isempty(suffix)) + t = strappend("/sys/fs/cgroup/", controller_dn); + else if (isempty(path)) + t = strjoin("/sys/fs/cgroup/", controller_dn, "/", suffix, NULL); + else if (isempty(suffix)) + t = strjoin("/sys/fs/cgroup/", controller_dn, "/", path, NULL); + else + t = strjoin("/sys/fs/cgroup/", controller_dn, "/", path, "/", suffix, NULL); + if (!t) + return -ENOMEM; + *fs = t; + return 0; +} + +static int join_path_unified(const char *path, const char *suffix, char **fs) { + char *t; + + assert(fs); + + if (isempty(path) && isempty(suffix)) + t = strdup("/sys/fs/cgroup"); + else if (isempty(path)) + t = strappend("/sys/fs/cgroup/", suffix); + else if (isempty(suffix)) + t = strappend("/sys/fs/cgroup/", path); + else + t = strjoin("/sys/fs/cgroup/", path, "/", suffix, NULL); if (!t) return -ENOMEM; - *fs = path_kill_slashes(t); + *fs = t; return 0; } int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) { - const char *p; - static thread_local bool good = false; + int unified, r; assert(fs); - if (controller && !cg_controller_is_valid(controller)) + if (!controller) { + char *t; + + /* If no controller is specified, we assume only the + * path below the controller matters */ + + if (!path && !suffix) + return -EINVAL; + + if (isempty(suffix)) + t = strdup(path); + else if (isempty(path)) + t = strdup(suffix); + else + t = strjoin(path, "/", suffix, NULL); + if (!t) + return -ENOMEM; + + *fs = path_kill_slashes(t); + return 0; + } + + if (!cg_controller_is_valid(controller)) return -EINVAL; - if (_unlikely_(!good)) { - int r; + unified = cg_unified(); + if (unified < 0) + return unified; - r = path_is_mount_point("/sys/fs/cgroup", 0); - if (r < 0) - return r; - if (r == 0) - return -ENOENT; + if (unified > 0) + r = join_path_unified(path, suffix, fs); + else { + const char *dn; - /* Cache this to save a few stat()s */ - good = true; + if (controller) + dn = controller_to_dirname(controller); + else + dn = NULL; + + r = join_path_legacy(dn, path, suffix, fs); } - p = controller ? normalize_controller(controller) : NULL; + if (r < 0) + return r; - return join_path(p, path, suffix, fs); + path_kill_slashes(*fs); + return 0; } -static int check_hierarchy(const char *p) { - const char *cc; +static int controller_is_accessible(const char *controller) { + int unified; - assert(p); + assert(controller); - if (!filename_is_valid(p)) - return 0; + /* Checks whether a specific controller is accessible, + * i.e. its hierarchy mounted. In the unified hierarchy all + * controllers are considered accessible, except for the named + * hierarchies */ - /* Check if this controller actually really exists */ - cc = strjoina("/sys/fs/cgroup/", p); - if (laccess(cc, F_OK) < 0) - return -errno; + if (!cg_controller_is_valid(controller)) + return -EINVAL; + + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) { + /* We don't support named hierarchies if we are using + * the unified hierarchy. */ + + if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) + return 0; + + if (startswith(controller, "name=")) + return -EOPNOTSUPP; + + } else { + const char *cc, *dn; + + dn = controller_to_dirname(controller); + cc = strjoina("/sys/fs/cgroup/", dn); + + if (laccess(cc, F_OK) < 0) + return -errno; + } return 0; } int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) { - const char *p; int r; + assert(controller); assert(fs); - if (!cg_controller_is_valid(controller)) - return -EINVAL; - - /* Normalize the controller syntax */ - p = normalize_controller(controller); - - /* Check if this controller actually really exists */ - r = check_hierarchy(p); + /* Check if the specified controller is actually accessible */ + r = controller_is_accessible(controller); if (r < 0) return r; - return join_path(p, path, suffix, fs); + return cg_get_path(controller, path, suffix, fs); } static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) { @@ -587,20 +651,6 @@ int cg_trim(const char *controller, const char *path, bool delete_root) { return r; } -int cg_delete(const char *controller, const char *path) { - _cleanup_free_ char *parent = NULL; - int r; - - assert(path); - - r = path_get_parent(path, &parent); - if (r < 0) - return r; - - r = cg_migrate_recursive(controller, path, controller, parent, false, true); - return r == -ENOENT ? 0 : r; -} - int cg_create(const char *controller, const char *path) { _cleanup_free_ char *fs = NULL; int r; @@ -718,7 +768,7 @@ int cg_set_task_access( gid_t gid) { _cleanup_free_ char *fs = NULL, *procs = NULL; - int r; + int r, unified; assert(path); @@ -736,77 +786,88 @@ int cg_set_task_access( if (r < 0) return r; + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified) + return 0; + /* Compatibility, Always keep values for "tasks" in sync with * "cgroup.procs" */ - r = cg_get_path(controller, path, "tasks", &procs); - if (r < 0) - return r; + if (cg_get_path(controller, path, "tasks", &procs) >= 0) + (void) chmod_and_chown(procs, mode, uid, gid); - return chmod_and_chown(procs, mode, uid, gid); + return 0; } int cg_pid_get_path(const char *controller, pid_t pid, char **path) { _cleanup_fclose_ FILE *f = NULL; char line[LINE_MAX]; const char *fs; - size_t cs; + size_t cs = 0; + int unified; assert(path); assert(pid >= 0); - if (controller) { - if (!cg_controller_is_valid(controller)) - return -EINVAL; + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified == 0) { + if (controller) { + if (!cg_controller_is_valid(controller)) + return -EINVAL; + } else + controller = SYSTEMD_CGROUP_CONTROLLER; - controller = normalize_controller(controller); - } else - controller = SYSTEMD_CGROUP_CONTROLLER; + cs = strlen(controller); + } fs = procfs_file_alloca(pid, "cgroup"); - f = fopen(fs, "re"); if (!f) return errno == ENOENT ? -ESRCH : -errno; - cs = strlen(controller); - FOREACH_LINE(line, f, return -errno) { - char *l, *p, *e; - size_t k; - const char *word, *state; - bool found = false; + char *e, *p; truncate_nl(line); - l = strchr(line, ':'); - if (!l) - continue; - - l++; - e = strchr(l, ':'); - if (!e) - continue; + if (unified) { + e = startswith(line, "0:"); + if (!e) + continue; - *e = 0; + e = strchr(e, ':'); + if (!e) + continue; + } else { + char *l; + size_t k; + const char *word, *state; + bool found = false; + + l = strchr(line, ':'); + if (!l) + continue; - FOREACH_WORD_SEPARATOR(word, k, l, ",", state) { + l++; + e = strchr(l, ':'); + if (!e) + continue; - if (k == cs && memcmp(word, controller, cs) == 0) { - found = true; - break; + *e = 0; + FOREACH_WORD_SEPARATOR(word, k, l, ",", state) { + if (k == cs && memcmp(word, controller, cs) == 0) { + found = true; + break; + } } - if (k == 5 + cs && - memcmp(word, "name=", 5) == 0 && - memcmp(word+5, controller, cs) == 0) { - found = true; - break; - } + if (!found) + continue; } - if (!found) - continue; - p = strdup(e + 1); if (!p) return -ENOMEM; @@ -820,11 +881,17 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) { int cg_install_release_agent(const char *controller, const char *agent) { _cleanup_free_ char *fs = NULL, *contents = NULL; - char *sc; - int r; + const char *sc; + int r, unified; assert(agent); + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified) /* doesn't apply to unified hierarchy */ + return -EOPNOTSUPP; + r = cg_get_path(controller, NULL, "release_agent", &fs); if (r < 0) return r; @@ -868,7 +935,13 @@ int cg_install_release_agent(const char *controller, const char *agent) { int cg_uninstall_release_agent(const char *controller) { _cleanup_free_ char *fs = NULL; - int r; + int r, unified; + + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified) /* Doesn't apply to unified hierarchy */ + return -EOPNOTSUPP; r = cg_get_path(controller, NULL, "notify_on_release", &fs); if (r < 0) @@ -893,7 +966,7 @@ int cg_uninstall_release_agent(const char *controller) { int cg_is_empty(const char *controller, const char *path) { _cleanup_fclose_ FILE *f = NULL; - pid_t pid = 0; + pid_t pid; int r; assert(path); @@ -912,49 +985,69 @@ int cg_is_empty(const char *controller, const char *path) { } int cg_is_empty_recursive(const char *controller, const char *path) { - _cleanup_closedir_ DIR *d = NULL; - char *fn; - int r; + int unified, r; assert(path); /* The root cgroup is always populated */ if (controller && (isempty(path) || path_equal(path, "/"))) - return 0; + return false; - r = cg_is_empty(controller, path); - if (r <= 0) - return r; + unified = cg_unified(); + if (unified < 0) + return unified; - r = cg_enumerate_subgroups(controller, path, &d); - if (r == -ENOENT) - return 1; - if (r < 0) - return r; + if (unified > 0) { + _cleanup_free_ char *populated = NULL, *t = NULL; - while ((r = cg_read_subgroup(d, &fn)) > 0) { - _cleanup_free_ char *p = NULL; + /* On the unified hierarchy we can check empty state + * via the "cgroup.populated" attribute. */ - p = strjoin(path, "/", fn, NULL); - free(fn); - if (!p) - return -ENOMEM; + r = cg_get_path(controller, path, "cgroup.populated", &populated); + if (r < 0) + return r; + + r = read_one_line_file(populated, &t); + if (r < 0) + return r; + + return streq(t, "0"); + } else { + _cleanup_closedir_ DIR *d = NULL; + char *fn; - r = cg_is_empty_recursive(controller, p); + r = cg_is_empty(controller, path); if (r <= 0) return r; - } - if (r < 0) - return r; + r = cg_enumerate_subgroups(controller, path, &d); + if (r == -ENOENT) + return 1; + if (r < 0) + return r; - return 1; + 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 = cg_is_empty_recursive(controller, p); + if (r <= 0) + return r; + } + if (r < 0) + return r; + + return true; + } } int cg_split_spec(const char *spec, char **controller, char **path) { - const char *e; char *t = NULL, *u = NULL; - _cleanup_free_ char *v = NULL; + const char *e; assert(spec); @@ -982,7 +1075,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) { return -EINVAL; if (controller) { - t = strdup(normalize_controller(spec)); + t = strdup(spec); if (!t) return -ENOMEM; @@ -995,10 +1088,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) { return 0; } - v = strndup(spec, e-spec); - if (!v) - return -ENOMEM; - t = strdup(normalize_controller(v)); + t = strndup(spec, e-spec); if (!t) return -ENOMEM; if (!cg_controller_is_valid(t)) { @@ -1006,13 +1096,9 @@ int cg_split_spec(const char *spec, char **controller, char **path) { return -EINVAL; } - if (streq(e+1, "")) { - u = strdup("/"); - if (!u) { - free(t); - return -ENOMEM; - } - } else { + if (isempty(e+1)) + u = NULL; + else { u = strdup(e+1); if (!u) { free(t); @@ -1066,7 +1152,7 @@ int cg_mangle_path(const char *path, char **result) { if (r < 0) return r; - return cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result); + return cg_get_path(c ?: SYSTEMD_CGROUP_CONTROLLER, p ?: "/", NULL, result); } int cg_get_root_path(char **path) { @@ -1079,7 +1165,11 @@ int cg_get_root_path(char **path) { if (r < 0) return r; - e = endswith(p, "/" SPECIAL_SYSTEM_SLICE); + e = endswith(p, "/" SPECIAL_INIT_SCOPE); + if (!e) + e = endswith(p, "/" SPECIAL_SYSTEM_SLICE); /* legacy */ + if (!e) + e = endswith(p, "/system"); /* even more legacy */ if (e) *e = 0; @@ -1107,7 +1197,7 @@ int cg_shift_path(const char *cgroup, const char *root, const char **shifted) { } p = path_startswith(cgroup, root); - if (p) + if (p && p > cgroup) *shifted = p - 1; else *shifted = cgroup; @@ -1371,17 +1461,15 @@ int cg_pid_get_user_unit(pid_t pid, char **unit) { } int cg_path_get_machine_name(const char *path, char **machine) { - _cleanup_free_ char *u = NULL, *sl = NULL; + _cleanup_free_ char *u = NULL; + const char *sl; int r; r = cg_path_get_unit(path, &u); if (r < 0) return r; - sl = strjoin("/run/systemd/machines/unit:", u, NULL); - if (!sl) - return -ENOMEM; - + sl = strjoina("/run/systemd/machines/unit:", u); return readlink_malloc(sl, machine); } @@ -1574,31 +1662,38 @@ char *cg_escape(const char *p) { p[0] == '.' || streq(p, "notify_on_release") || streq(p, "release_agent") || - streq(p, "tasks")) + streq(p, "tasks") || + startswith(p, "cgroup.")) need_prefix = true; else { const char *dot; dot = strrchr(p, '.'); if (dot) { + CGroupController c; + size_t l = dot - p; - if (dot - p == 6 && memcmp(p, "cgroup", 6) == 0) - need_prefix = true; - else { - char *n; + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + const char *n; + + n = cgroup_controller_to_string(c); - n = strndupa(p, dot - p); + if (l != strlen(n)) + continue; - if (check_hierarchy(n) >= 0) - need_prefix = true; + if (memcmp(p, n, l) != 0) + continue; + + need_prefix = true; + break; } } } if (need_prefix) return strappend("_", p); - else - return strdup(p); + + return strdup(p); } char *cg_unescape(const char *p) { @@ -1731,17 +1826,9 @@ int cg_get_attribute(const char *controller, const char *path, const char *attri return read_one_line_file(p, ret); } -static const char mask_names[] = - "cpu\0" - "cpuacct\0" - "blkio\0" - "memory\0" - "devices\0"; - -int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path) { - CGroupControllerMask bit = 1; - const char *n; - int r; +int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) { + CGroupController c; + int r, unified; /* This one will create a cgroup in our private tree, but also * duplicate it in the trees specified in mask, and remove it @@ -1752,49 +1839,63 @@ int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask ma if (r < 0) return r; - /* Then, do the same in the other hierarchies */ - NULSTR_FOREACH(n, mask_names) { + /* If we are in the unified hierarchy, we are done now */ + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) + return 0; + + /* Otherwise, do the same in the other hierarchies */ + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + const char *n; + + n = cgroup_controller_to_string(c); + if (mask & bit) - cg_create(n, path); + (void) cg_create(n, path); else if (supported & bit) - cg_trim(n, path, true); - - bit <<= 1; + (void) cg_trim(n, path, true); } return 0; } -int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) { - CGroupControllerMask bit = 1; - const char *n; - int r; +int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) { + CGroupController c; + int r, unified; r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid); if (r < 0) return r; - NULSTR_FOREACH(n, mask_names) { + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) + return 0; - if (supported & bit) { - const char *p = NULL; + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + const char *p = NULL; - if (path_callback) - p = path_callback(bit, userdata); + if (!(supported & bit)) + continue; - if (!p) - p = path; + if (path_callback) + p = path_callback(bit, userdata); - cg_attach_fallback(n, p, pid); - } + if (!p) + p = path; - bit <<= 1; + (void) cg_attach_fallback(cgroup_controller_to_string(c), p, pid); } return 0; } -int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) { +int cg_attach_many_everywhere(CGroupMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) { Iterator i; void *pidp; int r = 0; @@ -1804,17 +1905,16 @@ int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, int q; q = cg_attach_everywhere(supported, path, pid, path_callback, userdata); - if (q < 0) + if (q < 0 && r >= 0) r = q; } return r; } -int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) { - CGroupControllerMask bit = 1; - const char *n; - int r; +int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) { + CGroupController c; + int r, unified; if (!path_equal(from, to)) { r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true); @@ -1822,56 +1922,119 @@ int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, cons return r; } - NULSTR_FOREACH(n, mask_names) { - if (supported & bit) { - const char *p = NULL; + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) + return r; - if (to_callback) - p = to_callback(bit, userdata); + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + const char *p = NULL; - if (!p) - p = to; + if (!(supported & bit)) + continue; - cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, p, false, false); - } + if (to_callback) + p = to_callback(bit, userdata); - bit <<= 1; + if (!p) + p = to; + + (void) cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, cgroup_controller_to_string(c), p, false, false); } return 0; } -int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root) { - CGroupControllerMask bit = 1; - const char *n; - int r; +int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) { + CGroupController c; + int r, unified; r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root); if (r < 0) return r; - NULSTR_FOREACH(n, mask_names) { - if (supported & bit) - cg_trim(n, path, delete_root); + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) + return r; + + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + + if (!(supported & bit)) + continue; - bit <<= 1; + (void) cg_trim(cgroup_controller_to_string(c), path, delete_root); } return 0; } -CGroupControllerMask cg_mask_supported(void) { - CGroupControllerMask bit = 1, mask = 0; - const char *n; +int cg_mask_supported(CGroupMask *ret) { + CGroupMask mask = 0; + int r, unified; + + /* Determines the mask of supported cgroup controllers. Only + * includes controllers we can make sense of and that are + * actually accessible. */ - NULSTR_FOREACH(n, mask_names) { - if (check_hierarchy(n) >= 0) - mask |= bit; + unified = cg_unified(); + if (unified < 0) + return unified; + if (unified > 0) { + _cleanup_free_ char *controllers = NULL; + const char *c; + + /* In the unified hierarchy we can read the supported + * and accessible controllers from a the top-level + * cgroup attribute */ + + r = read_one_line_file("/sys/fs/cgroup/cgroup.controllers", &controllers); + if (r < 0) + return r; - bit <<= 1; + c = controllers; + for (;;) { + _cleanup_free_ char *n = NULL; + CGroupController v; + + r = extract_first_word(&c, &n, NULL, 0); + if (r < 0) + return r; + if (r == 0) + break; + + v = cgroup_controller_from_string(n); + if (v < 0) + continue; + + mask |= CGROUP_CONTROLLER_TO_MASK(v); + } + + /* Currently, we only support the memory controller in + * the unified hierarchy, mask everything else off. */ + mask &= CGROUP_MASK_MEMORY; + + } else { + CGroupController c; + + /* In the legacy hierarchy, we check whether which + * hierarchies are mounted. */ + + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + const char *n; + + n = cgroup_controller_to_string(c); + if (controller_is_accessible(n) >= 0) + mask |= CGROUP_CONTROLLER_TO_MASK(c); + } } - return mask; + *ret = mask; + return 0; } int cg_kernel_controllers(Set *controllers) { @@ -1917,7 +2080,7 @@ int cg_kernel_controllers(Set *controllers) { continue; } - if (!filename_is_valid(controller)) { + if (!cg_controller_is_valid(controller)) { free(controller); return -EBADMSG; } @@ -1929,3 +2092,122 @@ int cg_kernel_controllers(Set *controllers) { return 0; } + +static thread_local int unified_cache = -1; + +int cg_unified(void) { + struct statfs fs; + + /* Checks if we support the unified hierarchy. Returns an + * error when the cgroup hierarchies aren't mounted yet or we + * have any other trouble determining if the unified hierarchy + * is supported. */ + + if (unified_cache >= 0) + return unified_cache; + + if (statfs("/sys/fs/cgroup/", &fs) < 0) + return -errno; + + if (F_TYPE_EQUAL(fs.f_type, CGROUP_SUPER_MAGIC)) + unified_cache = true; + else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC)) + unified_cache = false; + else + return -ENOEXEC; + + return unified_cache; +} + +void cg_unified_flush(void) { + unified_cache = -1; +} + +int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) { + _cleanup_free_ char *fs = NULL; + CGroupController c; + int r, unified; + + assert(p); + + if (supported == 0) + return 0; + + unified = cg_unified(); + if (unified < 0) + return unified; + if (!unified) /* on the legacy hiearchy there's no joining of controllers defined */ + return 0; + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, p, "cgroup.subtree_control", &fs); + if (r < 0) + return r; + + for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + const char *n; + + if (!(supported & bit)) + continue; + + n = cgroup_controller_to_string(c); + { + char s[1 + strlen(n) + 1]; + + s[0] = mask & bit ? '+' : '-'; + strcpy(s + 1, n); + + r = write_string_file(fs, s, 0); + if (r < 0) + log_warning_errno(r, "Failed to enable controller %s for %s (%s): %m", n, p, fs); + } + } + + return 0; +} + +bool cg_is_unified_wanted(void) { + static thread_local int wanted = -1; + int r, unified; + + /* If the hierarchy is already mounted, then follow whatever + * was chosen for it. */ + unified = cg_unified(); + if (unified >= 0) + return unified; + + /* Otherwise, let's see what the kernel command line has to + * say. Since checking that is expensive, let's cache the + * result. */ + if (wanted >= 0) + return wanted; + + r = get_proc_cmdline_key("systemd.unified_cgroup_hierarchy", NULL); + if (r > 0) + return (wanted = true); + else { + _cleanup_free_ char *value = NULL; + + r = get_proc_cmdline_key("systemd.unified_cgroup_hierarchy=", &value); + if (r < 0) + return false; + if (r == 0) + return (wanted = false); + + return (wanted = parse_boolean(value) > 0); + } +} + +bool cg_is_legacy_wanted(void) { + return !cg_is_unified_wanted(); +} + +static const char *cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = { + [CGROUP_CONTROLLER_CPU] = "cpu", + [CGROUP_CONTROLLER_CPUACCT] = "cpuacct", + [CGROUP_CONTROLLER_BLKIO] = "blkio", + [CGROUP_CONTROLLER_MEMORY] = "memory", + [CGROUP_CONTROLLER_DEVICE] = "device", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController); |