| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| |
| #include <dirent.h> |
| #include <errno.h> |
| #include <ftw.h> |
| #include <limits.h> |
| #include <signal.h> |
| #include <stddef.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/statfs.h> |
| #include <sys/types.h> |
| #include <sys/utsname.h> |
| #include <sys/xattr.h> |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "cgroup-util.h" |
| #include "def.h" |
| #include "dirent-util.h" |
| #include "extract-word.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "format-util.h" |
| #include "fs-util.h" |
| #include "log.h" |
| #include "login-util.h" |
| #include "macro.h" |
| #include "missing.h" |
| #include "mkdir.h" |
| #include "parse-util.h" |
| #include "path-util.h" |
| #include "proc-cmdline.h" |
| #include "process-util.h" |
| #include "set.h" |
| #include "special.h" |
| #include "stat-util.h" |
| #include "stdio-util.h" |
| #include "string-table.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "unit-name.h" |
| #include "user-util.h" |
| |
| static int cg_enumerate_items(const char *controller, const char *path, FILE **_f, const char *item) { |
| _cleanup_free_ char *fs = NULL; |
| FILE *f; |
| int r; |
| |
| assert(_f); |
| |
| r = cg_get_path(controller, path, item, &fs); |
| if (r < 0) |
| return r; |
| |
| f = fopen(fs, "re"); |
| if (!f) |
| return -errno; |
| |
| *_f = f; |
| return 0; |
| } |
| |
| int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) { |
| return cg_enumerate_items(controller, path, _f, "cgroup.procs"); |
| } |
| |
| int cg_read_pid(FILE *f, pid_t *_pid) { |
| unsigned long ul; |
| |
| /* Note that the cgroup.procs might contain duplicates! See |
| * cgroups.txt for details. */ |
| |
| assert(f); |
| assert(_pid); |
| |
| errno = 0; |
| if (fscanf(f, "%lu", &ul) != 1) { |
| |
| if (feof(f)) |
| return 0; |
| |
| return errno_or_else(EIO); |
| } |
| |
| if (ul <= 0) |
| return -EIO; |
| |
| *_pid = (pid_t) ul; |
| return 1; |
| } |
| |
| int cg_read_event( |
| const char *controller, |
| const char *path, |
| const char *event, |
| char **ret) { |
| |
| _cleanup_free_ char *events = NULL, *content = NULL; |
| int r; |
| |
| r = cg_get_path(controller, path, "cgroup.events", &events); |
| if (r < 0) |
| return r; |
| |
| r = read_full_file(events, &content, NULL); |
| if (r < 0) |
| return r; |
| |
| for (const char *p = content;;) { |
| _cleanup_free_ char *line = NULL, *key = NULL, *val = NULL; |
| const char *q; |
| |
| r = extract_first_word(&p, &line, "\n", 0); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| return -ENOENT; |
| |
| q = line; |
| r = extract_first_word(&q, &key, " ", 0); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| return -EINVAL; |
| |
| if (!streq(key, event)) |
| continue; |
| |
| val = strdup(q); |
| if (!val) |
| return -ENOMEM; |
| |
| *ret = TAKE_PTR(val); |
| return 0; |
| } |
| } |
| |
| bool cg_ns_supported(void) { |
| static thread_local int enabled = -1; |
| |
| if (enabled >= 0) |
| return enabled; |
| |
| if (access("/proc/self/ns/cgroup", F_OK) < 0) { |
| if (errno != ENOENT) |
| log_debug_errno(errno, "Failed to check whether /proc/self/ns/cgroup is available, assuming not: %m"); |
| enabled = false; |
| } else |
| enabled = true; |
| |
| return enabled; |
| } |
| |
| int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) { |
| _cleanup_free_ char *fs = NULL; |
| int r; |
| DIR *d; |
| |
| assert(_d); |
| |
| /* This is not recursive! */ |
| |
| r = cg_get_path(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| d = opendir(fs); |
| if (!d) |
| return -errno; |
| |
| *_d = d; |
| return 0; |
| } |
| |
| int cg_read_subgroup(DIR *d, char **fn) { |
| struct dirent *de; |
| |
| assert(d); |
| assert(fn); |
| |
| FOREACH_DIRENT_ALL(de, d, return -errno) { |
| char *b; |
| |
| if (de->d_type != DT_DIR) |
| continue; |
| |
| if (dot_or_dot_dot(de->d_name)) |
| continue; |
| |
| b = strdup(de->d_name); |
| if (!b) |
| return -ENOMEM; |
| |
| *fn = b; |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| int cg_rmdir(const char *controller, const char *path) { |
| _cleanup_free_ char *p = NULL; |
| int r; |
| |
| r = cg_get_path(controller, path, NULL, &p); |
| if (r < 0) |
| return r; |
| |
| r = rmdir(p); |
| if (r < 0 && errno != ENOENT) |
| return -errno; |
| |
| r = cg_hybrid_unified(); |
| if (r <= 0) |
| return r; |
| |
| if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| r = cg_rmdir(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path); |
| if (r < 0) |
| log_warning_errno(r, "Failed to remove compat systemd cgroup %s: %m", path); |
| } |
| |
| return 0; |
| } |
| |
| static int cg_kill_items( |
| const char *controller, |
| const char *path, |
| int sig, |
| CGroupFlags flags, |
| Set *s, |
| cg_kill_log_func_t log_kill, |
| void *userdata, |
| const char *item) { |
| |
| _cleanup_set_free_ Set *allocated_set = NULL; |
| bool done = false; |
| int r, ret = 0, ret_log_kill = 0; |
| pid_t my_pid; |
| |
| assert(sig >= 0); |
| |
| /* Don't send SIGCONT twice. Also, SIGKILL always works even when process is suspended, hence don't send |
| * SIGCONT on SIGKILL. */ |
| if (IN_SET(sig, SIGCONT, SIGKILL)) |
| flags &= ~CGROUP_SIGCONT; |
| |
| /* This goes through the tasks list and kills them all. This |
| * is repeated until no further processes are added to the |
| * tasks list, to properly handle forking processes */ |
| |
| if (!s) { |
| s = allocated_set = set_new(NULL); |
| if (!s) |
| return -ENOMEM; |
| } |
| |
| my_pid = getpid_cached(); |
| |
| do { |
| _cleanup_fclose_ FILE *f = NULL; |
| pid_t pid = 0; |
| done = true; |
| |
| r = cg_enumerate_items(controller, path, &f, item); |
| if (r < 0) { |
| if (ret >= 0 && r != -ENOENT) |
| return r; |
| |
| return ret; |
| } |
| |
| while ((r = cg_read_pid(f, &pid)) > 0) { |
| |
| if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid) |
| continue; |
| |
| if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid)) |
| continue; |
| |
| if (log_kill) |
| ret_log_kill = log_kill(pid, sig, userdata); |
| |
| /* If we haven't killed this process yet, kill |
| * it */ |
| if (kill(pid, sig) < 0) { |
| if (ret >= 0 && errno != ESRCH) |
| ret = -errno; |
| } else { |
| if (flags & CGROUP_SIGCONT) |
| (void) kill(pid, SIGCONT); |
| |
| if (ret == 0) { |
| if (log_kill) |
| ret = ret_log_kill; |
| else |
| ret = 1; |
| } |
| } |
| |
| done = false; |
| |
| r = set_put(s, PID_TO_PTR(pid)); |
| if (r < 0) { |
| if (ret >= 0) |
| return r; |
| |
| return ret; |
| } |
| } |
| |
| if (r < 0) { |
| if (ret >= 0) |
| return r; |
| |
| return ret; |
| } |
| |
| /* To avoid racing against processes which fork |
| * quicker than we can kill them we repeat this until |
| * no new pids need to be killed. */ |
| |
| } while (!done); |
| |
| return ret; |
| } |
| |
| int cg_kill( |
| const char *controller, |
| const char *path, |
| int sig, |
| CGroupFlags flags, |
| Set *s, |
| cg_kill_log_func_t log_kill, |
| void *userdata) { |
| int r; |
| |
| r = cg_kill_items(controller, path, sig, flags, s, log_kill, userdata, "cgroup.procs"); |
| if (r < 0 || sig != SIGKILL) |
| return r; |
| |
| /* Only in case of killing with SIGKILL and when using cgroupsv2, kill remaining threads manually as |
| a workaround for kernel bug. It was fixed in 5.2-rc5 (c03cd7738a83), backported to 4.19.66 |
| (4340d175b898) and 4.14.138 (feb6b123b7dd). */ |
| r = cg_unified_controller(controller); |
| if (r < 0) |
| return r; |
| if (r == 0) /* doesn't apply to legacy hierarchy */ |
| return 0; |
| |
| return cg_kill_items(controller, path, sig, flags, s, log_kill, userdata, "cgroup.threads"); |
| } |
| |
| int cg_kill_recursive( |
| const char *controller, |
| const char *path, |
| int sig, |
| CGroupFlags flags, |
| Set *s, |
| cg_kill_log_func_t log_kill, |
| void *userdata) { |
| |
| _cleanup_set_free_ Set *allocated_set = NULL; |
| _cleanup_closedir_ DIR *d = NULL; |
| int r, ret; |
| char *fn; |
| |
| assert(path); |
| assert(sig >= 0); |
| |
| if (!s) { |
| s = allocated_set = set_new(NULL); |
| if (!s) |
| return -ENOMEM; |
| } |
| |
| ret = cg_kill(controller, path, sig, flags, s, log_kill, userdata); |
| |
| r = cg_enumerate_subgroups(controller, path, &d); |
| if (r < 0) { |
| if (ret >= 0 && r != -ENOENT) |
| return r; |
| |
| return ret; |
| } |
| |
| while ((r = cg_read_subgroup(d, &fn)) > 0) { |
| _cleanup_free_ char *p = NULL; |
| |
| p = path_join(empty_to_root(path), fn); |
| free(fn); |
| if (!p) |
| return -ENOMEM; |
| |
| r = cg_kill_recursive(controller, p, sig, flags, s, log_kill, userdata); |
| if (r != 0 && ret >= 0) |
| ret = r; |
| } |
| if (ret >= 0 && r < 0) |
| ret = r; |
| |
| if (flags & CGROUP_REMOVE) { |
| r = cg_rmdir(controller, path); |
| if (r < 0 && ret >= 0 && !IN_SET(r, -ENOENT, -EBUSY)) |
| return r; |
| } |
| |
| return ret; |
| } |
| |
| int cg_migrate( |
| const char *cfrom, |
| const char *pfrom, |
| const char *cto, |
| const char *pto, |
| CGroupFlags flags) { |
| |
| bool done = false; |
| _cleanup_set_free_ Set *s = NULL; |
| int r, ret = 0; |
| pid_t my_pid; |
| |
| assert(cfrom); |
| assert(pfrom); |
| assert(cto); |
| assert(pto); |
| |
| s = set_new(NULL); |
| if (!s) |
| return -ENOMEM; |
| |
| my_pid = getpid_cached(); |
| |
| do { |
| _cleanup_fclose_ FILE *f = NULL; |
| pid_t pid = 0; |
| done = true; |
| |
| r = cg_enumerate_processes(cfrom, pfrom, &f); |
| if (r < 0) { |
| if (ret >= 0 && r != -ENOENT) |
| return r; |
| |
| return ret; |
| } |
| |
| while ((r = cg_read_pid(f, &pid)) > 0) { |
| |
| /* This might do weird stuff if we aren't a |
| * single-threaded program. However, we |
| * luckily know we are not */ |
| if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid) |
| continue; |
| |
| if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid)) |
| continue; |
| |
| /* Ignore kernel threads. Since they can only |
| * exist in the root cgroup, we only check for |
| * them there. */ |
| if (cfrom && |
| empty_or_root(pfrom) && |
| is_kernel_thread(pid) > 0) |
| continue; |
| |
| r = cg_attach(cto, pto, pid); |
| if (r < 0) { |
| if (ret >= 0 && r != -ESRCH) |
| ret = r; |
| } else if (ret == 0) |
| ret = 1; |
| |
| done = false; |
| |
| r = set_put(s, PID_TO_PTR(pid)); |
| if (r < 0) { |
| if (ret >= 0) |
| return r; |
| |
| return ret; |
| } |
| } |
| |
| if (r < 0) { |
| if (ret >= 0) |
| return r; |
| |
| return ret; |
| } |
| } while (!done); |
| |
| return ret; |
| } |
| |
| int cg_migrate_recursive( |
| const char *cfrom, |
| const char *pfrom, |
| const char *cto, |
| const char *pto, |
| CGroupFlags flags) { |
| |
| _cleanup_closedir_ DIR *d = NULL; |
| int r, ret = 0; |
| char *fn; |
| |
| assert(cfrom); |
| assert(pfrom); |
| assert(cto); |
| assert(pto); |
| |
| ret = cg_migrate(cfrom, pfrom, cto, pto, flags); |
| |
| r = cg_enumerate_subgroups(cfrom, pfrom, &d); |
| if (r < 0) { |
| if (ret >= 0 && r != -ENOENT) |
| return r; |
| |
| return ret; |
| } |
| |
| while ((r = cg_read_subgroup(d, &fn)) > 0) { |
| _cleanup_free_ char *p = NULL; |
| |
| p = path_join(empty_to_root(pfrom), fn); |
| free(fn); |
| if (!p) |
| return -ENOMEM; |
| |
| r = cg_migrate_recursive(cfrom, p, cto, pto, flags); |
| if (r != 0 && ret >= 0) |
| ret = r; |
| } |
| |
| if (r < 0 && ret >= 0) |
| ret = r; |
| |
| if (flags & CGROUP_REMOVE) { |
| r = cg_rmdir(cfrom, pfrom); |
| if (r < 0 && ret >= 0 && !IN_SET(r, -ENOENT, -EBUSY)) |
| return r; |
| } |
| |
| return ret; |
| } |
| |
| int cg_migrate_recursive_fallback( |
| const char *cfrom, |
| const char *pfrom, |
| const char *cto, |
| const char *pto, |
| CGroupFlags flags) { |
| |
| int r; |
| |
| assert(cfrom); |
| assert(pfrom); |
| assert(cto); |
| assert(pto); |
| |
| r = cg_migrate_recursive(cfrom, pfrom, cto, pto, flags); |
| if (r < 0) { |
| char prefix[strlen(pto) + 1]; |
| |
| /* This didn't work? Then let's try all prefixes of the destination */ |
| |
| PATH_FOREACH_PREFIX(prefix, pto) { |
| int q; |
| |
| q = cg_migrate_recursive(cfrom, pfrom, cto, prefix, flags); |
| if (q >= 0) |
| return q; |
| } |
| } |
| |
| return r; |
| } |
| |
| static const char *controller_to_dirname(const char *controller) { |
| const char *e; |
| |
| assert(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. */ |
| |
| if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| if (cg_hybrid_unified() > 0) |
| controller = SYSTEMD_CGROUP_CONTROLLER_HYBRID; |
| else |
| controller = SYSTEMD_CGROUP_CONTROLLER_LEGACY; |
| } |
| |
| e = startswith(controller, "name="); |
| if (e) |
| return e; |
| |
| return controller; |
| } |
| |
| static int join_path_legacy(const char *controller, const char *path, const char *suffix, char **fs) { |
| const char *dn; |
| char *t = NULL; |
| |
| assert(fs); |
| assert(controller); |
| |
| dn = controller_to_dirname(controller); |
| |
| if (isempty(path) && isempty(suffix)) |
| t = path_join("/sys/fs/cgroup", dn); |
| else if (isempty(path)) |
| t = path_join("/sys/fs/cgroup", dn, suffix); |
| else if (isempty(suffix)) |
| t = path_join("/sys/fs/cgroup", dn, path); |
| else |
| t = path_join("/sys/fs/cgroup", dn, path, suffix); |
| 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 = path_join("/sys/fs/cgroup", suffix); |
| else if (isempty(suffix)) |
| t = path_join("/sys/fs/cgroup", path); |
| else |
| t = path_join("/sys/fs/cgroup", path, suffix); |
| if (!t) |
| return -ENOMEM; |
| |
| *fs = t; |
| return 0; |
| } |
| |
| int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) { |
| int r; |
| |
| assert(fs); |
| |
| if (!controller) { |
| char *t; |
| |
| /* If no controller is specified, we return the path |
| * *below* the controllers, without any prefix. */ |
| |
| if (!path && !suffix) |
| return -EINVAL; |
| |
| if (!suffix) |
| t = strdup(path); |
| else if (!path) |
| t = strdup(suffix); |
| else |
| t = path_join(path, suffix); |
| if (!t) |
| return -ENOMEM; |
| |
| *fs = path_simplify(t, false); |
| return 0; |
| } |
| |
| if (!cg_controller_is_valid(controller)) |
| return -EINVAL; |
| |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| r = join_path_unified(path, suffix, fs); |
| else |
| r = join_path_legacy(controller, path, suffix, fs); |
| if (r < 0) |
| return r; |
| |
| path_simplify(*fs, false); |
| return 0; |
| } |
| |
| static int controller_is_accessible(const char *controller) { |
| int r; |
| |
| assert(controller); |
| |
| /* 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 */ |
| |
| if (!cg_controller_is_valid(controller)) |
| return -EINVAL; |
| |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r > 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) { |
| int r; |
| |
| assert(controller); |
| assert(fs); |
| |
| /* Check if the specified controller is actually accessible */ |
| r = controller_is_accessible(controller); |
| if (r < 0) |
| return r; |
| |
| return cg_get_path(controller, path, suffix, fs); |
| } |
| |
| static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) { |
| assert(path); |
| assert(sb); |
| assert(ftwbuf); |
| |
| if (typeflag != FTW_DP) |
| return 0; |
| |
| if (ftwbuf->level < 1) |
| return 0; |
| |
| (void) rmdir(path); |
| return 0; |
| } |
| |
| int cg_trim(const char *controller, const char *path, bool delete_root) { |
| _cleanup_free_ char *fs = NULL; |
| int r = 0, q; |
| |
| assert(path); |
| |
| r = cg_get_path(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| errno = 0; |
| if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0) { |
| if (errno == ENOENT) |
| r = 0; |
| else |
| r = errno_or_else(EIO); |
| } |
| |
| if (delete_root) { |
| if (rmdir(fs) < 0 && errno != ENOENT) |
| return -errno; |
| } |
| |
| q = cg_hybrid_unified(); |
| if (q < 0) |
| return q; |
| if (q > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| q = cg_trim(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, delete_root); |
| if (q < 0) |
| log_warning_errno(q, "Failed to trim compat systemd cgroup %s: %m", path); |
| } |
| |
| return r; |
| } |
| |
| /* Create a cgroup in the hierarchy of controller. |
| * Returns 0 if the group already existed, 1 on success, negative otherwise. |
| */ |
| int cg_create(const char *controller, const char *path) { |
| _cleanup_free_ char *fs = NULL; |
| int r; |
| |
| r = cg_get_path_and_check(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| r = mkdir_parents(fs, 0755); |
| if (r < 0) |
| return r; |
| |
| r = mkdir_errno_wrapper(fs, 0755); |
| if (r == -EEXIST) |
| return 0; |
| if (r < 0) |
| return r; |
| |
| r = cg_hybrid_unified(); |
| if (r < 0) |
| return r; |
| |
| if (r > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| r = cg_create(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path); |
| if (r < 0) |
| log_warning_errno(r, "Failed to create compat systemd cgroup %s: %m", path); |
| } |
| |
| return 1; |
| } |
| |
| int cg_create_and_attach(const char *controller, const char *path, pid_t pid) { |
| int r, q; |
| |
| assert(pid >= 0); |
| |
| r = cg_create(controller, path); |
| if (r < 0) |
| return r; |
| |
| q = cg_attach(controller, path, pid); |
| if (q < 0) |
| return q; |
| |
| /* This does not remove the cgroup on failure */ |
| return r; |
| } |
| |
| int cg_attach(const char *controller, const char *path, pid_t pid) { |
| _cleanup_free_ char *fs = NULL; |
| char c[DECIMAL_STR_MAX(pid_t) + 2]; |
| int r; |
| |
| assert(path); |
| assert(pid >= 0); |
| |
| r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs); |
| if (r < 0) |
| return r; |
| |
| if (pid == 0) |
| pid = getpid_cached(); |
| |
| xsprintf(c, PID_FMT "\n", pid); |
| |
| r = write_string_file(fs, c, WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return r; |
| |
| r = cg_hybrid_unified(); |
| if (r < 0) |
| return r; |
| |
| if (r > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| r = cg_attach(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, pid); |
| if (r < 0) |
| log_warning_errno(r, "Failed to attach "PID_FMT" to compat systemd cgroup %s: %m", pid, path); |
| } |
| |
| return 0; |
| } |
| |
| int cg_attach_fallback(const char *controller, const char *path, pid_t pid) { |
| int r; |
| |
| assert(controller); |
| assert(path); |
| assert(pid >= 0); |
| |
| r = cg_attach(controller, path, pid); |
| if (r < 0) { |
| char prefix[strlen(path) + 1]; |
| |
| /* This didn't work? Then let's try all prefixes of |
| * the destination */ |
| |
| PATH_FOREACH_PREFIX(prefix, path) { |
| int q; |
| |
| q = cg_attach(controller, prefix, pid); |
| if (q >= 0) |
| return q; |
| } |
| } |
| |
| return r; |
| } |
| |
| int cg_set_access( |
| const char *controller, |
| const char *path, |
| uid_t uid, |
| gid_t gid) { |
| |
| struct Attribute { |
| const char *name; |
| bool fatal; |
| }; |
| |
| /* cgroup v1, aka legacy/non-unified */ |
| static const struct Attribute legacy_attributes[] = { |
| { "cgroup.procs", true }, |
| { "tasks", false }, |
| { "cgroup.clone_children", false }, |
| {}, |
| }; |
| |
| /* cgroup v2, aka unified */ |
| static const struct Attribute unified_attributes[] = { |
| { "cgroup.procs", true }, |
| { "cgroup.subtree_control", true }, |
| { "cgroup.threads", false }, |
| {}, |
| }; |
| |
| static const struct Attribute* const attributes[] = { |
| [false] = legacy_attributes, |
| [true] = unified_attributes, |
| }; |
| |
| _cleanup_free_ char *fs = NULL; |
| const struct Attribute *i; |
| int r, unified; |
| |
| assert(path); |
| |
| if (uid == UID_INVALID && gid == GID_INVALID) |
| return 0; |
| |
| unified = cg_unified_controller(controller); |
| if (unified < 0) |
| return unified; |
| |
| /* Configure access to the cgroup itself */ |
| r = cg_get_path(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| r = chmod_and_chown(fs, 0755, uid, gid); |
| if (r < 0) |
| return r; |
| |
| /* Configure access to the cgroup's attributes */ |
| for (i = attributes[unified]; i->name; i++) { |
| fs = mfree(fs); |
| |
| r = cg_get_path(controller, path, i->name, &fs); |
| if (r < 0) |
| return r; |
| |
| r = chmod_and_chown(fs, 0644, uid, gid); |
| if (r < 0) { |
| if (i->fatal) |
| return r; |
| |
| log_debug_errno(r, "Failed to set access on cgroup %s, ignoring: %m", fs); |
| } |
| } |
| |
| if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) { |
| r = cg_hybrid_unified(); |
| if (r < 0) |
| return r; |
| if (r > 0) { |
| /* Always propagate access mode from unified to legacy controller */ |
| r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, uid, gid); |
| if (r < 0) |
| log_debug_errno(r, "Failed to set access on compatibility systemd cgroup %s, ignoring: %m", path); |
| } |
| } |
| |
| return 0; |
| } |
| |
| int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags) { |
| _cleanup_free_ char *fs = NULL; |
| int r; |
| |
| assert(path); |
| assert(name); |
| assert(value || size <= 0); |
| |
| r = cg_get_path(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| if (setxattr(fs, name, value, size, flags) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size) { |
| _cleanup_free_ char *fs = NULL; |
| ssize_t n; |
| int r; |
| |
| assert(path); |
| assert(name); |
| |
| r = cg_get_path(controller, path, NULL, &fs); |
| if (r < 0) |
| return r; |
| |
| n = getxattr(fs, name, value, size); |
| if (n < 0) |
| return -errno; |
| |
| return (int) n; |
| } |
| |
| int cg_pid_get_path(const char *controller, pid_t pid, char **path) { |
| _cleanup_fclose_ FILE *f = NULL; |
| const char *fs, *controller_str; |
| int unified, r; |
| size_t cs = 0; |
| |
| assert(path); |
| assert(pid >= 0); |
| |
| if (controller) { |
| if (!cg_controller_is_valid(controller)) |
| return -EINVAL; |
| } else |
| controller = SYSTEMD_CGROUP_CONTROLLER; |
| |
| unified = cg_unified_controller(controller); |
| if (unified < 0) |
| return unified; |
| if (unified == 0) { |
| if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) |
| controller_str = SYSTEMD_CGROUP_CONTROLLER_LEGACY; |
| else |
| controller_str = controller; |
| |
| cs = strlen(controller_str); |
| } |
| |
| fs = procfs_file_alloca(pid, "cgroup"); |
| r = fopen_unlocked(fs, "re", &f); |
| if (r == -ENOENT) |
| return -ESRCH; |
| if (r < 0) |
| return r; |
| |
| for (;;) { |
| _cleanup_free_ char *line = NULL; |
| char *e, *p; |
| |
| r = read_line(f, LONG_LINE_MAX, &line); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| |
| if (unified) { |
| e = startswith(line, "0:"); |
| if (!e) |
| continue; |
| |
| 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; |
| |
| l++; |
| e = strchr(l, ':'); |
| if (!e) |
| continue; |
| |
| *e = 0; |
| FOREACH_WORD_SEPARATOR(word, k, l, ",", state) |
| if (k == cs && memcmp(word, controller_str, cs) == 0) { |
| found = true; |
| break; |
| } |
| if (!found) |
| continue; |
| } |
| |
| p = strdup(e + 1); |
| if (!p) |
| return -ENOMEM; |
| |
| /* Truncate suffix indicating the process is a zombie */ |
| e = endswith(p, " (deleted)"); |
| if (e) |
| *e = 0; |
| |
| *path = p; |
| return 0; |
| } |
| |
| return -ENODATA; |
| } |
| |
| int cg_install_release_agent(const char *controller, const char *agent) { |
| _cleanup_free_ char *fs = NULL, *contents = NULL; |
| const char *sc; |
| int r; |
| |
| assert(agent); |
| |
| r = cg_unified_controller(controller); |
| if (r < 0) |
| return r; |
| if (r > 0) /* doesn't apply to unified hierarchy */ |
| return -EOPNOTSUPP; |
| |
| r = cg_get_path(controller, NULL, "release_agent", &fs); |
| if (r < 0) |
| return r; |
| |
| r = read_one_line_file(fs, &contents); |
| if (r < 0) |
| return r; |
| |
| sc = strstrip(contents); |
| if (isempty(sc)) { |
| r = write_string_file(fs, agent, WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return r; |
| } else if (!path_equal(sc, agent)) |
| return -EEXIST; |
| |
| fs = mfree(fs); |
| r = cg_get_path(controller, NULL, "notify_on_release", &fs); |
| if (r < 0) |
| return r; |
| |
| contents = mfree(contents); |
| r = read_one_line_file(fs, &contents); |
| if (r < 0) |
| return r; |
| |
| sc = strstrip(contents); |
| if (streq(sc, "0")) { |
| r = write_string_file(fs, "1", WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return r; |
| |
| return 1; |
| } |
| |
| if (!streq(sc, "1")) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| int cg_uninstall_release_agent(const char *controller) { |
| _cleanup_free_ char *fs = NULL; |
| int r; |
| |
| r = cg_unified_controller(controller); |
| if (r < 0) |
| return r; |
| if (r > 0) /* Doesn't apply to unified hierarchy */ |
| return -EOPNOTSUPP; |
| |
| r = cg_get_path(controller, NULL, "notify_on_release", &fs); |
| if (r < 0) |
| return r; |
| |
| r = write_string_file(fs, "0", WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return r; |
| |
| fs = mfree(fs); |
| |
| r = cg_get_path(controller, NULL, "release_agent", &fs); |
| if (r < 0) |
| return r; |
| |
| r = write_string_file(fs, "", WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return r; |
| |
| return 0; |
| } |
| |
| int cg_is_empty(const char *controller, const char *path) { |
| _cleanup_fclose_ FILE *f = NULL; |
| pid_t pid; |
| int r; |
| |
| assert(path); |
| |
| r = cg_enumerate_processes(controller, path, &f); |
| if (r == -ENOENT) |
| return true; |
| if (r < 0) |
| return r; |
| |
| r = cg_read_pid(f, &pid); |
| if (r < 0) |
| return r; |
| |
| return r == 0; |
| } |
| |
| int cg_is_empty_recursive(const char *controller, const char *path) { |
| int r; |
| |
| assert(path); |
| |
| /* The root cgroup is always populated */ |
| if (controller && empty_or_root(path)) |
| return false; |
| |
| r = cg_unified_controller(controller); |
| if (r < 0) |
| return r; |
| if (r > 0) { |
| _cleanup_free_ char *t = NULL; |
| |
| /* On the unified hierarchy we can check empty state |
| * via the "populated" attribute of "cgroup.events". */ |
| |
| r = cg_read_event(controller, path, "populated", &t); |
| if (r == -ENOENT) |
| return true; |
| if (r < 0) |
| return r; |
| |
| return streq(t, "0"); |
| } else { |
| _cleanup_closedir_ DIR *d = NULL; |
| char *fn; |
| |
| r = cg_is_empty(controller, path); |
| if (r <= 0) |
| return r; |
| |
| r = cg_enumerate_subgroups(controller, path, &d); |
| if (r == -ENOENT) |
| return true; |
| if (r < 0) |
| return r; |
| |
| while ((r = cg_read_subgroup(d, &fn)) > 0) { |
| _cleanup_free_ char *p = NULL; |
| |
| p = path_join(path, fn); |
| 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) { |
| char *t = NULL, *u = NULL; |
| const char *e; |
| |
| assert(spec); |
| |
| if (*spec == '/') { |
| if (!path_is_normalized(spec)) |
| return -EINVAL; |
| |
| if (path) { |
| t = strdup(spec); |
| if (!t) |
| return -ENOMEM; |
| |
| *path = path_simplify(t, false); |
| } |
| |
| if (controller) |
| *controller = NULL; |
| |
| return 0; |
| } |
| |
| e = strchr(spec, ':'); |
| if (!e) { |
| if (!cg_controller_is_valid(spec)) |
| return -EINVAL; |
| |
| if (controller) { |
| t = strdup(spec); |
| if (!t) |
| return -ENOMEM; |
| |
| *controller = t; |
| } |
| |
| if (path) |
| *path = NULL; |
| |
| return 0; |
| } |
| |
| t = strndup(spec, e-spec); |
| if (!t) |
| return -ENOMEM; |
| if (!cg_controller_is_valid(t)) { |
| free(t); |
| return -EINVAL; |
| } |
| |
| if (isempty(e+1)) |
| u = NULL; |
| else { |
| u = strdup(e+1); |
| if (!u) { |
| free(t); |
| return -ENOMEM; |
| } |
| |
| if (!path_is_normalized(u) || |
| !path_is_absolute(u)) { |
| free(t); |
| free(u); |
| return -EINVAL; |
| } |
| |
| path_simplify(u, false); |
| } |
| |
| if (controller) |
| *controller = t; |
| else |
| free(t); |
| |
| if (path) |
| *path = u; |
| else |
| free(u); |
| |
| return 0; |
| } |
| |
| int cg_mangle_path(const char *path, char **result) { |
| _cleanup_free_ char *c = NULL, *p = NULL; |
| char *t; |
| int r; |
| |
| assert(path); |
| assert(result); |
| |
| /* First, check if it already is a filesystem path */ |
| if (path_startswith(path, "/sys/fs/cgroup")) { |
| |
| t = strdup(path); |
| if (!t) |
| return -ENOMEM; |
| |
| *result = path_simplify(t, false); |
| return 0; |
| } |
| |
| /* Otherwise, treat it as cg spec */ |
| r = cg_split_spec(path, &c, &p); |
| if (r < 0) |
| return r; |
| |
| return cg_get_path(c ?: SYSTEMD_CGROUP_CONTROLLER, p ?: "/", NULL, result); |
| } |
| |
| int cg_get_root_path(char **path) { |
| char *p, *e; |
| int r; |
| |
| assert(path); |
| |
| r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p); |
| if (r < 0) |
| return r; |
| |
| 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; |
| |
| *path = p; |
| return 0; |
| } |
| |
| int cg_shift_path(const char *cgroup, const char *root, const char **shifted) { |
| _cleanup_free_ char *rt = NULL; |
| char *p; |
| int r; |
| |
| assert(cgroup); |
| assert(shifted); |
| |
| if (!root) { |
| /* If the root was specified let's use that, otherwise |
| * let's determine it from PID 1 */ |
| |
| r = cg_get_root_path(&rt); |
| if (r < 0) |
| return r; |
| |
| root = rt; |
| } |
| |
| p = path_startswith(cgroup, root); |
| if (p && p > cgroup) |
| *shifted = p - 1; |
| else |
| *shifted = cgroup; |
| |
| return 0; |
| } |
| |
| int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) { |
| _cleanup_free_ char *raw = NULL; |
| const char *c; |
| int r; |
| |
| assert(pid >= 0); |
| assert(cgroup); |
| |
| r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw); |
| if (r < 0) |
| return r; |
| |
| r = cg_shift_path(raw, root, &c); |
| if (r < 0) |
| return r; |
| |
| if (c == raw) |
| *cgroup = TAKE_PTR(raw); |
| else { |
| char *n; |
| |
| n = strdup(c); |
| if (!n) |
| return -ENOMEM; |
| |
| *cgroup = n; |
| } |
| |
| return 0; |
| } |
| |
| int cg_path_decode_unit(const char *cgroup, char **unit) { |
| char *c, *s; |
| size_t n; |
| |
| assert(cgroup); |
| assert(unit); |
| |
| n = strcspn(cgroup, "/"); |
| if (n < 3) |
| return -ENXIO; |
| |
| c = strndupa(cgroup, n); |
| c = cg_unescape(c); |
| |
| if (!unit_name_is_valid(c, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) |
| return -ENXIO; |
| |
| s = strdup(c); |
| if (!s) |
| return -ENOMEM; |
| |
| *unit = s; |
| return 0; |
| } |
| |
| static bool valid_slice_name(const char *p, size_t n) { |
| |
| if (!p) |
| return false; |
| |
| if (n < STRLEN("x.slice")) |
| return false; |
| |
| if (memcmp(p + n - 6, ".slice", 6) == 0) { |
| char buf[n+1], *c; |
| |
| memcpy(buf, p, n); |
| buf[n] = 0; |
| |
| c = cg_unescape(buf); |
| |
| return unit_name_is_valid(c, UNIT_NAME_PLAIN); |
| } |
| |
| return false; |
| } |
| |
| static const char *skip_slices(const char *p) { |
| assert(p); |
| |
| /* Skips over all slice assignments */ |
| |
| for (;;) { |
| size_t n; |
| |
| p += strspn(p, "/"); |
| |
| n = strcspn(p, "/"); |
| if (!valid_slice_name(p, n)) |
| return p; |
| |
| p += n; |
| } |
| } |
| |
| int cg_path_get_unit(const char *path, char **ret) { |
| const char *e; |
| char *unit; |
| int r; |
| |
| assert(path); |
| assert(ret); |
| |
| e = skip_slices(path); |
| |
| r = cg_path_decode_unit(e, &unit); |
| if (r < 0) |
| return r; |
| |
| /* We skipped over the slices, don't accept any now */ |
| if (endswith(unit, ".slice")) { |
| free(unit); |
| return -ENXIO; |
| } |
| |
| *ret = unit; |
| return 0; |
| } |
| |
| int cg_pid_get_unit(pid_t pid, char **unit) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| assert(unit); |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_unit(cgroup, unit); |
| } |
| |
| /** |
| * Skip session-*.scope, but require it to be there. |
| */ |
| static const char *skip_session(const char *p) { |
| size_t n; |
| |
| if (isempty(p)) |
| return NULL; |
| |
| p += strspn(p, "/"); |
| |
| n = strcspn(p, "/"); |
| if (n < STRLEN("session-x.scope")) |
| return NULL; |
| |
| if (memcmp(p, "session-", 8) == 0 && memcmp(p + n - 6, ".scope", 6) == 0) { |
| char buf[n - 8 - 6 + 1]; |
| |
| memcpy(buf, p + 8, n - 8 - 6); |
| buf[n - 8 - 6] = 0; |
| |
| /* Note that session scopes never need unescaping, |
| * since they cannot conflict with the kernel's own |
| * names, hence we don't need to call cg_unescape() |
| * here. */ |
| |
| if (!session_id_valid(buf)) |
| return false; |
| |
| p += n; |
| p += strspn(p, "/"); |
| return p; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * Skip user@*.service, but require it to be there. |
| */ |
| static const char *skip_user_manager(const char *p) { |
| size_t n; |
| |
| if (isempty(p)) |
| return NULL; |
| |
| p += strspn(p, "/"); |
| |
| n = strcspn(p, "/"); |
| if (n < STRLEN("user@x.service")) |
| return NULL; |
| |
| if (memcmp(p, "user@", 5) == 0 && memcmp(p + n - 8, ".service", 8) == 0) { |
| char buf[n - 5 - 8 + 1]; |
| |
| memcpy(buf, p + 5, n - 5 - 8); |
| buf[n - 5 - 8] = 0; |
| |
| /* Note that user manager services never need unescaping, |
| * since they cannot conflict with the kernel's own |
| * names, hence we don't need to call cg_unescape() |
| * here. */ |
| |
| if (parse_uid(buf, NULL) < 0) |
| return NULL; |
| |
| p += n; |
| p += strspn(p, "/"); |
| |
| return p; |
| } |
| |
| return NULL; |
| } |
| |
| static const char *skip_user_prefix(const char *path) { |
| const char *e, *t; |
| |
| assert(path); |
| |
| /* Skip slices, if there are any */ |
| e = skip_slices(path); |
| |
| /* Skip the user manager, if it's in the path now... */ |
| t = skip_user_manager(e); |
| if (t) |
| return t; |
| |
| /* Alternatively skip the user session if it is in the path... */ |
| return skip_session(e); |
| } |
| |
| int cg_path_get_user_unit(const char *path, char **ret) { |
| const char *t; |
| |
| assert(path); |
| assert(ret); |
| |
| t = skip_user_prefix(path); |
| if (!t) |
| return -ENXIO; |
| |
| /* And from here on it looks pretty much the same as for a system unit, hence let's use the same |
| * parser. */ |
| return cg_path_get_unit(t, ret); |
| } |
| |
| int cg_pid_get_user_unit(pid_t pid, char **unit) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| assert(unit); |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_user_unit(cgroup, unit); |
| } |
| |
| int cg_path_get_machine_name(const char *path, char **machine) { |
| _cleanup_free_ char *u = NULL; |
| const char *sl; |
| int r; |
| |
| r = cg_path_get_unit(path, &u); |
| if (r < 0) |
| return r; |
| |
| sl = strjoina("/run/systemd/machines/unit:", u); |
| return readlink_malloc(sl, machine); |
| } |
| |
| int cg_pid_get_machine_name(pid_t pid, char **machine) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| assert(machine); |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_machine_name(cgroup, machine); |
| } |
| |
| int cg_path_get_session(const char *path, char **session) { |
| _cleanup_free_ char *unit = NULL; |
| char *start, *end; |
| int r; |
| |
| assert(path); |
| |
| r = cg_path_get_unit(path, &unit); |
| if (r < 0) |
| return r; |
| |
| start = startswith(unit, "session-"); |
| if (!start) |
| return -ENXIO; |
| end = endswith(start, ".scope"); |
| if (!end) |
| return -ENXIO; |
| |
| *end = 0; |
| if (!session_id_valid(start)) |
| return -ENXIO; |
| |
| if (session) { |
| char *rr; |
| |
| rr = strdup(start); |
| if (!rr) |
| return -ENOMEM; |
| |
| *session = rr; |
| } |
| |
| return 0; |
| } |
| |
| int cg_pid_get_session(pid_t pid, char **session) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_session(cgroup, session); |
| } |
| |
| int cg_path_get_owner_uid(const char *path, uid_t *uid) { |
| _cleanup_free_ char *slice = NULL; |
| char *start, *end; |
| int r; |
| |
| assert(path); |
| |
| r = cg_path_get_slice(path, &slice); |
| if (r < 0) |
| return r; |
| |
| start = startswith(slice, "user-"); |
| if (!start) |
| return -ENXIO; |
| end = endswith(start, ".slice"); |
| if (!end) |
| return -ENXIO; |
| |
| *end = 0; |
| if (parse_uid(start, uid) < 0) |
| return -ENXIO; |
| |
| return 0; |
| } |
| |
| int cg_pid_get_owner_uid(pid_t pid, uid_t *uid) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_owner_uid(cgroup, uid); |
| } |
| |
| int cg_path_get_slice(const char *p, char **slice) { |
| const char *e = NULL; |
| |
| assert(p); |
| assert(slice); |
| |
| /* Finds the right-most slice unit from the beginning, but |
| * stops before we come to the first non-slice unit. */ |
| |
| for (;;) { |
| size_t n; |
| |
| p += strspn(p, "/"); |
| |
| n = strcspn(p, "/"); |
| if (!valid_slice_name(p, n)) { |
| |
| if (!e) { |
| char *s; |
| |
| s = strdup(SPECIAL_ROOT_SLICE); |
| if (!s) |
| return -ENOMEM; |
| |
| *slice = s; |
| return 0; |
| } |
| |
| return cg_path_decode_unit(e, slice); |
| } |
| |
| e = p; |
| p += n; |
| } |
| } |
| |
| int cg_pid_get_slice(pid_t pid, char **slice) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| assert(slice); |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_slice(cgroup, slice); |
| } |
| |
| int cg_path_get_user_slice(const char *p, char **slice) { |
| const char *t; |
| assert(p); |
| assert(slice); |
| |
| t = skip_user_prefix(p); |
| if (!t) |
| return -ENXIO; |
| |
| /* And now it looks pretty much the same as for a system |
| * slice, so let's just use the same parser from here on. */ |
| return cg_path_get_slice(t, slice); |
| } |
| |
| int cg_pid_get_user_slice(pid_t pid, char **slice) { |
| _cleanup_free_ char *cgroup = NULL; |
| int r; |
| |
| assert(slice); |
| |
| r = cg_pid_get_path_shifted(pid, NULL, &cgroup); |
| if (r < 0) |
| return r; |
| |
| return cg_path_get_user_slice(cgroup, slice); |
| } |
| |
| char *cg_escape(const char *p) { |
| bool need_prefix = false; |
| |
| /* This implements very minimal escaping for names to be used |
| * as file names in the cgroup tree: any name which might |
| * conflict with a kernel name or is prefixed with '_' is |
| * prefixed with a '_'. That way, when reading cgroup names it |
| * is sufficient to remove a single prefixing underscore if |
| * there is one. */ |
| |
| /* The return value of this function (unlike cg_unescape()) |
| * needs free()! */ |
| |
| if (IN_SET(p[0], 0, '_', '.') || |
| STR_IN_SET(p, "notify_on_release", "release_agent", "tasks") || |
| startswith(p, "cgroup.")) |
| need_prefix = true; |
| else { |
| const char *dot; |
| |
| dot = strrchr(p, '.'); |
| if (dot) { |
| CGroupController c; |
| size_t l = dot - p; |
| |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| const char *n; |
| |
| n = cgroup_controller_to_string(c); |
| |
| if (l != strlen(n)) |
| continue; |
| |
| if (memcmp(p, n, l) != 0) |
| continue; |
| |
| need_prefix = true; |
| break; |
| } |
| } |
| } |
| |
| if (need_prefix) |
| return strjoin("_", p); |
| |
| return strdup(p); |
| } |
| |
| char *cg_unescape(const char *p) { |
| assert(p); |
| |
| /* The return value of this function (unlike cg_escape()) |
| * doesn't need free()! */ |
| |
| if (p[0] == '_') |
| return (char*) p+1; |
| |
| return (char*) p; |
| } |
| |
| #define CONTROLLER_VALID \ |
| DIGITS LETTERS \ |
| "_" |
| |
| bool cg_controller_is_valid(const char *p) { |
| const char *t, *s; |
| |
| if (!p) |
| return false; |
| |
| if (streq(p, SYSTEMD_CGROUP_CONTROLLER)) |
| return true; |
| |
| s = startswith(p, "name="); |
| if (s) |
| p = s; |
| |
| if (IN_SET(*p, 0, '_')) |
| return false; |
| |
| for (t = p; *t; t++) |
| if (!strchr(CONTROLLER_VALID, *t)) |
| return false; |
| |
| if (t - p > FILENAME_MAX) |
| return false; |
| |
| return true; |
| } |
| |
| int cg_slice_to_path(const char *unit, char **ret) { |
| _cleanup_free_ char *p = NULL, *s = NULL, *e = NULL; |
| const char *dash; |
| int r; |
| |
| assert(unit); |
| assert(ret); |
| |
| if (streq(unit, SPECIAL_ROOT_SLICE)) { |
| char *x; |
| |
| x = strdup(""); |
| if (!x) |
| return -ENOMEM; |
| *ret = x; |
| return 0; |
| } |
| |
| if (!unit_name_is_valid(unit, UNIT_NAME_PLAIN)) |
| return -EINVAL; |
| |
| if (!endswith(unit, ".slice")) |
| return -EINVAL; |
| |
| r = unit_name_to_prefix(unit, &p); |
| if (r < 0) |
| return r; |
| |
| dash = strchr(p, '-'); |
| |
| /* Don't allow initial dashes */ |
| if (dash == p) |
| return -EINVAL; |
| |
| while (dash) { |
| _cleanup_free_ char *escaped = NULL; |
| char n[dash - p + sizeof(".slice")]; |
| |
| #if HAS_FEATURE_MEMORY_SANITIZER |
| /* msan doesn't instrument stpncpy, so it thinks |
| * n is later used uninitialized: |
| * https://github.com/google/sanitizers/issues/926 |
| */ |
| zero(n); |
| #endif |
| |
| /* Don't allow trailing or double dashes */ |
| if (IN_SET(dash[1], 0, '-')) |
| return -EINVAL; |
| |
| strcpy(stpncpy(n, p, dash - p), ".slice"); |
| if (!unit_name_is_valid(n, UNIT_NAME_PLAIN)) |
| return -EINVAL; |
| |
| escaped = cg_escape(n); |
| if (!escaped) |
| return -ENOMEM; |
| |
| if (!strextend(&s, escaped, "/", NULL)) |
| return -ENOMEM; |
| |
| dash = strchr(dash+1, '-'); |
| } |
| |
| e = cg_escape(unit); |
| if (!e) |
| return -ENOMEM; |
| |
| if (!strextend(&s, e, NULL)) |
| return -ENOMEM; |
| |
| *ret = TAKE_PTR(s); |
| |
| return 0; |
| } |
| |
| int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) { |
| _cleanup_free_ char *p = NULL; |
| int r; |
| |
| r = cg_get_path(controller, path, attribute, &p); |
| if (r < 0) |
| return r; |
| |
| return write_string_file(p, value, WRITE_STRING_FILE_DISABLE_BUFFER); |
| } |
| |
| int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) { |
| _cleanup_free_ char *p = NULL; |
| int r; |
| |
| r = cg_get_path(controller, path, attribute, &p); |
| if (r < 0) |
| return r; |
| |
| return read_one_line_file(p, ret); |
| } |
| |
| int cg_get_keyed_attribute( |
| const char *controller, |
| const char *path, |
| const char *attribute, |
| char **keys, |
| char **ret_values) { |
| |
| _cleanup_free_ char *filename = NULL, *contents = NULL; |
| const char *p; |
| size_t n, i, n_done = 0; |
| char **v; |
| int r; |
| |
| /* Reads one or more fields of a cgroup v2 keyed attribute file. The 'keys' parameter should be an strv with |
| * all keys to retrieve. The 'ret_values' parameter should be passed as string size with the same number of |
| * entries as 'keys'. On success each entry will be set to the value of the matching key. |
| * |
| * If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. */ |
| |
| r = cg_get_path(controller, path, attribute, &filename); |
| if (r < 0) |
| return r; |
| |
| r = read_full_file(filename, &contents, NULL); |
| if (r < 0) |
| return r; |
| |
| n = strv_length(keys); |
| if (n == 0) /* No keys to retrieve? That's easy, we are done then */ |
| return 0; |
| |
| /* Let's build this up in a temporary array for now in order not to clobber the return parameter on failure */ |
| v = newa0(char*, n); |
| |
| for (p = contents; *p;) { |
| const char *w = NULL; |
| |
| for (i = 0; i < n; i++) |
| if (!v[i]) { |
| w = first_word(p, keys[i]); |
| if (w) |
| break; |
| } |
| |
| if (w) { |
| size_t l; |
| |
| l = strcspn(w, NEWLINE); |
| v[i] = strndup(w, l); |
| if (!v[i]) { |
| r = -ENOMEM; |
| goto fail; |
| } |
| |
| n_done++; |
| if (n_done >= n) |
| goto done; |
| |
| p = w + l; |
| } else |
| p += strcspn(p, NEWLINE); |
| |
| p += strspn(p, NEWLINE); |
| } |
| |
| r = -ENXIO; |
| |
| fail: |
| for (i = 0; i < n; i++) |
| free(v[i]); |
| |
| return r; |
| |
| done: |
| memcpy(ret_values, v, sizeof(char*) * n); |
| return 0; |
| |
| } |
| |
| int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) { |
| CGroupController c; |
| CGroupMask done; |
| bool created; |
| int r; |
| |
| /* This one will create a cgroup in our private tree, but also |
| * duplicate it in the trees specified in mask, and remove it |
| * in all others. |
| * |
| * Returns 0 if the group already existed in the systemd hierarchy, |
| * 1 on success, negative otherwise. |
| */ |
| |
| /* First create the cgroup in our own hierarchy. */ |
| r = cg_create(SYSTEMD_CGROUP_CONTROLLER, path); |
| if (r < 0) |
| return r; |
| created = r; |
| |
| /* If we are in the unified hierarchy, we are done now */ |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| return created; |
| |
| supported &= CGROUP_MASK_V1; |
| mask = CGROUP_MASK_EXTEND_JOINED(mask); |
| done = 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; |
| |
| if (!FLAGS_SET(supported, bit)) |
| continue; |
| |
| if (FLAGS_SET(done, bit)) |
| continue; |
| |
| n = cgroup_controller_to_string(c); |
| if (FLAGS_SET(mask, bit)) |
| (void) cg_create(n, path); |
| else |
| (void) cg_trim(n, path, true); |
| |
| done |= CGROUP_MASK_EXTEND_JOINED(bit); |
| } |
| |
| return created; |
| } |
| |
| int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) { |
| CGroupController c; |
| CGroupMask done; |
| int r; |
| |
| r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid); |
| if (r < 0) |
| return r; |
| |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| return 0; |
| |
| supported &= CGROUP_MASK_V1; |
| done = 0; |
| |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); |
| const char *p = NULL; |
| |
| if (!FLAGS_SET(supported, bit)) |
| continue; |
| |
| if (FLAGS_SET(done, bit)) |
| continue; |
| |
| if (path_callback) |
| p = path_callback(bit, userdata); |
| if (!p) |
| p = path; |
| |
| (void) cg_attach_fallback(cgroup_controller_to_string(c), p, pid); |
| done |= CGROUP_MASK_EXTEND_JOINED(bit); |
| } |
| |
| return 0; |
| } |
| |
| 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; |
| |
| SET_FOREACH(pidp, pids, i) { |
| pid_t pid = PTR_TO_PID(pidp); |
| int q; |
| |
| q = cg_attach_everywhere(supported, path, pid, path_callback, userdata); |
| if (q < 0 && r >= 0) |
| r = q; |
| } |
| |
| return r; |
| } |
| |
| int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) { |
| CGroupController c; |
| CGroupMask done; |
| int r = 0, q; |
| |
| if (!path_equal(from, to)) { |
| r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, CGROUP_REMOVE); |
| if (r < 0) |
| return r; |
| } |
| |
| q = cg_all_unified(); |
| if (q < 0) |
| return q; |
| if (q > 0) |
| return r; |
| |
| supported &= CGROUP_MASK_V1; |
| done = 0; |
| |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); |
| const char *p = NULL; |
| |
| if (!FLAGS_SET(supported, bit)) |
| continue; |
| |
| if (FLAGS_SET(done, bit)) |
| continue; |
| |
| if (to_callback) |
| p = to_callback(bit, userdata); |
| if (!p) |
| p = to; |
| |
| (void) cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, cgroup_controller_to_string(c), p, 0); |
| done |= CGROUP_MASK_EXTEND_JOINED(bit); |
| } |
| |
| return r; |
| } |
| |
| int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) { |
| CGroupController c; |
| CGroupMask done; |
| int r, q; |
| |
| r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root); |
| if (r < 0) |
| return r; |
| |
| q = cg_all_unified(); |
| if (q < 0) |
| return q; |
| if (q > 0) |
| return r; |
| |
| supported &= CGROUP_MASK_V1; |
| done = 0; |
| |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); |
| |
| if (!FLAGS_SET(supported, bit)) |
| continue; |
| |
| if (FLAGS_SET(done, bit)) |
| continue; |
| |
| (void) cg_trim(cgroup_controller_to_string(c), path, delete_root); |
| done |= CGROUP_MASK_EXTEND_JOINED(bit); |
| } |
| |
| return r; |
| } |
| |
| int cg_mask_to_string(CGroupMask mask, char **ret) { |
| _cleanup_free_ char *s = NULL; |
| size_t n = 0, allocated = 0; |
| bool space = false; |
| CGroupController c; |
| |
| assert(ret); |
| |
| if (mask == 0) { |
| *ret = NULL; |
| return 0; |
| } |
| |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| const char *k; |
| size_t l; |
| |
| if (!FLAGS_SET(mask, CGROUP_CONTROLLER_TO_MASK(c))) |
| continue; |
| |
| k = cgroup_controller_to_string(c); |
| l = strlen(k); |
| |
| if (!GREEDY_REALLOC(s, allocated, n + space + l + 1)) |
| return -ENOMEM; |
| |
| if (space) |
| s[n] = ' '; |
| memcpy(s + n + space, k, l); |
| n += space + l; |
| |
| space = true; |
| } |
| |
| assert(s); |
| |
| s[n] = 0; |
| *ret = TAKE_PTR(s); |
| |
| return 0; |
| } |
| |
| int cg_mask_from_string(const char *value, CGroupMask *ret) { |
| CGroupMask m = 0; |
| |
| assert(ret); |
| assert(value); |
| |
| for (;;) { |
| _cleanup_free_ char *n = NULL; |
| CGroupController v; |
| int r; |
| |
| r = extract_first_word(&value, &n, NULL, 0); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| |
| v = cgroup_controller_from_string(n); |
| if (v < 0) |
| continue; |
| |
| m |= CGROUP_CONTROLLER_TO_MASK(v); |
| } |
| |
| *ret = m; |
| return 0; |
| } |
| |
| int cg_mask_supported(CGroupMask *ret) { |
| CGroupMask mask; |
| int r; |
| |
| /* Determines the mask of supported cgroup controllers. Only includes controllers we can make sense of and that |
| * are actually accessible. Only covers real controllers, i.e. not the CGROUP_CONTROLLER_BPF_xyz |
| * pseudo-controllers. */ |
| |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r > 0) { |
| _cleanup_free_ char *root = NULL, *controllers = NULL, *path = NULL; |
| |
| /* In the unified hierarchy we can read the supported |
| * and accessible controllers from a the top-level |
| * cgroup attribute */ |
| |
| r = cg_get_root_path(&root); |
| if (r < 0) |
| return r; |
| |
| r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, "cgroup.controllers", &path); |
| if (r < 0) |
| return r; |
| |
| r = read_one_line_file(path, &controllers); |
| if (r < 0) |
| return r; |
| |
| r = cg_mask_from_string(controllers, &mask); |
| if (r < 0) |
| return r; |
| |
| /* Currently, we support the cpu, memory, io and pids controller in the unified hierarchy, mask |
| * everything else off. */ |
| mask &= CGROUP_MASK_V2; |
| |
| } else { |
| CGroupController c; |
| |
| /* In the legacy hierarchy, we check which hierarchies are mounted. */ |
| |
| mask = 0; |
| for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { |
| CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); |
| const char *n; |
| |
| if (!FLAGS_SET(CGROUP_MASK_V1, bit)) |
| continue; |
| |
| n = cgroup_controller_to_string(c); |
| if (controller_is_accessible(n) >= 0) |
| mask |= bit; |
| } |
| } |
| |
| *ret = mask; |
| return 0; |
| } |
| |
| int cg_kernel_controllers(Set **ret) { |
| _cleanup_set_free_free_ Set *controllers = NULL; |
| _cleanup_fclose_ FILE *f = NULL; |
| int r; |
| |
| assert(ret); |
| |
| /* Determines the full list of kernel-known controllers. Might include controllers we don't actually support |
| * and controllers that aren't currently accessible (because not mounted). This does not include "name=" |
| * pseudo-controllers. */ |
| |
| controllers = set_new(&string_hash_ops); |
| if (!controllers) |
| return -ENOMEM; |
| |
| r = fopen_unlocked("/proc/cgroups", "re", &f); |
| if (r == -ENOENT) { |
| *ret = NULL; |
| return 0; |
| } |
| if (r < 0) |
| return r; |
| |
| /* Ignore the header line */ |
| (void) read_line(f, (size_t) -1, NULL); |
| |
| for (;;) { |
| char *controller; |
| int enabled = 0; |
| |
| errno = 0; |
| if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) { |
| |
| if (feof(f)) |
| break; |
| |
| if (ferror(f)) |
| return errno_or_else(EIO); |
| |
| return -EBADMSG; |
| } |
| |
| if (!enabled) { |
| free(controller); |
| continue; |
| } |
| |
| if (!cg_controller_is_valid(controller)) { |
| free(controller); |
| return -EBADMSG; |
| } |
| |
| r = set_consume(controllers, controller); |
| if (r < 0) |
| return r; |
| } |
| |
| *ret = TAKE_PTR(controllers); |
| |
| return 0; |
| } |
| |
| static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN; |
| |
| /* The hybrid mode was initially implemented in v232 and simply mounted cgroup2 on /sys/fs/cgroup/systemd. This |
| * unfortunately broke other tools (such as docker) which expected the v1 "name=systemd" hierarchy on |
| * /sys/fs/cgroup/systemd. From v233 and on, the hybrid mode mountnbs v2 on /sys/fs/cgroup/unified and maintains |
| * "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility with other tools. |
| * |
| * To keep live upgrade working, we detect and support v232 layout. When v232 layout is detected, to keep cgroup v2 |
| * process management but disable the compat dual layout, we return %true on |
| * cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) and %false on cg_hybrid_unified(). |
| */ |
| static thread_local bool unified_systemd_v232; |
| |
| static int cg_unified_update(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 >= CGROUP_UNIFIED_NONE) |
| return 0; |
| |
| if (statfs("/sys/fs/cgroup/", &fs) < 0) |
| return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/\") failed: %m"); |
| |
| if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) { |
| log_debug("Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy"); |
| unified_cache = CGROUP_UNIFIED_ALL; |
| } else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC)) { |
| if (statfs("/sys/fs/cgroup/unified/", &fs) == 0 && |
| F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) { |
| log_debug("Found cgroup2 on /sys/fs/cgroup/unified, unified hierarchy for systemd controller"); |
| unified_cache = CGROUP_UNIFIED_SYSTEMD; |
| unified_systemd_v232 = false; |
| } else { |
| if (statfs("/sys/fs/cgroup/systemd/", &fs) < 0) |
| return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/systemd\" failed: %m"); |
| |
| if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) { |
| log_debug("Found cgroup2 on /sys/fs/cgroup/systemd, unified hierarchy for systemd controller (v232 variant)"); |
| unified_cache = CGROUP_UNIFIED_SYSTEMD; |
| unified_systemd_v232 = true; |
| } else if (F_TYPE_EQUAL(fs.f_type, CGROUP_SUPER_MAGIC)) { |
| log_debug("Found cgroup on /sys/fs/cgroup/systemd, legacy hierarchy"); |
| unified_cache = CGROUP_UNIFIED_NONE; |
| } else { |
| log_debug("Unexpected filesystem type %llx mounted on /sys/fs/cgroup/systemd, assuming legacy hierarchy", |
| (unsigned long long) fs.f_type); |
| unified_cache = CGROUP_UNIFIED_NONE; |
| } |
| } |
| } else |
| return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM), |
| "Unknown filesystem type %llx mounted on /sys/fs/cgroup.", |
| (unsigned long long)fs.f_type); |
| |
| return 0; |
| } |
| |
| int cg_unified_controller(const char *controller) { |
| int r; |
| |
| r = cg_unified_update(); |
| if (r < 0) |
| return r; |
| |
| if (unified_cache == CGROUP_UNIFIED_NONE) |
| return false; |
| |
| if (unified_cache >= CGROUP_UNIFIED_ALL) |
| return true; |
| |
| return streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER); |
| } |
| |
| int cg_all_unified(void) { |
| int r; |
| |
| r = cg_unified_update(); |
| if (r < 0) |
| return r; |
| |
| return unified_cache >= CGROUP_UNIFIED_ALL; |
| } |
| |
| int cg_hybrid_unified(void) { |
| int r; |
| |
| r = cg_unified_update(); |
| if (r < 0) |
| return r; |
| |
| return unified_cache == CGROUP_UNIFIED_SYSTEMD && !unified_systemd_v232; |
| } |
| |
| int cg_unified_flush(void) { |
| unified_cache = CGROUP_UNIFIED_UNKNOWN; |
| |
| return cg_unified_update(); |
| } |
| |
| int cg_enable_everywhere( |
| CGroupMask supported, |
| CGroupMask mask, |
| const char *p, |
| CGroupMask *ret_result_mask) { |
| |
| _cleanup_fclose_ FILE *f = NULL; |
| _cleanup_free_ char *fs = NULL; |
| CGroupController c; |
| CGroupMask ret = 0; |
| int r; |
| |
| assert(p); |
| |
| if (supported == 0) { |
| if (ret_result_mask) |
| *ret_result_mask = 0; |
| return 0; |
| } |
| |
| r = cg_all_unified(); |
| if (r < 0) |
| return r; |
| if (r == 0) { |
| /* On the legacy hierarchy there's no concept of "enabling" controllers in cgroups defined. Let's claim |
| * complete success right away. (If you wonder why we return the full mask here, rather than zero: the |
| * caller tends to use the returned mask later on to compare if all controllers where properly joined, |
| * and if not requeues realization. This use is the primary purpose of the return value, hence let's |
| * minimize surprises here and reduce triggers for re-realization by always saying we fully |
| * succeeded.) */ |
| if (ret_result_mask) |
| *ret_result_mask = mask & supported & CGROUP_MASK_V2; /* If you wonder why we mask this with |
| * CGROUP_MASK_V2: The 'supported' mask |
| * might contain pure-V1 or BPF |
| * controllers, and we never want to |
| * claim that we could enable those with |
| * cgroup.subtree_control */ |
| 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 (!FLAGS_SET(CGROUP_MASK_V2, bit)) |
| continue; |
| |
| if (!FLAGS_SET(supported, bit)) |
| continue; |
| |
| n = cgroup_controller_to_string(c); |
| { |
| char s[1 + strlen(n) + 1]; |
| |
| s[0] = FLAGS_SET(mask, bit) ? '+' : '-'; |
| strcpy(s + 1, n); |
| |
| if (!f) { |
| f = fopen(fs, "we"); |
| if (!f) |
| return log_debug_errno(errno, "Failed to open cgroup.subtree_control file of %s: %m", p); |
| } |
| |
| r = write_string_stream(f, s, WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) { |
| log_debug_errno(r, "Failed to %s controller %s for %s (%s): %m", |
| FLAGS_SET(mask, bit) ? "enable" : "disable", n, p, fs); |
| clearerr(f); |
| |
| /* If we can't turn off a controller, leave it on in the reported resulting mask. This |
| * happens for example when we attempt to turn off a controller up in the tree that is |
| * used down in the tree. */ |
| if (!FLAGS_SET(mask, bit) && r == -EBUSY) /* You might wonder why we check for EBUSY |
| * only here, and not follow the same logic |
| * for other errors such as EINVAL or |
| * EOPNOTSUPP or anything else. That's |
| * because EBUSY indicates that the |
| * controllers is currently enabled and |
| * cannot be disabled because something down |
| * the hierarchy is still using it. Any other |
| * error most likely means something like "I |
| * never heard of this controller" or |
| * similar. In the former case it's hence |
| * safe to assume the controller is still on |
| * after the failed operation, while in the |
| * latter case it's safer to assume the |
| * controller is unknown and hence certainly |
| * not enabled. */ |
| ret |= bit; |
| } else { |
| /* Otherwise, if we managed to turn on a controller, set the bit reflecting that. */ |
| if (FLAGS_SET(mask, bit)) |
| ret |= bit; |
| } |
| } |
| } |
| |
| /* Let's return the precise set of controllers now enabled for the cgroup. */ |
| if (ret_result_mask) |
| *ret_result_mask = ret; |
| |
| return 0; |
| } |
| |
| bool cg_is_unified_wanted(void) { |
| static thread_local int wanted = -1; |
| int r; |
| bool b; |
| const bool is_default = DEFAULT_HIERARCHY == CGROUP_UNIFIED_ALL; |
| _cleanup_free_ char *c = NULL; |
| |
| /* If we have a cached value, return that. */ |
| if (wanted >= 0) |
| return wanted; |
| |
| /* If the hierarchy is already mounted, then follow whatever |
| * was chosen for it. */ |
| if (cg_unified_flush() >= 0) |
| return (wanted = unified_cache >= CGROUP_UNIFIED_ALL); |
| |
| /* If we were explicitly passed systemd.unified_cgroup_hierarchy, |
| * respect that. */ |
| r = proc_cmdline_get_bool("systemd.unified_cgroup_hierarchy", &b); |
| if (r > 0) |
| return (wanted = b); |
| |
| /* If we passed cgroup_no_v1=all with no other instructions, it seems |
| * highly unlikely that we want to use hybrid or legacy hierarchy. */ |
| r = proc_cmdline_get_key("cgroup_no_v1", 0, &c); |
| if (r > 0 && streq_ptr(c, "all")) |
| return (wanted = true); |
| |
| return (wanted = is_default); |
| } |
| |
| bool cg_is_legacy_wanted(void) { |
| static thread_local int wanted = -1; |
| |
| /* If we have a cached value, return that. */ |
| if (wanted >= 0) |
| return wanted; |
| |
| /* Check if we have cgroup v2 already mounted. */ |
| if (cg_unified_flush() >= 0 && |
| unified_cache == CGROUP_UNIFIED_ALL) |
| return (wanted = false); |
| |
| /* Otherwise, assume that at least partial legacy is wanted, |
| * since cgroup v2 should already be mounted at this point. */ |
| return (wanted = true); |
| } |
| |
| bool cg_is_hybrid_wanted(void) { |
| static thread_local int wanted = -1; |
| int r; |
| bool b; |
| const bool is_default = DEFAULT_HIERARCHY >= CGROUP_UNIFIED_SYSTEMD; |
| /* We default to true if the default is "hybrid", obviously, |
| * but also when the default is "unified", because if we get |
| * called, it means that unified hierarchy was not mounted. */ |
| |
| /* If we have a cached value, return that. */ |
| if (wanted >= 0) |
| return wanted; |
| |
| /* If the hierarchy is already mounted, then follow whatever |
| * was chosen for it. */ |
| if (cg_unified_flush() >= 0 && |
| unified_cache == CGROUP_UNIFIED_ALL) |
| return (wanted = false); |
| |
| /* Otherwise, let's see what the kernel command line has to say. |
| * Since checking is expensive, cache a non-error result. */ |
| r = proc_cmdline_get_bool("systemd.legacy_systemd_cgroup_controller", &b); |
| |
| /* The meaning of the kernel option is reversed wrt. to the return value |
| * of this function, hence the negation. */ |
| return (wanted = r > 0 ? !b : is_default); |
| } |
| |
| int cg_weight_parse(const char *s, uint64_t *ret) { |
| uint64_t u; |
| int r; |
| |
| if (isempty(s)) { |
| *ret = CGROUP_WEIGHT_INVALID; |
| return 0; |
| } |
| |
| r = safe_atou64(s, &u); |
| if (r < 0) |
| return r; |
| |
| if (u < CGROUP_WEIGHT_MIN || u > CGROUP_WEIGHT_MAX) |
| return -ERANGE; |
| |
| *ret = u; |
| return 0; |
| } |
| |
| const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX] = { |
| [CGROUP_IO_RBPS_MAX] = CGROUP_LIMIT_MAX, |
| [CGROUP_IO_WBPS_MAX] = CGROUP_LIMIT_MAX, |
| [CGROUP_IO_RIOPS_MAX] = CGROUP_LIMIT_MAX, |
| [CGROUP_IO_WIOPS_MAX] = CGROUP_LIMIT_MAX, |
| }; |
| |
| static const char* const cgroup_io_limit_type_table[_CGROUP_IO_LIMIT_TYPE_MAX] = { |
| [CGROUP_IO_RBPS_MAX] = "IOReadBandwidthMax", |
| [CGROUP_IO_WBPS_MAX] = "IOWriteBandwidthMax", |
| [CGROUP_IO_RIOPS_MAX] = "IOReadIOPSMax", |
| [CGROUP_IO_WIOPS_MAX] = "IOWriteIOPSMax", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP(cgroup_io_limit_type, CGroupIOLimitType); |
| |
| int cg_cpu_shares_parse(const char *s, uint64_t *ret) { |
| uint64_t u; |
| int r; |
| |
| if (isempty(s)) { |
| *ret = CGROUP_CPU_SHARES_INVALID; |
| return 0; |
| } |
| |
| r = safe_atou64(s, &u); |
| if (r < 0) |
| return r; |
| |
| if (u < CGROUP_CPU_SHARES_MIN || u > CGROUP_CPU_SHARES_MAX) |
| return -ERANGE; |
| |
| *ret = u; |
| return 0; |
| } |
| |
| int cg_blkio_weight_parse(const char *s, uint64_t *ret) { |
| uint64_t u; |
| int r; |
| |
| if (isempty(s)) { |
| *ret = CGROUP_BLKIO_WEIGHT_INVALID; |
| return 0; |
| } |
| |
| r = safe_atou64(s, &u); |
| if (r < 0) |
| return r; |
| |
| if (u < CGROUP_BLKIO_WEIGHT_MIN || u > CGROUP_BLKIO_WEIGHT_MAX) |
| return -ERANGE; |
| |
| *ret = u; |
| return 0; |
| } |
| |
| bool is_cgroup_fs(const struct statfs *s) { |
| return is_fs_type(s, CGROUP_SUPER_MAGIC) || |
| is_fs_type(s, CGROUP2_SUPER_MAGIC); |
| } |
| |
| bool fd_is_cgroup_fs(int fd) { |
| struct statfs s; |
| |
| if (fstatfs(fd, &s) < 0) |
| return -errno; |
| |
| return is_cgroup_fs(&s); |
| } |
| |
| static const char *const cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = { |
| [CGROUP_CONTROLLER_CPU] = "cpu", |
| [CGROUP_CONTROLLER_CPUACCT] = "cpuacct", |
| [CGROUP_CONTROLLER_IO] = "io", |
| [CGROUP_CONTROLLER_BLKIO] = "blkio", |
| [CGROUP_CONTROLLER_MEMORY] = "memory", |
| [CGROUP_CONTROLLER_DEVICES] = "devices", |
| [CGROUP_CONTROLLER_PIDS] = "pids", |
| [CGROUP_CONTROLLER_BPF_FIREWALL] = "bpf-firewall", |
| [CGROUP_CONTROLLER_BPF_DEVICES] = "bpf-devices", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController); |
| |
| CGroupMask get_cpu_accounting_mask(void) { |
| static CGroupMask needed_mask = (CGroupMask) -1; |
| |
| /* On kernel ≥4.15 with unified hierarchy, cpu.stat's usage_usec is |
| * provided externally from the CPU controller, which means we don't |
| * need to enable the CPU controller just to get metrics. This is good, |
| * because enabling the CPU controller comes at a minor performance |
| * hit, especially when it's propagated deep into large hierarchies. |
| * There's also no separate CPU accounting controller available within |
| * a unified hierarchy. |
| * |
| * This combination of factors results in the desired cgroup mask to |
| * enable for CPU accounting varying as follows: |
| * |
| * ╔═════════════════════╤═════════════════════╗ |
| * ║ Linux ≥4.15 │ Linux <4.15 ║ |
| * ╔═══════════════╬═════════════════════╪═════════════════════╣ |
| * ║ Unified ║ nothing │ CGROUP_MASK_CPU ║ |
| * ╟───────────────╫─────────────────────┼─────────────────────╢ |
| * ║ Hybrid/Legacy ║ CGROUP_MASK_CPUACCT │ CGROUP_MASK_CPUACCT ║ |
| * ╚═══════════════╩═════════════════════╧═════════════════════╝ |
| * |
| * We check kernel version here instead of manually checking whether |
| * cpu.stat is present for every cgroup, as that check in itself would |
| * already be fairly expensive. |
| * |
| * Kernels where this patch has been backported will therefore have the |
| * CPU controller enabled unnecessarily. This is more expensive than |
| * necessary, but harmless. ☺️ |
| */ |
| |
| if (needed_mask == (CGroupMask) -1) { |
| if (cg_all_unified()) { |
| struct utsname u; |
| assert_se(uname(&u) >= 0); |
| |
| if (str_verscmp(u.release, "4.15") < 0) |
| needed_mask = CGROUP_MASK_CPU; |
| else |
| needed_mask = 0; |
| } else |
| needed_mask = CGROUP_MASK_CPUACCT; |
| } |
| |
| return needed_mask; |
| } |
| |
| bool cpu_accounting_is_cheap(void) { |
| return get_cpu_accounting_mask() == 0; |
| } |