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-rw-r--r--src/cgroup-util.c694
1 files changed, 694 insertions, 0 deletions
diff --git a/src/cgroup-util.c b/src/cgroup-util.c
new file mode 100644
index 0000000000..9337817b6b
--- /dev/null
+++ b/src/cgroup-util.c
@@ -0,0 +1,694 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <libcgroup.h>
+
+#include "cgroup-util.h"
+#include "log.h"
+#include "set.h"
+#include "macro.h"
+#include "util.h"
+
+int cg_translate_error(int error, int _errno) {
+
+ switch (error) {
+
+ case ECGROUPNOTCOMPILED:
+ case ECGROUPNOTMOUNTED:
+ case ECGROUPNOTEXIST:
+ case ECGROUPNOTCREATED:
+ return -ENOENT;
+
+ case ECGINVAL:
+ return -EINVAL;
+
+ case ECGROUPNOTALLOWED:
+ return -EPERM;
+
+ case ECGOTHER:
+ return -_errno;
+ }
+
+ return -EIO;
+}
+
+static struct cgroup* cg_new(const char *controller, const char *path) {
+ struct cgroup *cgroup;
+
+ assert(path);
+ assert(controller);
+
+ if (!(cgroup = cgroup_new_cgroup(path)))
+ return NULL;
+
+ if (!cgroup_add_controller(cgroup, controller)) {
+ cgroup_free(&cgroup);
+ return NULL;
+ }
+
+ return cgroup;
+}
+
+int cg_kill(const char *controller, const char *path, int sig, bool ignore_self) {
+ bool killed = false, done = false;
+ Set *s;
+ pid_t my_pid;
+ int r, ret = 0;
+
+ assert(controller);
+ assert(path);
+ assert(sig >= 0);
+
+ /* 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 = set_new(trivial_hash_func, trivial_compare_func)))
+ return -ENOMEM;
+
+ my_pid = getpid();
+
+ do {
+ void *iterator = NULL;
+ pid_t pid = 0;
+
+ done = true;
+
+ r = cgroup_get_task_begin(path, controller, &iterator, &pid);
+ while (r == 0) {
+
+ if (pid == my_pid && ignore_self)
+ goto next;
+
+ if (set_get(s, INT_TO_PTR(pid)) == INT_TO_PTR(pid))
+ goto next;
+
+ /* If we haven't killed this process yet, kill
+ * it */
+
+ if (kill(pid, sig) < 0 && errno != ESRCH) {
+ if (ret == 0)
+ ret = -errno;
+ }
+
+ killed = true;
+ done = false;
+
+ if ((r = set_put(s, INT_TO_PTR(pid))) < 0)
+ goto loop_exit;
+
+ next:
+ r = cgroup_get_task_next(&iterator, &pid);
+ }
+
+ if (r == 0 || r == ECGEOF)
+ r = 0;
+ else if (r == ECGOTHER && errno == ENOENT)
+ r = -ESRCH;
+ else
+ r = cg_translate_error(r, errno);
+
+ loop_exit:
+ assert_se(cgroup_get_task_end(&iterator) == 0);
+
+ /* 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 && r >= 0);
+
+ set_free(s);
+
+ if (ret < 0)
+ return ret;
+
+ if (r < 0)
+ return r;
+
+ return !!killed;
+}
+
+int cg_kill_recursive(const char *controller, const char *path, int sig, bool ignore_self) {
+ struct cgroup_file_info info;
+ int level = 0, r, ret = 0;
+ void *iterator = NULL;
+ bool killed = false;
+
+ assert(path);
+ assert(controller);
+ assert(sig >= 0);
+
+ zero(info);
+
+ r = cgroup_walk_tree_begin(controller, path, 0, &iterator, &info, &level);
+ while (r == 0) {
+ int k;
+ char *p;
+
+ if (info.type != CGROUP_FILE_TYPE_DIR)
+ goto next;
+
+ if (asprintf(&p, "%s/%s", path, info.path) < 0) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ k = cg_kill(controller, p, sig, ignore_self);
+ free(p);
+
+ if (k < 0) {
+ if (ret == 0)
+ ret = k;
+ } else if (k > 0)
+ killed = true;
+
+ next:
+
+ r = cgroup_walk_tree_next(0, &iterator, &info, level);
+ }
+
+ if (ret == 0) {
+ if (r == 0 || r == ECGEOF)
+ ret = !!killed;
+ else if (r == ECGOTHER && errno == ENOENT)
+ ret = -ESRCH;
+ else
+ ret = cg_translate_error(r, errno);
+ }
+
+ assert_se(cgroup_walk_tree_end(&iterator) == 0);
+
+ return ret;
+}
+
+int cg_kill_recursive_and_wait(const char *controller, const char *path) {
+ unsigned i;
+
+ assert(path);
+ assert(controller);
+
+ /* This safely kills all processes; first it sends a SIGTERM,
+ * then checks 8 times after 50ms whether the group is
+ * now empty, and finally kills everything that is left with
+ * SIGKILL */
+
+ for (i = 0; i < 10; i++) {
+int sig, r;
+
+ if (i <= 0)
+ sig = SIGTERM;
+ else if (i >= 9)
+ sig = SIGKILL;
+ else
+ sig = 0;
+
+ if ((r = cg_kill_recursive(controller, path, sig, true)) <= 0)
+ return r;
+
+ usleep(50 * USEC_PER_MSEC);
+ }
+
+ return 0;
+}
+
+int cg_migrate(const char *controller, const char *from, const char *to, bool ignore_self) {
+ bool migrated = false, done = false;
+ struct cgroup *dest;
+ int r, ret = 0;
+ pid_t my_pid;
+
+ assert(controller);
+ assert(from);
+ assert(to);
+
+ if (!(dest = cg_new(controller, to)))
+ return -ENOMEM;
+
+ my_pid = getpid();
+
+ do {
+ void *iterator = NULL;
+ pid_t pid = 0;
+
+ done = true;
+
+ r = cgroup_get_task_begin(from, controller, &iterator, &pid);
+ while (r == 0) {
+
+ if (pid == my_pid && ignore_self)
+ goto next;
+
+ if ((r = cgroup_attach_task_pid(dest, pid)) != 0) {
+ if (ret == 0)
+ r = cg_translate_error(r, errno);
+ }
+
+ migrated = true;
+ done = false;
+
+ next:
+
+ r = cgroup_get_task_next(&iterator, &pid);
+ }
+
+ if (r == 0 || r == ECGEOF)
+ r = 0;
+ else if (r == ECGOTHER && errno == ENOENT)
+ r = -ESRCH;
+ else
+ r = cg_translate_error(r, errno);
+
+ assert_se(cgroup_get_task_end(&iterator) == 0);
+
+ } while (!done && r >= 0);
+
+ cgroup_free(&dest);
+
+ if (ret < 0)
+ return ret;
+
+ if (r < 0)
+ return r;
+
+ return !!migrated;
+}
+
+int cg_migrate_recursive(const char *controller, const char *from, const char *to, bool ignore_self) {
+ struct cgroup_file_info info;
+ int level = 0, r, ret = 0;
+ void *iterator = NULL;
+ bool migrated = false;
+
+ assert(controller);
+ assert(from);
+ assert(to);
+
+ zero(info);
+
+ r = cgroup_walk_tree_begin(controller, from, 0, &iterator, &info, &level);
+ while (r == 0) {
+ int k;
+ char *p;
+
+ if (info.type != CGROUP_FILE_TYPE_DIR)
+ goto next;
+
+ if (asprintf(&p, "%s/%s", from, info.path) < 0) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ k = cg_migrate(controller, p, to, ignore_self);
+ free(p);
+
+ if (k < 0) {
+ if (ret == 0)
+ ret = k;
+ } else if (k > 0)
+ migrated = true;
+
+ next:
+ r = cgroup_walk_tree_next(0, &iterator, &info, level);
+ }
+
+ if (ret == 0) {
+ if (r == 0 || r == ECGEOF)
+ r = !!migrated;
+ else if (r == ECGOTHER && errno == ENOENT)
+ r = -ESRCH;
+ else
+ r = cg_translate_error(r, errno);
+ }
+
+ assert_se(cgroup_walk_tree_end(&iterator) == 0);
+
+ return ret;
+}
+
+int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
+ char *mp;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if ((r = cgroup_get_subsys_mount_point(controller, &mp)) != 0)
+ return cg_translate_error(r, errno);
+
+ if (suffix)
+ r = asprintf(fs, "%s/%s/%s", mp, path, suffix);
+ else
+ r = asprintf(fs, "%s/%s", mp, path);
+
+ free(mp);
+
+ return r < 0 ? -ENOMEM : 0;
+}
+
+int cg_trim(const char *controller, const char *path, bool delete_root) {
+ char *fs;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if ((r = cg_get_path(controller, path, NULL, &fs)) < 0)
+ return r;
+
+ r = rm_rf(fs, true, delete_root);
+ free(fs);
+
+ return r;
+}
+
+int cg_delete(const char *controller, const char *path) {
+ struct cgroup *cg;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if (!(cg = cg_new(controller, path)))
+ return -ENOMEM;
+
+ if ((r = cgroup_delete_cgroup_ext(cg, CGFLAG_DELETE_RECURSIVE|CGFLAG_DELETE_IGNORE_MIGRATION)) != 0) {
+ r = cg_translate_error(r, errno);
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ cgroup_free(&cg);
+
+ return r;
+}
+
+int cg_create(const char *controller, const char *path) {
+ struct cgroup *cg;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if (!(cg = cg_new(controller, path)))
+ return -ENOMEM;
+
+ if ((r = cgroup_create_cgroup(cg, 1)) != 0) {
+ r = cg_translate_error(r, errno);
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ cgroup_free(&cg);
+
+ return r;
+}
+
+int cg_attach(const char *controller, const char *path, pid_t pid) {
+ struct cgroup *cg;
+ int r;
+
+ assert(controller);
+ assert(path);
+ assert(pid >= 0);
+
+ if (!(cg = cg_new(controller, path)))
+ return -ENOMEM;
+
+ if (pid == 0)
+ pid = getpid();
+
+ if ((r = cgroup_attach_task_pid(cg, pid))) {
+ r = cg_translate_error(r, errno);
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ cgroup_free(&cg);
+
+ return r;
+}
+
+int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
+ struct cgroup *cg;
+ int r;
+
+ assert(controller);
+ assert(path);
+ assert(pid >= 0);
+
+ if (!(cg = cg_new(controller, path)))
+ return -ENOMEM;
+
+ if ((r = cgroup_create_cgroup(cg, 1)) != 0) {
+ r = cg_translate_error(r, errno);
+ goto finish;
+ }
+
+ if (pid == 0)
+ pid = getpid();
+
+ if ((r = cgroup_attach_task_pid(cg, pid))) {
+ r = cg_translate_error(r, errno);
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ cgroup_free(&cg);
+
+ return r;
+}
+
+int cg_set_group_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid) {
+ char *fs;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if ((r = cg_get_path(controller, path, NULL, &fs)) < 0)
+ return r;
+
+ r = chmod_and_chown(fs, mode, uid, gid);
+ free(fs);
+
+ return r;
+}
+
+int cg_set_task_access(const char *controller, const char *path, mode_t mode, uid_t uid, gid_t gid) {
+ char *fs;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ if ((r = cg_get_path(controller, path, "tasks", &fs)) < 0)
+ return r;
+
+ r = chmod_and_chown(fs, mode, uid, gid);
+ free(fs);
+
+ return r;
+}
+
+int cg_get_by_pid(const char *controller, pid_t pid, char **path) {
+ int r;
+ char *p = NULL;
+
+ assert(controller);
+ assert(pid > 0);
+ assert(path);
+
+ if ((r = cgroup_get_current_controller_path(pid, controller, &p)) != 0)
+ return cg_translate_error(r, errno);
+
+ assert(p);
+
+ *path = p;
+ return 0;
+}
+
+int cg_install_release_agent(const char *controller, const char *agent) {
+ char *mp = NULL, *path = NULL, *contents = NULL, *line = NULL, *sc;
+ int r;
+
+ assert(controller);
+ assert(agent);
+
+ if ((r = cgroup_get_subsys_mount_point(controller, &mp)) != 0)
+ return cg_translate_error(r, errno);
+
+ if (asprintf(&path, "%s/release_agent", mp) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if ((r = read_one_line_file(path, &contents)) < 0)
+ goto finish;
+
+ sc = strstrip(contents);
+
+ if (sc[0] == 0) {
+
+ if (asprintf(&line, "%s\n", agent) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if ((r = write_one_line_file(path, line)) < 0)
+ goto finish;
+
+ } else if (!streq(sc, agent)) {
+ r = -EEXIST;
+ goto finish;
+ }
+
+ free(path);
+ path = NULL;
+ if (asprintf(&path, "%s/notify_on_release", mp) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ free(contents);
+ contents = NULL;
+ if ((r = read_one_line_file(path, &contents)) < 0)
+ goto finish;
+
+ sc = strstrip(contents);
+
+ if (streq(sc, "0")) {
+ if ((r = write_one_line_file(path, "1\n")) < 0)
+ goto finish;
+ } else if (!streq(sc, "1")) {
+ r = -EIO;
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ free(mp);
+ free(path);
+ free(contents);
+ free(line);
+
+ return r;
+}
+
+int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
+ void *iterator = NULL;
+ pid_t pid = 0;
+ int r;
+
+ assert(controller);
+ assert(path);
+
+ r = cgroup_get_task_begin(path, controller, &iterator, &pid);
+ while (r == 0) {
+
+ if (ignore_self&& pid == getpid())
+ goto next;
+
+ break;
+
+ next:
+ r = cgroup_get_task_next(&iterator, &pid);
+ }
+
+
+ if (r == ECGEOF)
+ r = 1;
+ else if (r != 0)
+ r = cg_translate_error(r, errno);
+ else
+ r = 0;
+
+ assert_se(cgroup_get_task_end(&iterator) == 0);
+
+ return r;
+}
+
+int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
+ struct cgroup_file_info info;
+ int level = 0, r, ret = 0;
+ void *iterator = NULL;
+ bool empty = true;
+
+ assert(controller);
+ assert(path);
+
+ zero(info);
+
+ r = cgroup_walk_tree_begin(controller, path, 0, &iterator, &info, &level);
+ while (r == 0) {
+ int k;
+ char *p;
+
+ if (info.type != CGROUP_FILE_TYPE_DIR)
+ goto next;
+
+ if (asprintf(&p, "%s/%s", path, info.path) < 0) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ k = cg_is_empty(controller, p, ignore_self);
+ free(p);
+
+ if (k < 0) {
+ ret = k;
+ break;
+ } else if (k == 0) {
+ empty = false;
+ break;
+ }
+
+ next:
+ r = cgroup_walk_tree_next(0, &iterator, &info, level);
+ }
+
+ if (ret == 0) {
+ if (r == 0 || r == ECGEOF)
+ ret = !!empty;
+ else if (r == ECGOTHER && errno == ENOENT)
+ ret = -ESRCH;
+ else
+ ret = cg_translate_error(r, errno);
+ }
+
+ assert_se(cgroup_walk_tree_end(&iterator) == 0);
+
+ return ret;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-10 14:47:31 +0000