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cgroup-util: drop "controller" argument from various cgroup helper calls

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systemd's own cgroup hierarchy is special to us, we use it to actually
manage processes. Because of that many calls tha apply to cgroups are
only ever called with the SYSTEMD_CGROUP_CONTROLLER as controller
argument. Let's hence remove the argument altogether.

This in particular touches the kill and xattr routines.

This changes no behaviour, we just drop an argument that is always set
to the same value anyway.

This is preparation to eventually getting rid of the cgroupvs1, because
on cgroupvs2 the cgroup paths do not change for different controllers,
there's only a single hierarchy there.
This commit is contained in:
Lennart Poettering
2023-10-05 11:11:04 +02:00
parent 5ee3c914a4
commit bd1791b597
11 changed files with 119 additions and 116 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/basic/cgroup-util.c
+49 -53
View File
@@ -280,7 +280,6 @@ int cg_rmdir(const char *controller, const char *path) {
}
static int cg_kill_items(
const char *controller,
const char *path,
int sig,
CGroupFlags flags,
@@ -318,7 +317,7 @@ static int cg_kill_items(
pid_t pid = 0;
done = true;
r = cg_enumerate_items(controller, path, &f, item);
r = cg_enumerate_items(SYSTEMD_CGROUP_CONTROLLER, path, &f, item);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
@@ -382,7 +381,6 @@ static int cg_kill_items(
}
int cg_kill(
const char *controller,
const char *path,
int sig,
CGroupFlags flags,
@@ -392,7 +390,7 @@ int cg_kill(
int r, ret;
r = cg_kill_items(controller, path, sig, flags, s, log_kill, userdata, "cgroup.procs");
r = cg_kill_items(path, sig, flags, s, log_kill, userdata, "cgroup.procs");
if (r < 0 || sig != SIGKILL)
return r;
@@ -401,32 +399,32 @@ int cg_kill(
/* 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);
r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
if (r < 0)
return r;
if (r == 0)
return ret;
r = cg_kill_items(controller, path, sig, flags, s, log_kill, userdata, "cgroup.threads");
r = cg_kill_items(path, sig, flags, s, log_kill, userdata, "cgroup.threads");
if (r < 0)
return r;
return r > 0 || ret > 0;
}
int cg_kill_kernel_sigkill(const char *controller, const char *path) {
/* Kills the cgroup at `path` directly by writing to its cgroup.kill file.
* This sends SIGKILL to all processes in the cgroup and has the advantage of
* being completely atomic, unlike cg_kill_items. */
int r;
int cg_kill_kernel_sigkill(const char *path) {
/* Kills the cgroup at `path` directly by writing to its cgroup.kill file. This sends SIGKILL to all
* processes in the cgroup and has the advantage of being completely atomic, unlike cg_kill_items(). */
_cleanup_free_ char *killfile = NULL;
int r;
assert(path);
if (!cg_kill_supported())
return -EOPNOTSUPP;
r = cg_get_path(controller, path, "cgroup.kill", &killfile);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, "cgroup.kill", &killfile);
if (r < 0)
return r;
@@ -438,7 +436,6 @@ int cg_kill_kernel_sigkill(const char *controller, const char *path) {
}
int cg_kill_recursive(
const char *controller,
const char *path,
int sig,
CGroupFlags flags,
@@ -446,57 +443,60 @@ int cg_kill_recursive(
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 (sig == SIGKILL && cg_kill_supported() &&
!FLAGS_SET(flags, CGROUP_IGNORE_SELF) && !s && !log_kill) {
!FLAGS_SET(flags, CGROUP_IGNORE_SELF) && !s && !log_kill)
/* ignore CGROUP_SIGCONT, since this is a no-op alongside SIGKILL */
ret = cg_kill_kernel_sigkill(controller, path);
if (ret < 0)
return ret;
} else {
ret = cg_kill_kernel_sigkill(path);
else {
_cleanup_set_free_ Set *allocated_set = NULL;
_cleanup_closedir_ DIR *d = NULL;
if (!s) {
s = allocated_set = set_new(NULL);
if (!s)
return -ENOMEM;
}
ret = cg_kill(controller, path, sig, flags, s, log_kill, userdata);
ret = cg_kill(path, sig, flags, s, log_kill, userdata);
r = cg_enumerate_subgroups(controller, path, &d);
r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
if (r != -ENOENT)
RET_GATHER(ret, r);
return ret;
}
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
for (;;) {
_cleanup_free_ char *fn = NULL, *p = NULL;
r = cg_read_subgroup(d, &fn);
if (r < 0) {
RET_GATHER(ret, r);
break;
}
if (r == 0)
break;
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);
r = cg_kill_recursive(p, sig, flags, s, log_kill, userdata);
if (r != 0 && ret >= 0)
ret = r;
}
if (ret >= 0 && r < 0)
ret = r;
}
if (FLAGS_SET(flags, CGROUP_REMOVE)) {
r = cg_rmdir(controller, path);
if (r < 0 && ret >= 0 && !IN_SET(r, -ENOENT, -EBUSY))
return r;
r = cg_rmdir(SYSTEMD_CGROUP_CONTROLLER, path);
if (!IN_SET(r, -ENOENT, -EBUSY))
RET_GATHER(ret, r);
}
return ret;
@@ -649,7 +649,7 @@ int cg_get_path_and_check(const char *controller, const char *path, const char *
return cg_get_path(controller, path, suffix, fs);
}
int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags) {
int cg_set_xattr(const char *path, const char *name, const void *value, size_t size, int flags) {
_cleanup_free_ char *fs = NULL;
int r;
@@ -657,14 +657,14 @@ int cg_set_xattr(const char *controller, const char *path, const char *name, con
assert(name);
assert(value || size <= 0);
r = cg_get_path(controller, path, NULL, &fs);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
return RET_NERRNO(setxattr(fs, name, value, size, flags));
}
int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size) {
int cg_get_xattr(const char *path, const char *name, void *value, size_t size) {
_cleanup_free_ char *fs = NULL;
ssize_t n;
int r;
@@ -672,7 +672,7 @@ int cg_get_xattr(const char *controller, const char *path, const char *name, voi
assert(path);
assert(name);
r = cg_get_path(controller, path, NULL, &fs);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
@@ -683,46 +683,42 @@ int cg_get_xattr(const char *controller, const char *path, const char *name, voi
return (int) n;
}
int cg_get_xattr_malloc(const char *controller, const char *path, const char *name, char **ret) {
int cg_get_xattr_malloc(const char *path, const char *name, char **ret) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
r = cg_get_path(controller, path, NULL, &fs);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
r = lgetxattr_malloc(fs, name, ret);
if (r < 0)
return r;
return r;
return lgetxattr_malloc(fs, name, ret);
}
int cg_get_xattr_bool(const char *controller, const char *path, const char *name) {
int cg_get_xattr_bool(const char *path, const char *name) {
_cleanup_free_ char *val = NULL;
int r;
assert(path);
assert(name);
r = cg_get_xattr_malloc(controller, path, name, &val);
r = cg_get_xattr_malloc(path, name, &val);
if (r < 0)
return r;
return parse_boolean(val);
}
int cg_remove_xattr(const char *controller, const char *path, const char *name) {
int cg_remove_xattr(const char *path, const char *name) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
assert(name);
r = cg_get_path(controller, path, NULL, &fs);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
return r;
@@ -1753,12 +1749,12 @@ int cg_slice_to_path(const char *unit, char **ret) {
return 0;
}
int cg_is_threaded(const char *controller, const char *path) {
int cg_is_threaded(const char *path) {
_cleanup_free_ char *fs = NULL, *contents = NULL;
_cleanup_strv_free_ char **v = NULL;
int r;
r = cg_get_path(controller, path, "cgroup.type", &fs);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, "cgroup.type", &fs);
if (r < 0)
return r;
@@ -1845,14 +1841,14 @@ int cg_get_attribute_as_bool(const char *controller, const char *path, const cha
return 0;
}
int cg_get_owner(const char *controller, const char *path, uid_t *ret_uid) {
int cg_get_owner(const char *path, uid_t *ret_uid) {
_cleanup_free_ char *f = NULL;
struct stat stats;
int r;
assert(ret_uid);
r = cg_get_path(controller, path, NULL, &f);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &f);
if (r < 0)
return r;
src/basic/cgroup-util.h
+10 -10
View File
@@ -193,9 +193,9 @@ typedef enum CGroupFlags {
typedef int (*cg_kill_log_func_t)(pid_t pid, int sig, void *userdata);
int cg_kill(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_kill_kernel_sigkill(const char *controller, const char *path);
int cg_kill_recursive(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_kill(const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_kill_kernel_sigkill(const char *path);
int cg_kill_recursive(const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
int cg_split_spec(const char *spec, char **ret_controller, char **ret_path);
int cg_mangle_path(const char *path, char **result);
@@ -207,7 +207,7 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path);
int cg_rmdir(const char *controller, const char *path);
int cg_is_threaded(const char *controller, const char *path);
int cg_is_threaded(const char *path);
typedef enum {
CG_KEY_MODE_GRACEFUL = 1 << 0,
@@ -240,14 +240,14 @@ int cg_get_attribute_as_uint64(const char *controller, const char *path, const c
/* Does a parse_boolean() on the attribute contents and sets ret accordingly */
int cg_get_attribute_as_bool(const char *controller, const char *path, const char *attribute, bool *ret);
int cg_get_owner(const char *controller, const char *path, uid_t *ret_uid);
int cg_get_owner(const char *path, uid_t *ret_uid);
int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags);
int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size);
int cg_get_xattr_malloc(const char *controller, const char *path, const char *name, char **ret);
int cg_set_xattr(const char *path, const char *name, const void *value, size_t size, int flags);
int cg_get_xattr(const char *path, const char *name, void *value, size_t size);
int cg_get_xattr_malloc(const char *path, const char *name, char **ret);
/* Returns negative on error, and 0 or 1 on success for the bool value */
int cg_get_xattr_bool(const char *controller, const char *path, const char *name);
int cg_remove_xattr(const char *controller, const char *path, const char *name);
int cg_get_xattr_bool(const char *path, const char *name);
int cg_remove_xattr(const char *path, const char *name);
int cg_install_release_agent(const char *controller, const char *agent);
int cg_uninstall_release_agent(const char *controller);