Rivoreo Source Code Repositories
src.rivoreo.one / systemd-stable / v243-rc1 / . / src / core / cgroup.c
blob: 6e0afa4bca3806ffd50133f0b39c12bdfd266650 [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <fcntl.h>
#include <fnmatch.h>
#include "sd-messages.h"
#include "alloc-util.h"
#include "blockdev-util.h"
#include "bpf-devices.h"
#include "bpf-firewall.h"
#include "btrfs-util.h"
#include "bus-error.h"
#include "cgroup-util.h"
#include "cgroup.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "nulstr-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
#include "procfs-util.h"
#include "special.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "string-table.h"
#include "string-util.h"
#include "virt.h"
#define CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC)
/* Returns the log level to use when cgroup attribute writes fail. When an attribute is missing or we have access
* problems we downgrade to LOG_DEBUG. This is supposed to be nice to container managers and kernels which want to mask
* out specific attributes from us. */
#define LOG_LEVEL_CGROUP_WRITE(r) (IN_SET(abs(r), ENOENT, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING)
bool manager_owns_host_root_cgroup(Manager *m) {
assert(m);
/* Returns true if we are managing the root cgroup. Note that it isn't sufficient to just check whether the
* group root path equals "/" since that will also be the case if CLONE_NEWCGROUP is in the mix. Since there's
* appears to be no nice way to detect whether we are in a CLONE_NEWCGROUP namespace we instead just check if
* we run in any kind of container virtualization. */
if (MANAGER_IS_USER(m))
return false;
if (detect_container() > 0)
return false;
return empty_or_root(m->cgroup_root);
}
bool unit_has_host_root_cgroup(Unit *u) {
assert(u);
/* Returns whether this unit manages the root cgroup. This will return true if this unit is the root slice and
* the manager manages the root cgroup. */
if (!manager_owns_host_root_cgroup(u->manager))
return false;
return unit_has_name(u, SPECIAL_ROOT_SLICE);
}
static int set_attribute_and_warn(Unit *u, const char *controller, const char *attribute, const char *value) {
int r;
r = cg_set_attribute(controller, u->cgroup_path, attribute, value);
if (r < 0)
log_unit_full(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to set '%s' attribute on '%s' to '%.*s': %m",
strna(attribute), isempty(u->cgroup_path) ? "/" : u->cgroup_path, (int) strcspn(value, NEWLINE), value);
return r;
}
static void cgroup_compat_warn(void) {
static bool cgroup_compat_warned = false;
if (cgroup_compat_warned)
return;
log_warning("cgroup compatibility translation between legacy and unified hierarchy settings activated. "
"See cgroup-compat debug messages for details.");
cgroup_compat_warned = true;
}
#define log_cgroup_compat(unit, fmt, ...) do { \
cgroup_compat_warn(); \
log_unit_debug(unit, "cgroup-compat: " fmt, ##__VA_ARGS__); \
} while (false)
void cgroup_context_init(CGroupContext *c) {
assert(c);
/* Initialize everything to the kernel defaults. */
*c = (CGroupContext) {
.cpu_weight = CGROUP_WEIGHT_INVALID,
.startup_cpu_weight = CGROUP_WEIGHT_INVALID,
.cpu_quota_per_sec_usec = USEC_INFINITY,
.cpu_quota_period_usec = USEC_INFINITY,
.cpu_shares = CGROUP_CPU_SHARES_INVALID,
.startup_cpu_shares = CGROUP_CPU_SHARES_INVALID,
.memory_high = CGROUP_LIMIT_MAX,
.memory_max = CGROUP_LIMIT_MAX,
.memory_swap_max = CGROUP_LIMIT_MAX,
.memory_limit = CGROUP_LIMIT_MAX,
.io_weight = CGROUP_WEIGHT_INVALID,
.startup_io_weight = CGROUP_WEIGHT_INVALID,
.blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID,
.startup_blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID,
.tasks_max = CGROUP_LIMIT_MAX,
};
}
void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) {
assert(c);
assert(a);
LIST_REMOVE(device_allow, c->device_allow, a);
free(a->path);
free(a);
}
void cgroup_context_free_io_device_weight(CGroupContext *c, CGroupIODeviceWeight *w) {
assert(c);
assert(w);
LIST_REMOVE(device_weights, c->io_device_weights, w);
free(w->path);
free(w);
}
void cgroup_context_free_io_device_latency(CGroupContext *c, CGroupIODeviceLatency *l) {
assert(c);
assert(l);
LIST_REMOVE(device_latencies, c->io_device_latencies, l);
free(l->path);
free(l);
}
void cgroup_context_free_io_device_limit(CGroupContext *c, CGroupIODeviceLimit *l) {
assert(c);
assert(l);
LIST_REMOVE(device_limits, c->io_device_limits, l);
free(l->path);
free(l);
}
void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) {
assert(c);
assert(w);
LIST_REMOVE(device_weights, c->blockio_device_weights, w);
free(w->path);
free(w);
}
void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b) {
assert(c);
assert(b);
LIST_REMOVE(device_bandwidths, c->blockio_device_bandwidths, b);
free(b->path);
free(b);
}
void cgroup_context_done(CGroupContext *c) {
assert(c);
while (c->io_device_weights)
cgroup_context_free_io_device_weight(c, c->io_device_weights);
while (c->io_device_latencies)
cgroup_context_free_io_device_latency(c, c->io_device_latencies);
while (c->io_device_limits)
cgroup_context_free_io_device_limit(c, c->io_device_limits);
while (c->blockio_device_weights)
cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights);
while (c->blockio_device_bandwidths)
cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths);
while (c->device_allow)
cgroup_context_free_device_allow(c, c->device_allow);
c->ip_address_allow = ip_address_access_free_all(c->ip_address_allow);
c->ip_address_deny = ip_address_access_free_all(c->ip_address_deny);
c->ip_filters_ingress = strv_free(c->ip_filters_ingress);
c->ip_filters_egress = strv_free(c->ip_filters_egress);
}
void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
_cleanup_free_ char *disable_controllers_str = NULL;
CGroupIODeviceLimit *il;
CGroupIODeviceWeight *iw;
CGroupIODeviceLatency *l;
CGroupBlockIODeviceBandwidth *b;
CGroupBlockIODeviceWeight *w;
CGroupDeviceAllow *a;
IPAddressAccessItem *iaai;
char **path;
char u[FORMAT_TIMESPAN_MAX];
char v[FORMAT_TIMESPAN_MAX];
assert(c);
assert(f);
prefix = strempty(prefix);
(void) cg_mask_to_string(c->disable_controllers, &disable_controllers_str);
fprintf(f,
"%sCPUAccounting=%s\n"
"%sIOAccounting=%s\n"
"%sBlockIOAccounting=%s\n"
"%sMemoryAccounting=%s\n"
"%sTasksAccounting=%s\n"
"%sIPAccounting=%s\n"
"%sCPUWeight=%" PRIu64 "\n"
"%sStartupCPUWeight=%" PRIu64 "\n"
"%sCPUShares=%" PRIu64 "\n"
"%sStartupCPUShares=%" PRIu64 "\n"
"%sCPUQuotaPerSecSec=%s\n"
"%sCPUQuotaPeriodSec=%s\n"
"%sIOWeight=%" PRIu64 "\n"
"%sStartupIOWeight=%" PRIu64 "\n"
"%sBlockIOWeight=%" PRIu64 "\n"
"%sStartupBlockIOWeight=%" PRIu64 "\n"
"%sDefaultMemoryMin=%" PRIu64 "\n"
"%sDefaultMemoryLow=%" PRIu64 "\n"
"%sMemoryMin=%" PRIu64 "\n"
"%sMemoryLow=%" PRIu64 "\n"
"%sMemoryHigh=%" PRIu64 "\n"
"%sMemoryMax=%" PRIu64 "\n"
"%sMemorySwapMax=%" PRIu64 "\n"
"%sMemoryLimit=%" PRIu64 "\n"
"%sTasksMax=%" PRIu64 "\n"
"%sDevicePolicy=%s\n"
"%sDisableControllers=%s\n"
"%sDelegate=%s\n",
prefix, yes_no(c->cpu_accounting),
prefix, yes_no(c->io_accounting),
prefix, yes_no(c->blockio_accounting),
prefix, yes_no(c->memory_accounting),
prefix, yes_no(c->tasks_accounting),
prefix, yes_no(c->ip_accounting),
prefix, c->cpu_weight,
prefix, c->startup_cpu_weight,
prefix, c->cpu_shares,
prefix, c->startup_cpu_shares,
prefix, format_timespan(u, sizeof(u), c->cpu_quota_per_sec_usec, 1),
prefix, format_timespan(v, sizeof(v), c->cpu_quota_period_usec, 1),
prefix, c->io_weight,
prefix, c->startup_io_weight,
prefix, c->blockio_weight,
prefix, c->startup_blockio_weight,
prefix, c->default_memory_min,
prefix, c->default_memory_low,
prefix, c->memory_min,
prefix, c->memory_low,
prefix, c->memory_high,
prefix, c->memory_max,
prefix, c->memory_swap_max,
prefix, c->memory_limit,
prefix, c->tasks_max,
prefix, cgroup_device_policy_to_string(c->device_policy),
prefix, strempty(disable_controllers_str),
prefix, yes_no(c->delegate));
if (c->delegate) {
_cleanup_free_ char *t = NULL;
(void) cg_mask_to_string(c->delegate_controllers, &t);
fprintf(f, "%sDelegateControllers=%s\n",
prefix,
strempty(t));
}
LIST_FOREACH(device_allow, a, c->device_allow)
fprintf(f,
"%sDeviceAllow=%s %s%s%s\n",
prefix,
a->path,
a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : "");
LIST_FOREACH(device_weights, iw, c->io_device_weights)
fprintf(f,
"%sIODeviceWeight=%s %" PRIu64 "\n",
prefix,
iw->path,
iw->weight);
LIST_FOREACH(device_latencies, l, c->io_device_latencies)
fprintf(f,
"%sIODeviceLatencyTargetSec=%s %s\n",
prefix,
l->path,
format_timespan(u, sizeof(u), l->target_usec, 1));
LIST_FOREACH(device_limits, il, c->io_device_limits) {
char buf[FORMAT_BYTES_MAX];
CGroupIOLimitType type;
for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++)
if (il->limits[type] != cgroup_io_limit_defaults[type])
fprintf(f,
"%s%s=%s %s\n",
prefix,
cgroup_io_limit_type_to_string(type),
il->path,
format_bytes(buf, sizeof(buf), il->limits[type]));
}
LIST_FOREACH(device_weights, w, c->blockio_device_weights)
fprintf(f,
"%sBlockIODeviceWeight=%s %" PRIu64,
prefix,
w->path,
w->weight);
LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
char buf[FORMAT_BYTES_MAX];
if (b->rbps != CGROUP_LIMIT_MAX)
fprintf(f,
"%sBlockIOReadBandwidth=%s %s\n",
prefix,
b->path,
format_bytes(buf, sizeof(buf), b->rbps));
if (b->wbps != CGROUP_LIMIT_MAX)
fprintf(f,
"%sBlockIOWriteBandwidth=%s %s\n",
prefix,
b->path,
format_bytes(buf, sizeof(buf), b->wbps));
}
LIST_FOREACH(items, iaai, c->ip_address_allow) {
_cleanup_free_ char *k = NULL;
(void) in_addr_to_string(iaai->family, &iaai->address, &k);
fprintf(f, "%sIPAddressAllow=%s/%u\n", prefix, strnull(k), iaai->prefixlen);
}
LIST_FOREACH(items, iaai, c->ip_address_deny) {
_cleanup_free_ char *k = NULL;
(void) in_addr_to_string(iaai->family, &iaai->address, &k);
fprintf(f, "%sIPAddressDeny=%s/%u\n", prefix, strnull(k), iaai->prefixlen);
}
STRV_FOREACH(path, c->ip_filters_ingress)
fprintf(f, "%sIPIngressFilterPath=%s\n", prefix, *path);
STRV_FOREACH(path, c->ip_filters_egress)
fprintf(f, "%sIPEgressFilterPath=%s\n", prefix, *path);
}
int cgroup_add_device_allow(CGroupContext *c, const char *dev, const char *mode) {
_cleanup_free_ CGroupDeviceAllow *a = NULL;
_cleanup_free_ char *d = NULL;
assert(c);
assert(dev);
assert(isempty(mode) || in_charset(mode, "rwm"));
a = new(CGroupDeviceAllow, 1);
if (!a)
return -ENOMEM;
d = strdup(dev);
if (!d)
return -ENOMEM;
*a = (CGroupDeviceAllow) {
.path = TAKE_PTR(d),
.r = isempty(mode) || strchr(mode, 'r'),
.w = isempty(mode) || strchr(mode, 'w'),
.m = isempty(mode) || strchr(mode, 'm'),
};
LIST_PREPEND(device_allow, c->device_allow, a);
TAKE_PTR(a);
return 0;
}
#define UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(entry) \
uint64_t unit_get_ancestor_##entry(Unit *u) { \
CGroupContext *c; \
\
/* 1. Is entry set in this unit? If so, use that. \
* 2. Is the default for this entry set in any \
* ancestor? If so, use that. \
* 3. Otherwise, return CGROUP_LIMIT_MIN. */ \
\
assert(u); \
\
c = unit_get_cgroup_context(u); \
if (c && c->entry##_set) \
return c->entry; \
\
while ((u = UNIT_DEREF(u->slice))) { \
c = unit_get_cgroup_context(u); \
if (c && c->default_##entry##_set) \
return c->default_##entry; \
} \
\
/* We've reached the root, but nobody had default for \
* this entry set, so set it to the kernel default. */ \
return CGROUP_LIMIT_MIN; \
}
UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(memory_low);
UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(memory_min);
static void cgroup_xattr_apply(Unit *u) {
char ids[SD_ID128_STRING_MAX];
int r;
assert(u);
if (!MANAGER_IS_SYSTEM(u->manager))
return;
if (sd_id128_is_null(u->invocation_id))
return;
r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path,
"trusted.invocation_id",
sd_id128_to_string(u->invocation_id, ids), 32,
0);
if (r < 0)
log_unit_debug_errno(u, r, "Failed to set invocation ID on control group %s, ignoring: %m", u->cgroup_path);
}
static int lookup_block_device(const char *p, dev_t *ret) {
dev_t rdev, dev = 0;
mode_t mode;
int r;
assert(p);
assert(ret);
r = device_path_parse_major_minor(p, &mode, &rdev);
if (r == -ENODEV) { /* not a parsable device node, need to go to disk */
struct stat st;
if (stat(p, &st) < 0)
return log_warning_errno(errno, "Couldn't stat device '%s': %m", p);
rdev = (dev_t)st.st_rdev;
dev = (dev_t)st.st_dev;
mode = st.st_mode;
} else if (r < 0)
return log_warning_errno(r, "Failed to parse major/minor from path '%s': %m", p);
if (S_ISCHR(mode)) {
log_warning("Device node '%s' is a character device, but block device needed.", p);
return -ENOTBLK;
} else if (S_ISBLK(mode))
*ret = rdev;
else if (major(dev) != 0)
*ret = dev; /* If this is not a device node then use the block device this file is stored on */
else {
/* If this is btrfs, getting the backing block device is a bit harder */
r = btrfs_get_block_device(p, ret);
if (r < 0 && r != -ENOTTY)
return log_warning_errno(r, "Failed to determine block device backing btrfs file system '%s': %m", p);
if (r == -ENOTTY) {
log_warning("'%s' is not a block device node, and file system block device cannot be determined or is not local.", p);
return -ENODEV;
}
}
/* If this is a LUKS device, try to get the originating block device */
(void) block_get_originating(*ret, ret);
/* If this is a partition, try to get the originating block device */
(void) block_get_whole_disk(*ret, ret);
return 0;
}
static int whitelist_device(BPFProgram *prog, const char *path, const char *node, const char *acc) {
dev_t rdev;
mode_t mode;
int r;
assert(path);
assert(acc);
/* Some special handling for /dev/block/%u:%u, /dev/char/%u:%u, /run/systemd/inaccessible/chr and
* /run/systemd/inaccessible/blk paths. Instead of stat()ing these we parse out the major/minor directly. This
* means clients can use these path without the device node actually around */
r = device_path_parse_major_minor(node, &mode, &rdev);
if (r < 0) {
if (r != -ENODEV)
return log_warning_errno(r, "Couldn't parse major/minor from device path '%s': %m", node);
struct stat st;
if (stat(node, &st) < 0)
return log_warning_errno(errno, "Couldn't stat device %s: %m", node);
if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
log_warning("%s is not a device.", node);
return -ENODEV;
}
rdev = (dev_t) st.st_rdev;
mode = st.st_mode;
}
if (cg_all_unified() > 0) {
if (!prog)
return 0;
return cgroup_bpf_whitelist_device(prog, S_ISCHR(mode) ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK,
major(rdev), minor(rdev), acc);
} else {
char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4];
sprintf(buf,
"%c %u:%u %s",
S_ISCHR(mode) ? 'c' : 'b',
major(rdev), minor(rdev),
acc);
/* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL here. */
r = cg_set_attribute("devices", path, "devices.allow", buf);
if (r < 0)
return log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING,
r, "Failed to set devices.allow on %s: %m", path);
return 0;
}
}
static int whitelist_major(BPFProgram *prog, const char *path, const char *name, char type, const char *acc) {
_cleanup_fclose_ FILE *f = NULL;
char buf[2+DECIMAL_STR_MAX(unsigned)+3+4];
bool good = false;
unsigned maj;
int r;
assert(path);
assert(acc);
assert(IN_SET(type, 'b', 'c'));
if (streq(name, "*")) {
/* If the name is a wildcard, then apply this list to all devices of this type */
if (cg_all_unified() > 0) {
if (!prog)
return 0;
(void) cgroup_bpf_whitelist_class(prog, type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, acc);
} else {
xsprintf(buf, "%c *:* %s", type, acc);
r = cg_set_attribute("devices", path, "devices.allow", buf);
if (r < 0)
log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set devices.allow on %s: %m", path);
return 0;
}
}
if (safe_atou(name, &maj) >= 0 && DEVICE_MAJOR_VALID(maj)) {
/* The name is numeric and suitable as major. In that case, let's take is major, and create the entry
* directly */
if (cg_all_unified() > 0) {
if (!prog)
return 0;
(void) cgroup_bpf_whitelist_major(prog,
type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK,
maj, acc);
} else {
xsprintf(buf, "%c %u:* %s", type, maj, acc);
r = cg_set_attribute("devices", path, "devices.allow", buf);
if (r < 0)
log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set devices.allow on %s: %m", path);
}
return 0;
}
f = fopen("/proc/devices", "re");
if (!f)
return log_warning_errno(errno, "Cannot open /proc/devices to resolve %s (%c): %m", name, type);
for (;;) {
_cleanup_free_ char *line = NULL;
char *w, *p;
r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return log_warning_errno(r, "Failed to read /proc/devices: %m");
if (r == 0)
break;
if (type == 'c' && streq(line, "Character devices:")) {
good = true;
continue;
}
if (type == 'b' && streq(line, "Block devices:")) {
good = true;
continue;
}
if (isempty(line)) {
good = false;
continue;
}
if (!good)
continue;
p = strstrip(line);
w = strpbrk(p, WHITESPACE);
if (!w)
continue;
*w = 0;
r = safe_atou(p, &maj);
if (r < 0)
continue;
if (maj <= 0)
continue;
w++;
w += strspn(w, WHITESPACE);
if (fnmatch(name, w, 0) != 0)
continue;
if (cg_all_unified() > 0) {
if (!prog)
continue;
(void) cgroup_bpf_whitelist_major(prog,
type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK,
maj, acc);
} else {
sprintf(buf,
"%c %u:* %s",
type,
maj,
acc);
/* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL
* here. */
r = cg_set_attribute("devices", path, "devices.allow", buf);
if (r < 0)
log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING,
r, "Failed to set devices.allow on %s: %m", path);
}
}
return 0;
}
static bool cgroup_context_has_cpu_weight(CGroupContext *c) {
return c->cpu_weight != CGROUP_WEIGHT_INVALID ||
c->startup_cpu_weight != CGROUP_WEIGHT_INVALID;
}
static bool cgroup_context_has_cpu_shares(CGroupContext *c) {
return c->cpu_shares != CGROUP_CPU_SHARES_INVALID ||
c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID;
}
static uint64_t cgroup_context_cpu_weight(CGroupContext *c, ManagerState state) {
if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) &&
c->startup_cpu_weight != CGROUP_WEIGHT_INVALID)
return c->startup_cpu_weight;
else if (c->cpu_weight != CGROUP_WEIGHT_INVALID)
return c->cpu_weight;
else
return CGROUP_WEIGHT_DEFAULT;
}
static uint64_t cgroup_context_cpu_shares(CGroupContext *c, ManagerState state) {
if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) &&
c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID)
return c->startup_cpu_shares;
else if (c->cpu_shares != CGROUP_CPU_SHARES_INVALID)
return c->cpu_shares;
else
return CGROUP_CPU_SHARES_DEFAULT;
}
usec_t cgroup_cpu_adjust_period(usec_t period, usec_t quota, usec_t resolution, usec_t max_period) {
/* kernel uses a minimum resolution of 1ms, so both period and (quota * period)
* need to be higher than that boundary. quota is specified in USecPerSec.
* Additionally, period must be at most max_period. */
assert(quota > 0);
return MIN(MAX3(period, resolution, resolution * USEC_PER_SEC / quota), max_period);
}
static usec_t cgroup_cpu_adjust_period_and_log(Unit *u, usec_t period, usec_t quota) {
usec_t new_period;
if (quota == USEC_INFINITY)
/* Always use default period for infinity quota. */
return CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC;
if (period == USEC_INFINITY)
/* Default period was requested. */
period = CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC;
/* Clamp to interval [1ms, 1s] */
new_period = cgroup_cpu_adjust_period(period, quota, USEC_PER_MSEC, USEC_PER_SEC);
if (new_period != period) {
char v[FORMAT_TIMESPAN_MAX];
log_unit_full(u, u->warned_clamping_cpu_quota_period ? LOG_DEBUG : LOG_WARNING, 0,
"Clamping CPU interval for cpu.max: period is now %s",
format_timespan(v, sizeof(v), new_period, 1));
u->warned_clamping_cpu_quota_period = true;
}
return new_period;
}
static void cgroup_apply_unified_cpu_weight(Unit *u, uint64_t weight) {
char buf[DECIMAL_STR_MAX(uint64_t) + 2];
xsprintf(buf, "%" PRIu64 "\n", weight);
(void) set_attribute_and_warn(u, "cpu", "cpu.weight", buf);
}
static void cgroup_apply_unified_cpu_quota(Unit *u, usec_t quota, usec_t period) {
char buf[(DECIMAL_STR_MAX(usec_t) + 1) * 2 + 1];
period = cgroup_cpu_adjust_period_and_log(u, period, quota);
if (quota != USEC_INFINITY)
xsprintf(buf, USEC_FMT " " USEC_FMT "\n",
MAX(quota * period / USEC_PER_SEC, USEC_PER_MSEC), period);
else
xsprintf(buf, "max " USEC_FMT "\n", period);
(void) set_attribute_and_warn(u, "cpu", "cpu.max", buf);
}
static void cgroup_apply_legacy_cpu_shares(Unit *u, uint64_t shares) {
char buf[DECIMAL_STR_MAX(uint64_t) + 2];
xsprintf(buf, "%" PRIu64 "\n", shares);
(void) set_attribute_and_warn(u, "cpu", "cpu.shares", buf);
}
static void cgroup_apply_legacy_cpu_quota(Unit *u, usec_t quota, usec_t period) {
char buf[DECIMAL_STR_MAX(usec_t) + 2];
period = cgroup_cpu_adjust_period_and_log(u, period, quota);
xsprintf(buf, USEC_FMT "\n", period);
(void) set_attribute_and_warn(u, "cpu", "cpu.cfs_period_us", buf);
if (quota != USEC_INFINITY) {
xsprintf(buf, USEC_FMT "\n", MAX(quota * period / USEC_PER_SEC, USEC_PER_MSEC));
(void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", buf);
} else
(void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", "-1\n");
}
static uint64_t cgroup_cpu_shares_to_weight(uint64_t shares) {
return CLAMP(shares * CGROUP_WEIGHT_DEFAULT / CGROUP_CPU_SHARES_DEFAULT,
CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX);
}
static uint64_t cgroup_cpu_weight_to_shares(uint64_t weight) {
return CLAMP(weight * CGROUP_CPU_SHARES_DEFAULT / CGROUP_WEIGHT_DEFAULT,
CGROUP_CPU_SHARES_MIN, CGROUP_CPU_SHARES_MAX);
}
static bool cgroup_context_has_io_config(CGroupContext *c) {
return c->io_accounting ||
c->io_weight != CGROUP_WEIGHT_INVALID ||
c->startup_io_weight != CGROUP_WEIGHT_INVALID ||
c->io_device_weights ||
c->io_device_latencies ||
c->io_device_limits;
}
static bool cgroup_context_has_blockio_config(CGroupContext *c) {
return c->blockio_accounting ||
c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID ||
c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID ||
c->blockio_device_weights ||
c->blockio_device_bandwidths;
}
static uint64_t cgroup_context_io_weight(CGroupContext *c, ManagerState state) {
if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) &&
c->startup_io_weight != CGROUP_WEIGHT_INVALID)
return c->startup_io_weight;
else if (c->io_weight != CGROUP_WEIGHT_INVALID)
return c->io_weight;
else
return CGROUP_WEIGHT_DEFAULT;
}
static uint64_t cgroup_context_blkio_weight(CGroupContext *c, ManagerState state) {
if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) &&
c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID)
return c->startup_blockio_weight;
else if (c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID)
return c->blockio_weight;
else
return CGROUP_BLKIO_WEIGHT_DEFAULT;
}
static uint64_t cgroup_weight_blkio_to_io(uint64_t blkio_weight) {
return CLAMP(blkio_weight * CGROUP_WEIGHT_DEFAULT / CGROUP_BLKIO_WEIGHT_DEFAULT,
CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX);
}
static uint64_t cgroup_weight_io_to_blkio(uint64_t io_weight) {
return CLAMP(io_weight * CGROUP_BLKIO_WEIGHT_DEFAULT / CGROUP_WEIGHT_DEFAULT,
CGROUP_BLKIO_WEIGHT_MIN, CGROUP_BLKIO_WEIGHT_MAX);
}
static void cgroup_apply_io_device_weight(Unit *u, const char *dev_path, uint64_t io_weight) {
char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1];
dev_t dev;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return;
xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), io_weight);
(void) set_attribute_and_warn(u, "io", "io.weight", buf);
}
static void cgroup_apply_blkio_device_weight(Unit *u, const char *dev_path, uint64_t blkio_weight) {
char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1];
dev_t dev;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return;
xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), blkio_weight);
(void) set_attribute_and_warn(u, "blkio", "blkio.weight_device", buf);
}
static void cgroup_apply_io_device_latency(Unit *u, const char *dev_path, usec_t target) {
char buf[DECIMAL_STR_MAX(dev_t)*2+2+7+DECIMAL_STR_MAX(uint64_t)+1];
dev_t dev;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return;
if (target != USEC_INFINITY)
xsprintf(buf, "%u:%u target=%" PRIu64 "\n", major(dev), minor(dev), target);
else
xsprintf(buf, "%u:%u target=max\n", major(dev), minor(dev));
(void) set_attribute_and_warn(u, "io", "io.latency", buf);
}
static void cgroup_apply_io_device_limit(Unit *u, const char *dev_path, uint64_t *limits) {
char limit_bufs[_CGROUP_IO_LIMIT_TYPE_MAX][DECIMAL_STR_MAX(uint64_t)];
char buf[DECIMAL_STR_MAX(dev_t)*2+2+(6+DECIMAL_STR_MAX(uint64_t)+1)*4];
CGroupIOLimitType type;
dev_t dev;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return;
for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++)
if (limits[type] != cgroup_io_limit_defaults[type])
xsprintf(limit_bufs[type], "%" PRIu64, limits[type]);
else
xsprintf(limit_bufs[type], "%s", limits[type] == CGROUP_LIMIT_MAX ? "max" : "0");
xsprintf(buf, "%u:%u rbps=%s wbps=%s riops=%s wiops=%s\n", major(dev), minor(dev),
limit_bufs[CGROUP_IO_RBPS_MAX], limit_bufs[CGROUP_IO_WBPS_MAX],
limit_bufs[CGROUP_IO_RIOPS_MAX], limit_bufs[CGROUP_IO_WIOPS_MAX]);
(void) set_attribute_and_warn(u, "io", "io.max", buf);
}
static void cgroup_apply_blkio_device_limit(Unit *u, const char *dev_path, uint64_t rbps, uint64_t wbps) {
char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1];
dev_t dev;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return;
sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), rbps);
(void) set_attribute_and_warn(u, "blkio", "blkio.throttle.read_bps_device", buf);
sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), wbps);
(void) set_attribute_and_warn(u, "blkio", "blkio.throttle.write_bps_device", buf);
}
static bool unit_has_unified_memory_config(Unit *u) {
CGroupContext *c;
assert(u);
c = unit_get_cgroup_context(u);
assert(c);
return c->memory_min > 0 || unit_get_ancestor_memory_low(u) > 0 ||
c->memory_high != CGROUP_LIMIT_MAX || c->memory_max != CGROUP_LIMIT_MAX ||
c->memory_swap_max != CGROUP_LIMIT_MAX;
}
static void cgroup_apply_unified_memory_limit(Unit *u, const char *file, uint64_t v) {
char buf[DECIMAL_STR_MAX(uint64_t) + 1] = "max\n";
if (v != CGROUP_LIMIT_MAX)
xsprintf(buf, "%" PRIu64 "\n", v);
(void) set_attribute_and_warn(u, "memory", file, buf);
}
static void cgroup_apply_firewall(Unit *u) {
assert(u);
/* Best-effort: let's apply IP firewalling and/or accounting if that's enabled */
if (bpf_firewall_compile(u) < 0)
return;
(void) bpf_firewall_load_custom(u);
(void) bpf_firewall_install(u);
}
static void cgroup_context_apply(
Unit *u,
CGroupMask apply_mask,
ManagerState state) {
const char *path;
CGroupContext *c;
bool is_host_root, is_local_root;
int r;
assert(u);
/* Nothing to do? Exit early! */
if (apply_mask == 0)
return;
/* Some cgroup attributes are not supported on the host root cgroup, hence silently ignore them here. And other
* attributes should only be managed for cgroups further down the tree. */
is_local_root = unit_has_name(u, SPECIAL_ROOT_SLICE);
is_host_root = unit_has_host_root_cgroup(u);
assert_se(c = unit_get_cgroup_context(u));
assert_se(path = u->cgroup_path);
if (is_local_root) /* Make sure we don't try to display messages with an empty path. */
path = "/";
/* We generally ignore errors caused by read-only mounted cgroup trees (assuming we are running in a container
* then), and missing cgroups, i.e. EROFS and ENOENT. */
/* In fully unified mode these attributes don't exist on the host cgroup root. On legacy the weights exist, but
* setting the weight makes very little sense on the host root cgroup, as there are no other cgroups at this
* level. The quota exists there too, but any attempt to write to it is refused with EINVAL. Inside of
* containers we want to leave control of these to the container manager (and if cgroup v2 delegation is used
* we couldn't even write to them if we wanted to). */
if ((apply_mask & CGROUP_MASK_CPU) && !is_local_root) {
if (cg_all_unified() > 0) {
uint64_t weight;
if (cgroup_context_has_cpu_weight(c))
weight = cgroup_context_cpu_weight(c, state);
else if (cgroup_context_has_cpu_shares(c)) {
uint64_t shares;
shares = cgroup_context_cpu_shares(c, state);
weight = cgroup_cpu_shares_to_weight(shares);
log_cgroup_compat(u, "Applying [Startup]CPUShares=%" PRIu64 " as [Startup]CPUWeight=%" PRIu64 " on %s",
shares, weight, path);
} else
weight = CGROUP_WEIGHT_DEFAULT;
cgroup_apply_unified_cpu_weight(u, weight);
cgroup_apply_unified_cpu_quota(u, c->cpu_quota_per_sec_usec, c->cpu_quota_period_usec);
} else {
uint64_t shares;
if (cgroup_context_has_cpu_weight(c)) {
uint64_t weight;
weight = cgroup_context_cpu_weight(c, state);
shares = cgroup_cpu_weight_to_shares(weight);
log_cgroup_compat(u, "Applying [Startup]CPUWeight=%" PRIu64 " as [Startup]CPUShares=%" PRIu64 " on %s",
weight, shares, path);
} else if (cgroup_context_has_cpu_shares(c))
shares = cgroup_context_cpu_shares(c, state);
else
shares = CGROUP_CPU_SHARES_DEFAULT;
cgroup_apply_legacy_cpu_shares(u, shares);
cgroup_apply_legacy_cpu_quota(u, c->cpu_quota_per_sec_usec, c->cpu_quota_period_usec);
}
}
/* The 'io' controller attributes are not exported on the host's root cgroup (being a pure cgroup v2
* controller), and in case of containers we want to leave control of these attributes to the container manager
* (and we couldn't access that stuff anyway, even if we tried if proper delegation is used). */
if ((apply_mask & CGROUP_MASK_IO) && !is_local_root) {
char buf[8+DECIMAL_STR_MAX(uint64_t)+1];
bool has_io, has_blockio;
uint64_t weight;
has_io = cgroup_context_has_io_config(c);
has_blockio = cgroup_context_has_blockio_config(c);
if (has_io)
weight = cgroup_context_io_weight(c, state);
else if (has_blockio) {
uint64_t blkio_weight;
blkio_weight = cgroup_context_blkio_weight(c, state);
weight = cgroup_weight_blkio_to_io(blkio_weight);
log_cgroup_compat(u, "Applying [Startup]BlockIOWeight=%" PRIu64 " as [Startup]IOWeight=%" PRIu64,
blkio_weight, weight);
} else
weight = CGROUP_WEIGHT_DEFAULT;
xsprintf(buf, "default %" PRIu64 "\n", weight);
(void) set_attribute_and_warn(u, "io", "io.weight", buf);
if (has_io) {
CGroupIODeviceLatency *latency;
CGroupIODeviceLimit *limit;
CGroupIODeviceWeight *w;
LIST_FOREACH(device_weights, w, c->io_device_weights)
cgroup_apply_io_device_weight(u, w->path, w->weight);
LIST_FOREACH(device_limits, limit, c->io_device_limits)
cgroup_apply_io_device_limit(u, limit->path, limit->limits);
LIST_FOREACH(device_latencies, latency, c->io_device_latencies)
cgroup_apply_io_device_latency(u, latency->path, latency->target_usec);
} else if (has_blockio) {
CGroupBlockIODeviceWeight *w;
CGroupBlockIODeviceBandwidth *b;
LIST_FOREACH(device_weights, w, c->blockio_device_weights) {
weight = cgroup_weight_blkio_to_io(w->weight);
log_cgroup_compat(u, "Applying BlockIODeviceWeight=%" PRIu64 " as IODeviceWeight=%" PRIu64 " for %s",
w->weight, weight, w->path);
cgroup_apply_io_device_weight(u, w->path, weight);
}
LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) {
uint64_t limits[_CGROUP_IO_LIMIT_TYPE_MAX];
CGroupIOLimitType type;
for (type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++)
limits[type] = cgroup_io_limit_defaults[type];
limits[CGROUP_IO_RBPS_MAX] = b->rbps;
limits[CGROUP_IO_WBPS_MAX] = b->wbps;
log_cgroup_compat(u, "Applying BlockIO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as IO{Read|Write}BandwidthMax= for %s",
b->rbps, b->wbps, b->path);
cgroup_apply_io_device_limit(u, b->path, limits);
}
}
}
if (apply_mask & CGROUP_MASK_BLKIO) {
bool has_io, has_blockio;
has_io = cgroup_context_has_io_config(c);
has_blockio = cgroup_context_has_blockio_config(c);
/* Applying a 'weight' never makes sense for the host root cgroup, and for containers this should be
* left to our container manager, too. */
if (!is_local_root) {
char buf[DECIMAL_STR_MAX(uint64_t)+1];
uint64_t weight;
if (has_io) {
uint64_t io_weight;
io_weight = cgroup_context_io_weight(c, state);
weight = cgroup_weight_io_to_blkio(cgroup_context_io_weight(c, state));
log_cgroup_compat(u, "Applying [Startup]IOWeight=%" PRIu64 " as [Startup]BlockIOWeight=%" PRIu64,
io_weight, weight);
} else if (has_blockio)
weight = cgroup_context_blkio_weight(c, state);
else
weight = CGROUP_BLKIO_WEIGHT_DEFAULT;
xsprintf(buf, "%" PRIu64 "\n", weight);
(void) set_attribute_and_warn(u, "blkio", "blkio.weight", buf);
if (has_io) {
CGroupIODeviceWeight *w;
LIST_FOREACH(device_weights, w, c->io_device_weights) {
weight = cgroup_weight_io_to_blkio(w->weight);
log_cgroup_compat(u, "Applying IODeviceWeight=%" PRIu64 " as BlockIODeviceWeight=%" PRIu64 " for %s",
w->weight, weight, w->path);
cgroup_apply_blkio_device_weight(u, w->path, weight);
}
} else if (has_blockio) {
CGroupBlockIODeviceWeight *w;
LIST_FOREACH(device_weights, w, c->blockio_device_weights)
cgroup_apply_blkio_device_weight(u, w->path, w->weight);
}
}
/* The bandwidth limits are something that make sense to be applied to the host's root but not container
* roots, as there we want the container manager to handle it */
if (is_host_root || !is_local_root) {
if (has_io) {
CGroupIODeviceLimit *l;
LIST_FOREACH(device_limits, l, c->io_device_limits) {
log_cgroup_compat(u, "Applying IO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as BlockIO{Read|Write}BandwidthMax= for %s",
l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX], l->path);
cgroup_apply_blkio_device_limit(u, l->path, l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX]);
}
} else if (has_blockio) {
CGroupBlockIODeviceBandwidth *b;
LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths)
cgroup_apply_blkio_device_limit(u, b->path, b->rbps, b->wbps);
}
}
}
/* In unified mode 'memory' attributes do not exist on the root cgroup. In legacy mode 'memory.limit_in_bytes'
* exists on the root cgroup, but any writes to it are refused with EINVAL. And if we run in a container we
* want to leave control to the container manager (and if proper cgroup v2 delegation is used we couldn't even
* write to this if we wanted to.) */
if ((apply_mask & CGROUP_MASK_MEMORY) && !is_local_root) {
if (cg_all_unified() > 0) {
uint64_t max, swap_max = CGROUP_LIMIT_MAX;
if (unit_has_unified_memory_config(u)) {
max = c->memory_max;
swap_max = c->memory_swap_max;
} else {
max = c->memory_limit;
if (max != CGROUP_LIMIT_MAX)
log_cgroup_compat(u, "Applying MemoryLimit=%" PRIu64 " as MemoryMax=", max);
}
cgroup_apply_unified_memory_limit(u, "memory.min", c->memory_min);
cgroup_apply_unified_memory_limit(u, "memory.low", unit_get_ancestor_memory_low(u));
cgroup_apply_unified_memory_limit(u, "memory.high", c->memory_high);
cgroup_apply_unified_memory_limit(u, "memory.max", max);
cgroup_apply_unified_memory_limit(u, "memory.swap.max", swap_max);
(void) set_attribute_and_warn(u, "memory", "memory.oom.group", one_zero(c->memory_oom_group));
} else {
char buf[DECIMAL_STR_MAX(uint64_t) + 1];
uint64_t val;
if (unit_has_unified_memory_config(u)) {
val = c->memory_max;
log_cgroup_compat(u, "Applying MemoryMax=%" PRIi64 " as MemoryLimit=", val);
} else
val = c->memory_limit;
if (val == CGROUP_LIMIT_MAX)
strncpy(buf, "-1\n", sizeof(buf));
else
xsprintf(buf, "%" PRIu64 "\n", val);
(void) set_attribute_and_warn(u, "memory", "memory.limit_in_bytes", buf);
}
}
/* On cgroup v2 we can apply BPF everywhere. On cgroup v1 we apply it everywhere except for the root of
* containers, where we leave this to the manager */
if ((apply_mask & (CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES)) &&
(is_host_root || cg_all_unified() > 0 || !is_local_root)) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
CGroupDeviceAllow *a;
if (cg_all_unified() > 0) {
r = cgroup_init_device_bpf(&prog, c->device_policy, c->device_allow);
if (r < 0)
log_unit_warning_errno(u, r, "Failed to initialize device control bpf program: %m");
} else {
/* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL
* here. */
if (c->device_allow || c->device_policy != CGROUP_AUTO)
r = cg_set_attribute("devices", path, "devices.deny", "a");
else
r = cg_set_attribute("devices", path, "devices.allow", "a");
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to reset devices.allow/devices.deny: %m");
}
if (c->device_policy == CGROUP_CLOSED ||
(c->device_policy == CGROUP_AUTO && c->device_allow)) {
static const char auto_devices[] =
"/dev/null\0" "rwm\0"
"/dev/zero\0" "rwm\0"
"/dev/full\0" "rwm\0"
"/dev/random\0" "rwm\0"
"/dev/urandom\0" "rwm\0"
"/dev/tty\0" "rwm\0"
"/dev/ptmx\0" "rwm\0"
/* Allow /run/systemd/inaccessible/{chr,blk} devices for mapping InaccessiblePaths */
"/run/systemd/inaccessible/chr\0" "rwm\0"
"/run/systemd/inaccessible/blk\0" "rwm\0";
const char *x, *y;
NULSTR_FOREACH_PAIR(x, y, auto_devices)
(void) whitelist_device(prog, path, x, y);
/* PTS (/dev/pts) devices may not be duplicated, but accessed */
(void) whitelist_major(prog, path, "pts", 'c', "rw");
}
LIST_FOREACH(device_allow, a, c->device_allow) {
char acc[4], *val;
unsigned k = 0;
if (a->r)
acc[k++] = 'r';
if (a->w)
acc[k++] = 'w';
if (a->m)
acc[k++] = 'm';
if (k == 0)
continue;
acc[k++] = 0;
if (path_startswith(a->path, "/dev/"))
(void) whitelist_device(prog, path, a->path, acc);
else if ((val = startswith(a->path, "block-")))
(void) whitelist_major(prog, path, val, 'b', acc);
else if ((val = startswith(a->path, "char-")))
(void) whitelist_major(prog, path, val, 'c', acc);
else
log_unit_debug(u, "Ignoring device '%s' while writing cgroup attribute.", a->path);
}
r = cgroup_apply_device_bpf(u, prog, c->device_policy, c->device_allow);
if (r < 0) {
static bool warned = false;
log_full_errno(warned ? LOG_DEBUG : LOG_WARNING, r,
"Unit %s configures device ACL, but the local system doesn't seem to support the BPF-based device controller.\n"
"Proceeding WITHOUT applying ACL (all devices will be accessible)!\n"
"(This warning is only shown for the first loaded unit using device ACL.)", u->id);
warned = true;
}
}
if (apply_mask & CGROUP_MASK_PIDS) {
if (is_host_root) {
/* So, the "pids" controller does not expose anything on the root cgroup, in order not to
* replicate knobs exposed elsewhere needlessly. We abstract this away here however, and when
* the knobs of the root cgroup are modified propagate this to the relevant sysctls. There's a
* non-obvious asymmetry however: unlike the cgroup properties we don't really want to take
* exclusive ownership of the sysctls, but we still want to honour things if the user sets
* limits. Hence we employ sort of a one-way strategy: when the user sets a bounded limit
* through us it counts. When the user afterwards unsets it again (i.e. sets it to unbounded)
* it also counts. But if the user never set a limit through us (i.e. we are the default of
* "unbounded") we leave things unmodified. For this we manage a global boolean that we turn on
* the first time we set a limit. Note that this boolean is flushed out on manager reload,
* which is desirable so that there's an official way to release control of the sysctl from
* systemd: set the limit to unbounded and reload. */
if (c->tasks_max != CGROUP_LIMIT_MAX) {
u->manager->sysctl_pid_max_changed = true;
r = procfs_tasks_set_limit(c->tasks_max);
} else if (u->manager->sysctl_pid_max_changed)
r = procfs_tasks_set_limit(TASKS_MAX);
else
r = 0;
if (r < 0)
log_unit_full(u, LOG_LEVEL_CGROUP_WRITE(r), r,
"Failed to write to tasks limit sysctls: %m");
}
/* The attribute itself is not available on the host root cgroup, and in the container case we want to
* leave it for the container manager. */
if (!is_local_root) {
if (c->tasks_max != CGROUP_LIMIT_MAX) {
char buf[DECIMAL_STR_MAX(uint64_t) + 2];
sprintf(buf, "%" PRIu64 "\n", c->tasks_max);
(void) set_attribute_and_warn(u, "pids", "pids.max", buf);
} else
(void) set_attribute_and_warn(u, "pids", "pids.max", "max\n");
}
}
if (apply_mask & CGROUP_MASK_BPF_FIREWALL)
cgroup_apply_firewall(u);
}
static bool unit_get_needs_bpf_firewall(Unit *u) {
CGroupContext *c;
Unit *p;
assert(u);
c = unit_get_cgroup_context(u);
if (!c)
return false;
if (c->ip_accounting ||
c->ip_address_allow ||
c->ip_address_deny ||
c->ip_filters_ingress ||
c->ip_filters_egress)
return true;
/* If any parent slice has an IP access list defined, it applies too */
for (p = UNIT_DEREF(u->slice); p; p = UNIT_DEREF(p->slice)) {
c = unit_get_cgroup_context(p);
if (!c)
return false;
if (c->ip_address_allow ||
c->ip_address_deny)
return true;
}
return false;
}
static CGroupMask unit_get_cgroup_mask(Unit *u) {
CGroupMask mask = 0;
CGroupContext *c;
assert(u);
c = unit_get_cgroup_context(u);
assert(c);
/* Figure out which controllers we need, based on the cgroup context object */
if (c->cpu_accounting)
mask |= get_cpu_accounting_mask();
if (cgroup_context_has_cpu_weight(c) ||
cgroup_context_has_cpu_shares(c) ||
c->cpu_quota_per_sec_usec != USEC_INFINITY)
mask |= CGROUP_MASK_CPU;
if (cgroup_context_has_io_config(c) || cgroup_context_has_blockio_config(c))
mask |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO;
if (c->memory_accounting ||
c->memory_limit != CGROUP_LIMIT_MAX ||
unit_has_unified_memory_config(u))
mask |= CGROUP_MASK_MEMORY;
if (c->device_allow ||
c->device_policy != CGROUP_AUTO)
mask |= CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES;
if (c->tasks_accounting ||
c->tasks_max != CGROUP_LIMIT_MAX)
mask |= CGROUP_MASK_PIDS;
return CGROUP_MASK_EXTEND_JOINED(mask);
}
static CGroupMask unit_get_bpf_mask(Unit *u) {
CGroupMask mask = 0;
/* Figure out which controllers we need, based on the cgroup context, possibly taking into account children
* too. */
if (unit_get_needs_bpf_firewall(u))
mask |= CGROUP_MASK_BPF_FIREWALL;
return mask;
}
CGroupMask unit_get_own_mask(Unit *u) {
CGroupContext *c;
/* Returns the mask of controllers the unit needs for itself. If a unit is not properly loaded, return an empty
* mask, as we shouldn't reflect it in the cgroup hierarchy then. */
if (u->load_state != UNIT_LOADED)
return 0;
c = unit_get_cgroup_context(u);
if (!c)
return 0;
return (unit_get_cgroup_mask(u) | unit_get_bpf_mask(u) | unit_get_delegate_mask(u)) & ~unit_get_ancestor_disable_mask(u);
}
CGroupMask unit_get_delegate_mask(Unit *u) {
CGroupContext *c;
/* If delegation is turned on, then turn on selected controllers, unless we are on the legacy hierarchy and the
* process we fork into is known to drop privileges, and hence shouldn't get access to the controllers.
*
* Note that on the unified hierarchy it is safe to delegate controllers to unprivileged services. */
if (!unit_cgroup_delegate(u))
return 0;
if (cg_all_unified() <= 0) {
ExecContext *e;
e = unit_get_exec_context(u);
if (e && !exec_context_maintains_privileges(e))
return 0;
}
assert_se(c = unit_get_cgroup_context(u));
return CGROUP_MASK_EXTEND_JOINED(c->delegate_controllers);
}
CGroupMask unit_get_members_mask(Unit *u) {
assert(u);
/* Returns the mask of controllers all of the unit's children require, merged */
if (u->cgroup_members_mask_valid)
return u->cgroup_members_mask; /* Use cached value if possible */
u->cgroup_members_mask = 0;
if (u->type == UNIT_SLICE) {
void *v;
Unit *member;
Iterator i;
HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) {
if (UNIT_DEREF(member->slice) == u)
u->cgroup_members_mask |= unit_get_subtree_mask(member); /* note that this calls ourselves again, for the children */
}
}
u->cgroup_members_mask_valid = true;
return u->cgroup_members_mask;
}
CGroupMask unit_get_siblings_mask(Unit *u) {
assert(u);
/* Returns the mask of controllers all of the unit's siblings
* require, i.e. the members mask of the unit's parent slice
* if there is one. */
if (UNIT_ISSET(u->slice))
return unit_get_members_mask(UNIT_DEREF(u->slice));
return unit_get_subtree_mask(u); /* we are the top-level slice */
}
CGroupMask unit_get_disable_mask(Unit *u) {
CGroupContext *c;
c = unit_get_cgroup_context(u);
if (!c)
return 0;
return c->disable_controllers;
}
CGroupMask unit_get_ancestor_disable_mask(Unit *u) {
CGroupMask mask;
assert(u);
mask = unit_get_disable_mask(u);
/* Returns the mask of controllers which are marked as forcibly
* disabled in any ancestor unit or the unit in question. */
if (UNIT_ISSET(u->slice))
mask |= unit_get_ancestor_disable_mask(UNIT_DEREF(u->slice));
return mask;
}
CGroupMask unit_get_subtree_mask(Unit *u) {
/* Returns the mask of this subtree, meaning of the group
* itself and its children. */
return unit_get_own_mask(u) | unit_get_members_mask(u);
}
CGroupMask unit_get_target_mask(Unit *u) {
CGroupMask mask;
/* This returns the cgroup mask of all controllers to enable
* for a specific cgroup, i.e. everything it needs itself,
* plus all that its children need, plus all that its siblings
* need. This is primarily useful on the legacy cgroup
* hierarchy, where we need to duplicate each cgroup in each
* hierarchy that shall be enabled for it. */
mask = unit_get_own_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u);
if (mask & CGROUP_MASK_BPF_FIREWALL & ~u->manager->cgroup_supported)
emit_bpf_firewall_warning(u);
mask &= u->manager->cgroup_supported;
mask &= ~unit_get_ancestor_disable_mask(u);
return mask;
}
CGroupMask unit_get_enable_mask(Unit *u) {
CGroupMask mask;
/* This returns the cgroup mask of all controllers to enable
* for the children of a specific cgroup. This is primarily
* useful for the unified cgroup hierarchy, where each cgroup
* controls which controllers are enabled for its children. */
mask = unit_get_members_mask(u);
mask &= u->manager->cgroup_supported;
mask &= ~unit_get_ancestor_disable_mask(u);
return mask;
}
void unit_invalidate_cgroup_members_masks(Unit *u) {
assert(u);
/* Recurse invalidate the member masks cache all the way up the tree */
u->cgroup_members_mask_valid = false;
if (UNIT_ISSET(u->slice))
unit_invalidate_cgroup_members_masks(UNIT_DEREF(u->slice));
}
const char *unit_get_realized_cgroup_path(Unit *u, CGroupMask mask) {
/* Returns the realized cgroup path of the specified unit where all specified controllers are available. */
while (u) {
if (u->cgroup_path &&
u->cgroup_realized &&
FLAGS_SET(u->cgroup_realized_mask, mask))
return u->cgroup_path;
u = UNIT_DEREF(u->slice);
}
return NULL;
}
static const char *migrate_callback(CGroupMask mask, void *userdata) {
return unit_get_realized_cgroup_path(userdata, mask);
}
char *unit_default_cgroup_path(const Unit *u) {
_cleanup_free_ char *escaped = NULL, *slice = NULL;
int r;
assert(u);
if (unit_has_name(u, SPECIAL_ROOT_SLICE))
return strdup(u->manager->cgroup_root);
if (UNIT_ISSET(u->slice) && !unit_has_name(UNIT_DEREF(u->slice), SPECIAL_ROOT_SLICE)) {
r = cg_slice_to_path(UNIT_DEREF(u->slice)->id, &slice);
if (r < 0)
return NULL;
}
escaped = cg_escape(u->id);
if (!escaped)
return NULL;
return path_join(empty_to_root(u->manager->cgroup_root), slice, escaped);
}
int unit_set_cgroup_path(Unit *u, const char *path) {
_cleanup_free_ char *p = NULL;
int r;
assert(u);
if (streq_ptr(u->cgroup_path, path))
return 0;
if (path) {
p = strdup(path);
if (!p)
return -ENOMEM;
}
if (p) {
r = hashmap_put(u->manager->cgroup_unit, p, u);
if (r < 0)
return r;
}
unit_release_cgroup(u);
u->cgroup_path = TAKE_PTR(p);
return 1;
}
int unit_watch_cgroup(Unit *u) {
_cleanup_free_ char *events = NULL;
int r;
assert(u);
/* Watches the "cgroups.events" attribute of this unit's cgroup for "empty" events, but only if
* cgroupv2 is available. */
if (!u->cgroup_path)
return 0;
if (u->cgroup_control_inotify_wd >= 0)
return 0;
/* Only applies to the unified hierarchy */
r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
if (r < 0)
return log_error_errno(r, "Failed to determine whether the name=systemd hierarchy is unified: %m");
if (r == 0)
return 0;
/* No point in watch the top-level slice, it's never going to run empty. */
if (unit_has_name(u, SPECIAL_ROOT_SLICE))
return 0;
r = hashmap_ensure_allocated(&u->manager->cgroup_control_inotify_wd_unit, &trivial_hash_ops);
if (r < 0)
return log_oom();
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events", &events);
if (r < 0)
return log_oom();
u->cgroup_control_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY);
if (u->cgroup_control_inotify_wd < 0) {
if (errno == ENOENT) /* If the directory is already gone we don't need to track it, so this
* is not an error */
return 0;
return log_unit_error_errno(u, errno, "Failed to add control inotify watch descriptor for control group %s: %m", u->cgroup_path);
}
r = hashmap_put(u->manager->cgroup_control_inotify_wd_unit, INT_TO_PTR(u->cgroup_control_inotify_wd), u);
if (r < 0)
return log_unit_error_errno(u, r, "Failed to add control inotify watch descriptor to hash map: %m");
return 0;
}
int unit_watch_cgroup_memory(Unit *u) {
_cleanup_free_ char *events = NULL;
CGroupContext *c;
int r;
assert(u);
/* Watches the "memory.events" attribute of this unit's cgroup for "oom_kill" events, but only if
* cgroupv2 is available. */
if (!u->cgroup_path)
return 0;
c = unit_get_cgroup_context(u);
if (!c)
return 0;
/* The "memory.events" attribute is only available if the memory controller is on. Let's hence tie
* this to memory accounting, in a way watching for OOM kills is a form of memory accounting after
* all. */
if (!c->memory_accounting)
return 0;
/* Don't watch inner nodes, as the kernel doesn't report oom_kill events recursively currently, and
* we also don't want to generate a log message for each parent cgroup of a process. */
if (u->type == UNIT_SLICE)
return 0;
if (u->cgroup_memory_inotify_wd >= 0)
return 0;
/* Only applies to the unified hierarchy */
r = cg_all_unified();
if (r < 0)
return log_error_errno(r, "Failed to determine whether the memory controller is unified: %m");
if (r == 0)
return 0;
r = hashmap_ensure_allocated(&u->manager->cgroup_memory_inotify_wd_unit, &trivial_hash_ops);
if (r < 0)
return log_oom();
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "memory.events", &events);
if (r < 0)
return log_oom();
u->cgroup_memory_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY);
if (u->cgroup_memory_inotify_wd < 0) {
if (errno == ENOENT) /* If the directory is already gone we don't need to track it, so this
* is not an error */
return 0;
return log_unit_error_errno(u, errno, "Failed to add memory inotify watch descriptor for control group %s: %m", u->cgroup_path);
}
r = hashmap_put(u->manager->cgroup_memory_inotify_wd_unit, INT_TO_PTR(u->cgroup_memory_inotify_wd), u);
if (r < 0)
return log_unit_error_errno(u, r, "Failed to add memory inotify watch descriptor to hash map: %m");
return 0;
}
int unit_pick_cgroup_path(Unit *u) {
_cleanup_free_ char *path = NULL;
int r;
assert(u);
if (u->cgroup_path)
return 0;
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return -EINVAL;
path = unit_default_cgroup_path(u);
if (!path)
return log_oom();
r = unit_set_cgroup_path(u, path);
if (r == -EEXIST)
return log_unit_error_errno(u, r, "Control group %s exists already.", path);
if (r < 0)
return log_unit_error_errno(u, r, "Failed to set unit's control group path to %s: %m", path);
return 0;
}
static int unit_create_cgroup(
Unit *u,
CGroupMask target_mask,
CGroupMask enable_mask,
ManagerState state) {
bool created;
int r;
assert(u);
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return 0;
/* Figure out our cgroup path */
r = unit_pick_cgroup_path(u);
if (r < 0)
return r;
/* First, create our own group */
r = cg_create_everywhere(u->manager->cgroup_supported, target_mask, u->cgroup_path);
if (r < 0)
return log_unit_error_errno(u, r, "Failed to create cgroup %s: %m", u->cgroup_path);
created = r;
/* Start watching it */
(void) unit_watch_cgroup(u);
(void) unit_watch_cgroup_memory(u);
/* Preserve enabled controllers in delegated units, adjust others. */
if (created || !u->cgroup_realized || !unit_cgroup_delegate(u)) {
CGroupMask result_mask = 0;
/* Enable all controllers we need */
r = cg_enable_everywhere(u->manager->cgroup_supported, enable_mask, u->cgroup_path, &result_mask);
if (r < 0)
log_unit_warning_errno(u, r, "Failed to enable/disable controllers on cgroup %s, ignoring: %m", u->cgroup_path);
/* If we just turned off a controller, this might release the controller for our parent too, let's
* enqueue the parent for re-realization in that case again. */
if (UNIT_ISSET(u->slice)) {
CGroupMask turned_off;
turned_off = (u->cgroup_realized ? u->cgroup_enabled_mask & ~result_mask : 0);
if (turned_off != 0) {
Unit *parent;
/* Force the parent to propagate the enable mask to the kernel again, by invalidating
* the controller we just turned off. */
for (parent = UNIT_DEREF(u->slice); parent; parent = UNIT_DEREF(parent->slice))
unit_invalidate_cgroup(parent, turned_off);
}
}
/* Remember what's actually enabled now */
u->cgroup_enabled_mask = result_mask;
}
/* Keep track that this is now realized */
u->cgroup_realized = true;
u->cgroup_realized_mask = target_mask;
if (u->type != UNIT_SLICE && !unit_cgroup_delegate(u)) {
/* Then, possibly move things over, but not if
* subgroups may contain processes, which is the case
* for slice and delegation units. */
r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, u->cgroup_path, migrate_callback, u);
if (r < 0)
log_unit_warning_errno(u, r, "Failed to migrate cgroup from to %s, ignoring: %m", u->cgroup_path);
}
/* Set attributes */
cgroup_context_apply(u, target_mask, state);
cgroup_xattr_apply(u);
return 0;
}
static int unit_attach_pid_to_cgroup_via_bus(Unit *u, pid_t pid, const char *suffix_path) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
char *pp;
int r;
assert(u);
if (MANAGER_IS_SYSTEM(u->manager))
return -EINVAL;
if (!u->manager->system_bus)
return -EIO;
if (!u->cgroup_path)
return -EINVAL;
/* Determine this unit's cgroup path relative to our cgroup root */
pp = path_startswith(u->cgroup_path, u->manager->cgroup_root);
if (!pp)
return -EINVAL;
pp = strjoina("/", pp, suffix_path);
path_simplify(pp, false);
r = sd_bus_call_method(u->manager->system_bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"AttachProcessesToUnit",
&error, NULL,
"ssau",
NULL /* empty unit name means client's unit, i.e. us */, pp, 1, (uint32_t) pid);
if (r < 0)
return log_unit_debug_errno(u, r, "Failed to attach unit process " PID_FMT " via the bus: %s", pid, bus_error_message(&error, r));
return 0;
}
int unit_attach_pids_to_cgroup(Unit *u, Set *pids, const char *suffix_path) {
CGroupMask delegated_mask;
const char *p;
Iterator i;
void *pidp;
int r, q;
assert(u);
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return -EINVAL;
if (set_isempty(pids))
return 0;
/* Load any custom firewall BPF programs here once to test if they are existing and actually loadable.
* Fail here early since later errors in the call chain unit_realize_cgroup to cgroup_context_apply are ignored. */
r = bpf_firewall_load_custom(u);
if (r < 0)
return r;
r = unit_realize_cgroup(u);
if (r < 0)
return r;
if (isempty(suffix_path))
p = u->cgroup_path;
else
p = prefix_roota(u->cgroup_path, suffix_path);
delegated_mask = unit_get_delegate_mask(u);
r = 0;
SET_FOREACH(pidp, pids, i) {
pid_t pid = PTR_TO_PID(pidp);
CGroupController c;
/* First, attach the PID to the main cgroup hierarchy */
q = cg_attach(SYSTEMD_CGROUP_CONTROLLER, p, pid);
if (q < 0) {
log_unit_debug_errno(u, q, "Couldn't move process " PID_FMT " to requested cgroup '%s': %m", pid, p);
if (MANAGER_IS_USER(u->manager) && IN_SET(q, -EPERM, -EACCES)) {
int z;
/* If we are in a user instance, and we can't move the process ourselves due to
* permission problems, let's ask the system instance about it instead. Since it's more
* privileged it might be able to move the process across the leaves of a subtree who's
* top node is not owned by us. */
z = unit_attach_pid_to_cgroup_via_bus(u, pid, suffix_path);
if (z < 0)
log_unit_debug_errno(u, z, "Couldn't move process " PID_FMT " to requested cgroup '%s' via the system bus either: %m", pid, p);
else
continue; /* When the bus thing worked via the bus we are fully done for this PID. */
}
if (r >= 0)
r = q; /* Remember first error */
continue;
}
q = cg_all_unified();
if (q < 0)
return q;
if (q > 0)
continue;
/* In the legacy hierarchy, attach the process to the request cgroup if possible, and if not to the
* innermost realized one */
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
const char *realized;
if (!(u->manager->cgroup_supported & bit))
continue;
/* If this controller is delegated and realized, honour the caller's request for the cgroup suffix. */
if (delegated_mask & u->cgroup_realized_mask & bit) {
q = cg_attach(cgroup_controller_to_string(c), p, pid);
if (q >= 0)
continue; /* Success! */
log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to requested cgroup %s in controller %s, falling back to unit's cgroup: %m",
pid, p, cgroup_controller_to_string(c));
}
/* So this controller is either not delegate or realized, or something else weird happened. In
* that case let's attach the PID at least to the closest cgroup up the tree that is
* realized. */
realized = unit_get_realized_cgroup_path(u, bit);
if (!realized)
continue; /* Not even realized in the root slice? Then let's not bother */
q = cg_attach(cgroup_controller_to_string(c), realized, pid);
if (q < 0)
log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to realized cgroup %s in controller %s, ignoring: %m",
pid, realized, cgroup_controller_to_string(c));
}
}
return r;
}
static bool unit_has_mask_realized(
Unit *u,
CGroupMask target_mask,
CGroupMask enable_mask) {
assert(u);
/* Returns true if this unit is fully realized. We check four things:
*
* 1. Whether the cgroup was created at all
* 2. Whether the cgroup was created in all the hierarchies we need it to be created in (in case of cgroup v1)
* 3. Whether the cgroup has all the right controllers enabled (in case of cgroup v2)
* 4. Whether the invalidation mask is currently zero
*
* If you wonder why we mask the target realization and enable mask with CGROUP_MASK_V1/CGROUP_MASK_V2: note
* that there are three sets of bitmasks: CGROUP_MASK_V1 (for real cgroup v1 controllers), CGROUP_MASK_V2 (for
* real cgroup v2 controllers) and CGROUP_MASK_BPF (for BPF-based pseudo-controllers). Now, cgroup_realized_mask
* is only matters for cgroup v1 controllers, and cgroup_enabled_mask only used for cgroup v2, and if they
* differ in the others, we don't really care. (After all, the cgroup_enabled_mask tracks with controllers are
* enabled through cgroup.subtree_control, and since the BPF pseudo-controllers don't show up there, they
* simply don't matter. */
return u->cgroup_realized &&
((u->cgroup_realized_mask ^ target_mask) & CGROUP_MASK_V1) == 0 &&
((u->cgroup_enabled_mask ^ enable_mask) & CGROUP_MASK_V2) == 0 &&
u->cgroup_invalidated_mask == 0;
}
static bool unit_has_mask_disables_realized(
Unit *u,
CGroupMask target_mask,
CGroupMask enable_mask) {
assert(u);
/* Returns true if all controllers which should be disabled are indeed disabled.
*
* Unlike unit_has_mask_realized, we don't care what was enabled, only that anything we want to remove is
* already removed. */
return !u->cgroup_realized ||
(FLAGS_SET(u->cgroup_realized_mask, target_mask & CGROUP_MASK_V1) &&
FLAGS_SET(u->cgroup_enabled_mask, enable_mask & CGROUP_MASK_V2));
}
static bool unit_has_mask_enables_realized(
Unit *u,
CGroupMask target_mask,
CGroupMask enable_mask) {
assert(u);
/* Returns true if all controllers which should be enabled are indeed enabled.
*
* Unlike unit_has_mask_realized, we don't care about the controllers that are not present, only that anything
* we want to add is already added. */
return u->cgroup_realized &&
((u->cgroup_realized_mask | target_mask) & CGROUP_MASK_V1) == (u->cgroup_realized_mask & CGROUP_MASK_V1) &&
((u->cgroup_enabled_mask | enable_mask) & CGROUP_MASK_V2) == (u->cgroup_enabled_mask & CGROUP_MASK_V2);
}
void unit_add_to_cgroup_realize_queue(Unit *u) {
assert(u);
if (u->in_cgroup_realize_queue)
return;
LIST_PREPEND(cgroup_realize_queue, u->manager->cgroup_realize_queue, u);
u->in_cgroup_realize_queue = true;
}
static void unit_remove_from_cgroup_realize_queue(Unit *u) {
assert(u);
if (!u->in_cgroup_realize_queue)
return;
LIST_REMOVE(cgroup_realize_queue, u->manager->cgroup_realize_queue, u);
u->in_cgroup_realize_queue = false;
}
/* Controllers can only be enabled breadth-first, from the root of the
* hierarchy downwards to the unit in question. */
static int unit_realize_cgroup_now_enable(Unit *u, ManagerState state) {
CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask;
int r;
assert(u);
/* First go deal with this unit's parent, or we won't be able to enable
* any new controllers at this layer. */
if (UNIT_ISSET(u->slice)) {
r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->slice), state);
if (r < 0)
return r;
}
target_mask = unit_get_target_mask(u);
enable_mask = unit_get_enable_mask(u);
/* We can only enable in this direction, don't try to disable anything.
*/
if (unit_has_mask_enables_realized(u, target_mask, enable_mask))
return 0;
new_target_mask = u->cgroup_realized_mask | target_mask;
new_enable_mask = u->cgroup_enabled_mask | enable_mask;
return unit_create_cgroup(u, new_target_mask, new_enable_mask, state);
}
/* Controllers can only be disabled depth-first, from the leaves of the
* hierarchy upwards to the unit in question. */
static int unit_realize_cgroup_now_disable(Unit *u, ManagerState state) {
Iterator i;
Unit *m;
void *v;
assert(u);
if (u->type != UNIT_SLICE)
return 0;
HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) {
CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask;
int r;
if (UNIT_DEREF(m->slice) != u)
continue;
/* The cgroup for this unit might not actually be fully
* realised yet, in which case it isn't holding any controllers
* open anyway. */
if (!m->cgroup_path)
continue;
/* We must disable those below us first in order to release the
* controller. */
if (m->type == UNIT_SLICE)
(void) unit_realize_cgroup_now_disable(m, state);
target_mask = unit_get_target_mask(m);
enable_mask = unit_get_enable_mask(m);
/* We can only disable in this direction, don't try to enable
* anything. */
if (unit_has_mask_disables_realized(m, target_mask, enable_mask))
continue;
new_target_mask = m->cgroup_realized_mask & target_mask;
new_enable_mask = m->cgroup_enabled_mask & enable_mask;
r = unit_create_cgroup(m, new_target_mask, new_enable_mask, state);
if (r < 0)
return r;
}
return 0;
}
/* Check if necessary controllers and attributes for a unit are in place.
*
* - If so, do nothing.
* - If not, create paths, move processes over, and set attributes.
*
* Controllers can only be *enabled* in a breadth-first way, and *disabled* in
* a depth-first way. As such the process looks like this:
*
* Suppose we have a cgroup hierarchy which looks like this:
*
* root
* / \
* / \
* / \
* a b
* / \ / \
* / \ / \
* c d e f
* / \ / \ / \ / \
* h i j k l m n o
*
* 1. We want to realise cgroup "d" now.
* 2. cgroup "a" has DisableControllers=cpu in the associated unit.
* 3. cgroup "k" just started requesting the memory controller.
*
* To make this work we must do the following in order:
*
* 1. Disable CPU controller in k, j
* 2. Disable CPU controller in d
* 3. Enable memory controller in root
* 4. Enable memory controller in a
* 5. Enable memory controller in d
* 6. Enable memory controller in k
*
* Notice that we need to touch j in one direction, but not the other. We also
* don't go beyond d when disabling -- it's up to "a" to get realized if it
* wants to disable further. The basic rules are therefore:
*
* - If you're disabling something, you need to realise all of the cgroups from
* your recursive descendants to the root. This starts from the leaves.
* - If you're enabling something, you need to realise from the root cgroup
* downwards, but you don't need to iterate your recursive descendants.
*
* Returns 0 on success and < 0 on failure. */
static int unit_realize_cgroup_now(Unit *u, ManagerState state) {
CGroupMask target_mask, enable_mask;
int r;
assert(u);
unit_remove_from_cgroup_realize_queue(u);
target_mask = unit_get_target_mask(u);
enable_mask = unit_get_enable_mask(u);
if (unit_has_mask_realized(u, target_mask, enable_mask))
return 0;
/* Disable controllers below us, if there are any */
r = unit_realize_cgroup_now_disable(u, state);
if (r < 0)
return r;
/* Enable controllers above us, if there are any */
if (UNIT_ISSET(u->slice)) {
r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->slice), state);
if (r < 0)
return r;
}
/* Now actually deal with the cgroup we were trying to realise and set attributes */
r = unit_create_cgroup(u, target_mask, enable_mask, state);
if (r < 0)
return r;
/* Now, reset the invalidation mask */
u->cgroup_invalidated_mask = 0;
return 0;
}
unsigned manager_dispatch_cgroup_realize_queue(Manager *m) {
ManagerState state;
unsigned n = 0;
Unit *i;
int r;
assert(m);
state = manager_state(m);
while ((i = m->cgroup_realize_queue)) {
assert(i->in_cgroup_realize_queue);
if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(i))) {
/* Maybe things changed, and the unit is not actually active anymore? */
unit_remove_from_cgroup_realize_queue(i);
continue;
}
r = unit_realize_cgroup_now(i, state);
if (r < 0)
log_warning_errno(r, "Failed to realize cgroups for queued unit %s, ignoring: %m", i->id);
n++;
}
return n;
}
static void unit_add_siblings_to_cgroup_realize_queue(Unit *u) {
Unit *slice;
/* This adds the siblings of the specified unit and the
* siblings of all parent units to the cgroup queue. (But
* neither the specified unit itself nor the parents.) */
while ((slice = UNIT_DEREF(u->slice))) {
Iterator i;
Unit *m;
void *v;
HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) {
/* Skip units that have a dependency on the slice
* but aren't actually in it. */
if (UNIT_DEREF(m->slice) != slice)
continue;
/* No point in doing cgroup application for units
* without active processes. */
if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m)))
continue;
/* If the unit doesn't need any new controllers
* and has current ones realized, it doesn't need
* any changes. */
if (unit_has_mask_realized(m,
unit_get_target_mask(m),
unit_get_enable_mask(m)))
continue;
unit_add_to_cgroup_realize_queue(m);
}
u = slice;
}
}
int unit_realize_cgroup(Unit *u) {
assert(u);
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return 0;
/* So, here's the deal: when realizing the cgroups for this
* unit, we need to first create all parents, but there's more
* actually: for the weight-based controllers we also need to
* make sure that all our siblings (i.e. units that are in the
* same slice as we are) have cgroups, too. Otherwise, things
* would become very uneven as each of their processes would
* get as much resources as all our group together. This call
* will synchronously create the parent cgroups, but will
* defer work on the siblings to the next event loop
* iteration. */
/* Add all sibling slices to the cgroup queue. */
unit_add_siblings_to_cgroup_realize_queue(u);
/* And realize this one now (and apply the values) */
return unit_realize_cgroup_now(u, manager_state(u->manager));
}
void unit_release_cgroup(Unit *u) {
assert(u);
/* Forgets all cgroup details for this cgroup — but does *not* destroy the cgroup. This is hence OK to call
* when we close down everything for reexecution, where we really want to leave the cgroup in place. */
if (u->cgroup_path) {
(void) hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
u->cgroup_path = mfree(u->cgroup_path);
}
if (u->cgroup_control_inotify_wd >= 0) {
if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_control_inotify_wd) < 0)
log_unit_debug_errno(u, errno, "Failed to remove cgroup control inotify watch %i for %s, ignoring: %m", u->cgroup_control_inotify_wd, u->id);
(void) hashmap_remove(u->manager->cgroup_control_inotify_wd_unit, INT_TO_PTR(u->cgroup_control_inotify_wd));
u->cgroup_control_inotify_wd = -1;
}
if (u->cgroup_memory_inotify_wd >= 0) {
if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_memory_inotify_wd) < 0)
log_unit_debug_errno(u, errno, "Failed to remove cgroup memory inotify watch %i for %s, ignoring: %m", u->cgroup_memory_inotify_wd, u->id);
(void) hashmap_remove(u->manager->cgroup_memory_inotify_wd_unit, INT_TO_PTR(u->cgroup_memory_inotify_wd));
u->cgroup_memory_inotify_wd = -1;
}
}
void unit_prune_cgroup(Unit *u) {
int r;
bool is_root_slice;
assert(u);
/* Removes the cgroup, if empty and possible, and stops watching it. */
if (!u->cgroup_path)
return;
(void) unit_get_cpu_usage(u, NULL); /* Cache the last CPU usage value before we destroy the cgroup */
is_root_slice = unit_has_name(u, SPECIAL_ROOT_SLICE);
r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !is_root_slice);
if (r < 0)
/* One reason we could have failed here is, that the cgroup still contains a process.
* However, if the cgroup becomes removable at a later time, it might be removed when
* the containing slice is stopped. So even if we failed now, this unit shouldn't assume
* that the cgroup is still realized the next time it is started. Do not return early
* on error, continue cleanup. */
log_unit_full(u, r == -EBUSY ? LOG_DEBUG : LOG_WARNING, r, "Failed to destroy cgroup %s, ignoring: %m", u->cgroup_path);
if (is_root_slice)
return;
unit_release_cgroup(u);
u->cgroup_realized = false;
u->cgroup_realized_mask = 0;
u->cgroup_enabled_mask = 0;
u->bpf_device_control_installed = bpf_program_unref(u->bpf_device_control_installed);
}
int unit_search_main_pid(Unit *u, pid_t *ret) {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0, npid;
int r;
assert(u);
assert(ret);
if (!u->cgroup_path)
return -ENXIO;
r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f);
if (r < 0)
return r;
while (cg_read_pid(f, &npid) > 0) {
if (npid == pid)
continue;
if (pid_is_my_child(npid) == 0)
continue;
if (pid != 0)
/* Dang, there's more than one daemonized PID
in this group, so we don't know what process
is the main process. */
return -ENODATA;
pid = npid;
}
*ret = pid;
return 0;
}
static int unit_watch_pids_in_path(Unit *u, const char *path) {
_cleanup_closedir_ DIR *d = NULL;
_cleanup_fclose_ FILE *f = NULL;
int ret = 0, r;
assert(u);
assert(path);
r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, path, &f);
if (r < 0)
ret = r;
else {
pid_t pid;
while ((r = cg_read_pid(f, &pid)) > 0) {
r = unit_watch_pid(u, pid, false);
if (r < 0 && ret >= 0)
ret = r;
}
if (r < 0 && ret >= 0)
ret = r;
}
r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d);
if (r < 0) {
if (ret >= 0)
ret = r;
} else {
char *fn;
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 = unit_watch_pids_in_path(u, p);
if (r < 0 && ret >= 0)
ret = r;
}
if (r < 0 && ret >= 0)
ret = r;
}
return ret;
}
int unit_synthesize_cgroup_empty_event(Unit *u) {
int r;
assert(u);
/* Enqueue a synthetic cgroup empty event if this unit doesn't watch any PIDs anymore. This is compatibility
* support for non-unified systems where notifications aren't reliable, and hence need to take whatever we can
* get as notification source as soon as we stopped having any useful PIDs to watch for. */
if (!u->cgroup_path)
return -ENOENT;
r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
if (r < 0)
return r;
if (r > 0) /* On unified we have reliable notifications, and don't need this */
return 0;
if (!set_isempty(u->pids))
return 0;
unit_add_to_cgroup_empty_queue(u);
return 0;
}
int unit_watch_all_pids(Unit *u) {
int r;
assert(u);
/* Adds all PIDs from our cgroup to the set of PIDs we
* watch. This is a fallback logic for cases where we do not
* get reliable cgroup empty notifications: we try to use
* SIGCHLD as replacement. */
if (!u->cgroup_path)
return -ENOENT;
r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
if (r < 0)
return r;
if (r > 0) /* On unified we can use proper notifications */
return 0;
return unit_watch_pids_in_path(u, u->cgroup_path);
}
static int on_cgroup_empty_event(sd_event_source *s, void *userdata) {
Manager *m = userdata;
Unit *u;
int r;
assert(s);
assert(m);
u = m->cgroup_empty_queue;
if (!u)
return 0;
assert(u->in_cgroup_empty_queue);
u->in_cgroup_empty_queue = false;
LIST_REMOVE(cgroup_empty_queue, m->cgroup_empty_queue, u);
if (m->cgroup_empty_queue) {
/* More stuff queued, let's make sure we remain enabled */
r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
if (r < 0)
log_debug_errno(r, "Failed to reenable cgroup empty event source, ignoring: %m");
}
unit_add_to_gc_queue(u);
if (UNIT_VTABLE(u)->notify_cgroup_empty)
UNIT_VTABLE(u)->notify_cgroup_empty(u);
return 0;
}
void unit_add_to_cgroup_empty_queue(Unit *u) {
int r;
assert(u);
/* Note that there are four different ways how cgroup empty events reach us:
*
* 1. On the unified hierarchy we get an inotify event on the cgroup
*
* 2. On the legacy hierarchy, when running in system mode, we get a datagram on the cgroup agent socket
*
* 3. On the legacy hierarchy, when running in user mode, we get a D-Bus signal on the system bus
*
* 4. On the legacy hierarchy, in service units we start watching all processes of the cgroup for SIGCHLD as
* soon as we get one SIGCHLD, to deal with unreliable cgroup notifications.
*
* Regardless which way we got the notification, we'll verify it here, and then add it to a separate
* queue. This queue will be dispatched at a lower priority than the SIGCHLD handler, so that we always use
* SIGCHLD if we can get it first, and only use the cgroup empty notifications if there's no SIGCHLD pending
* (which might happen if the cgroup doesn't contain processes that are our own child, which is typically the
* case for scope units). */
if (u->in_cgroup_empty_queue)
return;
/* Let's verify that the cgroup is really empty */
if (!u->cgroup_path)
return;
r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path);
if (r < 0) {
log_unit_debug_errno(u, r, "Failed to determine whether cgroup %s is empty: %m", u->cgroup_path);
return;
}
if (r == 0)
return;
LIST_PREPEND(cgroup_empty_queue, u->manager->cgroup_empty_queue, u);
u->in_cgroup_empty_queue = true;
/* Trigger the defer event */
r = sd_event_source_set_enabled(u->manager->cgroup_empty_event_source, SD_EVENT_ONESHOT);
if (r < 0)
log_debug_errno(r, "Failed to enable cgroup empty event source: %m");
}
int unit_check_oom(Unit *u) {
_cleanup_free_ char *oom_kill = NULL;
bool increased;
uint64_t c;
int r;
if (!u->cgroup_path)
return 0;
r = cg_get_keyed_attribute("memory", u->cgroup_path, "memory.events", STRV_MAKE("oom_kill"), &oom_kill);
if (r < 0)
return log_unit_debug_errno(u, r, "Failed to read oom_kill field of memory.events cgroup attribute: %m");
r = safe_atou64(oom_kill, &c);
if (r < 0)
return log_unit_debug_errno(u, r, "Failed to parse oom_kill field: %m");
increased = c > u->oom_kill_last;
u->oom_kill_last = c;
if (!increased)
return 0;
log_struct(LOG_NOTICE,
"MESSAGE_ID=" SD_MESSAGE_UNIT_OUT_OF_MEMORY_STR,
LOG_UNIT_ID(u),
LOG_UNIT_INVOCATION_ID(u),
LOG_UNIT_MESSAGE(u, "A process of this unit has been killed by the OOM killer."));
if (UNIT_VTABLE(u)->notify_cgroup_oom)
UNIT_VTABLE(u)->notify_cgroup_oom(u);
return 1;
}
static int on_cgroup_oom_event(sd_event_source *s, void *userdata) {
Manager *m = userdata;
Unit *u;
int r;
assert(s);
assert(m);
u = m->cgroup_oom_queue;
if (!u)
return 0;
assert(u->in_cgroup_oom_queue);
u->in_cgroup_oom_queue = false;
LIST_REMOVE(cgroup_oom_queue, m->cgroup_oom_queue, u);
if (m->cgroup_oom_queue) {
/* More stuff queued, let's make sure we remain enabled */
r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
if (r < 0)
log_debug_errno(r, "Failed to reenable cgroup oom event source, ignoring: %m");
}
(void) unit_check_oom(u);
return 0;
}
static void unit_add_to_cgroup_oom_queue(Unit *u) {
int r;
assert(u);
if (u->in_cgroup_oom_queue)
return;
if (!u->cgroup_path)
return;
LIST_PREPEND(cgroup_oom_queue, u->manager->cgroup_oom_queue, u);
u->in_cgroup_oom_queue = true;
/* Trigger the defer event */
if (!u->manager->cgroup_oom_event_source) {
_cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
r = sd_event_add_defer(u->manager->event, &s, on_cgroup_oom_event, u->manager);
if (r < 0) {
log_error_errno(r, "Failed to create cgroup oom event source: %m");
return;
}
r = sd_event_source_set_priority(s, SD_EVENT_PRIORITY_NORMAL-8);
if (r < 0) {
log_error_errno(r, "Failed to set priority of cgroup oom event source: %m");
return;
}
(void) sd_event_source_set_description(s, "cgroup-oom");
u->manager->cgroup_oom_event_source = TAKE_PTR(s);
}
r = sd_event_source_set_enabled(u->manager->cgroup_oom_event_source, SD_EVENT_ONESHOT);
if (r < 0)
log_error_errno(r, "Failed to enable cgroup oom event source: %m");
}
static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
Manager *m = userdata;
assert(s);
assert(fd >= 0);
assert(m);
for (;;) {
union inotify_event_buffer buffer;
struct inotify_event *e;
ssize_t l;
l = read(fd, &buffer, sizeof(buffer));
if (l < 0) {
if (IN_SET(errno, EINTR, EAGAIN))
return 0;
return log_error_errno(errno, "Failed to read control group inotify events: %m");
}
FOREACH_INOTIFY_EVENT(e, buffer, l) {
Unit *u;
if (e->wd < 0)
/* Queue overflow has no watch descriptor */
continue;
if (e->mask & IN_IGNORED)
/* The watch was just removed */
continue;
/* Note that inotify might deliver events for a watch even after it was removed,
* because it was queued before the removal. Let's ignore this here safely. */
u = hashmap_get(m->cgroup_control_inotify_wd_unit, INT_TO_PTR(e->wd));
if (u)
unit_add_to_cgroup_empty_queue(u);
u = hashmap_get(m->cgroup_memory_inotify_wd_unit, INT_TO_PTR(e->wd));
if (u)
unit_add_to_cgroup_oom_queue(u);
}
}
}
static int cg_bpf_mask_supported(CGroupMask *ret) {
CGroupMask mask = 0;
int r;
/* BPF-based firewall */
r = bpf_firewall_supported();
if (r > 0)
mask |= CGROUP_MASK_BPF_FIREWALL;
/* BPF-based device access control */
r = bpf_devices_supported();
if (r > 0)
mask |= CGROUP_MASK_BPF_DEVICES;
*ret = mask;
return 0;
}
int manager_setup_cgroup(Manager *m) {
_cleanup_free_ char *path = NULL;
const char *scope_path;
CGroupController c;
int r, all_unified;
CGroupMask mask;
char *e;
assert(m);
/* 1. Determine hierarchy */
m->cgroup_root = mfree(m->cgroup_root);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root);
if (r < 0)
return log_error_errno(r, "Cannot determine cgroup we are running in: %m");
/* Chop off the init scope, if we are already located in it */
e = endswith(m->cgroup_root, "/" SPECIAL_INIT_SCOPE);
/* LEGACY: Also chop off the system slice if we are in
* it. This is to support live upgrades from older systemd
* versions where PID 1 was moved there. Also see
* cg_get_root_path(). */
if (!e && MANAGER_IS_SYSTEM(m)) {
e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE);
if (!e)
e = endswith(m->cgroup_root, "/system"); /* even more legacy */
}
if (e)
*e = 0;
/* And make sure to store away the root value without trailing slash, even for the root dir, so that we can
* easily prepend it everywhere. */
delete_trailing_chars(m->cgroup_root, "/");
/* 2. Show data */
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path);
if (r < 0)
return log_error_errno(r, "Cannot find cgroup mount point: %m");
r = cg_unified_flush();
if (r < 0)
return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m");
all_unified = cg_all_unified();
if (all_unified < 0)
return log_error_errno(all_unified, "Couldn't determine whether we are in all unified mode: %m");
if (all_unified > 0)
log_debug("Unified cgroup hierarchy is located at %s.", path);
else {
r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
if (r < 0)
return log_error_errno(r, "Failed to determine whether systemd's own controller is in unified mode: %m");
if (r > 0)
log_debug("Unified cgroup hierarchy is located at %s. Controllers are on legacy hierarchies.", path);
else
log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER_LEGACY ". File system hierarchy is at %s.", path);
}
/* 3. Allocate cgroup empty defer event source */
m->cgroup_empty_event_source = sd_event_source_unref(m->cgroup_empty_event_source);
r = sd_event_add_defer(m->event, &m->cgroup_empty_event_source, on_cgroup_empty_event, m);
if (r < 0)
return log_error_errno(r, "Failed to create cgroup empty event source: %m");
/* Schedule cgroup empty checks early, but after having processed service notification messages or
* SIGCHLD signals, so that a cgroup running empty is always just the last safety net of
* notification, and we collected the metadata the notification and SIGCHLD stuff offers first. */
r = sd_event_source_set_priority(m->cgroup_empty_event_source, SD_EVENT_PRIORITY_NORMAL-5);
if (r < 0)
return log_error_errno(r, "Failed to set priority of cgroup empty event source: %m");
r = sd_event_source_set_enabled(m->cgroup_empty_event_source, SD_EVENT_OFF);
if (r < 0)
return log_error_errno(r, "Failed to disable cgroup empty event source: %m");
(void) sd_event_source_set_description(m->cgroup_empty_event_source, "cgroup-empty");
/* 4. Install notifier inotify object, or agent */
if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) {
/* In the unified hierarchy we can get cgroup empty notifications via inotify. */
m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source);
safe_close(m->cgroup_inotify_fd);
m->cgroup_inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
if (m->cgroup_inotify_fd < 0)
return log_error_errno(errno, "Failed to create control group inotify object: %m");
r = sd_event_add_io(m->event, &m->cgroup_inotify_event_source, m->cgroup_inotify_fd, EPOLLIN, on_cgroup_inotify_event, m);
if (r < 0)
return log_error_errno(r, "Failed to watch control group inotify object: %m");
/* Process cgroup empty notifications early. Note that when this event is dispatched it'll
* just add the unit to a cgroup empty queue, hence let's run earlier than that. Also see
* handling of cgroup agent notifications, for the classic cgroup hierarchy support. */
r = sd_event_source_set_priority(m->cgroup_inotify_event_source, SD_EVENT_PRIORITY_NORMAL-9);
if (r < 0)
return log_error_errno(r, "Failed to set priority of inotify event source: %m");
(void) sd_event_source_set_description(m->cgroup_inotify_event_source, "cgroup-inotify");
} else if (MANAGER_IS_SYSTEM(m) && manager_owns_host_root_cgroup(m) && !MANAGER_IS_TEST_RUN(m)) {
/* On the legacy hierarchy we only get notifications via cgroup agents. (Which isn't really reliable,
* since it does not generate events when control groups with children run empty. */
r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUP_AGENT_PATH);
if (r < 0)
log_warning_errno(r, "Failed to install release agent, ignoring: %m");
else if (r > 0)
log_debug("Installed release agent.");
else if (r == 0)
log_debug("Release agent already installed.");
}
/* 5. Make sure we are in the special "init.scope" unit in the root slice. */
scope_path = strjoina(m->cgroup_root, "/" SPECIAL_INIT_SCOPE);
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, scope_path, 0);
if (r >= 0) {
/* Also, move all other userspace processes remaining in the root cgroup into that scope. */
r = cg_migrate(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, SYSTEMD_CGROUP_CONTROLLER, scope_path, 0);
if (r < 0)
log_warning_errno(r, "Couldn't move remaining userspace processes, ignoring: %m");
/* 6. And pin it, so that it cannot be unmounted */
safe_close(m->pin_cgroupfs_fd);
m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
if (m->pin_cgroupfs_fd < 0)
return log_error_errno(errno, "Failed to open pin file: %m");
} else if (!MANAGER_IS_TEST_RUN(m))
return log_error_errno(r, "Failed to create %s control group: %m", scope_path);
/* 7. Always enable hierarchical support if it exists... */
if (!all_unified && !MANAGER_IS_TEST_RUN(m))
(void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
/* 8. Figure out which controllers are supported */
r = cg_mask_supported(&m->cgroup_supported);
if (r < 0)
return log_error_errno(r, "Failed to determine supported controllers: %m");
/* 9. Figure out which bpf-based pseudo-controllers are supported */
r = cg_bpf_mask_supported(&mask);
if (r < 0)
return log_error_errno(r, "Failed to determine supported bpf-based pseudo-controllers: %m");
m->cgroup_supported |= mask;
/* 10. Log which controllers are supported */
for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++)
log_debug("Controller '%s' supported: %s", cgroup_controller_to_string(c), yes_no(m->cgroup_supported & CGROUP_CONTROLLER_TO_MASK(c)));
return 0;
}
void manager_shutdown_cgroup(Manager *m, bool delete) {
assert(m);
/* We can't really delete the group, since we are in it. But
* let's trim it. */
if (delete && m->cgroup_root && m->test_run_flags != MANAGER_TEST_RUN_MINIMAL)
(void) cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false);
m->cgroup_empty_event_source = sd_event_source_unref(m->cgroup_empty_event_source);
m->cgroup_control_inotify_wd_unit = hashmap_free(m->cgroup_control_inotify_wd_unit);
m->cgroup_memory_inotify_wd_unit = hashmap_free(m->cgroup_memory_inotify_wd_unit);
m->cgroup_inotify_event_source = sd_event_source_unref(m->cgroup_inotify_event_source);
m->cgroup_inotify_fd = safe_close(m->cgroup_inotify_fd);
m->pin_cgroupfs_fd = safe_close(m->pin_cgroupfs_fd);
m->cgroup_root = mfree(m->cgroup_root);
}
Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
char *p;
Unit *u;
assert(m);
assert(cgroup);
u = hashmap_get(m->cgroup_unit, cgroup);
if (u)
return u;
p = strdupa(cgroup);
for (;;) {
char *e;
e = strrchr(p, '/');
if (!e || e == p)
return hashmap_get(m->cgroup_unit, SPECIAL_ROOT_SLICE);
*e = 0;
u = hashmap_get(m->cgroup_unit, p);
if (u)
return u;
}
}
Unit *manager_get_unit_by_pid_cgroup(Manager *m, pid_t pid) {
_cleanup_free_ char *cgroup = NULL;
assert(m);
if (!pid_is_valid(pid))
return NULL;
if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup) < 0)
return NULL;
return manager_get_unit_by_cgroup(m, cgroup);
}
Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
Unit *u, **array;
assert(m);
/* Note that a process might be owned by multiple units, we return only one here, which is good enough for most
* cases, though not strictly correct. We prefer the one reported by cgroup membership, as that's the most
* relevant one as children of the process will be assigned to that one, too, before all else. */
if (!pid_is_valid(pid))
return NULL;
if (pid == getpid_cached())
return hashmap_get(m->units, SPECIAL_INIT_SCOPE);
u = manager_get_unit_by_pid_cgroup(m, pid);
if (u)
return u;
u = hashmap_get(m->watch_pids, PID_TO_PTR(pid));
if (u)
return u;
array = hashmap_get(m->watch_pids, PID_TO_PTR(-pid));
if (array)
return array[0];
return NULL;
}
int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
Unit *u;
assert(m);
assert(cgroup);
/* Called on the legacy hierarchy whenever we get an explicit cgroup notification from the cgroup agent process
* or from the --system instance */
log_debug("Got cgroup empty notification for: %s", cgroup);
u = manager_get_unit_by_cgroup(m, cgroup);
if (!u)
return 0;
unit_add_to_cgroup_empty_queue(u);
return 1;
}
int unit_get_memory_current(Unit *u, uint64_t *ret) {
_cleanup_free_ char *v = NULL;
int r;
assert(u);
assert(ret);
if (!UNIT_CGROUP_BOOL(u, memory_accounting))
return -ENODATA;
if (!u->cgroup_path)
return -ENODATA;
/* The root cgroup doesn't expose this information, let's get it from /proc instead */
if (unit_has_host_root_cgroup(u))
return procfs_memory_get_used(ret);
if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0)
return -ENODATA;
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0)
r = cg_get_attribute("memory", u->cgroup_path, "memory.current", &v);
else
r = cg_get_attribute("memory", u->cgroup_path, "memory.usage_in_bytes", &v);
if (r == -ENOENT)
return -ENODATA;
if (r < 0)
return r;
return safe_atou64(v, ret);
}
int unit_get_tasks_current(Unit *u, uint64_t *ret) {
_cleanup_free_ char *v = NULL;
int r;
assert(u);
assert(ret);
if (!UNIT_CGROUP_BOOL(u, tasks_accounting))
return -ENODATA;
if (!u->cgroup_path)
return -ENODATA;
/* The root cgroup doesn't expose this information, let's get it from /proc instead */
if (unit_has_host_root_cgroup(u))
return procfs_tasks_get_current(ret);
if ((u->cgroup_realized_mask & CGROUP_MASK_PIDS) == 0)
return -ENODATA;
r = cg_get_attribute("pids", u->cgroup_path, "pids.current", &v);
if (r == -ENOENT)
return -ENODATA;
if (r < 0)
return r;
return safe_atou64(v, ret);
}
static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) {
_cleanup_free_ char *v = NULL;
uint64_t ns;
int r;
assert(u);
assert(ret);
if (!u->cgroup_path)
return -ENODATA;
/* The root cgroup doesn't expose this information, let's get it from /proc instead */
if (unit_has_host_root_cgroup(u))
return procfs_cpu_get_usage(ret);
/* Requisite controllers for CPU accounting are not enabled */
if ((get_cpu_accounting_mask() & ~u->cgroup_realized_mask) != 0)
return -ENODATA;
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0) {
_cleanup_free_ char *val = NULL;
uint64_t us;
r = cg_get_keyed_attribute("cpu", u->cgroup_path, "cpu.stat", STRV_MAKE("usage_usec"), &val);
if (IN_SET(r, -ENOENT, -ENXIO))
return -ENODATA;
if (r < 0)
return r;
r = safe_atou64(val, &us);
if (r < 0)
return r;
ns = us * NSEC_PER_USEC;
} else {
r = cg_get_attribute("cpuacct", u->cgroup_path, "cpuacct.usage", &v);
if (r == -ENOENT)
return -ENODATA;
if (r < 0)
return r;
r = safe_atou64(v, &ns);
if (r < 0)
return r;
}
*ret = ns;
return 0;
}
int unit_get_cpu_usage(Unit *u, nsec_t *ret) {
nsec_t ns;
int r;
assert(u);
/* Retrieve the current CPU usage counter. This will subtract the CPU counter taken when the unit was
* started. If the cgroup has been removed already, returns the last cached value. To cache the value, simply
* call this function with a NULL return value. */
if (!UNIT_CGROUP_BOOL(u, cpu_accounting))
return -ENODATA;
r = unit_get_cpu_usage_raw(u, &ns);
if (r == -ENODATA && u->cpu_usage_last != NSEC_INFINITY) {
/* If we can't get the CPU usage anymore (because the cgroup was already removed, for example), use our
* cached value. */
if (ret)
*ret = u->cpu_usage_last;
return 0;
}
if (r < 0)
return r;
if (ns > u->cpu_usage_base)
ns -= u->cpu_usage_base;
else
ns = 0;
u->cpu_usage_last = ns;
if (ret)
*ret = ns;
return 0;
}
int unit_get_ip_accounting(
Unit *u,
CGroupIPAccountingMetric metric,
uint64_t *ret) {
uint64_t value;
int fd, r;
assert(u);
assert(metric >= 0);
assert(metric < _CGROUP_IP_ACCOUNTING_METRIC_MAX);
assert(ret);
if (!UNIT_CGROUP_BOOL(u, ip_accounting))
return -ENODATA;
fd = IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_INGRESS_PACKETS) ?
u->ip_accounting_ingress_map_fd :
u->ip_accounting_egress_map_fd;
if (fd < 0)
return -ENODATA;
if (IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_EGRESS_BYTES))
r = bpf_firewall_read_accounting(fd, &value, NULL);
else
r = bpf_firewall_read_accounting(fd, NULL, &value);
if (r < 0)
return r;
/* Add in additional metrics from a previous runtime. Note that when reexecing/reloading the daemon we compile
* all BPF programs and maps anew, but serialize the old counters. When deserializing we store them in the
* ip_accounting_extra[] field, and add them in here transparently. */
*ret = value + u->ip_accounting_extra[metric];
return r;
}
static int unit_get_io_accounting_raw(Unit *u, uint64_t ret[static _CGROUP_IO_ACCOUNTING_METRIC_MAX]) {
static const char *const field_names[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = {
[CGROUP_IO_READ_BYTES] = "rbytes=",
[CGROUP_IO_WRITE_BYTES] = "wbytes=",
[CGROUP_IO_READ_OPERATIONS] = "rios=",
[CGROUP_IO_WRITE_OPERATIONS] = "wios=",
};
uint64_t acc[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = {};
_cleanup_free_ char *path = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(u);
if (!u->cgroup_path)
return -ENODATA;
if (unit_has_host_root_cgroup(u))
return -ENODATA; /* TODO: return useful data for the top-level cgroup */
r = cg_all_unified();
if (r < 0)
return r;
if (r == 0) /* TODO: support cgroupv1 */
return -ENODATA;
if (!FLAGS_SET(u->cgroup_realized_mask, CGROUP_MASK_IO))
return -ENODATA;
r = cg_get_path("io", u->cgroup_path, "io.stat", &path);
if (r < 0)
return r;
f = fopen(path, "re");
if (!f)
return -errno;
for (;;) {
_cleanup_free_ char *line = NULL;
const char *p;
r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return r;
if (r == 0)
break;
p = line;
p += strcspn(p, WHITESPACE); /* Skip over device major/minor */
p += strspn(p, WHITESPACE); /* Skip over following whitespace */
for (;;) {
_cleanup_free_ char *word = NULL;
r = extract_first_word(&p, &word, NULL, EXTRACT_RETAIN_ESCAPE);
if (r < 0)
return r;
if (r == 0)
break;
for (CGroupIOAccountingMetric i = 0; i < _CGROUP_IO_ACCOUNTING_METRIC_MAX; i++) {
const char *x;
x = startswith(word, field_names[i]);
if (x) {
uint64_t w;
r = safe_atou64(x, &w);
if (r < 0)
return r;
/* Sum up the stats of all devices */
acc[i] += w;
break;
}
}
}
}
memcpy(ret, acc, sizeof(acc));
return 0;
}
int unit_get_io_accounting(
Unit *u,
CGroupIOAccountingMetric metric,
bool allow_cache,
uint64_t *ret) {
uint64_t raw[_CGROUP_IO_ACCOUNTING_METRIC_MAX];
int r;
/* Retrieve an IO account parameter. This will subtract the counter when the unit was started. */
if (!UNIT_CGROUP_BOOL(u, io_accounting))
return -ENODATA;
if (allow_cache && u->io_accounting_last[metric] != UINT64_MAX)
goto done;
r = unit_get_io_accounting_raw(u, raw);
if (r == -ENODATA && u->io_accounting_last[metric] != UINT64_MAX)
goto done;
if (r < 0)
return r;
for (CGroupIOAccountingMetric i = 0; i < _CGROUP_IO_ACCOUNTING_METRIC_MAX; i++) {
/* Saturated subtraction */
if (raw[i] > u->io_accounting_base[i])
u->io_accounting_last[i] = raw[i] - u->io_accounting_base[i];
else
u->io_accounting_last[i] = 0;
}
done:
if (ret)
*ret = u->io_accounting_last[metric];
return 0;
}
int unit_reset_cpu_accounting(Unit *u) {
int r;
assert(u);
u->cpu_usage_last = NSEC_INFINITY;
r = unit_get_cpu_usage_raw(u, &u->cpu_usage_base);
if (r < 0) {
u->cpu_usage_base = 0;
return r;
}
return 0;
}
int unit_reset_ip_accounting(Unit *u) {
int r = 0, q = 0;
assert(u);
if (u->ip_accounting_ingress_map_fd >= 0)
r = bpf_firewall_reset_accounting(u->ip_accounting_ingress_map_fd);
if (u->ip_accounting_egress_map_fd >= 0)
q = bpf_firewall_reset_accounting(u->ip_accounting_egress_map_fd);
zero(u->ip_accounting_extra);
return r < 0 ? r : q;
}
int unit_reset_io_accounting(Unit *u) {
int r;
assert(u);
for (CGroupIOAccountingMetric i = 0; i < _CGROUP_IO_ACCOUNTING_METRIC_MAX; i++)
u->io_accounting_last[i] = UINT64_MAX;
r = unit_get_io_accounting_raw(u, u->io_accounting_base);
if (r < 0) {
zero(u->io_accounting_base);
return r;
}
return 0;
}
int unit_reset_accounting(Unit *u) {
int r, q, v;
assert(u);
r = unit_reset_cpu_accounting(u);
q = unit_reset_io_accounting(u);
v = unit_reset_ip_accounting(u);
return r < 0 ? r : q < 0 ? q : v;
}
void unit_invalidate_cgroup(Unit *u, CGroupMask m) {
assert(u);
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return;
if (m == 0)
return;
/* always invalidate compat pairs together */
if (m & (CGROUP_MASK_IO | CGROUP_MASK_BLKIO))
m |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO;
if (m & (CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT))
m |= CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT;
if (FLAGS_SET(u->cgroup_invalidated_mask, m)) /* NOP? */
return;
u->cgroup_invalidated_mask |= m;
unit_add_to_cgroup_realize_queue(u);
}
void unit_invalidate_cgroup_bpf(Unit *u) {
assert(u);
if (!UNIT_HAS_CGROUP_CONTEXT(u))
return;
if (u->cgroup_invalidated_mask & CGROUP_MASK_BPF_FIREWALL) /* NOP? */
return;
u->cgroup_invalidated_mask |= CGROUP_MASK_BPF_FIREWALL;
unit_add_to_cgroup_realize_queue(u);
/* If we are a slice unit, we also need to put compile a new BPF program for all our children, as the IP access
* list of our children includes our own. */
if (u->type == UNIT_SLICE) {
Unit *member;
Iterator i;
void *v;
HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) {
if (UNIT_DEREF(member->slice) == u)
unit_invalidate_cgroup_bpf(member);
}
}
}
bool unit_cgroup_delegate(Unit *u) {
CGroupContext *c;
assert(u);
if (!UNIT_VTABLE(u)->can_delegate)
return false;
c = unit_get_cgroup_context(u);
if (!c)
return false;
return c->delegate;
}
void manager_invalidate_startup_units(Manager *m) {
Iterator i;
Unit *u;
assert(m);
SET_FOREACH(u, m->startup_units, i)
unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_BLKIO);
}
static int unit_get_nice(Unit *u) {
ExecContext *ec;
ec = unit_get_exec_context(u);
return ec ? ec->nice : 0;
}
static uint64_t unit_get_cpu_weight(Unit *u) {
ManagerState state = manager_state(u->manager);
CGroupContext *cc;
cc = unit_get_cgroup_context(u);
return cc ? cgroup_context_cpu_weight(cc, state) : CGROUP_WEIGHT_DEFAULT;
}
int compare_job_priority(const void *a, const void *b) {
const Job *x = a, *y = b;
int nice_x, nice_y;
uint64_t weight_x, weight_y;
int ret;
if ((ret = CMP(x->unit->type, y->unit->type)) != 0)
return -ret;
weight_x = unit_get_cpu_weight(x->unit);
weight_y = unit_get_cpu_weight(y->unit);
if ((ret = CMP(weight_x, weight_y)) != 0)
return -ret;
nice_x = unit_get_nice(x->unit);
nice_y = unit_get_nice(y->unit);
if ((ret = CMP(nice_x, nice_y)) != 0)
return ret;
return strcmp(x->unit->id, y->unit->id);
}
static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
[CGROUP_AUTO] = "auto",
[CGROUP_CLOSED] = "closed",
[CGROUP_STRICT] = "strict",
};
DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);