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Systemd/src/core/cgroup.c

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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <fcntl.h>
#include <fnmatch.h>
#include "alloc-util.h"
#include "blockdev-util.h"
#include "bpf-firewall.h"
#include "bus-error.h"
#include "cgroup-util.h"
#include "cgroup.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
#include "procfs-util.h"
#include "special.h"
#include "stdio-util.h"
#include "string-table.h"
#include "string-util.h"
#include "virt.h"
#define CGROUP_CPU_QUOTA_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC)
bool manager_owns_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 (detect_container() > 0)
return false;
return isempty(m->cgroup_root) || path_equal(m->cgroup_root, "/");
}
bool unit_has_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_root_cgroup(u->manager))
return false;
return unit_has_name(u, SPECIAL_ROOT_SLICE);
}
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, assuming the
* structure is preinitialized to 0 */
c->cpu_weight = CGROUP_WEIGHT_INVALID;
c->startup_cpu_weight = CGROUP_WEIGHT_INVALID;
c->cpu_quota_per_sec_usec = USEC_INFINITY;
c->cpu_shares = CGROUP_CPU_SHARES_INVALID;
c->startup_cpu_shares = CGROUP_CPU_SHARES_INVALID;
c->memory_high = CGROUP_LIMIT_MAX;
c->memory_max = CGROUP_LIMIT_MAX;
c->memory_swap_max = CGROUP_LIMIT_MAX;
c->memory_limit = CGROUP_LIMIT_MAX;
c->io_weight = CGROUP_WEIGHT_INVALID;
c->startup_io_weight = CGROUP_WEIGHT_INVALID;
c->blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID;
c->startup_blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID;
c->tasks_max = (uint64_t) -1;
}
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_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_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);
}
void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
CGroupIODeviceLimit *il;
CGroupIODeviceWeight *iw;
CGroupBlockIODeviceBandwidth *b;
CGroupBlockIODeviceWeight *w;
CGroupDeviceAllow *a;
IPAddressAccessItem *iaai;
char u[FORMAT_TIMESPAN_MAX];
assert(c);
assert(f);
prefix = strempty(prefix);
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"
"%sIOWeight=%" PRIu64 "\n"
"%sStartupIOWeight=%" PRIu64 "\n"
"%sBlockIOWeight=%" PRIu64 "\n"
"%sStartupBlockIOWeight=%" PRIu64 "\n"
"%sMemoryLow=%" PRIu64 "\n"
"%sMemoryHigh=%" PRIu64 "\n"
"%sMemoryMax=%" PRIu64 "\n"
"%sMemorySwapMax=%" PRIu64 "\n"
"%sMemoryLimit=%" PRIu64 "\n"
"%sTasksMax=%" PRIu64 "\n"
"%sDevicePolicy=%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, c->io_weight,
prefix, c->startup_io_weight,
prefix, c->blockio_weight,
prefix, c->startup_blockio_weight,
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, 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,
prefix,
iw->path,
iw->weight);
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);
}
}
static int lookup_block_device(const char *p, dev_t *dev) {
struct stat st;
int r;
assert(p);
assert(dev);
r = stat(p, &st);
if (r < 0)
return log_warning_errno(errno, "Couldn't stat device %s: %m", p);
if (S_ISBLK(st.st_mode))
*dev = st.st_rdev;
else if (major(st.st_dev) != 0) {
/* If this is not a device node then find the block
* device this file is stored on */
*dev = st.st_dev;
/* If this is a partition, try to get the originating
* block device */
(void) block_get_whole_disk(*dev, dev);
} else {
log_warning("%s is not a block device and file system block device cannot be determined or is not local.", p);
return -ENODEV;
}
return 0;
}
static int whitelist_device(const char *path, const char *node, const char *acc) {
char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4];
struct stat st;
bool ignore_notfound;
int r;
assert(path);
assert(acc);
if (node[0] == '-') {
/* Non-existent paths starting with "-" must be silently ignored */
node++;
ignore_notfound = true;
} else
ignore_notfound = false;
if (stat(node, &st) < 0) {
if (errno == ENOENT && ignore_notfound)
return 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;
}
sprintf(buf,
"%c %u:%u %s",
S_ISCHR(st.st_mode) ? 'c' : 'b',
major(st.st_rdev), minor(st.st_rdev),
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 r;
}
static int whitelist_major(const char *path, const char *name, char type, const char *acc) {
_cleanup_fclose_ FILE *f = NULL;
char line[LINE_MAX];
bool good = false;
int r;
assert(path);
assert(acc);
assert(IN_SET(type, 'b', 'c'));
f = fopen("/proc/devices", "re");
if (!f)
return log_warning_errno(errno, "Cannot open /proc/devices to resolve %s (%c): %m", name, type);
FOREACH_LINE(line, f, goto fail) {
char buf[2+DECIMAL_STR_MAX(unsigned)+3+4], *p, *w;
unsigned maj;
truncate_nl(line);
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;
sprintf(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;
fail:
return log_warning_errno(errno, "Failed to read /proc/devices: %m");
}
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;
}
static void cgroup_apply_unified_cpu_config(Unit *u, uint64_t weight, uint64_t quota) {
char buf[MAX(DECIMAL_STR_MAX(uint64_t) + 1, (DECIMAL_STR_MAX(usec_t) + 1) * 2)];
int r;
xsprintf(buf, "%" PRIu64 "\n", weight);
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.weight", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set cpu.weight: %m");
if (quota != USEC_INFINITY)
xsprintf(buf, USEC_FMT " " USEC_FMT "\n",
quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC, CGROUP_CPU_QUOTA_PERIOD_USEC);
else
xsprintf(buf, "max " USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC);
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.max", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set cpu.max: %m");
}
static void cgroup_apply_legacy_cpu_config(Unit *u, uint64_t shares, uint64_t quota) {
char buf[MAX(DECIMAL_STR_MAX(uint64_t), DECIMAL_STR_MAX(usec_t)) + 1];
int r;
xsprintf(buf, "%" PRIu64 "\n", shares);
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.shares", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set cpu.shares: %m");
xsprintf(buf, USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC);
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.cfs_period_us", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set cpu.cfs_period_us: %m");
if (quota != USEC_INFINITY) {
xsprintf(buf, USEC_FMT "\n", quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC);
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.cfs_quota_us", buf);
} else
r = cg_set_attribute("cpu", u->cgroup_path, "cpu.cfs_quota_us", "-1");
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set cpu.cfs_quota_us: %m");
}
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_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);
r = cg_set_attribute("io", u->cgroup_path, "io.weight", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set io.weight: %m");
}
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);
r = cg_set_attribute("blkio", u->cgroup_path, "blkio.weight_device", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set blkio.weight_device: %m");
}
static unsigned 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;
unsigned n = 0;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return 0;
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]);
n++;
} 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]);
r = cg_set_attribute("io", u->cgroup_path, "io.max", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set io.max: %m");
return n;
}
static unsigned 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;
unsigned n = 0;
int r;
r = lookup_block_device(dev_path, &dev);
if (r < 0)
return 0;
if (rbps != CGROUP_LIMIT_MAX)
n++;
sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), rbps);
r = cg_set_attribute("blkio", u->cgroup_path, "blkio.throttle.read_bps_device", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set blkio.throttle.read_bps_device: %m");
if (wbps != CGROUP_LIMIT_MAX)
n++;
sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), wbps);
r = cg_set_attribute("blkio", u->cgroup_path, "blkio.throttle.write_bps_device", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set blkio.throttle.write_bps_device: %m");
return n;
}
static bool cgroup_context_has_unified_memory_config(CGroupContext *c) {
return c->memory_low > 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";
int r;
if (v != CGROUP_LIMIT_MAX)
xsprintf(buf, "%" PRIu64 "\n", v);
r = cg_set_attribute("memory", u->cgroup_path, file, buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set %s: %m", file);
}
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_install(u);
}
static void cgroup_context_apply(
Unit *u,
CGroupMask apply_mask,
bool apply_bpf,
ManagerState state) {
const char *path;
CGroupContext *c;
bool is_root;
int r;
assert(u);
/* Nothing to do? Exit early! */
if (apply_mask == 0 && !apply_bpf)
return;
/* Some cgroup attributes are not supported on the root cgroup, hence silently ignore */
is_root = unit_has_root_cgroup(u);
assert_se(c = unit_get_cgroup_context(u));
assert_se(path = u->cgroup_path);
if (is_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. */
if ((apply_mask & CGROUP_MASK_CPU) && !is_root) {
bool has_weight, has_shares;
has_weight = cgroup_context_has_cpu_weight(c);
has_shares = cgroup_context_has_cpu_shares(c);
if (cg_all_unified() > 0) {
uint64_t weight;
if (has_weight)
weight = cgroup_context_cpu_weight(c, state);
else if (has_shares) {
uint64_t 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_config(u, weight, c->cpu_quota_per_sec_usec);
} else {
uint64_t shares;
if (has_weight) {
uint64_t 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 (has_shares)
shares = cgroup_context_cpu_shares(c, state);
else
shares = CGROUP_CPU_SHARES_DEFAULT;
cgroup_apply_legacy_cpu_config(u, shares, c->cpu_quota_per_sec_usec);
}
}
if (apply_mask & CGROUP_MASK_IO) {
bool has_io = cgroup_context_has_io_config(c);
bool has_blockio = cgroup_context_has_blockio_config(c);
if (!is_root) {
char buf[8+DECIMAL_STR_MAX(uint64_t)+1];
uint64_t weight;
if (has_io)
weight = cgroup_context_io_weight(c, state);
else if (has_blockio) {
uint64_t 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);
r = cg_set_attribute("io", path, "io.weight", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set io.weight: %m");
if (has_io) {
CGroupIODeviceWeight *w;
/* FIXME: no way to reset this list */
LIST_FOREACH(device_weights, w, c->io_device_weights)
cgroup_apply_io_device_weight(u, w->path, w->weight);
} else if (has_blockio) {
CGroupBlockIODeviceWeight *w;
/* FIXME: no way to reset this list */
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);
}
}
}
/* Apply limits and free ones without config. */
if (has_io) {
CGroupIODeviceLimit *l, *next;
LIST_FOREACH_SAFE(device_limits, l, next, c->io_device_limits) {
if (!cgroup_apply_io_device_limit(u, l->path, l->limits))
cgroup_context_free_io_device_limit(c, l);
}
} else if (has_blockio) {
CGroupBlockIODeviceBandwidth *b, *next;
LIST_FOREACH_SAFE(device_bandwidths, b, next, 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);
if (!cgroup_apply_io_device_limit(u, b->path, limits))
cgroup_context_free_blockio_device_bandwidth(c, b);
}
}
}
if (apply_mask & CGROUP_MASK_BLKIO) {
bool has_io = cgroup_context_has_io_config(c);
bool has_blockio = cgroup_context_has_blockio_config(c);
if (!is_root) {
char buf[DECIMAL_STR_MAX(uint64_t)+1];
uint64_t weight;
if (has_io) {
uint64_t 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);
r = cg_set_attribute("blkio", path, "blkio.weight", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set blkio.weight: %m");
if (has_io) {
CGroupIODeviceWeight *w;
/* FIXME: no way to reset this list */
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;
/* FIXME: no way to reset this list */
LIST_FOREACH(device_weights, w, c->blockio_device_weights)
cgroup_apply_blkio_device_weight(u, w->path, w->weight);
}
}
/* Apply limits and free ones without config. */
if (has_io) {
CGroupIODeviceLimit *l, *next;
LIST_FOREACH_SAFE(device_limits, l, next, 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);
if (!cgroup_apply_blkio_device_limit(u, l->path, l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX]))
cgroup_context_free_io_device_limit(c, l);
}
} else if (has_blockio) {
CGroupBlockIODeviceBandwidth *b, *next;
LIST_FOREACH_SAFE(device_bandwidths, b, next, c->blockio_device_bandwidths)
if (!cgroup_apply_blkio_device_limit(u, b->path, b->rbps, b->wbps))
cgroup_context_free_blockio_device_bandwidth(c, b);
}
}
if ((apply_mask & CGROUP_MASK_MEMORY) && !is_root) {
if (cg_all_unified() > 0) {
uint64_t max, swap_max = CGROUP_LIMIT_MAX;
if (cgroup_context_has_unified_memory_config(c)) {
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.low", c->memory_low);
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);
} else {
char buf[DECIMAL_STR_MAX(uint64_t) + 1];
uint64_t val;
if (cgroup_context_has_unified_memory_config(c)) {
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);
r = cg_set_attribute("memory", path, "memory.limit_in_bytes", buf);
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set memory.limit_in_bytes: %m");
}
}
if ((apply_mask & CGROUP_MASK_DEVICES) && !is_root) {
CGroupDeviceAllow *a;
/* 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) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to reset devices.list: %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)
whitelist_device(path, x, y);
/* PTS (/dev/pts) devices may not be duplicated, but accessed */
whitelist_major(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/"))
whitelist_device(path, a->path, acc);
else if ((val = startswith(a->path, "block-")))
whitelist_major(path, val, 'b', acc);
else if ((val = startswith(a->path, "char-")))
whitelist_major(path, val, 'c', acc);
else
log_unit_debug(u, "Ignoring device %s while writing cgroup attribute.", a->path);
}
}
if (apply_mask & CGROUP_MASK_PIDS) {
if (is_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 offical 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, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to write to tasks limit sysctls: %m");
} else {
if (c->tasks_max != CGROUP_LIMIT_MAX) {
char buf[DECIMAL_STR_MAX(uint64_t) + 2];
sprintf(buf, "%" PRIu64 "\n", c->tasks_max);
r = cg_set_attribute("pids", path, "pids.max", buf);
} else
r = cg_set_attribute("pids", path, "pids.max", "max");
if (r < 0)
log_unit_full(u, IN_SET(r, -ENOENT, -EROFS, -EACCES) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to set pids.max: %m");
}
}
if (apply_bpf)
cgroup_apply_firewall(u);
}
CGroupMask cgroup_context_get_mask(CGroupContext *c) {
CGroupMask mask = 0;
/* Figure out which controllers we need */
if (c->cpu_accounting ||
cgroup_context_has_cpu_weight(c) ||
cgroup_context_has_cpu_shares(c) ||
c->cpu_quota_per_sec_usec != USEC_INFINITY)
mask |= CGROUP_MASK_CPUACCT | 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 ||
cgroup_context_has_unified_memory_config(c))
mask |= CGROUP_MASK_MEMORY;
if (c->device_allow ||
c->device_policy != CGROUP_AUTO)
mask |= CGROUP_MASK_DEVICES;
if (c->tasks_accounting ||
c->tasks_max != CGROUP_LIMIT_MAX)
mask |= CGROUP_MASK_PIDS;
return mask;
}
CGroupMask unit_get_own_mask(Unit *u) {
CGroupContext *c;
/* Returns the mask of controllers the unit needs for itself */
c = unit_get_cgroup_context(u);
if (!c)
return 0;
return cgroup_context_get_mask(c) | unit_get_delegate_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 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;
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 (member == u)
continue;
if (UNIT_DEREF(member->slice) != u)
continue;
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_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);
mask &= u->manager->cgroup_supported;
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;
return mask;
}
bool unit_get_needs_bpf(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)
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;
}
/* Recurse from a unit up through its containing slices, propagating
* mask bits upward. A unit is also member of itself. */
void unit_update_cgroup_members_masks(Unit *u) {
CGroupMask m;
bool more;
assert(u);
/* Calculate subtree mask */
m = unit_get_subtree_mask(u);
/* See if anything changed from the previous invocation. If
* not, we're done. */
if (u->cgroup_subtree_mask_valid && m == u->cgroup_subtree_mask)
return;
more =
u->cgroup_subtree_mask_valid &&
((m & ~u->cgroup_subtree_mask) != 0) &&
((~m & u->cgroup_subtree_mask) == 0);
u->cgroup_subtree_mask = m;
u->cgroup_subtree_mask_valid = true;
if (UNIT_ISSET(u->slice)) {
Unit *s = UNIT_DEREF(u->slice);
if (more)
/* There's more set now than before. We
* propagate the new mask to the parent's mask
* (not caring if it actually was valid or
* not). */
s->cgroup_members_mask |= m;
else
/* There's less set now than before (or we
* don't know), we need to recalculate
* everything, so let's invalidate the
* parent's members mask */
s->cgroup_members_mask_valid = false;
/* And now make sure that this change also hits our
* grandparents */
unit_update_cgroup_members_masks(s);
}
}
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 &&
(u->cgroup_realized_mask & 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(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;
if (slice)
return strjoin(u->manager->cgroup_root, "/", slice, "/",
escaped);
else
return strjoin(u->manager->cgroup_root, "/", escaped);
}
int unit_set_cgroup_path(Unit *u, const char *path) {
_cleanup_free_ char *p = NULL;
int r;
assert(u);
if (path) {
p = strdup(path);
if (!p)
return -ENOMEM;
} else
p = NULL;
if (streq_ptr(u->cgroup_path, p))
return 0;
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);
if (!u->cgroup_path)
return 0;
if (u->cgroup_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;
/* Don't watch the root slice, it's pointless. */
if (unit_has_name(u, SPECIAL_ROOT_SLICE))
return 0;
r = hashmap_ensure_allocated(&u->manager->cgroup_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_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY);
if (u->cgroup_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 inotify watch descriptor for control group %s: %m", u->cgroup_path);
}
r = hashmap_put(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd), u);
if (r < 0)
return log_unit_error_errno(u, r, "Failed to add 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,
bool needs_bpf) {
CGroupContext *c;
int r;
assert(u);
c = unit_get_cgroup_context(u);
if (!c)
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);
/* Start watching it */
(void) unit_watch_cgroup(u);
/* Enable all controllers we need */
r = cg_enable_everywhere(u->manager->cgroup_supported, enable_mask, u->cgroup_path);
if (r < 0)
log_unit_warning_errno(u, r, "Failed to enable controllers on cgroup %s, ignoring: %m", u->cgroup_path);
/* Keep track that this is now realized */
u->cgroup_realized = true;
u->cgroup_realized_mask = target_mask;
u->cgroup_enabled_mask = enable_mask;
u->cgroup_bpf_state = needs_bpf ? UNIT_CGROUP_BPF_ON : UNIT_CGROUP_BPF_OFF;
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);
}
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_kill_slashes(pp);
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;
r = unit_realize_cgroup(u);
if (r < 0)
return r;
if (isempty(suffix_path))
p = u->cgroup_path;
else
p = strjoina(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 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 bool unit_has_mask_realized(
Unit *u,
CGroupMask target_mask,
CGroupMask enable_mask,
bool needs_bpf) {
assert(u);
return u->cgroup_realized &&
u->cgroup_realized_mask == target_mask &&
u->cgroup_enabled_mask == enable_mask &&
((needs_bpf && u->cgroup_bpf_state == UNIT_CGROUP_BPF_ON) ||
(!needs_bpf && u->cgroup_bpf_state == UNIT_CGROUP_BPF_OFF));
}
static 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;
}
/* 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.
*
* Returns 0 on success and < 0 on failure. */
static int unit_realize_cgroup_now(Unit *u, ManagerState state) {
CGroupMask target_mask, enable_mask;
bool needs_bpf, apply_bpf;
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);
needs_bpf = unit_get_needs_bpf(u);
if (unit_has_mask_realized(u, target_mask, enable_mask, needs_bpf))
return 0;
/* Make sure we apply the BPF filters either when one is configured, or if none is configured but previously
* the state was anything but off. This way, if a unit with a BPF filter applied is reconfigured to lose it
* this will trickle down properly to cgroupfs. */
apply_bpf = needs_bpf || u->cgroup_bpf_state != UNIT_CGROUP_BPF_OFF;
/* First, realize parents */
if (UNIT_ISSET(u->slice)) {
r = unit_realize_cgroup_now(UNIT_DEREF(u->slice), state);
if (r < 0)
return r;
}
/* And then do the real work */
r = unit_create_cgroup(u, target_mask, enable_mask, needs_bpf);
if (r < 0)
return r;
/* Finally, apply the necessary attributes. */
cgroup_context_apply(u, target_mask, apply_bpf, state);
cgroup_xattr_apply(u);
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) {
if (m == u)
continue;
/* 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),
unit_get_needs_bpf(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 */
if (u->cgroup_path) {
(void) hashmap_remove(u->manager->cgroup_unit, u->cgroup_path);
u->cgroup_path = mfree(u->cgroup_path);
}
if (u->cgroup_inotify_wd >= 0) {
if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_inotify_wd) < 0)
log_unit_debug_errno(u, errno, "Failed to remove cgroup inotify watch %i for %s, ignoring", u->cgroup_inotify_wd, u->id);
(void) hashmap_remove(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd));
u->cgroup_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) {
log_unit_debug_errno(u, r, "Failed to destroy cgroup %s, ignoring: %m", u->cgroup_path);
return;
}
if (is_root_slice)
return;
unit_release_cgroup(u);
u->cgroup_realized = false;
u->cgroup_realized_mask = 0;
u->cgroup_enabled_mask = 0;
}
int unit_search_main_pid(Unit *u, pid_t *ret) {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0, npid, mypid;
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;
mypid = getpid_cached();
while (cg_read_pid(f, &npid) > 0) {
pid_t ppid;
if (npid == pid)
continue;
/* Ignore processes that aren't our kids */
if (get_process_ppid(npid, &ppid) >= 0 && ppid != mypid)
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);
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 = strjoin(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: %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");
}
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;
u = hashmap_get(m->cgroup_inotify_wd_unit, INT_TO_PTR(e->wd));
if (!u) /* Not 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. */
continue;
unit_add_to_cgroup_empty_queue(u);
}
}
}
int manager_setup_cgroup(Manager *m) {
_cleanup_free_ char *path = NULL;
const char *scope_path;
CGroupController c;
int r, all_unified;
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");
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, but after service notifications and SIGCHLD. 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-4);
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) && m->test_run_flags == 0) {
/* 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 (r < 0 && !m->test_run_flags)
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 && m->test_run_flags == 0)
(void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1");
/* 8. Figure out which controllers are supported, and log about it */
r = cg_mask_supported(&m->cgroup_supported);
if (r < 0)
return log_error_errno(r, "Failed to determine supported controllers: %m");
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)
(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_inotify_wd_unit = hashmap_free(m->cgroup_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_root_cgroup(u))
return procfs_memory_get_current(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_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_root_cgroup(u))
return procfs_cpu_get_usage(ret);
r = cg_all_unified();
if (r < 0)
return r;
if (r > 0) {
_cleanup_free_ char *val = NULL;
uint64_t us;
if ((u->cgroup_realized_mask & CGROUP_MASK_CPU) == 0)
return -ENODATA;
r = cg_get_keyed_attribute("cpu", u->cgroup_path, "cpu.stat", STRV_MAKE("usage_usec"), &val);
if (r < 0)
return r;
if (IN_SET(r, -ENOENT, -ENXIO))
return -ENODATA;
r = safe_atou64(val, &us);
if (r < 0)
return r;
ns = us * NSEC_PER_USEC;
} else {
if ((u->cgroup_realized_mask & CGROUP_MASK_CPUACCT) == 0)
return -ENODATA;
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;
}
int unit_reset_cpu_accounting(Unit *u) {
nsec_t ns;
int r;
assert(u);
u->cpu_usage_last = NSEC_INFINITY;
r = unit_get_cpu_usage_raw(u, &ns);
if (r < 0) {
u->cpu_usage_base = 0;
return r;
}
u->cpu_usage_base = ns;
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;
}
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 ((u->cgroup_realized_mask & m) == 0) /* NOP? */
return;
u->cgroup_realized_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_bpf_state == UNIT_CGROUP_BPF_INVALIDATED) /* NOP? */
return;
u->cgroup_bpf_state = UNIT_CGROUP_BPF_INVALIDATED;
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 (member == u)
continue;
if (UNIT_DEREF(member->slice) != u)
continue;
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 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);
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