/
cgfsng.c
1985 lines (1695 loc) · 46.1 KB
/
cgfsng.c
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/*
* lxc: linux Container library
*
* Copyright © 2016 Canonical Ltd.
*
* Authors:
* Serge Hallyn <serge.hallyn@ubuntu.com>
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* cgfs-ng.c: this is a new, simplified implementation of a filesystem
* cgroup backend. The original cgfs.c was designed to be as flexible
* as possible. It would try to find cgroup filesystems no matter where
* or how you had them mounted, and deduce the most usable mount for
* each controller. It also was not designed for unprivileged use, as
* that was reserved for cgmanager.
*
* This new implementation assumes that cgroup filesystems are mounted
* under /sys/fs/cgroup/clist where clist is either the controller, or
* a comman-separated list of controllers.
*/
#include "config.h"
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <grp.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include "bdev.h"
#include "cgroup.h"
#include "cgroup_utils.h"
#include "commands.h"
#include "log.h"
#include "utils.h"
lxc_log_define(lxc_cgfsng, lxc);
static struct cgroup_ops cgfsng_ops;
/*
* A descriptor for a mounted hierarchy
* @controllers: either NULL, or a null-terminated list of all
* the co-mounted controllers
* @mountpoint: the mountpoint we will use. It will be either
* /sys/fs/cgroup/controller or /sys/fs/cgroup/controllerlist
* @base_cgroup: the cgroup under which the container cgroup path
is created. This will be either the caller's cgroup (if not
root), or init's cgroup (if root).
*/
struct hierarchy {
char **controllers;
char *mountpoint;
char *base_cgroup;
char *fullcgpath;
bool is_cgroup_v2;
};
/*
* The cgroup data which is attached to the lxc_handler.
* @cgroup_pattern - a copy of the lxc.cgroup.pattern
* @container_cgroup - if not null, the cgroup which was created for
* the container. For each hierarchy, it is created under the
* @hierarchy->base_cgroup directory. Relative to the base_cgroup
* it is the same for all hierarchies.
* @name - the container name
*/
struct cgfsng_handler_data {
char *cgroup_pattern;
char *container_cgroup; // cgroup we created for the container
char *name; // container name
};
/*
* @hierarchies - a NULL-terminated array of struct hierarchy, one per
* hierarchy. No duplicates. First sufficient, writeable mounted
* hierarchy wins
*/
struct hierarchy **hierarchies;
/*
* @cgroup_use - a copy of the lxc.cgroup.use
*/
char *cgroup_use;
/*
* @lxc_cgfsng_debug - whether to print debug info to stdout for the cgfsng
* driver
*/
static bool lxc_cgfsng_debug;
static void free_string_list(char **clist)
{
if (clist) {
int i;
for (i = 0; clist[i]; i++)
free(clist[i]);
free(clist);
}
}
/* Allocate a pointer, do not fail */
static void *must_alloc(size_t sz)
{
return must_realloc(NULL, sz);
}
/*
* This is a special case - return a copy of @entry
* prepending 'name='. I.e. turn systemd into name=systemd.
* Do not fail.
*/
static char *must_prefix_named(char *entry)
{
char *ret;
size_t len = strlen(entry);
ret = must_alloc(len + 6);
snprintf(ret, len + 6, "name=%s", entry);
return ret;
}
/*
* Given a pointer to a null-terminated array of pointers, realloc to
* add one entry, and point the new entry to NULL. Do not fail. Return
* the index to the second-to-last entry - that is, the one which is
* now available for use (keeping the list null-terminated).
*/
static int append_null_to_list(void ***list)
{
int newentry = 0;
if (*list)
for (; (*list)[newentry]; newentry++);
*list = must_realloc(*list, (newentry + 2) * sizeof(void **));
(*list)[newentry + 1] = NULL;
return newentry;
}
/*
* Given a null-terminated array of strings, check whether @entry
* is one of the strings
*/
static bool string_in_list(char **list, const char *entry)
{
int i;
if (!list)
return false;
for (i = 0; list[i]; i++)
if (strcmp(list[i], entry) == 0)
return true;
return false;
}
/*
* append an entry to the clist. Do not fail.
* *clist must be NULL the first time we are called.
*
* We also handle named subsystems here. Any controller which is not a
* kernel subsystem, we prefix 'name='. Any which is both a kernel and
* named subsystem, we refuse to use because we're not sure which we
* have here. (TODO - we could work around this in some cases by just
* remounting to be unambiguous, or by comparing mountpoint contents
* with current cgroup)
*
* The last entry will always be NULL.
*/
static void must_append_controller(char **klist, char **nlist, char ***clist, char *entry)
{
int newentry;
char *copy;
if (string_in_list(klist, entry) && string_in_list(nlist, entry)) {
ERROR("Refusing to use ambiguous controller '%s'", entry);
ERROR("It is both a named and kernel subsystem");
return;
}
newentry = append_null_to_list((void ***)clist);
if (strncmp(entry, "name=", 5) == 0)
copy = must_copy_string(entry);
else if (string_in_list(klist, entry))
copy = must_copy_string(entry);
else
copy = must_prefix_named(entry);
(*clist)[newentry] = copy;
}
static void free_handler_data(struct cgfsng_handler_data *d)
{
free(d->cgroup_pattern);
free(d->container_cgroup);
free(d->name);
free(d);
}
/*
* Given a handler's cgroup data, return the struct hierarchy for the
* controller @c, or NULL if there is none.
*/
struct hierarchy *get_hierarchy(const char *c)
{
int i;
if (!hierarchies)
return NULL;
for (i = 0; hierarchies[i]; i++) {
if (string_in_list(hierarchies[i]->controllers, c))
return hierarchies[i];
}
return NULL;
}
#define BATCH_SIZE 50
static void batch_realloc(char **mem, size_t oldlen, size_t newlen)
{
int newbatches = (newlen / BATCH_SIZE) + 1;
int oldbatches = (oldlen / BATCH_SIZE) + 1;
if (!*mem || newbatches > oldbatches) {
*mem = must_realloc(*mem, newbatches * BATCH_SIZE);
}
}
static void append_line(char **dest, size_t oldlen, char *new, size_t newlen)
{
size_t full = oldlen + newlen;
batch_realloc(dest, oldlen, full + 1);
memcpy(*dest + oldlen, new, newlen + 1);
}
/* Slurp in a whole file */
static char *read_file(char *fnam)
{
FILE *f;
char *line = NULL, *buf = NULL;
size_t len = 0, fulllen = 0;
int linelen;
f = fopen(fnam, "r");
if (!f)
return NULL;
while ((linelen = getline(&line, &len, f)) != -1) {
append_line(&buf, fulllen, line, linelen);
fulllen += linelen;
}
fclose(f);
free(line);
return buf;
}
/* Taken over modified from the kernel sources. */
#define NBITS 32 /* bits in uint32_t */
#define DIV_ROUND_UP(n, d) (((n) + (d)-1) / (d))
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, NBITS)
static void set_bit(unsigned bit, uint32_t *bitarr)
{
bitarr[bit / NBITS] |= (1 << (bit % NBITS));
}
static void clear_bit(unsigned bit, uint32_t *bitarr)
{
bitarr[bit / NBITS] &= ~(1 << (bit % NBITS));
}
static bool is_set(unsigned bit, uint32_t *bitarr)
{
return (bitarr[bit / NBITS] & (1 << (bit % NBITS))) != 0;
}
/* Create cpumask from cpulist aka turn:
*
* 0,2-3
*
* into bit array
*
* 1 0 1 1
*/
static uint32_t *lxc_cpumask(char *buf, size_t nbits)
{
char *token;
char *saveptr = NULL;
size_t arrlen = BITS_TO_LONGS(nbits);
uint32_t *bitarr = calloc(arrlen, sizeof(uint32_t));
if (!bitarr)
return NULL;
for (; (token = strtok_r(buf, ",", &saveptr)); buf = NULL) {
errno = 0;
unsigned start = strtoul(token, NULL, 0);
unsigned end = start;
char *range = strchr(token, '-');
if (range)
end = strtoul(range + 1, NULL, 0);
if (!(start <= end)) {
free(bitarr);
return NULL;
}
if (end >= nbits) {
free(bitarr);
return NULL;
}
while (start <= end)
set_bit(start++, bitarr);
}
return bitarr;
}
/* Turn cpumask into simple, comma-separated cpulist. */
static char *lxc_cpumask_to_cpulist(uint32_t *bitarr, size_t nbits)
{
size_t i;
int ret;
char numstr[LXC_NUMSTRLEN64] = {0};
char **cpulist = NULL;
for (i = 0; i <= nbits; i++) {
if (is_set(i, bitarr)) {
ret = snprintf(numstr, LXC_NUMSTRLEN64, "%zu", i);
if (ret < 0 || (size_t)ret >= LXC_NUMSTRLEN64) {
lxc_free_array((void **)cpulist, free);
return NULL;
}
if (lxc_append_string(&cpulist, numstr) < 0) {
lxc_free_array((void **)cpulist, free);
return NULL;
}
}
}
return lxc_string_join(",", (const char **)cpulist, false);
}
static ssize_t get_max_cpus(char *cpulist)
{
char *c1, *c2;
char *maxcpus = cpulist;
size_t cpus = 0;
c1 = strrchr(maxcpus, ',');
if (c1)
c1++;
c2 = strrchr(maxcpus, '-');
if (c2)
c2++;
if (!c1 && !c2)
c1 = maxcpus;
else if (c1 > c2)
c2 = c1;
else if (c1 < c2)
c1 = c2;
else if (!c1 && c2) // The reverse case is obvs. not needed.
c1 = c2;
/* If the above logic is correct, c1 should always hold a valid string
* here.
*/
errno = 0;
cpus = strtoul(c1, NULL, 0);
if (errno != 0)
return -1;
return cpus;
}
#define __ISOL_CPUS "/sys/devices/system/cpu/isolated"
static bool filter_and_set_cpus(char *path, bool am_initialized)
{
char *lastslash, *fpath, oldv;
int ret;
ssize_t i;
ssize_t maxposs = 0, maxisol = 0;
char *cpulist = NULL, *posscpus = NULL, *isolcpus = NULL;
uint32_t *possmask = NULL, *isolmask = NULL;
bool bret = false, flipped_bit = false;
lastslash = strrchr(path, '/');
if (!lastslash) { // bug... this shouldn't be possible
ERROR("Invalid path: %s.", path);
return bret;
}
oldv = *lastslash;
*lastslash = '\0';
fpath = must_make_path(path, "cpuset.cpus", NULL);
posscpus = read_file(fpath);
if (!posscpus) {
SYSERROR("Could not read file: %s.\n", fpath);
goto on_error;
}
/* Get maximum number of cpus found in possible cpuset. */
maxposs = get_max_cpus(posscpus);
if (maxposs < 0)
goto on_error;
if (!file_exists(__ISOL_CPUS)) {
/* This system doesn't expose isolated cpus. */
DEBUG("Path: "__ISOL_CPUS" to read isolated cpus from does not exist.\n");
cpulist = posscpus;
/* No isolated cpus but we weren't already initialized by
* someone. We should simply copy the parents cpuset.cpus
* values.
*/
if (!am_initialized) {
DEBUG("Copying cpuset of parent cgroup.");
goto copy_parent;
}
/* No isolated cpus but we were already initialized by someone.
* Nothing more to do for us.
*/
goto on_success;
}
isolcpus = read_file(__ISOL_CPUS);
if (!isolcpus) {
SYSERROR("Could not read file "__ISOL_CPUS);
goto on_error;
}
if (!isdigit(isolcpus[0])) {
DEBUG("No isolated cpus detected.");
cpulist = posscpus;
/* No isolated cpus but we weren't already initialized by
* someone. We should simply copy the parents cpuset.cpus
* values.
*/
if (!am_initialized) {
DEBUG("Copying cpuset of parent cgroup.");
goto copy_parent;
}
/* No isolated cpus but we were already initialized by someone.
* Nothing more to do for us.
*/
goto on_success;
}
/* Get maximum number of cpus found in isolated cpuset. */
maxisol = get_max_cpus(isolcpus);
if (maxisol < 0)
goto on_error;
if (maxposs < maxisol)
maxposs = maxisol;
maxposs++;
possmask = lxc_cpumask(posscpus, maxposs);
if (!possmask) {
ERROR("Could not create cpumask for all possible cpus.\n");
goto on_error;
}
isolmask = lxc_cpumask(isolcpus, maxposs);
if (!isolmask) {
ERROR("Could not create cpumask for all isolated cpus.\n");
goto on_error;
}
for (i = 0; i <= maxposs; i++) {
if (is_set(i, isolmask) && is_set(i, possmask)) {
flipped_bit = true;
clear_bit(i, possmask);
}
}
if (!flipped_bit) {
DEBUG("No isolated cpus present in cpuset.");
goto on_success;
}
DEBUG("Removed isolated cpus from cpuset.");
cpulist = lxc_cpumask_to_cpulist(possmask, maxposs);
if (!cpulist) {
ERROR("Could not create cpu list.\n");
goto on_error;
}
copy_parent:
*lastslash = oldv;
fpath = must_make_path(path, "cpuset.cpus", NULL);
ret = lxc_write_to_file(fpath, cpulist, strlen(cpulist), false);
if (ret < 0) {
SYSERROR("Could not write cpu list to: %s.\n", fpath);
goto on_error;
}
on_success:
bret = true;
on_error:
free(fpath);
free(isolcpus);
free(isolmask);
if (posscpus != cpulist)
free(posscpus);
free(possmask);
free(cpulist);
return bret;
}
/* Copy contents of parent(@path)/@file to @path/@file */
static bool copy_parent_file(char *path, char *file)
{
char *lastslash, *value = NULL, *fpath, oldv;
int len = 0;
int ret;
lastslash = strrchr(path, '/');
if (!lastslash) { // bug... this shouldn't be possible
ERROR("cgfsng:copy_parent_file: bad path %s", path);
return false;
}
oldv = *lastslash;
*lastslash = '\0';
fpath = must_make_path(path, file, NULL);
len = lxc_read_from_file(fpath, NULL, 0);
if (len <= 0)
goto bad;
value = must_alloc(len + 1);
if (lxc_read_from_file(fpath, value, len) != len)
goto bad;
free(fpath);
*lastslash = oldv;
fpath = must_make_path(path, file, NULL);
ret = lxc_write_to_file(fpath, value, len, false);
if (ret < 0)
SYSERROR("Unable to write %s to %s", value, fpath);
free(fpath);
free(value);
return ret >= 0;
bad:
SYSERROR("Error reading '%s'", fpath);
free(fpath);
free(value);
return false;
}
/*
* Initialize the cpuset hierarchy in first directory of @gname and
* set cgroup.clone_children so that children inherit settings.
* Since the h->base_path is populated by init or ourselves, we know
* it is already initialized.
*/
static bool handle_cpuset_hierarchy(struct hierarchy *h, char *cgname)
{
char *cgpath, *clonechildrenpath, v, *slash;
if (!string_in_list(h->controllers, "cpuset"))
return true;
if (*cgname == '/')
cgname++;
slash = strchr(cgname, '/');
if (slash)
*slash = '\0';
cgpath = must_make_path(h->mountpoint, h->base_cgroup, cgname, NULL);
if (slash)
*slash = '/';
if (mkdir(cgpath, 0755) < 0 && errno != EEXIST) {
SYSERROR("Failed to create '%s'", cgpath);
free(cgpath);
return false;
}
clonechildrenpath = must_make_path(cgpath, "cgroup.clone_children", NULL);
/* unified hierarchy doesn't have clone_children */
if (!file_exists(clonechildrenpath)) {
free(clonechildrenpath);
free(cgpath);
return true;
}
if (lxc_read_from_file(clonechildrenpath, &v, 1) < 0) {
SYSERROR("Failed to read '%s'", clonechildrenpath);
free(clonechildrenpath);
free(cgpath);
return false;
}
/* Make sure any isolated cpus are removed from cpuset.cpus. */
if (!filter_and_set_cpus(cgpath, v == '1')) {
SYSERROR("Failed to remove isolated cpus.");
free(clonechildrenpath);
free(cgpath);
return false;
}
if (v == '1') { /* already set for us by someone else */
DEBUG("\"cgroup.clone_children\" was already set to \"1\".");
free(clonechildrenpath);
free(cgpath);
return true;
}
/* copy parent's settings */
if (!copy_parent_file(cgpath, "cpuset.mems")) {
SYSERROR("Failed to copy \"cpuset.mems\" settings.");
free(cgpath);
free(clonechildrenpath);
return false;
}
free(cgpath);
if (lxc_write_to_file(clonechildrenpath, "1", 1, false) < 0) {
/* Set clone_children so children inherit our settings */
SYSERROR("Failed to write 1 to %s", clonechildrenpath);
free(clonechildrenpath);
return false;
}
free(clonechildrenpath);
return true;
}
/*
* Given two null-terminated lists of strings, return true if any string
* is in both.
*/
static bool controller_lists_intersect(char **l1, char **l2)
{
int i;
if (!l1 || !l2)
return false;
for (i = 0; l1[i]; i++) {
if (string_in_list(l2, l1[i]))
return true;
}
return false;
}
/*
* For a null-terminated list of controllers @clist, return true if any of
* those controllers is already listed the null-terminated list of
* hierarchies @hlist. Realistically, if one is present, all must be present.
*/
static bool controller_list_is_dup(struct hierarchy **hlist, char **clist)
{
int i;
if (!hlist)
return false;
for (i = 0; hlist[i]; i++)
if (controller_lists_intersect(hlist[i]->controllers, clist))
return true;
return false;
}
/*
* Return true if the controller @entry is found in the null-terminated
* list of hierarchies @hlist
*/
static bool controller_found(struct hierarchy **hlist, char *entry)
{
int i;
if (!hlist)
return false;
for (i = 0; hlist[i]; i++)
if (string_in_list(hlist[i]->controllers, entry))
return true;
return false;
}
/*
* Return true if all of the controllers which we require have been found.
* The required list is freezer and anything in * lxc.cgroup.use.
*/
static bool all_controllers_found(void)
{
char *p, *saveptr = NULL;
struct hierarchy ** hlist = hierarchies;
if (!controller_found(hlist, "freezer")) {
ERROR("no freezer controller mountpoint found");
return false;
}
if (!cgroup_use)
return true;
for (p = strtok_r(cgroup_use, ",", &saveptr); p;
p = strtok_r(NULL, ",", &saveptr)) {
if (!controller_found(hlist, p)) {
ERROR("no %s controller mountpoint found", p);
return false;
}
}
return true;
}
/* Return true if the fs type is fuse.lxcfs */
static bool is_lxcfs(const char *line)
{
char *p = strstr(line, " - ");
if (!p)
return false;
return strncmp(p, " - fuse.lxcfs ", 14) == 0;
}
/*
* Get the controllers from a mountinfo line
* There are other ways we could get this info. For lxcfs, field 3
* is /cgroup/controller-list. For cgroupfs, we could parse the mount
* options. But we simply assume that the mountpoint must be
* /sys/fs/cgroup/controller-list
*/
static char **get_controllers(char **klist, char **nlist, char *line)
{
/* the fourth field is /sys/fs/cgroup/comma-delimited-controller-list */
int i;
char *p = line, *p2, *tok, *saveptr = NULL;
char **aret = NULL;
bool is_cgroup_v2;
/* handle cgroup v2 */
is_cgroup_v2 = is_cgroupfs_v2(line);
for (i = 0; i < 4; i++) {
p = strchr(p, ' ');
if (!p)
return NULL;
p++;
}
if (!p)
return NULL;
/* note - if we change how mountinfo works, then our caller
* will need to verify /sys/fs/cgroup/ in this field */
if (strncmp(p, "/sys/fs/cgroup/", 15) != 0) {
INFO("cgfsng: found hierarchy not under /sys/fs/cgroup: \"%s\"", p);
return NULL;
}
p += 15;
p2 = strchr(p, ' ');
if (!p2) {
ERROR("corrupt mountinfo");
return NULL;
}
*p2 = '\0';
/* cgroup v2 does not have separate mountpoints for controllers */
if (is_cgroup_v2) {
must_append_controller(klist, nlist, &aret, "cgroup2");
return aret;
}
for (tok = strtok_r(p, ",", &saveptr); tok;
tok = strtok_r(NULL, ",", &saveptr)) {
must_append_controller(klist, nlist, &aret, tok);
}
return aret;
}
/* Add a controller to our list of hierarchies */
static void add_controller(char **clist, char *mountpoint, char *base_cgroup)
{
struct hierarchy *new;
int newentry;
new = must_alloc(sizeof(*new));
new->controllers = clist;
new->mountpoint = mountpoint;
new->base_cgroup = base_cgroup;
new->fullcgpath = NULL;
/* record if this is the cgroup v2 hierarchy */
if (!strcmp(base_cgroup, "cgroup2"))
new->is_cgroup_v2 = true;
else
new->is_cgroup_v2 = false;
newentry = append_null_to_list((void ***)&hierarchies);
hierarchies[newentry] = new;
}
/*
* Get a copy of the mountpoint from @line, which is a line from
* /proc/self/mountinfo
*/
static char *get_mountpoint(char *line)
{
int i;
char *p = line, *sret;
size_t len;
for (i = 0; i < 4; i++) {
p = strchr(p, ' ');
if (!p)
return NULL;
p++;
}
/* we've already stuck a \0 after the mountpoint */
len = strlen(p);
sret = must_alloc(len + 1);
memcpy(sret, p, len);
sret[len] = '\0';
return sret;
}
/*
* Given a multi-line string, return a null-terminated copy of the
* current line.
*/
static char *copy_to_eol(char *p)
{
char *p2 = strchr(p, '\n'), *sret;
size_t len;
if (!p2)
return NULL;
len = p2 - p;
sret = must_alloc(len + 1);
memcpy(sret, p, len);
sret[len] = '\0';
return sret;
}
/*
* cgline: pointer to character after the first ':' in a line in a
* \n-terminated /proc/self/cgroup file. Check whether * controller c is
* present.
*/
static bool controller_in_clist(char *cgline, char *c)
{
char *tok, *saveptr = NULL, *eol, *tmp;
size_t len;
eol = strchr(cgline, ':');
if (!eol)
return false;
len = eol - cgline;
tmp = alloca(len + 1);
memcpy(tmp, cgline, len);
tmp[len] = '\0';
for (tok = strtok_r(tmp, ",", &saveptr); tok;
tok = strtok_r(NULL, ",", &saveptr)) {
if (strcmp(tok, c) == 0)
return true;
}
return false;
}
/*
* @basecginfo is a copy of /proc/$$/cgroup. Return the current
* cgroup for @controller
*/
static char *get_current_cgroup(char *basecginfo, char *controller)
{
char *p = basecginfo;
bool is_cgroup_v2;
bool is_cgroup_v2_base_cgroup;
is_cgroup_v2 = !strcmp(controller, "cgroup2");
while (true) {
is_cgroup_v2_base_cgroup = false;
/* cgroup v2 entry in "/proc/<pid>/cgroup": "0::/some/path" */
if (is_cgroup_v2 && (*p == '0'))
is_cgroup_v2_base_cgroup = true;
p = strchr(p, ':');
if (!p)
return NULL;
p++;
if (is_cgroup_v2_base_cgroup || controller_in_clist(p, controller)) {
p = strchr(p, ':');
if (!p)
return NULL;
p++;
return copy_to_eol(p);
}
p = strchr(p, '\n');
if (!p)
return NULL;
p++;
}
}
static void must_append_string(char ***list, char *entry)
{
int newentry = append_null_to_list((void ***)list);
char *copy;
copy = must_copy_string(entry);
(*list)[newentry] = copy;
}
static void get_existing_subsystems(char ***klist, char ***nlist)
{
FILE *f;
char *line = NULL;
size_t len = 0;
if ((f = fopen("/proc/self/cgroup", "r")) == NULL)
return;
while (getline(&line, &len, f) != -1) {
char *p, *p2, *tok, *saveptr = NULL;
p = strchr(line, ':');
if (!p)
continue;
p++;
p2 = strchr(p, ':');
if (!p2)
continue;
*p2 = '\0';
/* If the kernel has cgroup v2 support, then /proc/self/cgroup
* contains an entry of the form:
*
* 0::/some/path
*
* In this case we use "cgroup2" as controller name.
*/
if ((p2 - p) == 0) {
must_append_string(klist, "cgroup2");
continue;
}
for (tok = strtok_r(p, ",", &saveptr); tok;
tok = strtok_r(NULL, ",", &saveptr)) {
if (strncmp(tok, "name=", 5) == 0)
must_append_string(nlist, tok);
else
must_append_string(klist, tok);
}
}
free(line);
fclose(f);
}
static void trim(char *s)
{
size_t len = strlen(s);
while ((len > 1) && (s[len - 1] == '\n'))
s[--len] = '\0';
}
static void lxc_cgfsng_print_handler_data(const struct cgfsng_handler_data *d)
{
printf("Cgroup information:\n");
printf(" container name: %s\n", d->name ? d->name : "(null)");
printf(" lxc.cgroup.use: %s\n", cgroup_use ? cgroup_use : "(null)");
printf(" lxc.cgroup.pattern: %s\n", d->cgroup_pattern ? d->cgroup_pattern : "(null)");
printf(" cgroup: %s\n", d->container_cgroup ? d->container_cgroup : "(null)");
}
static void lxc_cgfsng_print_hierarchies()
{
struct hierarchy **it;
int i;
if (!hierarchies) {
printf(" No hierarchies found.");
return;
}
printf(" Hierarchies:\n");
for (i = 0, it = hierarchies; it && *it; it++, i++) {