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Unverified Commit 2202afc9 by Christian Brauner
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cgroups: refactor cgroup handling

This replaces the constructor implementation of cgroup handling with a simpler, thread-safe on-demand model of cgroup driver initialization. Making the cgroup initialization code run in a constructor means that each time the shared library gets mapped the cgroup parsing code gets run. That's unnecessary overhead. It also feels to me that this is only accidently thread-safe because constructors are only run once. But should threads actually end up manipulating or freeing memory that is file-global to cgfsng.c we'd be screwed. Now, I might be wrong here but the cleaner implementation is to allocate a cgroup driver on demand whenever we need it. Take the chance and rework the cgroup_ops interface to make the functions it wants to have implemented a lot cleaner. Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
parent b5ead53a
Showing with 762 additions and 986 deletions
src/lxc/attach.c
......@@ -1272,10 +1272,17 @@ int lxc_attach(const char *name, const char *lxcpath,
/* Attach to cgroup, if requested. */
if (options->attach_flags & LXC_ATTACH_MOVE_TO_CGROUP) {
if (!cgroup_attach(name, lxcpath, pid))
struct cgroup_ops *cgroup_ops;
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
goto on_error;
if (!cgroup_ops->attach(cgroup_ops, name, lxcpath, pid))
goto on_error;
TRACE("Moved intermediate process %d into container's "
"cgroups", pid);
cgroup_exit(cgroup_ops);
TRACE("Moved intermediate process %d into container's cgroups", pid);
}
/* Setup /proc limits */
......
src/lxc/cgroups/cgfsng.c
......@@ -60,138 +60,6 @@
lxc_log_define(lxc_cgfsng, lxc);
static struct cgroup_ops cgfsng_ops;
/* A descriptor for a mounted hierarchy
*
* @controllers
* - legacy hierarchy
* Either NULL, or a null-terminated list of all the co-mounted controllers.
* - unified hierarchy
* Either NULL, or a null-terminated list of all enabled controllers.
*
* @mountpoint
* - The mountpoint we will use.
* - legacy hierarchy
* It will be either /sys/fs/cgroup/controller or
* /sys/fs/cgroup/controllerlist.
* - unified hierarchy
* It will either be /sys/fs/cgroup or /sys/fs/cgroup/<mountpoint-name>
* depending on whether this is a hybrid cgroup layout (mix of legacy and
* unified hierarchies) or a pure unified cgroup layout.
*
* @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).
*
* @fullcgpath
* - The full path to the containers cgroup.
*
* @version
* - legacy hierarchy
* If the hierarchy is a legacy hierarchy this will be set to
* CGROUP_SUPER_MAGIC.
* - unified hierarchy
* If the hierarchy is a legacy hierarchy this will be set to
* CGROUP2_SUPER_MAGIC.
*/
struct hierarchy {
char **controllers;
char *mountpoint;
char *base_cgroup;
char *fullcgpath;
int version;
};
/* The cgroup data which is attached to the lxc_handler.
*
* @cgroup_pattern
* - A copy of 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 name of the container.
*
* @cgroup_meta
* - A copy of the container's cgroup information. This overrides
* @cgroup_pattern.
*
* @cgroup_layout
* - What cgroup layout the container is running with.
* - CGROUP_LAYOUT_UNKNOWN
* The cgroup layout could not be determined. This should be treated as an
* error condition.
* - CGROUP_LAYOUT_LEGACY
* The container is running with all controllers mounted into legacy cgroup
* hierarchies.
* - CGROUP_LAYOUT_HYBRID
* The container is running with at least one controller mounted into a
* legacy cgroup hierarchy and a mountpoint for the unified hierarchy. The
* unified hierarchy can be empty (no controllers enabled) or non-empty
* (controllers enabled).
* - CGROUP_LAYOUT_UNIFIED
* The container is running on a pure unified cgroup hierarchy. The unified
* hierarchy can be empty (no controllers enabled) or non-empty (controllers
* enabled).
*/
struct cgfsng_handler_data {
char *cgroup_pattern;
char *container_cgroup; /* cgroup we created for the container */
char *name; /* container name */
/* per-container cgroup information */
struct lxc_cgroup cgroup_meta;
cgroup_layout_t cgroup_layout;
};
/* @hierarchies
* - A NULL-terminated array of struct hierarchy, one per legacy hierarchy. No
* duplicates. First sufficient, writeable mounted hierarchy wins.
*/
struct hierarchy **hierarchies;
/* Pointer to the unified hierarchy in the null terminated list @hierarchies.
* This is merely a convenience for hybrid cgroup layouts to easily retrieve the
* unified hierarchy without iterating throught @hierarchies.
*/
struct hierarchy *unified;
/*
* @cgroup_layout
* - What cgroup layout the container is running with.
* - CGROUP_LAYOUT_UNKNOWN
* The cgroup layout could not be determined. This should be treated as an
* error condition.
* - CGROUP_LAYOUT_LEGACY
* The container is running with all controllers mounted into legacy cgroup
* hierarchies.
* - CGROUP_LAYOUT_HYBRID
* The container is running with at least one controller mounted into a
* legacy cgroup hierarchy and a mountpoint for the unified hierarchy. The
* unified hierarchy can be empty (no controllers enabled) or non-empty
* (controllers enabled).
* - CGROUP_LAYOUT_UNIFIED
* The container is running on a pure unified cgroup hierarchy. The unified
* hierarchy can be empty (no controllers enabled) or non-empty (controllers
* enabled).
*/
cgroup_layout_t cgroup_layout;
/* What controllers is the container supposed to use. */
char *cgroup_use;
/* @lxc_cgfsng_debug
* - Whether to print debug info to stdout for the cgfsng driver.
*/
static bool lxc_cgfsng_debug;
#define CGFSNG_DEBUG(format, ...) \
do { \
if (lxc_cgfsng_debug) \
printf("cgfsng: " format, ##__VA_ARGS__); \
} while (0)
static void free_string_list(char **clist)
{
int i;
......@@ -298,40 +166,28 @@ static void must_append_controller(char **klist, char **nlist, char ***clist,
(*clist)[newentry] = copy;
}
static void free_handler_data(struct cgfsng_handler_data *d)
{
free(d->cgroup_pattern);
free(d->container_cgroup);
free(d->name);
if (d->cgroup_meta.dir)
free(d->cgroup_meta.dir);
if (d->cgroup_meta.controllers)
free(d->cgroup_meta.controllers);
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)
struct hierarchy *get_hierarchy(struct cgroup_ops *ops, const char *c)
{
int i;
if (!hierarchies)
if (!ops->hierarchies)
return NULL;
for (i = 0; hierarchies[i]; i++) {
for (i = 0; ops->hierarchies[i]; i++) {
if (!c) {
/* This is the empty unified hierarchy. */
if (hierarchies[i]->controllers &&
!hierarchies[i]->controllers[0])
return hierarchies[i];
if (ops->hierarchies[i]->controllers &&
!ops->hierarchies[i]->controllers[0])
return ops->hierarchies[i];
continue;
}
if (string_in_list(hierarchies[i]->controllers, c))
return hierarchies[i];
if (string_in_list(ops->hierarchies[i]->controllers, c))
return ops->hierarchies[i];
}
return NULL;
......@@ -829,23 +685,23 @@ static bool controller_found(struct hierarchy **hlist, char *entry)
/* 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)
static bool all_controllers_found(struct cgroup_ops *ops)
{
char *p;
char *saveptr = NULL;
struct hierarchy **hlist = hierarchies;
struct hierarchy **hlist = ops->hierarchies;
if (!controller_found(hlist, "freezer")) {
CGFSNG_DEBUG("No freezer controller mountpoint found\n");
ERROR("No freezer controller mountpoint found");
return false;
}
if (!cgroup_use)
if (!ops->cgroup_use)
return true;
for (; (p = strtok_r(cgroup_use, ",", &saveptr)); cgroup_use = NULL)
for (; (p = strtok_r(ops->cgroup_use, ",", &saveptr)); ops->cgroup_use = NULL)
if (!controller_found(hlist, p)) {
CGFSNG_DEBUG("No %s controller mountpoint found\n", p);
ERROR("No %s controller mountpoint found", p);
return false;
}
......@@ -879,14 +735,14 @@ static char **cg_hybrid_get_controllers(char **klist, char **nlist, char *line,
* verify /sys/fs/cgroup/ in this field.
*/
if (strncmp(p, "/sys/fs/cgroup/", 15) != 0) {
CGFSNG_DEBUG("Found hierarchy not under /sys/fs/cgroup: \"%s\"\n", p);
ERROR("Found hierarchy not under /sys/fs/cgroup: \"%s\"", p);
return NULL;
}
p += 15;
p2 = strchr(p, ' ');
if (!p2) {
CGFSNG_DEBUG("Corrupt mountinfo\n");
ERROR("Corrupt mountinfo");
return NULL;
}
*p2 = '\0';
......@@ -944,7 +800,7 @@ static char **cg_unified_get_controllers(const char *file)
return aret;
}
static struct hierarchy *add_hierarchy(char **clist, char *mountpoint,
static struct hierarchy *add_hierarchy(struct hierarchy ***h, char **clist, char *mountpoint,
char *base_cgroup, int type)
{
struct hierarchy *new;
......@@ -957,8 +813,8 @@ static struct hierarchy *add_hierarchy(char **clist, char *mountpoint,
new->fullcgpath = NULL;
new->version = type;
newentry = append_null_to_list((void ***)&hierarchies);
hierarchies[newentry] = new;
newentry = append_null_to_list((void ***)h);
(*h)[newentry] = new;
return new;
}
......@@ -1137,39 +993,26 @@ static void trim(char *s)
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(" lxc.cgroup.dir: %s\n",
d->cgroup_meta.dir ? d->cgroup_meta.dir : "(null)");
printf(" cgroup: %s\n",
d->container_cgroup ? d->container_cgroup : "(null)");
}
static void lxc_cgfsng_print_hierarchies()
static void lxc_cgfsng_print_hierarchies(struct cgroup_ops *ops)
{
int i;
struct hierarchy **it;
if (!hierarchies) {
printf(" No hierarchies found\n");
if (!ops->hierarchies) {
TRACE(" No hierarchies found");
return;
}
printf(" Hierarchies:\n");
for (i = 0, it = hierarchies; it && *it; it++, i++) {
TRACE(" Hierarchies:");
for (i = 0, it = ops->hierarchies; it && *it; it++, i++) {
int j;
char **cit;
printf(" %d: base_cgroup: %s\n", i, (*it)->base_cgroup ? (*it)->base_cgroup : "(null)");
printf(" mountpoint: %s\n", (*it)->mountpoint ? (*it)->mountpoint : "(null)");
printf(" controllers:\n");
TRACE(" %d: base_cgroup: %s", i, (*it)->base_cgroup ? (*it)->base_cgroup : "(null)");
TRACE(" mountpoint: %s", (*it)->mountpoint ? (*it)->mountpoint : "(null)");
TRACE(" controllers:");
for (j = 0, cit = (*it)->controllers; cit && *cit; cit++, j++)
printf(" %d: %s\n", j, *cit);
TRACE(" %d: %s", j, *cit);
}
}
......@@ -1179,491 +1022,155 @@ static void lxc_cgfsng_print_basecg_debuginfo(char *basecginfo, char **klist,
int k;
char **it;
printf("basecginfo is:\n");
printf("%s\n", basecginfo);
TRACE("basecginfo is:");
TRACE("%s", basecginfo);
for (k = 0, it = klist; it && *it; it++, k++)
printf("kernel subsystem %d: %s\n", k, *it);
TRACE("kernel subsystem %d: %s", k, *it);
for (k = 0, it = nlist; it && *it; it++, k++)
printf("named subsystem %d: %s\n", k, *it);
TRACE("named subsystem %d: %s", k, *it);
}
static void lxc_cgfsng_print_debuginfo(const struct cgfsng_handler_data *d)
{
lxc_cgfsng_print_handler_data(d);
lxc_cgfsng_print_hierarchies();
}
/* At startup, parse_hierarchies finds all the info we need about cgroup
* mountpoints and current cgroups, and stores it in @d.
*/
static bool cg_hybrid_init(void)
static int recursive_destroy(char *dirname)
{
int ret;
char *basecginfo;
bool will_escape;
FILE *f;
size_t len = 0;
char *line = NULL;
char **klist = NULL, **nlist = NULL;
/* Root spawned containers escape the current cgroup, so use init's
* cgroups as our base in that case.
*/
will_escape = (geteuid() == 0);
if (will_escape)
basecginfo = read_file("/proc/1/cgroup");
else
basecginfo = read_file("/proc/self/cgroup");
if (!basecginfo)
return false;
ret = get_existing_subsystems(&klist, &nlist);
if (ret < 0) {
CGFSNG_DEBUG("Failed to retrieve available legacy cgroup controllers\n");
free(basecginfo);
return false;
}
f = fopen("/proc/self/mountinfo", "r");
if (!f) {
CGFSNG_DEBUG("Failed to open \"/proc/self/mountinfo\"\n");
free(basecginfo);
return false;
}
if (lxc_cgfsng_debug)
lxc_cgfsng_print_basecg_debuginfo(basecginfo, klist, nlist);
while (getline(&line, &len, f) != -1) {
int type;
bool writeable;
struct hierarchy *new;
char *base_cgroup = NULL, *mountpoint = NULL;
char **controller_list = NULL;
type = get_cgroup_version(line);
if (type == 0)
continue;
struct dirent *direntp;
DIR *dir;
int r = 0;
if (type == CGROUP2_SUPER_MAGIC && unified)
continue;
dir = opendir(dirname);
if (!dir)
return -1;
if (cgroup_layout == CGROUP_LAYOUT_UNKNOWN) {
if (type == CGROUP2_SUPER_MAGIC)
cgroup_layout = CGROUP_LAYOUT_UNIFIED;
else if (type == CGROUP_SUPER_MAGIC)
cgroup_layout = CGROUP_LAYOUT_LEGACY;
} else if (cgroup_layout == CGROUP_LAYOUT_UNIFIED) {
if (type == CGROUP_SUPER_MAGIC)
cgroup_layout = CGROUP_LAYOUT_HYBRID;
} else if (cgroup_layout == CGROUP_LAYOUT_LEGACY) {
if (type == CGROUP2_SUPER_MAGIC)
cgroup_layout = CGROUP_LAYOUT_HYBRID;
}
while ((direntp = readdir(dir))) {
char *pathname;
struct stat mystat;
controller_list = cg_hybrid_get_controllers(klist, nlist, line, type);
if (!controller_list && type == CGROUP_SUPER_MAGIC)
if (!strcmp(direntp->d_name, ".") ||
!strcmp(direntp->d_name, ".."))
continue;
if (type == CGROUP_SUPER_MAGIC)
if (controller_list_is_dup(hierarchies, controller_list))
goto next;
mountpoint = cg_hybrid_get_mountpoint(line);
if (!mountpoint) {
CGFSNG_DEBUG("Failed parsing mountpoint from \"%s\"\n", line);
goto next;
}
pathname = must_make_path(dirname, direntp->d_name, NULL);
if (type == CGROUP_SUPER_MAGIC)
base_cgroup = cg_hybrid_get_current_cgroup(basecginfo, controller_list[0], CGROUP_SUPER_MAGIC);
else
base_cgroup = cg_hybrid_get_current_cgroup(basecginfo, NULL, CGROUP2_SUPER_MAGIC);
if (!base_cgroup) {
CGFSNG_DEBUG("Failed to find current cgroup\n");
ret = lstat(pathname, &mystat);
if (ret < 0) {
if (!r)
WARN("Failed to stat \"%s\"", pathname);
r = -1;
goto next;
}
trim(base_cgroup);
prune_init_scope(base_cgroup);
if (type == CGROUP2_SUPER_MAGIC)
writeable = test_writeable_v2(mountpoint, base_cgroup);
else
writeable = test_writeable_v1(mountpoint, base_cgroup);
if (!writeable)
if (!S_ISDIR(mystat.st_mode))
goto next;
if (type == CGROUP2_SUPER_MAGIC) {
char *cgv2_ctrl_path;
cgv2_ctrl_path = must_make_path(mountpoint, base_cgroup,
"cgroup.controllers",
NULL);
controller_list = cg_unified_get_controllers(cgv2_ctrl_path);
free(cgv2_ctrl_path);
if (!controller_list) {
controller_list = cg_unified_make_empty_controller();
CGFSNG_DEBUG("No controllers are enabled for "
"delegation in the unified hierarchy\n");
}
}
new = add_hierarchy(controller_list, mountpoint, base_cgroup, type);
if (type == CGROUP2_SUPER_MAGIC && !unified)
unified = new;
continue;
ret = recursive_destroy(pathname);
if (ret < 0)
r = -1;
next:
free_string_list(controller_list);
free(mountpoint);
free(base_cgroup);
free(pathname);
}
free_string_list(klist);
free_string_list(nlist);
free(basecginfo);
fclose(f);
free(line);
if (lxc_cgfsng_debug) {
printf("Writable cgroup hierarchies:\n");
lxc_cgfsng_print_hierarchies();
ret = rmdir(dirname);
if (ret < 0) {
if (!r)
WARN("%s - Failed to delete \"%s\"", strerror(errno), dirname);
r = -1;
}
/* verify that all controllers in cgroup.use and all crucial
* controllers are accounted for
*/
if (!all_controllers_found())
return false;
ret = closedir(dir);
if (ret < 0) {
if (!r)
WARN("%s - Failed to delete \"%s\"", strerror(errno), dirname);
r = -1;
}
return true;
return r;
}
static int cg_is_pure_unified(void)
static int cgroup_rmdir(struct hierarchy **hierarchies,
const char *container_cgroup)
{
int i;
int ret;
struct statfs fs;
if (!container_cgroup || !hierarchies)
return 0;
ret = statfs("/sys/fs/cgroup", &fs);
if (ret < 0)
return -ENOMEDIUM;
for (i = 0; hierarchies[i]; i++) {
int ret;
struct hierarchy *h = hierarchies[i];
if (is_fs_type(&fs, CGROUP2_SUPER_MAGIC))
return CGROUP2_SUPER_MAGIC;
if (!h->fullcgpath)
continue;
ret = recursive_destroy(h->fullcgpath);
if (ret < 0)
WARN("Failed to destroy \"%s\"", h->fullcgpath);
free(h->fullcgpath);
h->fullcgpath = NULL;
}
return 0;
}
/* Get current cgroup from /proc/self/cgroup for the cgroupfs v2 hierarchy. */
static char *cg_unified_get_current_cgroup(void)
{
char *basecginfo, *base_cgroup;
bool will_escape;
char *copy = NULL;
struct generic_userns_exec_data {
struct hierarchy **hierarchies;
const char *container_cgroup;
struct lxc_conf *conf;
uid_t origuid; /* target uid in parent namespace */
char *path;
};
will_escape = (geteuid() == 0);
if (will_escape)
basecginfo = read_file("/proc/1/cgroup");
else
basecginfo = read_file("/proc/self/cgroup");
if (!basecginfo)
return NULL;
static int cgroup_rmdir_wrapper(void *data)
{
int ret;
struct generic_userns_exec_data *arg = data;
uid_t nsuid = (arg->conf->root_nsuid_map != NULL) ? 0 : arg->conf->init_uid;
gid_t nsgid = (arg->conf->root_nsgid_map != NULL) ? 0 : arg->conf->init_gid;
base_cgroup = strstr(basecginfo, "0::/");
if (!base_cgroup)
goto cleanup_on_err;
ret = setresgid(nsgid, nsgid, nsgid);
if (ret < 0) {
SYSERROR("Failed to setresgid(%d, %d, %d)", (int)nsgid,
(int)nsgid, (int)nsgid);
return -1;
}
base_cgroup = base_cgroup + 3;
copy = copy_to_eol(base_cgroup);
if (!copy)
goto cleanup_on_err;
ret = setresuid(nsuid, nsuid, nsuid);
if (ret < 0) {
SYSERROR("Failed to setresuid(%d, %d, %d)", (int)nsuid,
(int)nsuid, (int)nsuid);
return -1;
}
cleanup_on_err:
free(basecginfo);
if (copy)
trim(copy);
ret = setgroups(0, NULL);
if (ret < 0 && errno != EPERM) {
SYSERROR("Failed to setgroups(0, NULL)");
return -1;
}
return copy;
return cgroup_rmdir(arg->hierarchies, arg->container_cgroup);
}
static int cg_unified_init(void)
static void cgfsng_destroy(struct cgroup_ops *ops, struct lxc_handler *handler)
{
int ret;
char *mountpoint, *subtree_path;
char **delegatable;
char *base_cgroup = NULL;
ret = cg_is_pure_unified();
if (ret == -ENOMEDIUM)
return -ENOMEDIUM;
if (ret != CGROUP2_SUPER_MAGIC)
return 0;
base_cgroup = cg_unified_get_current_cgroup();
if (!base_cgroup)
return -EINVAL;
prune_init_scope(base_cgroup);
/* We assume that we have already been given controllers to delegate
* further down the hierarchy. If not it is up to the user to delegate
* them to us.
*/
mountpoint = must_copy_string("/sys/fs/cgroup");
subtree_path = must_make_path(mountpoint, base_cgroup,
"cgroup.subtree_control", NULL);
delegatable = cg_unified_get_controllers(subtree_path);
free(subtree_path);
if (!delegatable)
delegatable = cg_unified_make_empty_controller();
if (!delegatable[0])
CGFSNG_DEBUG("No controllers are enabled for delegation\n");
/* TODO: If the user requested specific controllers via lxc.cgroup.use
* we should verify here. The reason I'm not doing it right is that I'm
* not convinced that lxc.cgroup.use will be the future since it is a
* global property. I much rather have an option that lets you request
* controllers per container.
*/
add_hierarchy(delegatable, mountpoint, base_cgroup, CGROUP2_SUPER_MAGIC);
unified = hierarchies[0];
cgroup_layout = CGROUP_LAYOUT_UNIFIED;
return CGROUP2_SUPER_MAGIC;
}
static bool cg_init(void)
{
int ret;
const char *tmp;
errno = 0;
tmp = lxc_global_config_value("lxc.cgroup.use");
if (!cgroup_use && errno != 0) { /* lxc.cgroup.use can be NULL */
CGFSNG_DEBUG("Failed to retrieve list of cgroups to use\n");
return false;
}
cgroup_use = must_copy_string(tmp);
ret = cg_unified_init();
if (ret < 0)
return false;
if (ret == CGROUP2_SUPER_MAGIC)
return true;
return cg_hybrid_init();
}
static void *cgfsng_init(struct lxc_handler *handler)
{
const char *cgroup_pattern;
struct cgfsng_handler_data *d;
d = must_alloc(sizeof(*d));
memset(d, 0, sizeof(*d));
/* copy container name */
d->name = must_copy_string(handler->name);
/* copy per-container cgroup information */
d->cgroup_meta.dir = NULL;
d->cgroup_meta.controllers = NULL;
if (handler->conf) {
d->cgroup_meta.dir = must_copy_string(handler->conf->cgroup_meta.dir);
d->cgroup_meta.controllers = must_copy_string(handler->conf->cgroup_meta.controllers);
}
/* copy system-wide cgroup information */
cgroup_pattern = lxc_global_config_value("lxc.cgroup.pattern");
if (!cgroup_pattern) {
/* lxc.cgroup.pattern is only NULL on error. */
ERROR("Failed to retrieve cgroup pattern");
goto out_free;
}
d->cgroup_pattern = must_copy_string(cgroup_pattern);
d->cgroup_layout = cgroup_layout;
if (d->cgroup_layout == CGROUP_LAYOUT_LEGACY)
TRACE("Running with legacy cgroup layout");
else if (d->cgroup_layout == CGROUP_LAYOUT_HYBRID)
TRACE("Running with hybrid cgroup layout");
else if (d->cgroup_layout == CGROUP_LAYOUT_UNIFIED)
TRACE("Running with unified cgroup layout");
else
WARN("Running with unknown cgroup layout");
if (lxc_cgfsng_debug)
lxc_cgfsng_print_debuginfo(d);
return d;
out_free:
free_handler_data(d);
return NULL;
}
static int recursive_destroy(char *dirname)
{
int ret;
struct dirent *direntp;
DIR *dir;
int r = 0;
dir = opendir(dirname);
if (!dir)
return -1;
while ((direntp = readdir(dir))) {
char *pathname;
struct stat mystat;
if (!strcmp(direntp->d_name, ".") ||
!strcmp(direntp->d_name, ".."))
continue;
pathname = must_make_path(dirname, direntp->d_name, NULL);
ret = lstat(pathname, &mystat);
if (ret < 0) {
if (!r)
WARN("Failed to stat \"%s\"", pathname);
r = -1;
goto next;
}
if (!S_ISDIR(mystat.st_mode))
goto next;
ret = recursive_destroy(pathname);
if (ret < 0)
r = -1;
next:
free(pathname);
}
ret = rmdir(dirname);
if (ret < 0) {
if (!r)
WARN("%s - Failed to delete \"%s\"", strerror(errno), dirname);
r = -1;
}
ret = closedir(dir);
if (ret < 0) {
if (!r)
WARN("%s - Failed to delete \"%s\"", strerror(errno), dirname);
r = -1;
}
return r;
}
static int cgroup_rmdir(char *container_cgroup)
{
int i;
if (!container_cgroup || !hierarchies)
return 0;
for (i = 0; hierarchies[i]; i++) {
int ret;
struct hierarchy *h = hierarchies[i];
if (!h->fullcgpath)
continue;
ret = recursive_destroy(h->fullcgpath);
if (ret < 0)
WARN("Failed to destroy \"%s\"", h->fullcgpath);
free(h->fullcgpath);
h->fullcgpath = NULL;
}
return 0;
}
struct generic_userns_exec_data {
struct cgfsng_handler_data *d;
struct lxc_conf *conf;
uid_t origuid; /* target uid in parent namespace */
char *path;
};
static int cgroup_rmdir_wrapper(void *data)
{
int ret;
struct generic_userns_exec_data *arg = data;
uid_t nsuid = (arg->conf->root_nsuid_map != NULL) ? 0 : arg->conf->init_uid;
gid_t nsgid = (arg->conf->root_nsgid_map != NULL) ? 0 : arg->conf->init_gid;
ret = setresgid(nsgid, nsgid, nsgid);
if (ret < 0) {
SYSERROR("Failed to setresgid(%d, %d, %d)", (int)nsgid,
(int)nsgid, (int)nsgid);
return -1;
}
ret = setresuid(nsuid, nsuid, nsuid);
if (ret < 0) {
SYSERROR("Failed to setresuid(%d, %d, %d)", (int)nsuid,
(int)nsuid, (int)nsuid);
return -1;
}
ret = setgroups(0, NULL);
if (ret < 0 && errno != EPERM) {
SYSERROR("Failed to setgroups(0, NULL)");
return -1;
}
return cgroup_rmdir(arg->d->container_cgroup);
}
static void cgfsng_destroy(void *hdata, struct lxc_conf *conf)
{
int ret;
struct cgfsng_handler_data *d = hdata;
struct generic_userns_exec_data wrap;
if (!d)
return;
struct generic_userns_exec_data wrap;
wrap.origuid = 0;
wrap.d = hdata;
wrap.conf = conf;
wrap.container_cgroup = ops->container_cgroup;
wrap.hierarchies = ops->hierarchies;
wrap.conf = handler->conf;
if (conf && !lxc_list_empty(&conf->id_map))
ret = userns_exec_1(conf, cgroup_rmdir_wrapper, &wrap,
if (handler->conf && !lxc_list_empty(&handler->conf->id_map))
ret = userns_exec_1(handler->conf, cgroup_rmdir_wrapper, &wrap,
"cgroup_rmdir_wrapper");
else
ret = cgroup_rmdir(d->container_cgroup);
ret = cgroup_rmdir(ops->hierarchies, ops->container_cgroup);
if (ret < 0) {
WARN("Failed to destroy cgroups");
return;
}
free_handler_data(d);
}
struct cgroup_ops *cgfsng_ops_init(void)
{
if (getenv("LXC_DEBUG_CGFSNG"))
lxc_cgfsng_debug = true;
if (!cg_init())
return NULL;
return &cgfsng_ops;
}
static bool cg_unified_create_cgroup(struct hierarchy *h, char *cgname)
......@@ -1769,26 +1276,28 @@ static void remove_path_for_hierarchy(struct hierarchy *h, char *cgname)
/* Try to create the same cgroup in all hierarchies. Start with cgroup_pattern;
* next cgroup_pattern-1, -2, ..., -999.
*/
static inline bool cgfsng_create(void *hdata)
static inline bool cgfsng_create(struct cgroup_ops *ops,
struct lxc_handler *handler)
{
int i;
size_t len;
char *container_cgroup, *offset, *tmp;
int idx = 0;
struct cgfsng_handler_data *d = hdata;
struct lxc_conf *conf = handler->conf;
const char *join_args[] = {conf->cgroup_meta.dir, handler->name, NULL};
if (!d)
if (ops->container_cgroup) {
WARN("cgfsng_create called a second time: %s", ops->container_cgroup);
return false;
}
if (d->container_cgroup) {
WARN("cgfsng_create called a second time");
if (!conf)
return false;
}
if (d->cgroup_meta.dir)
tmp = lxc_string_join("/", (const char *[]){d->cgroup_meta.dir, d->name, NULL}, false);
if (conf->cgroup_meta.dir)
tmp = lxc_string_join("/", join_args, false);
else
tmp = lxc_string_replace("%n", d->name, d->cgroup_pattern);
tmp = lxc_string_replace("%n", handler->name, ops->cgroup_pattern);
if (!tmp) {
ERROR("Failed expanding cgroup name pattern");
return false;
......@@ -1820,20 +1329,20 @@ again:
}
}
for (i = 0; hierarchies[i]; i++) {
if (!create_path_for_hierarchy(hierarchies[i], container_cgroup)) {
for (i = 0; ops->hierarchies[i]; i++) {
if (!create_path_for_hierarchy(ops->hierarchies[i], container_cgroup)) {
int j;
ERROR("Failed to create cgroup \"%s\"", hierarchies[i]->fullcgpath);
free(hierarchies[i]->fullcgpath);
hierarchies[i]->fullcgpath = NULL;
ERROR("Failed to create cgroup \"%s\"", ops->hierarchies[i]->fullcgpath);
free(ops->hierarchies[i]->fullcgpath);
ops->hierarchies[i]->fullcgpath = NULL;
for (j = 0; j < i; j++)
remove_path_for_hierarchy(hierarchies[j], container_cgroup);
remove_path_for_hierarchy(ops->hierarchies[j], container_cgroup);
idx++;
goto again;
}
}
d->container_cgroup = container_cgroup;
ops->container_cgroup = container_cgroup;
return true;
......@@ -1843,7 +1352,7 @@ out_free:
return false;
}
static bool cgfsng_enter(void *hdata, pid_t pid)
static bool cgfsng_enter(struct cgroup_ops *ops, pid_t pid)
{
int i, len;
char pidstr[25];
......@@ -1852,11 +1361,11 @@ static bool cgfsng_enter(void *hdata, pid_t pid)
if (len < 0 || len >= 25)
return false;
for (i = 0; hierarchies[i]; i++) {
for (i = 0; ops->hierarchies[i]; i++) {
int ret;
char *fullpath;
fullpath = must_make_path(hierarchies[i]->fullcgpath,
fullpath = must_make_path(ops->hierarchies[i]->fullcgpath,
"cgroup.procs", NULL);
ret = lxc_write_to_file(fullpath, pidstr, len, false, 0666);
if (ret != 0) {
......@@ -1929,9 +1438,9 @@ static int chown_cgroup_wrapper(void *data)
destuid = get_ns_uid(arg->origuid);
for (i = 0; hierarchies[i]; i++) {
for (i = 0; arg->hierarchies[i]; i++) {
char *fullpath;
char *path = hierarchies[i]->fullcgpath;
char *path = arg->hierarchies[i]->fullcgpath;
ret = chowmod(path, destuid, nsgid, 0775);
if (ret < 0)
......@@ -1944,17 +1453,17 @@ static int chown_cgroup_wrapper(void *data)
* files (which systemd in wily insists on doing).
*/
if (hierarchies[i]->version == CGROUP_SUPER_MAGIC) {
if (arg->hierarchies[i]->version == CGROUP_SUPER_MAGIC) {
fullpath = must_make_path(path, "tasks", NULL);
(void)chowmod(fullpath, destuid, nsgid, 0664);
free(fullpath);
}
fullpath = must_make_path(path, "cgroup.procs", NULL);
(void)chowmod(fullpath, destuid, 0, 0664);
(void)chowmod(fullpath, destuid, nsgid, 0664);
free(fullpath);
if (hierarchies[i]->version != CGROUP2_SUPER_MAGIC)
if (arg->hierarchies[i]->version != CGROUP2_SUPER_MAGIC)
continue;
fullpath = must_make_path(path, "cgroup.subtree_control", NULL);
......@@ -1969,20 +1478,16 @@ static int chown_cgroup_wrapper(void *data)
return 0;
}
static bool cgfsng_chown(void *hdata, struct lxc_conf *conf)
static bool cgfsng_chown(struct cgroup_ops *ops, struct lxc_conf *conf)
{
struct cgfsng_handler_data *d = hdata;
struct generic_userns_exec_data wrap;
if (!d)
return false;
if (lxc_list_empty(&conf->id_map))
return true;
wrap.origuid = geteuid();
wrap.path = NULL;
wrap.d = d;
wrap.hierarchies = ops->hierarchies;
wrap.conf = conf;
if (userns_exec_1(conf, chown_cgroup_wrapper, &wrap,
......@@ -2122,13 +1627,12 @@ static inline int cg_mount_cgroup_full(int type, struct hierarchy *h,
return __cg_mount_direct(type, h, controllerpath);
}
static bool cgfsng_mount(void *hdata, const char *root, int type)
static bool cgfsng_mount(struct cgroup_ops *ops, struct lxc_handler *handler,
const char *root, int type)
{
int i, ret;
char *tmpfspath = NULL;
bool has_cgns = false, retval = false, wants_force_mount = false;
struct lxc_handler *handler = hdata;
struct cgfsng_handler_data *d = handler->cgroup_data;
if ((type & LXC_AUTO_CGROUP_MASK) == 0)
return true;
......@@ -2162,9 +1666,9 @@ static bool cgfsng_mount(void *hdata, const char *root, int type)
if (ret < 0)
goto on_error;
for (i = 0; hierarchies[i]; i++) {
for (i = 0; ops->hierarchies[i]; i++) {
char *controllerpath, *path2;
struct hierarchy *h = hierarchies[i];
struct hierarchy *h = ops->hierarchies[i];
char *controller = strrchr(h->mountpoint, '/');
if (!controller)
......@@ -2209,7 +1713,7 @@ static bool cgfsng_mount(void *hdata, const char *root, int type)
}
path2 = must_make_path(controllerpath, h->base_cgroup,
d->container_cgroup, NULL);
ops->container_cgroup, NULL);
ret = mkdir_p(path2, 0755);
if (ret < 0) {
free(controllerpath);
......@@ -2218,7 +1722,7 @@ static bool cgfsng_mount(void *hdata, const char *root, int type)
}
ret = cg_legacy_mount_controllers(type, h, controllerpath,
path2, d->container_cgroup);
path2, ops->container_cgroup);
free(controllerpath);
free(path2);
if (ret < 0)
......@@ -2276,35 +1780,34 @@ static int recursive_count_nrtasks(char *dirname)
return count;
}
static int cgfsng_nrtasks(void *hdata)
static int cgfsng_nrtasks(struct cgroup_ops *ops)
{
int count;
char *path;
struct cgfsng_handler_data *d = hdata;
if (!d || !d->container_cgroup || !hierarchies)
if (!ops->container_cgroup || !ops->hierarchies)
return -1;
path = must_make_path(hierarchies[0]->fullcgpath, NULL);
path = must_make_path(ops->hierarchies[0]->fullcgpath, NULL);
count = recursive_count_nrtasks(path);
free(path);
return count;
}
/* Only root needs to escape to the cgroup of its init. */
static bool cgfsng_escape()
static bool cgfsng_escape(const struct cgroup_ops *ops)
{
int i;
if (geteuid())
return true;
for (i = 0; hierarchies[i]; i++) {
for (i = 0; ops->hierarchies[i]; i++) {
int ret;
char *fullpath;
fullpath = must_make_path(hierarchies[i]->mountpoint,
hierarchies[i]->base_cgroup,
fullpath = must_make_path(ops->hierarchies[i]->mountpoint,
ops->hierarchies[i]->base_cgroup,
"cgroup.procs", NULL);
ret = lxc_write_to_file(fullpath, "0", 2, false, 0666);
if (ret != 0) {
......@@ -2318,26 +1821,26 @@ static bool cgfsng_escape()
return true;
}
static int cgfsng_num_hierarchies(void)
static int cgfsng_num_hierarchies(struct cgroup_ops *ops)
{
int i;
for (i = 0; hierarchies[i]; i++)
for (i = 0; ops->hierarchies[i]; i++)
;
return i;
}
static bool cgfsng_get_hierarchies(int n, char ***out)
static bool cgfsng_get_hierarchies(struct cgroup_ops *ops, int n, char ***out)
{
int i;
/* sanity check n */
for (i = 0; i < n; i++)
if (!hierarchies[i])
if (!ops->hierarchies[i])
return false;
*out = hierarchies[i]->controllers;
*out = ops->hierarchies[i]->controllers;
return true;
}
......@@ -2348,13 +1851,13 @@ static bool cgfsng_get_hierarchies(int n, char ***out)
/* TODO: If the unified cgroup hierarchy grows a freezer controller this needs
* to be adapted.
*/
static bool cgfsng_unfreeze(void *hdata)
static bool cgfsng_unfreeze(struct cgroup_ops *ops)
{
int ret;
char *fullpath;
struct hierarchy *h;
h = get_hierarchy("freezer");
h = get_hierarchy(ops, "freezer");
if (!h)
return false;
......@@ -2367,14 +1870,15 @@ static bool cgfsng_unfreeze(void *hdata)
return true;
}
static const char *cgfsng_get_cgroup(void *hdata, const char *controller)
static const char *cgfsng_get_cgroup(struct cgroup_ops *ops,
const char *controller)
{
struct hierarchy *h;
h = get_hierarchy(controller);
h = get_hierarchy(ops, controller);
if (!h) {
SYSERROR("Failed to find hierarchy for controller \"%s\"",
controller ? controller : "(null)");
WARN("Failed to find hierarchy for controller \"%s\"",
controller ? controller : "(null)");
return NULL;
}
......@@ -2465,7 +1969,8 @@ on_error:
return fret;
}
static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
static bool cgfsng_attach(struct cgroup_ops *ops, const char *name,
const char *lxcpath, pid_t pid)
{
int i, len, ret;
char pidstr[25];
......@@ -2474,10 +1979,10 @@ static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
if (len < 0 || len >= 25)
return false;
for (i = 0; hierarchies[i]; i++) {
for (i = 0; ops->hierarchies[i]; i++) {
char *path;
char *fullpath = NULL;
struct hierarchy *h = hierarchies[i];
struct hierarchy *h = ops->hierarchies[i];
if (h->version == CGROUP2_SUPER_MAGIC) {
ret = __cg_unified_attach(h, name, lxcpath, pidstr, len,
......@@ -2511,8 +2016,8 @@ static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
* don't have a cgroup_data set up, so we ask the running container through the
* commands API for the cgroup path.
*/
static int cgfsng_get(const char *filename, char *value, size_t len,
const char *name, const char *lxcpath)
static int cgfsng_get(struct cgroup_ops *ops, const char *filename, char *value,
size_t len, const char *name, const char *lxcpath)
{
int ret = -1;
size_t controller_len;
......@@ -2531,7 +2036,7 @@ static int cgfsng_get(const char *filename, char *value, size_t len,
if (!path)
return -1;
h = get_hierarchy(controller);
h = get_hierarchy(ops, controller);
if (h) {
char *fullpath;
......@@ -2548,8 +2053,8 @@ static int cgfsng_get(const char *filename, char *value, size_t len,
* don't have a cgroup_data set up, so we ask the running container through the
* commands API for the cgroup path.
*/
static int cgfsng_set(const char *filename, const char *value, const char *name,
const char *lxcpath)
static int cgfsng_set(struct cgroup_ops *ops, const char *filename,
const char *value, const char *name, const char *lxcpath)
{
int ret = -1;
size_t controller_len;
......@@ -2568,7 +2073,7 @@ static int cgfsng_set(const char *filename, const char *value, const char *name,
if (!path)
return -1;
h = get_hierarchy(controller);
h = get_hierarchy(ops, controller);
if (h) {
char *fullpath;
......@@ -2662,8 +2167,8 @@ out:
/* Called from setup_limits - here we have the container's cgroup_data because
* we created the cgroups.
*/
static int cg_legacy_set_data(const char *filename, const char *value,
struct cgfsng_handler_data *d)
static int cg_legacy_set_data(struct cgroup_ops *ops, const char *filename,
const char *value)
{
size_t len;
char *fullpath, *p;
......@@ -2687,7 +2192,7 @@ static int cg_legacy_set_data(const char *filename, const char *value,
value = converted_value;
}
h = get_hierarchy(controller);
h = get_hierarchy(ops, controller);
if (!h) {
ERROR("Failed to setup limits for the \"%s\" controller. "
"The controller seems to be unused by \"cgfsng\" cgroup "
......@@ -2703,13 +2208,12 @@ static int cg_legacy_set_data(const char *filename, const char *value,
return ret;
}
static bool __cg_legacy_setup_limits(void *hdata,
static bool __cg_legacy_setup_limits(struct cgroup_ops *ops,
struct lxc_list *cgroup_settings,
bool do_devices)
{
struct lxc_list *iterator, *next, *sorted_cgroup_settings;
struct lxc_cgroup *cg;
struct cgfsng_handler_data *d = hdata;
bool ret = false;
if (lxc_list_empty(cgroup_settings))
......@@ -2723,7 +2227,7 @@ static bool __cg_legacy_setup_limits(void *hdata,
cg = iterator->elem;
if (do_devices == !strncmp("devices", cg->subsystem, 7)) {
if (cg_legacy_set_data(cg->subsystem, cg->value, d)) {
if (cg_legacy_set_data(ops, cg->subsystem, cg->value)) {
if (do_devices && (errno == EACCES || errno == EPERM)) {
WARN("Failed to set \"%s\" to \"%s\"",
cg->subsystem, cg->value);
......@@ -2749,11 +2253,11 @@ out:
return ret;
}
static bool __cg_unified_setup_limits(void *hdata,
static bool __cg_unified_setup_limits(struct cgroup_ops *ops,
struct lxc_list *cgroup_settings)
{
struct lxc_list *iterator;
struct hierarchy *h = unified;
struct hierarchy *h = ops->unified;
if (lxc_list_empty(cgroup_settings))
return true;
......@@ -2781,35 +2285,328 @@ static bool __cg_unified_setup_limits(void *hdata,
return true;
}
static bool cgfsng_setup_limits(void *hdata, struct lxc_conf *conf,
static bool cgfsng_setup_limits(struct cgroup_ops *ops, struct lxc_conf *conf,
bool do_devices)
{
bool bret;
bret = __cg_legacy_setup_limits(hdata, &conf->cgroup, do_devices);
bret = __cg_legacy_setup_limits(ops, &conf->cgroup, do_devices);
if (!bret)
return false;
return __cg_unified_setup_limits(hdata, &conf->cgroup2);
}
static struct cgroup_ops cgfsng_ops = {
.init = cgfsng_init,
.destroy = cgfsng_destroy,
.create = cgfsng_create,
.enter = cgfsng_enter,
.escape = cgfsng_escape,
.num_hierarchies = cgfsng_num_hierarchies,
.get_hierarchies = cgfsng_get_hierarchies,
.get_cgroup = cgfsng_get_cgroup,
.get = cgfsng_get,
.set = cgfsng_set,
.unfreeze = cgfsng_unfreeze,
.setup_limits = cgfsng_setup_limits,
.driver = "cgfsng",
.version = "1.0.0",
.attach = cgfsng_attach,
.chown = cgfsng_chown,
.mount_cgroup = cgfsng_mount,
.nrtasks = cgfsng_nrtasks,
};
return __cg_unified_setup_limits(ops, &conf->cgroup2);
}
/* At startup, parse_hierarchies finds all the info we need about cgroup
* mountpoints and current cgroups, and stores it in @d.
*/
static bool cg_hybrid_init(struct cgroup_ops *ops)
{
int ret;
char *basecginfo;
bool will_escape;
FILE *f;
size_t len = 0;
char *line = NULL;
char **klist = NULL, **nlist = NULL;
/* Root spawned containers escape the current cgroup, so use init's
* cgroups as our base in that case.
*/
will_escape = (geteuid() == 0);
if (will_escape)
basecginfo = read_file("/proc/1/cgroup");
else
basecginfo = read_file("/proc/self/cgroup");
if (!basecginfo)
return false;
ret = get_existing_subsystems(&klist, &nlist);
if (ret < 0) {
ERROR("Failed to retrieve available legacy cgroup controllers");
free(basecginfo);
return false;
}
f = fopen("/proc/self/mountinfo", "r");
if (!f) {
ERROR("Failed to open \"/proc/self/mountinfo\"");
free(basecginfo);
return false;
}
lxc_cgfsng_print_basecg_debuginfo(basecginfo, klist, nlist);
while (getline(&line, &len, f) != -1) {
int type;
bool writeable;
struct hierarchy *new;
char *base_cgroup = NULL, *mountpoint = NULL;
char **controller_list = NULL;
type = get_cgroup_version(line);
if (type == 0)
continue;
if (type == CGROUP2_SUPER_MAGIC && ops->unified)
continue;
if (ops->cgroup_layout == CGROUP_LAYOUT_UNKNOWN) {
if (type == CGROUP2_SUPER_MAGIC)
ops->cgroup_layout = CGROUP_LAYOUT_UNIFIED;
else if (type == CGROUP_SUPER_MAGIC)
ops->cgroup_layout = CGROUP_LAYOUT_LEGACY;
} else if (ops->cgroup_layout == CGROUP_LAYOUT_UNIFIED) {
if (type == CGROUP_SUPER_MAGIC)
ops->cgroup_layout = CGROUP_LAYOUT_HYBRID;
} else if (ops->cgroup_layout == CGROUP_LAYOUT_LEGACY) {
if (type == CGROUP2_SUPER_MAGIC)
ops->cgroup_layout = CGROUP_LAYOUT_HYBRID;
}
controller_list = cg_hybrid_get_controllers(klist, nlist, line, type);
if (!controller_list && type == CGROUP_SUPER_MAGIC)
continue;
if (type == CGROUP_SUPER_MAGIC)
if (controller_list_is_dup(ops->hierarchies, controller_list))
goto next;
mountpoint = cg_hybrid_get_mountpoint(line);
if (!mountpoint) {
ERROR("Failed parsing mountpoint from \"%s\"", line);
goto next;
}
if (type == CGROUP_SUPER_MAGIC)
base_cgroup = cg_hybrid_get_current_cgroup(basecginfo, controller_list[0], CGROUP_SUPER_MAGIC);
else
base_cgroup = cg_hybrid_get_current_cgroup(basecginfo, NULL, CGROUP2_SUPER_MAGIC);
if (!base_cgroup) {
ERROR("Failed to find current cgroup");
goto next;
}
trim(base_cgroup);
prune_init_scope(base_cgroup);
if (type == CGROUP2_SUPER_MAGIC)
writeable = test_writeable_v2(mountpoint, base_cgroup);
else
writeable = test_writeable_v1(mountpoint, base_cgroup);
if (!writeable)
goto next;
if (type == CGROUP2_SUPER_MAGIC) {
char *cgv2_ctrl_path;
cgv2_ctrl_path = must_make_path(mountpoint, base_cgroup,
"cgroup.controllers",
NULL);
controller_list = cg_unified_get_controllers(cgv2_ctrl_path);
free(cgv2_ctrl_path);
if (!controller_list) {
controller_list = cg_unified_make_empty_controller();
TRACE("No controllers are enabled for "
"delegation in the unified hierarchy");
}
}
new = add_hierarchy(&ops->hierarchies, controller_list, mountpoint, base_cgroup, type);
if (type == CGROUP2_SUPER_MAGIC && !ops->unified)
ops->unified = new;
continue;
next:
free_string_list(controller_list);
free(mountpoint);
free(base_cgroup);
}
free_string_list(klist);
free_string_list(nlist);
free(basecginfo);
fclose(f);
free(line);
TRACE("Writable cgroup hierarchies:");
lxc_cgfsng_print_hierarchies(ops);
/* verify that all controllers in cgroup.use and all crucial
* controllers are accounted for
*/
if (!all_controllers_found(ops))
return false;
return true;
}
static int cg_is_pure_unified(void)
{
int ret;
struct statfs fs;
ret = statfs("/sys/fs/cgroup", &fs);
if (ret < 0)
return -ENOMEDIUM;
if (is_fs_type(&fs, CGROUP2_SUPER_MAGIC))
return CGROUP2_SUPER_MAGIC;
return 0;
}
/* Get current cgroup from /proc/self/cgroup for the cgroupfs v2 hierarchy. */
static char *cg_unified_get_current_cgroup(void)
{
char *basecginfo, *base_cgroup;
bool will_escape;
char *copy = NULL;
will_escape = (geteuid() == 0);
if (will_escape)
basecginfo = read_file("/proc/1/cgroup");
else
basecginfo = read_file("/proc/self/cgroup");
if (!basecginfo)
return NULL;
base_cgroup = strstr(basecginfo, "0::/");
if (!base_cgroup)
goto cleanup_on_err;
base_cgroup = base_cgroup + 3;
copy = copy_to_eol(base_cgroup);
if (!copy)
goto cleanup_on_err;
cleanup_on_err:
free(basecginfo);
if (copy)
trim(copy);
return copy;
}
static int cg_unified_init(struct cgroup_ops *ops)
{
int ret;
char *mountpoint, *subtree_path;
char **delegatable;
char *base_cgroup = NULL;
ret = cg_is_pure_unified();
if (ret == -ENOMEDIUM)
return -ENOMEDIUM;
if (ret != CGROUP2_SUPER_MAGIC)
return 0;
base_cgroup = cg_unified_get_current_cgroup();
if (!base_cgroup)
return -EINVAL;
prune_init_scope(base_cgroup);
/* We assume that we have already been given controllers to delegate
* further down the hierarchy. If not it is up to the user to delegate
* them to us.
*/
mountpoint = must_copy_string("/sys/fs/cgroup");
subtree_path = must_make_path(mountpoint, base_cgroup,
"cgroup.subtree_control", NULL);
delegatable = cg_unified_get_controllers(subtree_path);
free(subtree_path);
if (!delegatable)
delegatable = cg_unified_make_empty_controller();
if (!delegatable[0])
TRACE("No controllers are enabled for delegation");
/* TODO: If the user requested specific controllers via lxc.cgroup.use
* we should verify here. The reason I'm not doing it right is that I'm
* not convinced that lxc.cgroup.use will be the future since it is a
* global property. I much rather have an option that lets you request
* controllers per container.
*/
add_hierarchy(&ops->hierarchies, delegatable, mountpoint, base_cgroup, CGROUP2_SUPER_MAGIC);
ops->cgroup_layout = CGROUP_LAYOUT_UNIFIED;
return CGROUP2_SUPER_MAGIC;
}
static bool cg_init(struct cgroup_ops *ops)
{
int ret;
const char *tmp;
tmp = lxc_global_config_value("lxc.cgroup.use");
if (tmp)
ops->cgroup_use = must_copy_string(tmp);
ret = cg_unified_init(ops);
if (ret < 0)
return false;
if (ret == CGROUP2_SUPER_MAGIC)
return true;
return cg_hybrid_init(ops);
}
static bool cgfsng_data_init(struct cgroup_ops *ops)
{
const char *cgroup_pattern;
/* copy system-wide cgroup information */
cgroup_pattern = lxc_global_config_value("lxc.cgroup.pattern");
if (!cgroup_pattern) {
/* lxc.cgroup.pattern is only NULL on error. */
ERROR("Failed to retrieve cgroup pattern");
return false;
}
ops->cgroup_pattern = must_copy_string(cgroup_pattern);
return true;
}
struct cgroup_ops *cgfsng_ops_init(void)
{
struct cgroup_ops *cgfsng_ops;
cgfsng_ops = malloc(sizeof(struct cgroup_ops));
if (!cgfsng_ops)
return NULL;
memset(cgfsng_ops, 0, sizeof(struct cgroup_ops));
cgfsng_ops->cgroup_layout = CGROUP_LAYOUT_UNKNOWN;
if (!cg_init(cgfsng_ops)) {
free(cgfsng_ops);
return NULL;
}
cgfsng_ops->data_init = cgfsng_data_init;
cgfsng_ops->destroy = cgfsng_destroy;
cgfsng_ops->create = cgfsng_create;
cgfsng_ops->enter = cgfsng_enter;
cgfsng_ops->escape = cgfsng_escape;
cgfsng_ops->num_hierarchies = cgfsng_num_hierarchies;
cgfsng_ops->get_hierarchies = cgfsng_get_hierarchies;
cgfsng_ops->get_cgroup = cgfsng_get_cgroup;
cgfsng_ops->get = cgfsng_get;
cgfsng_ops->set = cgfsng_set;
cgfsng_ops->unfreeze = cgfsng_unfreeze;
cgfsng_ops->setup_limits = cgfsng_setup_limits;
cgfsng_ops->driver = "cgfsng";
cgfsng_ops->version = "1.0.0";
cgfsng_ops->attach = cgfsng_attach;
cgfsng_ops->chown = cgfsng_chown;
cgfsng_ops->mount = cgfsng_mount;
cgfsng_ops->nrtasks = cgfsng_nrtasks;
return cgfsng_ops;
}
src/lxc/cgroups/cgroup.c
......@@ -32,180 +32,61 @@
lxc_log_define(lxc_cgroup, lxc);
static struct cgroup_ops *ops = NULL;
extern struct cgroup_ops *cgfsng_ops_init(void);
__attribute__((constructor)) void cgroup_ops_init(void)
struct cgroup_ops *cgroup_init(struct lxc_handler *handler)
{
if (ops) {
INFO("Running with %s in version %s", ops->driver, ops->version);
return;
}
DEBUG("cgroup_init");
ops = cgfsng_ops_init();
if (ops)
INFO("Initialized cgroup driver %s", ops->driver);
}
struct cgroup_ops *cgroup_ops;
bool cgroup_init(struct lxc_handler *handler)
{
if (handler->cgroup_data) {
ERROR("cgroup_init called on already initialized handler");
return true;
cgroup_ops = cgfsng_ops_init();
if (!cgroup_ops) {
ERROR("Failed to initialize cgroup driver");
return NULL;
}
if (ops) {
INFO("cgroup driver %s initing for %s", ops->driver, handler->name);
handler->cgroup_data = ops->init(handler);
}
if (!cgroup_ops->data_init(cgroup_ops))
return NULL;
return handler->cgroup_data != NULL;
}
TRACE("Initialized cgroup driver %s", cgroup_ops->driver);
void cgroup_destroy(struct lxc_handler *handler)
{
if (ops) {
ops->destroy(handler->cgroup_data, handler->conf);
handler->cgroup_data = NULL;
}
}
if (cgroup_ops->cgroup_layout == CGROUP_LAYOUT_LEGACY)
TRACE("Running with legacy cgroup layout");
else if (cgroup_ops->cgroup_layout == CGROUP_LAYOUT_HYBRID)
TRACE("Running with hybrid cgroup layout");
else if (cgroup_ops->cgroup_layout == CGROUP_LAYOUT_UNIFIED)
TRACE("Running with unified cgroup layout");
else
WARN("Running with unknown cgroup layout");
/* Create the container cgroups for all requested controllers. */
bool cgroup_create(struct lxc_handler *handler)
{
if (ops)
return ops->create(handler->cgroup_data);
return false;
return cgroup_ops;
}
/* Enter the container init into its new cgroups for all requested controllers. */
bool cgroup_enter(struct lxc_handler *handler)
void cgroup_exit(struct cgroup_ops *ops)
{
if (ops)
return ops->enter(handler->cgroup_data, handler->pid);
struct hierarchy **it;
return false;
}
bool cgroup_create_legacy(struct lxc_handler *handler)
{
if (ops && ops->create_legacy)
return ops->create_legacy(handler->cgroup_data, handler->pid);
return true;
}
const char *cgroup_get_cgroup(struct lxc_handler *handler,
const char *subsystem)
{
if (ops)
return ops->get_cgroup(handler->cgroup_data, subsystem);
return NULL;
}
bool cgroup_escape(struct lxc_handler *handler)
{
if (ops)
return ops->escape(handler->cgroup_data);
return false;
}
int cgroup_num_hierarchies(void)
{
if (!ops)
return -1;
return ops->num_hierarchies();
}
bool cgroup_get_hierarchies(int n, char ***out)
{
if (!ops)
return false;
return ops->get_hierarchies(n, out);
}
bool cgroup_unfreeze(struct lxc_handler *handler)
{
if (ops)
return ops->unfreeze(handler->cgroup_data);
return false;
}
bool cgroup_setup_limits(struct lxc_handler *handler, bool with_devices)
{
if (ops)
return ops->setup_limits(handler->cgroup_data,
handler->conf, with_devices);
return false;
}
return;
bool cgroup_chown(struct lxc_handler *handler)
{
if (ops && ops->chown)
return ops->chown(handler->cgroup_data, handler->conf);
free(ops->cgroup_use);
free(ops->cgroup_pattern);
free(ops->container_cgroup);
return true;
}
for (it = ops->hierarchies; it && *it; it++) {
char **ctrlr;
bool cgroup_mount(const char *root, struct lxc_handler *handler, int type)
{
if (ops)
return ops->mount_cgroup(handler, root, type);
return false;
}
for (ctrlr = (*it)->controllers; ctrlr && *ctrlr; ctrlr++)
free(*ctrlr);
free((*it)->controllers);
int cgroup_nrtasks(struct lxc_handler *handler)
{
if (ops) {
if (ops->nrtasks)
return ops->nrtasks(handler->cgroup_data);
else
WARN("cgroup driver \"%s\" doesn't implement nrtasks", ops->driver);
free((*it)->mountpoint);
free((*it)->base_cgroup);
free((*it)->fullcgpath);
free(*it);
}
free(ops->hierarchies);
return -1;
}
bool cgroup_attach(const char *name, const char *lxcpath, pid_t pid)
{
if (ops)
return ops->attach(name, lxcpath, pid);
return false;
}
int lxc_cgroup_set(const char *filename, const char *value, const char *name,
const char *lxcpath)
{
if (ops)
return ops->set(filename, value, name, lxcpath);
return -1;
}
int lxc_cgroup_get(const char *filename, char *value, size_t len,
const char *name, const char *lxcpath)
{
if (ops)
return ops->get(filename, value, len, name, lxcpath);
return -1;
}
void cgroup_disconnect(void)
{
if (ops && ops->disconnect)
ops->disconnect();
return;
}
#define INIT_SCOPE "/init.scope"
......
src/lxc/cgroups/cgroup.h
......@@ -39,48 +39,114 @@ typedef enum {
CGROUP_LAYOUT_UNIFIED = 2,
} cgroup_layout_t;
/* A descriptor for a mounted hierarchy
*
* @controllers
* - legacy hierarchy
* Either NULL, or a null-terminated list of all the co-mounted controllers.
* - unified hierarchy
* Either NULL, or a null-terminated list of all enabled controllers.
*
* @mountpoint
* - The mountpoint we will use.
* - legacy hierarchy
* It will be either /sys/fs/cgroup/controller or
* /sys/fs/cgroup/controllerlist.
* - unified hierarchy
* It will either be /sys/fs/cgroup or /sys/fs/cgroup/<mountpoint-name>
* depending on whether this is a hybrid cgroup layout (mix of legacy and
* unified hierarchies) or a pure unified cgroup layout.
*
* @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).
*
* @fullcgpath
* - The full path to the containers cgroup.
*
* @version
* - legacy hierarchy
* If the hierarchy is a legacy hierarchy this will be set to
* CGROUP_SUPER_MAGIC.
* - unified hierarchy
* If the hierarchy is a legacy hierarchy this will be set to
* CGROUP2_SUPER_MAGIC.
*/
struct hierarchy {
char **controllers;
char *mountpoint;
char *base_cgroup;
char *fullcgpath;
int version;
};
struct cgroup_ops {
/* string constant */
const char *driver;
/* string constant */
const char *version;
void *(*init)(struct lxc_handler *handler);
void (*destroy)(void *hdata, struct lxc_conf *conf);
bool (*create)(void *hdata);
bool (*enter)(void *hdata, pid_t pid);
bool (*create_legacy)(void *hdata, pid_t pid);
const char *(*get_cgroup)(void *hdata, const char *subsystem);
bool (*escape)();
int (*num_hierarchies)();
bool (*get_hierarchies)(int n, char ***out);
int (*set)(const char *filename, const char *value, const char *name, const char *lxcpath);
int (*get)(const char *filename, char *value, size_t len, const char *name, const char *lxcpath);
bool (*unfreeze)(void *hdata);
bool (*setup_limits)(void *hdata, struct lxc_conf *conf, bool with_devices);
bool (*chown)(void *hdata, struct lxc_conf *conf);
bool (*attach)(const char *name, const char *lxcpath, pid_t pid);
bool (*mount_cgroup)(void *hdata, const char *root, int type);
int (*nrtasks)(void *hdata);
void (*disconnect)(void);
/* What controllers is the container supposed to use. */
char *cgroup_use;
char *cgroup_pattern;
char *container_cgroup;
/* @hierarchies
* - A NULL-terminated array of struct hierarchy, one per legacy
* hierarchy. No duplicates. First sufficient, writeable mounted
* hierarchy wins.
*/
struct hierarchy **hierarchies;
struct hierarchy *unified;
/*
* @cgroup_layout
* - What cgroup layout the container is running with.
* - CGROUP_LAYOUT_UNKNOWN
* The cgroup layout could not be determined. This should be treated
* as an error condition.
* - CGROUP_LAYOUT_LEGACY
* The container is running with all controllers mounted into legacy
* cgroup hierarchies.
* - CGROUP_LAYOUT_HYBRID
* The container is running with at least one controller mounted
* into a legacy cgroup hierarchy and a mountpoint for the unified
* hierarchy. The unified hierarchy can be empty (no controllers
* enabled) or non-empty (controllers enabled).
* - CGROUP_LAYOUT_UNIFIED
* The container is running on a pure unified cgroup hierarchy. The
* unified hierarchy can be empty (no controllers enabled) or
* non-empty (controllers enabled).
*/
cgroup_layout_t cgroup_layout;
bool (*data_init)(struct cgroup_ops *ops);
void (*destroy)(struct cgroup_ops *ops, struct lxc_handler *handler);
bool (*create)(struct cgroup_ops *ops, struct lxc_handler *handler);
bool (*enter)(struct cgroup_ops *ops, pid_t pid);
const char *(*get_cgroup)(struct cgroup_ops *ops, const char *controller);
bool (*escape)(const struct cgroup_ops *ops);
int (*num_hierarchies)(struct cgroup_ops *ops);
bool (*get_hierarchies)(struct cgroup_ops *ops, int n, char ***out);
int (*set)(struct cgroup_ops *ops, const char *filename,
const char *value, const char *name, const char *lxcpath);
int (*get)(struct cgroup_ops *ops, const char *filename, char *value,
size_t len, const char *name, const char *lxcpath);
bool (*unfreeze)(struct cgroup_ops *ops);
bool (*setup_limits)(struct cgroup_ops *ops, struct lxc_conf *conf,
bool with_devices);
bool (*chown)(struct cgroup_ops *ops, struct lxc_conf *conf);
bool (*attach)(struct cgroup_ops *ops, const char *name,
const char *lxcpath, pid_t pid);
bool (*mount)(struct cgroup_ops *ops, struct lxc_handler *handler,
const char *root, int type);
int (*nrtasks)(struct cgroup_ops *ops);
};
extern bool cgroup_attach(const char *name, const char *lxcpath, pid_t pid);
extern bool cgroup_mount(const char *root, struct lxc_handler *handler, int type);
extern void cgroup_destroy(struct lxc_handler *handler);
extern bool cgroup_init(struct lxc_handler *handler);
extern bool cgroup_create(struct lxc_handler *handler);
extern bool cgroup_setup_limits(struct lxc_handler *handler, bool with_devices);
extern bool cgroup_chown(struct lxc_handler *handler);
extern bool cgroup_enter(struct lxc_handler *handler);
extern void cgroup_cleanup(struct lxc_handler *handler);
extern bool cgroup_create_legacy(struct lxc_handler *handler);
extern int cgroup_nrtasks(struct lxc_handler *handler);
extern const char *cgroup_get_cgroup(struct lxc_handler *handler,
const char *subsystem);
extern bool cgroup_escape();
extern int cgroup_num_hierarchies();
extern bool cgroup_get_hierarchies(int i, char ***out);
extern bool cgroup_unfreeze(struct lxc_handler *handler);
extern void cgroup_disconnect(void);
extern struct cgroup_ops *cgroup_init(struct lxc_handler *handler);
extern void cgroup_exit(struct cgroup_ops *ops);
extern void prune_init_scope(char *cg);
extern bool is_crucial_cgroup_subsystem(const char *s);
......
src/lxc/commands.c
......@@ -473,11 +473,12 @@ static int lxc_cmd_get_cgroup_callback(int fd, struct lxc_cmd_req *req,
{
const char *path;
struct lxc_cmd_rsp rsp;
struct cgroup_ops *cgroup_ops = handler->cgroup_ops;
if (req->datalen > 0)
path = cgroup_get_cgroup(handler, req->data);
path = cgroup_ops->get_cgroup(cgroup_ops, req->data);
else
path = cgroup_get_cgroup(handler, NULL);
path = cgroup_ops->get_cgroup(cgroup_ops, NULL);
if (!path)
return -1;
......@@ -637,6 +638,7 @@ static int lxc_cmd_stop_callback(int fd, struct lxc_cmd_req *req,
{
struct lxc_cmd_rsp rsp;
int stopsignal = SIGKILL;
struct cgroup_ops *cgroup_ops = handler->cgroup_ops;
if (handler->conf->stopsignal)
stopsignal = handler->conf->stopsignal;
......@@ -648,7 +650,7 @@ static int lxc_cmd_stop_callback(int fd, struct lxc_cmd_req *req,
* lxc_unfreeze() would do another cmd (GET_CGROUP) which would
* deadlock us.
*/
if (cgroup_unfreeze(handler))
if (cgroup_ops->unfreeze(cgroup_ops))
return 0;
ERROR("Failed to unfreeze container \"%s\"", handler->name);
......
src/lxc/conf.c
......@@ -757,7 +757,10 @@ static int lxc_mount_auto_mounts(struct lxc_conf *conf, int flags, struct lxc_ha
if (flags & LXC_AUTO_CGROUP_FORCE)
cg_flags |= LXC_AUTO_CGROUP_FORCE;
if (!cgroup_mount(conf->rootfs.path ? conf->rootfs.mount : "", handler, cg_flags)) {
if (!handler->cgroup_ops->mount(handler->cgroup_ops,
handler,
conf->rootfs.path ? conf->rootfs.mount : "",
cg_flags)) {
SYSERROR("Failed to mount \"/sys/fs/cgroup\"");
return -1;
}
......
src/lxc/criu.c
......@@ -171,7 +171,7 @@ static int cmp_version(const char *v1, const char *v2)
return -1;
}
static void exec_criu(struct criu_opts *opts)
static void exec_criu(struct cgroup_ops *cgroup_ops, struct criu_opts *opts)
{
char **argv, log[PATH_MAX];
int static_args = 23, argc = 0, i, ret;
......@@ -190,7 +190,7 @@ static void exec_criu(struct criu_opts *opts)
* /actual/ root cgroup so that lxcfs thinks criu has enough rights to
* see all cgroups.
*/
if (!cgroup_escape()) {
if (!cgroup_ops->escape(cgroup_ops)) {
ERROR("failed to escape cgroups");
return;
}
......@@ -248,8 +248,8 @@ static void exec_criu(struct criu_opts *opts)
return;
}
if (cgroup_num_hierarchies() > 0)
static_args += 2 * cgroup_num_hierarchies();
if (cgroup_ops->num_hierarchies(cgroup_ops) > 0)
static_args += 2 * cgroup_ops->num_hierarchies(cgroup_ops);
if (opts->user->verbose)
static_args++;
......@@ -306,11 +306,11 @@ static void exec_criu(struct criu_opts *opts)
DECLARE_ARG("-o");
DECLARE_ARG(log);
for (i = 0; i < cgroup_num_hierarchies(); i++) {
for (i = 0; i < cgroup_ops->num_hierarchies(cgroup_ops); i++) {
char **controllers = NULL, *fullname;
char *path, *tmp;
if (!cgroup_get_hierarchies(i, &controllers)) {
if (!cgroup_ops->get_hierarchies(cgroup_ops, i, &controllers)) {
ERROR("failed to get hierarchy %d", i);
goto err;
}
......@@ -328,7 +328,7 @@ static void exec_criu(struct criu_opts *opts)
} else {
const char *p;
p = cgroup_get_cgroup(opts->handler, controllers[0]);
p = cgroup_ops->get_cgroup(cgroup_ops, controllers[0]);
if (!p) {
ERROR("failed to get cgroup path for %s", controllers[0]);
goto err;
......@@ -937,6 +937,7 @@ static void do_restore(struct lxc_container *c, int status_pipe, struct migrate_
struct lxc_handler *handler;
int status = 0;
int pipes[2] = {-1, -1};
struct cgroup_ops *cgroup_ops;
/* Try to detach from the current controlling tty if it exists.
* Othwerise, lxc_init (via lxc_console) will attach the container's
......@@ -958,12 +959,12 @@ static void do_restore(struct lxc_container *c, int status_pipe, struct migrate_
if (lxc_init(c->name, handler) < 0)
goto out;
if (!cgroup_init(handler)) {
ERROR("failed initing cgroups");
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
goto out_fini_handler;
}
handler->cgroup_ops = cgroup_ops;
if (!cgroup_create(handler)) {
if (!cgroup_ops->create(cgroup_ops, handler)) {
ERROR("failed creating groups");
goto out_fini_handler;
}
......@@ -1052,7 +1053,7 @@ static void do_restore(struct lxc_container *c, int status_pipe, struct migrate_
os.console_name = c->lxc_conf->console.name;
/* exec_criu() returning is an error */
exec_criu(&os);
exec_criu(cgroup_ops, &os);
umount(rootfs->mount);
rmdir(rootfs->mount);
goto out_fini_handler;
......@@ -1253,16 +1254,21 @@ static bool do_dump(struct lxc_container *c, char *mode, struct migrate_opts *op
if (pid == 0) {
struct criu_opts os;
struct lxc_handler h;
struct cgroup_ops *cgroup_ops;
close(criuout[0]);
lxc_zero_handler(&h);
h.name = c->name;
if (!cgroup_init(&h)) {
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops) {
ERROR("failed to cgroup_init()");
_exit(EXIT_FAILURE);
return -1;
}
h.cgroup_ops = cgroup_ops;
os.pipefd = criuout[1];
os.action = mode;
......@@ -1278,7 +1284,7 @@ static bool do_dump(struct lxc_container *c, char *mode, struct migrate_opts *op
}
/* exec_criu() returning is an error */
exec_criu(&os);
exec_criu(cgroup_ops, &os);
free(criu_version);
_exit(EXIT_FAILURE);
} else {
......
src/lxc/freezer.c
......@@ -31,6 +31,7 @@
#include <sys/types.h>
#include <sys/param.h>
#include "cgroup.h"
#include "commands.h"
#include "error.h"
#include "log.h"
......@@ -45,8 +46,14 @@ lxc_state_t freezer_state(const char *name, const char *lxcpath)
{
int ret;
char v[100];
struct cgroup_ops *cgroup_ops;
ret = lxc_cgroup_get("freezer.state", v, sizeof(v), name, lxcpath);
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
return -1;
ret = cgroup_ops->get(cgroup_ops, "freezer.state", v, sizeof(v), name, lxcpath);
cgroup_exit(cgroup_ops);
if (ret < 0)
return -1;
......@@ -60,19 +67,26 @@ static int do_freeze_thaw(bool freeze, const char *name, const char *lxcpath)
{
int ret;
char v[100];
struct cgroup_ops *cgroup_ops;
const char *state = freeze ? "FROZEN" : "THAWED";
size_t state_len = 6;
lxc_state_t new_state = freeze ? FROZEN : THAWED;
ret = lxc_cgroup_set("freezer.state", state, name, lxcpath);
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
return -1;
ret = cgroup_ops->set(cgroup_ops, "freezer.state", state, name, lxcpath);
if (ret < 0) {
cgroup_exit(cgroup_ops);
ERROR("Failed to freeze %s", name);
return -1;
}
for (;;) {
ret = lxc_cgroup_get("freezer.state", v, sizeof(v), name, lxcpath);
ret = cgroup_ops->get(cgroup_ops, "freezer.state", v, sizeof(v), name, lxcpath);
if (ret < 0) {
cgroup_exit(cgroup_ops);
ERROR("Failed to get freezer state of %s", name);
return -1;
}
......@@ -82,6 +96,7 @@ static int do_freeze_thaw(bool freeze, const char *name, const char *lxcpath)
ret = strncmp(v, state, state_len);
if (ret == 0) {
cgroup_exit(cgroup_ops);
lxc_cmd_serve_state_clients(name, lxcpath, new_state);
lxc_monitor_send_state(name, new_state, lxcpath);
return 0;
......
src/lxc/lxc.h
......@@ -98,29 +98,6 @@ extern int lxc_unfreeze(const char *name, const char *lxcpath);
extern lxc_state_t lxc_state(const char *name, const char *lxcpath);
/*
* Set a specified value for a specified subsystem. The specified
* subsystem must be fully specified, eg. "cpu.shares"
* @filename : the cgroup attribute filename
* @value : the value to be set
* @name : the name of the container
* @lxcpath : lxc config path for container
* Returns 0 on success, < 0 otherwise
*/
extern int lxc_cgroup_set(const char *filename, const char *value, const char *name, const char *lxcpath);
/*
* Get a specified value for a specified subsystem. The specified
* subsystem must be fully specified, eg. "cpu.shares"
* @filename : the cgroup attribute filename
* @value : the value to be set
* @len : the len of the value variable
* @name : the name of the container
* @lxcpath : lxc config path for container
* Returns the number of bytes read, < 0 on error
*/
extern int lxc_cgroup_get(const char *filename, char *value, size_t len, const char *name, const char *lxcpath);
/*
* Create and return a new lxccontainer struct.
*/
extern struct lxc_container *lxc_container_new(const char *name, const char *configpath);
......
src/lxc/lxccontainer.c
......@@ -3141,6 +3141,7 @@ WRAP_API_1(bool, lxcapi_set_config_path, const char *)
static bool do_lxcapi_set_cgroup_item(struct lxc_container *c, const char *subsys, const char *value)
{
int ret;
struct cgroup_ops *cgroup_ops;
if (!c)
return false;
......@@ -3148,12 +3149,19 @@ static bool do_lxcapi_set_cgroup_item(struct lxc_container *c, const char *subsy
if (is_stopped(c))
return false;
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
return false;
if (container_disk_lock(c))
return false;
ret = lxc_cgroup_set(subsys, value, c->name, c->config_path);
ret = cgroup_ops->set(cgroup_ops, subsys, value, c->name, c->config_path);
container_disk_unlock(c);
cgroup_exit(cgroup_ops);
return ret == 0;
}
......@@ -3162,6 +3170,7 @@ WRAP_API_2(bool, lxcapi_set_cgroup_item, const char *, const char *)
static int do_lxcapi_get_cgroup_item(struct lxc_container *c, const char *subsys, char *retv, int inlen)
{
int ret;
struct cgroup_ops *cgroup_ops;
if (!c)
return -1;
......@@ -3169,12 +3178,20 @@ static int do_lxcapi_get_cgroup_item(struct lxc_container *c, const char *subsys
if (is_stopped(c))
return -1;
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
return -1;
if (container_disk_lock(c))
return -1;
ret = lxc_cgroup_get(subsys, retv, inlen, c->name, c->config_path);
ret = cgroup_ops->get(cgroup_ops, subsys, retv, inlen, c->name,
c->config_path);
container_disk_unlock(c);
cgroup_exit(cgroup_ops);
return ret;
}
......
src/lxc/start.c
......@@ -849,6 +849,13 @@ int lxc_init(const char *name, struct lxc_handler *handler)
}
TRACE("Chowned console");
handler->cgroup_ops = cgroup_init(handler);
if (!handler->cgroup_ops) {
ERROR("Failed to initialize cgroup driver");
goto out_restore_sigmask;
}
TRACE("Initialized cgroup driver");
INFO("Container \"%s\" is initialized", name);
return 0;
......@@ -871,6 +878,7 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
struct lxc_list *cur, *next;
char *namespaces[LXC_NS_MAX + 1];
size_t namespace_count = 0;
struct cgroup_ops *cgroup_ops = handler->cgroup_ops;
/* The STOPPING state is there for future cleanup code which can take
* awhile.
......@@ -935,7 +943,8 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
while (namespace_count--)
free(namespaces[namespace_count]);
cgroup_destroy(handler);
cgroup_ops->destroy(cgroup_ops, handler);
cgroup_exit(cgroup_ops);
if (handler->conf->reboot == 0) {
/* For all new state clients simply close the command socket.
......@@ -1506,8 +1515,9 @@ static int lxc_spawn(struct lxc_handler *handler)
struct lxc_list *id_map;
const char *name = handler->name;
const char *lxcpath = handler->lxcpath;
bool cgroups_connected = false, share_ns = false;
bool share_ns = false;
struct lxc_conf *conf = handler->conf;
struct cgroup_ops *cgroup_ops = handler->cgroup_ops;
id_map = &conf->id_map;
wants_to_map_ids = !lxc_list_empty(id_map);
......@@ -1567,14 +1577,7 @@ static int lxc_spawn(struct lxc_handler *handler)
}
}
if (!cgroup_init(handler)) {
ERROR("Failed initializing cgroup support");
goto out_delete_net;
}
cgroups_connected = true;
if (!cgroup_create(handler)) {
if (!cgroup_ops->create(cgroup_ops, handler)) {
ERROR("Failed creating cgroups");
goto out_delete_net;
}
......@@ -1663,15 +1666,15 @@ static int lxc_spawn(struct lxc_handler *handler)
if (ret < 0)
goto out_delete_net;
if (!cgroup_setup_limits(handler, false)) {
if (!cgroup_ops->setup_limits(cgroup_ops, handler->conf, false)) {
ERROR("Failed to setup cgroup limits for container \"%s\"", name);
goto out_delete_net;
}
if (!cgroup_enter(handler))
if (!cgroup_ops->enter(cgroup_ops, handler->pid))
goto out_delete_net;
if (!cgroup_chown(handler))
if (!cgroup_ops->chown(cgroup_ops, handler->conf))
goto out_delete_net;
/* Now we're ready to preserve the network namespace */
......@@ -1736,15 +1739,12 @@ static int lxc_spawn(struct lxc_handler *handler)
if (ret < 0)
goto out_delete_net;
if (!cgroup_setup_limits(handler, true)) {
if (!cgroup_ops->setup_limits(cgroup_ops, handler->conf, true)) {
ERROR("Failed to setup legacy device cgroup controller limits");
goto out_delete_net;
}
TRACE("Set up legacy device cgroup controller limits");
cgroup_disconnect();
cgroups_connected = false;
if (handler->ns_clone_flags & CLONE_NEWCGROUP) {
/* Now we're ready to preserve the cgroup namespace */
ret = lxc_try_preserve_ns(handler->pid, "cgroup");
......@@ -1821,9 +1821,6 @@ static int lxc_spawn(struct lxc_handler *handler)
return 0;
out_delete_net:
if (cgroups_connected)
cgroup_disconnect();
if (handler->ns_clone_flags & CLONE_NEWNET)
lxc_delete_network(handler);
......
src/lxc/start.h
......@@ -132,6 +132,8 @@ struct lxc_handler {
* true.
*/
int exit_status;
struct cgroup_ops *cgroup_ops;
};
struct execute_args {
......
src/tests/cgpath.c
......@@ -53,6 +53,7 @@ static int test_running_container(const char *lxcpath,
char *cgrelpath;
char relpath[PATH_MAX+1];
char value[NAME_MAX], value_save[NAME_MAX];
struct cgroup_ops *cgroup_ops;
sprintf(relpath, "%s/%s", group ? group : "lxc", name);
......@@ -75,36 +76,41 @@ static int test_running_container(const char *lxcpath,
goto err3;
}
cgroup_ops = cgroup_init(NULL);
if (!cgroup_ops)
goto err3;
/* test get/set value using memory.soft_limit_in_bytes file */
ret = lxc_cgroup_get("memory.soft_limit_in_bytes", value, sizeof(value),
c->name, c->config_path);
ret = cgroup_ops->get(cgroup_ops, "memory.soft_limit_in_bytes", value,
sizeof(value), c->name, c->config_path);
if (ret < 0) {
TSTERR("lxc_cgroup_get failed");
TSTERR("cgroup_get failed");
goto err3;
}
strcpy(value_save, value);
ret = lxc_cgroup_set("memory.soft_limit_in_bytes", "512M", c->name, c->config_path);
ret = cgroup_ops->set(cgroup_ops, "memory.soft_limit_in_bytes", "512M",
c->name, c->config_path);
if (ret < 0) {
TSTERR("lxc_cgroup_set failed %d %d", ret, errno);
TSTERR("cgroup_set failed %d %d", ret, errno);
goto err3;
}
ret = lxc_cgroup_get("memory.soft_limit_in_bytes", value, sizeof(value),
c->name, c->config_path);
ret = cgroup_ops->get(cgroup_ops, "memory.soft_limit_in_bytes", value,
sizeof(value), c->name, c->config_path);
if (ret < 0) {
TSTERR("lxc_cgroup_get failed");
TSTERR("cgroup_get failed");
goto err3;
}
if (strcmp(value, "536870912\n")) {
TSTERR("lxc_cgroup_set_bypath failed to set value >%s<", value);
TSTERR("cgroup_set_bypath failed to set value >%s<", value);
goto err3;
}
/* restore original value */
ret = lxc_cgroup_set("memory.soft_limit_in_bytes", value_save,
c->name, c->config_path);
ret = cgroup_ops->set(cgroup_ops, "memory.soft_limit_in_bytes",
value_save, c->name, c->config_path);
if (ret < 0) {
TSTERR("lxc_cgroup_set failed");
TSTERR("cgroup_set failed");
goto err3;
}
......
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