set non device cgroup items before the cgroup is entered

This allows some special cgroup items such as memory.kmem.limit_in_bytes
to be successfully set, since they must be set before any task is put
into the cgroup.

The devices cgroup is setup later giving the container a chance to mount
file systems before the device it might want to mount from becomes
unavailable.

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
This commit is contained in:
Dwight Engen 2013-05-15 12:27:34 -04:00 committed by Serge Hallyn
parent d9e80daf54
commit 6031a6e5f9
3 changed files with 27 additions and 11 deletions

View File

@ -1401,7 +1401,8 @@ static int setup_kmsg(const struct lxc_rootfs *rootfs,
return 0;
}
int setup_cgroup(const char *cgpath, struct lxc_list *cgroups)
static int _setup_cgroup(const char *cgpath, struct lxc_list *cgroups,
int devices)
{
struct lxc_list *iterator;
struct lxc_cgroup *cg;
@ -1411,13 +1412,15 @@ int setup_cgroup(const char *cgpath, struct lxc_list *cgroups)
return 0;
lxc_list_for_each(iterator, cgroups) {
cg = iterator->elem;
if (lxc_cgroup_set_bypath(cgpath, cg->subsystem, cg->value)) {
ERROR("Error setting %s to %s for %s\n", cg->subsystem,
cg->value, cgpath);
goto out;
if (devices == !strncmp("devices", cg->subsystem, 7)) {
if (lxc_cgroup_set_bypath(cgpath, cg->subsystem,
cg->value)) {
ERROR("Error setting %s to %s for %s\n",
cg->subsystem, cg->value, cgpath);
goto out;
}
}
DEBUG("cgroup '%s' set to '%s'", cg->subsystem, cg->value);
@ -1429,6 +1432,16 @@ out:
return ret;
}
int setup_cgroup_devices(const char *cgpath, struct lxc_list *cgroups)
{
return _setup_cgroup(cgpath, cgroups, 1);
}
int setup_cgroup(const char *cgpath, struct lxc_list *cgroups)
{
return _setup_cgroup(cgpath, cgroups, 0);
}
static void parse_mntopt(char *opt, unsigned long *flags, char **data)
{
struct mount_opt *mo;

View File

@ -287,6 +287,7 @@ struct lxc_conf {
int run_lxc_hooks(const char *name, char *hook, struct lxc_conf *conf);
extern int setup_cgroup(const char *cgpath, struct lxc_list *cgroups);
extern int setup_cgroup_devices(const char *cgpath, struct lxc_list *cgroups);
extern int detect_shared_rootfs(void);
/*
@ -313,8 +314,6 @@ extern int lxc_clear_cgroups(struct lxc_conf *c, const char *key);
extern int lxc_clear_mount_entries(struct lxc_conf *c);
extern int lxc_clear_hooks(struct lxc_conf *c, const char *key);
extern int setup_cgroup(const char *name, struct lxc_list *cgroups);
extern int uid_shift_ttys(int pid, struct lxc_conf *conf);
/*

View File

@ -809,6 +809,11 @@ int lxc_spawn(struct lxc_handler *handler)
if ((handler->cgroup = lxc_cgroup_path_create(NULL, name)) == NULL)
goto out_delete_net;
if (setup_cgroup(handler->cgroup, &handler->conf->cgroup)) {
ERROR("failed to setup the cgroups for '%s'", name);
goto out_delete_net;
}
if (lxc_cgroup_enter(handler->cgroup, handler->pid) < 0)
goto out_delete_net;
@ -839,12 +844,11 @@ int lxc_spawn(struct lxc_handler *handler)
if (lxc_sync_barrier_child(handler, LXC_SYNC_POST_CONFIGURE))
goto out_delete_net;
if (setup_cgroup(handler->cgroup, &handler->conf->cgroup)) {
ERROR("failed to setup the cgroups for '%s'", name);
if (setup_cgroup_devices(handler->cgroup, &handler->conf->cgroup)) {
ERROR("failed to setup the devices cgroup for '%s'", name);
goto out_delete_net;
}
/* Tell the child to complete its initialization and wait for
* it to exec or return an error. (the child will never
* return LXC_SYNC_POST_CGROUP+1. It will either close the