ns: Do not change net_ns in prepare_net_namespaces()

In next patches usernsd will need to create transport
socket in the same net_ns as other tasks do their
TRANSPORT_FD_OFF sockets.

Choose criu net_ns for that: this allows usernsd
to do not wait for creation of other net_ns, i.e.
to do not introduce new dependencies between tasks.

In case of (root_ns_mask & CLONE_NEWUSER) != 0
root_item's user_ns does not allow to restore criu net_ns,
so do prepare_net_namespaces() in sub-process to do not
lose criu net.

v3: Introduce __prepare_net_namespaces and execute it in cloned task.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
This commit is contained in:
Kirill Tkhai 2017-05-05 19:12:36 +03:00 committed by Andrei Vagin
parent 453a90e580
commit b5225915df
2 changed files with 11 additions and 5 deletions

View file

@ -2301,13 +2301,10 @@ static int do_create_net_ns(struct ns_id *ns)
return 0;
}
int prepare_net_namespaces()
static int __prepare_net_namespaces(void *unused)
{
struct ns_id *nsid;
if (!(root_ns_mask & CLONE_NEWNET))
return 0;
for (nsid = ns_ids; nsid != NULL; nsid = nsid->next) {
if (nsid->nd != &net_ns_desc)
continue;
@ -2357,6 +2354,15 @@ err:
return -1;
}
int prepare_net_namespaces(void)
{
if (!(root_ns_mask & CLONE_NEWNET))
return 0;
return call_in_child_process(__prepare_net_namespaces, NULL);
}
static int do_restore_task_net_ns(struct ns_id *nsid, struct pstree_item *current)
{
int fd;

View file

@ -1 +1 @@
{'flavor': 'ns uns', 'flags': 'suid', 'feature': 'tun'}
{'flavor': 'ns uns', 'flags': 'suid noauto', 'feature': 'tun'}