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authorAndrey Vagin <avagin@openvz.org>2016-09-06 00:47:15 -0700
committerEric W. Biederman <ebiederm@xmission.com>2016-09-22 19:59:41 -0500
commita7306ed8d94af729ecef8b6e37506a1c6fc14788 (patch)
tree0d45320911d2a339bc0abd6bacd5703c7308c08c /kernel
parent6786741dbf99e44fb0c0ed85a37582b8a26f1c3b (diff)
nsfs: add ioctl to get a parent namespace
Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships. In a future we will use this interface to dump and restore nested namespaces. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/pid_namespace.c19
-rw-r--r--kernel/user_namespace.c1
2 files changed, 20 insertions, 0 deletions
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index c02d744225e1..4fa2d56a936c 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -388,6 +388,24 @@ static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns)
return 0;
}
+static struct ns_common *pidns_get_parent(struct ns_common *ns)
+{
+ struct pid_namespace *active = task_active_pid_ns(current);
+ struct pid_namespace *pid_ns, *p;
+
+ /* See if the parent is in the current namespace */
+ pid_ns = p = to_pid_ns(ns)->parent;
+ for (;;) {
+ if (!p)
+ return ERR_PTR(-EPERM);
+ if (p == active)
+ break;
+ p = p->parent;
+ }
+
+ return &get_pid_ns(pid_ns)->ns;
+}
+
static struct user_namespace *pidns_owner(struct ns_common *ns)
{
return to_pid_ns(ns)->user_ns;
@@ -400,6 +418,7 @@ const struct proc_ns_operations pidns_operations = {
.put = pidns_put,
.install = pidns_install,
.owner = pidns_owner,
+ .get_parent = pidns_get_parent,
};
static __init int pid_namespaces_init(void)
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 0ef683a03c20..a58a219b99c6 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -1034,6 +1034,7 @@ const struct proc_ns_operations userns_operations = {
.put = userns_put,
.install = userns_install,
.owner = userns_owner,
+ .get_parent = ns_get_owner,
};
static __init int user_namespaces_init(void)