Support the generic namespace iterator and lookup infrastructure to support file handles for namespaces.
Signed-off-by: Christian Brauner brauner@kernel.org --- kernel/user_namespace.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 98f4fe84d039..ade5b6806c5c 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -21,6 +21,7 @@ #include <linux/fs_struct.h> #include <linux/bsearch.h> #include <linux/sort.h> +#include <linux/nstree.h>
static struct kmem_cache *user_ns_cachep __ro_after_init; static DEFINE_MUTEX(userns_state_mutex); @@ -158,6 +159,7 @@ int create_user_ns(struct cred *new) goto fail_keyring;
set_cred_user_ns(new, ns); + ns_tree_add(ns); return 0; fail_keyring: #ifdef CONFIG_PERSISTENT_KEYRINGS @@ -200,6 +202,7 @@ static void free_user_ns(struct work_struct *work) do { struct ucounts *ucounts = ns->ucounts; parent = ns->parent; + ns_tree_remove(ns); if (ns->gid_map.nr_extents > UID_GID_MAP_MAX_BASE_EXTENTS) { kfree(ns->gid_map.forward); kfree(ns->gid_map.reverse); @@ -218,7 +221,8 @@ static void free_user_ns(struct work_struct *work) retire_userns_sysctls(ns); key_free_user_ns(ns); ns_free_inum(&ns->ns); - kmem_cache_free(user_ns_cachep, ns); + /* Concurrent nstree traversal depends on a grace period. */ + kfree_rcu(ns, ns.ns_rcu); dec_user_namespaces(ucounts); ns = parent; } while (refcount_dec_and_test(&parent->ns.count)); @@ -1412,6 +1416,7 @@ const struct proc_ns_operations userns_operations = { static __init int user_namespaces_init(void) { user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC | SLAB_ACCOUNT); + ns_tree_add(&init_user_ns); return 0; } subsys_initcall(user_namespaces_init);