Actual removal is done under the lock, but for checking if need to bother
the lockless list_empty() is safe - either that namespace never had never
been added to mnt_ns_tree, in which case the list will stay empty, or
whoever had allocated it has called mnt_ns_tree_add() and it has already
run to completion. After that point list_empty() will become false and
will remain false, no matter what we do with the neighbors in mnt_ns_list.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index c324800e770c..daa72292ea58 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -195,7 +195,7 @@ static void mnt_ns_release_rcu(struct rcu_head *rcu)
static void mnt_ns_tree_remove(struct mnt_namespace *ns)
{
/* remove from global mount namespace list */
- if (!is_anon_ns(ns)) {
+ if (!list_empty(&ns->mnt_ns_list)) {
mnt_ns_tree_write_lock();
rb_erase(&ns->mnt_ns_tree_node, &mnt_ns_tree);
list_bidir_del_rcu(&ns->mnt_ns_list);
--
2.47.2
