nsfs: generalize ns_get_path() for path resolution with a task
ns_get_path() takes struct task_struct and proc_ns_ops as its
parameters. For path resolution directly from a namespace,
e.g. based on a networking device's net name space, we need
more flexibility. Add a ns_get_path_cb() helper which will
allow callers to use any method of obtaining the name space
reference. Convert ns_get_path() to use ns_get_path_cb().
Following patches will bring a networking user.
CC: Eric W. Biederman <[email protected]>
Suggested-by: Daniel Borkmann <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 7c6f76d..36b0772 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -103,14 +103,14 @@ static void *__ns_get_path(struct path *path, struct ns_common *ns)
goto got_it;
}
-void *ns_get_path(struct path *path, struct task_struct *task,
- const struct proc_ns_operations *ns_ops)
+void *ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
+ void *private_data)
{
struct ns_common *ns;
void *ret;
again:
- ns = ns_ops->get(task);
+ ns = ns_get_cb(private_data);
if (!ns)
return ERR_PTR(-ENOENT);
@@ -120,6 +120,29 @@ void *ns_get_path(struct path *path, struct task_struct *task,
return ret;
}
+struct ns_get_path_task_args {
+ const struct proc_ns_operations *ns_ops;
+ struct task_struct *task;
+};
+
+static struct ns_common *ns_get_path_task(void *private_data)
+{
+ struct ns_get_path_task_args *args = private_data;
+
+ return args->ns_ops->get(args->task);
+}
+
+void *ns_get_path(struct path *path, struct task_struct *task,
+ const struct proc_ns_operations *ns_ops)
+{
+ struct ns_get_path_task_args args = {
+ .ns_ops = ns_ops,
+ .task = task,
+ };
+
+ return ns_get_path_cb(path, ns_get_path_task, &args);
+}
+
int open_related_ns(struct ns_common *ns,
struct ns_common *(*get_ns)(struct ns_common *ns))
{
