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 <ebiederm@xmission.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index 2ff18c9..d31cb62 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -78,6 +78,9 @@
#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
extern void *ns_get_path(struct path *path, struct task_struct *task,
const struct proc_ns_operations *ns_ops);
+typedef struct ns_common *ns_get_path_helper_t(void *);
+extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
+ void *private_data);
extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
const struct proc_ns_operations *ns_ops);