9p: implement proper trans module refcounting and unregistration
9p trans modules aren't refcounted nor were they unregistered
properly. Fix it.
* Add 9p_trans_module->owner and reference the module on each trans
instance creation and put it on destruction.
* Protect v9fs_trans_list with a spinlock. This isn't strictly
necessary as the list is manipulated only during module loading /
unloading but it's a good idea to make the API safe.
* Unregister trans modules when the corresponding module is being
unloaded.
* While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index b3d3e27..c3626c0 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -596,4 +596,5 @@
int p9_error_init(void);
int p9_errstr2errno(char *, int);
int p9_trans_fd_init(void);
+void p9_trans_fd_exit(void);
#endif /* NET_9P_H */
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 0db3a40..3ca7371 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -26,6 +26,8 @@
#ifndef NET_9P_TRANSPORT_H
#define NET_9P_TRANSPORT_H
+#include <linux/module.h>
+
/**
* enum p9_trans_status - different states of underlying transports
* @Connected: transport is connected and healthy
@@ -91,9 +93,12 @@
int maxsize; /* max message size of transport */
int def; /* this transport should be default */
struct p9_trans * (*create)(const char *, char *, int, unsigned char);
+ struct module *owner;
};
void v9fs_register_trans(struct p9_trans_module *m);
-struct p9_trans_module *v9fs_match_trans(const substring_t *name);
-struct p9_trans_module *v9fs_default_trans(void);
+void v9fs_unregister_trans(struct p9_trans_module *m);
+struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name);
+struct p9_trans_module *v9fs_get_default_trans(void);
+void v9fs_put_trans(struct p9_trans_module *m);
#endif /* NET_9P_TRANSPORT_H */