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>
This commit is contained in:
Tejun Heo
2008-09-24 16:22:23 -05:00
committed by Eric Van Hensbergen
parent 72d31053f6
commit 72029fe85d
6 changed files with 95 additions and 30 deletions

View File

@ -596,4 +596,5 @@ int p9_idpool_check(int id, struct p9_idpool *p);
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 */

View File

@ -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 @@ struct p9_trans_module {
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 */