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/net/9p/client.c b/net/9p/client.c
index 2ffe40c..10e3203 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -75,7 +75,6 @@
int option;
int ret = 0;
- clnt->trans_mod = v9fs_default_trans();
clnt->dotu = 1;
clnt->msize = 8192;
@@ -108,7 +107,7 @@
clnt->msize = option;
break;
case Opt_trans:
- clnt->trans_mod = v9fs_match_trans(&args[0]);
+ clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
break;
case Opt_legacy:
clnt->dotu = 0;
@@ -117,6 +116,10 @@
continue;
}
}
+
+ if (!clnt->trans_mod)
+ clnt->trans_mod = v9fs_get_default_trans();
+
kfree(options);
return ret;
}
@@ -150,6 +153,7 @@
if (!clnt)
return ERR_PTR(-ENOMEM);
+ clnt->trans_mod = NULL;
clnt->trans = NULL;
spin_lock_init(&clnt->lock);
INIT_LIST_HEAD(&clnt->fidlist);
@@ -235,6 +239,8 @@
clnt->trans = NULL;
}
+ v9fs_put_trans(clnt->trans_mod);
+
list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
p9_fid_destroy(fid);
