9p: fix bad kconfig cross-dependency

This patch moves transport dynamic registration and matching to the net
module to prevent a bad Kconfig dependency between the net and fs 9p modules.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

3 files changed, 64 insertions, 0 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index d83cc1247f1e..af9199364049 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -30,6 +30,7 @@
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 #include <net/9p/9p.h>
+#include <linux/parser.h>
 #include <net/9p/transport.h>
 #include <net/9p/conn.h>
 #include <net/9p/client.h>
diff --git a/net/9p/mod.c b/net/9p/mod.c
index 4f9e1d2ac257..b8ac0635ad83 100644
--- a/net/9p/mod.c
+++ b/net/9p/mod.c
@@ -27,6 +27,10 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <net/9p/9p.h>
+#include <linux/fs.h>
+#include <linux/parser.h>
+#include <net/9p/transport.h>
+#include <linux/list.h>
 
 #ifdef CONFIG_NET_9P_DEBUG
 unsigned int p9_debug_level = 0;        /* feature-rific global debug level  */
@@ -40,6 +44,64 @@ extern void p9_mux_global_exit(void);
 extern int p9_sysctl_register(void);
 extern void p9_sysctl_unregister(void);
 
+/*
+ * Dynamic Transport Registration Routines
+ *
+ */
+
+static LIST_HEAD(v9fs_trans_list);
+static struct p9_trans_module *v9fs_default_transport;
+
+/**
+ * v9fs_register_trans - register a new transport with 9p
+ * @m - structure describing the transport module and entry points
+ *
+ */
+void v9fs_register_trans(struct p9_trans_module *m)
+{
+        list_add_tail(&m->list, &v9fs_trans_list);
+        if (m->def)
+                v9fs_default_transport = m;
+}
+EXPORT_SYMBOL(v9fs_register_trans);
+
+/**
+ * v9fs_match_trans - match transport versus registered transports
+ * @arg: string identifying transport
+ *
+ */
+struct p9_trans_module *v9fs_match_trans(const substring_t *name)
+{
+        struct list_head *p;
+        struct p9_trans_module *t = NULL;
+
+        list_for_each(p, &v9fs_trans_list) {
+                t = list_entry(p, struct p9_trans_module, list);
+                if (strncmp(t->name, name->from, name->to-name->from) == 0)
+                        break;
+        }
+        return t;
+}
+EXPORT_SYMBOL(v9fs_match_trans);
+
+/**
+ * v9fs_default_trans - returns pointer to default transport
+ *
+ */
+
+struct p9_trans_module *v9fs_default_trans(void)
+{
+        if (v9fs_default_transport)
+                return v9fs_default_transport;
+        else if (!list_empty(&v9fs_trans_list))
+                return list_first_entry(&v9fs_trans_list,
+                                        struct p9_trans_module, list);
+        else
+                return NULL;
+}
+EXPORT_SYMBOL(v9fs_default_trans);
+
+
 /**
  * v9fs_init - Initialize module
  *
diff --git a/net/9p/mux.c b/net/9p/mux.c
index 934e2ea86e2c..f14014793bed 100644
--- a/net/9p/mux.c
+++ b/net/9p/mux.c
@@ -31,6 +31,7 @@
 #include <linux/idr.h>
 #include <linux/mutex.h>
 #include <net/9p/9p.h>
+#include <linux/parser.h>
 #include <net/9p/transport.h>
 #include <net/9p/conn.h>