[PATCH] net/9p: autoload transport modules

Thomas Weißschuh
2021-10-17T13:46:33Z

Automatically load transport modules based on the trans= parameter
passed to mount.
The removes the requirement for the user to know which module to use.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
include/net/9p/transport.h | 6 ++++++
net/9p/mod.c | 30 ++++++++++++++++++++++++------
net/9p/trans_rdma.c | 1 +
net/9p/trans_virtio.c | 1 +
net/9p/trans_xen.c | 1 +
5 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 3eb4261b2958..581555d88cba 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -11,6 +11,8 @@
#ifndef NET_9P_TRANSPORT_H
#define NET_9P_TRANSPORT_H

+#include <linux/module.h>
+
#define P9_DEF_MIN_RESVPORT (665U)
#define P9_DEF_MAX_RESVPORT (1023U)

@@ -55,4 +57,8 @@ void v9fs_unregister_trans(struct p9_trans_module *m);
struct p9_trans_module *v9fs_get_trans_by_name(char *s);
struct p9_trans_module *v9fs_get_default_trans(void);
void v9fs_put_trans(struct p9_trans_module *m);
+
+#define MODULE_ALIAS_9P(transport) \
+ MODULE_ALIAS("9p-" transport)
+
#endif /* NET_9P_TRANSPORT_H */
diff --git a/net/9p/mod.c b/net/9p/mod.c
index 5126566850bd..aa38b8b0e0f6 100644
--- a/net/9p/mod.c
+++ b/net/9p/mod.c
@@ -12,6 +12,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
+#include <linux/kmod.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/moduleparam.h>
@@ -87,12 +88,7 @@ void v9fs_unregister_trans(struct p9_trans_module *m)
}
EXPORT_SYMBOL(v9fs_unregister_trans);

-/**
- * v9fs_get_trans_by_name - get transport with the matching name
- * @s: string identifying transport
- *
- */
-struct p9_trans_module *v9fs_get_trans_by_name(char *s)
+static struct p9_trans_module *_p9_get_trans_by_name(char *s)
{
struct p9_trans_module *t, *found = NULL;

@@ -106,6 +102,28 @@ struct p9_trans_module *v9fs_get_trans_by_name(char *s)
}

spin_unlock(&v9fs_trans_lock);
+
+ return found;
+}
+
+/**
+ * v9fs_get_trans_by_name - get transport with the matching name
+ * @s: string identifying transport
+ *
+ */
+struct p9_trans_module *v9fs_get_trans_by_name(char *s)
+{
+ struct p9_trans_module *found = NULL;
+
+ found = _p9_get_trans_by_name(s);
+
+#ifdef CONFIG_MODULES
+ if (!found) {
+ request_module("9p-%s", s);
+ found = _p9_get_trans_by_name(s);
+ }
+#endif
+
return found;
}
EXPORT_SYMBOL(v9fs_get_trans_by_name);
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index af0a8a6cd3fd..480fd27760d7 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -767,6 +767,7 @@ static void __exit p9_trans_rdma_exit(void)

module_init(p9_trans_rdma_init);
module_exit(p9_trans_rdma_exit);
+MODULE_ALIAS_9P("rdma");

MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
MODULE_DESCRIPTION("RDMA Transport for 9P");
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 490a4c900339..bd5a89c4960d 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -794,6 +794,7 @@ static void __exit p9_virtio_cleanup(void)

module_init(p9_virtio_init);
module_exit(p9_virtio_cleanup);
+MODULE_ALIAS_9P("virtio");

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 3ec1a51a6944..e264dcee019a 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -552,6 +552,7 @@ static int p9_trans_xen_init(void)
return rc;
}
module_init(p9_trans_xen_init);
+MODULE_ALIAS_9P("xen");

static void p9_trans_xen_exit(void)
{

base-commit: fac3cb82a54a4b7c49c932f96ef196cf5774344c
--
2.33.1