configfs: switch ->default groups to a linked list

Replace the current NULL-terminated array of default groups with a linked
list.  This gets rid of lots of nasty code to size and/or dynamically
allocate the array.

While we're at it also provide a conveniant helper to remove the default
groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org>		[drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>

1 files changed, 79 insertions, 119 deletions

diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index ad8c9b05572d..66753ba7a42e 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -272,11 +272,6 @@ static struct config_item_type uvcg_default_processing_type = {
 
 /* struct uvcg_processing {}; */
 
-static struct config_group *uvcg_processing_default_groups[] = {
-	&uvcg_default_processing.group,
-	NULL,
-};
-
 /* control/processing */
 static struct uvcg_processing_grp {
 	struct config_group	group;
@@ -394,11 +389,6 @@ static struct config_item_type uvcg_default_camera_type = {
 
 /* struct uvcg_camera {}; */
 
-static struct config_group *uvcg_camera_default_groups[] = {
-	&uvcg_default_camera.group,
-	NULL,
-};
-
 /* control/terminal/camera */
 static struct uvcg_camera_grp {
 	struct config_group	group;
@@ -477,11 +467,6 @@ static struct config_item_type uvcg_default_output_type = {
 
 /* struct uvcg_output {}; */
 
-static struct config_group *uvcg_output_default_groups[] = {
-	&uvcg_default_output.group,
-	NULL,
-};
-
 /* control/terminal/output */
 static struct uvcg_output_grp {
 	struct config_group	group;
@@ -491,12 +476,6 @@ static struct config_item_type uvcg_output_grp_type = {
 	.ct_owner = THIS_MODULE,
 };
 
-static struct config_group *uvcg_terminal_default_groups[] = {
-	&uvcg_camera_grp.group,
-	&uvcg_output_grp.group,
-	NULL,
-};
-
 /* control/terminal */
 static struct uvcg_terminal_grp {
 	struct config_group	group;
@@ -619,12 +598,6 @@ static struct config_item_type uvcg_control_class_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
-static struct config_group *uvcg_control_class_default_groups[] = {
-	&uvcg_control_class_fs.group,
-	&uvcg_control_class_ss.group,
-	NULL,
-};
-
 /* control/class */
 static struct uvcg_control_class_grp {
 	struct config_group	group;
@@ -634,14 +607,6 @@ static struct config_item_type uvcg_control_class_grp_type = {
 	.ct_owner = THIS_MODULE,
 };
 
-static struct config_group *uvcg_control_default_groups[] = {
-	&uvcg_control_header_grp.group,
-	&uvcg_processing_grp.group,
-	&uvcg_terminal_grp.group,
-	&uvcg_control_class_grp.group,
-	NULL,
-};
-
 /* control */
 static struct uvcg_control_grp {
 	struct config_group	group;
@@ -1780,11 +1745,6 @@ static struct config_item_type uvcg_default_color_matching_type = {
 
 /* struct uvcg_color_matching {}; */
 
-static struct config_group *uvcg_color_matching_default_groups[] = {
-	&uvcg_default_color_matching.group,
-	NULL,
-};
-
 /* streaming/color_matching */
 static struct uvcg_color_matching_grp {
 	struct config_group	group;
@@ -2145,13 +2105,6 @@ static struct config_item_type uvcg_streaming_class_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
-static struct config_group *uvcg_streaming_class_default_groups[] = {
-	&uvcg_streaming_class_fs.group,
-	&uvcg_streaming_class_hs.group,
-	&uvcg_streaming_class_ss.group,
-	NULL,
-};
-
 /* streaming/class */
 static struct uvcg_streaming_class_grp {
 	struct config_group	group;
@@ -2161,15 +2114,6 @@ static struct config_item_type uvcg_streaming_class_grp_type = {
 	.ct_owner = THIS_MODULE,
 };
 
-static struct config_group *uvcg_streaming_default_groups[] = {
-	&uvcg_streaming_header_grp.group,
-	&uvcg_uncompressed_grp.group,
-	&uvcg_mjpeg_grp.group,
-	&uvcg_color_matching_grp.group,
-	&uvcg_streaming_class_grp.group,
-	NULL,
-};
-
 /* streaming */
 static struct uvcg_streaming_grp {
 	struct config_group	group;
@@ -2179,12 +2123,6 @@ static struct config_item_type uvcg_streaming_grp_type = {
 	.ct_owner = THIS_MODULE,
 };
 
-static struct config_group *uvcg_default_groups[] = {
-	&uvcg_control_grp.group,
-	&uvcg_streaming_grp.group,
-	NULL,
-};
-
 static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
 {
 	return container_of(to_config_group(item), struct f_uvc_opts,
@@ -2273,59 +2211,64 @@ static struct config_item_type uvc_func_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
-static inline void uvcg_init_group(struct config_group *g,
-				   struct config_group **default_groups,
-				   const char *name,
-				   struct config_item_type *type)
-{
-	g->default_groups = default_groups;
-	config_group_init_type_name(g, name, type);
-}
-
 int uvcg_attach_configfs(struct f_uvc_opts *opts)
 {
 	config_group_init_type_name(&uvcg_control_header_grp.group,
 				    "header",
 				    &uvcg_control_header_grp_type);
+
 	config_group_init_type_name(&uvcg_default_processing.group,
-				    "default",
-				    &uvcg_default_processing_type);
-	uvcg_init_group(&uvcg_processing_grp.group,
-			uvcg_processing_default_groups,
-			"processing",
-			&uvcg_processing_grp_type);
+			"default", &uvcg_default_processing_type);
+	config_group_init_type_name(&uvcg_processing_grp.group,
+			"processing", &uvcg_processing_grp_type);
+	configfs_add_default_group(&uvcg_default_processing.group,
+			&uvcg_processing_grp.group);
+
 	config_group_init_type_name(&uvcg_default_camera.group,
-				    "default",
-				    &uvcg_default_camera_type);
-	uvcg_init_group(&uvcg_camera_grp.group,
-			uvcg_camera_default_groups,
-			"camera",
-			&uvcg_camera_grp_type);
+			"default", &uvcg_default_camera_type);
+	config_group_init_type_name(&uvcg_camera_grp.group,
+			"camera", &uvcg_camera_grp_type);
+	configfs_add_default_group(&uvcg_default_camera.group,
+			&uvcg_camera_grp.group);
+
 	config_group_init_type_name(&uvcg_default_output.group,
-				    "default",
-				    &uvcg_default_output_type);
-	uvcg_init_group(&uvcg_output_grp.group,
-			uvcg_output_default_groups,
-			"output",
-			&uvcg_output_grp_type);
-	uvcg_init_group(&uvcg_terminal_grp.group,
-			uvcg_terminal_default_groups,
-			"terminal",
-			&uvcg_terminal_grp_type);
+			"default", &uvcg_default_output_type);
+	config_group_init_type_name(&uvcg_output_grp.group,
+			"output", &uvcg_output_grp_type);
+	configfs_add_default_group(&uvcg_default_output.group,
+			&uvcg_output_grp.group);
+
+	config_group_init_type_name(&uvcg_terminal_grp.group,
+			"terminal", &uvcg_terminal_grp_type);
+	configfs_add_default_group(&uvcg_camera_grp.group,
+			&uvcg_terminal_grp.group);
+	configfs_add_default_group(&uvcg_output_grp.group,
+			&uvcg_terminal_grp.group);
+
 	config_group_init_type_name(&uvcg_control_class_fs.group,
-				    "fs",
-				    &uvcg_control_class_type);
+			"fs", &uvcg_control_class_type);
 	config_group_init_type_name(&uvcg_control_class_ss.group,
-				    "ss",
-				    &uvcg_control_class_type);
-	uvcg_init_group(&uvcg_control_class_grp.group,
-			uvcg_control_class_default_groups,
+			"ss", &uvcg_control_class_type);
+	config_group_init_type_name(&uvcg_control_class_grp.group,
 			"class",
 			&uvcg_control_class_grp_type);
-	uvcg_init_group(&uvcg_control_grp.group,
-			uvcg_control_default_groups,
+	configfs_add_default_group(&uvcg_control_class_fs.group,
+			&uvcg_control_class_grp.group);
+	configfs_add_default_group(&uvcg_control_class_ss.group,
+			&uvcg_control_class_grp.group);
+
+	config_group_init_type_name(&uvcg_control_grp.group,
 			"control",
 			&uvcg_control_grp_type);
+	configfs_add_default_group(&uvcg_control_header_grp.group,
+			&uvcg_control_grp.group);
+	configfs_add_default_group(&uvcg_processing_grp.group,
+			&uvcg_control_grp.group);
+	configfs_add_default_group(&uvcg_terminal_grp.group,
+			&uvcg_control_grp.group);
+	configfs_add_default_group(&uvcg_control_class_grp.group,
+			&uvcg_control_grp.group);
+
 	config_group_init_type_name(&uvcg_streaming_header_grp.group,
 				    "header",
 				    &uvcg_streaming_header_grp_type);
@@ -2338,30 +2281,47 @@ int uvcg_attach_configfs(struct f_uvc_opts *opts)
 	config_group_init_type_name(&uvcg_default_color_matching.group,
 				    "default",
 				    &uvcg_default_color_matching_type);
-	uvcg_init_group(&uvcg_color_matching_grp.group,
-			uvcg_color_matching_default_groups,
+	config_group_init_type_name(&uvcg_color_matching_grp.group,
 			"color_matching",
 			&uvcg_color_matching_grp_type);
+	configfs_add_default_group(&uvcg_default_color_matching.group,
+			&uvcg_color_matching_grp.group);
+
 	config_group_init_type_name(&uvcg_streaming_class_fs.group,
-				    "fs",
-				    &uvcg_streaming_class_type);
+			"fs", &uvcg_streaming_class_type);
 	config_group_init_type_name(&uvcg_streaming_class_hs.group,
-				    "hs",
-				    &uvcg_streaming_class_type);
+			"hs", &uvcg_streaming_class_type);
 	config_group_init_type_name(&uvcg_streaming_class_ss.group,
-				    "ss",
-				    &uvcg_streaming_class_type);
-	uvcg_init_group(&uvcg_streaming_class_grp.group,
-			uvcg_streaming_class_default_groups,
-			"class",
-			&uvcg_streaming_class_grp_type);
-	uvcg_init_group(&uvcg_streaming_grp.group,
-			uvcg_streaming_default_groups,
-			"streaming",
-			&uvcg_streaming_grp_type);
-	uvcg_init_group(&opts->func_inst.group,
-			uvcg_default_groups,
+			"ss", &uvcg_streaming_class_type);
+	config_group_init_type_name(&uvcg_streaming_class_grp.group,
+			"class", &uvcg_streaming_class_grp_type);
+	configfs_add_default_group(&uvcg_streaming_class_fs.group,
+			&uvcg_streaming_class_grp.group);
+	configfs_add_default_group(&uvcg_streaming_class_hs.group,
+			&uvcg_streaming_class_grp.group);
+	configfs_add_default_group(&uvcg_streaming_class_ss.group,
+			&uvcg_streaming_class_grp.group);
+
+	config_group_init_type_name(&uvcg_streaming_grp.group,
+			"streaming", &uvcg_streaming_grp_type);
+	configfs_add_default_group(&uvcg_streaming_header_grp.group,
+			&uvcg_streaming_grp.group);
+	configfs_add_default_group(&uvcg_uncompressed_grp.group,
+			&uvcg_streaming_grp.group);
+	configfs_add_default_group(&uvcg_mjpeg_grp.group,
+			&uvcg_streaming_grp.group);
+	configfs_add_default_group(&uvcg_color_matching_grp.group,
+			&uvcg_streaming_grp.group);
+	configfs_add_default_group(&uvcg_streaming_class_grp.group,
+			&uvcg_streaming_grp.group);
+
+	config_group_init_type_name(&opts->func_inst.group,
 			"",
 			&uvc_func_type);
+	configfs_add_default_group(&uvcg_control_grp.group,
+			&opts->func_inst.group);
+	configfs_add_default_group(&uvcg_streaming_grp.group,
+			&opts->func_inst.group);
+
 	return 0;
 }