block: Replace all ktype default_attrs with groups

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace all of the ktype default_attrs fields in
the block subsystem with default_groups and use the ATTRIBUTE_GROUPS
macro to create the default groups.

Remove default_ctx_attrs[] because it doesn't contain any attributes.

This patch was tested by verifying that the sysfs files for the
attributes in the default groups were created.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 3f9c3f4..5315e53 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -173,10 +173,6 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 	return ret;
 }
 
-static struct attribute *default_ctx_attrs[] = {
-	NULL,
-};
-
 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
 	.attr = {.name = "nr_tags", .mode = 0444 },
 	.show = blk_mq_hw_sysfs_nr_tags_show,
@@ -196,6 +192,7 @@ static struct attribute *default_hw_ctx_attrs[] = {
 	&blk_mq_hw_sysfs_cpus.attr,
 	NULL,
 };
+ATTRIBUTE_GROUPS(default_hw_ctx);
 
 static const struct sysfs_ops blk_mq_sysfs_ops = {
 	.show	= blk_mq_sysfs_show,
@@ -214,13 +211,12 @@ static struct kobj_type blk_mq_ktype = {
 
 static struct kobj_type blk_mq_ctx_ktype = {
 	.sysfs_ops	= &blk_mq_sysfs_ops,
-	.default_attrs	= default_ctx_attrs,
 	.release	= blk_mq_ctx_sysfs_release,
 };
 
 static struct kobj_type blk_mq_hw_ktype = {
 	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
-	.default_attrs	= default_hw_ctx_attrs,
+	.default_groups = default_hw_ctx_groups,
 	.release	= blk_mq_hw_sysfs_release,
 };