1 files changed, 12 insertions, 0 deletions

diff --git a/block/genhd.c b/block/genhd.c
index b922d4801c87..9074f384b097 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -189,6 +189,7 @@ void add_disk(struct gendisk *disk)
                             disk->minors, NULL, exact_match, exact_lock, disk);
         register_disk(disk);
         blk_register_queue(disk);
+        blk_register_filter(disk);
 
         bdi = &disk->queue->backing_dev_info;
         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
@@ -200,6 +201,7 @@ EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
 
 void unlink_gendisk(struct gendisk *disk)
 {
+        blk_unregister_filter(disk);
         sysfs_remove_link(&disk->dev.kobj, "bdi");
         bdi_unregister(&disk->queue->backing_dev_info);
         blk_unregister_queue(disk);
@@ -400,6 +402,14 @@ static ssize_t disk_removable_show(struct device *dev,
                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 }
 
+static ssize_t disk_ro_show(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+
+        return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
+}
+
 static ssize_t disk_size_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
 {
@@ -472,6 +482,7 @@ static ssize_t disk_fail_store(struct device *dev,
 
 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
+static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
@@ -483,6 +494,7 @@ static struct device_attribute dev_attr_fail =
 static struct attribute *disk_attrs[] = {
         &dev_attr_range.attr,
         &dev_attr_removable.attr,
+        &dev_attr_ro.attr,
         &dev_attr_size.attr,
         &dev_attr_capability.attr,
         &dev_attr_stat.attr,