btrfs: dev add should add its sysfs entry

we would need the device links to be created,
when device is added.
Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/sysfs.c

@@ -625,14 +625,17 @@ int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-static int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info)
+int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *one_device)
 {
 	int error = 0;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *dev;
 
+	if (!fs_info->device_dir_kobj)
 		fs_info->device_dir_kobj = kobject_create_and_add("devices",
 						&fs_info->super_kobj);
+
 	if (!fs_info->device_dir_kobj)
 		return -ENOMEM;
 
@@ -643,6 +646,9 @@ static int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info)
 		if (!dev->bdev)
 			continue;
 
+		if (one_device && one_device != dev)
+			continue;
+
 		disk = dev->bdev->bd_part;
 		disk_kobj = &part_to_dev(disk)->kobj;
 
@@ -686,7 +692,7 @@ int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
 	if (error)
 		goto failure;
 
-	error = btrfs_kobj_add_device(fs_info);
+	error = btrfs_kobj_add_device(fs_info, NULL);
 	if (error)
 		goto failure;
 

fs/btrfs/sysfs.h

@@ -66,6 +66,8 @@ char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags);
 extern const char * const btrfs_feature_set_names[3];
 extern struct kobj_type space_info_ktype;
 extern struct kobj_type btrfs_raid_ktype;
+int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
+		struct btrfs_device *one_device);
 int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
                 struct btrfs_device *one_device);
 #endif /* _BTRFS_SYSFS_H_ */

fs/btrfs/volumes.c

@@ -2147,6 +2147,10 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
 	btrfs_set_super_num_devices(root->fs_info->super_copy,
 				    total_bytes + 1);
+
+	/* add sysfs device entry */
+	btrfs_kobj_add_device(root->fs_info, device);
+
 	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 	if (seeding_dev) {
@@ -2209,6 +2213,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	unlock_chunks(root);
 	btrfs_end_transaction(trans, root);
 	rcu_string_free(device->name);
+	btrfs_kobj_rm_device(root->fs_info, device);
 	kfree(device);
 error:
 	blkdev_put(bdev, FMODE_EXCL);