[PATCH 2/2] btrfs: add WARN_ON() to check is space_info op current

[Zhaolei <zhaolei@cn.fujitsu.com>]

From: Zhao Lei <zhaolei@cn.fujitsu.com>

space_info's value calculation is some complex and easy to cause
bug, add WARN_ON() to help debug.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
---
 fs/btrfs/extent-tree.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3e7a4af..8b51eb5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -9471,9 +9471,17 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 
 	spin_lock(&block_group->space_info->lock);
 	list_del_init(&block_group->ro_list);
+
+	WARN_ON(block_group->space_info->total_bytes
+		< block_group->key.offset);
+	WARN_ON(block_group->space_info->bytes_readonly
+		< block_group->key.offset);
+	WARN_ON(block_group->space_info->disk_total
+		< block_group->key.offset * factor);
 	block_group->space_info->total_bytes -= block_group->key.offset;
 	block_group->space_info->bytes_readonly -= block_group->key.offset;
 	block_group->space_info->disk_total -= block_group->key.offset * factor;
+
 	spin_unlock(&block_group->space_info->lock);
 
 	memcpy(&key, &block_group->key, sizeof(key));
-- 
1.8.5.1