btrfs: add WARN_ON() to check is space_info op current

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

Changelog v1->v2:
 Put WARN_ON()s under the ENOSPC_DEBUG mount option.
 Suggested by: David Sterba <dsterba@suse.cz>

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7a14a4aa50a70571c58f895b5606f9641d671cd1..be4a79a69ed12ce7ec6a1136ac21ce583d979772 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -9732,9 +9732,19 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 
        spin_lock(&block_group->space_info->lock);
        list_del_init(&block_group->ro_list);
+
+       if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
+               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));