btrfs: take an fs_info directly when the root is not used otherwise

There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer.  Let's convert those to
just accept an fs_info pointer directly.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index eb389b1..135bb79 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1509,8 +1509,7 @@ int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
 	record->old_roots = NULL;
 
 	spin_lock(&delayed_refs->lock);
-	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs,
-						      record);
+	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
 	spin_unlock(&delayed_refs->lock);
 	if (ret > 0)
 		kfree(record);
@@ -1518,10 +1517,9 @@ int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
 }
 
 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root,
+				  struct btrfs_fs_info *fs_info,
 				  struct extent_buffer *eb)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	int nr = btrfs_header_nritems(eb);
 	int i, extent_type, ret;
 	struct btrfs_key key;
@@ -1645,7 +1643,7 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 	}
 
 	if (root_level == 0) {
-		ret = btrfs_qgroup_trace_leaf_items(trans, root, root_eb);
+		ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
 		goto out;
 	}
 
@@ -1683,7 +1681,7 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
 
-			eb = read_tree_block(root, child_bytenr, child_gen);
+			eb = read_tree_block(fs_info, child_bytenr, child_gen);
 			if (IS_ERR(eb)) {
 				ret = PTR_ERR(eb);
 				goto out;
@@ -1709,8 +1707,8 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 		}
 
 		if (level == 0) {
-			ret = btrfs_qgroup_trace_leaf_items(trans, root,
-					path->nodes[level]);
+			ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
+							   path->nodes[level]);
 			if (ret)
 				goto out;