[PATCH 5/6] btrfs: add helper to get delayed item root

[Zach Brown <zab@redhat.com>]

This just moves some duplicated code into a helper.  I couldn't bring
myself to add another copy in an upcoming patch.

The delayed_root BUG() in __btrfs_remove_delayed_item() wasn't needed.
The pointer deref will oops later if its null.

And now the remaining BUG() is in one place! :)

Signed-off-by: Zach Brown <zab@redhat.com>
---
 fs/btrfs/delayed-inode.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 67e0f9f..fcce951 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -382,6 +382,16 @@ static struct btrfs_delayed_item *__btrfs_lookup_delayed_insertion_item(
 	return item;
 }
 
+static struct rb_root *get_ins_del_root(struct btrfs_delayed_node *delayed_node,
+					int ins_del)
+{
+	if (ins_del == BTRFS_DELAYED_INSERTION_ITEM)
+		return &delayed_node->ins_root;
+	if (ins_del == BTRFS_DELAYED_DELETION_ITEM)
+		return &delayed_node->del_root;
+	BUG();
+}
+
 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 				    struct btrfs_delayed_item *ins,
 				    int action)
@@ -392,12 +402,7 @@ static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,
 	struct btrfs_delayed_item *item;
 	int cmp;
 
-	if (action == BTRFS_DELAYED_INSERTION_ITEM)
-		root = &delayed_node->ins_root;
-	else if (action == BTRFS_DELAYED_DELETION_ITEM)
-		root = &delayed_node->del_root;
-	else
-		BUG();
+	root = get_ins_del_root(delayed_node, action);
 	p = &root->rb_node;
 	node = &ins->rb_node;
 
@@ -460,15 +465,8 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 
 	delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
 
-	BUG_ON(!delayed_root);
-	BUG_ON(delayed_item->ins_or_del != BTRFS_DELAYED_DELETION_ITEM &&
-	       delayed_item->ins_or_del != BTRFS_DELAYED_INSERTION_ITEM);
-
-	if (delayed_item->ins_or_del == BTRFS_DELAYED_INSERTION_ITEM)
-		root = &delayed_item->delayed_node->ins_root;
-	else
-		root = &delayed_item->delayed_node->del_root;
-
+	root = get_ins_del_root(delayed_item->delayed_node,
+				delayed_item->ins_or_del);
 	rb_erase(&delayed_item->rb_node, root);
 	delayed_item->delayed_node->count--;
 
-- 
1.7.11.7