btrfs: use rb_entry_safe() where possible to simplify code

Simplify conditionally reading an rb_entry(), there's the
rb_entry_safe() helper that checks the node pointer for NULL so we don't
have to write it explicitly.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 6 insertions, 21 deletions

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 3f1551d8a5c6..c49bf8f2889d 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -454,40 +454,25 @@ static void btrfs_release_delayed_item(struct btrfs_delayed_item *item)
 static struct btrfs_delayed_item *__btrfs_first_delayed_insertion_item(
 					struct btrfs_delayed_node *delayed_node)
 {
-	struct rb_node *p;
-	struct btrfs_delayed_item *item = NULL;
+	struct rb_node *p = rb_first_cached(&delayed_node->ins_root);
 
-	p = rb_first_cached(&delayed_node->ins_root);
-	if (p)
-		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
-
-	return item;
+	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
 }
 
 static struct btrfs_delayed_item *__btrfs_first_delayed_deletion_item(
 					struct btrfs_delayed_node *delayed_node)
 {
-	struct rb_node *p;
-	struct btrfs_delayed_item *item = NULL;
-
-	p = rb_first_cached(&delayed_node->del_root);
-	if (p)
-		item = rb_entry(p, struct btrfs_delayed_item, rb_node);
+	struct rb_node *p = rb_first_cached(&delayed_node->del_root);
 
-	return item;
+	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
 }
 
 static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 						struct btrfs_delayed_item *item)
 {
-	struct rb_node *p;
-	struct btrfs_delayed_item *next = NULL;
-
-	p = rb_next(&item->rb_node);
-	if (p)
-		next = rb_entry(p, struct btrfs_delayed_item, rb_node);
+	struct rb_node *p = rb_next(&item->rb_node);
 
-	return next;
+	return rb_entry_safe(p, struct btrfs_delayed_item, rb_node);
 }
 
 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,