[PATCH 01/10] btrfs: add btrfs_delete_ref_head helper

[Josef Bacik <josef@toxicpanda.com>]

From: Josef Bacik <jbacik@fb.com>

We do this dance in cleanup_ref_head and check_ref_cleanup, unify it
into a helper and cleanup the calling functions.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/delayed-ref.c | 14 ++++++++++++++
 fs/btrfs/delayed-ref.h |  3 ++-
 fs/btrfs/extent-tree.c | 22 +++-------------------
 3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 9301b3ad9217..b3e4c9fcb664 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -400,6 +400,20 @@ struct btrfs_delayed_ref_head *btrfs_select_ref_head(
 	return head;
 }
 
+void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			   struct btrfs_delayed_ref_head *head)
+{
+	lockdep_assert_held(&delayed_refs->lock);
+	lockdep_assert_held(&head->lock);
+
+	rb_erase_cached(&head->href_node, &delayed_refs->href_root);
+	RB_CLEAR_NODE(&head->href_node);
+	atomic_dec(&delayed_refs->num_entries);
+	delayed_refs->num_heads--;
+	if (head->processing == 0)
+		delayed_refs->num_heads_ready--;
+}
+
 /*
  * Helper to insert the ref_node to the tail or merge with tail.
  *
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 8e20c5cb5404..d2af974f68a1 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -261,7 +261,8 @@ static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
 {
 	mutex_unlock(&head->mutex);
 }
-
+void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
+			   struct btrfs_delayed_ref_head *head);
 
 struct btrfs_delayed_ref_head *btrfs_select_ref_head(
 		struct btrfs_delayed_ref_root *delayed_refs);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d242a1174e50..c36b3a42f2bb 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2474,12 +2474,9 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans,
 		spin_unlock(&delayed_refs->lock);
 		return 1;
 	}
-	delayed_refs->num_heads--;
-	rb_erase_cached(&head->href_node, &delayed_refs->href_root);
-	RB_CLEAR_NODE(&head->href_node);
+	btrfs_delete_ref_head(delayed_refs, head);
 	spin_unlock(&head->lock);
 	spin_unlock(&delayed_refs->lock);
-	atomic_dec(&delayed_refs->num_entries);
 
 	trace_run_delayed_ref_head(fs_info, head, 0);
 
@@ -6984,22 +6981,9 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
 	if (!mutex_trylock(&head->mutex))
 		goto out;
 
-	/*
-	 * at this point we have a head with no other entries.  Go
-	 * ahead and process it.
-	 */
-	rb_erase_cached(&head->href_node, &delayed_refs->href_root);
-	RB_CLEAR_NODE(&head->href_node);
-	atomic_dec(&delayed_refs->num_entries);
-
-	/*
-	 * we don't take a ref on the node because we're removing it from the
-	 * tree, so we just steal the ref the tree was holding.
-	 */
-	delayed_refs->num_heads--;
-	if (head->processing == 0)
-		delayed_refs->num_heads_ready--;
+	btrfs_delete_ref_head(delayed_refs, head);
 	head->processing = 0;
+
 	spin_unlock(&head->lock);
 	spin_unlock(&delayed_refs->lock);
 
-- 
2.14.3