Commit 5473aeed authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: move select_delayed_ref() and export it 



This helper is how we select the delayed ref to run once we've selected
the delayed ref head.  I need this exported to add a unit test for
delayed refs, and it's more natural home is in delayed-ref.c.  Rename it
to btrfs_select_delayed_ref and move it into delayed-ref.c.

Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5bc55a33

fs/btrfs/delayed-ref.c

+26 −0
Original line number Diff line number Diff line
@@ -555,6 +555,32 @@ void btrfs_delete_ref_head(const struct btrfs_fs_info *fs_info, 
		delayed_refs->num_heads_ready--;

}



struct btrfs_delayed_ref_node *btrfs_select_delayed_ref(struct btrfs_delayed_ref_head *head)

{

	struct btrfs_delayed_ref_node *ref;



	lockdep_assert_held(&head->mutex);

	lockdep_assert_held(&head->lock);



	if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))

		return NULL;



	/*

	 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.

	 * This is to prevent a ref count from going down to zero, which deletes

	 * the extent item from the extent tree, when there still are references

	 * to add, which would fail because they would not find the extent item.

	 */

	if (!list_empty(&head->ref_add_list))

		return list_first_entry(&head->ref_add_list,

					struct btrfs_delayed_ref_node, add_list);



	ref = rb_entry(rb_first_cached(&head->ref_tree),

		       struct btrfs_delayed_ref_node, ref_node);

	ASSERT(list_empty(&ref->add_list));

	return ref;

}



/*

 * Helper to insert the ref_node to the tail or merge with tail.

 *

fs/btrfs/delayed-ref.h

+1 −0
Original line number Diff line number Diff line
@@ -402,6 +402,7 @@ struct btrfs_delayed_ref_head *btrfs_select_ref_head( 
		struct btrfs_delayed_ref_root *delayed_refs);

void btrfs_unselect_ref_head(struct btrfs_delayed_ref_root *delayed_refs,

			     struct btrfs_delayed_ref_head *head);

struct btrfs_delayed_ref_node *btrfs_select_delayed_ref(struct btrfs_delayed_ref_head *head);



int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);

fs/btrfs/extent-tree.c

+1 −25
Original line number Diff line number Diff line
@@ -1803,30 +1803,6 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans, 
	return ret;

}



static inline struct btrfs_delayed_ref_node *

select_delayed_ref(struct btrfs_delayed_ref_head *head)

{

	struct btrfs_delayed_ref_node *ref;



	if (RB_EMPTY_ROOT(&head->ref_tree.rb_root))

		return NULL;



	/*

	 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.

	 * This is to prevent a ref count from going down to zero, which deletes

	 * the extent item from the extent tree, when there still are references

	 * to add, which would fail because they would not find the extent item.

	 */

	if (!list_empty(&head->ref_add_list))

		return list_first_entry(&head->ref_add_list,

				struct btrfs_delayed_ref_node, add_list);



	ref = rb_entry(rb_first_cached(&head->ref_tree),

		       struct btrfs_delayed_ref_node, ref_node);

	ASSERT(list_empty(&ref->add_list));

	return ref;

}



static struct btrfs_delayed_extent_op *cleanup_extent_op(

				struct btrfs_delayed_ref_head *head)

{
@@ -1959,7 +1935,7 @@ static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans, 
	lockdep_assert_held(&locked_ref->mutex);

	lockdep_assert_held(&locked_ref->lock);



	while ((ref = select_delayed_ref(locked_ref))) {

	while ((ref = btrfs_select_delayed_ref(locked_ref))) {

		if (ref->seq &&

		    btrfs_check_delayed_seq(fs_info, ref->seq)) {

			spin_unlock(&locked_ref->lock);