Commit cd1cfc49 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: add a barrier before a waitqueue_active check 



We were missing wakeups on the delayed ref waitqueue due
to races on waitqueue_active.

Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent e9fbcb42

fs/btrfs/extent-tree.c

+1 −0
Original line number Diff line number Diff line
@@ -5294,6 +5294,7 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, 
	rb_erase(&head->node.rb_node, &delayed_refs->root);



	delayed_refs->num_entries--;

	smp_mb();

	if (waitqueue_active(&root->fs_info->tree_mod_seq_wait))

		wake_up(&root->fs_info->tree_mod_seq_wait);