diff --git a/[refs] b/[refs]
index 441e299d49eb..7a4b1d37a50c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4d479cf010d56ec9c54f3099992d039918f1296b
+refs/heads/master: 24a70313969fc3fc440216b40babdb42564acff3
diff --git a/trunk/fs/btrfs/free-space-cache.c b/trunk/fs/btrfs/free-space-cache.c
index aedacdbf77e2..6e5b7e463698 100644
--- a/trunk/fs/btrfs/free-space-cache.c
+++ b/trunk/fs/btrfs/free-space-cache.c
@@ -1849,7 +1849,13 @@ int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 		info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
 					  1, 0);
 		if (!info) {
-			WARN_ON(1);
+			/* the tree logging code might be calling us before we
+			 * have fully loaded the free space rbtree for this
+			 * block group.  So it is possible the entry won't
+			 * be in the rbtree yet at all.  The caching code
+			 * will make sure not to put it in the rbtree if
+			 * the logging code has pinned it.
+			 */
 			goto out_lock;
 		}
 	}