1 files changed, 10 insertions, 0 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 0282033041e1..f631df870f64 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1999,6 +1999,16 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
                 min_bytes = max(bytes, (bytes + empty_size) >> 2);
 
         spin_lock(&block_group->tree_lock);
+
+        /*
+         * If we know we don't have enough space to make a cluster don't even
+         * bother doing all the work to try and find one.
+         */
+        if (block_group->free_space < min_bytes) {
+                spin_unlock(&block_group->tree_lock);
+                return -ENOSPC;
+        }
+
         spin_lock(&cluster->lock);
 
         /* someone already found a cluster, hooray */