btrfs: Free fully occupied bitmap in cluster

If there's no more free space in a bitmap, we should free it.

Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 850104f05178..cb0137e4047f 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1788,6 +1788,8 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
 
         ret = search_start;
         bitmap_clear_bits(block_group, entry, ret, bytes);
+        if (entry->bytes == 0)
+                free_bitmap(block_group, entry);
 out:
         spin_unlock(&cluster->lock);
         spin_unlock(&block_group->tree_lock);