Btrfs: do not create empty block group if we have allocated data

[cascardo/linux.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bd0f45f..745a619 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3402,6 +3402,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
        u32 count_meta = 0;
        u32 count_sys = 0;
        int chunk_reserved = 0;
+       u64 bytes_used = 0;
 
        /* step one make some room on all the devices */
        devices = &fs_info->fs_devices->devices;
@@ -3540,7 +3541,13 @@ again:
                        goto loop;
                }
 
-               if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && !chunk_reserved) {
+               ASSERT(fs_info->data_sinfo);
+               spin_lock(&fs_info->data_sinfo->lock);
+               bytes_used = fs_info->data_sinfo->bytes_used;
+               spin_unlock(&fs_info->data_sinfo->lock);
+
+               if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
+                   !chunk_reserved && !bytes_used) {
                        trans = btrfs_start_transaction(chunk_root, 0);
                        if (IS_ERR(trans)) {
                                mutex_unlock(&fs_info->delete_unused_bgs_mutex);