hello, We should hold the block_group_cache_lock while modifying the block groups red-black tree. Thank you, Signed-off-by: Yan Zheng <zheng.yan@oracle.com> --- diff -urp 1/fs/btrfs/extent-tree.c 2/fs/btrfs/extent-tree.c --- 1/fs/btrfs/extent-tree.c 2009-01-07 07:16:42.762364700 +0800 +++ 2/fs/btrfs/extent-tree.c 2009-01-21 10:41:38.000000000 +0800 @@ -5957,9 +5957,11 @@ int btrfs_remove_block_group(struct btrf path = btrfs_alloc_path(); BUG_ON(!path); - btrfs_remove_free_space_cache(block_group); + spin_lock(&root->fs_info->block_group_cache_lock); rb_erase(&block_group->cache_node, &root->fs_info->block_group_cache_tree); + spin_unlock(&root->fs_info->block_group_cache_lock); + btrfs_remove_free_space_cache(block_group); down_write(&block_group->space_info->groups_sem); list_del(&block_group->list); up_write(&block_group->space_info->groups_sem); -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html