On 2019/12/5 下午12:29, damenly.su@gmail.com wrote:
> From: Su Yue <Damenly_Su@gmx.com>
> 
> Simple copy and paste codes, remove useless lock operantions in progs.
> Th new coming lookup functions are named with suffix _kernel in
> temporary.
> 
> Signed-off-by: Su Yue <Damenly_Su@gmx.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Just an extra hint, it would be much better if we backport this
functions to block-group.c.

Thanks,
Qu
> ---
>  extent-tree.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 86 insertions(+)
> 
> diff --git a/extent-tree.c b/extent-tree.c
> index 4a3db029e811..ab576f8732a2 100644
> --- a/extent-tree.c
> +++ b/extent-tree.c
> @@ -164,6 +164,92 @@ err:
>  	return 0;
>  }
>  
> +/*
> + * This adds the block group to the fs_info rb tree for the block group cache
> + */
> +static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
> +				struct btrfs_block_group_cache *block_group)
> +{
> +	struct rb_node **p;
> +	struct rb_node *parent = NULL;
> +	struct btrfs_block_group_cache *cache;
> +
> +	p = &info->block_group_cache_tree.rb_node;
> +
> +	while (*p) {
> +		parent = *p;
> +		cache = rb_entry(parent, struct btrfs_block_group_cache,
> +				 cache_node);
> +		if (block_group->key.objectid < cache->key.objectid)
> +			p = &(*p)->rb_left;
> +		else if (block_group->key.objectid > cache->key.objectid)
> +			p = &(*p)->rb_right;
> +		else
> +			return -EEXIST;
> +	}
> +
> +	rb_link_node(&block_group->cache_node, parent, p);
> +	rb_insert_color(&block_group->cache_node,
> +			&info->block_group_cache_tree);
> +
> +	return 0;
> +}
> +
> +/*
> + * This will return the block group at or after bytenr if contains is 0, else
> + * it will return the block group that contains the bytenr
> + */
> +static struct btrfs_block_group_cache *block_group_cache_tree_search(
> +		struct btrfs_fs_info *info, u64 bytenr, int contains)
> +{
> +	struct btrfs_block_group_cache *cache, *ret = NULL;
> +	struct rb_node *n;
> +	u64 end, start;
> +
> +	n = info->block_group_cache_tree.rb_node;
> +
> +	while (n) {
> +		cache = rb_entry(n, struct btrfs_block_group_cache,
> +				 cache_node);
> +		end = cache->key.objectid + cache->key.offset - 1;
> +		start = cache->key.objectid;
> +
> +		if (bytenr < start) {
> +			if (!contains && (!ret || start < ret->key.objectid))
> +				ret = cache;
> +			n = n->rb_left;
> +		} else if (bytenr > start) {
> +			if (contains && bytenr <= end) {
> +				ret = cache;
> +				break;
> +			}
> +			n = n->rb_right;
> +		} else {
> +			ret = cache;
> +			break;
> +		}
> +	}
> +	return ret;
> +}
> +
> +/*
> + * Return the block group that starts at or after bytenr
> + */
> +struct btrfs_block_group_cache *btrfs_lookup_first_block_group_kernel(
> +		struct btrfs_fs_info *info, u64 bytenr)
> +{
> +	return block_group_cache_tree_search(info, bytenr, 0);
> +}
> +
> +/*
> + * Return the block group that contains the given bytenr
> + */
> +struct btrfs_block_group_cache *btrfs_lookup_block_group_kernel(
> +		struct btrfs_fs_info *info, u64 bytenr)
> +{
> +	return block_group_cache_tree_search(info, bytenr, 1);
> +}
> +
>  /*
>   * Return the block group that contains @bytenr, otherwise return the next one
>   * that starts after @bytenr
>