On 2019/12/18 下午1:18, damenly.su@xxxxxxxxx wrote:
> From: Su Yue <Damenly_Su@xxxxxxx>
>
> Change @cotnains to @next of block_group_cache_tree_search().
> Now, the function will try to search the block group containing
> the @bytenr. If not found, return NULL if @next is zero. Or
> It will return the next block group.
>
> Will be used in the later commit.
>
> Signed-off-by: Su Yue <Damenly_Su@xxxxxxx>
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
The @next looks pretty good, more clear than old @contains.
Thanks,
Qu
> ---
> extent-tree.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/extent-tree.c b/extent-tree.c
> index ab576f8732a2..fdfa29a2409f 100644
> --- a/extent-tree.c
> +++ b/extent-tree.c
> @@ -196,11 +196,15 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
> }
>
> /*
> - * 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
> + * This will return the block group which contains @bytenr if it exists.
> + * If found nothing, the return depends on @next.
> + *
> + * @next:
> + * if 0, return NULL if there's no block group containing the bytenr.
> + * if 1, return the block group which starts after @bytenr.
> */
> static struct btrfs_block_group_cache *block_group_cache_tree_search(
> - struct btrfs_fs_info *info, u64 bytenr, int contains)
> + struct btrfs_fs_info *info, u64 bytenr, int next)
> {
> struct btrfs_block_group_cache *cache, *ret = NULL;
> struct rb_node *n;
> @@ -215,11 +219,11 @@ static struct btrfs_block_group_cache *block_group_cache_tree_search(
> start = cache->key.objectid;
>
> if (bytenr < start) {
> - if (!contains && (!ret || start < ret->key.objectid))
> + if (next && (!ret || start < ret->key.objectid))
> ret = cache;
> n = n->rb_left;
> } else if (bytenr > start) {
> - if (contains && bytenr <= end) {
> + if (bytenr <= end) {
> ret = cache;
> break;
> }
> @@ -229,6 +233,7 @@ static struct btrfs_block_group_cache *block_group_cache_tree_search(
> break;
> }
> }
> +
> return ret;
> }
>
>
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