On 2019/11/26 上午8:58, Marcos Paulo de Souza wrote:
> From: Marcos Paulo de Souza <mpdesouza@suse.com>
> 
> Remove some variables that are set only to be checked later, and never
> used.

Indeed.

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

Thanks,
Qu
> 
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
> ---
>  fs/btrfs/qgroup.c | 34 ++++++++++------------------------
>  1 file changed, 10 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index d4282e12f2a6..417fafb4b4f6 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1243,7 +1243,6 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
>  			      u64 dst)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *parent;
>  	struct btrfs_qgroup *member;
>  	struct btrfs_qgroup_list *list;
> @@ -1259,8 +1258,7 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
>  		return -ENOMEM;
>  
>  	mutex_lock(&fs_info->qgroup_ioctl_lock);
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root) {
> +	if (!fs_info->quota_root) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
> @@ -1307,7 +1305,6 @@ static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
>  				 u64 dst)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *parent;
>  	struct btrfs_qgroup *member;
>  	struct btrfs_qgroup_list *list;
> @@ -1320,8 +1317,7 @@ static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
>  	if (!tmp)
>  		return -ENOMEM;
>  
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root) {
> +	if (!fs_info->quota_root) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
> @@ -1387,11 +1383,11 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
>  	int ret = 0;
>  
>  	mutex_lock(&fs_info->qgroup_ioctl_lock);
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root) {
> +	if (!fs_info->quota_root) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
> +	quota_root = fs_info->quota_root;
>  	qgroup = find_qgroup_rb(fs_info, qgroupid);
>  	if (qgroup) {
>  		ret = -EEXIST;
> @@ -1416,14 +1412,12 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
>  int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *qgroup;
>  	struct btrfs_qgroup_list *list;
>  	int ret = 0;
>  
>  	mutex_lock(&fs_info->qgroup_ioctl_lock);
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root) {
> +	if (!fs_info->quota_root) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
> @@ -1465,7 +1459,6 @@ int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
>  		       struct btrfs_qgroup_limit *limit)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *qgroup;
>  	int ret = 0;
>  	/* Sometimes we would want to clear the limit on this qgroup.
> @@ -1475,8 +1468,7 @@ int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
>  	const u64 CLEAR_VALUE = -1;
>  
>  	mutex_lock(&fs_info->qgroup_ioctl_lock);
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root) {
> +	if (!fs_info->quota_root) {
>  		ret = -EINVAL;
>  		goto out;
>  	}
> @@ -2578,10 +2570,9 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
>  int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
>  {
>  	struct btrfs_fs_info *fs_info = trans->fs_info;
> -	struct btrfs_root *quota_root = fs_info->quota_root;
>  	int ret = 0;
>  
> -	if (!quota_root)
> +	if (!fs_info->quota_root)
>  		return ret;
>  
>  	spin_lock(&fs_info->qgroup_lock);
> @@ -2875,7 +2866,6 @@ static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
>  static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
>  			  enum btrfs_qgroup_rsv_type type)
>  {
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *qgroup;
>  	struct btrfs_fs_info *fs_info = root->fs_info;
>  	u64 ref_root = root->root_key.objectid;
> @@ -2894,8 +2884,7 @@ static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
>  		enforce = false;
>  
>  	spin_lock(&fs_info->qgroup_lock);
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root)
> +	if (!fs_info->quota_root)
>  		goto out;
>  
>  	qgroup = find_qgroup_rb(fs_info, ref_root);
> @@ -2962,7 +2951,6 @@ void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
>  			       u64 ref_root, u64 num_bytes,
>  			       enum btrfs_qgroup_rsv_type type)
>  {
> -	struct btrfs_root *quota_root;
>  	struct btrfs_qgroup *qgroup;
>  	struct ulist_node *unode;
>  	struct ulist_iterator uiter;
> @@ -2980,8 +2968,7 @@ void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
>  	}
>  	spin_lock(&fs_info->qgroup_lock);
>  
> -	quota_root = fs_info->quota_root;
> -	if (!quota_root)
> +	if (!fs_info->quota_root)
>  		goto out;
>  
>  	qgroup = find_qgroup_rb(fs_info, ref_root);
> @@ -3681,7 +3668,6 @@ void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
>  static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
>  				int num_bytes)
>  {
> -	struct btrfs_root *quota_root = fs_info->quota_root;
>  	struct btrfs_qgroup *qgroup;
>  	struct ulist_node *unode;
>  	struct ulist_iterator uiter;
> @@ -3689,7 +3675,7 @@ static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
>  
>  	if (num_bytes == 0)
>  		return;
> -	if (!quota_root)
> +	if (!fs_info->quota_root)
>  		return;
>  
>  	spin_lock(&fs_info->qgroup_lock);
>