Re: [PATCH 15/20] ext4: get rid of ppath in ext4_split_convert_extents()

[Jan Kara <jack@suse.cz>]

On Wed 10-07-24 12:06:49, libaokun@huaweicloud.com wrote:
> From: Baokun Li <libaokun1@huawei.com>
> 
> The use of path and ppath is now very confusing, so to make the code more
> readable, pass path between functions uniformly, and get rid of ppath.
> 
> To get rid of the ppath in ext4_split_convert_extents(), the following is
> done here:
> 
>  * Its caller needs to update ppath if it uses ppath.
> 
> No functional changes.
> 
> Signed-off-by: Baokun Li <libaokun1@huawei.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza


> ---
>  fs/ext4/extents.c | 65 ++++++++++++++++++++++++-----------------------
>  1 file changed, 33 insertions(+), 32 deletions(-)
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 2a4f6c89858c..a41cbb8c4475 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -3699,21 +3699,21 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
>   * being filled will be convert to initialized by the end_io callback function
>   * via ext4_convert_unwritten_extents().
>   *
> - * Returns the size of unwritten extent to be written on success.
> + * The size of unwritten extent to be written is passed to the caller via the
> + * allocated pointer. Return an extent path pointer on success, or an error
> + * pointer on failure.
>   */
> -static int ext4_split_convert_extents(handle_t *handle,
> +static struct ext4_ext_path *ext4_split_convert_extents(handle_t *handle,
>  					struct inode *inode,
>  					struct ext4_map_blocks *map,
> -					struct ext4_ext_path **ppath,
> -					int flags)
> +					struct ext4_ext_path *path,
> +					int flags, unsigned int *allocated)
>  {
> -	struct ext4_ext_path *path = *ppath;
>  	ext4_lblk_t eof_block;
>  	ext4_lblk_t ee_block;
>  	struct ext4_extent *ex;
>  	unsigned int ee_len;
>  	int split_flag = 0, depth;
> -	unsigned int allocated = 0;
>  
>  	ext_debug(inode, "logical block %llu, max_blocks %u\n",
>  		  (unsigned long long)map->m_lblk, map->m_len);
> @@ -3741,14 +3741,8 @@ static int ext4_split_convert_extents(handle_t *handle,
>  		split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
>  	}
>  	flags |= EXT4_GET_BLOCKS_PRE_IO;
> -	path = ext4_split_extent(handle, inode, path, map, split_flag, flags,
> -				 &allocated);
> -	if (IS_ERR(path)) {
> -		*ppath = NULL;
> -		return PTR_ERR(path);
> -	}
> -	*ppath = path;
> -	return allocated;
> +	return ext4_split_extent(handle, inode, path, map, split_flag, flags,
> +				 allocated);
>  }
>  
>  static int ext4_convert_unwritten_extents_endio(handle_t *handle,
> @@ -3784,11 +3778,14 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
>  			     inode->i_ino, (unsigned long long)ee_block, ee_len,
>  			     (unsigned long long)map->m_lblk, map->m_len);
>  #endif
> -		err = ext4_split_convert_extents(handle, inode, map, ppath,
> -						 EXT4_GET_BLOCKS_CONVERT);
> -		if (err < 0)
> -			return err;
> -		path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
> +		path = ext4_split_convert_extents(handle, inode, map, path,
> +						EXT4_GET_BLOCKS_CONVERT, NULL);
> +		if (IS_ERR(path)) {
> +			*ppath = NULL;
> +			return PTR_ERR(path);
> +		}
> +
> +		path = ext4_find_extent(inode, map->m_lblk, path, 0);
>  		if (IS_ERR(path)) {
>  			*ppath = NULL;
>  			return PTR_ERR(path);
> @@ -3845,11 +3842,14 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
>  		  (unsigned long long)ee_block, ee_len);
>  
>  	if (ee_block != map->m_lblk || ee_len > map->m_len) {
> -		err = ext4_split_convert_extents(handle, inode, map, ppath,
> -				EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
> -		if (err < 0)
> -			return err;
> -		path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
> +		path = ext4_split_convert_extents(handle, inode, map, path,
> +				EXT4_GET_BLOCKS_CONVERT_UNWRITTEN, NULL);
> +		if (IS_ERR(path)) {
> +			*ppath = NULL;
> +			return PTR_ERR(path);
> +		}
> +
> +		path = ext4_find_extent(inode, map->m_lblk, path, 0);
>  		if (IS_ERR(path)) {
>  			*ppath = NULL;
>  			return PTR_ERR(path);
> @@ -3915,19 +3915,20 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
>  
>  	/* get_block() before submitting IO, split the extent */
>  	if (flags & EXT4_GET_BLOCKS_PRE_IO) {
> -		ret = ext4_split_convert_extents(handle, inode, map, ppath,
> -					 flags | EXT4_GET_BLOCKS_CONVERT);
> -		if (ret < 0) {
> -			err = ret;
> +		*ppath = ext4_split_convert_extents(handle, inode, map, *ppath,
> +				flags | EXT4_GET_BLOCKS_CONVERT, &allocated);
> +		if (IS_ERR(*ppath)) {
> +			err = PTR_ERR(*ppath);
> +			*ppath = NULL;
>  			goto out2;
>  		}
>  		/*
> -		 * shouldn't get a 0 return when splitting an extent unless
> +		 * shouldn't get a 0 allocated when splitting an extent unless
>  		 * m_len is 0 (bug) or extent has been corrupted
>  		 */
> -		if (unlikely(ret == 0)) {
> +		if (unlikely(allocated == 0)) {
>  			EXT4_ERROR_INODE(inode,
> -					 "unexpected ret == 0, m_len = %u",
> +					 "unexpected allocated == 0, m_len = %u",
>  					 map->m_len);
>  			err = -EFSCORRUPTED;
>  			goto out2;
> @@ -3988,9 +3989,9 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
>  		err = -EFSCORRUPTED;
>  		goto out2;
>  	}
> +	allocated = ret;
>  
>  out:
> -	allocated = ret;
>  	map->m_flags |= EXT4_MAP_NEW;
>  map_out:
>  	map->m_flags |= EXT4_MAP_MAPPED;
> -- 
> 2.39.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR