Re: [PATCH 4/5] xfs: remove xfs_file_wait_for_io

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Oct 19, 2016 at 02:47:27PM +0200, Christoph Hellwig wrote:
> filemap_write_and_wait_range operates on full pages, so there is no need
> for the rounding operations.  Additionally this allows us to micro-optimize
> by skipping the second inode_dio_wait for a intra-file clone.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

> ---
>  fs/xfs/xfs_file.c | 39 ++++++++++-----------------------------
>  1 file changed, 10 insertions(+), 29 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 0960264..a61be33 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -947,32 +947,6 @@ xfs_file_fallocate(
>  	return error;
>  }
>  
> -/*
> - * Flush all file writes out to disk.
> - */
> -static int
> -xfs_file_wait_for_io(
> -	struct inode	*inode,
> -	loff_t		offset,
> -	size_t		len)
> -{
> -	loff_t		rounding;
> -	loff_t		ioffset;
> -	loff_t		iendoffset;
> -	loff_t		bs;
> -	int		ret;
> -
> -	bs = inode->i_sb->s_blocksize;
> -	inode_dio_wait(inode);
> -
> -	rounding = max_t(xfs_off_t, bs, PAGE_SIZE);
> -	ioffset = round_down(offset, rounding);
> -	iendoffset = round_up(offset + len, rounding) - 1;
> -	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
> -					   iendoffset);
> -	return ret;
> -}
> -
>  /* Hook up to the VFS reflink function */
>  STATIC int
>  xfs_file_share_range(
> @@ -1069,11 +1043,18 @@ xfs_file_share_range(
>  	if (same_inode && pos_out + blen > pos_in && pos_out < pos_in + blen)
>  		goto out_unlock;
>  
> -	/* Wait for the completion of any pending IOs on srcfile */
> -	ret = xfs_file_wait_for_io(inode_in, pos_in, len);
> +	/* Wait for the completion of any pending IOs on both files */
> +	inode_dio_wait(inode_in);
> +	if (!same_inode)
> +		inode_dio_wait(inode_out);
> +
> +	ret = filemap_write_and_wait_range(inode_in->i_mapping,
> +			pos_in, pos_in + len - 1);
>  	if (ret)
>  		goto out_unlock;
> -	ret = xfs_file_wait_for_io(inode_out, pos_out, len);
> +
> +	ret = filemap_write_and_wait_range(inode_out->i_mapping,
> +			pos_out, pos_out + len - 1);
>  	if (ret)
>  		goto out_unlock;
>  
> -- 
> 2.1.4
>