Re: [PATCH] xfs: lseek SEEK_DATA/SEEK_HOLE consolidation

[Dave Chinner <david@fromorbit.com>]

On Fri, Jun 21, 2013 at 09:27:58PM +0800, Jeff Liu wrote:
> From: Jie Liu <jeff.liu@oracle.com>
> 
> Consolidate lseek(2) SEEK_DATA/SEEK_HOLE according to the
> implementation of VFS lseek_execute():
> - if end up with a negative offset, return EINVAL if file
>   is not huge.
> - if end up with an offset larger than s_maxbytes, return
>   EINVAL as well.
> - reset file version to 0 if end up with an offset that is
>   not equal to the current file offset.
> 
> Signed-off-by: Jie Liu <jeff.liu@oracle.com>
> 
> ---
>  fs/xfs/xfs_file.c |   26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index a5f2042..dc42751 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1270,8 +1270,19 @@ xfs_seek_data(
>  	}
>  
>  out:
> -	if (offset != file->f_pos)
> +	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
> +		error = EINVAL;
> +		goto out_unlock;
> +	}
> +	if (offset > inode->i_sb->s_maxbytes) {
> +		error = EINVAL;
> +		goto out_unlock;
> +	}
> +
> +	if (offset != file->f_pos) {
>  		file->f_pos = offset;
> +		file->f_version = 0;
> +	}

Hi Jeff, why are you copy-n-pasting this code from lseek_execute()
rather than making lseek_execute() an exported function and calling
that directly? 

>  
>  out_unlock:
>  	xfs_iunlock_map_shared(ip, lock);
> @@ -1372,6 +1383,15 @@ xfs_seek_hole(
>  	}
>  
>  out:
> +	if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
> +		error = EINVAL;
> +		goto out_unlock;
> +	}
> +	if (offset > inode->i_sb->s_maxbytes) {
> +		error = EINVAL;
> +		goto out_unlock;
> +	}

These checks belong after we truncated offset to isize, don't they?
And that would make both of these functions simply require a call to
lseek_execute(), yes?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs