[PATCH 4/6] xfs: use memdup_user()

[Christoph Hellwig]

On Wed, Apr 08, 2009 at 03:08:04PM +0800, Li Zefan wrote:
> Remove open-coded memdup_user()
> 
> Signed-off-by: Li Zefan <lizf at cn.fujitsu.com>
> ---
>  fs/xfs/linux-2.6/xfs_ioctl.c   |   23 +++++++----------------
>  fs/xfs/linux-2.6/xfs_ioctl32.c |   12 ++++--------
>  2 files changed, 11 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
> index d0b4994..34eaab6 100644
> --- a/fs/xfs/linux-2.6/xfs_ioctl.c
> +++ b/fs/xfs/linux-2.6/xfs_ioctl.c
> @@ -489,17 +489,12 @@ xfs_attrmulti_attr_set(
>  	if (len > XATTR_SIZE_MAX)
>  		return EINVAL;
>  
> -	kbuf = kmalloc(len, GFP_KERNEL);
> -	if (!kbuf)
> -		return ENOMEM;
> -
> -	if (copy_from_user(kbuf, ubuf, len))
> -		goto out_kfree;
> +	kbuf = memdup_user(ubuf, len);
> +	if (IS_ERR(kbuf))
> +		return PTR_ERR(kbuf);

wouldn't NULL be a better error return for this kind of interface,
matching kmalloc?


Otherwise the patch looks good to me.

Reviewed-by: Christoph Hellwig <hch at lst.de>