Re: [PATCH 3/4]ext4: Return exchanged blocks count to user space in failure

[Peng Tao <bergwolf@gmail.com>]

Hi, Akira,

Akira Fujita wrote:
> ext4: Return exchanged blocks count to user space in failure
> 
> From: Akira Fujita <a-fujita@rs.jp.nec.com>
> 
> Return exchanged blocks count (moved_len) to user space,
> if ext4_move_extents() failed on the way.
Even with the patch, I still don't see how users can fix EXT4_IOC_MOVE_EXT failures,
because the orig file itself may be broken.
> 
> Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
> ---
>  fs/ext4/ioctl.c |    7 +++----
>  1 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index b0b434b..efd11c8 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -255,10 +255,9 @@ setversion_out:
>  					me.donor_start, me.len, &me.moved_len);
>  		fput(donor_filp);
> 
> -		if (!err)
> -			if (copy_to_user((struct move_extent *)arg,
> -				&me, sizeof(me)))
> -				return -EFAULT;
> +		if (copy_to_user((struct move_extent *)arg, &me, sizeof(me)))
> +			return -EFAULT;
> +
>  		return err;
>  	}
> --
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-- 
Best Regards,
Peng Tao
State Key Laboratory of Networking and Switching Technology
Beijing Univ. of Posts and Telecoms.