Re: retry： [PATCH] ovl: fix inode in utimes_common on overlayfs.

[Zhang AiHua <zhangaihua1@huawei.com>]

Hi,
     I have tested this patch, it's ok and looks better, thanks.

                            --AiHua

在 2016/8/10 16:01, Miklos Szeredi 写道:
> On Tue, Aug 09, 2016 at 11:00:03AM +0800, Zhang AiHua wrote:
>
>> From: Aihua Zhang <zhangaihua1@huawei.com>
>>
>> the check IS_IMMUTABLE(inode) is invalid in utimes_commmon,
>> the inode should point to upper rather than merge.
>>
>> the patch also fix the error in LTP(utimensat01).
>>
>> Signed-off-by: Aihua Zhang <zhangaihua1@huawei.com>
>
> Can you please try this alternative patch?
>
> Thanks,
> Miklos
>
> ---
>   fs/attr.c          |   15 +++++++++++++++
>   fs/utimes.c        |   17 +----------------
>   include/linux/fs.h |    1 +
>   3 files changed, 17 insertions(+), 16 deletions(-)
>
> --- a/fs/attr.c
> +++ b/fs/attr.c
> @@ -202,6 +202,21 @@ int notify_change(struct dentry * dentry
>   			return -EPERM;
>   	}
>
> +	/*
> +	 * If utimes(2) and friends are called with times == NULL (or both
> +	 * times are UTIME_NOW), then we need to check for write permission
> +	 */
> +	if (ia_valid & ATTR_TOUCH) {
> +                if (IS_IMMUTABLE(inode))
> +			return -EPERM;
> +
> +		if (!inode_owner_or_capable(inode)) {
> +			error = inode_permission(inode, MAY_WRITE);
> +			if (error)
> +				return error;
> +		}
> +	}
> +
>   	if ((ia_valid & ATTR_MODE)) {
>   		umode_t amode = attr->ia_mode;
>   		/* Flag setting protected by i_mutex */
> --- a/fs/utimes.c
> +++ b/fs/utimes.c
> @@ -87,21 +87,7 @@ static int utimes_common(struct path *pa
>   		 */
>   		newattrs.ia_valid |= ATTR_TIMES_SET;
>   	} else {
> -		/*
> -		 * If times is NULL (or both times are UTIME_NOW),
> -		 * then we need to check permissions, because
> -		 * inode_change_ok() won't do it.
> -		 */
> -		error = -EPERM;
> -                if (IS_IMMUTABLE(inode))
> -			goto mnt_drop_write_and_out;
> -
> -		error = -EACCES;
> -		if (!inode_owner_or_capable(inode)) {
> -			error = inode_permission(inode, MAY_WRITE);
> -			if (error)
> -				goto mnt_drop_write_and_out;
> -		}
> +		newattrs.ia_valid |= ATTR_TOUCH;
>   	}
>   retry_deleg:
>   	inode_lock(inode);
> @@ -113,7 +99,6 @@ static int utimes_common(struct path *pa
>   			goto retry_deleg;
>   	}
>
> -mnt_drop_write_and_out:
>   	mnt_drop_write(path->mnt);
>   out:
>   	return error;
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -224,6 +224,7 @@ typedef int (dio_iodone_t)(struct kiocb
>   #define ATTR_KILL_PRIV	(1 << 14)
>   #define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */
>   #define ATTR_TIMES_SET	(1 << 16)
> +#define ATTR_TOUCH	(1 << 17)
>
>   /*
>    * Whiteout is represented by a char device.  The following constants define the
>
> .
>