Re: [PATCH] cachefiles: fix error return code in cachefiles_ondemand_copen()

[JeffleXu <jefflexu@linux.alibaba.com>]

On 8/18/22 5:49 PM, Sun Ke wrote:
> If size < 0; open request will fail, but cachefiles_ondemand_copen return 0.

Hi, this is a deliberate design. The cache_size field of copen is
specified by the user daemon. If cache_size < 0, then the OPEN request
is expected to fail, while copen itself shall succeed.

> Fix to return a negative error code.
> 
> Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie")
> Signed-off-by: Sun Ke <sunke32@huawei.com>
> ---
>  fs/cachefiles/ondemand.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
> index 1fee702d5529..a31d3ff0ce5f 100644
> --- a/fs/cachefiles/ondemand.c
> +++ b/fs/cachefiles/ondemand.c
> @@ -161,6 +161,7 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args)
>  		if (!IS_ERR_VALUE(size))
>  			size = -EINVAL;

However, it is indeed unexpected when cache_size is an invalid error
code. How about:

		if (!IS_ERR_VALUE(size))
-			size= -EINVAL;
+			ret = size = -EINVAL;
		req->error = size;
		goto out;
	}

>  		req->error = size;
> +		ret = -EINVAL;
>  		goto out;
>  	}
>  

-- 
Thanks,
Jingbo