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Message-ID: <0cc3f6d6-ac89-05f6-23f3-68446a32d8b2@linux.alibaba.com>
Date:   Thu, 18 Aug 2022 18:47:15 +0800
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Subject: Re: [PATCH] cachefiles: fix error return code in
 cachefiles_ondemand_copen()
Content-Language: en-US
To:     Sun Ke <sunke32@huawei.com>, dhowells@redhat.com
Cc:     linux-cachefs@redhat.com, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
References: <20220818094939.1548183-1-sunke32@huawei.com>
From:   JeffleXu <jefflexu@linux.alibaba.com>
In-Reply-To: <20220818094939.1548183-1-sunke32@huawei.com>
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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