Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <a1543a27-7f52-266b-dd67-972902e80e8e@linux.alibaba.com>
Date:   Mon, 21 Mar 2022 22:43:20 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.6.1
Subject: Re: [PATCH v5 04/22] cachefiles: notify user daemon with anon_fd when
 looking up cookie
Content-Language: en-US
To:     David Howells <dhowells@redhat.com>
Cc:     linux-cachefs@redhat.com, xiang@kernel.org, chao@kernel.org,
        linux-erofs@lists.ozlabs.org, torvalds@linux-foundation.org,
        gregkh@linuxfoundation.org, willy@infradead.org,
        linux-fsdevel@vger.kernel.org, joseph.qi@linux.alibaba.com,
        bo.liu@linux.alibaba.com, tao.peng@linux.alibaba.com,
        gerry@linux.alibaba.com, eguan@linux.alibaba.com,
        linux-kernel@vger.kernel.org, luodaowen.backend@bytedance.com
References: <20220316131723.111553-5-jefflexu@linux.alibaba.com>
 <20220316131723.111553-1-jefflexu@linux.alibaba.com>
 <1029248.1647871294@warthog.procyon.org.uk>
From:   JeffleXu <jefflexu@linux.alibaba.com>
In-Reply-To: <1029248.1647871294@warthog.procyon.org.uk>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 3/21/22 10:01 PM, David Howells wrote:
> Jeffle Xu <jefflexu@linux.alibaba.com> wrote:
> 
>> +	read_lock(&cache->reqs_lock);
>> +
>> +	/* recheck dead state under lock */
>> +	if (test_bit(CACHEFILES_DEAD, &cache->flags)) {
>> +		read_unlock(&cache->reqs_lock);
>> +		ret = -EIO;
>> +		goto out;
>> +	}
>> +
>> +	xa_lock(xa);
>> +	ret = __xa_alloc(xa, &id, req, xa_limit_32b, GFP_KERNEL);
> 
> You're holding a spinlock.  You can't use GFP_KERNEL.

Oh yes... I've dropped into this for second time... Sorry for that.

> 
>> +static int cachefiles_ondemand_cinit(struct cachefiles_cache *cache, char *args)
>> +{
>> ...
>> +	tmp = kstrdup(args, GFP_KERNEL);
> 
> No need to copy the string.  The caller already did that and added a NUL for
> good measure.

Right.


> 
> I would probably move most of the functions added in this patch to
> fs/cachefiles/ondemand.c.

Alright.


-- 
Thanks,
Jeffle