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Message-ID: <cb91ef9f-62ab-6bca-2bde-ac1977ec6f37@linux.alibaba.com>
Date:   Fri, 22 Apr 2022 10:44:19 +0800
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Subject: Re: [PATCH v9 03/21] cachefiles: unbind cachefiles gracefully in
 on-demand mode
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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,
        tianzichen@kuaishou.com, fannaihao@baidu.com,
        zhangjiachen.jaycee@bytedance.com
References: <20220415123614.54024-4-jefflexu@linux.alibaba.com>
 <20220415123614.54024-1-jefflexu@linux.alibaba.com>
 <1444916.1650549738@warthog.procyon.org.uk>
From:   JeffleXu <jefflexu@linux.alibaba.com>
In-Reply-To: <1444916.1650549738@warthog.procyon.org.uk>
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On 4/21/22 10:02 PM, David Howells wrote:
> Jeffle Xu <jefflexu@linux.alibaba.com> wrote:
> 
>> +	struct kref			unbind_pincount;/* refcount to do daemon unbind */
> 
> Please use refcount_t or atomic_t, especially as this isn't the refcount for
> the structure.

Okay, will be done in the next version.

> 
>> -	cachefiles_daemon_unbind(cache);
>> -
>>  	/* clean up the control file interface */
>>  	cache->cachefilesd = NULL;
>>  	file->private_data = NULL;
>>  	cachefiles_open = 0;
> 
> Please call cachefiles_daemon_unbind() before the cleanup.

Since the cachefiles_struct struct will be freed once the pincount is
decreased to 0, "cache->cachefilesd = NULL;" needs to be done before
decreasing the pincount. BTW, "cachefiles_open = 0;" indeed should be
done only when pincount has been decreased to 0.


-- 
Thanks,
Jeffle