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Subject: Re: [PATCH v5 1/2] NFSD: delay unmount source's export after
 inter-server copy completed.
To:     "J. Bruce Fields" <bfields@fieldses.org>
Cc:     olga.kornievskaia@gmail.com, linux-nfs@vger.kernel.org,
        trondmy@hammerspace.com, chuck.lever@oracle.com
References: <20210517224330.9201-1-dai.ngo@oracle.com>
 <20210517224330.9201-2-dai.ngo@oracle.com>
 <20210518170456.GA25205@fieldses.org>
From:   dai.ngo@oracle.com
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On 5/18/21 10:04 AM, J. Bruce Fields wrote:
> On Mon, May 17, 2021 at 06:43:29PM -0400, Dai Ngo wrote:
>> +struct nfsd4_ssc_umount;
>>   
>>   enum {
>>   	/* cache misses due only to checksum comparison failures */
>> @@ -176,6 +177,10 @@ struct nfsd_net {
>>   	unsigned int             longest_chain_cachesize;
>>   
>>   	struct shrinker		nfsd_reply_cache_shrinker;
>> +
>> +	spinlock_t              nfsd_ssc_lock;
>> +	struct nfsd4_ssc_umount	*nfsd_ssc_umount;
> ...
>
>> +void nfsd4_ssc_init_umount_work(struct nfsd_net *nn)
>> +{
>> +	nn->nfsd_ssc_umount = kzalloc(sizeof(struct nfsd4_ssc_umount),
>> +					GFP_KERNEL);
>> +	if (!nn->nfsd_ssc_umount)
>> +		return;
> Is there any reason this needs to be allocated dynamically?  Let's just
> embed it in nfsd_net.
>
> Actually, I'm not convinced the separate structure definition's really
> that helpful:
>
>> +struct nfsd4_ssc_umount {
>> +	struct list_head nsu_list;
>> +	unsigned long nsu_expire;
>> +	wait_queue_head_t nsu_waitq;
>> +};
> How about just:
>
> 	struct nfsd_net {
> 	...
> 	/* tracking server-to-server copy mounts: */
> 	spinlock_t		nfsd_ssc_lock;
> 	struct list_head	nfsd_ssc_mount_list;
> 	unsigned long		nfsd_ssc_mount_expire;
> 	wait_queeu_head_t	nfsd_ssc_mount_waitq;
>
> or something along those lines?

I will move nfsd4_ssc_umount into nfsd_net.

-Dai

>
> --b.