Re: [PATCH v3 03/10] NFSD: Clean up forgetting clients

[Bryan Schumaker <bjschuma@netapp.com>]

On 11/28/2012 11:47 AM, J. Bruce Fields wrote:
> On Wed, Nov 28, 2012 at 11:34:40AM -0500, Bryan Schumaker wrote:
>> On 11/28/2012 11:29 AM, J. Bruce Fields wrote:
>>> On Tue, Nov 27, 2012 at 09:35:12AM -0500, bjschuma@netapp.com wrote:
>>>> From: Bryan Schumaker <bjschuma@netapp.com>
>>>>
>>>> I added in a generic for-each loop that takes a pass over the
>>>> client_lru list and calls some function.  The next few patches will
>>>> update other operations to use this function as well.  A value of 0
>>>> still means "forget everything that is found".
>>>>
>>>> Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> ---
>>>> fs/nfsd/nfs4state.c | 23 ++++++++++++++++++----- 1 file changed, 18
>>>> insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index
>>>> 050a35e..07abca5 100644 --- a/fs/nfsd/nfs4state.c +++
>>>> b/fs/nfsd/nfs4state.c @@ -4591,19 +4591,32 @@
>>>> nfs4_check_open_reclaim(clientid_t *clid, bool sessions, struct
>>>> nfsd_net *nn)
>>>>  
>>>>  #ifdef CONFIG_NFSD_FAULT_INJECTION
>>>>  
>>>> -void nfsd_forget_clients(u64 num) +u64 nfsd_forget_client(struct
>>>> nfsd_net *nn, struct nfs4_client *clp, u64 max)
>>>
>>> It doesn't look like you really need nfsd_net?
>>
>> Not for this, but I find locks through the nn->ownerstr_hashtable
>> since the nfs4_client doesn't have a "cl_locks" list similar to
>> "cl_openowners" (unless there is something I'm missing...?).
> 
> That's because lockowners are all reachable from openowners (e.g. see
> how it's done in
> release_openowner->unhash_openowner->release_open_stateid->unhash_open_stateid->release_stateid_lockowners.
> Yeah, it's a little tangled.).
> 
> Alternatively you can get to the network namespace from the client
> (clp->net).

Both are good to know!  I'll look at getting lockowners from openowners first.

- Bryan

> 
> --b.
> 
>> I
>> figured I would introduce the function with the nfsd_net pointer
>> early, rather than change it in the next patch.
>>
>> I suppose I could have also put the locks patch first...
>>
>> - Bryan
>>
>>>
>>> --b.
>>>
>>>> +{ +	nfsd4_client_record_remove(clp); +
>>>> expire_client(clp); +	return 1; +} + +static u64
>>>> nfsd_for_n_state(u64 max, u64 (*func)(struct nfsd_net *, struct
>>>> nfs4_client *, u64)) { struct nfs4_client *clp, *next; -	int
>>>> count = 0; +	u64 count = 0; struct nfsd_net *nn =
>>>> net_generic(current->nsproxy->net_ns, nfsd_net_id);
>>>>  
>>>>  	list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) { -
>>>>  	expire_client(clp); -		if (++count == num) +
>>>>  	count += func(nn, clp, max - count); +		if ((max != 0)
>>>>  	&& (count >= max)) break; }
>>>>  
>>>> -	printk(KERN_INFO "NFSD: Forgot %d clients", count); +	return
>>>> count; +} + +void nfsd_forget_clients(u64 num) +{ +	u64
>>>> count = nfsd_for_n_state(num, nfsd_forget_client); +
>>>> printk(KERN_INFO "NFSD: Forgot %llu clients", count); }
>>>>  
>>>>  static void release_lockowner_sop(struct nfs4_stateowner *sop) --
>>>>  1.8.0.1
>>>>
>>
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