Re: [PATCH 6/6 v4] NFSD: Increase the reference of lockowner when coping file_lock

[Kinglong Mee <kinglongmee@gmail.com>]

On 8/20/2014 04:23, Jeff Layton wrote:
> On Tue, 19 Aug 2014 23:26:45 +0800
> Kinglong Mee <kinglongmee@gmail.com> wrote:
> 
>> v4: same as v3, no change
>> v3: Update based on Jeff's comments
>> v2: Fix bad using of struct file_lock_operations for handle the owner.
>>
>> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
>> ---
>>  fs/nfsd/nfs4state.c | 34 ++++++++++++++++++++++++++++++----
>>  1 file changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index e087a71..7161111 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -4869,9 +4869,31 @@ nfs4_transform_lock_offset(struct file_lock *lock)
>>  		lock->fl_end = OFFSET_MAX;
>>  }
>>  
>> -/* Hack!: For now, we're defining this just so we can use a pointer to it
>> - * as a unique cookie to identify our (NFSv4's) posix locks. */
>> +static inline struct nfs4_lockowner *
>> +nfs4_get_lockowner(struct nfs4_lockowner *lo)
>> +{
>> +	return lockowner(nfs4_get_stateowner(&lo->lo_owner));
>> +}
>> +
> 
> I'd probably not bother with this inline function. Just open code that
> into the callers.
> 
>> +static void nfsd4_fl_get_owner(struct file_lock *dst, struct file_lock *src)
>> +{
>> +	struct nfs4_lockowner *lo = (struct nfs4_lockowner *) src->fl_owner;
>> +	dst->fl_owner = (fl_owner_t) nfs4_get_lockowner(lo);
>> +}
>> +
>> +static void nfsd4_fl_put_owner(struct file_lock *fl)
>> +{
>> +	struct nfs4_lockowner *lo = (struct nfs4_lockowner *) fl->fl_owner;
>> +
>> +	if (lo) {
>> +		nfs4_put_stateowner(&lo->lo_owner);
>> +		fl->fl_owner = NULL;
>> +	}
>> +}
>> +
>>  static const struct lock_manager_operations nfsd_posix_mng_ops  = {
>> +	.lm_get_owner = nfsd4_fl_get_owner,
>> +	.lm_put_owner = nfsd4_fl_put_owner,
>>  };
>>  
>>  static inline void
>> @@ -5236,7 +5258,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>>  		status = nfserr_openmode;
>>  		goto out;
>>  	}
>> -	file_lock->fl_owner = (fl_owner_t)lock_sop;
>> +
>> +	file_lock->fl_owner = (fl_owner_t) nfs4_get_lockowner(lock_sop);
>>  	file_lock->fl_pid = current->tgid;
>>  	file_lock->fl_file = filp;
>>  	file_lock->fl_flags = FL_POSIX;
>> @@ -5403,6 +5426,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>>  	struct nfs4_ol_stateid *stp;
>>  	struct file *filp = NULL;
>>  	struct file_lock *file_lock = NULL;
>> +	struct nfs4_lockowner *lock_sop = NULL;
> 
> nit: Probably no need to initialize lock_sop to NULL. Even better, I'd
> just drop that and change the fl_owner assignment below.
> 
>>  	__be32 status;
>>  	int err;
>>  	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
>> @@ -5424,6 +5448,8 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>>  		status = nfserr_lock_range;
>>  		goto put_stateid;
>>  	}
>> +
>> +	lock_sop = lockowner(stp->st_stateowner);
>>  	file_lock = locks_alloc_lock();
>>  	if (!file_lock) {
>>  		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
>> @@ -5432,7 +5458,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>>  	}
>>  
>>  	file_lock->fl_type = F_UNLCK;
>> -	file_lock->fl_owner = (fl_owner_t)lockowner(stp->st_stateowner);
>> +	file_lock->fl_owner = (fl_owner_t) nfs4_get_lockowner(lock_sop);
> 
> I'd do this instead and not bother with a nfs4_get_lockowner at all...
> 
> 	file_lock->fl_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(stp->st_stateowner));
> 
>>  	file_lock->fl_pid = current->tgid;
>>  	file_lock->fl_file = filp;
>>  	file_lock->fl_flags = FL_POSIX;
> 
> But those are minor nits. This looks fine otherwise.
> 
> Bruce, if it's OK by you, I'll just take the whole series once Kinglong
> respins. It does touch some nfsd code, but it hopefully shouldn't cause
> much in the way of conflicts with anything you have queued for v3.18.

Thank you very much for your all comments before.
A new version have be sent, please have a check again.

thanks,
Kinglong Mee