Re: [PATCH v2] Lockd: pass network namespace to creation and destruction routines

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

11.04.2012 20:11, J. Bruce Fields пишет:
> On Thu, Mar 29, 2012 at 06:54:33PM +0400, Stanislav Kinsbursky wrote:
>> v2: dereference of most probably already released nlm_host removed in
>> nlmclnt_done() and reclaimer().
>
> Did you want this in Trond's tree or mine?
>

Your tree is preferred since I'm working with it.

> --b.
>
>>
>> These routines are called from locks reclaimer() kernel thread. This thread
>> works in "init_net" network context and currently relays on persence on lockd
>> thread and it's per-net resources. Thus lockd_up() and lockd_down() can't relay
>> on current network context. So let's pass corrent one into them.
>>
>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>
>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>
>> ---
>>   fs/lockd/clntlock.c        |   13 ++++++++-----
>>   fs/lockd/svc.c             |    7 +++----
>>   fs/nfsd/nfssvc.c           |    6 +++---
>>   include/linux/lockd/bind.h |    4 ++--
>>   4 files changed, 16 insertions(+), 14 deletions(-)
>>
>> diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
>> index ba1dc2e..ca0a080 100644
>> --- a/fs/lockd/clntlock.c
>> +++ b/fs/lockd/clntlock.c
>> @@ -56,7 +56,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
>>   	u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
>>   	int status;
>>
>> -	status = lockd_up();
>> +	status = lockd_up(nlm_init->net);
>>   	if (status<  0)
>>   		return ERR_PTR(status);
>>
>> @@ -65,7 +65,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
>>   				   nlm_init->hostname, nlm_init->noresvport,
>>   				   nlm_init->net);
>>   	if (host == NULL) {
>> -		lockd_down();
>> +		lockd_down(nlm_init->net);
>>   		return ERR_PTR(-ENOLCK);
>>   	}
>>
>> @@ -80,8 +80,10 @@ EXPORT_SYMBOL_GPL(nlmclnt_init);
>>    */
>>   void nlmclnt_done(struct nlm_host *host)
>>   {
>> +	struct net *net = host->net;
>> +
>>   	nlmclnt_release_host(host);
>> -	lockd_down();
>> +	lockd_down(net);
>>   }
>>   EXPORT_SYMBOL_GPL(nlmclnt_done);
>>
>> @@ -220,11 +222,12 @@ reclaimer(void *ptr)
>>   	struct nlm_wait	  *block;
>>   	struct file_lock *fl, *next;
>>   	u32 nsmstate;
>> +	struct net *net = host->net;
>>
>>   	allow_signal(SIGKILL);
>>
>>   	down_write(&host->h_rwsem);
>> -	lockd_up();	/* note: this cannot fail as lockd is already running */
>> +	lockd_up(net);	/* note: this cannot fail as lockd is already running */
>>
>>   	dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
>>
>> @@ -275,6 +278,6 @@ restart:
>>
>>   	/* Release host handle after use */
>>   	nlmclnt_release_host(host);
>> -	lockd_down();
>> +	lockd_down(net);
>>   	return 0;
>>   }
>> diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
>> index b34100e..ce4c80e 100644
>> --- a/fs/lockd/svc.c
>> +++ b/fs/lockd/svc.c
>> @@ -295,11 +295,10 @@ static void lockd_down_net(struct net *net)
>>   /*
>>    * Bring up the lockd process if it's not already up.
>>    */
>> -int lockd_up(void)
>> +int lockd_up(struct net *net)
>>   {
>>   	struct svc_serv *serv;
>>   	int		error = 0;
>> -	struct net *net = current->nsproxy->net_ns;
>>
>>   	mutex_lock(&nlmsvc_mutex);
>>   	/*
>> @@ -377,12 +376,12 @@ EXPORT_SYMBOL_GPL(lockd_up);
>>    * Decrement the user count and bring down lockd if we're the last.
>>    */
>>   void
>> -lockd_down(void)
>> +lockd_down(struct net *net)
>>   {
>>   	mutex_lock(&nlmsvc_mutex);
>>   	if (nlmsvc_users) {
>>   		if (--nlmsvc_users) {
>> -			lockd_down_net(current->nsproxy->net_ns);
>> +			lockd_down_net(net);
>>   			goto out;
>>   		}
>>   	} else {
>> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
>> index fce472f..0f3e35b 100644
>> --- a/fs/nfsd/nfssvc.c
>> +++ b/fs/nfsd/nfssvc.c
>> @@ -220,7 +220,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
>>   	ret = nfsd_init_socks(port);
>>   	if (ret)
>>   		goto out_racache;
>> -	ret = lockd_up();
>> +	ret = lockd_up(&init_net);
>>   	if (ret)
>>   		goto out_racache;
>>   	ret = nfs4_state_start();
>> @@ -229,7 +229,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
>>   	nfsd_up = true;
>>   	return 0;
>>   out_lockd:
>> -	lockd_down();
>> +	lockd_down(&init_net);
>>   out_racache:
>>   	nfsd_racache_shutdown();
>>   	return ret;
>> @@ -246,7 +246,7 @@ static void nfsd_shutdown(void)
>>   	if (!nfsd_up)
>>   		return;
>>   	nfs4_state_shutdown();
>> -	lockd_down();
>> +	lockd_down(&init_net);
>>   	nfsd_racache_shutdown();
>>   	nfsd_up = false;
>>   }
>> diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h
>> index 11a966e..4d24d64 100644
>> --- a/include/linux/lockd/bind.h
>> +++ b/include/linux/lockd/bind.h
>> @@ -54,7 +54,7 @@ extern void	nlmclnt_done(struct nlm_host *host);
>>
>>   extern int	nlmclnt_proc(struct nlm_host *host, int cmd,
>>   					struct file_lock *fl);
>> -extern int	lockd_up(void);
>> -extern void	lockd_down(void);
>> +extern int	lockd_up(struct net *net);
>> +extern void	lockd_down(struct net *net);
>>
>>   #endif /* LINUX_LOCKD_BIND_H */
>>


-- 
Best regards,
Stanislav Kinsbursky