[PATCH 0/3] SUNRPC: separate per-net data creation from service creation

[PATCH 0/3] SUNRPC: separate per-net data creation from service creation

[Stanislav Kinsbursky]

This is a cleanup patch set.
It will be followed my LockD start/stop cleanup patch set and NFS callback
service containerization patch set (yes, I forgot to implement it).

Today per-net data is created with service, and then is service is starting in
other network namespace. And thus it's destroyed with service too. Moreover,
network context for destroying of per-net data is taken from current process.
This is correct, but code looks ugly.
This patch set separates per-net data allocation from service allocation and
destruction.
IOW, per-net data have to be destroyed by service users - not service itself.

BTW, NFSd code become uglier with this patch set. Sorry.
But I assume, that these new ugly parts will be replaced later by NFSd service
containerization code.

The following series consists of:

---

Stanislav Kinsbursky (3):
      SUNRPC: new svc_bind() routine introduced
      SUNRPC: check rpcbind clients usage counter before decrement
      SUNRPC: move per-net operations from svc_destroy()


 fs/lockd/svc.c             |   30 +++++++++++++++++++-----------
 fs/nfs/callback.c          |   11 +++++++++++
 fs/nfsd/nfsctl.c           |    4 ++++
 fs/nfsd/nfssvc.c           |   16 ++++++++++++++++
 include/linux/sunrpc/svc.h |    1 +
 net/sunrpc/rpcb_clnt.c     |   12 +++++++-----
 net/sunrpc/svc.c           |   23 ++++++++++-------------
 7 files changed, 68 insertions(+), 29 deletions(-)

[PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[Stanislav Kinsbursky]

New routine is responsible for service registration in specified network
context.
The idea is to separate service creation from per-net operations.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 fs/lockd/svc.c             |    6 ++++++
 fs/nfs/callback.c          |    8 ++++++++
 fs/nfsd/nfssvc.c           |    9 +++++++++
 include/linux/sunrpc/svc.h |    1 +
 net/sunrpc/svc.c           |   19 ++++++++++---------
 5 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 1ead075..b7e92ed 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -324,6 +324,12 @@ int lockd_up(struct net *net)
 		goto out;
 	}
 
+	error = svc_bind(serv, net);
+	if (error < 0) {
+		printk(KERN_WARNING "lockd_up: bind service failed\n");
+		goto destroy_and_out;
+	}
+
 	error = make_socks(serv, net);
 	if (error < 0)
 		goto destroy_and_out;
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index eb95f50..26b38fb 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -17,6 +17,7 @@
 #include <linux/kthread.h>
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/bc_xprt.h>
+#include <linux/nsproxy.h>
 
 #include <net/inet_sock.h>
 
@@ -253,6 +254,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	char svc_name[12];
 	int ret = 0;
 	int minorversion_setup;
+	struct net *net = current->nsproxy->net_ns;
 
 	mutex_lock(&nfs_callback_mutex);
 	if (cb_info->users++ || cb_info->task != NULL) {
@@ -265,6 +267,12 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 		goto out_err;
 	}
 
+	ret = svc_bind(serv, net);
+	if (ret < 0) {
+		printk(KERN_WARNING "NFS: bind callback service failed\n");
+		goto out_err;
+	}
+
 	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
 					serv, xprt, &rqstp, &callback_svc);
 	if (!minorversion_setup) {
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index cb4d51d..0762f3c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/fs_struct.h>
 #include <linux/swap.h>
+#include <linux/nsproxy.h>
 
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/svcsock.h>
@@ -330,6 +331,8 @@ static int nfsd_get_default_max_blksize(void)
 
 int nfsd_create_serv(void)
 {
+	int error;
+
 	WARN_ON(!mutex_is_locked(&nfsd_mutex));
 	if (nfsd_serv) {
 		svc_get(nfsd_serv);
@@ -343,6 +346,12 @@ int nfsd_create_serv(void)
 	if (nfsd_serv == NULL)
 		return -ENOMEM;
 
+	error = svc_bind(nfsd_serv, current->nsproxy->net_ns);
+	if (error < 0) {
+		svc_destroy(nfsd_serv);
+		return error;
+	}
+
 	set_max_drc();
 	do_gettimeofday(&nfssvc_boot);		/* record boot time */
 	return 0;
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 51b29ac..2b43e02 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -416,6 +416,7 @@ struct svc_procedure {
  */
 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
+int svc_bind(struct svc_serv *serv, struct net *net);
 struct svc_serv *svc_create(struct svc_program *, unsigned int,
 			    void (*shutdown)(struct svc_serv *, struct net *net));
 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 4153846..e6d542c 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -407,6 +407,14 @@ static int svc_uses_rpcbind(struct svc_serv *serv)
 	return 0;
 }
 
+int svc_bind(struct svc_serv *serv, struct net *net)
+{
+	if (!svc_uses_rpcbind(serv))
+		return 0;
+	return svc_rpcb_setup(serv, net);
+}
+EXPORT_SYMBOL_GPL(svc_bind);
+
 /*
  * Create an RPC service
  */
@@ -471,15 +479,8 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 		spin_lock_init(&pool->sp_lock);
 	}
 
-	if (svc_uses_rpcbind(serv)) {
-		if (svc_rpcb_setup(serv, current->nsproxy->net_ns) < 0) {
-			kfree(serv->sv_pools);
-			kfree(serv);
-			return NULL;
-		}
-		if (!serv->sv_shutdown)
-			serv->sv_shutdown = svc_rpcb_cleanup;
-	}
+	if (svc_uses_rpcbind(serv) && (!serv->sv_shutdown))
+		serv->sv_shutdown = svc_rpcb_cleanup;
 
 	return serv;
 }

[PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[Stanislav Kinsbursky]

Registering service with svc_bind() can fail. In this case service will be
destroyed and during destruction it will try to unregister itself from rpcbind.
In this case unregister have to be skipped.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 net/sunrpc/rpcb_clnt.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 78ac39f..4c38b33 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
-	int shutdown;
+	int shutdown = 0;
 
 	spin_lock(&sn->rpcb_clnt_lock);
-	if (--sn->rpcb_users == 0) {
-		sn->rpcb_local_clnt = NULL;
-		sn->rpcb_local_clnt4 = NULL;
+	if (sn->rpcb_users) {
+		if (--sn->rpcb_users == 0) {
+			sn->rpcb_local_clnt = NULL;
+			sn->rpcb_local_clnt4 = NULL;
+		}
+		shutdown = !sn->rpcb_users;
 	}
-	shutdown = !sn->rpcb_users;
 	spin_unlock(&sn->rpcb_clnt_lock);
 
 	if (shutdown) {

Re: [PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[J. Bruce Fields]

On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
> Registering service with svc_bind() can fail. In this case service will be
> destroyed and during destruction it will try to unregister itself from rpcbind.
> In this case unregister have to be skipped.

Isn't this a preexisting bug, in which case perhaps Trond should at it
to his list of bugs to submit now?

--b.

> 
> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
> 
> ---
>  net/sunrpc/rpcb_clnt.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
> index 78ac39f..4c38b33 100644
> --- a/net/sunrpc/rpcb_clnt.c
> +++ b/net/sunrpc/rpcb_clnt.c
> @@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
>  	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
>  	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
>  	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
> -	int shutdown;
> +	int shutdown = 0;
>  
>  	spin_lock(&sn->rpcb_clnt_lock);
> -	if (--sn->rpcb_users == 0) {
> -		sn->rpcb_local_clnt = NULL;
> -		sn->rpcb_local_clnt4 = NULL;
> +	if (sn->rpcb_users) {
> +		if (--sn->rpcb_users == 0) {
> +			sn->rpcb_local_clnt = NULL;
> +			sn->rpcb_local_clnt4 = NULL;
> +		}
> +		shutdown = !sn->rpcb_users;
>  	}
> -	shutdown = !sn->rpcb_users;
>  	spin_unlock(&sn->rpcb_clnt_lock);
>  
>  	if (shutdown) {
> 

Re: [PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[Stanislav Kinsbursky]

On 27.04.2012 17:55, J. Bruce Fields wrote:
> On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
>> Registering service with svc_bind() can fail. In this case service will be
>> destroyed and during destruction it will try to unregister itself from rpcbind.
>> In this case unregister have to be skipped.
>
> Isn't this a preexisting bug, in which case perhaps Trond should at it
> to his list of bugs to submit now?
>

Not it's not.

Previously, in case of bind operations failure, rpcb_put_local() wasn't called, 
but service data was destroyed instead:

-	if (svc_uses_rpcbind(serv)) {
-		if (svc_rpcb_setup(serv, current->nsproxy->net_ns) < 0) {
-			kfree(serv->sv_pools);
-			kfree(serv);
-			return NULL;
-		}
-		if (!serv->sv_shutdown)
-			serv->sv_shutdown = svc_rpcb_cleanup;
-	}

Now (with svc_bind() introduction) service can be created, but svc_bind() could 
fail. And thus svc_destroy() have to be called. Which will call rpcb_put_local().

And the problem here that svc_bind() can fail before incrementing of rpcb usage 
counter.

> --b.
>
>>
>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>
>> ---
>>   net/sunrpc/rpcb_clnt.c |   12 +++++++-----
>>   1 files changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
>> index 78ac39f..4c38b33 100644
>> --- a/net/sunrpc/rpcb_clnt.c
>> +++ b/net/sunrpc/rpcb_clnt.c
>> @@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
>>   	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
>>   	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
>>   	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
>> -	int shutdown;
>> +	int shutdown = 0;
>>
>>   	spin_lock(&sn->rpcb_clnt_lock);
>> -	if (--sn->rpcb_users == 0) {
>> -		sn->rpcb_local_clnt = NULL;
>> -		sn->rpcb_local_clnt4 = NULL;
>> +	if (sn->rpcb_users) {
>> +		if (--sn->rpcb_users == 0) {
>> +			sn->rpcb_local_clnt = NULL;
>> +			sn->rpcb_local_clnt4 = NULL;
>> +		}
>> +		shutdown = !sn->rpcb_users;
>>   	}
>> -	shutdown = !sn->rpcb_users;
>>   	spin_unlock(&sn->rpcb_clnt_lock);
>>
>>   	if (shutdown) {
>>


-- 
Best regards,
Stanislav Kinsbursky

Re: [PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[J. Bruce Fields]

On Fri, Apr 27, 2012 at 06:08:13PM +0400, Stanislav Kinsbursky wrote:
> On 27.04.2012 17:55, J. Bruce Fields wrote:
> >On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
> >>Registering service with svc_bind() can fail. In this case service will be
> >>destroyed and during destruction it will try to unregister itself from rpcbind.
> >>In this case unregister have to be skipped.
> >
> >Isn't this a preexisting bug, in which case perhaps Trond should at it
> >to his list of bugs to submit now?
> >
> 
> Not it's not.
> 
> Previously, in case of bind operations failure, rpcb_put_local()
> wasn't called, but service data was destroyed instead:
> 
> -	if (svc_uses_rpcbind(serv)) {
> -		if (svc_rpcb_setup(serv, current->nsproxy->net_ns) < 0) {
> -			kfree(serv->sv_pools);
> -			kfree(serv);
> -			return NULL;
> -		}
> -		if (!serv->sv_shutdown)
> -			serv->sv_shutdown = svc_rpcb_cleanup;
> -	}
> 
> Now (with svc_bind() introduction) service can be created, but
> svc_bind() could fail. And thus svc_destroy() have to be called.
> Which will call rpcb_put_local().
> 
> And the problem here that svc_bind() can fail before incrementing of
> rpcb usage counter.

OK, but then you're fixing a bug that you just introduced with the
previous patch.

So this should be combined with the previous patch.

--b.

> 
> >--b.
> >
> >>
> >>Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
> >>
> >>---
> >>  net/sunrpc/rpcb_clnt.c |   12 +++++++-----
> >>  1 files changed, 7 insertions(+), 5 deletions(-)
> >>
> >>diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
> >>index 78ac39f..4c38b33 100644
> >>--- a/net/sunrpc/rpcb_clnt.c
> >>+++ b/net/sunrpc/rpcb_clnt.c
> >>@@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
> >>  	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
> >>  	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
> >>  	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
> >>-	int shutdown;
> >>+	int shutdown = 0;
> >>
> >>  	spin_lock(&sn->rpcb_clnt_lock);
> >>-	if (--sn->rpcb_users == 0) {
> >>-		sn->rpcb_local_clnt = NULL;
> >>-		sn->rpcb_local_clnt4 = NULL;
> >>+	if (sn->rpcb_users) {
> >>+		if (--sn->rpcb_users == 0) {
> >>+			sn->rpcb_local_clnt = NULL;
> >>+			sn->rpcb_local_clnt4 = NULL;
> >>+		}
> >>+		shutdown = !sn->rpcb_users;
> >>  	}
> >>-	shutdown = !sn->rpcb_users;
> >>  	spin_unlock(&sn->rpcb_clnt_lock);
> >>
> >>  	if (shutdown) {
> >>
> 
> 
> -- 
> Best regards,
> Stanislav Kinsbursky

Re: [PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[Stanislav Kinsbursky]

01.05.2012 01:45, J. Bruce Fields написал:
> On Fri, Apr 27, 2012 at 06:08:13PM +0400, Stanislav Kinsbursky wrote:
>> On 27.04.2012 17:55, J. Bruce Fields wrote:
>>> On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
>>>> Registering service with svc_bind() can fail. In this case service will be
>>>> destroyed and during destruction it will try to unregister itself from rpcbind.
>>>> In this case unregister have to be skipped.
>>> Isn't this a preexisting bug, in which case perhaps Trond should at it
>>> to his list of bugs to submit now?
>>>
>> Not it's not.
>>
>> Previously, in case of bind operations failure, rpcb_put_local()
>> wasn't called, but service data was destroyed instead:
>>
>> -	if (svc_uses_rpcbind(serv)) {
>> -		if (svc_rpcb_setup(serv, current->nsproxy->net_ns)<  0) {
>> -			kfree(serv->sv_pools);
>> -			kfree(serv);
>> -			return NULL;
>> -		}
>> -		if (!serv->sv_shutdown)
>> -			serv->sv_shutdown = svc_rpcb_cleanup;
>> -	}
>>
>> Now (with svc_bind() introduction) service can be created, but
>> svc_bind() could fail. And thus svc_destroy() have to be called.
>> Which will call rpcb_put_local().
>>
>> And the problem here that svc_bind() can fail before incrementing of
>> rpcb usage counter.
> OK, but then you're fixing a bug that you just introduced with the
> previous patch.
>
> So this should be combined with the previous patch.
>
> --b.

You, probably, right. I'll do this.
Thanks.

>>>> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com>
>>>>
>>>> ---
>>>>   net/sunrpc/rpcb_clnt.c |   12 +++++++-----
>>>>   1 files changed, 7 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
>>>> index 78ac39f..4c38b33 100644
>>>> --- a/net/sunrpc/rpcb_clnt.c
>>>> +++ b/net/sunrpc/rpcb_clnt.c
>>>> @@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
>>>>   	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
>>>>   	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
>>>>   	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
>>>> -	int shutdown;
>>>> +	int shutdown = 0;
>>>>
>>>>   	spin_lock(&sn->rpcb_clnt_lock);
>>>> -	if (--sn->rpcb_users == 0) {
>>>> -		sn->rpcb_local_clnt = NULL;
>>>> -		sn->rpcb_local_clnt4 = NULL;
>>>> +	if (sn->rpcb_users) {
>>>> +		if (--sn->rpcb_users == 0) {
>>>> +			sn->rpcb_local_clnt = NULL;
>>>> +			sn->rpcb_local_clnt4 = NULL;
>>>> +		}
>>>> +		shutdown = !sn->rpcb_users;
>>>>   	}
>>>> -	shutdown = !sn->rpcb_users;
>>>>   	spin_unlock(&sn->rpcb_clnt_lock);
>>>>
>>>>   	if (shutdown) {
>>>>
>>
>> -- 
>> Best regards,
>> Stanislav Kinsbursky

[PATCH 3/3] SUNRPC: move per-net operations from svc_destroy()

[Stanislav Kinsbursky]

The idea is to separate service destruction and per-net operations, because
these are two different things and it's mix looks ugly.

Notes:
1) For NFS server this patch looks ugly (sorry for that). But these place will be
rewritten soon during NFSd containerization.
2) LockD per-net counter increase int lockd_up() was moved prior to
make_socks() to make lockd_down_net() call safe in case of error.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 fs/lockd/svc.c    |   24 +++++++++++++-----------
 fs/nfs/callback.c |    3 +++
 fs/nfsd/nfsctl.c  |    4 ++++
 fs/nfsd/nfssvc.c  |    7 +++++++
 net/sunrpc/svc.c  |    4 ----
 5 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index b7e92ed..2c9ea37 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -299,6 +299,7 @@ int lockd_up(struct net *net)
 {
 	struct svc_serv *serv;
 	int		error = 0;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
 
 	mutex_lock(&nlmsvc_mutex);
 	/*
@@ -330,9 +331,11 @@ int lockd_up(struct net *net)
 		goto destroy_and_out;
 	}
 
+	ln->nlmsvc_users++;
+
 	error = make_socks(serv, net);
 	if (error < 0)
-		goto destroy_and_out;
+		goto err_start;
 
 	/*
 	 * Create the kernel thread and wait for it to start.
@@ -344,7 +347,7 @@ int lockd_up(struct net *net)
 		printk(KERN_WARNING
 			"lockd_up: svc_rqst allocation failed, error=%d\n",
 			error);
-		goto destroy_and_out;
+		goto err_start;
 	}
 
 	svc_sock_update_bufs(serv);
@@ -358,7 +361,7 @@ int lockd_up(struct net *net)
 		nlmsvc_rqst = NULL;
 		printk(KERN_WARNING
 			"lockd_up: kthread_run failed, error=%d\n", error);
-		goto destroy_and_out;
+		goto err_start;
 	}
 
 	/*
@@ -368,14 +371,14 @@ int lockd_up(struct net *net)
 destroy_and_out:
 	svc_destroy(serv);
 out:
-	if (!error) {
-		struct lockd_net *ln = net_generic(net, lockd_net_id);
-
-		ln->nlmsvc_users++;
+	if (!error)
 		nlmsvc_users++;
-	}
 	mutex_unlock(&nlmsvc_mutex);
 	return error;
+
+err_start:
+	lockd_down_net(net);
+	goto destroy_and_out;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
 
@@ -386,11 +389,10 @@ void
 lockd_down(struct net *net)
 {
 	mutex_lock(&nlmsvc_mutex);
+	lockd_down_net(net);
 	if (nlmsvc_users) {
-		if (--nlmsvc_users) {
-			lockd_down_net(net);
+		if (--nlmsvc_users)
 			goto out;
-		}
 	} else {
 		printk(KERN_ERR "lockd_down: no users! task=%p\n",
 			nlmsvc_task);
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 26b38fb..cff3940 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -314,6 +314,8 @@ out_err:
 	dprintk("NFS: Couldn't create callback socket or server thread; "
 		"err = %d\n", ret);
 	cb_info->users--;
+	if (serv)
+		svc_shutdown_net(serv, net);
 	goto out;
 }
 
@@ -328,6 +330,7 @@ void nfs_callback_down(int minorversion)
 	cb_info->users--;
 	if (cb_info->users == 0 && cb_info->task != NULL) {
 		kthread_stop(cb_info->task);
+		svc_shutdown_net(cb_info->serv, current->nsproxy->net_ns);
 		svc_exit_thread(cb_info->rqst);
 		cb_info->serv = NULL;
 		cb_info->rqst = NULL;
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7269988..efb3818 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -672,6 +672,8 @@ static ssize_t __write_ports_addfd(char *buf)
 
 	err = svc_addsock(nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT);
 	if (err < 0) {
+		if (nfsd_serv->sv_nrthreads == 1)
+			svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 		svc_destroy(nfsd_serv);
 		return err;
 	}
@@ -740,6 +742,8 @@ out_close:
 		svc_xprt_put(xprt);
 	}
 out_err:
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 	return err;
 }
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 0762f3c..3fffe6c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -426,6 +426,9 @@ int nfsd_set_nrthreads(int n, int *nthreads)
 		if (err)
 			break;
 	}
+
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 
 	return err;
@@ -473,6 +476,8 @@ out_shutdown:
 	if (error < 0 && !nfsd_up_before)
 		nfsd_shutdown();
 out_destroy:
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);		/* Release server */
 out:
 	mutex_unlock(&nfsd_mutex);
@@ -670,6 +675,8 @@ int nfsd_pool_stats_release(struct inode *inode, struct file *file)
 	int ret = seq_release(inode, file);
 	mutex_lock(&nfsd_mutex);
 	/* this function really, really should have been called svc_put() */
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 	mutex_unlock(&nfsd_mutex);
 	return ret;
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index e6d542c..b7210f5 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -537,8 +537,6 @@ EXPORT_SYMBOL_GPL(svc_shutdown_net);
 void
 svc_destroy(struct svc_serv *serv)
 {
-	struct net *net = current->nsproxy->net_ns;
-
 	dprintk("svc: svc_destroy(%s, %d)\n",
 				serv->sv_program->pg_name,
 				serv->sv_nrthreads);
@@ -553,8 +551,6 @@ svc_destroy(struct svc_serv *serv)
 
 	del_timer_sync(&serv->sv_temptimer);
 
-	svc_shutdown_net(serv, net);
-
 	/*
 	 * The last user is gone and thus all sockets have to be destroyed to
 	 * the point. Check this.

[PATCH v2 3/3] SUNRPC: move per-net operations from svc_destroy()

[Stanislav Kinsbursky]

v2:
1) Increase per-net usage counted in lockd_up_net(), because of note 2.

The idea is to separate service destruction and per-net operations, because
these are two different things and it's mix looks ugly.

Notes:
1) For NFS server this patch looks ugly (sorry for that). But these place will be
rewritten soon during NFSd containerization.
2) LockD per-net counter increase int lockd_up() was moved prior to
make_socks() to make lockd_down_net() call safe in case of error.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 fs/lockd/svc.c    |   27 +++++++++++++++------------
 fs/nfs/callback.c |    3 +++
 fs/nfsd/nfsctl.c  |    4 ++++
 fs/nfsd/nfssvc.c  |    7 +++++++
 net/sunrpc/svc.c  |    4 ----
 5 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index b7e92ed..3250f28 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -257,7 +257,7 @@ static int lockd_up_net(struct net *net)
 	struct svc_serv *serv = nlmsvc_rqst->rq_server;
 	int error;
 
-	if (ln->nlmsvc_users)
+	if (ln->nlmsvc_users++)
 		return 0;
 
 	error = svc_rpcb_setup(serv, net);
@@ -272,6 +272,7 @@ static int lockd_up_net(struct net *net)
 err_socks:
 	svc_rpcb_cleanup(serv, net);
 err_rpcb:
+	ln->nlmsvc_users--;
 	return error;
 }
 
@@ -299,6 +300,7 @@ int lockd_up(struct net *net)
 {
 	struct svc_serv *serv;
 	int		error = 0;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
 
 	mutex_lock(&nlmsvc_mutex);
 	/*
@@ -330,9 +332,11 @@ int lockd_up(struct net *net)
 		goto destroy_and_out;
 	}
 
+	ln->nlmsvc_users++;
+
 	error = make_socks(serv, net);
 	if (error < 0)
-		goto destroy_and_out;
+		goto err_start;
 
 	/*
 	 * Create the kernel thread and wait for it to start.
@@ -344,7 +348,7 @@ int lockd_up(struct net *net)
 		printk(KERN_WARNING
 			"lockd_up: svc_rqst allocation failed, error=%d\n",
 			error);
-		goto destroy_and_out;
+		goto err_start;
 	}
 
 	svc_sock_update_bufs(serv);
@@ -358,7 +362,7 @@ int lockd_up(struct net *net)
 		nlmsvc_rqst = NULL;
 		printk(KERN_WARNING
 			"lockd_up: kthread_run failed, error=%d\n", error);
-		goto destroy_and_out;
+		goto err_start;
 	}
 
 	/*
@@ -368,14 +372,14 @@ int lockd_up(struct net *net)
 destroy_and_out:
 	svc_destroy(serv);
 out:
-	if (!error) {
-		struct lockd_net *ln = net_generic(net, lockd_net_id);
-
-		ln->nlmsvc_users++;
+	if (!error)
 		nlmsvc_users++;
-	}
 	mutex_unlock(&nlmsvc_mutex);
 	return error;
+
+err_start:
+	lockd_down_net(net);
+	goto destroy_and_out;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
 
@@ -386,11 +390,10 @@ void
 lockd_down(struct net *net)
 {
 	mutex_lock(&nlmsvc_mutex);
+	lockd_down_net(net);
 	if (nlmsvc_users) {
-		if (--nlmsvc_users) {
-			lockd_down_net(net);
+		if (--nlmsvc_users)
 			goto out;
-		}
 	} else {
 		printk(KERN_ERR "lockd_down: no users! task=%p\n",
 			nlmsvc_task);
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 26b38fb..cff3940 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -314,6 +314,8 @@ out_err:
 	dprintk("NFS: Couldn't create callback socket or server thread; "
 		"err = %d\n", ret);
 	cb_info->users--;
+	if (serv)
+		svc_shutdown_net(serv, net);
 	goto out;
 }
 
@@ -328,6 +330,7 @@ void nfs_callback_down(int minorversion)
 	cb_info->users--;
 	if (cb_info->users == 0 && cb_info->task != NULL) {
 		kthread_stop(cb_info->task);
+		svc_shutdown_net(cb_info->serv, current->nsproxy->net_ns);
 		svc_exit_thread(cb_info->rqst);
 		cb_info->serv = NULL;
 		cb_info->rqst = NULL;
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7269988..efb3818 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -672,6 +672,8 @@ static ssize_t __write_ports_addfd(char *buf)
 
 	err = svc_addsock(nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT);
 	if (err < 0) {
+		if (nfsd_serv->sv_nrthreads == 1)
+			svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 		svc_destroy(nfsd_serv);
 		return err;
 	}
@@ -740,6 +742,8 @@ out_close:
 		svc_xprt_put(xprt);
 	}
 out_err:
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 	return err;
 }
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 0762f3c..3fffe6c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -426,6 +426,9 @@ int nfsd_set_nrthreads(int n, int *nthreads)
 		if (err)
 			break;
 	}
+
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 
 	return err;
@@ -473,6 +476,8 @@ out_shutdown:
 	if (error < 0 && !nfsd_up_before)
 		nfsd_shutdown();
 out_destroy:
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);		/* Release server */
 out:
 	mutex_unlock(&nfsd_mutex);
@@ -670,6 +675,8 @@ int nfsd_pool_stats_release(struct inode *inode, struct file *file)
 	int ret = seq_release(inode, file);
 	mutex_lock(&nfsd_mutex);
 	/* this function really, really should have been called svc_put() */
+	if (nfsd_serv->sv_nrthreads == 1)
+		svc_shutdown_net(nfsd_serv, current->nsproxy->net_ns);
 	svc_destroy(nfsd_serv);
 	mutex_unlock(&nfsd_mutex);
 	return ret;
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index e6d542c..b7210f5 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -537,8 +537,6 @@ EXPORT_SYMBOL_GPL(svc_shutdown_net);
 void
 svc_destroy(struct svc_serv *serv)
 {
-	struct net *net = current->nsproxy->net_ns;
-
 	dprintk("svc: svc_destroy(%s, %d)\n",
 				serv->sv_program->pg_name,
 				serv->sv_nrthreads);
@@ -553,8 +551,6 @@ svc_destroy(struct svc_serv *serv)
 
 	del_timer_sync(&serv->sv_temptimer);
 
-	svc_shutdown_net(serv, net);
-
 	/*
 	 * The last user is gone and thus all sockets have to be destroyed to
 	 * the point. Check this.

3.4.z nfsd backports

[J. Bruce Fields]

These three patches are all upstream, but required some conflict
resolution to backport, so I'm sending backported versions.

--b.

[PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[J. Bruce Fields]

From: Stanislav Kinsbursky <skinsbursky@parallels.com>

commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.

This new routine is responsible for service registration in a specified
network context.

The idea is to separate service creation from per-net operations.

Note also: since registering service with svc_bind() can fail, the
service will be destroyed and during destruction it will try to
unregister itself from rpcbind. In this case unregistration has to be
skipped.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/lockd/svc.c             |    6 ++++++
 fs/nfs/callback.c          |    8 ++++++++
 fs/nfsd/nfssvc.c           |    9 +++++++++
 include/linux/sunrpc/svc.h |    1 +
 net/sunrpc/rpcb_clnt.c     |   12 +++++++-----
 net/sunrpc/svc.c           |   19 ++++++++++---------
 6 files changed, 41 insertions(+), 14 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index f49b9af..b1d0708 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -325,6 +325,12 @@ int lockd_up(void)
 		goto out;
 	}
 
+	error = svc_bind(serv, net);
+	if (error < 0) {
+		printk(KERN_WARNING "lockd_up: bind service failed\n");
+		goto destroy_and_out;
+	}
+
 	error = make_socks(serv, net);
 	if (error < 0)
 		goto destroy_and_out;
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index eb95f50..26b38fb 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -17,6 +17,7 @@
 #include <linux/kthread.h>
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/bc_xprt.h>
+#include <linux/nsproxy.h>
 
 #include <net/inet_sock.h>
 
@@ -253,6 +254,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	char svc_name[12];
 	int ret = 0;
 	int minorversion_setup;
+	struct net *net = current->nsproxy->net_ns;
 
 	mutex_lock(&nfs_callback_mutex);
 	if (cb_info->users++ || cb_info->task != NULL) {
@@ -265,6 +267,12 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 		goto out_err;
 	}
 
+	ret = svc_bind(serv, net);
+	if (ret < 0) {
+		printk(KERN_WARNING "NFS: bind callback service failed\n");
+		goto out_err;
+	}
+
 	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
 					serv, xprt, &rqstp, &callback_svc);
 	if (!minorversion_setup) {
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 28dfad3..a6461f3 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/fs_struct.h>
 #include <linux/swap.h>
+#include <linux/nsproxy.h>
 
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/svcsock.h>
@@ -330,6 +331,8 @@ static int nfsd_get_default_max_blksize(void)
 
 int nfsd_create_serv(void)
 {
+	int error;
+
 	WARN_ON(!mutex_is_locked(&nfsd_mutex));
 	if (nfsd_serv) {
 		svc_get(nfsd_serv);
@@ -343,6 +346,12 @@ int nfsd_create_serv(void)
 	if (nfsd_serv == NULL)
 		return -ENOMEM;
 
+	error = svc_bind(nfsd_serv, current->nsproxy->net_ns);
+	if (error < 0) {
+		svc_destroy(nfsd_serv);
+		return error;
+	}
+
 	set_max_drc();
 	do_gettimeofday(&nfssvc_boot);		/* record boot time */
 	return 0;
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 51b29ac..2b43e02 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -416,6 +416,7 @@ struct svc_procedure {
  */
 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
+int svc_bind(struct svc_serv *serv, struct net *net);
 struct svc_serv *svc_create(struct svc_program *, unsigned int,
 			    void (*shutdown)(struct svc_serv *, struct net *net));
 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 78ac39f..4c38b33 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
-	int shutdown;
+	int shutdown = 0;
 
 	spin_lock(&sn->rpcb_clnt_lock);
-	if (--sn->rpcb_users == 0) {
-		sn->rpcb_local_clnt = NULL;
-		sn->rpcb_local_clnt4 = NULL;
+	if (sn->rpcb_users) {
+		if (--sn->rpcb_users == 0) {
+			sn->rpcb_local_clnt = NULL;
+			sn->rpcb_local_clnt4 = NULL;
+		}
+		shutdown = !sn->rpcb_users;
 	}
-	shutdown = !sn->rpcb_users;
 	spin_unlock(&sn->rpcb_clnt_lock);
 
 	if (shutdown) {
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 4153846..e6d542c 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -407,6 +407,14 @@ static int svc_uses_rpcbind(struct svc_serv *serv)
 	return 0;
 }
 
+int svc_bind(struct svc_serv *serv, struct net *net)
+{
+	if (!svc_uses_rpcbind(serv))
+		return 0;
+	return svc_rpcb_setup(serv, net);
+}
+EXPORT_SYMBOL_GPL(svc_bind);
+
 /*
  * Create an RPC service
  */
@@ -471,15 +479,8 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 		spin_lock_init(&pool->sp_lock);
 	}
 
-	if (svc_uses_rpcbind(serv)) {
-		if (svc_rpcb_setup(serv, current->nsproxy->net_ns) < 0) {
-			kfree(serv->sv_pools);
-			kfree(serv);
-			return NULL;
-		}
-		if (!serv->sv_shutdown)
-			serv->sv_shutdown = svc_rpcb_cleanup;
-	}
+	if (svc_uses_rpcbind(serv) && (!serv->sv_shutdown))
+		serv->sv_shutdown = svc_rpcb_cleanup;
 
 	return serv;
 }
-- 
1.7.9.5

Re: [PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[Greg KH]

On Mon, Jun 18, 2012 at 04:07:27PM -0400, J. Bruce Fields wrote:
> From: Stanislav Kinsbursky <skinsbursky@parallels.com>
> 
> commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.

Um, no, that's not what this commit id is at all.

Where did you get that from?  I kind of don't trust this series now,
care to fix these up with the correct git commit ids and resend them?

thanks,

greg k-h

Re: [PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[J. Bruce Fields]

On Wed, Jun 20, 2012 at 09:34:27AM -0700, Greg KH wrote:
> On Mon, Jun 18, 2012 at 04:07:27PM -0400, J. Bruce Fields wrote:
> > From: Stanislav Kinsbursky <skinsbursky@parallels.com>
> > 
> > commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.
> 
> Um, no, that's not what this commit id is at all.

Whoops, sorry!  Should have been 9793f7c88.  Upstream commits on #2 and
#3 are correct.

> Where did you get that from?  I kind of don't trust this series now,
> care to fix these up with the correct git commit ids and resend them?

Sure, I'll resend once I get the "4/3" patch sorted out.

(That got a form rejection--I assume it was the missing upstream commit
ID?  That's because there isn't one--3.4 requires a different fix.  But
I can point to where the bug got fixed upstream even if it isn't the
same.)

--b.

Re: [PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[Greg KH]

On Wed, Jun 20, 2012 at 02:09:29PM -0400, J. Bruce Fields wrote:
> On Wed, Jun 20, 2012 at 09:34:27AM -0700, Greg KH wrote:
> > On Mon, Jun 18, 2012 at 04:07:27PM -0400, J. Bruce Fields wrote:
> > > From: Stanislav Kinsbursky <skinsbursky@parallels.com>
> > > 
> > > commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.
> > 
> > Um, no, that's not what this commit id is at all.
> 
> Whoops, sorry!  Should have been 9793f7c88.  Upstream commits on #2 and
> #3 are correct.
> 
> > Where did you get that from?  I kind of don't trust this series now,
> > care to fix these up with the correct git commit ids and resend them?
> 
> Sure, I'll resend once I get the "4/3" patch sorted out.
> 
> (That got a form rejection--I assume it was the missing upstream commit
> ID?  That's because there isn't one--3.4 requires a different fix.  But
> I can point to where the bug got fixed upstream even if it isn't the
> same.)

You need to be really specific when sending a patch that is not
upstream, detailing why it isn't, and what different fix went in
upstream, if possible.

thanks,

greg k-h

Re: [PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[J. Bruce Fields]

On Wed, Jun 20, 2012 at 11:18:35AM -0700, Greg KH wrote:
> On Wed, Jun 20, 2012 at 02:09:29PM -0400, J. Bruce Fields wrote:
> > On Wed, Jun 20, 2012 at 09:34:27AM -0700, Greg KH wrote:
> > > On Mon, Jun 18, 2012 at 04:07:27PM -0400, J. Bruce Fields wrote:
> > > > From: Stanislav Kinsbursky <skinsbursky@parallels.com>
> > > > 
> > > > commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.
> > > 
> > > Um, no, that's not what this commit id is at all.
> > 
> > Whoops, sorry!  Should have been 9793f7c88.  Upstream commits on #2 and
> > #3 are correct.
> > 
> > > Where did you get that from?  I kind of don't trust this series now,
> > > care to fix these up with the correct git commit ids and resend them?
> > 
> > Sure, I'll resend once I get the "4/3" patch sorted out.
> > 
> > (That got a form rejection--I assume it was the missing upstream commit
> > ID?  That's because there isn't one--3.4 requires a different fix.  But
> > I can point to where the bug got fixed upstream even if it isn't the
> > same.)
> 
> You need to be really specific when sending a patch that is not
> upstream, detailing why it isn't, and what different fix went in
> upstream, if possible.

OK, looking at it closer I notice we can actually just take a different
fix directly from upstream, and then there's no problem.  But it took me
a few days to get around to setting up a test-case to make sure that
still did the job....

I'll pass along the revised series in a moment.--b.

Re: [PATCH 1/3] SUNRPC: new svc_bind() routine introduced

[J. Bruce Fields]

On Mon, Jun 25, 2012 at 04:33:32PM -0400, bfields wrote:
> On Wed, Jun 20, 2012 at 11:18:35AM -0700, Greg KH wrote:
> > On Wed, Jun 20, 2012 at 02:09:29PM -0400, J. Bruce Fields wrote:
> > > On Wed, Jun 20, 2012 at 09:34:27AM -0700, Greg KH wrote:
> > > > On Mon, Jun 18, 2012 at 04:07:27PM -0400, J. Bruce Fields wrote:
> > > > > From: Stanislav Kinsbursky <skinsbursky@parallels.com>
> > > > > 
> > > > > commit cd96891d48a945ca2011fbeceda73813d6286195 upstream.
> > > > 
> > > > Um, no, that's not what this commit id is at all.
> > > 
> > > Whoops, sorry!  Should have been 9793f7c88.  Upstream commits on #2 and
> > > #3 are correct.
> > > 
> > > > Where did you get that from?  I kind of don't trust this series now,
> > > > care to fix these up with the correct git commit ids and resend them?
> > > 
> > > Sure, I'll resend once I get the "4/3" patch sorted out.
> > > 
> > > (That got a form rejection--I assume it was the missing upstream commit
> > > ID?  That's because there isn't one--3.4 requires a different fix.  But
> > > I can point to where the bug got fixed upstream even if it isn't the
> > > same.)
> > 
> > You need to be really specific when sending a patch that is not
> > upstream, detailing why it isn't, and what different fix went in
> > upstream, if possible.
> 
> OK, looking at it closer I notice we can actually just take a different
> fix directly from upstream, and then there's no problem.  But it took me
> a few days to get around to setting up a test-case to make sure that
> still did the job....

(Oh, and my reproducer in case anyone wonders: build the following, run

	./namespace-exec /bin/bash

and

	mount -tproc proc /proc
	ps ax

just to verify you're in a new pid/mount namespace, then

	mount -tnfs yourserver:/somepath /mnt

then ^D out of the shell, and it should crash.)

--b.


#define _GNU_SOURCE
#include <unistd.h>
#include <signal.h>
#include <sched.h>
#include <sys/syscall.h>
#include <err.h>

int main(int argc, char *argv[])
{
	int pid;
	int flags = SIGCHLD;

	if (argc < 2)
		errx(1, "usage: %s command arg1 arg2 ...", argv[0]);
	flags |= CLONE_NEWNS|CLONE_NEWPID;
	pid = syscall(__NR_clone, flags, NULL);
	if (pid < 0)
		err(1, "clone failed");
	if (pid == 0) {
		/* child */
		int ret;

		ret = execv(argv[1], argv+1);
		if (ret)
			err(1,"failed to exec %s", argv[1]);
	}
	wait();
}