[PATCH 0/6] Lockd: service start cleanup patch set

[PATCH 0/6] Lockd: service start cleanup patch set

[Stanislav Kinsbursky]

This patch set simplifies LockD start logic, makes code looks straight-forward
and clear.

The following series consists of:

---

Stanislav Kinsbursky (6):
      LockD: pass service to per-net up and down functions
      LockD: use existent per-net data function on service creation
      LockD: service creation function introduced
      LockD: move global usage counter manipulation from error path
      LockD: service start function introduced
      LockD: add debug message to start and stop functions


 fs/lockd/svc.c |  140 +++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 83 insertions(+), 57 deletions(-)

[PATCH 1/6] LockD: pass service to per-net up and down functions

[Stanislav Kinsbursky]

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

---
 fs/lockd/svc.c |   12 +++++-------
 1 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 3250f28..58ddc38 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -251,10 +251,9 @@ out_err:
 	return err;
 }
 
-static int lockd_up_net(struct net *net)
+static int lockd_up_net(struct svc_serv *serv, struct net *net)
 {
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
-	struct svc_serv *serv = nlmsvc_rqst->rq_server;
 	int error;
 
 	if (ln->nlmsvc_users++)
@@ -276,10 +275,9 @@ err_rpcb:
 	return error;
 }
 
-static void lockd_down_net(struct net *net)
+static void lockd_down_net(struct svc_serv *serv, struct net *net)
 {
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
-	struct svc_serv *serv = nlmsvc_rqst->rq_server;
 
 	if (ln->nlmsvc_users) {
 		if (--ln->nlmsvc_users == 0) {
@@ -307,7 +305,7 @@ int lockd_up(struct net *net)
 	 * Check whether we're already up and running.
 	 */
 	if (nlmsvc_rqst) {
-		error = lockd_up_net(net);
+		error = lockd_up_net(nlmsvc_rqst->rq_server, net);
 		goto out;
 	}
 
@@ -378,7 +376,7 @@ out:
 	return error;
 
 err_start:
-	lockd_down_net(net);
+	lockd_down_net(serv, net);
 	goto destroy_and_out;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
@@ -390,7 +388,7 @@ void
 lockd_down(struct net *net)
 {
 	mutex_lock(&nlmsvc_mutex);
-	lockd_down_net(net);
+	lockd_down_net(nlmsvc_rqst->rq_server, net);
 	if (nlmsvc_users) {
 		if (--nlmsvc_users)
 			goto out;

[PATCH 2/6] LockD: use existent per-net data function on service creation

[Stanislav Kinsbursky]

This patch also replaces svc_rpcb_setup() with svc_bind().

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

---
 fs/lockd/svc.c |   23 +++++++----------------
 1 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 58ddc38..71c6c31 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -259,9 +259,9 @@ static int lockd_up_net(struct svc_serv *serv, struct net *net)
 	if (ln->nlmsvc_users++)
 		return 0;
 
-	error = svc_rpcb_setup(serv, net);
+	error = svc_bind(serv, net);
 	if (error)
-		goto err_rpcb;
+		goto err_bind;
 
 	error = make_socks(serv, net);
 	if (error < 0)
@@ -270,7 +270,7 @@ static int lockd_up_net(struct svc_serv *serv, struct net *net)
 
 err_socks:
 	svc_rpcb_cleanup(serv, net);
-err_rpcb:
+err_bind:
 	ln->nlmsvc_users--;
 	return error;
 }
@@ -298,7 +298,6 @@ 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);
 	/*
@@ -324,17 +323,9 @@ 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;
-	}
-
-	ln->nlmsvc_users++;
-
-	error = make_socks(serv, net);
+	error = lockd_up_net(serv, net);
 	if (error < 0)
-		goto err_start;
+		goto err_net;
 
 	/*
 	 * Create the kernel thread and wait for it to start.
@@ -367,7 +358,7 @@ int lockd_up(struct net *net)
 	 * Note: svc_serv structures have an initial use count of 1,
 	 * so we exit through here on both success and failure.
 	 */
-destroy_and_out:
+err_net:
 	svc_destroy(serv);
 out:
 	if (!error)
@@ -377,7 +368,7 @@ out:
 
 err_start:
 	lockd_down_net(serv, net);
-	goto destroy_and_out;
+	goto err_net;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
 

[PATCH 3/6] LockD: service creation function introduced

[Stanislav Kinsbursky]

This function creates service if it's not exist, or increase usage counter of
the existent, and returns pointer to it.
Usage counter will be droppepd by svc_destroy() later in lockd_up().

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

---
 fs/lockd/svc.c |   38 +++++++++++++++++++++++++++-----------
 1 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 71c6c31..ad11ea7 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -291,21 +291,20 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
 	}
 }
 
-/*
- * Bring up the lockd process if it's not already up.
- */
-int lockd_up(struct net *net)
+static struct svc_serv *lockd_create_svc(void)
 {
 	struct svc_serv *serv;
-	int		error = 0;
 
-	mutex_lock(&nlmsvc_mutex);
 	/*
 	 * Check whether we're already up and running.
 	 */
 	if (nlmsvc_rqst) {
-		error = lockd_up_net(nlmsvc_rqst->rq_server, net);
-		goto out;
+		/*
+		 * Note: increase service usage, because later in case of error
+		 * svc_destroy() will be called.
+		 */
+		svc_get(nlmsvc_rqst->rq_server);
+		return nlmsvc_rqst->rq_server;
 	}
 
 	/*
@@ -316,11 +315,28 @@ int lockd_up(struct net *net)
 		printk(KERN_WARNING
 			"lockd_up: no pid, %d users??\n", nlmsvc_users);
 
-	error = -ENOMEM;
 	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
 	if (!serv) {
 		printk(KERN_WARNING "lockd_up: create service failed\n");
-		goto out;
+		return ERR_PTR(-ENOMEM);
+	}
+	return serv;
+}
+
+/*
+ * Bring up the lockd process if it's not already up.
+ */
+int lockd_up(struct net *net)
+{
+	struct svc_serv *serv;
+	int		error = 0;
+
+	mutex_lock(&nlmsvc_mutex);
+
+	serv = lockd_create_svc();
+	if (IS_ERR(serv)) {
+		error = PTR_ERR(serv);
+		goto err_create;
 	}
 
 	error = lockd_up_net(serv, net);
@@ -360,9 +376,9 @@ int lockd_up(struct net *net)
 	 */
 err_net:
 	svc_destroy(serv);
-out:
 	if (!error)
 		nlmsvc_users++;
+err_create:
 	mutex_unlock(&nlmsvc_mutex);
 	return error;
 

[PATCH 4/6] LockD: move global usage counter manipulation from error path

[Stanislav Kinsbursky]

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

---
 fs/lockd/svc.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index ad11ea7..53cd69e 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -329,7 +329,7 @@ static struct svc_serv *lockd_create_svc(void)
 int lockd_up(struct net *net)
 {
 	struct svc_serv *serv;
-	int		error = 0;
+	int error;
 
 	mutex_lock(&nlmsvc_mutex);
 
@@ -370,14 +370,13 @@ int lockd_up(struct net *net)
 		goto err_start;
 	}
 
+	nlmsvc_users++;
 	/*
 	 * Note: svc_serv structures have an initial use count of 1,
 	 * so we exit through here on both success and failure.
 	 */
 err_net:
 	svc_destroy(serv);
-	if (!error)
-		nlmsvc_users++;
 err_create:
 	mutex_unlock(&nlmsvc_mutex);
 	return error;

[PATCH 5/6] LockD: service start function introduced

[Stanislav Kinsbursky]

This is just a code move, which from my POW makes code looks better.
I.e. now on start we have 3 different stages:
1) Service creation.
2) Service per-net data allocation.
3) Service start.

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

---
 fs/lockd/svc.c |   67 +++++++++++++++++++++++++++++++++++---------------------
 1 files changed, 42 insertions(+), 25 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 53cd69e..b47bf77 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -291,6 +291,46 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
 	}
 }
 
+static int lockd_start_svc(struct svc_serv *serv)
+{
+	int error;
+
+	if (nlmsvc_rqst)
+		return 0;
+
+	/*
+	 * Create the kernel thread and wait for it to start.
+	 */
+	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
+	if (IS_ERR(nlmsvc_rqst)) {
+		error = PTR_ERR(nlmsvc_rqst);
+		printk(KERN_WARNING
+			"lockd_up: svc_rqst allocation failed, error=%d\n",
+			error);
+		goto out_rqst;
+	}
+
+	svc_sock_update_bufs(serv);
+	serv->sv_maxconn = nlm_max_connections;
+
+	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
+	if (IS_ERR(nlmsvc_task)) {
+		error = PTR_ERR(nlmsvc_task);
+		printk(KERN_WARNING
+			"lockd_up: kthread_run failed, error=%d\n", error);
+		goto out_task;
+	}
+	dprintk("lockd_up: service started\n");
+	return 0;
+
+out_task:
+	svc_exit_thread(nlmsvc_rqst);
+	nlmsvc_task = NULL;
+out_rqst:
+	nlmsvc_rqst = NULL;
+	return error;
+}
+
 static struct svc_serv *lockd_create_svc(void)
 {
 	struct svc_serv *serv;
@@ -343,32 +383,9 @@ int lockd_up(struct net *net)
 	if (error < 0)
 		goto err_net;
 
-	/*
-	 * Create the kernel thread and wait for it to start.
-	 */
-	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-	if (IS_ERR(nlmsvc_rqst)) {
-		error = PTR_ERR(nlmsvc_rqst);
-		nlmsvc_rqst = NULL;
-		printk(KERN_WARNING
-			"lockd_up: svc_rqst allocation failed, error=%d\n",
-			error);
-		goto err_start;
-	}
-
-	svc_sock_update_bufs(serv);
-	serv->sv_maxconn = nlm_max_connections;
-
-	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
-	if (IS_ERR(nlmsvc_task)) {
-		error = PTR_ERR(nlmsvc_task);
-		svc_exit_thread(nlmsvc_rqst);
-		nlmsvc_task = NULL;
-		nlmsvc_rqst = NULL;
-		printk(KERN_WARNING
-			"lockd_up: kthread_run failed, error=%d\n", error);
+	error = lockd_start_svc(serv);
+	if (error < 0)
 		goto err_start;
-	}
 
 	nlmsvc_users++;
 	/*

[PATCH 6/6] LockD: add debug message to start and stop functions

[Stanislav Kinsbursky]

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

---
 fs/lockd/svc.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index b47bf77..80938fd 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -266,6 +266,7 @@ static int lockd_up_net(struct svc_serv *serv, struct net *net)
 	error = make_socks(serv, net);
 	if (error < 0)
 		goto err_socks;
+	dprintk("lockd_up_net: per-net data created; net=%p\n", net);
 	return 0;
 
 err_socks:
@@ -283,6 +284,7 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net)
 		if (--ln->nlmsvc_users == 0) {
 			nlm_shutdown_hosts_net(net);
 			svc_shutdown_net(serv, net);
+			dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net);
 		}
 	} else {
 		printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n",
@@ -360,6 +362,7 @@ static struct svc_serv *lockd_create_svc(void)
 		printk(KERN_WARNING "lockd_up: create service failed\n");
 		return ERR_PTR(-ENOMEM);
 	}
+	dprintk("lockd_up: service created\n");
 	return serv;
 }
 
@@ -426,7 +429,9 @@ lockd_down(struct net *net)
 		BUG();
 	}
 	kthread_stop(nlmsvc_task);
+	dprintk("lockd_down: service stopped\n");
 	svc_exit_thread(nlmsvc_rqst);
+	dprintk("lockd_down: service destroyed\n");
 	nlmsvc_task = NULL;
 	nlmsvc_rqst = NULL;
 out:

Re: [PATCH 0/6] Lockd: service start cleanup patch set

[J. Bruce Fields]

On Wed, Apr 25, 2012 at 06:22:32PM +0400, Stanislav Kinsbursky wrote:
> This patch set simplifies LockD start logic, makes code looks straight-forward
> and clear.

I've applied and pushed these out.

I believe I now have everything from you except your latest grace-period
handling rfc.  Could you check and make sure that I'm not missing
anything else, and that I haven't messed up anything else?

--b.

> 
> The following series consists of:
> 
> ---
> 
> Stanislav Kinsbursky (6):
>       LockD: pass service to per-net up and down functions
>       LockD: use existent per-net data function on service creation
>       LockD: service creation function introduced
>       LockD: move global usage counter manipulation from error path
>       LockD: service start function introduced
>       LockD: add debug message to start and stop functions
> 
> 
>  fs/lockd/svc.c |  140 +++++++++++++++++++++++++++++++++-----------------------
>  1 files changed, 83 insertions(+), 57 deletions(-)
> 

Re: [PATCH 0/6] Lockd: service start cleanup patch set

[Stanislav Kinsbursky]

09.05.2012 23:08, J. Bruce Fields написал:
> On Wed, Apr 25, 2012 at 06:22:32PM +0400, Stanislav Kinsbursky wrote:
>> This patch set simplifies LockD start logic, makes code looks straight-forward
>> and clear.
> I've applied and pushed these out.
>
> I believe I now have everything from you except your latest grace-period
> handling rfc.  Could you check and make sure that I'm not missing
> anything else, and that I haven't messed up anything else?

Sure, Bruce.
I'll check and reply in few days.

> --b.
>
>> The following series consists of:
>>
>> ---
>>
>> Stanislav Kinsbursky (6):
>>        LockD: pass service to per-net up and down functions
>>        LockD: use existent per-net data function on service creation
>>        LockD: service creation function introduced
>>        LockD: move global usage counter manipulation from error path
>>        LockD: service start function introduced
>>        LockD: add debug message to start and stop functions
>>
>>
>>   fs/lockd/svc.c |  140 +++++++++++++++++++++++++++++++++-----------------------
>>   1 files changed, 83 insertions(+), 57 deletions(-)
>>

Re: [PATCH 0/6] Lockd: service start cleanup patch set

[Stanislav Kinsbursky]

On 09.05.2012 23:08, J. Bruce Fields wrote:
> On Wed, Apr 25, 2012 at 06:22:32PM +0400, Stanislav Kinsbursky wrote:
>> This patch set simplifies LockD start logic, makes code looks straight-forward
>> and clear.
>
> I've applied and pushed these out.
>
> I believe I now have everything from you except your latest grace-period
> handling rfc.  Could you check and make sure that I'm not missing
> anything else, and that I haven't messed up anything else?
>

Looks like you took all except patches for Trond (NFS callback containerization).
Thanks.


> --b.
>
>>
>> The following series consists of:
>>
>> ---
>>
>> Stanislav Kinsbursky (6):
>>        LockD: pass service to per-net up and down functions
>>        LockD: use existent per-net data function on service creation
>>        LockD: service creation function introduced
>>        LockD: move global usage counter manipulation from error path
>>        LockD: service start function introduced
>>        LockD: add debug message to start and stop functions
>>
>>
>>   fs/lockd/svc.c |  140 +++++++++++++++++++++++++++++++++-----------------------
>>   1 files changed, 83 insertions(+), 57 deletions(-)
>>


-- 
Best regards,
Stanislav Kinsbursky