2010-09-21 20:38:13

by Anna Schumaker

[permalink] [raw]
Subject: [PATCH 2/2] lockd: Mostly remove BKL from the server

lockd: Mostly remove BKL from the server

This patch removes all but one call to lock_kernel() from the server.

Signed-off-by: Bryan Schumaker <[email protected]>
---
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 031c656..a336e83 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -230,9 +230,7 @@ static void nlm4svc_callback_exit(struct rpc_task *task, void *data)

static void nlm4svc_callback_release(void *data)
{
- lock_kernel();
nlm_release_call(data);
- unlock_kernel();
}

static const struct rpc_call_ops nlm4svc_callback_ops = {
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 84055d3..6f1ef00 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -52,12 +52,13 @@ static const struct rpc_call_ops nlmsvc_grant_ops;
* The list of blocked locks to retry
*/
static LIST_HEAD(nlm_blocked);
+static DEFINE_SPINLOCK(nlm_blocked_lock);

/*
* Insert a blocked lock into the global list
*/
static void
-nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
+nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when)
{
struct nlm_block *b;
struct list_head *pos;
@@ -87,6 +88,13 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
block->b_when = when;
}

+static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
+{
+ spin_lock(&nlm_blocked_lock);
+ nlmsvc_insert_block_locked(block, when);
+ spin_unlock(&nlm_blocked_lock);
+}
+
/*
* Remove a block from the global list
*/
@@ -94,7 +102,9 @@ static inline void
nlmsvc_remove_block(struct nlm_block *block)
{
if (!list_empty(&block->b_list)) {
+ spin_lock(&nlm_blocked_lock);
list_del_init(&block->b_list);
+ spin_unlock(&nlm_blocked_lock);
nlmsvc_release_block(block);
}
}
@@ -651,7 +661,7 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
struct nlm_block *block;
int rc = -ENOENT;

- lock_kernel();
+ spin_lock(&nlm_blocked_lock);
list_for_each_entry(block, &nlm_blocked, b_list) {
if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
@@ -665,13 +675,13 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
} else if (result == 0)
block->b_granted = 1;

- nlmsvc_insert_block(block, 0);
+ nlmsvc_insert_block_locked(block, 0);
svc_wake_up(block->b_daemon);
rc = 0;
break;
}
}
- unlock_kernel();
+ spin_unlock(&nlm_blocked_lock);
if (rc == -ENOENT)
printk(KERN_WARNING "lockd: grant for unknown block\n");
return rc;
@@ -803,7 +813,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)

dprintk("lockd: GRANT_MSG RPC callback\n");

- lock_kernel();
+ spin_lock(&nlm_blocked_lock);
/* if the block is not on a list at this point then it has
* been invalidated. Don't try to requeue it.
*
@@ -825,19 +835,20 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
/* Call was successful, now wait for client callback */
timeout = 60 * HZ;
}
- nlmsvc_insert_block(block, timeout);
+ nlmsvc_insert_block_locked(block, timeout);
svc_wake_up(block->b_daemon);
out:
- unlock_kernel();
+ spin_unlock(&nlm_blocked_lock);
}

+/*
+ * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an
+ * .rpc_release rpc_call_op
+ */
static void nlmsvc_grant_release(void *data)
{
struct nlm_rqst *call = data;
-
- lock_kernel();
nlmsvc_release_block(call->a_block);
- unlock_kernel();
}

static const struct rpc_call_ops nlmsvc_grant_ops = {
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index 0f2ab74..c3069f3 100644
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -260,9 +260,7 @@ static void nlmsvc_callback_exit(struct rpc_task *task, void *data)

static void nlmsvc_callback_release(void *data)
{
- lock_kernel();
nlm_release_call(data);
- unlock_kernel();
}

static const struct rpc_call_ops nlmsvc_callback_ops = {


2010-09-22 15:49:40

by Trond Myklebust

[permalink] [raw]
Subject: Re: [PATCH 2/2] lockd: Mostly remove BKL from the server

On Wed, 2010-09-22 at 11:43 -0400, Bryan Schumaker wrote:
> On 09/22/2010 11:37 AM, J. Bruce Fields wrote:
> > On Tue, Sep 21, 2010 at 04:38:12PM -0400, Bryan Schumaker wrote:
> >> lockd: Mostly remove BKL from the server
> >>
> >> This patch removes all but one call to lock_kernel() from the server.
> >
> > Thanks. Does this need to go in any particular order with respect to
> > the other BKL patches, or should I just apply this whenever?
> >
> > --b.
>
> It doesn't use lock_flocks(), so you should be able to apply it whenever.

Note that a patch defining lock_flocks() in terms of the BKL went into
Linus' tree last night, so we no longer have to worry about that
dependency.

Cheers
Trond


2010-09-22 19:16:28

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH 2/2] lockd: Mostly remove BKL from the server

On Tue, Sep 21, 2010 at 04:38:12PM -0400, Bryan Schumaker wrote:
> lockd: Mostly remove BKL from the server

I wish I had better file-locking tests: testing of cross-node gfs2
conflicts would be especially useful. This all looks right, though.
Applying.

--b.

>
> This patch removes all but one call to lock_kernel() from the server.
>
> Signed-off-by: Bryan Schumaker <[email protected]>
> ---
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 031c656..a336e83 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -230,9 +230,7 @@ static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlm4svc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlm4svc_callback_ops = {
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index 84055d3..6f1ef00 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -52,12 +52,13 @@ static const struct rpc_call_ops nlmsvc_grant_ops;
> * The list of blocked locks to retry
> */
> static LIST_HEAD(nlm_blocked);
> +static DEFINE_SPINLOCK(nlm_blocked_lock);
>
> /*
> * Insert a blocked lock into the global list
> */
> static void
> -nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when)
> {
> struct nlm_block *b;
> struct list_head *pos;
> @@ -87,6 +88,13 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> block->b_when = when;
> }
>
> +static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +{
> + spin_lock(&nlm_blocked_lock);
> + nlmsvc_insert_block_locked(block, when);
> + spin_unlock(&nlm_blocked_lock);
> +}
> +
> /*
> * Remove a block from the global list
> */
> @@ -94,7 +102,9 @@ static inline void
> nlmsvc_remove_block(struct nlm_block *block)
> {
> if (!list_empty(&block->b_list)) {
> + spin_lock(&nlm_blocked_lock);
> list_del_init(&block->b_list);
> + spin_unlock(&nlm_blocked_lock);
> nlmsvc_release_block(block);
> }
> }
> @@ -651,7 +661,7 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> struct nlm_block *block;
> int rc = -ENOENT;
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> list_for_each_entry(block, &nlm_blocked, b_list) {
> if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
> dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
> @@ -665,13 +675,13 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> } else if (result == 0)
> block->b_granted = 1;
>
> - nlmsvc_insert_block(block, 0);
> + nlmsvc_insert_block_locked(block, 0);
> svc_wake_up(block->b_daemon);
> rc = 0;
> break;
> }
> }
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> if (rc == -ENOENT)
> printk(KERN_WARNING "lockd: grant for unknown block\n");
> return rc;
> @@ -803,7 +813,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
>
> dprintk("lockd: GRANT_MSG RPC callback\n");
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> /* if the block is not on a list at this point then it has
> * been invalidated. Don't try to requeue it.
> *
> @@ -825,19 +835,20 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
> /* Call was successful, now wait for client callback */
> timeout = 60 * HZ;
> }
> - nlmsvc_insert_block(block, timeout);
> + nlmsvc_insert_block_locked(block, timeout);
> svc_wake_up(block->b_daemon);
> out:
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> }
>
> +/*
> + * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an
> + * .rpc_release rpc_call_op
> + */
> static void nlmsvc_grant_release(void *data)
> {
> struct nlm_rqst *call = data;
> -
> - lock_kernel();
> nlmsvc_release_block(call->a_block);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_grant_ops = {
> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index 0f2ab74..c3069f3 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -260,9 +260,7 @@ static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlmsvc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_callback_ops = {

2010-09-22 15:38:31

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH 2/2] lockd: Mostly remove BKL from the server

On Tue, Sep 21, 2010 at 04:38:12PM -0400, Bryan Schumaker wrote:
> lockd: Mostly remove BKL from the server
>
> This patch removes all but one call to lock_kernel() from the server.

Thanks. Does this need to go in any particular order with respect to
the other BKL patches, or should I just apply this whenever?

--b.

>
> Signed-off-by: Bryan Schumaker <[email protected]>
> ---
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 031c656..a336e83 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -230,9 +230,7 @@ static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlm4svc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlm4svc_callback_ops = {
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index 84055d3..6f1ef00 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -52,12 +52,13 @@ static const struct rpc_call_ops nlmsvc_grant_ops;
> * The list of blocked locks to retry
> */
> static LIST_HEAD(nlm_blocked);
> +static DEFINE_SPINLOCK(nlm_blocked_lock);
>
> /*
> * Insert a blocked lock into the global list
> */
> static void
> -nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when)
> {
> struct nlm_block *b;
> struct list_head *pos;
> @@ -87,6 +88,13 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> block->b_when = when;
> }
>
> +static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +{
> + spin_lock(&nlm_blocked_lock);
> + nlmsvc_insert_block_locked(block, when);
> + spin_unlock(&nlm_blocked_lock);
> +}
> +
> /*
> * Remove a block from the global list
> */
> @@ -94,7 +102,9 @@ static inline void
> nlmsvc_remove_block(struct nlm_block *block)
> {
> if (!list_empty(&block->b_list)) {
> + spin_lock(&nlm_blocked_lock);
> list_del_init(&block->b_list);
> + spin_unlock(&nlm_blocked_lock);
> nlmsvc_release_block(block);
> }
> }
> @@ -651,7 +661,7 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> struct nlm_block *block;
> int rc = -ENOENT;
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> list_for_each_entry(block, &nlm_blocked, b_list) {
> if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
> dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
> @@ -665,13 +675,13 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> } else if (result == 0)
> block->b_granted = 1;
>
> - nlmsvc_insert_block(block, 0);
> + nlmsvc_insert_block_locked(block, 0);
> svc_wake_up(block->b_daemon);
> rc = 0;
> break;
> }
> }
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> if (rc == -ENOENT)
> printk(KERN_WARNING "lockd: grant for unknown block\n");
> return rc;
> @@ -803,7 +813,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
>
> dprintk("lockd: GRANT_MSG RPC callback\n");
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> /* if the block is not on a list at this point then it has
> * been invalidated. Don't try to requeue it.
> *
> @@ -825,19 +835,20 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
> /* Call was successful, now wait for client callback */
> timeout = 60 * HZ;
> }
> - nlmsvc_insert_block(block, timeout);
> + nlmsvc_insert_block_locked(block, timeout);
> svc_wake_up(block->b_daemon);
> out:
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> }
>
> +/*
> + * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an
> + * .rpc_release rpc_call_op
> + */
> static void nlmsvc_grant_release(void *data)
> {
> struct nlm_rqst *call = data;
> -
> - lock_kernel();
> nlmsvc_release_block(call->a_block);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_grant_ops = {
> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index 0f2ab74..c3069f3 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -260,9 +260,7 @@ static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlmsvc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_callback_ops = {
> --
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2010-09-22 15:43:18

by Anna Schumaker

[permalink] [raw]
Subject: Re: [PATCH 2/2] lockd: Mostly remove BKL from the server

On 09/22/2010 11:37 AM, J. Bruce Fields wrote:
> On Tue, Sep 21, 2010 at 04:38:12PM -0400, Bryan Schumaker wrote:
>> lockd: Mostly remove BKL from the server
>>
>> This patch removes all but one call to lock_kernel() from the server.
>
> Thanks. Does this need to go in any particular order with respect to
> the other BKL patches, or should I just apply this whenever?
>
> --b.

It doesn't use lock_flocks(), so you should be able to apply it whenever.

-Bryan