diff mbox series

[v2,34/47] nfsd: dynamically allocate the nfsd-client shrinker

Message ID 20230724094354.90817-35-zhengqi.arch@bytedance.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series use refcount+RCU method to implement lockless slab shrink | expand

Commit Message

Qi Zheng July 24, 2023, 9:43 a.m. UTC 
In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the nfsd-client shrinker, so that it can be freed
asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU
read-side critical section when releasing the struct nfsd_net.

Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
 fs/nfsd/netns.h     |  2 +-
 fs/nfsd/nfs4state.c | 20 ++++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

Comments

Jeff Layton July 24, 2023, 12:17 p.m. UTC | #1 
On Mon, 2023-07-24 at 17:43 +0800, Qi Zheng wrote:
> In preparation for implementing lockless slab shrink, use new APIs to
> dynamically allocate the nfsd-client shrinker, so that it can be freed
> asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU
> read-side critical section when releasing the struct nfsd_net.
> 
> Acked-by: Chuck Lever <chuck.lever@oracle.com>
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
> ---
>  fs/nfsd/netns.h     |  2 +-
>  fs/nfsd/nfs4state.c | 20 ++++++++++++--------
>  2 files changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> index ec49b200b797..f669444d5336 100644
> --- a/fs/nfsd/netns.h
> +++ b/fs/nfsd/netns.h
> @@ -195,7 +195,7 @@ struct nfsd_net {
>  	int			nfs4_max_clients;
>  
>  	atomic_t		nfsd_courtesy_clients;
> -	struct shrinker		nfsd_client_shrinker;
> +	struct shrinker		*nfsd_client_shrinker;
>  	struct work_struct	nfsd_shrinker_work;
>  };
>  
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 3339177f8e2f..c7a4616cd866 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4388,8 +4388,7 @@ static unsigned long
>  nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
>  {
>  	int count;
> -	struct nfsd_net *nn = container_of(shrink,
> -			struct nfsd_net, nfsd_client_shrinker);
> +	struct nfsd_net *nn = shrink->private_data;
>  
>  	count = atomic_read(&nn->nfsd_courtesy_clients);
>  	if (!count)
> @@ -8125,12 +8124,17 @@ static int nfs4_state_create_net(struct net *net)
>  	INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker);
>  	get_net(net);
>  
> -	nn->nfsd_client_shrinker.scan_objects = nfsd4_state_shrinker_scan;
> -	nn->nfsd_client_shrinker.count_objects = nfsd4_state_shrinker_count;
> -	nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS;
> -
> -	if (register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client"))
> +	nn->nfsd_client_shrinker = shrinker_alloc(0, "nfsd-client");
> +	if (!nn->nfsd_client_shrinker)
>  		goto err_shrinker;
> +
> +	nn->nfsd_client_shrinker->scan_objects = nfsd4_state_shrinker_scan;
> +	nn->nfsd_client_shrinker->count_objects = nfsd4_state_shrinker_count;
> +	nn->nfsd_client_shrinker->seeks = DEFAULT_SEEKS;
> +	nn->nfsd_client_shrinker->private_data = nn;
> +
> +	shrinker_register(nn->nfsd_client_shrinker);
> +
>  	return 0;
>  
>  err_shrinker:
> @@ -8228,7 +8232,7 @@ nfs4_state_shutdown_net(struct net *net)
>  	struct list_head *pos, *next, reaplist;
>  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
>  
> -	unregister_shrinker(&nn->nfsd_client_shrinker);
> +	shrinker_unregister(nn->nfsd_client_shrinker);
>  	cancel_work(&nn->nfsd_shrinker_work);
>  	cancel_delayed_work_sync(&nn->laundromat_work);
>  	locks_end_grace(&nn->nfsd4_manager);

Acked-by: Jeff Layton <jlayton@kernel.org>
diff mbox series

Patch

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index ec49b200b797..f669444d5336 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -195,7 +195,7 @@  struct nfsd_net {
 	int			nfs4_max_clients;
 
 	atomic_t		nfsd_courtesy_clients;
-	struct shrinker		nfsd_client_shrinker;
+	struct shrinker		*nfsd_client_shrinker;
 	struct work_struct	nfsd_shrinker_work;
 };
 
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3339177f8e2f..c7a4616cd866 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4388,8 +4388,7 @@  static unsigned long
 nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
 {
 	int count;
-	struct nfsd_net *nn = container_of(shrink,
-			struct nfsd_net, nfsd_client_shrinker);
+	struct nfsd_net *nn = shrink->private_data;
 
 	count = atomic_read(&nn->nfsd_courtesy_clients);
 	if (!count)
@@ -8125,12 +8124,17 @@  static int nfs4_state_create_net(struct net *net)
 	INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker);
 	get_net(net);
 
-	nn->nfsd_client_shrinker.scan_objects = nfsd4_state_shrinker_scan;
-	nn->nfsd_client_shrinker.count_objects = nfsd4_state_shrinker_count;
-	nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS;
-
-	if (register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client"))
+	nn->nfsd_client_shrinker = shrinker_alloc(0, "nfsd-client");
+	if (!nn->nfsd_client_shrinker)
 		goto err_shrinker;
+
+	nn->nfsd_client_shrinker->scan_objects = nfsd4_state_shrinker_scan;
+	nn->nfsd_client_shrinker->count_objects = nfsd4_state_shrinker_count;
+	nn->nfsd_client_shrinker->seeks = DEFAULT_SEEKS;
+	nn->nfsd_client_shrinker->private_data = nn;
+
+	shrinker_register(nn->nfsd_client_shrinker);
+
 	return 0;
 
 err_shrinker:
@@ -8228,7 +8232,7 @@  nfs4_state_shutdown_net(struct net *net)
 	struct list_head *pos, *next, reaplist;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	unregister_shrinker(&nn->nfsd_client_shrinker);
+	shrinker_unregister(nn->nfsd_client_shrinker);
 	cancel_work(&nn->nfsd_shrinker_work);
 	cancel_delayed_work_sync(&nn->laundromat_work);
 	locks_end_grace(&nn->nfsd4_manager);