[08/15] NFS: Lockless DNS lookups
diff mbox series

Message ID 20181001144157.3515-9-trond.myklebust@hammerspace.com
State New
Headers show
Series
  • Performance improvements for knfsd
Related show

Commit Message

Trond Myklebust Oct. 1, 2018, 2:41 p.m. UTC
Enable RCU protected lookup in the legacy DNS resolver.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dns_resolve.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Comments

J. Bruce Fields Oct. 3, 2018, 4:10 p.m. UTC | #1
The individual conversions of these caches looks straightforward to me.
Thanks for doing this in these small steps.  I'm assuming you're OK with
these nfs/ changes going through the nfsd tree.

--b.

On Mon, Oct 01, 2018 at 10:41:50AM -0400, Trond Myklebust wrote:
> Enable RCU protected lookup in the legacy DNS resolver.
> 
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
>  fs/nfs/dns_resolve.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
> index 060c658eab66..e93a5dc07c8c 100644
> --- a/fs/nfs/dns_resolve.c
> +++ b/fs/nfs/dns_resolve.c
> @@ -65,6 +65,7 @@ struct nfs_dns_ent {
>  
>  	struct sockaddr_storage addr;
>  	size_t addrlen;
> +	struct rcu_head rcu_head;
>  };
>  
>  
> @@ -101,15 +102,23 @@ static void nfs_dns_ent_init(struct cache_head *cnew,
>  	}
>  }
>  
> -static void nfs_dns_ent_put(struct kref *ref)
> +static void nfs_dns_ent_free_rcu(struct rcu_head *head)
>  {
>  	struct nfs_dns_ent *item;
>  
> -	item = container_of(ref, struct nfs_dns_ent, h.ref);
> +	item = container_of(head, struct nfs_dns_ent, rcu_head);
>  	kfree(item->hostname);
>  	kfree(item);
>  }
>  
> +static void nfs_dns_ent_put(struct kref *ref)
> +{
> +	struct nfs_dns_ent *item;
> +
> +	item = container_of(ref, struct nfs_dns_ent, h.ref);
> +	call_rcu(item, nfs_dns_ent_free_rcu);
> +}
> +
>  static struct cache_head *nfs_dns_ent_alloc(void)
>  {
>  	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);
> @@ -195,7 +204,7 @@ static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd,
>  {
>  	struct cache_head *ch;
>  
> -	ch = sunrpc_cache_lookup(cd,
> +	ch = sunrpc_cache_lookup_rcu(cd,
>  			&key->h,
>  			nfs_dns_hash(key));
>  	if (!ch)
> -- 
> 2.17.1
Trond Myklebust Oct. 3, 2018, 5:55 p.m. UTC | #2
On Wed, 2018-10-03 at 12:10 -0400, J . Bruce Fields wrote:
> The individual conversions of these caches looks straightforward to
> me.
> Thanks for doing this in these small steps.  I'm assuming you're OK
> with
> these nfs/ changes going through the nfsd tree.
> 

Yes please. With the bulk of the changes being nfsd specific, that
makes more sense to me.

> --b.
> 
> On Mon, Oct 01, 2018 at 10:41:50AM -0400, Trond Myklebust wrote:
> > Enable RCU protected lookup in the legacy DNS resolver.
> > 
> > Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> > ---
> >  fs/nfs/dns_resolve.c | 15 ++++++++++++---
> >  1 file changed, 12 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
> > index 060c658eab66..e93a5dc07c8c 100644
> > --- a/fs/nfs/dns_resolve.c
> > +++ b/fs/nfs/dns_resolve.c
> > @@ -65,6 +65,7 @@ struct nfs_dns_ent {
> >  
> >  	struct sockaddr_storage addr;
> >  	size_t addrlen;
> > +	struct rcu_head rcu_head;
> >  };
> >  
> >  
> > @@ -101,15 +102,23 @@ static void nfs_dns_ent_init(struct
> > cache_head *cnew,
> >  	}
> >  }
> >  
> > -static void nfs_dns_ent_put(struct kref *ref)
> > +static void nfs_dns_ent_free_rcu(struct rcu_head *head)
> >  {
> >  	struct nfs_dns_ent *item;
> >  
> > -	item = container_of(ref, struct nfs_dns_ent, h.ref);
> > +	item = container_of(head, struct nfs_dns_ent, rcu_head);
> >  	kfree(item->hostname);
> >  	kfree(item);
> >  }
> >  
> > +static void nfs_dns_ent_put(struct kref *ref)
> > +{
> > +	struct nfs_dns_ent *item;
> > +
> > +	item = container_of(ref, struct nfs_dns_ent, h.ref);
> > +	call_rcu(item, nfs_dns_ent_free_rcu);
> > +}
> > +
> >  static struct cache_head *nfs_dns_ent_alloc(void)
> >  {
> >  	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);
> > @@ -195,7 +204,7 @@ static struct nfs_dns_ent
> > *nfs_dns_lookup(struct cache_detail *cd,
> >  {
> >  	struct cache_head *ch;
> >  
> > -	ch = sunrpc_cache_lookup(cd,
> > +	ch = sunrpc_cache_lookup_rcu(cd,
> >  			&key->h,
> >  			nfs_dns_hash(key));
> >  	if (!ch)
> > -- 
> > 2.17.1

Patch
diff mbox series

diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
index 060c658eab66..e93a5dc07c8c 100644
--- a/fs/nfs/dns_resolve.c
+++ b/fs/nfs/dns_resolve.c
@@ -65,6 +65,7 @@  struct nfs_dns_ent {
 
 	struct sockaddr_storage addr;
 	size_t addrlen;
+	struct rcu_head rcu_head;
 };
 
 
@@ -101,15 +102,23 @@  static void nfs_dns_ent_init(struct cache_head *cnew,
 	}
 }
 
-static void nfs_dns_ent_put(struct kref *ref)
+static void nfs_dns_ent_free_rcu(struct rcu_head *head)
 {
 	struct nfs_dns_ent *item;
 
-	item = container_of(ref, struct nfs_dns_ent, h.ref);
+	item = container_of(head, struct nfs_dns_ent, rcu_head);
 	kfree(item->hostname);
 	kfree(item);
 }
 
+static void nfs_dns_ent_put(struct kref *ref)
+{
+	struct nfs_dns_ent *item;
+
+	item = container_of(ref, struct nfs_dns_ent, h.ref);
+	call_rcu(item, nfs_dns_ent_free_rcu);
+}
+
 static struct cache_head *nfs_dns_ent_alloc(void)
 {
 	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);
@@ -195,7 +204,7 @@  static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd,
 {
 	struct cache_head *ch;
 
-	ch = sunrpc_cache_lookup(cd,
+	ch = sunrpc_cache_lookup_rcu(cd,
 			&key->h,
 			nfs_dns_hash(key));
 	if (!ch)