Commit 437f9145 authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

NFS: Lockless DNS lookups 



Enable RCU protected lookup in the legacy DNS resolver.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 9d5afd94

fs/nfs/dns_resolve.c

+12 −3
Original line number Diff line number Diff line
@@ -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)