Commit 608a0ab2 authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

SUNRPC: Add lockless lookup of the server's auth domain 



Avoid taking the global auth_domain_lock in most lookups of the auth domain
by adding an RCU protected lookup.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 30382d6c

include/linux/sunrpc/svcauth.h

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ struct auth_domain { 
	struct hlist_node	hash;

	char			*name;

	struct auth_ops		*flavour;

	struct rcu_head		rcu_head;

};



/*

net/sunrpc/auth_gss/svcauth_gss.c

+8 −1
Original line number Diff line number Diff line
@@ -1764,14 +1764,21 @@ out_err: 
}



static void

svcauth_gss_domain_release(struct auth_domain *dom)

svcauth_gss_domain_release_rcu(struct rcu_head *head)

{

	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);

	struct gss_domain *gd = container_of(dom, struct gss_domain, h);



	kfree(dom->name);

	kfree(gd);

}



static void

svcauth_gss_domain_release(struct auth_domain *dom)

{

	call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu);

}



static struct auth_ops svcauthops_gss = {

	.name		= "rpcsec_gss",

	.owner		= THIS_MODULE,

net/sunrpc/svcauth.c

+19 −3
Original line number Diff line number Diff line
@@ -143,10 +143,11 @@ static struct hlist_head auth_domain_table[DN_HASHMAX]; 
static DEFINE_SPINLOCK(auth_domain_lock);



static void auth_domain_release(struct kref *kref)

	__releases(&auth_domain_lock)

{

	struct auth_domain *dom = container_of(kref, struct auth_domain, ref);



	hlist_del(&dom->hash);

	hlist_del_rcu(&dom->hash);

	dom->flavour->domain_release(dom);

	spin_unlock(&auth_domain_lock);

}
@@ -175,7 +176,7 @@ auth_domain_lookup(char *name, struct auth_domain *new) 
		}

	}

	if (new)

		hlist_add_head(&new->hash, head);

		hlist_add_head_rcu(&new->hash, head);

	spin_unlock(&auth_domain_lock);

	return new;

}
@@ -183,6 +184,21 @@ EXPORT_SYMBOL_GPL(auth_domain_lookup); 


struct auth_domain *auth_domain_find(char *name)

{

	return auth_domain_lookup(name, NULL);

	struct auth_domain *hp;

	struct hlist_head *head;



	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];



	rcu_read_lock();

	hlist_for_each_entry_rcu(hp, head, hash) {

		if (strcmp(hp->name, name)==0) {

			if (!kref_get_unless_zero(&hp->ref))

				hp = NULL;

			rcu_read_unlock();

			return hp;

		}

	}

	rcu_read_unlock();

	return NULL;

}

EXPORT_SYMBOL_GPL(auth_domain_find);

net/sunrpc/svcauth_unix.c

+8 −2
Original line number Diff line number Diff line
@@ -37,20 +37,26 @@ struct unix_domain { 
extern struct auth_ops svcauth_null;

extern struct auth_ops svcauth_unix;



static void svcauth_unix_domain_release(struct auth_domain *dom)

static void svcauth_unix_domain_release_rcu(struct rcu_head *head)

{

	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);

	struct unix_domain *ud = container_of(dom, struct unix_domain, h);



	kfree(dom->name);

	kfree(ud);

}



static void svcauth_unix_domain_release(struct auth_domain *dom)

{

	call_rcu(&dom->rcu_head, svcauth_unix_domain_release_rcu);

}



struct auth_domain *unix_domain_find(char *name)

{

	struct auth_domain *rv;

	struct unix_domain *new = NULL;



	rv = auth_domain_lookup(name, NULL);

	rv = auth_domain_find(name);

	while(1) {

		if (rv) {

			if (new && rv != &new->h)

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