Commit 0c1c19f4 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Lockless lookup of RPCSEC_GSS mechanisms 



Use RCU protected lookups for discovering the supported mechanisms.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 4e4c3bef

net/sunrpc/auth_gss/gss_mech_switch.c

+14 −14
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ int gss_mech_register(struct gss_api_mech *gm) 
	if (status)

		return status;

	spin_lock(&registered_mechs_lock);

	list_add(&gm->gm_list, &registered_mechs);

	list_add_rcu(&gm->gm_list, &registered_mechs);

	spin_unlock(&registered_mechs_lock);

	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);

	return 0;
@@ -132,7 +132,7 @@ EXPORT_SYMBOL_GPL(gss_mech_register); 
void gss_mech_unregister(struct gss_api_mech *gm)

{

	spin_lock(&registered_mechs_lock);

	list_del(&gm->gm_list);

	list_del_rcu(&gm->gm_list);

	spin_unlock(&registered_mechs_lock);

	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);

	gss_mech_free(gm);
@@ -151,15 +151,15 @@ _gss_mech_get_by_name(const char *name) 
{

	struct gss_api_mech	*pos, *gm = NULL;



	spin_lock(&registered_mechs_lock);

	list_for_each_entry(pos, &registered_mechs, gm_list) {

	rcu_read_lock();

	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {

		if (0 == strcmp(name, pos->gm_name)) {

			if (try_module_get(pos->gm_owner))

				gm = pos;

			break;

		}

	}

	spin_unlock(&registered_mechs_lock);

	rcu_read_unlock();

	return gm;



}
@@ -186,8 +186,8 @@ struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj) 
	dprintk("RPC:       %s(%s)\n", __func__, buf);

	request_module("rpc-auth-gss-%s", buf);



	spin_lock(&registered_mechs_lock);

	list_for_each_entry(pos, &registered_mechs, gm_list) {

	rcu_read_lock();

	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {

		if (obj->len == pos->gm_oid.len) {

			if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {

				if (try_module_get(pos->gm_owner))
@@ -196,7 +196,7 @@ struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj) 
			}

		}

	}

	spin_unlock(&registered_mechs_lock);

	rcu_read_unlock();

	return gm;

}
@@ -216,15 +216,15 @@ static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor) 
{

	struct gss_api_mech *gm = NULL, *pos;



	spin_lock(&registered_mechs_lock);

	list_for_each_entry(pos, &registered_mechs, gm_list) {

	rcu_read_lock();

	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {

		if (!mech_supports_pseudoflavor(pos, pseudoflavor))

			continue;

		if (try_module_get(pos->gm_owner))

			gm = pos;

		break;

	}

	spin_unlock(&registered_mechs_lock);

	rcu_read_unlock();

	return gm;

}
@@ -257,8 +257,8 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size) 
	struct gss_api_mech *pos = NULL;

	int j, i = 0;



	spin_lock(&registered_mechs_lock);

	list_for_each_entry(pos, &registered_mechs, gm_list) {

	rcu_read_lock();

	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {

		for (j = 0; j < pos->gm_pf_num; j++) {

			if (i >= size) {

				spin_unlock(&registered_mechs_lock);
@@ -267,7 +267,7 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size) 
			array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;

		}

	}

	spin_unlock(&registered_mechs_lock);

	rcu_read_unlock();

	return i;

}