SUNRPC: Lockless lookup of RPCSEC_GSS mechanisms

Use RCU protected lookups for discovering the supported mechanisms.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2018-09-29 15:14:47 -04:00
parent 4e4c3bef44
commit 0c1c19f46e

View file

@ -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;
}