SUNRPC: add 'struct cred *' to auth_cred and rpc_cred

The SUNRPC credential framework was put together before
Linux has 'struct cred'.  Now that we have it, it makes sense to
use it.
This first step just includes a suitable 'struct cred *' pointer
in every 'struct auth_cred' and almost every 'struct rpc_cred'.

The rpc_cred used for auth_null has a NULL 'struct cred *' as nothing
else really makes sense.

For rpc_cred, the pointer is reference counted.
For auth_cred it isn't.  struct auth_cred are either allocated on
the stack, in which case the thread owns a reference to the auth,
or are part of 'struct generic_cred' in which case gc_base owns the
reference, and "acred" shares it.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

4 files changed, 17 insertions, 2 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index ad8ead738981..a7e08e44f92b 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -659,6 +659,7 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags)
         acred.uid = cred->fsuid;
         acred.gid = cred->fsgid;
         acred.group_info = cred->group_info;
+        acred.cred = cred;
         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
         return ret;
 }
@@ -674,6 +675,7 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
         cred->cr_auth = auth;
         cred->cr_ops = ops;
         cred->cr_expire = jiffies;
+        cred->cr_cred = get_cred(acred->cred);
         cred->cr_uid = acred->uid;
 }
 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
@@ -694,11 +696,15 @@ rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
         struct auth_cred acred = {
                 .uid = GLOBAL_ROOT_UID,
                 .gid = GLOBAL_ROOT_GID,
+                .cred = get_task_cred(&init_task),
         };
+        struct rpc_cred *ret;
 
         dprintk("RPC: %5u looking up %s cred\n",
                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
-        return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
+        ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
+        put_cred(acred.cred);
+        return ret;
 }
 
 static struct rpc_cred *
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index ab4a3be1542a..16a0a4b89bb4 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -61,11 +61,15 @@ struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
                 .gid = RPC_MACHINE_CRED_GROUPID,
                 .principal = service_name,
                 .machine_cred = 1,
+                .cred = get_task_cred(&init_task),
         };
+        struct rpc_cred *ret;
 
         dprintk("RPC:       looking up machine cred for service %s\n",
                         service_name);
-        return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
+        ret = generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
+        put_cred(acred.cred);
+        return ret;
 }
 EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
 
@@ -110,6 +114,7 @@ generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, g
         gcred->acred.uid = acred->uid;
         gcred->acred.gid = acred->gid;
         gcred->acred.group_info = acred->group_info;
+        gcred->acred.cred = gcred->gc_base.cr_cred;
         gcred->acred.ac_flags = 0;
         if (gcred->acred.group_info != NULL)
                 get_group_info(gcred->acred.group_info);
@@ -132,6 +137,7 @@ generic_free_cred(struct rpc_cred *cred)
         dprintk("RPC:       generic_free_cred %p\n", gcred);
         if (gcred->acred.group_info != NULL)
                 put_group_info(gcred->acred.group_info);
+        put_cred(cred->cr_cred);
         kfree(gcred);
 }
 
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index ba765473d1f0..56604b259f2c 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1343,6 +1343,7 @@ gss_destroy_nullcred(struct rpc_cred *cred)
         struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
 
         RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
+        put_cred(cred->cr_cred);
         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
         if (ctx)
                 gss_put_ctx(ctx);
@@ -1608,6 +1609,7 @@ static int gss_renew_cred(struct rpc_task *task)
         struct rpc_auth *auth = oldcred->cr_auth;
         struct auth_cred acred = {
                 .uid = oldcred->cr_uid,
+                .cred = oldcred->cr_cred,
                 .principal = gss_cred->gc_principal,
                 .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
         };
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index 4c1c7e56288f..36e01384f082 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -97,6 +97,7 @@ static void
 unx_free_cred(struct unx_cred *unx_cred)
 {
         dprintk("RPC:       unx_free_cred %p\n", unx_cred);
+        put_cred(unx_cred->uc_base.cr_cred);
         kfree(unx_cred);
 }