SUNRPC: remove machine_cred field from struct auth_cred

The cred is a machine_cred iff ->principal is set, so there is no
need for the extra flag.

There is one case which deserves some
explanation. nfs4_root_machine_cred() calls rpc_lookup_machine_cred()
with a NULL principal name which results in not getting a machine
credential, but getting a root credential instead.
This appears to be what is expected of the caller, and is
clearly the result provided by both auth_unix and auth_gss
which already ignore the flag.

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

3 files changed, 8 insertions, 12 deletions

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 831ea65bd9f4..1c0468f39479 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -46,9 +46,8 @@ enum {
 
 struct auth_cred {
         const struct cred *cred;
-        const char *principal;
+        const char *principal;  /* If present, this is a machine credential */
         unsigned long ac_flags;
-        unsigned char machine_cred : 1;
 };
 
 /*
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index 6c7c65da6063..7d1a8f45726c 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -50,12 +50,13 @@ EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);
 
 /*
  * Public call interface for looking up machine creds.
+ * Note that if service_name is NULL, we actually look up
+ * "root" credential.
  */
 struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
 {
         struct auth_cred acred = {
                 .principal = service_name,
-                .machine_cred = 1,
                 .cred = get_task_cred(&init_task),
         };
         struct rpc_cred *ret;
@@ -108,11 +109,10 @@ generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, g
 
         gcred->acred.cred = gcred->gc_base.cr_cred;
         gcred->acred.ac_flags = 0;
-        gcred->acred.machine_cred = acred->machine_cred;
         gcred->acred.principal = acred->principal;
 
         dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
-                        gcred->acred.machine_cred ? "machine" : "generic",
+                        gcred->acred.principal ? "machine" : "generic",
                         gcred,
                         from_kuid(&init_user_ns, acred->cred->fsuid),
                         from_kgid(&init_user_ns, acred->cred->fsgid));
@@ -145,7 +145,7 @@ generic_destroy_cred(struct rpc_cred *cred)
 static int
 machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags)
 {
-        if (!gcred->acred.machine_cred ||
+        if (!gcred->acred.principal ||
             gcred->acred.principal != acred->principal ||
             !uid_eq(gcred->acred.cred->fsuid, acred->cred->fsuid) ||
             !gid_eq(gcred->acred.cred->fsgid, acred->cred->fsgid))
@@ -163,12 +163,12 @@ generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
         int i;
         struct group_info *a, *g;
 
-        if (acred->machine_cred)
+        if (acred->principal)
                 return machine_cred_match(acred, gcred, flags);
 
         if (!uid_eq(gcred->acred.cred->fsuid, acred->cred->fsuid) ||
             !gid_eq(gcred->acred.cred->fsgid, acred->cred->fsgid) ||
-            gcred->acred.machine_cred != 0)
+            gcred->acred.principal != NULL)
                 goto out_nomatch;
 
         a = acred->cred->group_info;
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 762b071cba71..b218e15b61cb 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1395,9 +1395,7 @@ gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t
          */
         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
         cred->gc_service = gss_auth->service;
-        cred->gc_principal = NULL;
-        if (acred->machine_cred)
-                cred->gc_principal = acred->principal;
+        cred->gc_principal = acred->principal;
         kref_get(&gss_auth->kref);
         return &cred->gc_base;
 
@@ -1610,7 +1608,6 @@ static int gss_renew_cred(struct rpc_task *task)
         struct auth_cred acred = {
                 .cred = oldcred->cr_cred,
                 .principal = gss_cred->gc_principal,
-                .machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
         };
         struct rpc_cred *new;