libnetfs: protid and peropen return error_t's

[James A Morrison]

 Hi,

 This patch should sync the interfaces of libnetfs and libdiskfs wrt
the creation of peropens and protids.

2002-04-05  James A. Morrison  <ja2morri@uwaterloo.ca>

libnetfs:
        netfs_make_peropen, and netfs_make_protid to return an error_t and
        take an extra parameter to replace the old return value.
        Removed old netfs_make_user function signature.

        * make-peropen.c (netfs_make_peropen): Instead of returning the
        peropen, return an error_t and set the peropen in the new
        parameter *PPO.
        * make-protid.c (netfs_make_protid): Instead of returning the protid,
        return an error_t and set the protid in the new parameter *PI.

        * dir-lookup.c (netfs_S_dir_lookup): Check the return values of
        netfs_make_peropen netfs_make_protid using the new semantics.
        * dir-mkfile.c (netfs_S_dir_mkfile): Likewise.
        * file-reparent.c (netfs_S_file_reparent): Likewise
        * file-exec.c (netfs_S_file_exec): Likewise
        * io-duplicate.c (netfs_S_io_duplicate): Likewise.
        * io-reauthenticate.c (netfs_S_io_reauthenticate): Likewise.
        * io-restrict-auth.c (netfs_S_io_restrict_auth): Likewise.
        * trans-callback.c (_netfs_translator_callback2_fn): Likewise.
        * fsys-getroot.c (netfs_S_fsys_getroot): Likwise.  Removed superflous
        error state check.      

Index: libnetfs/dir-lookup.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/dir-lookup.c,v
retrieving revision 1.22
diff -u -p -r1.22 dir-lookup.c
--- libnetfs/dir-lookup.c       9 Sep 2001 17:32:03 -0000       1.22
+++ libnetfs/dir-lookup.c       7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1995,96,97,98,99,2000,01 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,97,98,99,2000,01,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -47,6 +47,7 @@ netfs_S_dir_lookup (struct protid *dirus
   struct node *dnp, *np;
   char *nextname;
   error_t error;
+  struct peropen *newpo;
   struct protid *newpi;
   struct iouser *user;
 
@@ -239,14 +240,18 @@ netfs_S_dir_lookup (struct protid *dirus
          error = iohelp_create_empty_iouser (&user);
          if (! error)
            {
-             newpi = netfs_make_protid (netfs_make_peropen (dnp, 0,
-                                                            diruser->po),
-                                        user);
-             if (! newpi)
-               {
-                 error = errno;
-                 iohelp_free_iouser (user);
+             error = netfs_make_peropen (dnp, 0, diruser->po, &newpo);
+             if (! error)
+               {
+                 error = netfs_make_protid (newpo, user, &newpi);
+                 if (error)
+                   {
+                     netfs_release_peropen (newpo);
+                     iohelp_free_iouser (user);
+                   }
                }
+             else
+               iohelp_free_iouser (user);
            }
 
          if (! error)
@@ -381,12 +386,17 @@ netfs_S_dir_lookup (struct protid *dirus
   if (error)
     goto out;
 
-  newpi = netfs_make_protid (netfs_make_peropen (np, flags, diruser->po),
-                            user);
-  if (! newpi)
+  error = netfs_make_peropen (np, flags, diruser->po, &newpo);
+  if (! error)
+    {
+      error = netfs_make_protid (newpo, user, &newpi);
+      if (error)
+       netfs_release_peropen (newpo);
+    }
+
+  if (error)
     {
       iohelp_free_iouser (user);
-      error = errno;
       goto out;
     }
 
Index: libnetfs/dir-mkfile.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/dir-mkfile.c,v
retrieving revision 1.8
diff -u -p -r1.8 dir-mkfile.c
--- libnetfs/dir-mkfile.c       9 Sep 2001 17:32:03 -0000       1.8
+++ libnetfs/dir-mkfile.c       7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995,96,97,2001 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,97,2001,2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -29,6 +29,7 @@ netfs_S_dir_mkfile (struct protid *dirus
   error_t err;
   struct node *np;
   struct iouser *user;
+  struct peropen *newpo;
   struct protid *newpi;
 
   mutex_lock (&diruser->po->np->lock);
@@ -41,20 +42,22 @@ netfs_S_dir_mkfile (struct protid *dirus
       err = iohelp_dup_iouser (&user, diruser->user);
       if (! err)
         {
-          newpi = netfs_make_protid (netfs_make_peropen (np, flags,
-                                                        diruser->po),
-                                    user);
-         if (newpi)
+         err = netfs_make_peropen (np, flags, diruser->po, &newpo);
+         if (! err)
+           {
+             err = netfs_make_protid (newpo, user, &newpi);
+             if (err)
+               netfs_release_peropen (newpo);
+           }
+
+         if (! err)
            {
              *newfile = ports_get_right (newpi);
              *newfiletype = MACH_MSG_TYPE_MAKE_SEND;
              ports_port_deref (newpi);
            }
          else
-           {
-             err = errno;
-             iohelp_free_iouser (user);
-           }
+           iohelp_free_iouser (user);
        }
       netfs_nput (np);
     }
Index: libnetfs/file-exec.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/file-exec.c,v
retrieving revision 1.9
diff -u -p -r1.9 file-exec.c
--- libnetfs/file-exec.c        9 Sep 2001 17:32:03 -0000       1.9
+++ libnetfs/file-exec.c        7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1996,97,2000,01 Free Software Foundation, Inc.
+   Copyright (C) 1996,97,2000,01,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -123,14 +123,21 @@ netfs_S_file_exec (struct protid *cred,
   if (! err)
     {
       struct iouser *user;
+      struct peropen *newpo;
       struct protid *newpi;
 
       err = iohelp_dup_iouser (&user, cred->user);
       if (! err)
         {
-         newpi = netfs_make_protid (netfs_make_peropen (np, O_READ, cred->po),
-                                    user);
-         if (newpi)
+         err = netfs_make_peropen (np, O_READ, cred->po, &newpo);
+         if (! err)
+           {
+             err = netfs_make_protid (newpo, user, &newpi);
+             if (err)
+               netfs_release_peropen (newpo);
+           }
+
+         if (! err)
            {
              right = ports_get_send_right (newpi);
              err = exec_exec (_netfs_exec,
@@ -145,10 +152,7 @@ netfs_S_file_exec (struct protid *cred,
              ports_port_deref (newpi);
            }
          else
-           {
-             err = errno;
-             iohelp_free_iouser (user);
-           }
+           iohelp_free_iouser (user);
        }
     }
 
Index: libnetfs/file-reparent.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/file-reparent.c,v
retrieving revision 1.4
diff -u -p -r1.4 file-reparent.c
--- libnetfs/file-reparent.c    16 Jun 2001 20:23:29 -0000      1.4
+++ libnetfs/file-reparent.c    7 Apr 2002 20:16:45 -0000
@@ -1,6 +1,6 @@
 /* Reparent a file
 
-   Copyright (C) 1997, 2001 Free Software Foundation
+   Copyright (C) 1997, 2001, 2002 Free Software Foundation
 
    Written by Miles Bader <miles@gnu.org>
 
@@ -28,6 +28,7 @@ netfs_S_file_reparent (struct protid *cr
 {
   error_t err;
   struct node *node;
+  struct peropen *newpo;
   struct protid *new_cred;
   struct iouser *user;
 
@@ -42,12 +43,17 @@ netfs_S_file_reparent (struct protid *cr
 
   mutex_lock (&node->lock);
   
-  new_cred =
-    netfs_make_protid (netfs_make_peropen (node, cred->po->openstat, cred->po),
-                      user);
+  err = netfs_make_peropen (node, cred->po->openstat, cred->po, &newpo);
+  if (! err)
+    {
+      err = netfs_make_protid (newpo, user, &new_cred);
+      if (err)
+       netfs_release_peropen(newpo);
+    }
+
   mutex_unlock (&node->lock);
 
-  if (new_cred)
+  if (! err)
     {
       /* Remove old shadow root state.  */
       if (new_cred->po->shadow_root && new_cred->po->shadow_root != node)
@@ -69,6 +75,7 @@ netfs_S_file_reparent (struct protid *cr
 
       return 0;
     }
-  else
-    return errno;
+
+  iohelp_free_iouser (user);
+  return err;
 }
Index: libnetfs/fsys-getroot.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/fsys-getroot.c,v
retrieving revision 1.10
diff -u -p -r1.10 fsys-getroot.c
--- libnetfs/fsys-getroot.c     16 Jun 2001 20:23:29 -0000      1.10
+++ libnetfs/fsys-getroot.c     7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1996, 1997, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 2001, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -41,6 +41,7 @@ netfs_S_fsys_getroot (mach_port_t cntl,
                                            netfs_control_class);
   struct iouser *cred;
   error_t err;
+  struct peropen *newpo;
   struct protid *newpi;
   mode_t type;
   struct peropen peropen_context = { root_parent: dotdot };
@@ -127,20 +128,28 @@ netfs_S_fsys_getroot (mach_port_t cntl,
   
   flags &= ~OPENONLY_STATE_MODES;
   
-  newpi = netfs_make_protid (netfs_make_peropen (netfs_root_node, flags,
-                                                &peropen_context),
-                            cred);
+  err = netfs_make_peropen (netfs_root_node, flags, &peropen_context, &newpo);
+  if (! err)
+    {
+      err = netfs_make_protid (newpo, cred, &newpi);
+      if (err)
+       netfs_release_peropen (newpo);
+    }
+
   mach_port_deallocate (mach_task_self (), dotdot);
 
-  *do_retry = FS_RETRY_NORMAL;
-  *retry_port = ports_get_right (newpi);
-  *retry_port_type = MACH_MSG_TYPE_MAKE_SEND;
-  retry_name[0] = '\0';
-  ports_port_deref (newpi);
-  
+  if (! err)
+    {      
+      *do_retry = FS_RETRY_NORMAL;
+      *retry_port = ports_get_right (newpi);
+      *retry_port_type = MACH_MSG_TYPE_MAKE_SEND;
+      retry_name[0] = '\0';
+      ports_port_deref (newpi);
+    }
+  else
  out:
-  if (err)
     iohelp_free_iouser (cred);
+
   mutex_unlock (&netfs_root_node->lock);
   return err;
 }
Index: libnetfs/io-duplicate.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/io-duplicate.c,v
retrieving revision 1.3
diff -u -p -r1.3 io-duplicate.c
--- libnetfs/io-duplicate.c     16 Jun 2001 20:23:29 -0000      1.3
+++ libnetfs/io-duplicate.c     7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995,96,2001 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,2001,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -35,10 +35,17 @@ netfs_S_io_duplicate (struct protid *use
     return err;
   
   mutex_lock (&user->po->np->lock);
-  newpi = netfs_make_protid (user->po, clone);
-  *newport = ports_get_right (newpi);
+  err = netfs_make_protid (user->po, clone, &newpi);
+  if (! err)
+    {
+      *newport = ports_get_right (newpi);
+      mutex_unlock (&user->po->np->lock);
+      *newporttp = MACH_MSG_TYPE_MAKE_SEND;
+      ports_port_deref (newpi);
+      return 0;
+    } 
+
   mutex_unlock (&user->po->np->lock);
-  *newporttp = MACH_MSG_TYPE_MAKE_SEND;
-  ports_port_deref (newpi);
-  return 0;
+  iohelp_free_iouser (clone);
+  return err;
 }
Index: libnetfs/io-reauthenticate.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/io-reauthenticate.c,v
retrieving revision 1.10
diff -u -p -r1.10 io-reauthenticate.c
--- libnetfs/io-reauthenticate.c        16 Jun 2001 20:23:29 -0000      1.10
+++ libnetfs/io-reauthenticate.c        7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1995,96,2000,01 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,2000,01,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -32,22 +32,29 @@ netfs_S_io_reauthenticate (struct protid
     return EOPNOTSUPP;
 
   mutex_lock (&user->po->np->lock);
-  newpi = netfs_make_protid (user->po, 0);
+  err = netfs_make_protid (user->po, 0, &newpi);
 
-  newright = ports_get_send_right (newpi);
-  assert (newright != MACH_PORT_NULL);
+  if (! err)
+    {
 
-  err = iohelp_reauth (&newpi->user, netfs_auth_server_port, rend_port,
-                      newright, 1);
+      newright = ports_get_send_right (newpi);
+      assert (newright != MACH_PORT_NULL);
+      
+      err = iohelp_reauth (&newpi->user, netfs_auth_server_port, rend_port,
+                          newright, 1);
+      
+      mach_port_deallocate (mach_task_self (), rend_port);
+      mach_port_deallocate (mach_task_self (), newright);
+      
+      mach_port_move_member (mach_task_self (), newpi->pi.port_right,
+                            netfs_port_bucket->portset);
+      
+      mutex_unlock (&user->po->np->lock);
+      ports_port_deref (newpi);
 
-  mach_port_deallocate (mach_task_self (), rend_port);
-  mach_port_deallocate (mach_task_self (), newright);
-
-  mach_port_move_member (mach_task_self (), newpi->pi.port_right,
-                        netfs_port_bucket->portset);
+      return err;
+    }
 
   mutex_unlock (&user->po->np->lock);
-  ports_port_deref (newpi);
-
   return err;
 }
Index: libnetfs/io-restrict-auth.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/io-restrict-auth.c,v
retrieving revision 1.4
diff -u -p -r1.4 io-restrict-auth.c
--- libnetfs/io-restrict-auth.c 16 Jun 2001 20:37:39 -0000      1.4
+++ libnetfs/io-restrict-auth.c 7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995,96,2001 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,2001,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -96,21 +96,19 @@ netfs_S_io_restrict_auth (struct protid 
     }
   
   mutex_lock (&user->po->np->lock);
-  newpi = netfs_make_protid (user->po, new_user);
-  if (newpi)
+  err = netfs_make_protid (user->po, new_user, &newpi);
+  if (! err)
     {
       *newport = ports_get_right (newpi);
-      mutex_unlock (&user->po->np->lock);
       *newporttype = MACH_MSG_TYPE_MAKE_SEND;
+      ports_port_deref (newpi);
     }
   else
-    {
-      mutex_unlock (&user->po->np->lock);
-      iohelp_free_iouser (new_user);
-      err = ENOMEM;
-    }
-  
-  ports_port_deref (newpi);
+    iohelp_free_iouser (new_user);
+
+  mutex_unlock (&user->po->np->lock);
+
   return err;
+  
 }
 
Index: libnetfs/make-peropen.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/make-peropen.c,v
retrieving revision 1.3
diff -u -p -r1.3 make-peropen.c
--- libnetfs/make-peropen.c     2 Mar 1997 21:12:03 -0000       1.3
+++ libnetfs/make-peropen.c     7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1997, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -21,11 +21,15 @@
 #include "netfs.h"
 #include <sys/file.h>
 
-struct peropen *
-netfs_make_peropen (struct node *np, int flags, struct peropen *context)
+error_t
+netfs_make_peropen (struct node *np, int flags, struct peropen *context,
+                   struct peropen **ppo)
 {
-  struct peropen *po = malloc (sizeof (struct peropen));
-  
+  struct peropen *po = *ppo = malloc (sizeof (struct peropen));
+
+  if (! po)
+    return ENOMEM;
+
   po->filepointer = 0;
   po->lock_status = LOCK_UN;
   po->refcnt = 0;
@@ -51,6 +55,6 @@ netfs_make_peropen (struct node *np, int
 
   netfs_nref (np);
 
-  return po;
+  return 0;
 }
 
Index: libnetfs/make-protid.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/make-protid.c,v
retrieving revision 1.6
diff -u -p -r1.6 make-protid.c
--- libnetfs/make-protid.c      18 Nov 1996 23:51:10 -0000      1.6
+++ libnetfs/make-protid.c      7 Apr 2002 20:16:45 -0000
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -20,26 +20,26 @@
 
 #include "netfs.h"
 
-struct protid *
-netfs_make_protid (struct peropen *po, struct iouser *cred)
+error_t
+netfs_make_protid (struct peropen *po, struct iouser *cred, struct protid **pi)
 {
-  struct protid *pi;
+  error_t err;
 
   if (cred)
-    errno = ports_create_port (netfs_protid_class, netfs_port_bucket, 
-                              sizeof (struct protid), &pi);
+    err = ports_create_port (netfs_protid_class, netfs_port_bucket, 
+                            sizeof (struct protid), pi);
   else
-    errno = ports_create_port_noinstall (netfs_protid_class,
-                                        netfs_port_bucket, 
-                                        sizeof (struct protid), &pi);
+    err = ports_create_port_noinstall (netfs_protid_class,
+                                      netfs_port_bucket, 
+                                      sizeof (struct protid), pi);
     
-  if (errno)
-    return 0;
+  if (err)
+      return err;
 
   po->refcnt++;
-  pi->po = po;
-  pi->user = cred;
-  pi->shared_object = MACH_PORT_NULL;
-  pi->mapped = 0;
-  return pi;
+  (*pi)->po = po;
+  (*pi)->user = cred;
+  (*pi)->shared_object = MACH_PORT_NULL;
+  (*pi)->mapped = 0;
+  return 0;
 }
Index: libnetfs/netfs.h
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/netfs.h,v
retrieving revision 1.29
diff -u -p -r1.29 netfs.h
--- libnetfs/netfs.h    30 Jan 2001 00:50:25 -0000      1.29
+++ libnetfs/netfs.h    7 Apr 2002 20:16:45 -0000
@@ -1,6 +1,6 @@
 /* 
 
-   Copyright (C) 1994, 1995, 1996, 1997, 1999, 2000 Free Software Foundation
+   Copyright (C) 1994,95,96,97,99,2000,02 Free Software Foundation
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -263,11 +263,6 @@ error_t netfs_attempt_write (struct ious
 error_t netfs_report_access (struct iouser *cred, struct node *np,
                             int *types);
 
-/* The user must define this function.  Create a new user from the
-   specified UID and GID arrays. */
-struct iouser *netfs_make_user (uid_t *uids, int nuids,
-                                      uid_t *gids, int ngids);
-
 /* The user must define this function.  Node NP has no more references;
    free all its associated storage. */
 void netfs_node_norefs (struct node *np);
@@ -363,15 +358,16 @@ mach_port_t netfs_startup (mach_port_t b
 void netfs_server_loop (void);
 
 /* Creates a new credential from USER which can be NULL on the peropen
-   PO.  Returns NULL and sets errno on error.  */
-struct protid *netfs_make_protid (struct peropen *po, struct iouser *user);
+   PO.  Returns the error value.  */
+error_t netfs_make_protid (struct peropen *po, struct iouser *user, 
+                          struct protid **pi);
 
-/* Create and return a new peropen structure on node NP with open
+/* Create a new peropen structure, *PPO, on node NP with open
    flags FLAGS.  The initial values for the root_parent, shadow_root,
    and shadow_root_parent fields are copied from CONTEXT if it's
-   non-zero, otherwise zeroed.  */
-struct peropen *netfs_make_peropen (struct node *, int,
-                                   struct peropen *context);
+   non-zero, otherwise zeroed.  Returns the error value. */
+error_t netfs_make_peropen (struct node *np, int, struct peropen *context,
+                           struct peropen **ppo);
 
 /* Add a reference to node NP. Unless you already hold a reference,
    NP must be locked.  */
Index: libnetfs/trans-callback.c
===================================================================
RCS file: /cvsroot/hurd/hurd/libnetfs/trans-callback.c,v
retrieving revision 1.2
diff -u -p -r1.2 trans-callback.c
--- libnetfs/trans-callback.c   16 Jun 2001 20:23:29 -0000      1.2
+++ libnetfs/trans-callback.c   7 Apr 2002 20:16:45 -0000
@@ -1,6 +1,6 @@
 /* Callback functions for starting translators
 
-   Copyright (C) 1995,96,97,2001 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,97,2001,2002 Free Software Foundation, Inc.
 
    This file is part of the GNU Hurd.
 
@@ -52,26 +52,34 @@ _netfs_translator_callback2_fn (void *co
                                mach_msg_type_name_t *underlying_type)
 {
   error_t err;
+  struct peropen *newpo;
   struct protid *cred;
   struct node *node = cookie1;
   struct iouser *user;
 
   err = iohelp_create_simple_iouser (&user, node->nn_stat.st_uid,
-                                  node->nn_stat.st_gid);
+                                    node->nn_stat.st_gid);
   if (err)
     return err;
+  
+  err = netfs_make_peropen (node, flags, cookie2, &newpo);
+  if (! err)
+    {
+      err = netfs_make_protid (newpo, user, &cred);
+      if (err)
+       netfs_release_peropen (newpo);
+    }
 
-  cred = netfs_make_protid (netfs_make_peropen (node, flags, cookie2),
-                           user);
-  if (cred)
+  if (! err)
     {
       *underlying = ports_get_right (cred);
       *underlying_type = MACH_MSG_TYPE_MAKE_SEND;
       ports_port_deref (cred);
       return 0;
     }
-  else
-    return errno;
+
+  iohelp_free_iouser (user);
+  return err;
 }
 
 fshelp_fetch_root_callback1_t _netfs_translator_callback1 =