Fix locking of Berkeley databases.

* include/mailutils/locker.h (mu_locker_lock_mode): New proto.
* libmailutils/base/locker.c (_mu_locker_lock): Rename to
mu_locker_lock_mode.  All callers updated.
* libmu_dbm/berkeley.c (bdb_file) <locker>: New member.
(do_bdb_open): New function.  Lock the database file before opening it.
Drop support for version 2.
(_bdb_open): Rewrite as a wrapper over do_bdb_open.
* mu/dbm.c (dbm_doc): Document the "dump" subcommand.

* NEWS: Version 2.99.96
* configure.ac: Likewise.

-GNU mailutils NEWS -- history of user-visible changes. 2011-12-31
+GNU mailutils NEWS -- history of user-visible changes. 2012-02-26
 Copyright (C) 2002-2012 Free Software Foundation, Inc.
 See the end of file for copying conditions.
 
 Please send mailutils bug reports to <bug-mailutils@gnu.org>.
 
 
-Version 2.99.95 (Git)
+Version 2.99.96 (Git)
 
 This version is a major rewrite of GNU Mailutils.  Quite a few parts
 of the basic framework were rewritten from scratch, while some others

@@ -16,7 +16,7 @@ dnl You should have received a copy of the GNU General Public License along
 dnl with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
 
 AC_PREREQ(2.63)
-AC_INIT([GNU Mailutils], [2.99.95], [bug-mailutils@gnu.org], [mailutils])
+AC_INIT([GNU Mailutils], [2.99.96], [bug-mailutils@gnu.org], [mailutils])
 AC_CONFIG_SRCDIR([libmailutils/mailbox/mailbox.c])
 AC_CONFIG_AUX_DIR([build-aux])
 AM_INIT_AUTOMAKE([gnits 1.11 dist-bzip2 dist-xz std-options silent-rules])

@@ -133,6 +133,7 @@ enum mu_locker_mode
                     locking otherwise */
 }; 
 
+extern int mu_locker_lock_mode (mu_locker_t, enum mu_locker_mode);
 extern int mu_locker_lock          (mu_locker_t);
 extern int mu_locker_touchlock     (mu_locker_t);
 extern int mu_locker_unlock        (mu_locker_t);

@@ -547,7 +547,7 @@ mu_locker_destroy (mu_locker_t *plocker)
 }
 
 int
-_mu_locker_lock (mu_locker_t lock, enum mu_locker_mode mode)
+mu_locker_lock_mode (mu_locker_t lock, enum mu_locker_mode mode)
 {
   int rc;
   unsigned type;
@@ -598,7 +598,7 @@ _mu_locker_lock (mu_locker_t lock, enum mu_locker_mode mode)
 int
 mu_locker_lock (mu_locker_t lock)
 {
-  return _mu_locker_lock (lock, mu_lck_exc);
+  return mu_locker_lock_mode (lock, mu_lck_exc);
 }
 
 int

@@ -26,6 +26,7 @@
 #include <mailutils/errno.h>
 #include <mailutils/error.h>
 #include <mailutils/stream.h>
+#include <mailutils/locker.h>
 #include "mudbm.h"
 
 #if defined(WITH_BDB)
@@ -35,6 +36,7 @@ struct bdb_file
 {
   DB *db;
   DBC *dbc;
+  mu_locker_t locker;
 };
 
 static int
@@ -59,57 +61,71 @@ _bdb_get_fd (mu_dbm_file_t db, int *pag, int *dir)
 }
   
 static int
-_bdb_open (mu_dbm_file_t mdb, int flags, int mode)
-{
-  struct bdb_file *bdb_file;
-  int f, rc;
-  DB *db;
-
+do_bdb_open (mu_dbm_file_t mdb, int flags, int mode)
+{  
+  struct bdb_file *bdb_file = mdb->db_descr;
+  int f, rc, locker_flags;
+  enum mu_locker_mode locker_mode;
+    
   switch (flags)
     {
     case MU_STREAM_CREAT:
       f = DB_CREATE|DB_TRUNCATE;
+      locker_mode = mu_lck_exc;
       break;
       
     case MU_STREAM_READ:
       f = DB_RDONLY;
+      locker_mode = mu_lck_shr;
       break;
       
     case MU_STREAM_RDWR:
       f = DB_CREATE;
+      locker_mode = mu_lck_exc;
       break;
       
     default:
       return EINVAL;
     }
 
-#if WITH_BDB == 2  
-  rc = db_open (db->db_name, DB_HASH, f, mode, NULL, NULL, &db);
+#ifdef DB_FCNTL_LOCKING
+  f |= DB_FCNTL_LOCKING;
+  locker_flags = MU_LOCKER_KERNEL;
 #else
-  rc = db_create (&db, NULL, 0);
-  if (rc != 0 || db == NULL)
-    return MU_ERR_FAILURE;
-# if DB_VERSION_MAJOR == 3
-  rc = db->open (db, mdb->db_name, NULL, DB_HASH, f, mode);
-# else
-  rc = db->open (db, NULL, mdb->db_name, NULL, DB_HASH, f, mode);
-# endif
+  locker_flags = 0;
 #endif
-  
+  rc = mu_locker_create (&bdb_file->locker, mdb->db_name,
+			 locker_flags|MU_LOCKER_RETRY);
   if (rc)
-    return MU_ERR_FAILURE;
+    return rc;
 
-  bdb_file = malloc (sizeof *bdb_file);
-  if (!bdb_file)
+  rc = mu_locker_lock_mode (bdb_file->locker, locker_mode);
+  switch (rc)
     {
-      db->close (db, 0);
-      return ENOMEM;
-    }
-  bdb_file->db = db;
-  bdb_file->dbc = NULL;
+    case 0:
+      break;
 
-  mdb->db_descr = bdb_file;
+    case EACCES:
+      mu_locker_destroy (&bdb_file->locker);
+      break;
+      
+    default:
+      return rc;
+    }
+  
+  rc = db_create (&bdb_file->db, NULL, 0);
+  if (rc != 0 || bdb_file->db == NULL)
+    return MU_ERR_FAILURE;
+#if DB_VERSION_MAJOR == 3
+  rc = bdb_file->db->open (bdb_file->db, mdb->db_name, NULL, DB_HASH, f, mode);
+#else
+  rc = bdb_file->db->open (bdb_file->db, NULL, mdb->db_name, NULL, DB_HASH,
+			   f, mode);
+#endif
   
+  if (rc)
+    return MU_ERR_FAILURE;
+
   return 0;
 }
 
@@ -119,7 +135,13 @@ _bdb_close (mu_dbm_file_t db)
   if (db->db_descr)
     {
       struct bdb_file *bdb_file = db->db_descr;
-      bdb_file->db->close (bdb_file->db, 0);
+      if (bdb_file->db)
+	bdb_file->db->close (bdb_file->db, 0);
+      if (bdb_file->locker)
+	{
+	  mu_locker_unlock (bdb_file->locker);
+	  mu_locker_destroy (&bdb_file->locker);
+	}
       free (bdb_file);
       db->db_descr = NULL;
     }
@@ -127,6 +149,23 @@ _bdb_close (mu_dbm_file_t db)
 }
 
 static int
+_bdb_open (mu_dbm_file_t mdb, int flags, int mode)
+{
+  int rc;
+  struct bdb_file *bdb_file;
+
+  bdb_file = calloc (1, sizeof *bdb_file);
+  if (!bdb_file)
+    return ENOMEM;
+
+  mdb->db_descr = bdb_file;
+  rc = do_bdb_open (mdb, flags, mode);
+  if (rc)
+    _bdb_close (mdb);
+  return rc;
+}
+
+static int
 _bdb_fetch (mu_dbm_file_t db, struct mu_dbm_datum const *key,
 	    struct mu_dbm_datum *ret)
 {

@@ -35,6 +35,7 @@ static char dbm_doc[] = N_("mu dbm - DBM management tool\n"
 "Valid COMMANDs are:\n"
 "\n"
 "  create or load - create the database\n"
+"  dump           - dump the database\n"
 "  list           - list contents of the database\n"
 "  delete         - delete specified keys from the database\n"
 "  add            - add records to the database\n"