source3/lib/dbwrap/dbwrap_open.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Database interface wrapper
   4
   5    Copyright (C) Volker Lendecke 2005-2007
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "dbwrap/dbwrap.h"
  23 #include "dbwrap/dbwrap_private.h"
  24 #include "dbwrap/dbwrap_open.h"
  25 #include "dbwrap/dbwrap_tdb.h"
  26 #include "dbwrap/dbwrap_ctdb.h"
  27 #include "lib/param/param.h"
  28 #include "lib/cluster_support.h"
  29 #include "lib/messages_ctdb.h"
  30 #include "util_tdb.h"
  31 #include "ctdbd_conn.h"
  32 #include "global_contexts.h"
  33
  34 bool db_is_local(const char *name)
  35 {
  36         const char *sockname = lp_ctdbd_socket();
  37
  38         if (lp_clustering() && socket_exist(sockname)) {
  39                 const char *partname;
  40                 /* ctdb only wants the file part of the name */
  41                 partname = strrchr(name, '/');
  42                 if (partname) {
  43                         partname++;
  44                 } else {
  45                         partname = name;
  46                 }
  47                 /* allow ctdb for individual databases to be disabled */
  48                 if (lp_parm_bool(-1, "ctdb", partname, True)) {
  49                         return false;
  50                 }
  51         }
  52
  53         return true;
  54 }
  55
  56 /**
  57  * open a database
  58  */
  59 struct db_context *db_open(TALLOC_CTX *mem_ctx,
  60                            const char *name,
  61                            int hash_size, int tdb_flags,
  62                            int open_flags, mode_t mode,
  63                            enum dbwrap_lock_order lock_order,
  64                            uint64_t dbwrap_flags)
  65 {
  66         struct db_context *result = NULL;
  67         const char *base;
  68         struct loadparm_context *lp_ctx = NULL;
  69
  70         if ((lock_order != DBWRAP_LOCK_ORDER_NONE) &&
  71             !DBWRAP_LOCK_ORDER_VALID(lock_order)) {
  72                 errno = EINVAL;
  73                 return NULL;
  74         }
  75
  76         base = strrchr_m(name, '/');
  77         if (base != NULL) {
  78                 base++;
  79         } else {
  80                 base = name;
  81         }
  82
  83         if (tdb_flags & TDB_CLEAR_IF_FIRST) {
  84                 bool try_readonly = false;
  85
  86                 if (dbwrap_flags & DBWRAP_FLAG_OPTIMIZE_READONLY_ACCESS) {
  87                         try_readonly = true;
  88                 }
  89
  90                 try_readonly = lp_parm_bool(-1, "dbwrap_optimize_readonly", "*", try_readonly);
  91                 try_readonly = lp_parm_bool(-1, "dbwrap_optimize_readonly", base, try_readonly);
  92
  93                 if (try_readonly) {
  94                         dbwrap_flags |= DBWRAP_FLAG_OPTIMIZE_READONLY_ACCESS;
  95                 } else {
  96                         dbwrap_flags &= ~DBWRAP_FLAG_OPTIMIZE_READONLY_ACCESS;
  97                 }
  98         }
  99
 100         if (tdb_flags & TDB_CLEAR_IF_FIRST) {
 101                 bool try_mutex = true;
 102                 bool require_mutex = false;
 103
 104                 try_mutex = lp_parm_bool(-1, "dbwrap_tdb_mutexes", "*", try_mutex);
 105                 try_mutex = lp_parm_bool(-1, "dbwrap_tdb_mutexes", base, try_mutex);
 106
 107                 if (!lp_use_mmap()) {
 108                         /*
 109                          * Mutexes require mmap. "use mmap = no" can
 110                          * be a debugging tool, so let it override the
 111                          * mutex parameters
 112                          */
 113                         try_mutex = false;
 114                 }
 115
 116                 if (try_mutex && tdb_runtime_check_for_robust_mutexes()) {
 117                         tdb_flags |= TDB_MUTEX_LOCKING;
 118                 }
 119
 120                 require_mutex = lp_parm_bool(-1, "dbwrap_tdb_require_mutexes",
 121                                            "*", require_mutex);
 122                 require_mutex = lp_parm_bool(-1, "dbwrap_tdb_require_mutexes",
 123                                            base, require_mutex);
 124
 125                 if (require_mutex) {
 126                         tdb_flags |= TDB_MUTEX_LOCKING;
 127                 }
 128         }
 129
 130         if (lp_clustering()) {
 131                 const char *sockname;
 132
 133                 sockname = lp_ctdbd_socket();
 134                 if (!socket_exist(sockname)) {
 135                         DBG_WARNING("ctdb socket does %s not exist - "
 136                                     "is ctdb not running?\n",
 137                                     sockname);
 138                         return NULL;
 139                 }
 140
 141                 /* allow ctdb for individual databases to be disabled */
 142                 if (lp_parm_bool(-1, "ctdb", base, true)) {
 143                         struct messaging_context *msg_ctx;
 144                         struct ctdbd_connection *conn;
 145
 146                         /*
 147                          * Initialize messaging before getting the ctdb
 148                          * connection, as the ctdb connection requires messaging
 149                          * to be initialized.
 150                          */
 151                         msg_ctx = global_messaging_context();
 152
 153                         conn = messaging_ctdb_connection();
 154                         if (conn == NULL) {
 155                                 DBG_WARNING("No ctdb connection\n");
 156                                 errno = EIO;
 157                                 return NULL;
 158                         }
 159
 160                         result = db_open_ctdb(mem_ctx, msg_ctx, base,
 161                                               hash_size,
 162                                               tdb_flags, open_flags, mode,
 163                                               lock_order, dbwrap_flags);
 164                         if (result == NULL) {
 165                                 DBG_ERR("failed to attach to ctdb %s\n", base);
 166                                 if (errno == 0) {
 167                                         errno = EIO;
 168                                 }
 169                                 return NULL;
 170                         }
 171
 172                         return result;
 173                 }
 174         }
 175
 176         lp_ctx = loadparm_init_s3(mem_ctx, loadparm_s3_helpers());
 177
 178         if (hash_size == 0) {
 179                 hash_size = lpcfg_tdb_hash_size(lp_ctx, name);
 180         }
 181         tdb_flags = lpcfg_tdb_flags(lp_ctx, tdb_flags);
 182
 183         result = dbwrap_local_open(mem_ctx,
 184                                    name,
 185                                    hash_size,
 186                                    tdb_flags,
 187                                    open_flags,
 188                                    mode,
 189                                    lock_order,
 190                                    dbwrap_flags);
 191         talloc_unlink(mem_ctx, lp_ctx);
 192         return result;
 193 }