libctdb/sync.c

   1 /*
   2    synchronous wrappers for libctdb
   3
   4    Copyright (C) Rusty Russell 2010
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19 #include <sys/time.h>
  20 #include <sys/socket.h>
  21 #include <ctdb.h>
  22 #include <stdbool.h>
  23 #include <poll.h>
  24 #include <errno.h>
  25 #include <stdlib.h>
  26 #include "libctdb_private.h"
  27
  28 /* Remove type-safety macros. */
  29 #undef ctdb_set_message_handler
  30
  31 /* On failure, frees req and returns NULL. */
  32 static struct ctdb_request *synchronous(struct ctdb_connection *ctdb,
  33                                         struct ctdb_request *req,
  34                                         bool *done)
  35 {
  36         struct pollfd fds;
  37
  38         /* Pass through allocation failures. */
  39         if (!req)
  40                 return NULL;
  41
  42         fds.fd = ctdb_get_fd(ctdb);
  43         while (!*done) {
  44                 fds.events = ctdb_which_events(ctdb);
  45                 if (poll(&fds, 1, -1) < 0) {
  46                         /* Signalled is OK, other error is bad. */
  47                         if (errno == EINTR)
  48                                 continue;
  49                         ctdb_cancel(ctdb, req);
  50                         DEBUG(ctdb, LOG_ERR, "ctdb_synchronous: poll failed");
  51                         return NULL;
  52                 }
  53                 if (!ctdb_service(ctdb, fds.revents)) {
  54                         /* It can have failed after it completed request. */
  55                         if (!*done)
  56                                 ctdb_cancel(ctdb, req);
  57                         else
  58                                 ctdb_request_free(req);
  59                         return NULL;
  60                 }
  61         }
  62         return req;
  63 }
  64
  65 static void set(struct ctdb_connection *ctdb,
  66                 struct ctdb_request *req, bool *done)
  67 {
  68         *done = true;
  69 }
  70
  71 bool ctdb_getrecmaster(struct ctdb_connection *ctdb,
  72                        uint32_t destnode, uint32_t *recmaster)
  73 {
  74         struct ctdb_request *req;
  75         bool done = false;
  76         bool ret = false;
  77
  78         req = synchronous(ctdb,
  79                           ctdb_getrecmaster_send(ctdb, destnode, set, &done),
  80                           &done);
  81         if (req != NULL) {
  82                 ret = ctdb_getrecmaster_recv(ctdb, req, recmaster);
  83                 ctdb_request_free(req);
  84         }
  85         return ret;
  86 }
  87
  88 bool ctdb_getrecmode(struct ctdb_connection *ctdb,
  89                        uint32_t destnode, uint32_t *recmode)
  90 {
  91         struct ctdb_request *req;
  92         bool done = false;
  93         bool ret = false;
  94
  95         req = synchronous(ctdb,
  96                           ctdb_getrecmode_send(ctdb, destnode, set, &done),
  97                           &done);
  98         if (req != NULL) {
  99                 ret = ctdb_getrecmode_recv(ctdb, req, recmode);
 100                 ctdb_request_free(req);
 101         }
 102         return ret;
 103 }
 104
 105 struct ctdb_db *ctdb_attachdb(struct ctdb_connection *ctdb,
 106                               const char *name, bool persistent,
 107                               uint32_t tdb_flags)
 108 {
 109         struct ctdb_request *req;
 110         bool done = false;
 111         struct ctdb_db *ret = NULL;
 112
 113         req = synchronous(ctdb,
 114                           ctdb_attachdb_send(ctdb, name, persistent, tdb_flags,
 115                                              set, &done),
 116                           &done);
 117         if (req != NULL) {
 118                 ret = ctdb_attachdb_recv(ctdb, req);
 119                 ctdb_request_free(req);
 120         }
 121         return ret;
 122 }
 123
 124 bool ctdb_getpnn(struct ctdb_connection *ctdb,
 125                  uint32_t destnode, uint32_t *pnn)
 126 {
 127         struct ctdb_request *req;
 128         bool done = false;
 129         bool ret = false;
 130
 131         req = synchronous(ctdb,
 132                           ctdb_getpnn_send(ctdb, destnode, set, &done),
 133                           &done);
 134         if (req != NULL) {
 135                 ret = ctdb_getpnn_recv(ctdb, req, pnn);
 136                 ctdb_request_free(req);
 137         }
 138         return ret;
 139 }
 140
 141 bool ctdb_getdbstat(struct ctdb_connection *ctdb,
 142                     uint32_t destnode, uint32_t db_id,
 143                     struct ctdb_db_statistics **stat)
 144 {
 145         struct ctdb_request *req;
 146         bool done = false;
 147         bool ret = false;
 148
 149         req = synchronous(ctdb,
 150                           ctdb_getdbstat_send(ctdb, destnode, db_id, set, &done),
 151                           &done);
 152         if (req != NULL) {
 153                 ret = ctdb_getdbstat_recv(ctdb, req, stat);
 154                 ctdb_request_free(req);
 155         }
 156         return ret;
 157 }
 158
 159 bool ctdb_check_message_handlers(struct ctdb_connection *ctdb,
 160                       uint32_t destnode, uint32_t num,
 161                       uint64_t *mhs, uint8_t *result)
 162 {
 163         struct ctdb_request *req;
 164         bool done = false;
 165         bool ret = false;
 166
 167         req = synchronous(ctdb,
 168                           ctdb_check_message_handlers_send(ctdb, destnode, num, mhs, set, &done),
 169                           &done);
 170         if (req != NULL) {
 171                 ret = ctdb_check_message_handlers_recv(ctdb, req, num, result);
 172                 ctdb_request_free(req);
 173         }
 174         return ret;
 175 }
 176
 177 bool ctdb_getnodemap(struct ctdb_connection *ctdb,
 178                  uint32_t destnode, struct ctdb_node_map **nodemap)
 179 {
 180         struct ctdb_request *req;
 181         bool done = false;
 182         bool ret = false;
 183
 184         *nodemap = NULL;
 185
 186         req = synchronous(ctdb,
 187                           ctdb_getnodemap_send(ctdb, destnode, set, &done),
 188                           &done);
 189         if (req != NULL) {
 190                 ret = ctdb_getnodemap_recv(ctdb, req, nodemap);
 191                 ctdb_request_free(req);
 192         }
 193         return ret;
 194 }
 195
 196 bool ctdb_getpublicips(struct ctdb_connection *ctdb,
 197                        uint32_t destnode, struct ctdb_all_public_ips **ips)
 198 {
 199         struct ctdb_request *req;
 200         bool done = false;
 201         bool ret = false;
 202
 203         *ips = NULL;
 204
 205         req = synchronous(ctdb,
 206                           ctdb_getpublicips_send(ctdb, destnode, set, &done),
 207                           &done);
 208         if (req != NULL) {
 209                 ret = ctdb_getpublicips_recv(ctdb, req, ips);
 210                 ctdb_request_free(req);
 211         }
 212         return ret;
 213 }
 214
 215 bool ctdb_set_message_handler(struct ctdb_connection *ctdb, uint64_t srvid,
 216                               ctdb_message_fn_t handler, void *cbdata)
 217 {
 218         struct ctdb_request *req;
 219         bool done = false;
 220         bool ret = false;
 221
 222         req = synchronous(ctdb,
 223                           ctdb_set_message_handler_send(ctdb, srvid, handler,
 224                                                         cbdata, set, &done),
 225                           &done);
 226         if (req != NULL) {
 227                 ret = ctdb_set_message_handler_recv(ctdb, req);
 228                 ctdb_request_free(req);
 229         }
 230         return ret;
 231 }
 232
 233 struct rrl_info {
 234         bool done;
 235         struct ctdb_lock *lock;
 236         TDB_DATA *data;
 237 };
 238
 239 static void rrl_callback(struct ctdb_db *ctdb_db,
 240                          struct ctdb_lock *lock,
 241                          TDB_DATA data,
 242                          struct rrl_info *rrl)
 243 {
 244         rrl->done = true;
 245         rrl->lock = lock;
 246         *rrl->data = data;
 247 }
 248
 249 struct ctdb_lock *ctdb_readrecordlock(struct ctdb_connection *ctdb,
 250                                       struct ctdb_db *ctdb_db, TDB_DATA key,
 251                                       TDB_DATA *data)
 252 {
 253         struct pollfd fds;
 254         struct rrl_info rrl;
 255
 256         rrl.done = false;
 257         rrl.lock = NULL;
 258         rrl.data = data;
 259
 260         /* Immediate failure is easy. */
 261         if (!ctdb_readrecordlock_async(ctdb_db, key, rrl_callback, &rrl))
 262                 return NULL;
 263
 264         /* Immediate success is easy. */
 265         if (!rrl.done) {
 266                 /* Otherwise wait until callback called. */
 267                 fds.fd = ctdb_get_fd(ctdb);
 268                 while (!rrl.done) {
 269                         fds.events = ctdb_which_events(ctdb);
 270                         if (poll(&fds, 1, -1) < 0) {
 271                                 /* Signalled is OK, other error is bad. */
 272                                 if (errno == EINTR)
 273                                         continue;
 274                                 DEBUG(ctdb, LOG_ERR,
 275                                       "ctdb_readrecordlock: poll failed");
 276                                 return NULL;
 277                         }
 278                         if (!ctdb_service(ctdb, fds.revents)) {
 279                                 break;
 280                         }
 281                 }
 282         }
 283         return rrl.lock;
 284 }
 285
 286 bool ctdb_getdbseqnum(struct ctdb_connection *ctdb,
 287                       uint32_t destnode, uint32_t dbid,
 288                       uint64_t *seqnum)
 289 {
 290         struct ctdb_request *req;
 291         bool done = false;
 292         bool ret = false;
 293
 294         req = synchronous(ctdb,
 295                           ctdb_getdbseqnum_send(ctdb, destnode, dbid, set, &done),
 296                           &done);
 297         if (req != NULL) {
 298                 ret = ctdb_getdbseqnum_recv(ctdb, req, seqnum);
 299                 ctdb_request_free(req);
 300         }
 301         return ret;
 302 }
 303
 304 bool ctdb_getifaces(struct ctdb_connection *ctdb,
 305                     uint32_t destnode, struct ctdb_ifaces_list **ifaces)
 306 {
 307         struct ctdb_request *req;
 308         bool done = false;
 309         bool ret = false;
 310
 311         *ifaces = NULL;
 312
 313         req = synchronous(ctdb,
 314                           ctdb_getifaces_send(ctdb, destnode, set, &done),
 315                           &done);
 316         if (req != NULL) {
 317                 ret = ctdb_getifaces_recv(ctdb, req, ifaces);
 318                 ctdb_request_free(req);
 319         }
 320         return ret;
 321 }
 322
 323 bool ctdb_getvnnmap(struct ctdb_connection *ctdb,
 324                     uint32_t destnode, struct ctdb_vnn_map **vnnmap)
 325 {
 326         struct ctdb_request *req;
 327         bool done = false;
 328         bool ret = false;
 329
 330         *vnnmap = NULL;
 331
 332         req = synchronous(ctdb,
 333                           ctdb_getvnnmap_send(ctdb, destnode, set, &done),
 334                           &done);
 335         if (req != NULL) {
 336                 ret = ctdb_getvnnmap_recv(ctdb, req, vnnmap);
 337                 ctdb_request_free(req);
 338         }
 339         return ret;
 340 }
 341
 342 bool ctdb_getcapabilities(struct ctdb_connection *ctdb,
 343                           uint32_t destnode, uint32_t *capabilities)
 344 {
 345         struct ctdb_request *req;
 346         bool done = false;
 347         bool ret = false;
 348
 349         req = synchronous(ctdb,
 350                           ctdb_getcapabilities_send(ctdb, destnode, set, &done),
 351                           &done);
 352         if (req != NULL) {
 353                 ret = ctdb_getcapabilities_recv(ctdb, req, capabilities);
 354                 ctdb_request_free(req);
 355         }
 356         return ret;
 357 }
 358