ctdb/common/ctdb_ltdb.c

   1 /*
   2    ctdb ltdb code
   3
   4    Copyright (C) Andrew Tridgell  2006
   5    Copyright (C) Ronnie sahlberg  2011
   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 "replace.h"
  22 #include "system/network.h"
  23 #include "system/filesys.h"
  24
  25 #include <tdb.h>
  26
  27 #include "lib/tdb_wrap/tdb_wrap.h"
  28 #include "lib/util/dlinklist.h"
  29 #include "lib/util/debug.h"
  30
  31 #include "ctdb_private.h"
  32
  33 #include "common/common.h"
  34 #include "common/logging.h"
  35
  36
  37 /*
  38  * Calculate tdb flags based on database type
  39  */
  40 int ctdb_db_tdb_flags(uint8_t db_flags, bool with_valgrind, bool with_mutex)
  41 {
  42         int tdb_flags = 0;
  43
  44         if (db_flags & CTDB_DB_FLAGS_PERSISTENT) {
  45                 tdb_flags = TDB_DEFAULT;
  46
  47         } else if (db_flags & CTDB_DB_FLAGS_REPLICATED) {
  48                 tdb_flags = TDB_NOSYNC |
  49                             TDB_CLEAR_IF_FIRST |
  50                             TDB_INCOMPATIBLE_HASH;
  51
  52         } else {
  53                 tdb_flags = TDB_NOSYNC |
  54                             TDB_CLEAR_IF_FIRST |
  55                             TDB_INCOMPATIBLE_HASH;
  56
  57 #ifdef TDB_MUTEX_LOCKING
  58                 if (with_mutex && tdb_runtime_check_for_robust_mutexes()) {
  59                         tdb_flags |= TDB_MUTEX_LOCKING;
  60                 }
  61 #endif
  62
  63         }
  64
  65         tdb_flags |= TDB_DISALLOW_NESTING;
  66         if (with_valgrind) {
  67                 tdb_flags |= TDB_NOMMAP;
  68         }
  69
  70         return tdb_flags;
  71 }
  72
  73 /*
  74   find an attached ctdb_db handle given a name
  75  */
  76 struct ctdb_db_context *ctdb_db_handle(struct ctdb_context *ctdb, const char *name)
  77 {
  78         struct ctdb_db_context *tmp_db;
  79         for (tmp_db=ctdb->db_list;tmp_db;tmp_db=tmp_db->next) {
  80                 if (strcmp(name, tmp_db->db_name) == 0) {
  81                         return tmp_db;
  82                 }
  83         }
  84         return NULL;
  85 }
  86
  87 bool ctdb_db_persistent(struct ctdb_db_context *ctdb_db)
  88 {
  89         if (ctdb_db->db_flags & CTDB_DB_FLAGS_PERSISTENT) {
  90                 return true;
  91         }
  92         return false;
  93 }
  94
  95 bool ctdb_db_replicated(struct ctdb_db_context *ctdb_db)
  96 {
  97         if (ctdb_db->db_flags & CTDB_DB_FLAGS_REPLICATED) {
  98                 return true;
  99         }
 100         return false;
 101 }
 102
 103 bool ctdb_db_volatile(struct ctdb_db_context *ctdb_db)
 104 {
 105         if ((ctdb_db->db_flags & CTDB_DB_FLAGS_PERSISTENT) ||
 106             (ctdb_db->db_flags & CTDB_DB_FLAGS_REPLICATED)) {
 107                 return false;
 108         }
 109         return true;
 110 }
 111
 112 bool ctdb_db_readonly(struct ctdb_db_context *ctdb_db)
 113 {
 114         if (ctdb_db->db_flags & CTDB_DB_FLAGS_READONLY) {
 115                 return true;
 116         }
 117         return false;
 118 }
 119
 120 void ctdb_db_set_readonly(struct ctdb_db_context *ctdb_db)
 121 {
 122         ctdb_db->db_flags |= CTDB_DB_FLAGS_READONLY;
 123 }
 124
 125 void ctdb_db_reset_readonly(struct ctdb_db_context *ctdb_db)
 126 {
 127         ctdb_db->db_flags &= ~CTDB_DB_FLAGS_READONLY;
 128 }
 129
 130 bool ctdb_db_sticky(struct ctdb_db_context *ctdb_db)
 131 {
 132         if (ctdb_db->db_flags & CTDB_DB_FLAGS_STICKY) {
 133                 return true;
 134         }
 135         return false;
 136 }
 137
 138 void ctdb_db_set_sticky(struct ctdb_db_context *ctdb_db)
 139 {
 140         ctdb_db->db_flags |= CTDB_DB_FLAGS_STICKY;
 141 }
 142
 143 /*
 144   return the lmaster given a key
 145 */
 146 uint32_t ctdb_lmaster(struct ctdb_context *ctdb, const TDB_DATA *key)
 147 {
 148         uint32_t idx, lmaster;
 149
 150         idx = ctdb_hash(key) % ctdb->vnn_map->size;
 151         lmaster = ctdb->vnn_map->map[idx];
 152
 153         return lmaster;
 154 }
 155
 156
 157 /*
 158   construct an initial header for a record with no ltdb header yet
 159 */
 160 static void ltdb_initial_header(struct ctdb_db_context *ctdb_db,
 161                                 TDB_DATA key,
 162                                 struct ctdb_ltdb_header *header)
 163 {
 164         ZERO_STRUCTP(header);
 165         /* initial dmaster is the lmaster */
 166         header->dmaster = ctdb_lmaster(ctdb_db->ctdb, &key);
 167         header->flags = CTDB_REC_FLAG_AUTOMATIC;
 168 }
 169
 170 struct ctdb_ltdb_fetch_state {
 171         struct ctdb_ltdb_header *header;
 172         TALLOC_CTX *mem_ctx;
 173         TDB_DATA *data;
 174         int ret;
 175         bool found;
 176 };
 177
 178 static int ctdb_ltdb_fetch_fn(TDB_DATA key, TDB_DATA data, void *private_data)
 179 {
 180         struct ctdb_ltdb_fetch_state *state = private_data;
 181         struct ctdb_ltdb_header *header = state->header;
 182         TDB_DATA *dstdata = state->data;
 183
 184         if (data.dsize < sizeof(*header)) {
 185                 return 0;
 186         }
 187
 188         state->found = true;
 189         memcpy(header, data.dptr, sizeof(*header));
 190
 191         if (dstdata != NULL) {
 192                 dstdata->dsize = data.dsize - sizeof(struct ctdb_ltdb_header);
 193                 dstdata->dptr = talloc_memdup(
 194                         state->mem_ctx,
 195                         data.dptr + sizeof(struct ctdb_ltdb_header),
 196                         dstdata->dsize);
 197                 if (dstdata->dptr == NULL) {
 198                         state->ret = -1;
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205 /*
 206   fetch a record from the ltdb, separating out the header information
 207   and returning the body of the record. A valid (initial) header is
 208   returned if the record is not present
 209 */
 210 int ctdb_ltdb_fetch(struct ctdb_db_context *ctdb_db,
 211                     TDB_DATA key, struct ctdb_ltdb_header *header,
 212                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
 213 {
 214         struct ctdb_context *ctdb = ctdb_db->ctdb;
 215         struct ctdb_ltdb_fetch_state state = {
 216                 .header = header,
 217                 .mem_ctx = mem_ctx,
 218                 .data = data,
 219                 .found = false,
 220         };
 221         int ret;
 222
 223         ret = tdb_parse_record(
 224                 ctdb_db->ltdb->tdb, key, ctdb_ltdb_fetch_fn, &state);
 225
 226         if (ret == -1) {
 227                 enum TDB_ERROR err = tdb_error(ctdb_db->ltdb->tdb);
 228                 if (err != TDB_ERR_NOEXIST) {
 229                         return -1;
 230                 }
 231         }
 232
 233         if (state.ret != 0) {
 234                 DBG_DEBUG("ctdb_ltdb_fetch_fn failed\n");
 235                 return state.ret;
 236         }
 237
 238         if (state.found) {
 239                 return 0;
 240         }
 241
 242         if (data != NULL) {
 243                 *data = tdb_null;
 244         }
 245
 246         if (ctdb->vnn_map == NULL) {
 247                 /* called from the client */
 248                 header->dmaster = (uint32_t)-1;
 249                 return -1;
 250         }
 251
 252         ltdb_initial_header(ctdb_db, key, header);
 253         if (ctdb_db_persistent(ctdb_db) ||
 254             header->dmaster == ctdb_db->ctdb->pnn) {
 255
 256                 ret = ctdb_ltdb_store(ctdb_db, key, header, tdb_null);
 257                 if (ret != 0) {
 258                         DBG_NOTICE("failed to store initial header\n");
 259                 }
 260         }
 261
 262         return 0;
 263 }
 264
 265 /*
 266   write a record to a normal database
 267 */
 268 int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key,
 269                     struct ctdb_ltdb_header *header, TDB_DATA data)
 270 {
 271         struct ctdb_context *ctdb = ctdb_db->ctdb;
 272         TDB_DATA rec[2];
 273         uint32_t hsize = sizeof(struct ctdb_ltdb_header);
 274         int ret;
 275
 276         if (ctdb_db->ctdb_ltdb_store_fn) {
 277                 return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data);
 278         }
 279
 280         if (ctdb->flags & CTDB_FLAG_TORTURE) {
 281                 TDB_DATA old;
 282                 struct ctdb_ltdb_header *h2;
 283
 284                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 285                 h2 = (struct ctdb_ltdb_header *)old.dptr;
 286                 if (old.dptr != NULL && old.dsize >= hsize &&
 287                     h2->rsn > header->rsn) {
 288                         DEBUG(DEBUG_ERR,
 289                               ("RSN regression! %"PRIu64" %"PRIu64"\n",
 290                                h2->rsn, header->rsn));
 291                 }
 292                 if (old.dptr != NULL) {
 293                         free(old.dptr);
 294                 }
 295         }
 296
 297         rec[0].dsize = hsize;
 298         rec[0].dptr = (uint8_t *)header;
 299
 300         rec[1].dsize = data.dsize;
 301         rec[1].dptr = data.dptr;
 302
 303         ret = tdb_storev(ctdb_db->ltdb->tdb, key, rec, 2, TDB_REPLACE);
 304         if (ret != 0) {
 305                 DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n"));
 306         }
 307
 308         return ret;
 309 }
 310
 311 /*
 312   lock a record in the ltdb, given a key
 313  */
 314 int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 315 {
 316         return tdb_chainlock(ctdb_db->ltdb->tdb, key);
 317 }
 318
 319 /*
 320   unlock a record in the ltdb, given a key
 321  */
 322 int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 323 {
 324         int ret = tdb_chainunlock(ctdb_db->ltdb->tdb, key);
 325         if (ret != 0) {
 326                 DEBUG(DEBUG_ERR,("tdb_chainunlock failed on db %s [%s]\n", ctdb_db->db_name, tdb_errorstr(ctdb_db->ltdb->tdb)));
 327         }
 328         return ret;
 329 }
 330
 331
 332 /*
 333   delete a record from a normal database
 334 */
 335 int ctdb_ltdb_delete(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 336 {
 337         if (! ctdb_db_volatile(ctdb_db)) {
 338                 DEBUG(DEBUG_WARNING,
 339                       ("Ignored deletion of empty record from "
 340                        "non-volatile database\n"));
 341                 return 0;
 342         }
 343         if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
 344                 DEBUG(DEBUG_ERR,("Failed to delete empty record.\n"));
 345                 return -1;
 346         }
 347         return 0;
 348 }
 349
 350 int ctdb_trackingdb_add_pnn(struct ctdb_context *ctdb, TDB_DATA *data, uint32_t pnn)
 351 {
 352         unsigned int byte_pos = pnn / 8;
 353         unsigned char bit_mask = 1 << (pnn % 8);
 354
 355         if (byte_pos + 1 > data->dsize) {
 356                 char *buf;
 357
 358                 buf = malloc(byte_pos + 1);
 359                 memset(buf, 0, byte_pos + 1);
 360                 if (buf == NULL) {
 361                         DEBUG(DEBUG_ERR, ("Out of memory when allocating buffer of %d bytes for trackingdb\n", byte_pos + 1));
 362                         return -1;
 363                 }
 364                 if (data->dptr != NULL) {
 365                         memcpy(buf, data->dptr, data->dsize);
 366                         free(data->dptr);
 367                 }
 368                 data->dptr  = (uint8_t *)buf;
 369                 data->dsize = byte_pos + 1;
 370         }
 371
 372         data->dptr[byte_pos] |= bit_mask;
 373         return 0;
 374 }
 375
 376 void ctdb_trackingdb_traverse(struct ctdb_context *ctdb, TDB_DATA data, ctdb_trackingdb_cb cb, void *private_data)
 377 {
 378         unsigned int i;
 379
 380         for(i = 0; i < data.dsize; i++) {
 381                 unsigned int j;
 382
 383                 for (j=0; j<8; j++) {
 384                         int mask = 1<<j;
 385
 386                         if (data.dptr[i] & mask) {
 387                                 cb(ctdb, i * 8 + j, private_data);
 388                         }
 389                 }
 390         }
 391 }
 392
 393 /*
 394   this is the dummy null procedure that all databases support
 395 */
 396 int ctdb_null_func(struct ctdb_call_info *call)
 397 {
 398         return 0;
 399 }
 400
 401 /*
 402   this is a plain fetch procedure that all databases support
 403 */
 404 int ctdb_fetch_func(struct ctdb_call_info *call)
 405 {
 406         call->reply_data = &call->record_data;
 407         return 0;
 408 }
 409
 410 /*
 411   this is a plain fetch procedure that all databases support
 412   this returns the full record including the ltdb header
 413 */
 414 int ctdb_fetch_with_header_func(struct ctdb_call_info *call)
 415 {
 416         call->reply_data = talloc(call, TDB_DATA);
 417         if (call->reply_data == NULL) {
 418                 return -1;
 419         }
 420         call->reply_data->dsize = sizeof(struct ctdb_ltdb_header) + call->record_data.dsize;
 421         call->reply_data->dptr  = talloc_size(call->reply_data, call->reply_data->dsize);
 422         if (call->reply_data->dptr == NULL) {
 423                 return -1;
 424         }
 425         memcpy(call->reply_data->dptr, call->header, sizeof(struct ctdb_ltdb_header));
 426         memcpy(&call->reply_data->dptr[sizeof(struct ctdb_ltdb_header)], call->record_data.dptr, call->record_data.dsize);
 427
 428         return 0;
 429 }
 430