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 "includes.h"
  22 #include "tdb.h"
  23 #include "system/network.h"
  24 #include "system/filesys.h"
  25 #include "../include/ctdb_private.h"
  26 #include "lib/tdb_wrap/tdb_wrap.h"
  27 #include "lib/util/dlinklist.h"
  28
  29 /*
  30   find an attached ctdb_db handle given a name
  31  */
  32 struct ctdb_db_context *ctdb_db_handle(struct ctdb_context *ctdb, const char *name)
  33 {
  34         struct ctdb_db_context *tmp_db;
  35         for (tmp_db=ctdb->db_list;tmp_db;tmp_db=tmp_db->next) {
  36                 if (strcmp(name, tmp_db->db_name) == 0) {
  37                         return tmp_db;
  38                 }
  39         }
  40         return NULL;
  41 }
  42
  43
  44 /*
  45   return the lmaster given a key
  46 */
  47 uint32_t ctdb_lmaster(struct ctdb_context *ctdb, const TDB_DATA *key)
  48 {
  49         uint32_t idx, lmaster;
  50
  51         idx = ctdb_hash(key) % ctdb->vnn_map->size;
  52         lmaster = ctdb->vnn_map->map[idx];
  53
  54         return lmaster;
  55 }
  56
  57
  58 /*
  59   construct an initial header for a record with no ltdb header yet
  60 */
  61 static void ltdb_initial_header(struct ctdb_db_context *ctdb_db,
  62                                 TDB_DATA key,
  63                                 struct ctdb_ltdb_header *header)
  64 {
  65         ZERO_STRUCTP(header);
  66         /* initial dmaster is the lmaster */
  67         header->dmaster = ctdb_lmaster(ctdb_db->ctdb, &key);
  68         header->flags = CTDB_REC_FLAG_AUTOMATIC;
  69 }
  70
  71
  72 /*
  73   fetch a record from the ltdb, separating out the header information
  74   and returning the body of the record. A valid (initial) header is
  75   returned if the record is not present
  76 */
  77 int ctdb_ltdb_fetch(struct ctdb_db_context *ctdb_db,
  78                     TDB_DATA key, struct ctdb_ltdb_header *header,
  79                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
  80 {
  81         TDB_DATA rec;
  82         struct ctdb_context *ctdb = ctdb_db->ctdb;
  83
  84         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
  85         if (rec.dsize < sizeof(*header)) {
  86                 /* return an initial header */
  87                 if (rec.dptr) free(rec.dptr);
  88                 if (ctdb->vnn_map == NULL) {
  89                         /* called from the client */
  90                         ZERO_STRUCTP(data);
  91                         header->dmaster = (uint32_t)-1;
  92                         return -1;
  93                 }
  94                 ltdb_initial_header(ctdb_db, key, header);
  95                 if (data) {
  96                         *data = tdb_null;
  97                 }
  98                 if (ctdb_db->persistent || header->dmaster == ctdb_db->ctdb->pnn) {
  99                         if (ctdb_ltdb_store(ctdb_db, key, header, tdb_null) != 0) {
 100                                 DEBUG(DEBUG_NOTICE,
 101                                       (__location__ "failed to store initial header\n"));
 102                         }
 103                 }
 104                 return 0;
 105         }
 106
 107         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 108
 109         if (data) {
 110                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 111                 data->dptr = talloc_memdup(mem_ctx,
 112                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 113                                            data->dsize);
 114         }
 115
 116         free(rec.dptr);
 117         if (data) {
 118                 CTDB_NO_MEMORY(ctdb, data->dptr);
 119         }
 120
 121         return 0;
 122 }
 123
 124 /*
 125   fetch a record from the ltdb, separating out the header information
 126   and returning the body of the record.
 127   if the record does not exist, *header will be NULL
 128   and data = {0, NULL}
 129 */
 130 int ctdb_ltdb_fetch_with_header(struct ctdb_db_context *ctdb_db,
 131                     TDB_DATA key, struct ctdb_ltdb_header *header,
 132                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
 133 {
 134         TDB_DATA rec;
 135
 136         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 137         if (rec.dsize < sizeof(*header)) {
 138                 free(rec.dptr);
 139
 140                 data->dsize = 0;
 141                 data->dptr = NULL;
 142                 return -1;
 143         }
 144
 145         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 146         if (data) {
 147                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 148                 data->dptr = talloc_memdup(mem_ctx,
 149                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 150                                            data->dsize);
 151         }
 152
 153         free(rec.dptr);
 154
 155         return 0;
 156 }
 157
 158
 159 /*
 160   write a record to a normal database
 161 */
 162 int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key,
 163                     struct ctdb_ltdb_header *header, TDB_DATA data)
 164 {
 165         struct ctdb_context *ctdb = ctdb_db->ctdb;
 166         TDB_DATA rec;
 167         int ret;
 168         bool seqnum_suppressed = false;
 169
 170         if (ctdb_db->ctdb_ltdb_store_fn) {
 171                 return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data);
 172         }
 173
 174         if (ctdb->flags & CTDB_FLAG_TORTURE) {
 175                 struct ctdb_ltdb_header *h2;
 176                 rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 177                 h2 = (struct ctdb_ltdb_header *)rec.dptr;
 178                 if (rec.dptr && rec.dsize >= sizeof(h2) && h2->rsn > header->rsn) {
 179                         DEBUG(DEBUG_CRIT,("RSN regression! %llu %llu\n",
 180                                  (unsigned long long)h2->rsn, (unsigned long long)header->rsn));
 181                 }
 182                 if (rec.dptr) free(rec.dptr);
 183         }
 184
 185         rec.dsize = sizeof(*header) + data.dsize;
 186         rec.dptr = talloc_size(ctdb, rec.dsize);
 187         CTDB_NO_MEMORY(ctdb, rec.dptr);
 188
 189         memcpy(rec.dptr, header, sizeof(*header));
 190         memcpy(rec.dptr + sizeof(*header), data.dptr, data.dsize);
 191
 192         /* Databases with seqnum updates enabled only get their seqnum
 193            changes when/if we modify the data */
 194         if (ctdb_db->seqnum_update != NULL) {
 195                 TDB_DATA old;
 196                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 197
 198                 if ( (old.dsize == rec.dsize)
 199                 && !memcmp(old.dptr+sizeof(struct ctdb_ltdb_header),
 200                           rec.dptr+sizeof(struct ctdb_ltdb_header),
 201                           rec.dsize-sizeof(struct ctdb_ltdb_header)) ) {
 202                         tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 203                         seqnum_suppressed = true;
 204                 }
 205                 if (old.dptr) free(old.dptr);
 206         }
 207         ret = tdb_store(ctdb_db->ltdb->tdb, key, rec, TDB_REPLACE);
 208         if (ret != 0) {
 209                 DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n"));
 210         }
 211         if (seqnum_suppressed) {
 212                 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 213         }
 214
 215         talloc_free(rec.dptr);
 216
 217         return ret;
 218 }
 219
 220 /*
 221   lock a record in the ltdb, given a key
 222  */
 223 int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 224 {
 225         return tdb_chainlock(ctdb_db->ltdb->tdb, key);
 226 }
 227
 228 /*
 229   unlock a record in the ltdb, given a key
 230  */
 231 int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 232 {
 233         int ret = tdb_chainunlock(ctdb_db->ltdb->tdb, key);
 234         if (ret != 0) {
 235                 DEBUG(DEBUG_ERR,("tdb_chainunlock failed on db %s [%s]\n", ctdb_db->db_name, tdb_errorstr(ctdb_db->ltdb->tdb)));
 236         }
 237         return ret;
 238 }
 239
 240
 241 /*
 242   delete a record from a normal database
 243 */
 244 int ctdb_ltdb_delete(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 245 {
 246         if (ctdb_db->persistent != 0) {
 247                 DEBUG(DEBUG_ERR,("Trying to delete emty record in persistent database\n"));
 248                 return 0;
 249         }
 250         if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
 251                 DEBUG(DEBUG_ERR,("Failed to delete empty record."));
 252                 return -1;
 253         }
 254         return 0;
 255 }
 256
 257 int ctdb_trackingdb_add_pnn(struct ctdb_context *ctdb, TDB_DATA *data, uint32_t pnn)
 258 {
 259         int byte_pos = pnn / 8;
 260         int bit_mask   = 1 << (pnn % 8);
 261
 262         if (byte_pos + 1 > data->dsize) {
 263                 char *buf;
 264
 265                 buf = malloc(byte_pos + 1);
 266                 memset(buf, 0, byte_pos + 1);
 267                 if (buf == NULL) {
 268                         DEBUG(DEBUG_ERR, ("Out of memory when allocating buffer of %d bytes for trackingdb\n", byte_pos + 1));
 269                         return -1;
 270                 }
 271                 if (data->dptr != NULL) {
 272                         memcpy(buf, data->dptr, data->dsize);
 273                         free(data->dptr);
 274                 }
 275                 data->dptr  = (uint8_t *)buf;
 276                 data->dsize = byte_pos + 1;
 277         }
 278
 279         data->dptr[byte_pos] |= bit_mask;
 280         return 0;
 281 }
 282
 283 void ctdb_trackingdb_traverse(struct ctdb_context *ctdb, TDB_DATA data, ctdb_trackingdb_cb cb, void *private_data)
 284 {
 285         int i;
 286
 287         for(i = 0; i < data.dsize; i++) {
 288                 int j;
 289
 290                 for (j=0; j<8; j++) {
 291                         int mask = 1<<j;
 292
 293                         if (data.dptr[i] & mask) {
 294                                 cb(ctdb, i * 8 + j, private_data);
 295                         }
 296                 }
 297         }
 298 }
 299
 300 /*
 301   this is the dummy null procedure that all databases support
 302 */
 303 int ctdb_null_func(struct ctdb_call_info *call)
 304 {
 305         return 0;
 306 }
 307
 308 /*
 309   this is a plain fetch procedure that all databases support
 310 */
 311 int ctdb_fetch_func(struct ctdb_call_info *call)
 312 {
 313         call->reply_data = &call->record_data;
 314         return 0;
 315 }
 316
 317 /*
 318   this is a plain fetch procedure that all databases support
 319   this returns the full record including the ltdb header
 320 */
 321 int ctdb_fetch_with_header_func(struct ctdb_call_info *call)
 322 {
 323         call->reply_data = talloc(call, TDB_DATA);
 324         if (call->reply_data == NULL) {
 325                 return -1;
 326         }
 327         call->reply_data->dsize = sizeof(struct ctdb_ltdb_header) + call->record_data.dsize;
 328         call->reply_data->dptr  = talloc_size(call->reply_data, call->reply_data->dsize);
 329         if (call->reply_data->dptr == NULL) {
 330                 return -1;
 331         }
 332         memcpy(call->reply_data->dptr, call->header, sizeof(struct ctdb_ltdb_header));
 333         memcpy(&call->reply_data->dptr[sizeof(struct ctdb_ltdb_header)], call->record_data.dptr, call->record_data.dsize);
 334
 335         return 0;
 336 }
 337