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   find an attached ctdb_db handle given a name
  38  */
  39 struct ctdb_db_context *ctdb_db_handle(struct ctdb_context *ctdb, const char *name)
  40 {
  41         struct ctdb_db_context *tmp_db;
  42         for (tmp_db=ctdb->db_list;tmp_db;tmp_db=tmp_db->next) {
  43                 if (strcmp(name, tmp_db->db_name) == 0) {
  44                         return tmp_db;
  45                 }
  46         }
  47         return NULL;
  48 }
  49
  50
  51 /*
  52   return the lmaster given a key
  53 */
  54 uint32_t ctdb_lmaster(struct ctdb_context *ctdb, const TDB_DATA *key)
  55 {
  56         uint32_t idx, lmaster;
  57
  58         idx = ctdb_hash(key) % ctdb->vnn_map->size;
  59         lmaster = ctdb->vnn_map->map[idx];
  60
  61         return lmaster;
  62 }
  63
  64
  65 /*
  66   construct an initial header for a record with no ltdb header yet
  67 */
  68 static void ltdb_initial_header(struct ctdb_db_context *ctdb_db,
  69                                 TDB_DATA key,
  70                                 struct ctdb_ltdb_header *header)
  71 {
  72         ZERO_STRUCTP(header);
  73         /* initial dmaster is the lmaster */
  74         header->dmaster = ctdb_lmaster(ctdb_db->ctdb, &key);
  75         header->flags = CTDB_REC_FLAG_AUTOMATIC;
  76 }
  77
  78
  79 /*
  80   fetch a record from the ltdb, separating out the header information
  81   and returning the body of the record. A valid (initial) header is
  82   returned if the record is not present
  83 */
  84 int ctdb_ltdb_fetch(struct ctdb_db_context *ctdb_db,
  85                     TDB_DATA key, struct ctdb_ltdb_header *header,
  86                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
  87 {
  88         TDB_DATA rec;
  89         struct ctdb_context *ctdb = ctdb_db->ctdb;
  90
  91         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
  92         if (rec.dsize < sizeof(*header)) {
  93                 /* return an initial header */
  94                 if (rec.dptr) free(rec.dptr);
  95                 if (ctdb->vnn_map == NULL) {
  96                         /* called from the client */
  97                         ZERO_STRUCTP(data);
  98                         header->dmaster = (uint32_t)-1;
  99                         return -1;
 100                 }
 101                 ltdb_initial_header(ctdb_db, key, header);
 102                 if (data) {
 103                         *data = tdb_null;
 104                 }
 105                 if (ctdb_db->persistent || header->dmaster == ctdb_db->ctdb->pnn) {
 106                         if (ctdb_ltdb_store(ctdb_db, key, header, tdb_null) != 0) {
 107                                 DEBUG(DEBUG_NOTICE,
 108                                       (__location__ "failed to store initial header\n"));
 109                         }
 110                 }
 111                 return 0;
 112         }
 113
 114         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 115
 116         if (data) {
 117                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 118                 data->dptr = talloc_memdup(mem_ctx,
 119                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 120                                            data->dsize);
 121         }
 122
 123         free(rec.dptr);
 124         if (data) {
 125                 CTDB_NO_MEMORY(ctdb, data->dptr);
 126         }
 127
 128         return 0;
 129 }
 130
 131 /*
 132   fetch a record from the ltdb, separating out the header information
 133   and returning the body of the record.
 134   if the record does not exist, *header will be NULL
 135   and data = {0, NULL}
 136 */
 137 int ctdb_ltdb_fetch_with_header(struct ctdb_db_context *ctdb_db,
 138                     TDB_DATA key, struct ctdb_ltdb_header *header,
 139                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
 140 {
 141         TDB_DATA rec;
 142
 143         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 144         if (rec.dsize < sizeof(*header)) {
 145                 free(rec.dptr);
 146
 147                 data->dsize = 0;
 148                 data->dptr = NULL;
 149                 return -1;
 150         }
 151
 152         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 153         if (data) {
 154                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 155                 data->dptr = talloc_memdup(mem_ctx,
 156                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 157                                            data->dsize);
 158         }
 159
 160         free(rec.dptr);
 161
 162         return 0;
 163 }
 164
 165
 166 /*
 167   write a record to a normal database
 168 */
 169 int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key,
 170                     struct ctdb_ltdb_header *header, TDB_DATA data)
 171 {
 172         struct ctdb_context *ctdb = ctdb_db->ctdb;
 173         TDB_DATA rec[2];
 174         uint32_t hsize = sizeof(struct ctdb_ltdb_header);
 175         int ret;
 176         bool seqnum_suppressed = false;
 177
 178         if (ctdb_db->ctdb_ltdb_store_fn) {
 179                 return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data);
 180         }
 181
 182         if (ctdb->flags & CTDB_FLAG_TORTURE) {
 183                 TDB_DATA old;
 184                 struct ctdb_ltdb_header *h2;
 185
 186                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 187                 h2 = (struct ctdb_ltdb_header *)old.dptr;
 188                 if (old.dptr != NULL && old.dsize >= hsize &&
 189                     h2->rsn > header->rsn) {
 190                         DEBUG(DEBUG_ERR,
 191                               ("RSN regression! %"PRIu64" %"PRIu64"\n",
 192                                h2->rsn, header->rsn));
 193                 }
 194                 if (old.dptr != NULL) {
 195                         free(old.dptr);
 196                 }
 197         }
 198
 199         rec[0].dsize = hsize;
 200         rec[0].dptr = (uint8_t *)header;
 201
 202         rec[1].dsize = data.dsize;
 203         rec[1].dptr = data.dptr;
 204
 205         /* Databases with seqnum updates enabled only get their seqnum
 206            changes when/if we modify the data */
 207         if (ctdb_db->seqnum_update != NULL) {
 208                 TDB_DATA old;
 209                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 210
 211                 if ((old.dsize == hsize + data.dsize) &&
 212                     memcmp(old.dptr+hsize, data.dptr, data.dsize) == 0) {
 213                         tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 214                         seqnum_suppressed = true;
 215                 }
 216                 if (old.dptr != NULL) {
 217                         free(old.dptr);
 218                 }
 219         }
 220         ret = tdb_storev(ctdb_db->ltdb->tdb, key, rec, 2, TDB_REPLACE);
 221         if (ret != 0) {
 222                 DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n"));
 223         }
 224         if (seqnum_suppressed) {
 225                 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 226         }
 227
 228         return ret;
 229 }
 230
 231 /*
 232   lock a record in the ltdb, given a key
 233  */
 234 int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 235 {
 236         return tdb_chainlock(ctdb_db->ltdb->tdb, key);
 237 }
 238
 239 /*
 240   unlock a record in the ltdb, given a key
 241  */
 242 int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 243 {
 244         int ret = tdb_chainunlock(ctdb_db->ltdb->tdb, key);
 245         if (ret != 0) {
 246                 DEBUG(DEBUG_ERR,("tdb_chainunlock failed on db %s [%s]\n", ctdb_db->db_name, tdb_errorstr(ctdb_db->ltdb->tdb)));
 247         }
 248         return ret;
 249 }
 250
 251
 252 /*
 253   delete a record from a normal database
 254 */
 255 int ctdb_ltdb_delete(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 256 {
 257         if (ctdb_db->persistent != 0) {
 258                 DEBUG(DEBUG_ERR,("Trying to delete empty record in persistent database\n"));
 259                 return 0;
 260         }
 261         if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
 262                 DEBUG(DEBUG_ERR,("Failed to delete empty record."));
 263                 return -1;
 264         }
 265         return 0;
 266 }
 267
 268 int ctdb_trackingdb_add_pnn(struct ctdb_context *ctdb, TDB_DATA *data, uint32_t pnn)
 269 {
 270         int byte_pos = pnn / 8;
 271         int bit_mask   = 1 << (pnn % 8);
 272
 273         if (byte_pos + 1 > data->dsize) {
 274                 char *buf;
 275
 276                 buf = malloc(byte_pos + 1);
 277                 memset(buf, 0, byte_pos + 1);
 278                 if (buf == NULL) {
 279                         DEBUG(DEBUG_ERR, ("Out of memory when allocating buffer of %d bytes for trackingdb\n", byte_pos + 1));
 280                         return -1;
 281                 }
 282                 if (data->dptr != NULL) {
 283                         memcpy(buf, data->dptr, data->dsize);
 284                         free(data->dptr);
 285                 }
 286                 data->dptr  = (uint8_t *)buf;
 287                 data->dsize = byte_pos + 1;
 288         }
 289
 290         data->dptr[byte_pos] |= bit_mask;
 291         return 0;
 292 }
 293
 294 void ctdb_trackingdb_traverse(struct ctdb_context *ctdb, TDB_DATA data, ctdb_trackingdb_cb cb, void *private_data)
 295 {
 296         int i;
 297
 298         for(i = 0; i < data.dsize; i++) {
 299                 int j;
 300
 301                 for (j=0; j<8; j++) {
 302                         int mask = 1<<j;
 303
 304                         if (data.dptr[i] & mask) {
 305                                 cb(ctdb, i * 8 + j, private_data);
 306                         }
 307                 }
 308         }
 309 }
 310
 311 /*
 312   this is the dummy null procedure that all databases support
 313 */
 314 int ctdb_null_func(struct ctdb_call_info *call)
 315 {
 316         return 0;
 317 }
 318
 319 /*
 320   this is a plain fetch procedure that all databases support
 321 */
 322 int ctdb_fetch_func(struct ctdb_call_info *call)
 323 {
 324         call->reply_data = &call->record_data;
 325         return 0;
 326 }
 327
 328 /*
 329   this is a plain fetch procedure that all databases support
 330   this returns the full record including the ltdb header
 331 */
 332 int ctdb_fetch_with_header_func(struct ctdb_call_info *call)
 333 {
 334         call->reply_data = talloc(call, TDB_DATA);
 335         if (call->reply_data == NULL) {
 336                 return -1;
 337         }
 338         call->reply_data->dsize = sizeof(struct ctdb_ltdb_header) + call->record_data.dsize;
 339         call->reply_data->dptr  = talloc_size(call->reply_data, call->reply_data->dsize);
 340         if (call->reply_data->dptr == NULL) {
 341                 return -1;
 342         }
 343         memcpy(call->reply_data->dptr, call->header, sizeof(struct ctdb_ltdb_header));
 344         memcpy(&call->reply_data->dptr[sizeof(struct ctdb_ltdb_header)], call->record_data.dptr, call->record_data.dsize);
 345
 346         return 0;
 347 }
 348