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 "lib/tdb/include/tdb.h"
  23 #include "system/network.h"
  24 #include "system/filesys.h"
  25 #include "../include/ctdb_private.h"
  26 #include "db_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         header->laccessor = header->dmaster;
  70 }
  71
  72
  73 /*
  74   fetch a record from the ltdb, separating out the header information
  75   and returning the body of the record. A valid (initial) header is
  76   returned if the record is not present
  77 */
  78 int ctdb_ltdb_fetch(struct ctdb_db_context *ctdb_db,
  79                     TDB_DATA key, struct ctdb_ltdb_header *header,
  80                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
  81 {
  82         TDB_DATA rec;
  83         struct ctdb_context *ctdb = ctdb_db->ctdb;
  84
  85         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
  86         if (rec.dsize < sizeof(*header)) {
  87                 TDB_DATA d2;
  88                 /* return an initial header */
  89                 if (rec.dptr) free(rec.dptr);
  90                 if (ctdb->vnn_map == NULL) {
  91                         /* called from the client */
  92                         ZERO_STRUCTP(data);
  93                         header->dmaster = (uint32_t)-1;
  94                         return -1;
  95                 }
  96                 ltdb_initial_header(ctdb_db, key, header);
  97                 ZERO_STRUCT(d2);
  98                 if (data) {
  99                         *data = d2;
 100                 }
 101                 ctdb_ltdb_store(ctdb_db, key, header, d2);
 102                 return 0;
 103         }
 104
 105         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 106
 107         if (data) {
 108                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 109                 data->dptr = talloc_memdup(mem_ctx,
 110                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 111                                            data->dsize);
 112         }
 113
 114         free(rec.dptr);
 115         if (data) {
 116                 CTDB_NO_MEMORY(ctdb, data->dptr);
 117         }
 118
 119         return 0;
 120 }
 121
 122 /*
 123   fetch a record from the ltdb, separating out the header information
 124   and returning the body of the record.
 125   if the record does not exist, *header will be NULL
 126   and data = {0, NULL}
 127 */
 128 int ctdb_ltdb_fetch_with_header(struct ctdb_db_context *ctdb_db,
 129                     TDB_DATA key, struct ctdb_ltdb_header *header,
 130                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
 131 {
 132         TDB_DATA rec;
 133
 134         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 135         if (rec.dsize < sizeof(*header)) {
 136                 free(rec.dptr);
 137
 138                 data->dsize = 0;
 139                 data->dptr = NULL;
 140                 return -1;
 141         }
 142
 143         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 144         if (data) {
 145                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 146                 data->dptr = talloc_memdup(mem_ctx,
 147                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 148                                            data->dsize);
 149         }
 150
 151         free(rec.dptr);
 152
 153         return 0;
 154 }
 155
 156
 157 /*
 158   write a record to a normal database
 159 */
 160 int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key,
 161                     struct ctdb_ltdb_header *header, TDB_DATA data)
 162 {
 163         struct ctdb_context *ctdb = ctdb_db->ctdb;
 164         TDB_DATA rec;
 165         int ret;
 166         bool seqnum_suppressed = false;
 167
 168         if (ctdb_db->ctdb_ltdb_store_fn) {
 169                 return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data);
 170         }
 171
 172         if (ctdb->flags & CTDB_FLAG_TORTURE) {
 173                 struct ctdb_ltdb_header *h2;
 174                 rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 175                 h2 = (struct ctdb_ltdb_header *)rec.dptr;
 176                 if (rec.dptr && rec.dsize >= sizeof(h2) && h2->rsn > header->rsn) {
 177                         DEBUG(DEBUG_CRIT,("RSN regression! %llu %llu\n",
 178                                  (unsigned long long)h2->rsn, (unsigned long long)header->rsn));
 179                 }
 180                 if (rec.dptr) free(rec.dptr);
 181         }
 182
 183         rec.dsize = sizeof(*header) + data.dsize;
 184         rec.dptr = talloc_size(ctdb, rec.dsize);
 185         CTDB_NO_MEMORY(ctdb, rec.dptr);
 186
 187         memcpy(rec.dptr, header, sizeof(*header));
 188         memcpy(rec.dptr + sizeof(*header), data.dptr, data.dsize);
 189
 190         /* Databases with seqnum updates enabled only get their seqnum
 191            changes when/if we modify the data */
 192         if (ctdb_db->seqnum_update != NULL) {
 193                 TDB_DATA old;
 194                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 195
 196                 if ( (old.dsize == rec.dsize)
 197                 && !memcmp(old.dptr+sizeof(struct ctdb_ltdb_header),
 198                           rec.dptr+sizeof(struct ctdb_ltdb_header),
 199                           rec.dsize-sizeof(struct ctdb_ltdb_header)) ) {
 200                         tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 201                         seqnum_suppressed = true;
 202                 }
 203                 if (old.dptr) free(old.dptr);
 204         }
 205         ret = tdb_store(ctdb_db->ltdb->tdb, key, rec, TDB_REPLACE);
 206         if (ret != 0) {
 207                 DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n"));
 208         }
 209         if (seqnum_suppressed) {
 210                 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 211         }
 212
 213         talloc_free(rec.dptr);
 214
 215         return ret;
 216 }
 217
 218 /*
 219   lock a record in the ltdb, given a key
 220  */
 221 int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 222 {
 223         return tdb_chainlock(ctdb_db->ltdb->tdb, key);
 224 }
 225
 226 /*
 227   unlock a record in the ltdb, given a key
 228  */
 229 int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 230 {
 231         int ret = tdb_chainunlock(ctdb_db->ltdb->tdb, key);
 232         if (ret != 0) {
 233                 DEBUG(DEBUG_ERR,("tdb_chainunlock failed on db %s [%s]\n", ctdb_db->db_name, tdb_errorstr(ctdb_db->ltdb->tdb)));
 234         }
 235         return ret;
 236 }
 237
 238
 239 /*
 240   delete a record from a normal database
 241 */
 242 int ctdb_ltdb_delete(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 243 {
 244         if (ctdb_db->persistent != 0) {
 245                 DEBUG(DEBUG_ERR,("Trying to delete emty record in persistent database\n"));
 246                 return 0;
 247         }
 248         if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
 249                 DEBUG(DEBUG_ERR,("Failed to delete empty record."));
 250                 return -1;
 251         }
 252         return 0;
 253 }
 254
 255 int ctdb_trackingdb_add_pnn(struct ctdb_context *ctdb, TDB_DATA *data, uint32_t pnn)
 256 {
 257         int byte_pos = pnn / 8;
 258         int bit_mask   = 1 << (pnn % 8);
 259
 260         if (byte_pos + 1 > data->dsize) {
 261                 char *buf;
 262
 263                 buf = malloc(byte_pos + 1);
 264                 memset(buf, 0, byte_pos + 1);
 265                 if (buf == NULL) {
 266                         DEBUG(DEBUG_ERR, ("Out of memory when allocating buffer of %d bytes for trackingdb\n", byte_pos + 1));
 267                         return -1;
 268                 }
 269                 if (data->dptr != NULL) {
 270                         memcpy(buf, data->dptr, data->dsize);
 271                         free(data->dptr);
 272                 }
 273                 data->dptr  = (uint8_t *)buf;
 274                 data->dsize = byte_pos + 1;
 275         }
 276
 277         data->dptr[byte_pos] |= bit_mask;
 278         return 0;
 279 }
 280
 281 void ctdb_trackingdb_traverse(struct ctdb_context *ctdb, TDB_DATA data, ctdb_trackingdb_cb cb, void *private_data)
 282 {
 283         int i;
 284
 285         for(i = 0; i < data.dsize; i++) {
 286                 int j;
 287
 288                 for (j=0; j<8; j++) {
 289                         int mask = 1<<j;
 290
 291                         if (data.dptr[i] & mask) {
 292                                 cb(ctdb, i * 8 + j, private_data);
 293                         }
 294                 }
 295         }
 296 }
 297
 298 /*
 299   this is the dummy null procedure that all databases support
 300 */
 301 int ctdb_null_func(struct ctdb_call_info *call)
 302 {
 303         return 0;
 304 }
 305
 306 /*
 307   this is a plain fetch procedure that all databases support
 308 */
 309 int ctdb_fetch_func(struct ctdb_call_info *call)
 310 {
 311         call->reply_data = &call->record_data;
 312         return 0;
 313 }
 314
 315 /*
 316   this is a plain fetch procedure that all databases support
 317   this returns the full record including the ltdb header
 318 */
 319 int ctdb_fetch_with_header_func(struct ctdb_call_info *call)
 320 {
 321         call->reply_data = talloc(call, TDB_DATA);
 322         if (call->reply_data == NULL) {
 323                 return -1;
 324         }
 325         call->reply_data->dsize = sizeof(struct ctdb_ltdb_header) + call->record_data.dsize;
 326         call->reply_data->dptr  = talloc_size(call->reply_data, call->reply_data->dsize);
 327         if (call->reply_data->dptr == NULL) {
 328                 return -1;
 329         }
 330         memcpy(call->reply_data->dptr, call->header, sizeof(struct ctdb_ltdb_header));
 331         memcpy(&call->reply_data->dptr[sizeof(struct ctdb_ltdb_header)], call->record_data.dptr, call->record_data.dsize);
 332
 333         return 0;
 334 }
 335