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 "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 }
  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                 TDB_DATA d2;
  87                 /* return an initial header */
  88                 if (rec.dptr) free(rec.dptr);
  89                 if (ctdb->vnn_map == NULL) {
  90                         /* called from the client */
  91                         ZERO_STRUCTP(data);
  92                         header->dmaster = (uint32_t)-1;
  93                         return -1;
  94                 }
  95                 ltdb_initial_header(ctdb_db, key, header);
  96                 ZERO_STRUCT(d2);
  97                 if (data) {
  98                         *data = d2;
  99                 }
 100                 if (ctdb_db->persistent || header->dmaster == ctdb_db->ctdb->pnn) {
 101                         if (ctdb_ltdb_store(ctdb_db, key, header, d2) != 0) {
 102                                 DEBUG(DEBUG_NOTICE,
 103                                       (__location__ "failed to store initial header\n"));
 104                         }
 105                 }
 106                 return 0;
 107         }
 108
 109         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 110
 111         if (data) {
 112                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 113                 data->dptr = talloc_memdup(mem_ctx,
 114                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 115                                            data->dsize);
 116         }
 117
 118         free(rec.dptr);
 119         if (data) {
 120                 CTDB_NO_MEMORY(ctdb, data->dptr);
 121         }
 122
 123         return 0;
 124 }
 125
 126 /*
 127   fetch a record from the ltdb, separating out the header information
 128   and returning the body of the record.
 129   if the record does not exist, *header will be NULL
 130   and data = {0, NULL}
 131 */
 132 int ctdb_ltdb_fetch_with_header(struct ctdb_db_context *ctdb_db,
 133                     TDB_DATA key, struct ctdb_ltdb_header *header,
 134                     TALLOC_CTX *mem_ctx, TDB_DATA *data)
 135 {
 136         TDB_DATA rec;
 137
 138         rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 139         if (rec.dsize < sizeof(*header)) {
 140                 free(rec.dptr);
 141
 142                 data->dsize = 0;
 143                 data->dptr = NULL;
 144                 return -1;
 145         }
 146
 147         *header = *(struct ctdb_ltdb_header *)rec.dptr;
 148         if (data) {
 149                 data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
 150                 data->dptr = talloc_memdup(mem_ctx,
 151                                            sizeof(struct ctdb_ltdb_header)+rec.dptr,
 152                                            data->dsize);
 153         }
 154
 155         free(rec.dptr);
 156
 157         return 0;
 158 }
 159
 160
 161 /*
 162   write a record to a normal database
 163 */
 164 int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key,
 165                     struct ctdb_ltdb_header *header, TDB_DATA data)
 166 {
 167         struct ctdb_context *ctdb = ctdb_db->ctdb;
 168         TDB_DATA rec;
 169         int ret;
 170         bool seqnum_suppressed = false;
 171
 172         if (ctdb_db->ctdb_ltdb_store_fn) {
 173                 return ctdb_db->ctdb_ltdb_store_fn(ctdb_db, key, header, data);
 174         }
 175
 176         if (ctdb->flags & CTDB_FLAG_TORTURE) {
 177                 struct ctdb_ltdb_header *h2;
 178                 rec = tdb_fetch(ctdb_db->ltdb->tdb, key);
 179                 h2 = (struct ctdb_ltdb_header *)rec.dptr;
 180                 if (rec.dptr && rec.dsize >= sizeof(h2) && h2->rsn > header->rsn) {
 181                         DEBUG(DEBUG_CRIT,("RSN regression! %llu %llu\n",
 182                                  (unsigned long long)h2->rsn, (unsigned long long)header->rsn));
 183                 }
 184                 if (rec.dptr) free(rec.dptr);
 185         }
 186
 187         rec.dsize = sizeof(*header) + data.dsize;
 188         rec.dptr = talloc_size(ctdb, rec.dsize);
 189         CTDB_NO_MEMORY(ctdb, rec.dptr);
 190
 191         memcpy(rec.dptr, header, sizeof(*header));
 192         memcpy(rec.dptr + sizeof(*header), data.dptr, data.dsize);
 193
 194         /* Databases with seqnum updates enabled only get their seqnum
 195            changes when/if we modify the data */
 196         if (ctdb_db->seqnum_update != NULL) {
 197                 TDB_DATA old;
 198                 old = tdb_fetch(ctdb_db->ltdb->tdb, key);
 199
 200                 if ( (old.dsize == rec.dsize)
 201                 && !memcmp(old.dptr+sizeof(struct ctdb_ltdb_header),
 202                           rec.dptr+sizeof(struct ctdb_ltdb_header),
 203                           rec.dsize-sizeof(struct ctdb_ltdb_header)) ) {
 204                         tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 205                         seqnum_suppressed = true;
 206                 }
 207                 if (old.dptr) free(old.dptr);
 208         }
 209         ret = tdb_store(ctdb_db->ltdb->tdb, key, rec, TDB_REPLACE);
 210         if (ret != 0) {
 211                 DEBUG(DEBUG_ERR, (__location__ " Failed to store dynamic data\n"));
 212         }
 213         if (seqnum_suppressed) {
 214                 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_SEQNUM);
 215         }
 216
 217         talloc_free(rec.dptr);
 218
 219         return ret;
 220 }
 221
 222 /*
 223   lock a record in the ltdb, given a key
 224  */
 225 int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 226 {
 227         return tdb_chainlock(ctdb_db->ltdb->tdb, key);
 228 }
 229
 230 /*
 231   unlock a record in the ltdb, given a key
 232  */
 233 int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 234 {
 235         int ret = tdb_chainunlock(ctdb_db->ltdb->tdb, key);
 236         if (ret != 0) {
 237                 DEBUG(DEBUG_ERR,("tdb_chainunlock failed on db %s [%s]\n", ctdb_db->db_name, tdb_errorstr(ctdb_db->ltdb->tdb)));
 238         }
 239         return ret;
 240 }
 241
 242
 243 /*
 244   delete a record from a normal database
 245 */
 246 int ctdb_ltdb_delete(struct ctdb_db_context *ctdb_db, TDB_DATA key)
 247 {
 248         if (ctdb_db->persistent != 0) {
 249                 DEBUG(DEBUG_ERR,("Trying to delete emty record in persistent database\n"));
 250                 return 0;
 251         }
 252         if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
 253                 DEBUG(DEBUG_ERR,("Failed to delete empty record."));
 254                 return -1;
 255         }
 256         return 0;
 257 }
 258
 259 int ctdb_trackingdb_add_pnn(struct ctdb_context *ctdb, TDB_DATA *data, uint32_t pnn)
 260 {
 261         int byte_pos = pnn / 8;
 262         int bit_mask   = 1 << (pnn % 8);
 263
 264         if (byte_pos + 1 > data->dsize) {
 265                 char *buf;
 266
 267                 buf = malloc(byte_pos + 1);
 268                 memset(buf, 0, byte_pos + 1);
 269                 if (buf == NULL) {
 270                         DEBUG(DEBUG_ERR, ("Out of memory when allocating buffer of %d bytes for trackingdb\n", byte_pos + 1));
 271                         return -1;
 272                 }
 273                 if (data->dptr != NULL) {
 274                         memcpy(buf, data->dptr, data->dsize);
 275                         free(data->dptr);
 276                 }
 277                 data->dptr  = (uint8_t *)buf;
 278                 data->dsize = byte_pos + 1;
 279         }
 280
 281         data->dptr[byte_pos] |= bit_mask;
 282         return 0;
 283 }
 284
 285 void ctdb_trackingdb_traverse(struct ctdb_context *ctdb, TDB_DATA data, ctdb_trackingdb_cb cb, void *private_data)
 286 {
 287         int i;
 288
 289         for(i = 0; i < data.dsize; i++) {
 290                 int j;
 291
 292                 for (j=0; j<8; j++) {
 293                         int mask = 1<<j;
 294
 295                         if (data.dptr[i] & mask) {
 296                                 cb(ctdb, i * 8 + j, private_data);
 297                         }
 298                 }
 299         }
 300 }
 301
 302 /*
 303   this is the dummy null procedure that all databases support
 304 */
 305 int ctdb_null_func(struct ctdb_call_info *call)
 306 {
 307         return 0;
 308 }
 309
 310 /*
 311   this is a plain fetch procedure that all databases support
 312 */
 313 int ctdb_fetch_func(struct ctdb_call_info *call)
 314 {
 315         call->reply_data = &call->record_data;
 316         return 0;
 317 }
 318
 319 /*
 320   this is a plain fetch procedure that all databases support
 321   this returns the full record including the ltdb header
 322 */
 323 int ctdb_fetch_with_header_func(struct ctdb_call_info *call)
 324 {
 325         call->reply_data = talloc(call, TDB_DATA);
 326         if (call->reply_data == NULL) {
 327                 return -1;
 328         }
 329         call->reply_data->dsize = sizeof(struct ctdb_ltdb_header) + call->record_data.dsize;
 330         call->reply_data->dptr  = talloc_size(call->reply_data, call->reply_data->dsize);
 331         if (call->reply_data->dptr == NULL) {
 332                 return -1;
 333         }
 334         memcpy(call->reply_data->dptr, call->header, sizeof(struct ctdb_ltdb_header));
 335         memcpy(&call->reply_data->dptr[sizeof(struct ctdb_ltdb_header)], call->record_data.dptr, call->record_data.dsize);
 336
 337         return 0;
 338 }
 339