source/locking/locking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Locking functions
   4    Copyright (C) Andrew Tridgell 1992-2000
   5    Copyright (C) Jeremy Allison 1992-2000
   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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21    Revision History:
  22
  23    12 aug 96: Erik.Devriendt@te6.siemens.be
  24    added support for shared memory implementation of share mode locking
  25
  26    May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
  27    locking to deal with multiple share modes per open file.
  28
  29    September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
  30    support.
  31
  32    rewrtten completely to use new tdb code. Tridge, Dec '99
  33
  34    Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
  35 */
  36
  37 #include "includes.h"
  38 uint16 global_smbpid;
  39
  40 /* the locking database handle */
  41 static TDB_CONTEXT *tdb;
  42
  43 /****************************************************************************
  44  Debugging aid :-).
  45 ****************************************************************************/
  46
  47 static const char *lock_type_name(enum brl_type lock_type)
  48 {
  49         return (lock_type == READ_LOCK) ? "READ" : "WRITE";
  50 }
  51
  52 /****************************************************************************
  53  Utility function called to see if a file region is locked.
  54  If check_self is True, then checks on our own fd with the same locking context
  55  are still made. If check_self is False, then checks are not made on our own fd
  56  with the same locking context are not made.
  57 ****************************************************************************/
  58
  59 BOOL is_locked(files_struct *fsp,connection_struct *conn,
  60                SMB_BIG_UINT count,SMB_BIG_UINT offset,
  61                enum brl_type lock_type, BOOL check_self)
  62 {
  63         int snum = SNUM(conn);
  64         BOOL ret;
  65
  66         if (count == 0)
  67                 return(False);
  68
  69         if (!lp_locking(snum) || !lp_strict_locking(snum))
  70                 return(False);
  71
  72         ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
  73                              global_smbpid, sys_getpid(), conn->cnum,
  74                              offset, count, lock_type, check_self);
  75
  76         DEBUG(10,("is_locked: brl start=%.0f len=%.0f %s for file %s\n",
  77                         (double)offset, (double)count, ret ? "locked" : "unlocked",
  78                         fsp->fsp_name ));
  79
  80         /*
  81          * There is no lock held by an SMB daemon, check to
  82          * see if there is a POSIX lock from a UNIX or NFS process.
  83          */
  84
  85         if(!ret && lp_posix_locking(snum)) {
  86                 ret = is_posix_locked(fsp, offset, count, lock_type);
  87
  88                 DEBUG(10,("is_locked: posix start=%.0f len=%.0f %s for file %s\n",
  89                                 (double)offset, (double)count, ret ? "locked" : "unlocked",
  90                                 fsp->fsp_name ));
  91         }
  92
  93         return ret;
  94 }
  95
  96 /****************************************************************************
  97  Utility function called by locking requests.
  98 ****************************************************************************/
  99
 100 static NTSTATUS do_lock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 101                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type)
 102 {
 103         NTSTATUS status;
 104
 105         if (!lp_locking(SNUM(conn)))
 106                 return NT_STATUS_OK;
 107
 108         /* NOTE! 0 byte long ranges ARE allowed and should be stored  */
 109
 110
 111         DEBUG(10,("do_lock: lock type %s start=%.0f len=%.0f requested for file %s\n",
 112                   lock_type_name(lock_type), (double)offset, (double)count, fsp->fsp_name ));
 113
 114         if (OPEN_FSP(fsp) && fsp->can_lock && (fsp->conn == conn)) {
 115                 status = brl_lock(fsp->dev, fsp->inode, fsp->fnum,
 116                                   lock_pid, sys_getpid(), conn->cnum,
 117                                   offset, count,
 118                                   lock_type);
 119
 120                 if (NT_STATUS_IS_OK(status) && lp_posix_locking(SNUM(conn))) {
 121
 122                         /*
 123                          * Try and get a POSIX lock on this range.
 124                          * Note that this is ok if it is a read lock
 125                          * overlapping on a different fd. JRA.
 126                          */
 127
 128                         if (!set_posix_lock(fsp, offset, count, lock_type)) {
 129                                 status = NT_STATUS_LOCK_NOT_GRANTED;
 130                                 /*
 131                                  * We failed to map - we must now remove the brl
 132                                  * lock entry.
 133                                  */
 134                                 (void)brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 135                                                                 lock_pid, sys_getpid(), conn->cnum,
 136                                                                 offset, count);
 137                         }
 138                 }
 139         }
 140
 141         return status;
 142 }
 143
 144 /****************************************************************************
 145  Utility function called by locking requests. This is *DISGUSTING*. It also
 146  appears to be "What Windows Does" (tm). Andrew, ever wonder why Windows 2000
 147  is so slow on the locking tests...... ? This is the reason. Much though I hate
 148  it, we need this. JRA.
 149 ****************************************************************************/
 150
 151 NTSTATUS do_lock_spin(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 152                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type)
 153 {
 154         int j, maxj = lp_lock_spin_count();
 155         int sleeptime = lp_lock_sleep_time();
 156         NTSTATUS status, ret;
 157
 158         if (maxj <= 0)
 159                 maxj = 1;
 160
 161         ret = NT_STATUS_OK; /* to keep dumb compilers happy */
 162
 163         for (j = 0; j < maxj; j++) {
 164                 status = do_lock(fsp, conn, lock_pid, count, offset, lock_type);
 165                 if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED) &&
 166                     !NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 167                         return status;
 168                 }
 169                 /* if we do fail then return the first error code we got */
 170                 if (j == 0) {
 171                         ret = status;
 172                 }
 173                 if (sleeptime)
 174                         sys_usleep(sleeptime);
 175         }
 176         return ret;
 177 }
 178
 179 /****************************************************************************
 180  Utility function called by unlocking requests.
 181 ****************************************************************************/
 182
 183 NTSTATUS do_unlock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 184                    SMB_BIG_UINT count,SMB_BIG_UINT offset)
 185 {
 186         BOOL ok = False;
 187
 188         if (!lp_locking(SNUM(conn)))
 189                 return NT_STATUS_OK;
 190
 191         if (!OPEN_FSP(fsp) || !fsp->can_lock || (fsp->conn != conn)) {
 192                 return NT_STATUS_INVALID_HANDLE;
 193         }
 194
 195         DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for file %s\n",
 196                   (double)offset, (double)count, fsp->fsp_name ));
 197
 198         /*
 199          * Remove the existing lock record from the tdb lockdb
 200          * before looking at POSIX locks. If this record doesn't
 201          * match then don't bother looking to remove POSIX locks.
 202          */
 203
 204         ok = brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 205                         lock_pid, sys_getpid(), conn->cnum, offset, count);
 206
 207         if (!ok) {
 208                 DEBUG(10,("do_unlock: returning ERRlock.\n" ));
 209                 return NT_STATUS_RANGE_NOT_LOCKED;
 210         }
 211
 212         if (!lp_posix_locking(SNUM(conn)))
 213                 return NT_STATUS_OK;
 214
 215         (void)release_posix_lock(fsp, offset, count);
 216
 217         return NT_STATUS_OK;
 218 }
 219
 220 /****************************************************************************
 221  Remove any locks on this fd. Called from file_close().
 222 ****************************************************************************/
 223
 224 void locking_close_file(files_struct *fsp)
 225 {
 226         pid_t pid = sys_getpid();
 227
 228         if (!lp_locking(SNUM(fsp->conn)))
 229                 return;
 230
 231         /*
 232          * Just release all the brl locks, no need to release individually.
 233          */
 234
 235         brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum);
 236
 237         if(lp_posix_locking(SNUM(fsp->conn))) {
 238
 239                 /*
 240                  * Release all the POSIX locks.
 241                  */
 242                 posix_locking_close_file(fsp);
 243
 244         }
 245 }
 246
 247 /****************************************************************************
 248  Initialise the locking functions.
 249 ****************************************************************************/
 250
 251 static int open_read_only;
 252
 253 BOOL locking_init(int read_only)
 254 {
 255         brl_init(read_only);
 256
 257         if (tdb)
 258                 return True;
 259
 260         tdb = tdb_open_log(lock_path("locking.tdb"),
 261                        0, TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
 262                        read_only?O_RDONLY:O_RDWR|O_CREAT,
 263                        0644);
 264
 265         if (!tdb) {
 266                 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
 267                 return False;
 268         }
 269
 270         if (!posix_locking_init(read_only))
 271                 return False;
 272
 273         open_read_only = read_only;
 274
 275         return True;
 276 }
 277
 278 /*******************************************************************
 279  Deinitialize the share_mode management.
 280 ******************************************************************/
 281
 282 BOOL locking_end(void)
 283 {
 284
 285         brl_shutdown(open_read_only);
 286         if (tdb) {
 287
 288                 if (tdb_close(tdb) != 0)
 289                         return False;
 290         }
 291
 292         return True;
 293 }
 294
 295 /*******************************************************************
 296  Form a static locking key for a dev/inode pair.
 297 ******************************************************************/
 298
 299 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
 300 {
 301         static struct locking_key key;
 302         TDB_DATA kbuf;
 303
 304         memset(&key, '\0', sizeof(key));
 305         key.dev = dev;
 306         key.inode = inode;
 307         kbuf.dptr = (char *)&key;
 308         kbuf.dsize = sizeof(key);
 309         return kbuf;
 310 }
 311
 312 static TDB_DATA locking_key_fsp(files_struct *fsp)
 313 {
 314         return locking_key(fsp->dev, fsp->inode);
 315 }
 316
 317 /*******************************************************************
 318  Lock a hash bucket entry.
 319 ******************************************************************/
 320
 321 BOOL lock_share_entry(connection_struct *conn,
 322                       SMB_DEV_T dev, SMB_INO_T inode)
 323 {
 324         return tdb_chainlock(tdb, locking_key(dev, inode)) == 0;
 325 }
 326
 327 /*******************************************************************
 328  Unlock a hash bucket entry.
 329 ******************************************************************/
 330
 331 void unlock_share_entry(connection_struct *conn,
 332                         SMB_DEV_T dev, SMB_INO_T inode)
 333 {
 334         tdb_chainunlock(tdb, locking_key(dev, inode));
 335 }
 336
 337 /*******************************************************************
 338  Lock a hash bucket entry. use a fsp for convenience
 339 ******************************************************************/
 340
 341 BOOL lock_share_entry_fsp(files_struct *fsp)
 342 {
 343         return tdb_chainlock(tdb, locking_key(fsp->dev, fsp->inode)) == 0;
 344 }
 345
 346 /*******************************************************************
 347  Unlock a hash bucket entry.
 348 ******************************************************************/
 349
 350 void unlock_share_entry_fsp(files_struct *fsp)
 351 {
 352         tdb_chainunlock(tdb, locking_key(fsp->dev, fsp->inode));
 353 }
 354
 355 /*******************************************************************
 356  Print out a share mode.
 357 ********************************************************************/
 358
 359 static char *share_mode_str(int num, share_mode_entry *e)
 360 {
 361         static pstring share_str;
 362
 363         slprintf(share_str, sizeof(share_str)-1, "share_mode_entry[%d]: \
 364 pid = %u, share_mode = 0x%x, desired_access = 0x%x, port = 0x%x, type= 0x%x, file_id = %lu, dev = 0x%x, inode = %.0f",
 365         num, e->pid, e->share_mode, (unsigned int)e->desired_access, e->op_port, e->op_type, e->share_file_id,
 366         (unsigned int)e->dev, (double)e->inode );
 367
 368         return share_str;
 369 }
 370
 371 /*******************************************************************
 372  Print out a share mode table.
 373 ********************************************************************/
 374
 375 static void print_share_mode_table(struct locking_data *data)
 376 {
 377         int num_share_modes = data->u.num_share_mode_entries;
 378         share_mode_entry *shares = (share_mode_entry *)(data + 1);
 379         int i;
 380
 381         for (i = 0; i < num_share_modes; i++) {
 382                 share_mode_entry *entry_p = &shares[i];
 383                 DEBUG(10,("print_share_mode_table: %s\n", share_mode_str(i, entry_p) ));
 384         }
 385 }
 386
 387 /*******************************************************************
 388  Get all share mode entries for a dev/inode pair.
 389 ********************************************************************/
 390
 391 int get_share_modes(connection_struct *conn,
 392                     SMB_DEV_T dev, SMB_INO_T inode,
 393                     share_mode_entry **pp_shares)
 394 {
 395         TDB_DATA dbuf;
 396         struct locking_data *data;
 397         int num_share_modes;
 398         share_mode_entry *shares = NULL;
 399
 400         *pp_shares = NULL;
 401
 402         dbuf = tdb_fetch(tdb, locking_key(dev, inode));
 403         if (!dbuf.dptr)
 404                 return 0;
 405
 406         data = (struct locking_data *)dbuf.dptr;
 407         num_share_modes = data->u.num_share_mode_entries;
 408         if(num_share_modes) {
 409                 int i;
 410                 int del_count = 0;
 411
 412                 shares = (share_mode_entry *)memdup(dbuf.dptr + sizeof(*data),
 413                                                 num_share_modes * sizeof(share_mode_entry));
 414
 415                 if (!shares) {
 416                         SAFE_FREE(dbuf.dptr);
 417                         return 0;
 418                 }
 419
 420                 /*
 421                  * Ensure that each entry has a real process attached.
 422                  */
 423
 424                 for (i = 0; i < num_share_modes; ) {
 425                         share_mode_entry *entry_p = &shares[i];
 426                         if (process_exists(entry_p->pid)) {
 427                                 DEBUG(10,("get_share_modes: %s\n", share_mode_str(i, entry_p) ));
 428                                 i++;
 429                         } else {
 430                                 DEBUG(10,("get_share_modes: deleted %s\n", share_mode_str(i, entry_p) ));
 431                                 memcpy( &shares[i], &shares[i+1],
 432                                         sizeof(share_mode_entry) * (num_share_modes - i - 1));
 433                                 num_share_modes--;
 434                                 del_count++;
 435                         }
 436                 }
 437
 438                 /* Did we delete any ? If so, re-store in tdb. */
 439                 if (del_count) {
 440                         data->u.num_share_mode_entries = num_share_modes;
 441
 442                         if (num_share_modes)
 443                                 memcpy(dbuf.dptr + sizeof(*data), shares,
 444                                                 num_share_modes * sizeof(share_mode_entry));
 445
 446                         /* The record has shrunk a bit */
 447                         dbuf.dsize -= del_count * sizeof(share_mode_entry);
 448
 449                         if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1) {
 450                                 SAFE_FREE(shares);
 451                                 SAFE_FREE(dbuf.dptr);
 452                                 return 0;
 453                         }
 454                 }
 455         }
 456
 457         SAFE_FREE(dbuf.dptr);
 458         *pp_shares = shares;
 459         return num_share_modes;
 460 }
 461
 462 /*******************************************************************
 463  Fill a share mode entry.
 464 ********************************************************************/
 465
 466 static void fill_share_mode(char *p, files_struct *fsp, uint16 port, uint16 op_type)
 467 {
 468         share_mode_entry *e = (share_mode_entry *)p;
 469         void *x = &e->time; /* Needed to force alignment. p may not be aligned.... */
 470
 471         memset(e, '\0', sizeof(share_mode_entry));
 472         e->pid = sys_getpid();
 473         e->share_mode = fsp->share_mode;
 474         e->desired_access = fsp->desired_access;
 475         e->op_port = port;
 476         e->op_type = op_type;
 477         memcpy(x, &fsp->open_time, sizeof(struct timeval));
 478         e->share_file_id = fsp->file_id;
 479         e->dev = fsp->dev;
 480         e->inode = fsp->inode;
 481 }
 482
 483 /*******************************************************************
 484  Check if two share mode entries are identical, ignoring oplock
 485  and port info and desired_access.
 486 ********************************************************************/
 487
 488 BOOL share_modes_identical( share_mode_entry *e1, share_mode_entry *e2)
 489 {
 490 #if 1 /* JRA PARANOIA TEST - REMOVE LATER */
 491         if (e1->pid == e2->pid &&
 492                 e1->share_file_id == e2->share_file_id &&
 493                 e1->dev == e2->dev &&
 494                 e1->inode == e2->inode &&
 495                 (e1->share_mode & ~DELETE_ON_CLOSE_FLAG) != (e2->share_mode & ~DELETE_ON_CLOSE_FLAG)) {
 496                         DEBUG(0,("PANIC: share_modes_identical: share_mode missmatch (e1 = %u, e2 = %u). Logic error.\n",
 497                                 (unsigned int)(e1->share_mode & ~DELETE_ON_CLOSE_FLAG),
 498                                 (unsigned int)(e2->share_mode & ~DELETE_ON_CLOSE_FLAG) ));
 499                 smb_panic("PANIC: share_modes_identical logic error.\n");
 500         }
 501 #endif
 502
 503         return (e1->pid == e2->pid &&
 504                 (e1->share_mode & ~DELETE_ON_CLOSE_FLAG) == (e2->share_mode & ~DELETE_ON_CLOSE_FLAG) &&
 505                 e1->dev == e2->dev &&
 506                 e1->inode == e2->inode &&
 507                 e1->share_file_id == e2->share_file_id );
 508 }
 509
 510 /*******************************************************************
 511  Delete a specific share mode. Return the number
 512  of entries left, and a memdup'ed copy of the entry deleted (if required).
 513  Ignore if no entry deleted.
 514 ********************************************************************/
 515
 516 ssize_t del_share_entry( SMB_DEV_T dev, SMB_INO_T inode,
 517                         share_mode_entry *entry, share_mode_entry **ppse)
 518 {
 519         TDB_DATA dbuf;
 520         struct locking_data *data;
 521         int i, del_count=0;
 522         share_mode_entry *shares;
 523         ssize_t count = 0;
 524
 525         if (ppse)
 526                 *ppse = NULL;
 527
 528         /* read in the existing share modes */
 529         dbuf = tdb_fetch(tdb, locking_key(dev, inode));
 530         if (!dbuf.dptr)
 531                 return -1;
 532
 533         data = (struct locking_data *)dbuf.dptr;
 534         shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
 535
 536         /*
 537          * Find any with this pid and delete it
 538          * by overwriting with the rest of the data
 539          * from the record.
 540          */
 541
 542         DEBUG(10,("del_share_entry: num_share_modes = %d\n", data->u.num_share_mode_entries ));
 543
 544         for (i=0;i<data->u.num_share_mode_entries;) {
 545                 if (share_modes_identical(&shares[i], entry)) {
 546                         DEBUG(10,("del_share_entry: deleted %s\n",
 547                                 share_mode_str(i, &shares[i]) ));
 548                         if (ppse)
 549                                 *ppse = memdup(&shares[i], sizeof(*shares));
 550                         data->u.num_share_mode_entries--;
 551                         memmove(&shares[i], &shares[i+1],
 552                                 dbuf.dsize - (sizeof(*data) + (i+1)*sizeof(*shares)));
 553                         del_count++;
 554
 555                         DEBUG(10,("del_share_entry: deleting entry %d\n", i ));
 556
 557                 } else {
 558                         i++;
 559                 }
 560         }
 561
 562         if (del_count) {
 563                 /* the record may have shrunk a bit */
 564                 dbuf.dsize -= del_count * sizeof(*shares);
 565
 566                 count = (ssize_t)data->u.num_share_mode_entries;
 567
 568                 /* store it back in the database */
 569                 if (data->u.num_share_mode_entries == 0) {
 570                         if (tdb_delete(tdb, locking_key(dev, inode)) == -1)
 571                                 count = -1;
 572                 } else {
 573                         if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1)
 574                                 count = -1;
 575                 }
 576         }
 577         DEBUG(10,("del_share_entry: Remaining table.\n"));
 578         print_share_mode_table((struct locking_data *)dbuf.dptr);
 579         SAFE_FREE(dbuf.dptr);
 580         return count;
 581 }
 582
 583 /*******************************************************************
 584  Del the share mode of a file for this process. Return the number
 585  of entries left, and a memdup'ed copy of the entry deleted.
 586 ********************************************************************/
 587
 588 ssize_t del_share_mode(files_struct *fsp, share_mode_entry **ppse)
 589 {
 590         share_mode_entry entry;
 591
 592         /*
 593          * Fake up a share_mode_entry for comparisons.
 594          */
 595
 596         fill_share_mode((char *)&entry, fsp, 0, 0);
 597         return del_share_entry(fsp->dev, fsp->inode, &entry, ppse);
 598 }
 599
 600 /*******************************************************************
 601  Set the share mode of a file. Return False on fail, True on success.
 602 ********************************************************************/
 603
 604 BOOL set_share_mode(files_struct *fsp, uint16 port, uint16 op_type)
 605 {
 606         TDB_DATA dbuf;
 607         struct locking_data *data;
 608         char *p=NULL;
 609         int size;
 610         BOOL ret = True;
 611
 612         /* read in the existing share modes if any */
 613         dbuf = tdb_fetch(tdb, locking_key_fsp(fsp));
 614         if (!dbuf.dptr) {
 615                 /* we'll need to create a new record */
 616                 pstring fname;
 617
 618                 pstrcpy(fname, fsp->conn->connectpath);
 619                 pstrcat(fname, "/");
 620                 pstrcat(fname, fsp->fsp_name);
 621
 622                 size = sizeof(*data) + sizeof(share_mode_entry) + strlen(fname) + 1;
 623                 p = (char *)malloc(size);
 624                 if (!p)
 625                         return False;
 626                 data = (struct locking_data *)p;
 627                 data->u.num_share_mode_entries = 1;
 628
 629                 DEBUG(10,("set_share_mode: creating entry for file %s. num_share_modes = 1\n",
 630                         fsp->fsp_name ));
 631
 632                 pstrcpy(p + sizeof(*data) + sizeof(share_mode_entry), fname);
 633                 fill_share_mode(p + sizeof(*data), fsp, port, op_type);
 634                 dbuf.dptr = p;
 635                 dbuf.dsize = size;
 636                 if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1)
 637                         ret = False;
 638
 639                 print_share_mode_table((struct locking_data *)p);
 640
 641                 SAFE_FREE(p);
 642                 return ret;
 643         }
 644
 645         /* we're adding to an existing entry - this is a bit fiddly */
 646         data = (struct locking_data *)dbuf.dptr;
 647
 648         data->u.num_share_mode_entries++;
 649
 650         DEBUG(10,("set_share_mode: adding entry for file %s. new num_share_modes = %d\n",
 651                 fsp->fsp_name, data->u.num_share_mode_entries ));
 652
 653         size = dbuf.dsize + sizeof(share_mode_entry);
 654         p = malloc(size);
 655         if (!p)
 656                 return False;
 657         memcpy(p, dbuf.dptr, sizeof(*data));
 658         fill_share_mode(p + sizeof(*data), fsp, port, op_type);
 659         memcpy(p + sizeof(*data) + sizeof(share_mode_entry), dbuf.dptr + sizeof(*data),
 660                dbuf.dsize - sizeof(*data));
 661         SAFE_FREE(dbuf.dptr);
 662         dbuf.dptr = p;
 663         dbuf.dsize = size;
 664         if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1)
 665                 ret = False;
 666         print_share_mode_table((struct locking_data *)p);
 667         SAFE_FREE(p);
 668         return ret;
 669 }
 670
 671 /*******************************************************************
 672  A generic in-place modification call for share mode entries.
 673 ********************************************************************/
 674
 675 static BOOL mod_share_mode( SMB_DEV_T dev, SMB_INO_T inode, share_mode_entry *entry,
 676                            void (*mod_fn)(share_mode_entry *, SMB_DEV_T, SMB_INO_T, void *),
 677                            void *param)
 678 {
 679         TDB_DATA dbuf;
 680         struct locking_data *data;
 681         int i;
 682         share_mode_entry *shares;
 683         BOOL need_store=False;
 684         BOOL ret = True;
 685
 686         /* read in the existing share modes */
 687         dbuf = tdb_fetch(tdb, locking_key(dev, inode));
 688         if (!dbuf.dptr)
 689                 return False;
 690
 691         data = (struct locking_data *)dbuf.dptr;
 692         shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
 693
 694         /* find any with our pid and call the supplied function */
 695         for (i=0;i<data->u.num_share_mode_entries;i++) {
 696                 if (share_modes_identical(entry, &shares[i])) {
 697                         mod_fn(&shares[i], dev, inode, param);
 698                         need_store=True;
 699                 }
 700         }
 701
 702         /* if the mod fn was called then store it back */
 703         if (need_store) {
 704                 if (data->u.num_share_mode_entries == 0) {
 705                         if (tdb_delete(tdb, locking_key(dev, inode)) == -1)
 706                                 ret = False;
 707                 } else {
 708                         if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1)
 709                                 ret = False;
 710                 }
 711         }
 712
 713         SAFE_FREE(dbuf.dptr);
 714         return ret;
 715 }
 716
 717 /*******************************************************************
 718  Static function that actually does the work for the generic function
 719  below.
 720 ********************************************************************/
 721
 722 static void remove_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode,
 723                                    void *param)
 724 {
 725         DEBUG(10,("remove_share_oplock_fn: removing oplock info for entry dev=%x ino=%.0f\n",
 726                   (unsigned int)dev, (double)inode ));
 727         /* Delete the oplock info. */
 728         entry->op_port = 0;
 729         entry->op_type = NO_OPLOCK;
 730 }
 731
 732 /*******************************************************************
 733  Remove an oplock port and mode entry from a share mode.
 734 ********************************************************************/
 735
 736 BOOL remove_share_oplock(files_struct *fsp)
 737 {
 738         share_mode_entry entry;
 739         /*
 740          * Fake up an entry for comparisons...
 741          */
 742         fill_share_mode((char *)&entry, fsp, 0, 0);
 743         return mod_share_mode(fsp->dev, fsp->inode, &entry, remove_share_oplock_fn, NULL);
 744 }
 745
 746 /*******************************************************************
 747  Static function that actually does the work for the generic function
 748  below.
 749 ********************************************************************/
 750
 751 static void downgrade_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode,
 752                                    void *param)
 753 {
 754         DEBUG(10,("downgrade_share_oplock_fn: downgrading oplock info for entry dev=%x ino=%.0f\n",
 755                   (unsigned int)dev, (double)inode ));
 756         entry->op_type = LEVEL_II_OPLOCK;
 757 }
 758
 759 /*******************************************************************
 760  Downgrade a oplock type from exclusive to level II.
 761 ********************************************************************/
 762
 763 BOOL downgrade_share_oplock(files_struct *fsp)
 764 {
 765         share_mode_entry entry;
 766         /*
 767          * Fake up an entry for comparisons...
 768          */
 769         fill_share_mode((char *)&entry, fsp, 0, 0);
 770         return mod_share_mode(fsp->dev, fsp->inode, &entry, downgrade_share_oplock_fn, NULL);
 771 }
 772
 773 /*******************************************************************
 774  Get/Set the delete on close flag in a set of share modes.
 775  Return False on fail, True on success.
 776 ********************************************************************/
 777
 778 BOOL modify_delete_flag( SMB_DEV_T dev, SMB_INO_T inode, BOOL delete_on_close)
 779 {
 780         TDB_DATA dbuf;
 781         struct locking_data *data;
 782         int i;
 783         share_mode_entry *shares;
 784
 785         /* read in the existing share modes */
 786         dbuf = tdb_fetch(tdb, locking_key(dev, inode));
 787         if (!dbuf.dptr)
 788                 return False;
 789
 790         data = (struct locking_data *)dbuf.dptr;
 791         shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
 792
 793         /* Set/Unset the delete on close element. */
 794         for (i=0;i<data->u.num_share_mode_entries;i++,shares++) {
 795                 shares->share_mode = (delete_on_close ?
 796                             (shares->share_mode | DELETE_ON_CLOSE_FLAG) :
 797                             (shares->share_mode & ~DELETE_ON_CLOSE_FLAG) );
 798         }
 799
 800         /* store it back */
 801         if (data->u.num_share_mode_entries) {
 802                 if (tdb_store(tdb, locking_key(dev,inode), dbuf, TDB_REPLACE)==-1) {
 803                         SAFE_FREE(dbuf.dptr);
 804                         return False;
 805                 }
 806         }
 807
 808         SAFE_FREE(dbuf.dptr);
 809         return True;
 810 }
 811
 812 /****************************************************************************
 813  Traverse the whole database with this function, calling traverse_callback
 814  on each share mode
 815 ****************************************************************************/
 816
 817 static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf,
 818                        void* state)
 819 {
 820         struct locking_data *data;
 821         share_mode_entry *shares;
 822         char *name;
 823         int i;
 824
 825         SHAREMODE_FN(traverse_callback) = (SHAREMODE_FN_CAST())state;
 826
 827         data = (struct locking_data *)dbuf.dptr;
 828         shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
 829         name = dbuf.dptr + sizeof(*data) + data->u.num_share_mode_entries*sizeof(*shares);
 830
 831         for (i=0;i<data->u.num_share_mode_entries;i++) {
 832                 traverse_callback(&shares[i], name);
 833         }
 834         return 0;
 835 }
 836
 837 /*******************************************************************
 838  Call the specified function on each entry under management by the
 839  share mode system.
 840 ********************************************************************/
 841
 842 int share_mode_forall(SHAREMODE_FN(fn))
 843 {
 844         if (!tdb)
 845                 return 0;
 846         return tdb_traverse(tdb, traverse_fn, (void*)fn);
 847 }