r12203: Add the share path into the sharemode db. This involves
[samba.git] / source3 / 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    Copyright (C) Volker Lendecke 2005
7    
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12    
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17    
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21
22    Revision History:
23
24    12 aug 96: Erik.Devriendt@te6.siemens.be
25    added support for shared memory implementation of share mode locking
26
27    May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
28    locking to deal with multiple share modes per open file.
29
30    September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
31    support.
32
33    rewrtten completely to use new tdb code. Tridge, Dec '99
34
35    Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
36 */
37
38 #include "includes.h"
39 uint16 global_smbpid;
40
41 #undef DBGC_CLASS
42 #define DBGC_CLASS DBGC_LOCKING
43
44 /* the locking database handle */
45 static TDB_CONTEXT *tdb;
46
47 struct locking_data {
48         union {
49                 struct {
50                         int num_share_mode_entries;
51                         BOOL delete_on_close;
52                 } s;
53                 struct share_mode_entry dummy; /* Needed for alignment. */
54         } u;
55         /* the following two entries are implicit
56            struct share_mode_entry modes[num_share_mode_entries];
57            char file_name[];
58         */
59 };
60
61 /****************************************************************************
62  Debugging aid :-).
63 ****************************************************************************/
64
65 static const char *lock_type_name(enum brl_type lock_type)
66 {
67         return (lock_type == READ_LOCK) ? "READ" : "WRITE";
68 }
69
70 /****************************************************************************
71  Utility function called to see if a file region is locked.
72 ****************************************************************************/
73
74 BOOL is_locked(files_struct *fsp,connection_struct *conn,
75                SMB_BIG_UINT count,SMB_BIG_UINT offset, 
76                enum brl_type lock_type)
77 {
78         int snum = SNUM(conn);
79         int strict_locking = lp_strict_locking(snum);
80         BOOL ret;
81         
82         if (count == 0)
83                 return(False);
84
85         if (!lp_locking(snum) || !strict_locking)
86                 return(False);
87
88         if (strict_locking == Auto) {
89                 if  (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && (lock_type == READ_LOCK || lock_type == WRITE_LOCK)) {
90                         DEBUG(10,("is_locked: optimisation - exclusive oplock on file %s\n", fsp->fsp_name ));
91                         ret = 0;
92                 } else if ((fsp->oplock_type == LEVEL_II_OPLOCK) &&
93                            (lock_type == READ_LOCK)) {
94                         DEBUG(10,("is_locked: optimisation - level II oplock on file %s\n", fsp->fsp_name ));
95                         ret = 0;
96                 } else {
97                         ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
98                                      global_smbpid, procid_self(), conn->cnum, 
99                                      offset, count, lock_type);
100                 }
101         } else {
102                 ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
103                                 global_smbpid, procid_self(), conn->cnum,
104                                 offset, count, lock_type);
105         }
106
107         DEBUG(10,("is_locked: brl start=%.0f len=%.0f %s for file %s\n",
108                         (double)offset, (double)count, ret ? "locked" : "unlocked",
109                         fsp->fsp_name ));
110
111         /*
112          * There is no lock held by an SMB daemon, check to
113          * see if there is a POSIX lock from a UNIX or NFS process.
114          */
115
116         if(!ret && lp_posix_locking(snum)) {
117                 ret = is_posix_locked(fsp, offset, count, lock_type);
118
119                 DEBUG(10,("is_locked: posix start=%.0f len=%.0f %s for file %s\n",
120                                 (double)offset, (double)count, ret ? "locked" : "unlocked",
121                                 fsp->fsp_name ));
122         }
123
124         return ret;
125 }
126
127 /****************************************************************************
128  Utility function called by locking requests.
129 ****************************************************************************/
130
131 static NTSTATUS do_lock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
132                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type, BOOL *my_lock_ctx)
133 {
134         NTSTATUS status = NT_STATUS_LOCK_NOT_GRANTED;
135
136         if (!lp_locking(SNUM(conn)))
137                 return NT_STATUS_OK;
138
139         /* NOTE! 0 byte long ranges ARE allowed and should be stored  */
140
141         DEBUG(10,("do_lock: lock type %s start=%.0f len=%.0f requested for file %s\n",
142                   lock_type_name(lock_type), (double)offset, (double)count, fsp->fsp_name ));
143
144         if (OPEN_FSP(fsp) && fsp->can_lock && (fsp->conn == conn)) {
145                 status = brl_lock(fsp->dev, fsp->inode, fsp->fnum,
146                                   lock_pid, procid_self(), conn->cnum, 
147                                   offset, count, 
148                                   lock_type, my_lock_ctx);
149
150                 if (NT_STATUS_IS_OK(status) && lp_posix_locking(SNUM(conn))) {
151
152                         /*
153                          * Try and get a POSIX lock on this range.
154                          * Note that this is ok if it is a read lock
155                          * overlapping on a different fd. JRA.
156                          */
157
158                         if (!set_posix_lock(fsp, offset, count, lock_type)) {
159                                 if (errno == EACCES || errno == EAGAIN)
160                                         status = NT_STATUS_FILE_LOCK_CONFLICT;
161                                 else
162                                         status = map_nt_error_from_unix(errno);
163
164                                 /*
165                                  * We failed to map - we must now remove the brl
166                                  * lock entry.
167                                  */
168                                 (void)brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
169                                                                 lock_pid, procid_self(), conn->cnum, 
170                                                                 offset, count, False,
171                                                                 NULL, NULL);
172                         }
173                 }
174         }
175
176         return status;
177 }
178
179 /****************************************************************************
180  Utility function called by locking requests. This is *DISGUSTING*. It also
181  appears to be "What Windows Does" (tm). Andrew, ever wonder why Windows 2000
182  is so slow on the locking tests...... ? This is the reason. Much though I hate
183  it, we need this. JRA.
184 ****************************************************************************/
185
186 NTSTATUS do_lock_spin(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
187                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type, BOOL *my_lock_ctx)
188 {
189         int j, maxj = lp_lock_spin_count();
190         int sleeptime = lp_lock_sleep_time();
191         NTSTATUS status, ret;
192
193         if (maxj <= 0)
194                 maxj = 1;
195
196         ret = NT_STATUS_OK; /* to keep dumb compilers happy */
197
198         for (j = 0; j < maxj; j++) {
199                 status = do_lock(fsp, conn, lock_pid, count, offset, lock_type, my_lock_ctx);
200                 if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED) &&
201                     !NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
202                         return status;
203                 }
204                 /* if we do fail then return the first error code we got */
205                 if (j == 0) {
206                         ret = status;
207                         /* Don't spin if we blocked ourselves. */
208                         if (*my_lock_ctx)
209                                 return ret;
210                 }
211                 if (sleeptime)
212                         sys_usleep(sleeptime);
213         }
214         return ret;
215 }
216
217 /* Struct passed to brl_unlock. */
218 struct posix_unlock_data_struct {
219         files_struct *fsp;
220         SMB_BIG_UINT offset;
221         SMB_BIG_UINT count;
222 };
223
224 /****************************************************************************
225  Function passed to brl_unlock to allow POSIX unlock to be done first.
226 ****************************************************************************/
227
228 static void posix_unlock(void *pre_data)
229 {
230         struct posix_unlock_data_struct *pdata = (struct posix_unlock_data_struct *)pre_data;
231
232         if (lp_posix_locking(SNUM(pdata->fsp->conn)))
233                 release_posix_lock(pdata->fsp, pdata->offset, pdata->count);
234 }
235
236 /****************************************************************************
237  Utility function called by unlocking requests.
238 ****************************************************************************/
239
240 NTSTATUS do_unlock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
241                    SMB_BIG_UINT count,SMB_BIG_UINT offset)
242 {
243         BOOL ok = False;
244         struct posix_unlock_data_struct posix_data;
245         
246         if (!lp_locking(SNUM(conn)))
247                 return NT_STATUS_OK;
248         
249         if (!OPEN_FSP(fsp) || !fsp->can_lock || (fsp->conn != conn)) {
250                 return NT_STATUS_INVALID_HANDLE;
251         }
252         
253         DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for file %s\n",
254                   (double)offset, (double)count, fsp->fsp_name ));
255
256         /*
257          * Remove the existing lock record from the tdb lockdb
258          * before looking at POSIX locks. If this record doesn't
259          * match then don't bother looking to remove POSIX locks.
260          */
261
262         posix_data.fsp = fsp;
263         posix_data.offset = offset;
264         posix_data.count = count;
265
266         ok = brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
267                         lock_pid, procid_self(), conn->cnum, offset, count,
268                         False, posix_unlock, (void *)&posix_data);
269    
270         if (!ok) {
271                 DEBUG(10,("do_unlock: returning ERRlock.\n" ));
272                 return NT_STATUS_RANGE_NOT_LOCKED;
273         }
274         return NT_STATUS_OK;
275 }
276
277 /****************************************************************************
278  Remove any locks on this fd. Called from file_close().
279 ****************************************************************************/
280
281 void locking_close_file(files_struct *fsp)
282 {
283         struct process_id pid = procid_self();
284
285         if (!lp_locking(SNUM(fsp->conn)))
286                 return;
287
288         /*
289          * Just release all the brl locks, no need to release individually.
290          */
291
292         brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum);
293
294         if(lp_posix_locking(SNUM(fsp->conn))) {
295
296                 /* 
297                  * Release all the POSIX locks.
298                  */
299                 posix_locking_close_file(fsp);
300
301         }
302 }
303
304 /****************************************************************************
305  Initialise the locking functions.
306 ****************************************************************************/
307
308 static int open_read_only;
309
310 BOOL locking_init(int read_only)
311 {
312         brl_init(read_only);
313
314         if (tdb)
315                 return True;
316
317         tdb = tdb_open_log(lock_path("locking.tdb"), 
318                         SMB_OPEN_DATABASE_TDB_HASH_SIZE, TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST), 
319                         read_only?O_RDONLY:O_RDWR|O_CREAT,
320                         0644);
321
322         if (!tdb) {
323                 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
324                 return False;
325         }
326
327         if (!posix_locking_init(read_only))
328                 return False;
329
330         open_read_only = read_only;
331
332         return True;
333 }
334
335 /*******************************************************************
336  Deinitialize the share_mode management.
337 ******************************************************************/
338
339 BOOL locking_end(void)
340 {
341         BOOL ret = True;
342
343         brl_shutdown(open_read_only);
344         if (tdb) {
345                 if (tdb_close(tdb) != 0)
346                         ret = False;
347         }
348
349         return ret;
350 }
351
352 /*******************************************************************
353  Form a static locking key for a dev/inode pair.
354 ******************************************************************/
355
356 /* key and data records in the tdb locking database */
357 struct locking_key {
358         SMB_DEV_T dev;
359         SMB_INO_T ino;
360 };
361
362 /*******************************************************************
363  Form a static locking key for a dev/inode pair.
364 ******************************************************************/
365
366 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
367 {
368         static struct locking_key key;
369         TDB_DATA kbuf;
370
371         memset(&key, '\0', sizeof(key));
372         key.dev = dev;
373         key.ino = inode;
374         kbuf.dptr = (char *)&key;
375         kbuf.dsize = sizeof(key);
376         return kbuf;
377 }
378
379 /*******************************************************************
380  Print out a share mode.
381 ********************************************************************/
382
383 char *share_mode_str(int num, struct share_mode_entry *e)
384 {
385         static pstring share_str;
386
387         slprintf(share_str, sizeof(share_str)-1, "share_mode_entry[%d]: "
388                  "pid = %s, share_access = 0x%x, private_options = 0x%x, "
389                  "access_mask = 0x%x, mid = 0x%x, type= 0x%x, file_id = %lu, "
390                  "dev = 0x%x, inode = %.0f",
391                  num, procid_str_static(&e->pid),
392                  e->share_access, e->private_options,
393                  e->access_mask, e->op_mid, e->op_type, e->share_file_id,
394                  (unsigned int)e->dev, (double)e->inode );
395
396         return share_str;
397 }
398
399 /*******************************************************************
400  Print out a share mode table.
401 ********************************************************************/
402
403 static void print_share_mode_table(struct locking_data *data)
404 {
405         int num_share_modes = data->u.s.num_share_mode_entries;
406         struct share_mode_entry *shares =
407                 (struct share_mode_entry *)(data + 1);
408         int i;
409
410         for (i = 0; i < num_share_modes; i++) {
411                 struct share_mode_entry *entry_p = &shares[i];
412                 DEBUG(10,("print_share_mode_table: %s\n",
413                           share_mode_str(i, entry_p)));
414         }
415 }
416
417 /*******************************************************************
418  Get all share mode entries for a dev/inode pair.
419 ********************************************************************/
420
421 static BOOL parse_share_modes(TDB_DATA dbuf, struct share_mode_lock *lck)
422 {
423         struct locking_data *data;
424         int i;
425
426         if (dbuf.dsize < sizeof(struct locking_data)) {
427                 DEBUG(0, ("parse_share_modes: buffer too short\n"));
428                 return False;
429         }
430
431         data = (struct locking_data *)dbuf.dptr;
432
433         lck->delete_on_close = data->u.s.delete_on_close;
434         lck->num_share_modes = data->u.s.num_share_mode_entries;
435
436         DEBUG(10, ("parse_share_modes: delete_on_close: %d, "
437                    "num_share_modes: %d\n", lck->delete_on_close,
438                    lck->num_share_modes));
439
440         if ((lck->num_share_modes < 0) || (lck->num_share_modes > 1000000)) {
441                 DEBUG(0, ("invalid number of share modes: %d\n",
442                           lck->num_share_modes));
443                 return False;
444         }
445
446         lck->share_modes = NULL;
447
448         if (lck->num_share_modes != 0) {
449
450                 if (dbuf.dsize < (sizeof(struct locking_data) +
451                                   (lck->num_share_modes *
452                                    sizeof(struct share_mode_entry)))) {
453                         DEBUG(0, ("parse_share_modes: buffer too short\n"));
454                         return False;
455                 }
456                                   
457                 lck->share_modes = talloc_memdup(lck, dbuf.dptr+sizeof(*data),
458                                                  lck->num_share_modes *
459                                                  sizeof(struct share_mode_entry));
460
461                 if (lck->share_modes == NULL) {
462                         DEBUG(0, ("talloc failed\n"));
463                         return False;
464                 }
465         }
466
467         /* Save off the associated service path and filename. */
468         lck->servicepath = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
469                                       (lck->num_share_modes *
470                                       sizeof(struct share_mode_entry)));
471
472         lck->filename = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
473                                       (lck->num_share_modes *
474                                       sizeof(struct share_mode_entry)) +
475                                       strlen(lck->servicepath) + 1 );
476
477         /*
478          * Ensure that each entry has a real process attached.
479          */
480
481         for (i = 0; i < lck->num_share_modes; i++) {
482                 struct share_mode_entry *entry_p = &lck->share_modes[i];
483                 DEBUG(10,("parse_share_modes: %s\n",
484                           share_mode_str(i, entry_p) ));
485                 if (!process_exists(entry_p->pid)) {
486                         DEBUG(10,("parse_share_modes: deleted %s\n",
487                                   share_mode_str(i, entry_p) ));
488                         entry_p->op_type = UNUSED_SHARE_MODE_ENTRY;
489                         lck->modified = True;
490                 }
491         }
492
493         return True;
494 }
495
496 static TDB_DATA unparse_share_modes(struct share_mode_lock *lck)
497 {
498         TDB_DATA result;
499         int num_valid = 0;
500         int i;
501         struct locking_data *data;
502         ssize_t offset;
503         ssize_t sp_len;
504
505         result.dptr = NULL;
506         result.dsize = 0;
507
508         for (i=0; i<lck->num_share_modes; i++) {
509                 if (!is_unused_share_mode_entry(&lck->share_modes[i])) {
510                         num_valid += 1;
511                 }
512         }
513
514         if (num_valid == 0) {
515                 return result;
516         }
517
518         sp_len = strlen(lck->servicepath);
519
520         result.dsize = sizeof(*data) +
521                 lck->num_share_modes * sizeof(struct share_mode_entry) +
522                 sp_len + 1 +
523                 strlen(lck->filename) + 1;
524         result.dptr = talloc_size(lck, result.dsize);
525
526         if (result.dptr == NULL) {
527                 smb_panic("talloc failed\n");
528         }
529
530         data = (struct locking_data *)result.dptr;
531         ZERO_STRUCTP(data);
532         data->u.s.num_share_mode_entries = lck->num_share_modes;
533         data->u.s.delete_on_close = lck->delete_on_close;
534         DEBUG(10, ("unparse_share_modes: del: %d, num: %d\n",
535                    data->u.s.delete_on_close,
536                    data->u.s.num_share_mode_entries));
537         memcpy(result.dptr + sizeof(*data), lck->share_modes,
538                sizeof(struct share_mode_entry)*lck->num_share_modes);
539         offset = sizeof(*data) +
540                 sizeof(struct share_mode_entry)*lck->num_share_modes;
541         safe_strcpy(result.dptr + offset, lck->servicepath,
542                     result.dsize - offset - 1);
543         offset += sp_len + 1;
544         safe_strcpy(result.dptr + offset, lck->filename,
545                     result.dsize - offset - 1);
546         print_share_mode_table(data);
547         return result;
548 }
549
550 static int share_mode_lock_destructor(void *p)
551 {
552         struct share_mode_lock *lck =
553                 talloc_get_type_abort(p, struct share_mode_lock);
554         TDB_DATA key = locking_key(lck->dev, lck->ino);
555         TDB_DATA data;
556
557         if (!lck->modified) {
558                 goto done;
559         }
560
561         data = unparse_share_modes(lck);
562
563         if (data.dptr == NULL) {
564                 if (!lck->fresh) {
565                         /* There has been an entry before, delete it */
566                         if (tdb_delete(tdb, key) == -1) {
567                                 smb_panic("Could not delete share entry\n");
568                         }
569                 }
570                 goto done;
571         }
572
573         if (tdb_store(tdb, key, data, TDB_REPLACE) == -1) {
574                 smb_panic("Could not store share mode entry\n");
575         }
576
577  done:
578         tdb_chainunlock(tdb, key);
579
580         return 0;
581 }
582
583 struct share_mode_lock *get_share_mode_lock(TALLOC_CTX *mem_ctx,
584                                                 SMB_DEV_T dev, SMB_INO_T ino,
585                                                 const char *servicepath,
586                                                 const char *fname)
587 {
588         struct share_mode_lock *lck;
589         TDB_DATA key = locking_key(dev, ino);
590         TDB_DATA data;
591
592         lck = TALLOC_P(mem_ctx, struct share_mode_lock);
593         if (lck == NULL) {
594                 DEBUG(0, ("talloc failed\n"));
595                 return NULL;
596         }
597
598         lck->dev = dev;
599         lck->ino = ino;
600         lck->delete_on_close = False;
601         lck->num_share_modes = 0;
602         lck->share_modes = NULL;
603         lck->modified = False;
604
605         if (tdb_chainlock(tdb, key) != 0) {
606                 DEBUG(3, ("Could not lock share entry\n"));
607                 talloc_free(lck);
608                 return NULL;
609         }
610
611         data = tdb_fetch(tdb, key);
612         lck->fresh = (data.dptr == NULL);
613
614         if (lck->fresh) {
615
616                 if (fname == NULL || servicepath == NULL) {
617                         DEBUG(0, ("New file, but no filename or servicepath supplied\n"));
618                         talloc_free(lck);
619                         return NULL;
620                 }
621                 lck->filename = talloc_strdup(lck, fname);
622                 lck->servicepath = talloc_strdup(lck, servicepath);
623                 if (lck->filename == NULL || lck->servicepath == NULL) {
624                         DEBUG(0, ("talloc failed\n"));
625                         talloc_free(lck);
626                         return NULL;
627                 }
628         } else {
629                 if (!parse_share_modes(data, lck)) {
630                         DEBUG(0, ("Could not parse share modes\n"));
631                         talloc_free(lck);
632                         SAFE_FREE(data.dptr);
633                         return NULL;
634                 }
635         }
636
637         talloc_set_destructor(lck, share_mode_lock_destructor);
638         SAFE_FREE(data.dptr);
639
640         return lck;
641 }
642
643 /*******************************************************************
644  Sets the service name and filename for rename.
645  At this point we should emit "rename" smbd messages to all
646  interested process id's.
647 ********************************************************************/
648
649 BOOL rename_share_filename(struct share_mode_lock *lck,
650                         const char *servicepath,
651                         const char *newname)
652 {
653         /*
654          * rename_internal_fsp() and rename_internals() add './' to
655          * head of newname if newname does not contain a '/'.
656          */
657         while (newname[0] && newname[1] && newname[0] == '.' && newname[1] == '/') {
658                 newname += 2;
659         }
660
661         lck->filename = talloc_strdup(lck, newname);
662         lck->servicepath = talloc_strdup(lck, servicepath);
663         if (lck->filename == NULL || lck->servicepath == NULL) {
664                 DEBUG(0, ("rename_share_filename: talloc failed\n"));
665                 return False;
666         }
667         lck->modified = True;
668         return True;
669 }
670
671 BOOL get_delete_on_close_flag(SMB_DEV_T dev, SMB_INO_T inode)
672 {
673         BOOL result;
674         struct share_mode_lock *lck = get_share_mode_lock(NULL, dev, inode, NULL, NULL);
675         if (!lck) {
676                 return False;
677         }
678         result = lck->delete_on_close;
679         talloc_free(lck);
680         return result;
681 }
682
683 BOOL is_valid_share_mode_entry(const struct share_mode_entry *e)
684 {
685         int num_props = 0;
686
687         num_props += ((e->op_type == NO_OPLOCK) ? 1 : 0);
688         num_props += (EXCLUSIVE_OPLOCK_TYPE(e->op_type) ? 1 : 0);
689         num_props += (LEVEL_II_OPLOCK_TYPE(e->op_type) ? 1 : 0);
690
691         SMB_ASSERT(num_props <= 1);
692         return (num_props != 0);
693 }
694
695 BOOL is_deferred_open_entry(const struct share_mode_entry *e)
696 {
697         return (e->op_type == DEFERRED_OPEN_ENTRY);
698 }
699
700 BOOL is_unused_share_mode_entry(const struct share_mode_entry *e)
701 {
702         return (e->op_type == UNUSED_SHARE_MODE_ENTRY);
703 }
704
705 /*******************************************************************
706  Fill a share mode entry.
707 ********************************************************************/
708
709 static void fill_share_mode_entry(struct share_mode_entry *e,
710                                   files_struct *fsp,
711                                   uint16 mid, uint16 op_type)
712 {
713         ZERO_STRUCTP(e);
714         e->pid = procid_self();
715         e->share_access = fsp->share_access;
716         e->private_options = fsp->fh->private_options;
717         e->access_mask = fsp->access_mask;
718         e->op_mid = mid;
719         e->op_type = op_type;
720         e->time.tv_sec = fsp->open_time.tv_sec;
721         e->time.tv_usec = fsp->open_time.tv_usec;
722         e->share_file_id = fsp->file_id;
723         e->dev = fsp->dev;
724         e->inode = fsp->inode;
725 }
726
727 static void fill_deferred_open_entry(struct share_mode_entry *e,
728                                      const struct timeval request_time,
729                                      SMB_DEV_T dev, SMB_INO_T ino, uint16 mid)
730 {
731         ZERO_STRUCTP(e);
732         e->pid = procid_self();
733         e->op_mid = mid;
734         e->op_type = DEFERRED_OPEN_ENTRY;
735         e->time.tv_sec = request_time.tv_sec;
736         e->time.tv_usec = request_time.tv_usec;
737         e->dev = dev;
738         e->inode = ino;
739 }
740
741 static void add_share_mode_entry(struct share_mode_lock *lck,
742                                  const struct share_mode_entry *entry)
743 {
744         int i;
745
746         for (i=0; i<lck->num_share_modes; i++) {
747                 struct share_mode_entry *e = &lck->share_modes[i];
748                 if (is_unused_share_mode_entry(e)) {
749                         *e = *entry;
750                         break;
751                 }
752         }
753
754         if (i == lck->num_share_modes) {
755                 /* No unused entry found */
756                 ADD_TO_ARRAY(lck, struct share_mode_entry, *entry,
757                              &lck->share_modes, &lck->num_share_modes);
758         }
759         lck->modified = True;
760 }
761
762 void set_share_mode(struct share_mode_lock *lck, files_struct *fsp,
763                     uint16 mid, uint16 op_type)
764 {
765         struct share_mode_entry entry;
766         fill_share_mode_entry(&entry, fsp, mid, op_type);
767         add_share_mode_entry(lck, &entry);
768 }
769
770 void add_deferred_open(struct share_mode_lock *lck, uint16 mid,
771                        struct timeval request_time,
772                        SMB_DEV_T dev, SMB_INO_T ino)
773 {
774         struct share_mode_entry entry;
775         fill_deferred_open_entry(&entry, request_time, dev, ino, mid);
776         add_share_mode_entry(lck, &entry);
777 }
778
779 /*******************************************************************
780  Check if two share mode entries are identical, ignoring oplock 
781  and mid info and desired_access.
782 ********************************************************************/
783
784 static BOOL share_modes_identical(struct share_mode_entry *e1,
785                                   struct share_mode_entry *e2)
786 {
787 #if 1 /* JRA PARANOIA TEST - REMOVE LATER */
788         if (procid_equal(&e1->pid, &e2->pid) &&
789             e1->share_file_id == e2->share_file_id &&
790             e1->dev == e2->dev &&
791             e1->inode == e2->inode &&
792             (e1->share_access) != (e2->share_access)) {
793                 DEBUG(0,("PANIC: share_modes_identical: share_mode "
794                          "mismatch (e1 = 0x%x, e2 = 0x%x). Logic error.\n",
795                          (unsigned int)e1->share_access,
796                          (unsigned int)e2->share_access ));
797                 smb_panic("PANIC: share_modes_identical logic error.\n");
798         }
799 #endif
800
801         return (procid_equal(&e1->pid, &e2->pid) &&
802                 (e1->share_access) == (e2->share_access) &&
803                 e1->dev == e2->dev &&
804                 e1->inode == e2->inode &&
805                 e1->share_file_id == e2->share_file_id );
806 }
807
808 static BOOL deferred_open_identical(struct share_mode_entry *e1,
809                                     struct share_mode_entry *e2)
810 {
811         return (procid_equal(&e1->pid, &e2->pid) &&
812                 (e1->op_mid == e2->op_mid) &&
813                 (e1->dev == e2->dev) &&
814                 (e1->inode == e2->inode));
815 }
816
817 static struct share_mode_entry *find_share_mode_entry(struct share_mode_lock *lck,
818                                                       struct share_mode_entry *entry)
819 {
820         int i;
821
822         for (i=0; i<lck->num_share_modes; i++) {
823                 struct share_mode_entry *e = &lck->share_modes[i];
824                 if (is_valid_share_mode_entry(entry) &&
825                     is_valid_share_mode_entry(e) &&
826                     share_modes_identical(e, entry)) {
827                         return e;
828                 }
829                 if (is_deferred_open_entry(entry) &&
830                     is_deferred_open_entry(e) &&
831                     deferred_open_identical(e, entry)) {
832                         return e;
833                 }
834         }
835         return NULL;
836 }
837
838 /*******************************************************************
839  Del the share mode of a file for this process. Return the number of
840  entries left.
841 ********************************************************************/
842
843 BOOL del_share_mode(struct share_mode_lock *lck, files_struct *fsp)
844 {
845         struct share_mode_entry entry, *e;
846
847         fill_share_mode_entry(&entry, fsp, 0, 0);
848
849         e = find_share_mode_entry(lck, &entry);
850         if (e == NULL) {
851                 return False;
852         }
853
854         e->op_type = UNUSED_SHARE_MODE_ENTRY;
855         lck->modified = True;
856         return True;
857 }
858
859 void del_deferred_open_entry(struct share_mode_lock *lck, uint16 mid)
860 {
861         struct share_mode_entry entry, *e;
862
863         fill_deferred_open_entry(&entry, timeval_zero(),
864                                  lck->dev, lck->ino, mid);
865
866         e = find_share_mode_entry(lck, &entry);
867         if (e == NULL) {
868                 return;
869         }
870
871         e->op_type = UNUSED_SHARE_MODE_ENTRY;
872         lck->modified = True;
873 }
874
875 /*******************************************************************
876  Remove an oplock mid and mode entry from a share mode.
877 ********************************************************************/
878
879 BOOL remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
880 {
881         struct share_mode_entry entry, *e;
882
883         fill_share_mode_entry(&entry, fsp, 0, 0);
884
885         e = find_share_mode_entry(lck, &entry);
886         if (e == NULL) {
887                 return False;
888         }
889
890         e->op_mid = 0;
891         e->op_type = NO_OPLOCK;
892         lck->modified = True;
893         return True;
894 }
895
896 /*******************************************************************
897  Downgrade a oplock type from exclusive to level II.
898 ********************************************************************/
899
900 BOOL downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
901 {
902         struct share_mode_entry entry, *e;
903
904         fill_share_mode_entry(&entry, fsp, 0, 0);
905
906         e = find_share_mode_entry(lck, &entry);
907         if (e == NULL) {
908                 return False;
909         }
910
911         e->op_type = LEVEL_II_OPLOCK;
912         lck->modified = True;
913         return True;
914 }
915
916
917 /*******************************************************************
918  We've just told all the smbd's that our level2 or fake level2 has been
919  written to.
920 ********************************************************************/
921 BOOL remove_all_share_oplocks(struct share_mode_lock *lck, files_struct *fsp)
922 {
923         int i;
924         for (i=0; i<lck->num_share_modes; i++) {
925                 struct share_mode_entry *e = &lck->share_modes[i];
926                 if (!is_valid_share_mode_entry(e)) {
927                         continue;
928                 }
929                 if (e->op_type == NO_OPLOCK) {
930                         continue;
931                 }
932                 e->op_type = NO_OPLOCK;
933                 lck->modified = True;
934         }
935         return True;
936 }
937
938 /****************************************************************************
939  Deal with the internal needs of setting the delete on close flag. Note that
940  as the tdb locking is recursive, it is safe to call this from within 
941  open_file_shared. JRA.
942 ****************************************************************************/
943
944 NTSTATUS can_set_delete_on_close(files_struct *fsp, BOOL delete_on_close,
945                                  uint32 dosmode)
946 {
947         if (!delete_on_close) {
948                 return NT_STATUS_OK;
949         }
950
951         /*
952          * Only allow delete on close for writable files.
953          */
954
955         if ((dosmode & aRONLY) &&
956             !lp_delete_readonly(SNUM(fsp->conn))) {
957                 DEBUG(10,("can_set_delete_on_close: file %s delete on close "
958                           "flag set but file attribute is readonly.\n",
959                           fsp->fsp_name ));
960                 return NT_STATUS_CANNOT_DELETE;
961         }
962
963         /*
964          * Only allow delete on close for writable shares.
965          */
966
967         if (!CAN_WRITE(fsp->conn)) {
968                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
969                           "close flag set but write access denied on share.\n",
970                           fsp->fsp_name ));
971                 return NT_STATUS_ACCESS_DENIED;
972         }
973
974         /*
975          * Only allow delete on close for files/directories opened with delete
976          * intent.
977          */
978
979         if (!(fsp->access_mask & DELETE_ACCESS)) {
980                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
981                           "close flag set but delete access denied.\n",
982                           fsp->fsp_name ));
983                 return NT_STATUS_ACCESS_DENIED;
984         }
985
986         return NT_STATUS_OK;
987 }
988
989 /****************************************************************************
990  Sets the delete on close flag over all share modes on this file.
991  Modify the share mode entry for all files open
992  on this device and inode to tell other smbds we have
993  changed the delete on close flag. This will be noticed
994  in the close code, the last closer will delete the file
995  if flag is set.
996 ****************************************************************************/
997
998 BOOL set_delete_on_close(files_struct *fsp, BOOL delete_on_close)
999 {
1000         struct share_mode_lock *lck;
1001         
1002         DEBUG(10,("set_delete_on_close: %s delete on close flag for "
1003                   "fnum = %d, file %s\n",
1004                   delete_on_close ? "Adding" : "Removing", fsp->fnum,
1005                   fsp->fsp_name ));
1006
1007         if (fsp->is_stat) {
1008                 return True;
1009         }
1010
1011         lck = get_share_mode_lock(NULL, fsp->dev, fsp->inode, NULL, NULL);
1012         if (lck == NULL) {
1013                 return False;
1014         }
1015         if (lck->delete_on_close != delete_on_close) {
1016                 lck->delete_on_close = delete_on_close;
1017                 lck->modified = True;
1018         }
1019
1020         talloc_free(lck);
1021         return True;
1022 }
1023
1024 static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, 
1025                        void *state)
1026 {
1027         struct locking_data *data;
1028         struct share_mode_entry *shares;
1029         const char *sharepath;
1030         const char *fname;
1031         int i;
1032         void (*traverse_callback)(struct share_mode_entry *, const char *, const char *) = state;
1033
1034         /* Ensure this is a locking_key record. */
1035         if (kbuf.dsize != sizeof(struct locking_key))
1036                 return 0;
1037
1038         data = (struct locking_data *)dbuf.dptr;
1039         shares = (struct share_mode_entry *)(dbuf.dptr + sizeof(*data));
1040         sharepath = dbuf.dptr + sizeof(*data) +
1041                 data->u.s.num_share_mode_entries*sizeof(*shares);
1042         fname = dbuf.dptr + sizeof(*data) +
1043                 data->u.s.num_share_mode_entries*sizeof(*shares) +
1044                 strlen(sharepath) + 1;
1045
1046         for (i=0;i<data->u.s.num_share_mode_entries;i++) {
1047                 traverse_callback(&shares[i], sharepath, fname);
1048         }
1049         return 0;
1050 }
1051
1052 /*******************************************************************
1053  Call the specified function on each entry under management by the
1054  share mode system.
1055 ********************************************************************/
1056
1057 int share_mode_forall(void (*fn)(const struct share_mode_entry *, const char *, const char *))
1058 {
1059         if (tdb == NULL)
1060                 return 0;
1061         return tdb_traverse(tdb, traverse_fn, fn);
1062 }