2 Unix SMB/Netbios implementation.
5 Copyright (C) Andrew Tridgell 1992-2000
6 Copyright (C) Jeremy Allison 1992-2000
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.
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.
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.
24 12 aug 96: Erik.Devriendt@te6.siemens.be
25 added support for shared memory implementation of share mode locking
27 May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
28 locking to deal with multiple share modes per open file.
30 September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
33 rewrtten completely to use new tdb code. Tridge, Dec '99
35 Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
39 extern int DEBUGLEVEL;
42 /* the locking database handle */
43 static TDB_CONTEXT *tdb;
45 /****************************************************************************
47 ****************************************************************************/
49 static const char *lock_type_name(enum brl_type lock_type)
51 return (lock_type == READ_LOCK) ? "READ" : "WRITE";
54 /****************************************************************************
55 Utility function called to see if a file region is locked.
56 If check_self is True, then checks on our own fd with the same locking context
57 are still made. If check_self is False, then checks are not made on our own fd
58 with the same locking context are not made.
59 ****************************************************************************/
61 BOOL is_locked(files_struct *fsp,connection_struct *conn,
62 SMB_BIG_UINT count,SMB_BIG_UINT offset,
63 enum brl_type lock_type, BOOL check_self)
65 int snum = SNUM(conn);
71 if (!lp_locking(snum) || !lp_strict_locking(snum))
74 ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
75 global_smbpid, sys_getpid(), conn->cnum,
76 offset, count, lock_type, check_self);
78 DEBUG(10,("is_locked: brl start=%.0f len=%.0f %s for file %s\n",
79 (double)offset, (double)count, ret ? "locked" : "unlocked",
83 * There is no lock held by an SMB daemon, check to
84 * see if there is a POSIX lock from a UNIX or NFS process.
87 if(!ret && lp_posix_locking(snum)) {
88 ret = is_posix_locked(fsp, offset, count, lock_type);
90 DEBUG(10,("is_locked: posix start=%.0f len=%.0f %s for file %s\n",
91 (double)offset, (double)count, ret ? "locked" : "unlocked",
98 /****************************************************************************
99 Utility function called by locking requests.
100 ****************************************************************************/
102 NTSTATUS do_lock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
103 SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type)
107 if (!lp_locking(SNUM(conn)))
110 /* NOTE! 0 byte long ranges ARE allowed and should be stored */
113 DEBUG(10,("do_lock: lock type %s start=%.0f len=%.0f requested for file %s\n",
114 lock_type_name(lock_type), (double)offset, (double)count, fsp->fsp_name ));
116 if (OPEN_FSP(fsp) && fsp->can_lock && (fsp->conn == conn)) {
117 ok = brl_lock(fsp->dev, fsp->inode, fsp->fnum,
118 lock_pid, sys_getpid(), conn->cnum,
122 if (ok && lp_posix_locking(SNUM(conn))) {
125 * Try and get a POSIX lock on this range.
126 * Note that this is ok if it is a read lock
127 * overlapping on a different fd. JRA.
130 ok = set_posix_lock(fsp, offset, count, lock_type);
134 * We failed to map - we must now remove the brl
137 (void)brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
138 lock_pid, sys_getpid(), conn->cnum,
144 if (!ok) return NT_STATUS_FILE_LOCK_CONFLICT;
146 return NT_STATUS_OK; /* Got lock */
149 /****************************************************************************
150 Utility function called by unlocking requests.
151 ****************************************************************************/
153 NTSTATUS do_unlock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
154 SMB_BIG_UINT count,SMB_BIG_UINT offset)
158 if (!lp_locking(SNUM(conn)))
161 if (!OPEN_FSP(fsp) || !fsp->can_lock || (fsp->conn != conn)) {
162 return NT_STATUS_INVALID_HANDLE;
165 DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for file %s\n",
166 (double)offset, (double)count, fsp->fsp_name ));
169 * Remove the existing lock record from the tdb lockdb
170 * before looking at POSIX locks. If this record doesn't
171 * match then don't bother looking to remove POSIX locks.
174 ok = brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
175 lock_pid, sys_getpid(), conn->cnum, offset, count);
178 DEBUG(10,("do_unlock: returning ERRlock.\n" ));
179 return NT_STATUS_LOCK_NOT_GRANTED;
182 if (!lp_posix_locking(SNUM(conn)))
185 (void)release_posix_lock(fsp, offset, count);
190 /****************************************************************************
191 Remove any locks on this fd. Called from file_close().
192 ****************************************************************************/
194 void locking_close_file(files_struct *fsp)
196 pid_t pid = sys_getpid();
198 if (!lp_locking(SNUM(fsp->conn)))
202 * Just release all the brl locks, no need to release individually.
205 brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum);
207 if(lp_posix_locking(SNUM(fsp->conn))) {
210 * Release all the POSIX locks.
212 posix_locking_close_file(fsp);
217 /****************************************************************************
218 Delete a record if it is for a dead process, if check_self is true, then
219 delete any records belonging to this pid also (there shouldn't be any).
220 This function is only called on locking startup and shutdown.
221 ****************************************************************************/
223 static int delete_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
225 struct locking_data *data;
226 share_mode_entry *shares;
228 pid_t mypid = sys_getpid();
229 BOOL check_self = *(BOOL *)state;
232 tdb_chainlock(tdb, kbuf);
234 data = (struct locking_data *)dbuf.dptr;
235 shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
237 for (i=0;i<data->num_share_mode_entries;) {
239 if (check_self && (shares[i].pid == mypid)) {
240 DEBUG(0,("locking : delete_fn. LOGIC ERROR ! Shutting down and a record for my pid (%u) exists !\n",
241 (unsigned int)shares[i].pid ));
242 } else if (!process_exists(shares[i].pid)) {
243 DEBUG(0,("locking : delete_fn. LOGIC ERROR ! Entry for pid %u and it no longer exists !\n",
244 (unsigned int)shares[i].pid ));
246 /* Process exists, leave this record alone. */
251 data->num_share_mode_entries--;
252 memmove(&shares[i], &shares[i+1],
253 dbuf.dsize - (sizeof(*data) + (i+1)*sizeof(*shares)));
258 /* the record has shrunk a bit */
259 dbuf.dsize -= del_count * sizeof(*shares);
261 /* store it back in the database */
262 if (data->num_share_mode_entries == 0) {
263 if (tdb_delete(ttdb, kbuf) == -1)
266 if (tdb_store(ttdb, kbuf, dbuf, TDB_REPLACE) == -1)
270 tdb_chainunlock(tdb, kbuf);
274 /****************************************************************************
275 Initialise the locking functions.
276 ****************************************************************************/
278 static int open_read_only;
280 BOOL locking_init(int read_only)
282 BOOL check_self = False;
289 tdb = tdb_open_log(lock_path("locking.tdb"),
290 0, USE_TDB_MMAP_FLAG|(read_only?0x0:TDB_CLEAR_IF_FIRST),
291 read_only?O_RDONLY:O_RDWR|O_CREAT,
295 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
299 if (!posix_locking_init(read_only))
302 /* delete any dead locks */
304 tdb_traverse(tdb, delete_fn, &check_self);
306 open_read_only = read_only;
311 /*******************************************************************
312 Deinitialize the share_mode management.
313 ******************************************************************/
315 BOOL locking_end(void)
317 BOOL check_self = True;
319 brl_shutdown(open_read_only);
322 /* delete any dead locks */
325 tdb_traverse(tdb, delete_fn, &check_self);
327 if (tdb_close(tdb) != 0)
334 /*******************************************************************
335 Form a static locking key for a dev/inode pair.
336 ******************************************************************/
338 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
340 static struct locking_key key;
343 memset(&key, '\0', sizeof(key));
346 kbuf.dptr = (char *)&key;
347 kbuf.dsize = sizeof(key);
351 static TDB_DATA locking_key_fsp(files_struct *fsp)
353 return locking_key(fsp->dev, fsp->inode);
356 #ifndef LOCK_SHARE_ENTRY_SPIN_COUNT
357 #define LOCK_SHARE_ENTRY_SPIN_COUNT 100
360 /*******************************************************************
361 Lock a hash bucket entry.
362 ******************************************************************/
364 BOOL lock_share_entry(connection_struct *conn,
365 SMB_DEV_T dev, SMB_INO_T inode)
369 for (count = 0; count < LOCK_SHARE_ENTRY_SPIN_COUNT; count++)
370 if (tdb_chainlock(tdb, locking_key(dev, inode)) == 0)
373 DEBUG(0,("lock_share_entry: locking (%d) for dev = %x, inode = %.0f failed with error %s\n",
374 count, (unsigned int)dev, (double)inode, strerror(errno) ));
377 return tdb_chainlock(tdb, locking_key(dev, inode)) == 0;
381 /*******************************************************************
382 Unlock a hash bucket entry.
383 ******************************************************************/
385 void unlock_share_entry(connection_struct *conn,
386 SMB_DEV_T dev, SMB_INO_T inode)
388 tdb_chainunlock(tdb, locking_key(dev, inode));
391 /*******************************************************************
392 Lock a hash bucket entry. use a fsp for convenience
393 ******************************************************************/
395 BOOL lock_share_entry_fsp(files_struct *fsp)
399 for (count = 0; count < LOCK_SHARE_ENTRY_SPIN_COUNT; count++)
400 if (tdb_chainlock(tdb, locking_key(fsp->dev, fsp->inode)) == 0)
403 DEBUG(0,("lock_share_entry_fsp: locking (%d) for dev = %x, inode = %.0f failed with error %s\n",
404 count, (unsigned int)fsp->dev, (double)fsp->inode, strerror(errno) ));
407 return tdb_chainlock(tdb, locking_key(fsp->dev, fsp->inode)) == 0;
411 /*******************************************************************
412 Unlock a hash bucket entry.
413 ******************************************************************/
415 void unlock_share_entry_fsp(files_struct *fsp)
417 tdb_chainunlock(tdb, locking_key(fsp->dev, fsp->inode));
420 /*******************************************************************
421 Get all share mode entries for a dev/inode pair.
422 ********************************************************************/
424 int get_share_modes(connection_struct *conn,
425 SMB_DEV_T dev, SMB_INO_T inode,
426 share_mode_entry **shares)
429 struct locking_data *data;
434 dbuf = tdb_fetch(tdb, locking_key(dev, inode));
438 data = (struct locking_data *)dbuf.dptr;
439 ret = data->num_share_mode_entries;
441 *shares = (share_mode_entry *)memdup(dbuf.dptr + sizeof(*data), ret * sizeof(**shares));
450 /*******************************************************************
451 Fill a share mode entry.
452 ********************************************************************/
454 static void fill_share_mode(char *p, files_struct *fsp, uint16 port, uint16 op_type)
456 share_mode_entry *e = (share_mode_entry *)p;
457 memset(e, '\0', sizeof(share_mode_entry));
458 e->pid = sys_getpid();
459 e->share_mode = fsp->share_mode;
461 e->op_type = op_type;
462 memcpy((char *)&e->time, (char *)&fsp->open_time, sizeof(struct timeval));
465 /*******************************************************************
466 Check if two share mode entries are identical, ignoring oplock
468 ********************************************************************/
470 BOOL share_modes_identical( share_mode_entry *e1, share_mode_entry *e2)
472 return (e1->pid == e2->pid &&
473 e1->share_mode == e2->share_mode &&
474 e1->time.tv_sec == e2->time.tv_sec &&
475 e1->time.tv_usec == e2->time.tv_usec );
478 /*******************************************************************
479 Delete a specific share mode. Return the number
480 of entries left, and a memdup'ed copy of the entry deleted (if required).
481 Ignore if no entry deleted.
482 ********************************************************************/
484 ssize_t del_share_entry( SMB_DEV_T dev, SMB_INO_T inode,
485 share_mode_entry *entry, share_mode_entry **ppse)
488 struct locking_data *data;
490 share_mode_entry *shares;
496 /* read in the existing share modes */
497 dbuf = tdb_fetch(tdb, locking_key(dev, inode));
501 data = (struct locking_data *)dbuf.dptr;
502 shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
505 * Find any with this pid and delete it
506 * by overwriting with the rest of the data
510 DEBUG(10,("del_share_mode: num_share_modes = %d\n", data->num_share_mode_entries ));
512 for (i=0;i<data->num_share_mode_entries;) {
513 if (share_modes_identical(&shares[i], entry)) {
515 *ppse = memdup(&shares[i], sizeof(*shares));
516 data->num_share_mode_entries--;
517 memmove(&shares[i], &shares[i+1],
518 dbuf.dsize - (sizeof(*data) + (i+1)*sizeof(*shares)));
521 DEBUG(10,("del_share_mode: deleting entry %d\n", i ));
529 /* the record may have shrunk a bit */
530 dbuf.dsize -= del_count * sizeof(*shares);
532 count = (ssize_t)data->num_share_mode_entries;
534 /* store it back in the database */
535 if (data->num_share_mode_entries == 0) {
536 if (tdb_delete(tdb, locking_key(dev, inode)) == -1)
539 if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1)
547 /*******************************************************************
548 Del the share mode of a file for this process. Return the number
549 of entries left, and a memdup'ed copy of the entry deleted.
550 ********************************************************************/
552 ssize_t del_share_mode(files_struct *fsp, share_mode_entry **ppse)
554 share_mode_entry entry;
557 * Fake up a share_mode_entry for comparisons.
560 fill_share_mode((char *)&entry, fsp, 0, 0);
561 return del_share_entry(fsp->dev, fsp->inode, &entry, ppse);
564 /*******************************************************************
565 Set the share mode of a file. Return False on fail, True on success.
566 ********************************************************************/
568 BOOL set_share_mode(files_struct *fsp, uint16 port, uint16 op_type)
571 struct locking_data *data;
576 /* read in the existing share modes if any */
577 dbuf = tdb_fetch(tdb, locking_key_fsp(fsp));
579 /* we'll need to create a new record */
582 pstrcpy(fname, fsp->conn->connectpath);
584 pstrcat(fname, fsp->fsp_name);
586 size = sizeof(*data) + sizeof(share_mode_entry) + strlen(fname) + 1;
587 p = (char *)malloc(size);
590 data = (struct locking_data *)p;
591 data->num_share_mode_entries = 1;
592 pstrcpy(p + sizeof(*data) + sizeof(share_mode_entry), fname);
593 fill_share_mode(p + sizeof(*data), fsp, port, op_type);
596 if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1)
602 /* we're adding to an existing entry - this is a bit fiddly */
603 data = (struct locking_data *)dbuf.dptr;
605 data->num_share_mode_entries++;
606 size = dbuf.dsize + sizeof(share_mode_entry);
610 memcpy(p, dbuf.dptr, sizeof(*data));
611 fill_share_mode(p + sizeof(*data), fsp, port, op_type);
612 memcpy(p + sizeof(*data) + sizeof(share_mode_entry), dbuf.dptr + sizeof(*data),
613 dbuf.dsize - sizeof(*data));
617 if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1)
623 /*******************************************************************
624 A generic in-place modification call for share mode entries.
625 ********************************************************************/
627 static BOOL mod_share_mode( SMB_DEV_T dev, SMB_INO_T inode, share_mode_entry *entry,
628 void (*mod_fn)(share_mode_entry *, SMB_DEV_T, SMB_INO_T, void *),
632 struct locking_data *data;
634 share_mode_entry *shares;
635 BOOL need_store=False;
637 /* read in the existing share modes */
638 dbuf = tdb_fetch(tdb, locking_key(dev, inode));
642 data = (struct locking_data *)dbuf.dptr;
643 shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
645 /* find any with our pid and call the supplied function */
646 for (i=0;i<data->num_share_mode_entries;i++) {
647 if (share_modes_identical(entry, &shares[i])) {
648 mod_fn(&shares[i], dev, inode, param);
653 /* if the mod fn was called then store it back */
655 if (data->num_share_mode_entries == 0) {
656 if (tdb_delete(tdb, locking_key(dev, inode)) == -1)
659 if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1)
668 /*******************************************************************
669 Static function that actually does the work for the generic function
671 ********************************************************************/
673 static void remove_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode,
676 DEBUG(10,("remove_share_oplock_fn: removing oplock info for entry dev=%x ino=%.0f\n",
677 (unsigned int)dev, (double)inode ));
678 /* Delete the oplock info. */
680 entry->op_type = NO_OPLOCK;
683 /*******************************************************************
684 Remove an oplock port and mode entry from a share mode.
685 ********************************************************************/
687 BOOL remove_share_oplock(files_struct *fsp)
689 share_mode_entry entry;
691 * Fake up an entry for comparisons...
693 fill_share_mode((char *)&entry, fsp, 0, 0);
694 return mod_share_mode(fsp->dev, fsp->inode, &entry, remove_share_oplock_fn, NULL);
697 /*******************************************************************
698 Static function that actually does the work for the generic function
700 ********************************************************************/
702 static void downgrade_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode,
705 DEBUG(10,("downgrade_share_oplock_fn: downgrading oplock info for entry dev=%x ino=%.0f\n",
706 (unsigned int)dev, (double)inode ));
707 entry->op_type = LEVEL_II_OPLOCK;
710 /*******************************************************************
711 Downgrade a oplock type from exclusive to level II.
712 ********************************************************************/
714 BOOL downgrade_share_oplock(files_struct *fsp)
716 share_mode_entry entry;
718 * Fake up an entry for comparisons...
720 fill_share_mode((char *)&entry, fsp, 0, 0);
721 return mod_share_mode(fsp->dev, fsp->inode, &entry, downgrade_share_oplock_fn, NULL);
724 /*******************************************************************
725 Get/Set the delete on close flag in a set of share modes.
726 Return False on fail, True on success.
727 ********************************************************************/
729 BOOL modify_delete_flag( SMB_DEV_T dev, SMB_INO_T inode, BOOL delete_on_close)
732 struct locking_data *data;
734 share_mode_entry *shares;
736 /* read in the existing share modes */
737 dbuf = tdb_fetch(tdb, locking_key(dev, inode));
741 data = (struct locking_data *)dbuf.dptr;
742 shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
744 /* Set/Unset the delete on close element. */
745 for (i=0;i<data->num_share_mode_entries;i++,shares++) {
746 shares->share_mode = (delete_on_close ?
747 (shares->share_mode | DELETE_ON_CLOSE_FLAG) :
748 (shares->share_mode & ~DELETE_ON_CLOSE_FLAG) );
752 if (data->num_share_mode_entries) {
753 if (tdb_store(tdb, locking_key(dev,inode), dbuf, TDB_REPLACE)==-1) {
763 /****************************************************************************
764 Traverse the whole database with this function, calling traverse_callback
766 ****************************************************************************/
768 static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf,
771 struct locking_data *data;
772 share_mode_entry *shares;
776 SHAREMODE_FN(traverse_callback) = (SHAREMODE_FN_CAST())state;
778 data = (struct locking_data *)dbuf.dptr;
779 shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data));
780 name = dbuf.dptr + sizeof(*data) + data->num_share_mode_entries*sizeof(*shares);
782 for (i=0;i<data->num_share_mode_entries;i++) {
783 traverse_callback(&shares[i], name);
788 /*******************************************************************
789 Call the specified function on each entry under management by the
791 ********************************************************************/
793 int share_mode_forall(SHAREMODE_FN(fn))
797 return tdb_traverse(tdb, traverse_fn, (void*)fn);